JP2008057501A - Engine oil separator - Google Patents

Abstract

Provided is an engine oil separator that can achieve both the common use of a blow-by gas inlet to a gas chamber and an oil outlet from the gas chamber and an improvement in oil discharge efficiency. To do.
An oil separator 6 includes a first separation chamber 61A provided with a first opening 7A, a second separation chamber 61B provided with a third partition wall 72A, a first separation chamber 61A, and a second separation chamber 61B. And the first partition wall 71A. In addition, a passage connecting the sixth wall portion 86 and the first separation chamber 61A and the second separation chamber 61B, which is connected when the engine oil separated through the third partition wall 72A flows toward the first opening 7A, is provided in the first passage. It is comprised including the passage 62A between rooms. The first inter-chamber passage 62 </ b> A is formed so that the flow velocity of blow-by gas is the smallest in the vicinity of the sixth wall portion 86, while the flow velocity is the largest at a position away from the sixth wall portion 86.
[Selection] Figure 15

Description

  The present invention relates to an engine oil separator for separating oil from blow-by gas.

  A blow-by gas reduction device for reducing blow-by gas to a combustion chamber in an engine has been put into practical use. The blow-by gas reduction device includes a reduction passage for sending blow-by gas in the crankcase into an intake passage, and an oil separator provided in the middle of the passage for separating oil from the blow-by gas.

In general, an oil separator is configured as follows. That is, the oil separator is provided with a gas chamber for moving the blowby gas as a part of the reduction passage, and a partition wall for separating the oil from the gas through contact with the blowby gas. Also, a gas inlet for sending the blow-by gas in the crank chamber to the gas chamber, a gas outlet for sending the gas in the gas chamber to the intake passage, and an oil for sending the oil separated from the blow-by gas out of the gas chamber And an exit. In the oil separator having such a structure, after the blow-by gas in the crank chamber flows into the gas chamber through the gas inlet, the oil is separated from the blow-by gas by collision with the partition wall. The blow-by gas that has collided with the partition wall is sent to the intake passage via the gas outlet, while the separated oil is sent to the crank chamber via the oil outlet. In addition, as an oil separator of the said structure, the oil separator of patent document 1 is mentioned, for example.
JP-A-9-88544 Japanese Utility Model Publication No. 61-97514

  By the way, in an engine provided with a conventional oil separator including the oil separator having the above structure, a passage for sending blow-by gas in the crank chamber into the oil separator, and a passage for sending oil in the oil separator into the crank chamber Must be provided. On the other hand, as the number of passages provided according to the oil separator increases, the structure of the engine becomes more complicated. Therefore, it is desirable to set the number of such passages as small as possible. Therefore, as one proposal for realizing such a demand, the gas inlet and the oil outlet in the oil separator are made common, that is, a passage for sending the blow-by gas of the crank chamber into the oil separator, and the oil separator It is conceivable to use a common passage for sending oil to the crank chamber. However, in this case, there is a problem in that the oil discharge efficiency is lowered because the flow of oil that flows out of the gas chamber is hindered by the flow of blow-by gas flowing into the gas chamber. For this reason, it is desirable to take measures against oil discharge when attempting to make the gas inlet and oil outlet common, but no oil separator with such measures has been proposed so far.

  Incidentally, in the oil separator of Patent Document 2, it is considered that oil separated from blow-by gas in the gas chamber (breather chamber) is returned to the crankcase through the gas inlet. That is, it is considered that the structure in which the gas inlet and the oil outlet proposed above are shared is adopted. However, since no consideration is given to the fact that the flow of oil is hindered by the flow of blow-by gas, there is room for improvement in the oil discharge efficiency.

  The present invention has been made in view of such circumstances, and its purpose is to make the inlet of blow-by gas to the gas chamber common with the outlet of oil from the gas chamber, and to improve oil discharge efficiency. It is an object of the present invention to provide an oil separator for an engine that can achieve both improvement of the above.

In the following, means for achieving the above object and its effects are described.
(1) According to the first aspect of the present invention, the passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber through the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In the engine oil separator configured on the condition that the gas inlet is provided in the gas chamber, the first gas chamber In the gas chamber, a chamber in which the separation wall is provided is a second gas chamber, a portion that partitions the first gas chamber and the second gas chamber is a partition, and the oil separated through the separation wall is A portion connecting when flowing toward the gas inlet is a bottom wall, a passage connecting the first gas chamber and the second gas chamber is an indoor passage, and a flow velocity of blow-by gas in the indoor passage is a gas flow velocity, Regarding the distribution of the gas flow velocity in the longitudinal section of the passage, the indoor passage is formed so that the gas flow velocity is the smallest in the vicinity of the bottom wall while the gas flow velocity is the largest at a position away from the bottom wall. Is the gist.

  According to the invention described in the above claims, since the flow of oil toward the gas inlet is prevented from being blocked by the flow of blow-by gas, the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber It is possible to achieve both the common use of oil and the improvement of oil discharge efficiency. Moreover, since the flow velocity of the blow-by gas at a position away from the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (2) The invention according to claim 2 is characterized in that a passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber via the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In the engine oil separator configured on the condition that the gas inlet is provided in the gas chamber, the chamber is provided with the first gas. A chamber in which the separation wall is provided in the gas chamber is a second gas chamber, a portion that is connected when oil separated through the separation wall flows toward the gas inlet is a bottom wall, and is adjacent to the bottom wall. A space in which an oil flow from the second gas chamber toward the first gas chamber is formed and a space in which a blow-by gas flow from the first gas chamber toward the second gas chamber is formed. A passage is defined as a first indoor passage, and a passage in which a flow of blow-by gas from the first gas chamber toward the second gas chamber is formed at a position farther from the bottom wall than the first indoor passage is a second indoor passage. A plane including a vertical cross section of the first indoor passage and a vertical cross section of the second indoor passage as a reference plane, the area of the first indoor passage is larger than the area of the second indoor passage in the reference plane. Setting It is the subject matter to be.

  According to the invention described in the above claims, the flow rate of the blow-by gas in the first indoor passage, that is, near the bottom wall is reduced, so that the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. Become so. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. In addition, since the flow rate of blow-by gas at a position away from the second indoor passage, that is, the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (3) The invention according to claim 3 is that a passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber through the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In the engine oil separator configured on the condition that the gas inlet is provided in the gas chamber, the first gas chamber The chamber in which the separation wall is provided in the gas chamber is the second gas chamber, the portion that is connected when the oil separated through the separation wall flows toward the gas inlet is the bottom wall, and the first gas chamber The passage connecting the second gas chamber and the second gas chamber is an indoor passage, the width of the indoor passage in the longitudinal section of the indoor passage is the passage width, and the passage width near the bottom wall is larger than the passage width at other positions. The gist is to be set.

  According to the invention described in the above claims, since the flow velocity of the blow-by gas in the vicinity of the bottom wall is reduced, the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. Moreover, since the flow velocity of the blow-by gas at a position away from the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (4) The invention according to claim 4 is the oil separator of the engine according to any one of claims 1 to 3, including the gas inlet, the first gas chamber, the separation wall, and the second gas chamber. The gist is that two sets of the separation structures are provided with the structure as a separation structure.

  (5) The invention according to claim 5 is the oil separator of the engine according to claim 4, wherein, for the two sets of separation structures, one separation structure is a first separation structure and the other separation structure is The body is a second separation structure, the separation wall of the first separation structure is an inter-structure separation wall, and the second gas chamber of the first separation structure and the first of the second separation structure A structure in which a gas chamber is provided at a position adjacent to each other via the structure separation wall and the second gas chamber of the first separation structure and the first gas chamber of the second structure are connected to each other. An interbody passage is formed through the inter-structure separation wall, and oil separated by the inter-structure separation wall flows into the first gas chamber of the second structure through the inter-structure passage. This is the gist.

  (6) The invention according to claim 6 is the engine oil separator according to any one of claims 1 to 5, wherein the volume of the first gas chamber is set smaller than the volume of the second gas chamber. The gist is to be done.

  According to the invention described in the above-mentioned claim, since the volume of the chamber is set small in the vicinity of the gas inlet where the force of the blow-by gas is strong, the gas-liquid separation by the collision of the blow-by gas with the wall forming the first gas chamber is prevented. The effect can be enhanced.

  (7) The invention according to claim 7 is the engine oil separator according to any one of claims 1 to 6, wherein the gas chamber in which the gas outlet is provided is a third gas chamber. The gist is that gas moves in the gas chamber in the order of the first gas chamber, the second gas chamber, and the third gas chamber.

  (8) The invention according to claim 8 is the engine oil separator according to claim 7, wherein the volume of the third gas chamber is set larger than the volumes of the first gas chamber and the second gas chamber. This is the gist.

  According to the invention described in the above-mentioned claim, the volume of the chamber is set near the gas outlet where the stagnation of the flow of blow-by gas is likely to occur compared to the vicinity of the gas inlet. The effect can be enhanced.

  (9) The invention according to claim 9 is characterized in that a passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber through the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In the oil separator of the engine configured on condition that the oil separated through the separation wall is directed toward the gas inlet A portion including the space adjacent to the bottom wall as an indoor passage, and a direction along the first portion in the longitudinal section of the indoor passage as a width direction, the indoor passage A direction perpendicular to the width direction in the vertical cross section is a height direction, a part facing the first part in the height direction is a second part, and the first part and the second part are And the portions facing each other as the third portion and the fourth portion, respectively, and the width of the indoor passage in the longitudinal section of the indoor passage as the passage width, the first portion, the second portion, and the At least one of the second part, the third part, and the fourth part is the first part surrounded by the third part and the fourth part, and at least one of the second part, the third part, and the fourth part is the first part. It is formed to be inclined with respect to one part Through it, the said passage width is set to be smaller as the in the height direction away from said first portion, the oil separator is summarized as a be provided in the cylinder block or crankcase.

  According to the invention described in the above claims, since the flow velocity of the blow-by gas in the vicinity of the first portion is reduced, the flow of oil toward the gas inlet is prevented from being obstructed by the flow of blow-by gas. . Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. In addition, since the flow velocity of the blow-by gas at a position away from the first part is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in the oil discharge efficiency. In addition, since the oil separator is provided at a position close to the crank chamber, the passage connecting the crank chamber and the gas chamber is shortened, so that the oil flowing out of the crank chamber together with the blow-by gas is separated from the blow-by gas earlier. Will come to be. As a result, the amount of oil flowing out of the crank chamber can be reduced.

  (10) The invention according to claim 10 is characterized in that a passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber through the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In an engine oil separator configured on the condition that the oil separated through the separation wall is directed to the gas inlet The portion of the interior passage is defined as the bottom wall, the passage including the space adjacent to the bottom wall as the indoor passage, the flow velocity of blowby gas in the indoor passage as the gas flow velocity, and the gas flow velocity in the longitudinal section of the indoor passage. The gist of the distribution is that the indoor passage is formed such that the gas flow velocity in the vicinity of the bottom wall is smaller than the gas flow velocity at other positions.

  According to the invention described in the above claims, since the flow velocity of the blow-by gas in the vicinity of the bottom wall is reduced, the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. Moreover, since the flow velocity of the blow-by gas at a position away from the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (11) The invention according to claim 11 is characterized in that a passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and blow-by gas to the gas chamber is provided. The oil is separated from the blow-by gas through the contact between the blow-by gas and the separation wall in the course of the flow of the blow-by gas from the gas inlet to the gas outlet, with the gas inlet as the gas inlet and the blow-by gas outlet from the gas chamber as the gas outlet. And the separated oil flows into the crank chamber through the gas inlet and the inlet side passage, with the passage connecting the crank chamber and the gas inlet as the inlet side passage. In an engine oil separator configured on the condition that the oil separated through the separation wall is directed to the gas inlet A portion that connects to the bottom wall, a passage including a space adjacent to the bottom wall as a first indoor passage, and the indoor passage provided at a position farther from the bottom wall than the first indoor passage is a first passage. Two indoor passages are set, and a plane including a longitudinal section of the first indoor passage and the second indoor passage is set as a reference plane, and the area of the first indoor passage is set larger than the area of the second indoor passage in the reference plane. The gist is to be done.

  According to the invention described in the above claims, the flow rate of the blow-by gas in the first indoor passage, that is, near the bottom wall is reduced, so that the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. Become so. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. In addition, since the flow rate of blow-by gas at a position away from the second indoor passage, that is, the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (12) The invention according to claim 12 is the engine oil separator according to any one of claims 1 to 11, wherein an inlet-side separation wall for separating oil from blow-by gas faces the gas inlet. The gist is that it is provided at a position to be used.

  According to the invention described in the above claims, the blow-by gas that has flowed into the gas chamber via the gas inlet collides with the inlet-side separation wall in a state where the flow velocity is high, so that the effect of gas-liquid separation can be enhanced. It becomes like this.

  (13) The gist of the invention described in claim 13 is an engine provided with the oil separator according to any one of claims 1-12.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In the present embodiment, it is assumed that the present invention is embodied as an oil separator provided in a cylinder block.

[1] "Engine structure"
The structure of the engine 1 will be described with reference to FIGS. 1 to 3 show the structure of the engine 1 in which each component is appropriately omitted.

  The engine 1 includes an engine main body 11 for obtaining power through combustion of a mixture of air and fuel, and an intake device 3 for supplying external air to the engine main body 11. Further, the blow-by gas is reduced to the combustion chamber 41R, and the blow-by gas reducing device 5 for separating engine oil from the blow-by gas is included.

  The engine body 11 includes a cylinder block 4 for burning the air-fuel mixture in each cylinder 41, a crankcase 12 for arranging the crankshaft 21, and an oil pan 13 for storing engine oil. Has been. In addition, the cylinder head 14 is configured to dispose the valve system components, the head cover 15 is configured to suppress scattering of the engine oil, and the chain cover 16 is used to block the operation sound of the timing chain 22. ing. In the present embodiment, the arrangement direction of the cylinders 41 is the length direction EX of the engine 1. A direction along the center line of the cylinder 41 is defined as a height direction EY of the engine 1. Further, a direction orthogonal to the length direction EX and the height direction EY is defined as a width direction EZ of the engine 1.

  The cylinder block 4 is roughly divided into an upper block 4A in which a cylinder 41 is provided and a lower block 4B in which a crank chamber 42 is provided. The upper block 4A is provided with a first cylinder 41A, a second cylinder 41B, a third cylinder 41C, and a fourth cylinder 41D as cylinders 41. The lower block 4B includes, as the crank chamber 42, a first crank chamber 42A corresponding to the first cylinder 41A, a second crank chamber 42B corresponding to the second cylinder 41B, and a third crank chamber corresponding to the third cylinder 41C. 42C and a fourth crank chamber 42D corresponding to the fourth cylinder 41D are provided. In the engine main body 11, a main body crank chamber 11 </ b> A for housing the crankshaft 21 is formed by the crank chamber 42 of the cylinder block 4 and the crank chamber 12 </ b> A of the crankcase 12.

  A timing chain 22 is wound around the crankshaft 21 for transmitting torque to each device of the engine 1. A connecting rod 24 for converting the reciprocating motion of the piston 23 into the rotational motion of the crankshaft 21 is attached to each cylinder 41.

  The cylinder head 14 is provided with an intake valve 25 for opening and closing the intake port 14A of each cylinder 41 with respect to the combustion chamber, and an intake cam shaft 27 for driving each intake valve 25. In addition, an exhaust valve 26 for opening and closing the exhaust port 14B of each cylinder 41 with respect to the combustion chamber, and an exhaust camshaft 28 for driving each exhaust valve 26 are provided. In addition, an injector 29 for injecting fuel to each intake port 14A is provided. The intake camshaft 27 and the exhaust camshaft 28 are driven by the torque of the crankshaft 21 transmitted via the timing chain 22.

  The intake device 3 includes an air cleaner 32 for capturing foreign matter contained in air by an air element 32A, a throttle body 34 for adjusting the flow rate of air in the intake device 3 through an opening / closing operation of the throttle valve 34A, An intake manifold 35 for sending the air in the apparatus 3 to each intake port 14A is included. The air intake 31 for taking outside air into the intake device 3 and the intake hose 33 for connecting the air cleaner 32 and the throttle body 34 are included. The intake manifold 35 is provided with a surge tank 35A for retaining air that has passed through the throttle body 34, and a plurality of sub-pipes 35B for sending the air in the surge tank 35A to each intake port 14A.

  In the intake device 3, the outside air is passed through the engine body by the passage in the air intake 31, the passage in the air cleaner 32, the passage in the intake hose 33, the passage in the throttle body 34, and the passage in the intake manifold 35. 11 is formed. The intake passage 36 is divided as follows based on the air element 32A and the throttle valve 34A. That is, the first intake passage 36A on the upstream side (outside air side) from the air element 32A, the second intake passage 36B between the air element 32A and the throttle valve 34A, and the downstream side (engine body 11). Side) third intake passage 36C.

[2] “Blow-by gas reduction device structure”
With reference to FIG.2 and FIG.3, the structure of the blowby gas reduction apparatus 5 is demonstrated.
The blow-by gas reduction device 5 has a function for sending blow-by gas from the main body crank chamber 11A to the intake device 3 (third intake passage 36C), and a function for sending air purified by the air cleaner 32 to the main body crank chamber 11A. The apparatus has a function for separating engine oil from blow-by gas. That is, the one-way passage 51 for sending the blow-by gas of the main body crank chamber 11A to the third intake passage 36C, the two-way passage 52 for sending the air of the second intake passage 36B to the main body crank chamber 11A, and the blow-by gas An oil separator 6 for separating engine oil is included. Also, a first tube 53 for forming the one-way passage 51, a second tube 54 for forming the two-way passage 52, and a control valve 55 for adjusting the flow rate of blow-by gas in the one-way passage 51, It is comprised including.

  The first tube 53 has one opening connected to the oil separator 6 and the other opening connected to the surge tank 35A. The second tube 54 has one opening connected to the intake hose 33 and the other opening connected to the head cover 15. The control valve 55 is configured as a mechanical valve whose internal passage area is changed according to the negative pressure of the third intake passage 36C. Specifically, the internal passage area is expanded as the negative pressure of the third intake passage 36C decreases, that is, the flow rate of the gas passing through the control valve 55 is increased.

  The one-way passage 51 is formed by a main body passage 43 provided in the cylinder block 4, a separation chamber 61 provided in the oil separator 6, and a pipe passage 53 </ b> A provided in the first tube 53. . The cylinder block 4 is provided with a first main body passage 43 </ b> A and a second main body passage 43 </ b> B for moving the blow-by gas between the main body crank chamber 11 </ b> A and the oil separator 6 as the main body passage 43. .

  The two-way passage 52 is formed by an in-pipe passage 54A provided in the second tube 54, an in-cover passage 15A provided in the head cover 15, and an in-cover passage 16A provided in the chain cover 16. Yes. The function of the two-way passage 52 is changed as follows according to the load of the engine 1. That is, the two-way passage 52 functions as a passage for sending the air in the second intake passage 36B to the main crank chamber 11A as described above when the engine 1 is under a low load, while the main body crank when the engine 1 is under a high load. It functions as a passage for sending the blow-by gas in the chamber 11A into the second intake passage 36B.

  The oil separator 6 includes a separator body 7 formed as a part of the cylinder block 4, a separator cover 9 formed separately from the separator body 7, and a bolt 63 for fixing the separator cover 9 to the separator body 7. It is comprised including. A separation chamber 61 for separating engine oil from blow-by gas is formed between the separator body 7 and the separator cover 9. Further, the space between the separator body 7 and the separator cover 9 is sealed so that the gas in the separation chamber 61 does not leak to the outside.

[3] “Gas flow in blow-by gas reduction device”
With reference to FIG.4 and FIG.5, the flow of the gas in the blowby gas reduction apparatus 5 is demonstrated. 4 shows the gas flow when the engine 1 is under a low load, and FIG. 5 shows the gas flow when the engine 1 is under a high load.

  (A) When the engine 1 is under a low load, that is, when the negative pressure in the third intake passage 36C is large, the following gas flow is formed in the blow-by gas reduction device 5. The blow-by gas in the vicinity of the boundary between the second crank chamber 42B and the third crank chamber 42C causes the first main body passage 43A of the cylinder block 4, the separation chamber 61 of the oil separator 6, the in-pipe passage 53A of the first tube 53, and the intake manifold 35. Flow in the blow-by gas reduction device 5 in the order of the surge tank 35A. The blow-by gas in the vicinity of the boundary between the first crank chamber 42A and the second crank chamber 42B causes the second main body passage 43B of the cylinder block 4, the separation chamber 61 of the oil separator 6, the in-pipe passage 53A of the first tube 53, and the intake. It flows through the blow-by gas reduction device 5 in the order of the surge tank 35A of the manifold 35. Further, the air in the intake hose 33 is blow-by gas reduction device in the order of the in-pipe passage 54A of the second tube 54, the in-cover passage 15A of the head cover 15, the in-cover passage 16A of the chain cover 16, and the main body crank chamber 11A of the engine body 11. Flowing through 5 Thus, when the engine 1 is under a low load, the blow-by gas in the main body crank chamber 11A is sent into the intake manifold 35, while the air purified by the air cleaner 32 is sent into the main body crank chamber 11A.

  (B) When the engine 1 is under a high load, that is, when the negative pressure in the third intake passage 36C is small, the following gas flow is formed in the blow-by gas reduction device 5. The blow-by gas in the vicinity of the boundary between the second crank chamber 42B and the third crank chamber 42C causes the first main body passage 43A of the cylinder block 4, the separation chamber 61 of the oil separator 6, the in-pipe passage 53A of the first tube 53, and the intake manifold 35. Flow in the blow-by gas reduction device 5 in the order of the surge tank 35A. The blow-by gas in the vicinity of the boundary between the first crank chamber 42A and the second crank chamber 42B causes the second main body passage 43B of the cylinder block 4, the separation chamber 61 of the oil separator 6, the in-pipe passage 53A of the first tube 53, and the intake. It flows through the blow-by gas reduction device 5 in the order of the surge tank 35A of the manifold 35. Further, the blow-by gas in the vicinity of the fourth crank chamber 42D flows in the blow-by gas reduction device 5 in the order of the in-cover passage 16A of the chain cover 16, the in-cover passage 15A of the head cover 15, the in-pipe passage 54A of the second tube 54 and the intake hose 33 Flowing. In this way, when the engine 1 is under a heavy load, the blow-by gas in the main body crank chamber 11A is sent into the intake manifold 35 through the one-way passage 51 and into the intake hose 33 through the two-way passage 52. It is.

[4] “Cylinder block structure”
A detailed structure of the cylinder block 4 will be described with reference to FIGS. FIG. 6 shows a perspective structure of the cylinder block 4 with the separator cover 9 attached thereto. FIG. 7 shows a perspective structure of the cylinder block 4 with the separator cover 9 removed. FIG. 8 shows the front structure of the cylinder block 4 as seen from the VA direction of FIG. FIG. 9 shows a front structure of the cylinder block 4 as viewed from the VA direction of FIG.

  The cylinder block 4 is provided with a plurality of flanges 44 for attaching the elements constituting the engine 1 and the vehicle. That is, as the flange 44, a first flange 44A for attaching the cylinder head 14, a second flange 44B for attaching the crankcase 12, a third flange 44C for attaching the chain cover 16, and a transmission. A fourth flange 44D is provided.

  The upper block 4 </ b> A is provided with a plurality of horizontal ribs 45 and vertical ribs 46 for reinforcing the cylinder block 4. That is, as the lateral rib 45, a first lateral rib 45A, a second lateral rib 45B, a third lateral rib 45C, and a fourth lateral rib 45D extending in the length direction EX are provided. Further, as the vertical ribs 46, a first vertical rib 46A, a second vertical rib 46B, a third vertical rib 46C and a fourth vertical rib 46D extending in the height direction EY are provided.

  The first horizontal rib 45A is provided in the vicinity of the first flange 44A in the height direction EY. Moreover, in the length direction EX, it is provided between a position corresponding to between the first cylinder 41A and the fourth flange 44D and a position corresponding to between the fourth cylinder 41D and the third flange 44C. . The second horizontal rib 45B is provided in the vicinity of the boundary between the upper block 4A and the lower block 4B in the height direction EY. Moreover, in the length direction EX, it is provided between a position corresponding to between the first cylinder 41A and the fourth flange 44D and a position corresponding to between the fourth cylinder 41D and the third flange 44C. . The third lateral rib 45C is provided between the first lateral rib 45A and the second lateral rib 45B in the height direction EY. Moreover, in the length direction EX, it is provided between a position corresponding to between the first cylinder 41A and the fourth flange 44D and a position corresponding to between the fourth cylinder 41D and the third flange 44C. . The fourth horizontal rib 45D is provided between the first horizontal rib 45A and the third horizontal rib 45C in the height direction EY. Further, it is provided between the first vertical rib 46A and the second vertical rib 46B in the length direction EX.

  The first vertical rib 46A is provided at a position corresponding to between the first cylinder 41A and the fourth flange 44D in the length direction EX. Further, it is provided between the first flange 44A and the third lateral rib 45C in the height direction EY. The second vertical rib 46B is provided at a position corresponding to between the first cylinder 41A and the second cylinder 41B in the length direction EX. Further, it is provided between the first flange 44A and the third lateral rib 45C in the height direction EY. The third vertical rib 46C is provided at a position corresponding to between the second cylinder 41B and the third cylinder 41C in the length direction EX. Further, it is provided between the first flange 44A and the third lateral rib 45C in the height direction EY. The fourth vertical rib 46D is provided at a position corresponding to between the third cylinder 41C and the fourth cylinder 41D in the length direction EX. Further, it is provided between the first flange 44A and the third lateral rib 45C in the height direction EY.

  The lower block 4 </ b> B is provided with a plurality of vertical ribs 47 for reinforcing the cylinder block 4. That is, as the vertical ribs 47, a fifth vertical rib 47A, a sixth vertical rib 47B, and a seventh vertical rib 47C extending in the height direction EY in the front view (VA view) of the cylinder block 4 are provided.

  The fifth vertical rib 47A is provided at a position corresponding to between the first cylinder 41A and the second cylinder 41B in the length direction EX. Further, it is provided between the second lateral rib 45B and the second flange 44B in the height direction EY. The sixth vertical rib 47B is provided at a position corresponding to between the second cylinder 41B and the third cylinder 41C in the length direction EX. Further, it is provided between the second lateral rib 45B and the second flange 44B in the height direction EY. The seventh vertical rib 47C is provided at a position corresponding to between the third cylinder 41C and the fourth cylinder 41D in the length direction EX. Further, it is provided between the second lateral rib 45B and the second flange 44B in the height direction EY.

  Outside the cylinder block 4, a main body peripheral wall 8, a first main body inner wall 71, and a second main body inner wall 72 constituting the separator main body 7 of the oil separator 6 are provided in accordance with the ribs. The main body peripheral wall 8, the first main body inner wall 71, and the second main body inner wall 72 are provided so as to protrude from the outer wall of the cylinder block 4 in the width direction EZ. Further, it is formed integrally with each rib of the cylinder block 4. The main body peripheral wall 8 is provided with a first opening 7A corresponding to the first main body passage 43A and a second opening 7B corresponding to the second main body passage 43B.

  The structure of the first main body passage 43A and the second main body passage 43B will be described with reference to FIGS. FIG. 10 shows a cross-sectional structure of the cylinder block 4 along the DA-DA line in FIGS. 8 and 9. FIG. 11 shows a cross-sectional structure of the cylinder block 4 along the DB-DB line in FIGS. 8 and 9.

  The first main body passage 43 </ b> A is provided in the cylinder block 4 as a passage connecting the main body crank chamber 11 </ b> A (crank chamber 12 </ b> A) and the first opening 7 </ b> A of the main body peripheral wall 8. Specifically, the second crank chamber 42B and the third crank chamber 42C are provided so as to pass through the partition wall of the cylinder block 4 and the sixth vertical rib 47B.

  The second main body passage 43 </ b> B is provided in the cylinder block 4 as a passage connecting the main body crank chamber 11 </ b> A (crank chamber 12 </ b> A) and the second opening 7 </ b> B of the main body peripheral wall 8. Specifically, the first crank chamber 42A and the second crank chamber 42B are provided so as to pass through the partition wall of the cylinder block 4 and the fifth vertical rib 47A.

[5] “Structure 1 of oil separator”
The structure of the oil separator 6 will be described with reference to FIGS. 9 and 12 to 14. 12 to 14 show the front structure of the oil separator 6 as viewed from the VA direction in FIG.

  The separator body 7 is provided in a range surrounded by a main body peripheral wall 8 provided on the outer wall of the cylinder block 4, an outer wall (main body side wall 73) of the cylinder block 4 located in a range surrounded by the main body peripheral wall 8, and the main body peripheral wall 8. The first main body inner wall 71 and the second main body inner wall 72 are formed.

  The main body peripheral wall 8 includes a first main body peripheral wall 8A and a second main body peripheral wall 8B that connect the first horizontal rib 45A and the second horizontal rib 45B, a third main body peripheral wall 8C formed integrally with the first horizontal rib 45A, It is comprised by the 4th main body surrounding wall 8D formed integrally with the 2nd horizontal rib 45B.

  The first main body peripheral wall 8A has a portion corresponding to the vicinity of the center of the second cylinder 41B in the first horizontal rib 45A, and a portion positioned in the vicinity of the boundary between the third cylinder 41C and the sixth vertical rib 47B in the second horizontal rib 45B. It is formed to connect Further, it is formed including a portion that bends across the sixth vertical rib 47B.

  The second main body peripheral wall 8B is formed to connect a portion of the first horizontal rib 45A corresponding to the vicinity of the center of the first cylinder 41A and a portion of the second horizontal rib 45B corresponding to the vicinity of the center of the first cylinder 41A. ing. Further, the first horizontal rib 45A and the third horizontal rib 45C are curved so as to bulge toward the first vertical rib 46A.

  The third main body peripheral wall 8C is formed between the first main body peripheral wall 8A and the second main body peripheral wall 8B in the first lateral rib 45A. Further, the first horizontal rib 45A is formed so as to protrude in the width direction EZ from a portion not included in the third main body peripheral wall 8C.

  The fourth main body peripheral wall 8D is formed between the first main body peripheral wall 8A and the second main body peripheral wall 8B in the second lateral rib 45B. Further, the second horizontal rib 45B is formed so as to protrude in the width direction EZ from a portion not included in the fourth main body peripheral wall 8D. Moreover, it forms including the site | part which inclines toward the bottom part from the top part of the cylinder block 4 as it leaves | separates from the cylinder block 4 in the width direction EZ.

  The first main body inner wall 71 includes a first partition wall 71A and a second partition wall 71B. The first partition wall 71A is formed so as to connect a portion bent in the first main body peripheral wall 8A and the second main body peripheral wall 8B side in the vicinity of the first opening 7A in the fourth main body peripheral wall 8D. Further, it is formed along the height direction EY. The second partition wall 71B is formed in the third horizontal rib 45C between a portion where the first partition wall 71A is provided and a portion corresponding to the vicinity of the center of the second cylinder 41B. Moreover, it is formed along the length direction EX.

  The second main body inner wall 72 includes a third partition wall 72A, a fourth partition wall 72B, a fifth partition wall 72C, and a sixth partition wall 72D. The third partition wall 72A is formed so as to connect the second main body peripheral wall 8B side in the vicinity of the second opening 7B in the fourth main body peripheral wall 8D and the third horizontal rib 45C. Further, it is formed along the height direction EY. The fourth partition wall 72B is formed so as to be connected to the third horizontal rib 45C and the fourth horizontal rib 45D. Further, it is formed along the second vertical rib 46B. The fifth partition wall 72C is connected to the third partition wall 72A and the sixth partition wall 72D and is formed integrally with the third horizontal rib 45C. Moreover, it is formed along the length direction EX. The sixth partition wall 72D is formed to connect the first main body peripheral wall 8A side near the second opening 7B in the fourth main body peripheral wall 8D and the third horizontal rib 45C. Further, it is formed along the height direction EY.

  A plurality of bosses 74 for screwing the bolts 63 are provided around the main body peripheral wall 8. That is, as the boss 74, the first boss 74A and the eighth boss 74H formed continuously with the first main body peripheral wall 8A, the second boss 74B formed continuously with the third main body peripheral wall 8C, and the third main body. A third boss 74C formed continuously with the peripheral wall 8C and the second main body peripheral wall 8B is provided. Also, a fourth boss 74D formed continuously with the second main body peripheral wall 8B, a fifth boss 74E formed continuously with the second main body peripheral wall 8B and the fourth main body peripheral wall 8D, and a fourth main body peripheral wall 8D A sixth boss 74F formed continuously is provided. Also, a seventh boss 74G formed continuously with the fourth main body peripheral wall 8D and the first main body peripheral wall 8A is provided. Each boss 74 is provided with a bolt hole 75 corresponding to the bolt 63.

  The main body peripheral wall 8 is divided into the following wall portions based on the bosses 74. That is, the first wall 81, the second wall 82, the third wall 83, the fourth wall 84, the fifth wall 85, the sixth wall 86, and the seventh wall 87 are divided.

  The first wall portion 81 includes a portion located between the first boss 74A and the second boss 74B in the main body peripheral wall 8. The second wall portion 82 includes a portion located between the second boss 74B and the third boss 74C in the main body peripheral wall 8. The third wall portion 83 includes a portion of the main body peripheral wall 8 located between the third boss 74C and the fourth boss 74D. The fourth wall portion 84 includes a portion located between the fourth boss 74D and the fifth boss 74E in the main body peripheral wall 8. The fifth wall portion 85 includes a portion of the main body peripheral wall 8 that is located between the fifth boss 74E and the sixth boss 74F. The sixth wall portion 86 includes a portion located between the sixth boss 74F and the seventh boss 74G in the main body peripheral wall 8. The seventh wall portion 87 includes a portion located between the seventh boss 74G and the eighth boss 74H in the main body peripheral wall 8. The eighth wall portion 88 includes a portion located between the eighth boss 74H and the first boss 74A in the main body peripheral wall 8.

  More precisely, the ranges of the fifth wall portion 85 and the sixth wall portion 86 can be expressed as follows. That is, the connection part is a portion where the fourth main body peripheral wall 8D and the sixth partition wall 72D are connected, and the fifth wall 85 is located between the fifth boss 74E and the same connection part of the main body peripheral wall 8. A site is included. Further, the sixth wall portion 86 includes a portion of the main body peripheral wall 8 that is located between the connection portion and the seventh boss 74G.

  The separator cover 9 is provided with a valve mounting seat 91 for mounting the control valve 55. Moreover, the bolt hole 92 is provided in the position corresponding to the bolt hole 75 of each boss | hub 74 of the separator main body 7 (refer FIG. 7). In the oil separator 6 of the present embodiment, a first separation structure is formed including the first opening 7A, the first separation chamber 61A, the second separation chamber 61B, and the sixth partition wall 72D. A second separation structure is formed including the second opening 7B, the fourth separation chamber 61D, the fifth separation chamber 61E, and the fourth wall portion 84.

[6] “Structure 2 of oil separator”
With reference to FIG. 15, the chamber and passage formed in the oil separator 6 will be described.
The separation chamber 61 of the oil separator 6 is partitioned into the following chambers through the first main body inner wall 71 and the second main body inner wall 72. That is, the first separation chamber 61A, the second separation chamber 61B, the third separation chamber 61C, and the third separation chamber 61C, which form a blow-by gas passage between the first opening 7A and the control valve 55, include the third separation chamber 61C. It is divided into a fourth separation chamber 61D, a fifth separation chamber 61E, and a sixth separation chamber 61F that form a blow-by gas passage between the two openings 7B and the control valve 55.

  The first separation chamber 61A is formed to be surrounded by the sixth wall portion 86, the seventh wall portion 87, and the first partition wall 71A. The second separation chamber 61B is formed so as to be surrounded by the sixth wall 86, the first partition 71A, the second partition 71B, the third horizontal rib 45C, and the sixth partition 72D. The third separation chamber 61C is formed to be surrounded by the second partition wall 71B, the eighth wall portion 88, the first wall portion 81, the fourth partition wall 72B, the fifth partition wall 72C, and the third horizontal rib 45C. The fourth separation chamber 61D is formed to be surrounded by the fifth wall portion 85, the sixth partition wall 72D, the fifth partition wall 72C, and the third partition wall 72A. The fifth separation chamber 61E is formed to be surrounded by the fifth wall portion 85, the third partition wall 72A, the third lateral rib 45C, and the fourth wall portion 84. The sixth separation chamber 61F is formed to be surrounded by the third horizontal rib 45C, the fourth partition wall 72B, the second wall portion 82, and the third wall portion 83.

  In the separation chamber 61 of the oil separator 6, passages (inter-chamber passages 62) that connect the separation chambers are formed. That is, as the inter-chamber passage 62, the first inter-chamber passage 62A, the third inter-chamber passage 62C, the second inter-chamber passage 62B, the fourth inter-chamber passage 62D, the fifth inter-chamber passage 62E, and the sixth inter-chamber passage 62F Is formed.

  The first inter-chamber passage 62A is formed as a passage connecting the first separation chamber 61A and the second separation chamber 61B via the first partition wall 71A. The second inter-chamber passage 62B is formed as a passage connecting the fourth separation chamber 61D and the fifth separation chamber 61E via the third partition wall 72A. The third inter-chamber passage 62C is formed as a passage connecting the second separation chamber 61B and the third separation chamber 61C via the third lateral rib 45C. The fourth inter-chamber passage 62D is formed as a passage connecting the fifth separation chamber 61E and the sixth separation chamber 61F via the third lateral rib 45C. The fifth inter-chamber passage 62E is formed as a passage connecting the sixth separation chamber 61F and the third separation chamber 61C via the fourth partition wall 72B. The sixth inter-chamber passage 62F is formed as a passage connecting the second separation chamber 61B and the fourth separation chamber 61D via the sixth partition wall 72D.

[7] “Flow of blow-by gas and engine oil in the oil separator 1”
Referring to FIG. 16, the blow-by gas when the flow rate of blow-by gas flowing into oil separator 6 is in a standard size state or smaller than that (high negative pressure state) is maintained. The flow of engine oil will be described.

  In the one-way passage 51 of the blow-by gas reduction device 5, the following two flows are mainly formed as the flow of blow-by gas between the crank chamber 42 and the control valve 55. That is, after flowing into the oil separator 6 through the first main body passage 43A, the first flow that moves in the oil separator 6 in the order of the first separation chamber 61A, the second separation chamber 61B, and the third separation chamber 61C; After flowing into the oil separator 6 through the second main body passage 43B, the oil separator 6 moves in the order of the fourth separation chamber 61D, the fifth separation chamber 61E, the sixth separation chamber 61F, and the third separation chamber 61C. A second flow is formed. More precisely, the first flow and the second flow can be expressed as follows. That is, the first flow includes the first main body passage 43A, the first opening 7A, the first separation chamber 61A, the first inter-chamber passage 62A, the second separation chamber 61B, the third inter-chamber passage 62C, and the third separation chamber. The flow of blow-by gas flowing into the control valve 55 after moving through the one-way passage 51 in the order of 61C is shown. The second flow is the second main body passage 43B, the second opening 7B, the fourth separation chamber 61D, the second inter-chamber passage 62B, the fifth separation chamber 61E, the fourth inter-chamber passage 62D, and the sixth separation chamber. The flow of the blow-by gas flowing into the control valve 55 after moving the one-way passage 51 in the order of 61F, the fifth inter-chamber passage 62E, and the third separation chamber 61C is shown.

  In the first flow, engine oil is separated from blow-by gas as follows. The blow-by gas in the crank chamber 42 is drawn from the crank chamber 42 into the first main body passage 43 </ b> A by the negative pressure in the intake manifold 35. The gas in the first main body passage 43A flows into the first separation chamber 61A of the oil separator 6 through the first opening 7A. Part of the blow-by gas that has flowed into the first separation chamber 61 </ b> A collides with the seventh wall portion 87. At this time, the engine oil in the blow-by gas is separated from the blow-by gas due to the collision with the seventh wall portion 87, and then moves to the sixth wall portion 86 (first opening portion 7A) side by gravity. The blow-by gas that has collided with the seventh wall 87 changes the flow direction and flows into the second separation chamber 61B. Part of the blow-by gas that has flowed into the second separation chamber 61B collides with the sixth partition wall 72D. At this time, the engine oil in the blow-by gas is separated from the blow-by gas due to the collision with the sixth partition wall 72D, and then moves to the sixth wall 86 side by gravity. The blow-by gas that has collided with the sixth partition wall 72D changes the flow direction and flows into the third separation chamber 61C. The blow-by gas that has flowed into the third separation chamber 61C flows into the in-pipe passage 53A via the control valve 55. Since the third separation chamber 61C has a larger volume than the first separation chamber 61A and the second separation chamber 61B, the stagnation of the flow of blow-by gas occurs in a wide range of the third separation chamber 61C. . When the blow-by gas stays in the third separation chamber 61C, the engine oil is separated from the blow-by gas by gravity. The engine oil separated from the blow-by gas in the second separation chamber 61B and the third separation chamber 61C basically flows toward the first opening 7A while connecting the sixth wall portion 86. That is, after moving on the sixth wall 86 in the order of the second separation chamber 61B, the first inter-chamber passage 62A, and the first separation chamber 61A, it flows into the first main body passage 43A through the first opening 7A. The engine oil that has flowed into the first main body passage 43A moves through the first main body passage 43A in opposition to the flow of blow-by gas, and then flows into the crank chamber 42. Thus, in the oil separator 6, the blow-by gas inlet to the separation chamber 61 and the engine oil outlet from the separation chamber 61 are common. That is, the blow-by gas reduction device 5 is configured such that the first opening 7A functions as an inlet for blow-by gas and an outlet for engine oil.

  In the second flow, engine oil is separated from blow-by gas as follows. The blow-by gas in the crank chamber 42 is drawn from the crank chamber 42 into the second main body passage 43 </ b> B by the negative pressure in the intake manifold 35. The gas in the second main body passage 43B flows into the fourth separation chamber 61D of the oil separator 6 through the second opening 7B. Part of the blow-by gas that has flowed into the fourth separation chamber 61D collides with the fifth partition wall 72C. At this time, the engine oil in the blow-by gas is separated from the blow-by gas due to the collision with the fifth partition wall 72C, and then moves to the fifth wall 85 (second opening 7B) by gravity. The blow-by gas that has collided with the fifth partition wall 72C changes the flow direction and flows into the fifth separation chamber 61E. Part of the blow-by gas that has flowed into the fifth separation chamber 61 </ b> E collides with the fourth wall portion 84. At this time, the engine oil in the blow-by gas is separated from the blow-by gas due to the collision with the fourth wall portion 84 and then moves to the fifth wall portion 85 side by gravity. The blow-by gas that has collided with the fourth wall portion 84 changes the flow direction and flows into the sixth separation chamber 61F. Part of the blow-by gas that has flowed into the sixth separation chamber 61F collides with the second wall portion 82. At this time, the oil in the blow-by gas is separated from the blow-by gas due to the collision with the second wall portion 82 and then moves to the fifth wall portion 85 side by gravity. The blow-by gas that has collided with the second wall 82 changes the flow direction and flows into the third separation chamber 61C. The blow-by gas that has flowed into the third separation chamber 61C flows into the in-pipe passage 53A via the control valve 55. Since the third separation chamber 61C has a larger volume than the fourth separation chamber 61D, the fifth separation chamber 61E, and the sixth separation chamber 61F, the flow of the blow-by gas is wide in the third separation chamber 61C. Stagnation begins to occur. When the blow-by gas stays in the third separation chamber 61C, the engine oil is separated from the blow-by gas by gravity. The engine oil separated from the blow-by gas in the fifth separation chamber 61E and the sixth separation chamber 61F basically flows toward the second opening 7B while connecting the fifth wall 85. That is, after moving on the fifth wall 85 in the order of the fifth separation chamber 61E, the second inter-chamber passage 62B, and the fourth separation chamber 61D, it flows into the second main body passage 43B through the second opening 7B. The engine oil that has flowed into the second main body passage 43B moves through the second main body passage 43B in opposition to the flow of blow-by gas, and then flows into the crank chamber 42. Thus, in the oil separator 6, the blow-by gas inlet to the separation chamber 61 and the engine oil outlet from the separation chamber 61 are common. That is, the blow-by gas reduction device 5 is configured such that the second opening 7B functions as a blow-by gas inlet and an engine oil outlet.

[8] “Shape of the passage between rooms”
With reference to FIG. 17, the shape of 62 A of 1st chamber passages is demonstrated. FIG. 17 shows a cross-sectional structure of the oil separator 6 along the DC-DC line in FIGS. 12 and 13.

  Here, a part of the main body peripheral wall 8 that is separated when the engine oil separated in the separation chamber 61 flows toward the first opening 7A or the second opening 7B, that is, the fourth main body peripheral wall 8D (fifth wall 85). The sixth wall portion 86) is the main body bottom wall 80. A longitudinal section of the first chamber passage 62A is defined as a first passage section FA. A plane including the first passage section FA is defined as a first reference plane FB. Further, the direction along the main body bottom wall 80 in the first passage section FA is defined as the width direction GZ of the first chamber passage 62A, and the direction perpendicular to the width direction GZ in the first passage section FA is the height of the first chamber passage 62A. The vertical direction is GY. The width of the first inter-chamber passage 62A in the first passage cross section FA is defined as a first passage width WA. The flow rate of blow-by gas in the first inter-chamber passage 62A is defined as a first gas flow rate VX. Note that the sectional structure shown in FIG. 17 corresponds to the sectional structure of the oil separator 6 belonging to the first reference plane FB, that is, the sectional structure of the oil separator 6 including the first passage section FA. Further, the first reference plane FB includes a longitudinal section of the first partition wall 71A.

  The first inter-chamber passage 62 </ b> A is formed by being surrounded by the main body bottom wall 80 (sixth wall portion 86), the first partition wall 71 </ b> A, and the separator cover 9. Further, the first passage width WA is the largest in the vicinity of the main body bottom wall 80, while the first passage width WA is the smallest at a position farthest from the main body bottom wall 80 in the height direction GY. Has been. Further, the position where the first passage width WA is set to be the largest is used as the reference position, and the first passage width WA is gradually reduced as the distance from the main body bottom wall 80 and the reference position in the height direction GY increases. ing.

  Thereby, regarding the distribution of the first gas flow velocity VX in the first passage cross section FA, the first gas flow velocity VX is the smallest in the vicinity of the main body bottom wall 80, while the first gas flow velocity VX is at a position away from the main body bottom wall 80. VX is the largest. That is, in the first passage section FA, the first gas flow velocity VX becomes the smallest in the vicinity of the main body bottom wall 80 where the engine oil flows toward the first opening 7A, while the engine oil flowing toward the first opening 7A The first gas flow velocity VX becomes the largest at a position where the influence on the flow is small.

  The shape of the first inter-chamber passage 62A is such that the main body bottom wall 80 is formed along the width direction GZ on the first reference plane FB, and a part of the first partition wall 71A and the separator cover 9 are high. This is realized based on being formed along the direction GY and being formed so that a part of the first partition wall 71 </ b> A is inclined with respect to the main body bottom wall 80. The first partition 71A is specifically formed as follows, with the surface facing the separator cover 9 as the partition side surface 71AF. That is, the upper partition wall 71AA is formed so that the partition wall side surface 71AF is inclined with respect to the main body bottom wall 80 and the separator cover 9 in the first reference plane FB, and the partition wall side surface 71AF is along the separator cover 9 in the first reference plane FB. The lower partition wall 71AB is formed as described above. Based on the structure of the first partition wall 71A, the formation mode of the first inter-chamber passage 62A can also be expressed as follows. That is, the first inter-chamber passage 62A connects the main body bottom wall 80 and the upper partition wall 71AA on the first reference plane FB and faces the lower partition wall 71AB and the separator cover 9 and the upper partition wall 71AA facing the body bottom wall 80. And the bottom wall 80 of the main body.

The shape of the second inter-chamber passage 62B will be described with reference to FIG. FIG. 18 shows a cross-sectional structure of the oil separator 6 along the line DD-DD in FIGS. 12 and 13.
Here, a longitudinal section of the second inter-chamber passage 62B is defined as a second passage cross section FC. A plane including the second passage section FC is defined as a second reference plane FD. Further, the direction along the main body bottom wall 80 in the second passage section FC is defined as the width direction GZ of the second chamber passage 62B, and the direction orthogonal to the width direction GZ in the second passage section FC is the height of the second chamber passage 62B. The vertical direction is GY. Further, the width of the second inter-chamber passage 62B in the second passage cross section FC is defined as a second passage width WB. In addition, the flow rate of blow-by gas in the second inter-chamber passage 62B is set as the second gas flow rate VY. 18 corresponds to the sectional structure of the oil separator 6 belonging to the second reference plane FD, that is, the sectional structure of the oil separator 6 including the second passage section FC. The second reference plane FD also includes a longitudinal section of the third partition wall 72A.

  The second inter-chamber passage 62B is formed to be surrounded by the main body bottom wall 80 (fifth wall portion 85), the third partition wall 72A, and the separator cover 9. Further, the second passage width WB is the largest in the vicinity of the main body bottom wall 80, while the second passage width WB is the smallest at the position farthest from the main body bottom wall 80 in the height direction GY. Has been. Further, the position where the second passage width WB is set to be the largest is used as the reference position, and the second passage width WB is gradually reduced as the distance from the main body bottom wall 80 and the reference position in the height direction GY increases. ing.

  As a result, regarding the distribution of the second gas flow velocity VY in the second passage cross section FC, the second gas flow velocity VY is the smallest in the vicinity of the main body bottom wall 80, while the second gas flow velocity VY is at a position away from the main body bottom wall 80. VY is the largest. That is, in the vicinity of the bottom wall 80 of the main body where the engine oil flows toward the second opening 7B, the second gas flow velocity VY is the smallest, but at a position where the influence on the flow of the engine oil toward the second opening 7B is small. The second gas flow velocity VY becomes the largest.

  The shape of the second inter-chamber passage 62B is such that the main body bottom wall 80 is formed along the width direction GZ in the second reference plane FD, and a part of the third partition wall 72A and the separator cover 9 are high. This is realized based on being formed along the direction GY and being formed so that a part of the third partition wall 72 </ b> A is inclined with respect to the main body bottom wall 80. Specifically, the third partition wall 72A is formed as follows, with the surface facing the separator cover 9 being the partition wall side surface 72AF. That is, the upper partition wall 72AA formed so that the partition wall side surface 72AF is inclined with respect to the main body bottom wall 80 and the separator cover 9 in the second reference plane FD, and the partition wall side surface 72AF extends along the separator cover 9 in the second reference plane FD. The lower partition 72AB is formed as described above. Based on the structure of the third partition wall 72A, the formation mode of the second inter-chamber passage 62B can be expressed as follows. That is, the second inter-chamber passage 62B connects the main body bottom wall 80 and the upper partition wall 72AA on the second reference plane FD and faces the lower partition wall 72AB and the separator cover 9 that face each other, and the upper partition wall 72AA that faces the body bottom wall 80. And the bottom wall 80 of the main body.

<Effect of embodiment>
As described above in detail, according to the oil separator of the engine of the present embodiment, the following effects can be obtained.

  (1) In the oil separator 6 of the present embodiment, the first gas flow velocity VX of the blowby gas is the smallest near the main body bottom wall 80, while the first gas flow velocity VX of the blowby gas is away from the main body bottom wall 80. The first inter-chamber passage 62A is formed so as to be the largest. Accordingly, since the flow of engine oil toward the first opening 7A is suppressed from being blocked by the flow of blow-by gas, the blow-by gas inlet to the separation chamber 61 and the engine oil outlet from the separation chamber 61 are prevented. It is possible to achieve both the common use and the improvement of engine oil discharge efficiency. In addition, since the flow rate of blow-by gas at a position away from the bottom wall 80 of the main body is increased, the effect of gas-liquid separation by the second main body inner wall 72 (sixth partition wall 72D) is enhanced while suppressing a decrease in engine oil discharge efficiency. Will be able to.

  (2) Further, on one cross section in the first inter-chamber passage 62A, improvement in engine oil discharge efficiency by reducing the first gas flow velocity VX and improvement in gas-liquid separation efficiency by increasing the first gas flow velocity VX. Since the improvement is realized, the structure inside the oil separator 6 can be simplified. In addition, productivity can be improved and costs can be reduced. In addition, the oil separator 6 can be reduced in size.

  (3) In the oil separator 6 of the present embodiment, the second gas flow velocity VY of the blowby gas is the smallest near the main body bottom wall 80, while the second gas flow velocity VY of the blowby gas is away from the main body bottom wall 80. The second inter-chamber passage 62B is formed so that becomes the largest. Accordingly, since the flow of engine oil toward the second opening 7B is suppressed from being blocked by the flow of blow-by gas, the blow-by gas inlet to the separation chamber 61 and the engine oil outlet from the separation chamber 61 are suppressed. It is possible to achieve both the common use and the improvement of engine oil discharge efficiency. In addition, since the flow rate of blow-by gas at a position away from the main body bottom wall 80 is increased, the effect of gas-liquid separation by the fourth wall portion 84 can be enhanced while suppressing a decrease in engine oil discharge efficiency. .

  (4) Further, on one cross section in the second inter-chamber passage 62B, improvement in engine oil discharge efficiency by reducing the second gas flow velocity VY and improvement in gas-liquid separation efficiency by increasing the second gas flow velocity VY. Since the improvement is realized, the structure inside the oil separator 6 can be simplified. In addition, productivity can be improved and costs can be reduced. In addition, the oil separator 6 can be reduced in size.

  (5) In the oil separator 6 of the present embodiment, the seventh wall portion 87 is provided at a position facing the first opening 7A in the first separation chamber 61A. As a result, the blow-by gas that has flowed into the first separation chamber 61A via the first opening 7A collides with the seventh wall portion 87 in a state where the flow velocity is high, so that the effect of separating the engine oil from the blow-by gas is enhanced. Will be able to.

  (6) In the oil separator 6 of the present embodiment, the fifth partition wall 72C is provided at a position facing the second opening 7B in the fourth separation chamber 61D. Thereby, since the blow-by gas that has flowed into the fourth separation chamber 61D through the second opening 7B collides with the fifth partition wall 72C with a high flow velocity, the effect of separating the engine oil from the blow-by gas is enhanced. Will be able to.

  (7) In the oil separator 6 of the present embodiment, the first partition 71A is provided as a wall that partitions the first separation chamber 61A and the second separation chamber 61B, and the first partition having the above shape is provided through the first partition 71A. An inter-chamber passage 62A is formed. Thereby, in the oil separator 6 as compared with the case where the element for partitioning the first separation chamber 61A and the second separation chamber 61B and the element for forming the first inter-chamber passage 62A are provided separately. The structure can be simplified.

  (8) In the oil separator 6 of the present embodiment, the third partition 72A is provided as a wall that partitions the fourth separation chamber 61D and the fifth separation chamber 61E, and the second partition of the above shape is provided through the third partition 72A. An inter-chamber passage 62B is formed. Thereby, in the oil separator 6 as compared with the case where the element for partitioning the fourth separation chamber 61D and the fifth separation chamber 61E and the element for forming the second inter-chamber passage 62B are provided separately. The structure can be simplified.

  (9) In the oil separator 6 of this embodiment, the volume of the third separation chamber 61C is set larger than the volumes of the first separation chamber 61A and the second separation chamber 61B. That is, the first separation chamber 61A, the second separation chamber 61B, and the third separation chamber 61C that form a blow-by gas passage between the first opening 7A and the control valve 55 are located on the most downstream side of these chambers. The volume of the third separation chamber 61C located is set to be the largest. As described above, since the chamber volume is set near the control valve 55 where the stagnation of the flow of the blow-by gas is likely to occur compared to the vicinity of the first opening 7A, the effect of the gas-liquid separation associated with the stay of the blow-by gas can be obtained. Can be raised. Further, since the volume of the chamber is set small in the vicinity of the first opening 7A where the momentum of blow-by gas is strong, the effect of gas-liquid separation due to blow-by gas collision with the main body peripheral wall 8 and the second main body inner wall 72 is enhanced. Will be able to. Moreover, since the limited space in the oil separator 6 is effectively used as described above to enhance the gas-liquid separation effect in each separation chamber, the oil separator 6 can be reduced in size. It becomes like this.

  (10) In the oil separator 6 of the present embodiment, the volume of the first separation chamber 61A is set smaller than the volume of the second separation chamber 61B. That is, the first separation chamber 61A, the second separation chamber 61B, and the third separation chamber 61C that form a blow-by gas passage between the first opening 7A and the control valve 55 are arranged on the most upstream side of these chambers. The volume of the first separation chamber 61A located is set to be the smallest. Thus, since the volume of the chamber is set to be the smallest in the vicinity of the first opening 7A where the force of blow-by gas is strong, the effect of gas-liquid separation due to the collision of the blow-by gas with the main body peripheral wall 8 can be further enhanced. It becomes like this.

  (11) In the oil separator 6 of the present embodiment, the volume of the third separation chamber 61C is set larger than the volumes of the fourth separation chamber 61D, the fifth separation chamber 61E, and the sixth separation chamber 61F. That is, for the fourth separation chamber 61D, the fifth separation chamber 61E, the sixth separation chamber 61F, and the third separation chamber 61C that form a blow-by gas passage between the second opening 7B and the control valve 55, these chambers are provided. Among these, the volume of the third separation chamber 61C located on the most downstream side is set to be the largest. As described above, since the chamber volume is set near the control valve 55 where the stagnation of the flow of the blow-by gas is likely to occur compared to the vicinity of the second opening 7B, the effect of gas-liquid separation due to the stay of the blow-by gas can be obtained. Can be raised. Moreover, since the volume of the chamber is set small in the vicinity of the second opening 7B where the force of blow-by gas is strong, the effect of gas-liquid separation due to blow-by gas collision with the second main body inner wall 72 and the main body peripheral wall 8 is enhanced. Will be able to. Moreover, since the limited space in the oil separator 6 is effectively used as described above to enhance the gas-liquid separation effect in each separation chamber, the oil separator 6 can be reduced in size. It becomes like this.

  (12) In the oil separator 6 of the present embodiment, the volume of the fourth separation chamber 61D is set smaller than the volumes of the fifth separation chamber 61E and the sixth separation chamber 61F. That is, for the fourth separation chamber 61D, the fifth separation chamber 61E, the sixth separation chamber 61F, and the third separation chamber 61C that form a blow-by gas passage between the second opening 7B and the control valve 55, these chambers are provided. Among them, the volume of the fourth separation chamber 61D located on the most upstream side is set to be the smallest. Thus, since the volume of the chamber is set to be the smallest in the vicinity of the second opening 7B where the momentum of blow-by gas is strong, the effect of gas-liquid separation due to the collision of the blow-by gas with the inner wall 72 of the second main body is further enhanced. Will be able to.

  (13) In the oil separator 6 of the present embodiment, the first inter-chamber passage 62A is provided as a passage connecting the first separation chamber 61A and the second separation chamber 61B. Thereby, since the effect of improving the gas-liquid separation in the first inter-chamber passage 62A is obtained at a position closer to the first opening 7A, the engine oil flowing into the separation chamber 61 can be separated from the blow-by gas at an early stage. It becomes like this. As a result, the amount of engine oil flowing out of the main body crank chamber 11A can be reduced.

  (14) In the oil separator 6 of the present embodiment, the second inter-chamber passage 62B is provided as a passage connecting the fourth separation chamber 61D and the fifth separation chamber 61E. Thereby, since the effect of improving the gas-liquid separation in the second inter-chamber passage 62B is obtained at a position closer to the second opening 7B, the engine oil flowing into the separation chamber 61 can be separated from the blow-by gas at an early stage. It becomes like this. As a result, the amount of engine oil flowing out of the main body crank chamber 11A can be reduced.

  (15) The oil separator 6 of the present embodiment is provided at a side of the cylinder block 4, that is, at a location closer to the main body crank chamber 11A in the engine 1. Accordingly, the first main body passage 43A and the second main body passage 43B connecting the main body crank chamber 11A and the separation chamber 61 are shortened, so that the engine oil that has flowed out of the main body crank chamber 11A together with the blow-by gas is blown earlier. Can be separated from. As a result, the amount of engine oil flowing out of the main body crank chamber 11A can be reduced.

  (16) The oil separator 6 of the present embodiment is separated from the side of the cylinder block 4, that is, the portion for sending the air in the intake passage 36 into the engine body 11 (the connection portion between the head cover 15 and the second tube 54). It is provided at the position. As a result, the air sent into the head cover 15 from the intake passage 36 flows more reliably into the main body crank chamber 11A, so that the ventilation efficiency of the main body crank chamber 11A can be improved. In other words, air sent into the head cover 15 from the intake passage 36 is suppressed from being returned to the intake passage 36 via the control valve 55 before flowing into the main body crank chamber 11A. Efficiency can be improved. Incidentally, when the oil separator is provided in the head cover 15, the air sent into the head cover 15 from the intake passage 36 is easily returned to the intake passage 36 via the control valve 55 before flowing into the main body crank chamber 11A. Therefore, the ventilation efficiency of the main body crank chamber 11A is lowered.

  (17) An oil separator (basic oil separator) in which the sixth chamber passage 62F is omitted from the oil separator 6 of the present embodiment, that is, a basic oil separator in which the second separation chamber 61B and the fourth separation chamber 61D are not connected. Based on the comparison with the oil separator 6 of the present embodiment, effects obtained by the oil separator 6 will be described. Hereinafter, a state in which the flow velocity of the blow-by gas flowing into the separation chamber 61 exceeds the standard magnitude is referred to as a low negative pressure state.

  As shown in FIG. 19, in the basic oil separator, it has been confirmed that a large amount of engine oil stays on the main body bottom wall 80 when the low negative pressure state is continued. On the other hand, in the oil separator 6 of the present embodiment, even when the low negative pressure state is continued, the engine oil on the main body bottom wall 80 passes through the sixth chamber passage 62F to the second opening 7B. It has been confirmed that it flows. Thus, according to the oil separator 6 of the present embodiment, it is possible to suitably suppress the reduction in engine oil discharge efficiency when the low negative pressure state is continued. The reason why the engine oil flows into the second opening 7B via the sixth inter-chamber passage 62F as described above is considered as follows. That is, when the low negative pressure state is continued, the volume of the engine oil becomes higher from the first opening 7A toward the sixth partition wall 72D on the main body bottom wall 80, and at a position adjacent to the sixth partition wall 72D. It has been confirmed that the volume of engine oil is the highest. For this reason, in the vicinity of the sixth partition wall 72D, the force that causes the engine oil to move on the main body bottom wall 80 due to its own weight is greater than that in the vicinity of the first opening 7A, so that the engine oil is in the second separation chamber. It is considered that the air flows from 61B to the sixth inter-chamber passage 62F.

  (18) In the oil separator 6 of the present embodiment, the separator body 7 is provided on the side portion of the cylinder block 4. As a result, the separator body 7 is also integrally formed when the cylinder block 4 is molded, so that productivity can be improved.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.
The oil separator 6 of the present embodiment is configured as an oil separator 6 in which the shape of the first inter-chamber passage 62A of the first embodiment is changed as described below. Note that the oil separator 6 of the present embodiment has substantially the same structure as the oil separator 6 of the first embodiment except for the points described below. In the drawings, elements common to the first embodiment are denoted by the same reference numerals as in the first embodiment.

  As shown in FIG. 20, the first inter-chamber passage 62A has a lower passage 62AA provided in the vicinity of the main body bottom wall 80 in the first passage cross section FA and a position away from the main body bottom wall 80 in the first passage cross section FA. The upper passage 62AB is provided. Further, the area of the lower passage 62AA in the first passage section FA is formed to be larger than the area of the upper passage 62AB in the first passage section FA. Thereby, regarding the distribution of the first gas flow velocity VX in the first passage cross section FA, the first gas flow velocity VX is the smallest in the vicinity of the main body bottom wall 80, while the first gas flow velocity VX is at a position away from the main body bottom wall 80. VX is the largest. The shape of the first inter-chamber passage 62A can also be applied to the second inter-chamber passage 62B.

<Effect of embodiment>
As described above in detail, according to the oil separator of the engine of the present embodiment, operational effects according to the operational effects (1) to (17) of the first embodiment can be obtained.

(Third embodiment)
A third embodiment of the present invention will be described with reference to FIG.
The oil separator 6 of the present embodiment is configured as an oil separator 6 in which the shape of the first inter-chamber passage 62A of the first embodiment is changed as described below. Note that the oil separator 6 of the present embodiment has substantially the same structure as the oil separator 6 of the first embodiment except for the points described below. In the drawings, elements common to the first embodiment are denoted by the same reference numerals as in the first embodiment.

  As shown in FIG. 21, the first inter-chamber passage 62A is formed by a lower passage 62AC provided between the main body bottom wall 80 and the first partition wall 71A, and an upper passage 62AD provided in the first partition wall 71A. Yes. Further, the area of the lower passage 62AC in the first passage section FA is formed to be larger than the area of the upper passage 62AD in the first passage section FA. As a result, regarding the distribution of the first gas flow velocity VX in the first passage section FA, the first gas flow velocity VX is the smallest in the lower passage 62AC adjacent to the main body bottom wall 80, while the upper passage separated from the main body bottom wall 80. At 62AD, the first gas flow velocity VX is the largest. The shape of the first inter-chamber passage 62A can also be applied to the second inter-chamber passage 62B.

<Effect of embodiment>
As described above in detail, according to the oil separator of the engine of the present embodiment, operational effects according to the operational effects (1) to (17) of the first embodiment can be obtained.

(Other embodiments)
Each said embodiment can also be changed and implemented as shown below, for example.
In each of the above embodiments, the oil separator 6 has a structure in which two openings, that is, the first opening 7A and the second opening 7B are provided as blow-by gas inlets. However, the first opening 7A and the second opening are employed. One of the parts 7B can be omitted.

  In each of the above embodiments, the first main body passage 43A is formed as a passage connecting the crank chamber 12A of the crankcase 12 and the first opening 7A of the main body peripheral wall 8, but the crank chamber 42 and the main body peripheral wall 8 of the cylinder block 4 are formed. The first main body passage 43A can also be formed as a passage connecting the first opening 7A.

  In each of the above embodiments, the second main body passage 43B is formed as a passage connecting the crank chamber 12A of the crankcase 12 and the second opening 7B of the main body peripheral wall 8, but the crank chamber 42 and the main body peripheral wall 8 of the cylinder block 4 are formed. The second main body passage 43B can also be formed as a passage connecting the second opening 7B.

  In each of the above embodiments, a structure in which the separator body 7 is formed integrally with the cylinder block 4 is adopted, but the entire oil separator 6 can be formed separately from the cylinder block 4.

  In each of the above embodiments, the structure in which the first partition 71A is formed integrally with the cylinder block 4 is employed. However, the first partition 71A is formed separately from the cylinder block 4 and formed integrally with the separator cover 9. You can also Further, the first partition wall 71 </ b> A can be formed separately from the cylinder block 4 and the separator cover 9.

  In each of the above embodiments, the structure in which the third partition wall 72A is formed integrally with the cylinder block 4 is adopted. However, the third partition wall 72A is formed separately from the cylinder block 4 and formed integrally with the separator cover 9. You can also Further, the third partition wall 72 </ b> A can be formed exceptionally from the cylinder block 4 and the separator cover 9.

  In each of the above embodiments, the configuration in which the oil separator 6 is provided on the side portion of the cylinder block 4 is adopted. However, the location where the oil separator 6 is provided can be changed to the side portion of the crankcase 12. Further, the location where the oil separator 6 is provided is not limited to the illustrated location and can be changed as appropriate.

  -The shape of 62 A of 1st chamber passages is not restricted to the shape illustrated in said each embodiment, It can change suitably. In short, the distribution of the first gas flow velocity VX in the first passage section FA is such that the first gas flow velocity VX in the vicinity of the main body bottom wall 80 is smaller than the first gas flow velocity VX at a position away from the main body bottom wall 80. If there is, an appropriate shape can be adopted as the shape of the first inter-chamber passage 62A.

  -The shape of the 2nd chamber passage 62B is not restricted to the shape illustrated in said each embodiment, It can change suitably. In short, the distribution of the second gas flow velocity VY in the second passage section FC is such that the second gas flow velocity VY in the vicinity of the main body bottom wall 80 is smaller than the second gas flow velocity VY at a position away from the main body bottom wall 80. If there is, an appropriate shape can be adopted as the shape of the second inter-chamber passage 62B.

(Other technical ideas)
Other technical ideas related to the present invention will be described below.
(1) A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from the blowby gas through contact between the blowby gas and the separation wall in a process in which the blowby gas flows from the gas inlet to the gas outlet, the outlet of the blowby gas from the chamber being a gas outlet; Of the engine, the passage connecting the crank chamber and the gas inlet is defined as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. In the oil separator, the chamber in which the gas inlet is provided in the gas chamber is a first gas chamber, A chamber in which the separation wall is provided is a second gas chamber, a portion that partitions the first gas chamber and the second gas chamber is a partition, and oil separated through the separation wall flows toward the gas inlet. A portion connecting at the time is defined as a bottom wall, and a passage formed between the bottom wall and the partition wall and connecting the first gas chamber and the second gas chamber is defined as an indoor passage. The direction along the bottom wall is defined as the width direction, the direction perpendicular to the width direction in the longitudinal section of the indoor passage is defined as the height direction, and the width of the indoor passage in the longitudinal section of the indoor passage is defined as the passage width. An oil separator for an engine, wherein the passage width is set to be the largest in the vicinity of, while the passage width is set to the smallest at a position away from the bottom wall in the height direction.

  According to the above technical idea, the flow rate of blow-by gas in the vicinity of the bottom wall is reduced, so that the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. Moreover, since the flow velocity of the blow-by gas at a position away from the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

  (2) A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from the blowby gas through contact between the blowby gas and the separation wall in a process in which the blowby gas flows from the gas inlet to the gas outlet, the outlet of the blowby gas from the chamber being a gas outlet; Of the engine, the passage connecting the crank chamber and the gas inlet is defined as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. In the oil separator, the chamber in which the gas inlet is provided in the gas chamber is a first gas chamber, A chamber in which the separation wall is provided is a second gas chamber, a portion that partitions the first gas chamber and the second gas chamber is a partition, and oil separated through the separation wall flows toward the gas inlet. A plane including a vertical cross section of the partition wall, wherein a portion connecting the bottom wall is a bottom wall, a passage formed between the partition wall and the bottom wall and connecting the first gas chamber and the second gas chamber is an indoor passage. Is defined as a reference plane, and the indoor passage provided at a position adjacent to the bottom wall in the reference plane is defined as a first indoor passage, and is provided at a position farther from the bottom wall than the first indoor passage in the reference plane. The indoor passage is a second indoor passage, the area of the first indoor passage in the reference plane is a first passage area, and the area of the second indoor passage in the reference plane is a second passage area, the first passage. The area is the second Oil separator of the engine, characterized in that it is set larger than the road area.

  According to the above technical idea, the flow rate of blow-by gas in the first indoor passage, that is, near the bottom wall is reduced, so that the flow of oil toward the gas inlet is prevented from being hindered by the flow of blow-by gas. become. Accordingly, it is possible to achieve both the common use of the blow-by gas inlet to the gas chamber and the oil outlet from the gas chamber and the improvement of the oil discharge efficiency. In addition, since the flow rate of blow-by gas at a position away from the second indoor passage, that is, the bottom wall is increased, the oil separation effect by the separation wall can be enhanced while suppressing a decrease in oil discharge efficiency.

The schematic diagram which shows typically the structure inside the engine to which the oil separator was applied about 1st Embodiment which actualized the oil separator of the engine of this invention. The schematic diagram which shows typically the internal structure corresponded in the cross-section along a length direction about the engine of the embodiment. The schematic diagram which shows typically the internal structure equivalent to the surface structure along the width direction about the engine of the embodiment. FIG. 4 is a schematic diagram in which the flow at the time of low load of the engine is added to the internal structure corresponding to the cross-sectional structure along the width direction of the engine with respect to the gas flow in the engine blow-by gas reduction device of the embodiment. FIG. 4 is a schematic diagram in which the flow at the time of high engine load is added to the internal structure corresponding to the cross-sectional structure along the width direction of the engine with respect to the gas flow in the engine blow-by gas reduction device of the same embodiment. The perspective view which shows the perspective structure of the state in which the separator cover of the oil separator was attached about the cylinder block which comprises the engine of the embodiment. The perspective view which shows the perspective structure of the state which removed the separator cover of the oil separator about the cylinder block which comprises the engine of the embodiment. The front view which shows the front structure seen from the VA direction of FIG. 6 about the cylinder block which comprises the engine of the embodiment. The front view which shows the front structure seen from the VA direction of FIG. 7 about the cylinder block which comprises the engine of the embodiment. Sectional drawing which shows the cross-sectional structure which follows the DA-DA line of FIG.8 and FIG.9 about the cylinder block which comprises the engine of the embodiment. Sectional drawing which shows the cross-sectional structure which follows the DB-DB line | wire of FIG.8 and FIG.9 about the cylinder block which comprises the engine of the embodiment. The front view which shows the front structure seen from the VA direction of FIG. 6 about the oil separator of the engine of the embodiment. The front view which shows the front structure seen from the VA direction of FIG. 7 about the oil separator of the engine of the embodiment. The perspective view which shows the perspective structure of the state which removed the separator cover about the oil separator of the engine of the embodiment. The front view which added about the oil separator of the engine of the embodiment with respect to the front structure which looked at the boundary of the chamber formed inside, and the channel | path from the VA direction of FIG. Regarding the flow of blow-by gas and engine oil in the engine oil separator of the same embodiment, the flow when the flow rate of blow-by gas is maintained at a standard size or smaller is shown in the VA direction of FIG. The front view added with respect to the front structure of the oil separator seen from. Sectional drawing which shows the cross-sectional structure which follows the DC-DC line | wire of FIG.12 and FIG.13 about the oil separator of the engine of the embodiment. Sectional drawing which shows the cross-sectional structure which follows the DD-DD line of FIG.12 and FIG.13 about the oil separator of the engine of the embodiment. Regarding the flow of blow-by gas and engine oil in the engine oil separator of the same embodiment, the flow of the oil separator as viewed from the VA direction of FIG. The front view added with respect to the front structure. Sectional drawing which shows the cross-sectional structure equivalent to the cross-sectional structure which followed the DC-DC line of FIG.12 and FIG.13 in the oil separator about 2nd Embodiment which actualized the oil separator of the engine of this invention. Sectional drawing which shows the cross-section corresponding to the cross-section along the DC-DC line of FIG.12 and FIG.13 in the oil separator about 3rd Embodiment which actualized the oil separator of the engine of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 11 ... Engine main body, 11A ... Main body crank chamber, 12 ... Crank case, 12A ... Crank chamber, 13 ... Oil pan, 14 ... Cylinder head, 14A ... Intake port, 14B ... Exhaust port, 15 ... Head cover, 15A ... Cover passage, 16 ... Chain cover, 16A ... Cover passage, 21 ... Crankshaft, 22 ... Timing chain, 23 ... Piston, 24 ... Connecting rod, 25 ... Intake valve, 26 ... Exhaust valve, 27 ... Intake camshaft 28 ... Exhaust camshaft, 29 ... Injector, 3 ... Intake device, 31 ... Air intake, 32 ... Air cleaner, 32A ... Air element, 33 ... Intake hose, 34 ... Throttle body, 34A ... Throttle valve, 35 ... Intake manifold, 35A ... Surge tank, 35B ... Sub pipe, 36 ... Intake passage, 36A ... First intake passage, 36B ... Second intake passage, 36C ... Third intake passage, 4 ... Cylinder block, 4A ... Upper block, 4B ... lower block, 41 ... cylinder, 41A ... first cylinder, 41B ... second cylinder, 41C ... third cylinder, 41D ... fourth cylinder, 41R ... combustion chamber, 42 ... crank chamber, 42A ... first crank chamber, 42B ... 2nd crank chamber, 42C ... 3rd crank chamber, 42D ... 4th crank chamber, 43 ... Body passage, 43A ... 1st body passage, 43B ... 2nd body passage, 44 ... Flange, 44A ... 1st flange, 44B ... 2nd flange, 44C ... 3rd flange, 44D ... 4th flange, 45 ... Horizontal rib, 45A ... 1st horizontal rib, 45B ... 2nd horizontal rib, 45 ... 3rd horizontal rib, 45D ... 4th horizontal rib, 46 ... vertical rib, 46A ... 1st vertical rib, 46B ... 2nd vertical rib, 46C ... 3rd vertical rib, 46D ... 4th vertical rib, 47 ... vertical rib 47A ... 5th vertical rib, 47B ... 6th vertical rib, 47C ... 7th vertical rib, 5 ... Blow-by gas reducing device, 51 ... One-way passage, 52 ... Two-way passage, 53 ... First tube, 53A ... In-pipe Passage 54, second tube 54A ... In-pipe passage 55 ... Control valve 6 ... Oil separator 61 ... Separation chamber 61A ... First separation chamber 61B ... Second separation chamber 61C ... Third separation chamber 61D ... 4th separation chamber, 61E ... 5th separation chamber, 61F ... 6th separation chamber, 62 ... Inter-chamber passage, 62A ... 1st inter-chamber passage, 62AA ... Lower passage, 62AB ... Upper passage, 62AC ... Lower passage, 62AD ... Upper passage, 62B ... Second passage between chambers, 6 2C ... 3rd chamber passage, 62D ... 4th chamber passage, 62E ... 5th chamber passage, 62F ... 6th chamber passage, 63 ... Bolt, 7 ... Separator body, 7A ... 1st opening part, 7B ... 2nd opening, 71 ... 1st main body inner wall, 71A ... 1st partition, 71AA ... Upper partition, 71AB ... Lower partition, 71AF ... Partition wall side, 71B ... 2nd partition, 72 ... 2nd body inner wall, 72A ... 3rd Partition wall, 72AA ... Upper partition wall, 72AB ... Lower partition wall, 72AF ... Partition wall side surface, 72B ... Fourth partition wall, 72C ... Fifth partition wall, 72D ... Sixth partition wall, 73 ... Main body side wall, 74 ... Boss, 74A ... First boss, 74B ... 2nd boss, 74C ... 3rd boss, 74D ... 4th boss, 74E ... 5th boss, 74F ... 6th boss, 74G ... 7th boss, 74H ... 8th boss, 75 ... Bolt hole, 8 ... Body A peripheral wall, 8A ... 1st main body peripheral wall, 8B ... 2nd main body peripheral wall, C ... 3rd main body peripheral wall, 8D ... 4th main body peripheral wall, 80 ... Main body bottom wall, 81 ... 1st wall part, 82 ... 2nd wall part, 83 ... 3rd wall part, 84 ... 4th wall part, 85 ... 5th wall part, 86 ... 6th wall part, 87 ... 7th wall part, 88 ... 8th wall part, 9 ... Separator cover, 91 ... Valve mounting seat, 92 ... Bolt hole.

Claims (13)

A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A chamber in the gas chamber in which the gas inlet is provided is a first gas chamber, a chamber in the gas chamber in which the separation wall is provided is a second gas chamber, and the first gas chamber and the second gas chamber are partitioned. A partition wall, a portion connected when oil separated through the separation wall flows toward the gas inlet as a bottom wall, and a passage connecting the first gas chamber and the second gas chamber as an indoor passage. The flow velocity of blowby gas in the indoor passage is defined as the gas flow velocity, and the distribution of the gas flow velocity in the longitudinal section of the indoor passage is at a position away from the bottom wall while the gas flow velocity is the smallest in the vicinity of the bottom wall. The engine oil separator is characterized in that the indoor passage is formed so as to maximize the gas flow velocity. A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A chamber in the gas chamber in which the gas inlet is provided is a first gas chamber, a chamber in the gas chamber in which the separation wall is provided is a second gas chamber, and oil separated through the separation wall is directed to the gas inlet. The bottom wall is a portion that reaches the bottom wall, and a space in which oil flows from the second gas chamber to the first gas chamber is formed at a position adjacent to the bottom wall and the second gas chamber to the second gas chamber. A passage including a space in which a flow of blow-by gas toward the gas chamber is formed is a first indoor passage, and the second gas chamber is moved from the first gas chamber at a position farther from the bottom wall than the first indoor passage. A passage in which a flow of blow-by gas toward the second indoor passage is formed, and a plane including a longitudinal section of the first indoor passage and a longitudinal section of the second indoor passage is defined as a reference plane. Oil separator of the engine, wherein the area of the interior passage is set larger than the area of the second chamber passage. A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A chamber in the gas chamber in which the gas inlet is provided is a first gas chamber, a chamber in the gas chamber in which the separation wall is provided is a second gas chamber, and oil separated through the separation wall is directed to the gas inlet. The bottom wall is a portion that connects to the first gas chamber and the second gas chamber is an indoor passage, and the width of the indoor passage in the longitudinal section of the indoor passage is the passage width. An engine oil separator characterized in that the passage width near the wall is set larger than the passage width at other positions. In the oil separator of the engine according to claims 1-3,
Engine oil characterized in that two sets of separation structures are provided by using a structure including the gas inlet, the first gas chamber, the separation wall, and the second gas chamber as a separation structure. Separator. The engine oil separator according to claim 4,
For the two sets of separation structures, one separation structure is a first separation structure, the other separation structure is a second separation structure, and the separation wall of the first separation structure is separated between structures. The second gas chamber of the first separation structure and the first gas chamber of the second separation structure are provided as walls at positions adjacent to each other through the inter-structure separation wall; An inter-structure passage connecting the second gas chamber of the one separated structure and the first gas chamber of the second structure is formed through the inter-structure separation wall; and The engine oil separator, wherein the separated oil flows into the first gas chamber of the second structure through the inter-structure passage. In the oil separator of the engine according to any one of claims 1 to 5,
An engine oil separator, wherein the volume of the first gas chamber is set smaller than the volume of the second gas chamber. The engine oil separator according to any one of claims 1 to 6,
A chamber in which the gas outlet is provided in the gas chamber is a third gas chamber, and blow-by gas moves through the gas chamber in the order of the first gas chamber, the second gas chamber, and the third gas chamber. Engine oil separator. The engine oil separator according to claim 7,
An engine oil separator, wherein a volume of the third gas chamber is set larger than volumes of the first gas chamber and the second gas chamber. A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A portion that is connected when oil separated through the separation wall flows toward the gas inlet is a first portion, a passage including a space adjacent to the bottom wall is an indoor passage, A direction along the first portion is a width direction, a direction perpendicular to the width direction in the longitudinal section of the indoor passage is a height direction, and a portion facing the first portion in the height direction is a second direction. A portion connecting the first portion and the second portion and facing each other as a third portion and a fourth portion, respectively, and the width of the indoor passage in the longitudinal section of the indoor passage is the passage width. And forming the indoor passage surrounded by the first part, the second part, the third part, and the fourth part, and the second part and the third part. At least one of the part and the fourth part The passage is formed so as to be inclined with respect to the first part, the passage width is set to be smaller as the distance from the first part is increased in the height direction, and the oil separator An oil separator for an engine, characterized in that is provided on a cylinder block or a crankcase. A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A portion where the oil separated through the separation wall flows toward the gas inlet is defined as a bottom wall, a passage including a space adjacent to the bottom wall is defined as an indoor passage, and a flow rate of blow-by gas in the indoor passage is defined as a gas flow rate. As the flow velocity, the indoor passage is formed such that the gas flow velocity in the vicinity of the bottom wall is smaller than the gas flow velocity at other positions with respect to the distribution of the gas flow velocity in the longitudinal section of the indoor passage. Engine oil separator. A passage connecting the intake passage and the crank chamber is used as a reduction passage, a gas chamber functioning as a part of the reduction passage is provided, and a blow-by gas inlet to the gas chamber is used as a gas inlet. Oil is separated from blow-by gas through contact between the blow-by gas and the separation wall in a process in which the blow-by gas flows from the gas inlet to the gas outlet, with the blow-by gas outlet serving as a gas outlet; An engine oil separator configured such that a passage connecting a chamber and the gas inlet serves as an inlet-side passage, and the separated oil flows into the crank chamber through the gas inlet and the inlet-side passage. ,
A portion where the oil separated through the separation wall flows when flowing toward the gas inlet is defined as a bottom wall, and a passage including a space adjacent to the bottom wall is defined as a first indoor passage, which is more than the first indoor passage. The indoor passage provided at a position away from the bottom wall is defined as a second indoor passage, and a plane including a longitudinal section of the first indoor passage and the second indoor passage is defined as a reference plane. Is set to be larger than the area of the second indoor passage. The oil separator for an engine according to any one of claims 1 to 11,
An engine oil separator, characterized in that an inlet side separation wall for separating oil from blow-by gas is provided at a position facing the gas inlet.   An engine provided with the oil separator according to any one of claims 1 to 12.

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