JP6001407B2 - Oil separator - Google Patents

Description

  The present invention relates to an oil separator, and more particularly to an oil separator applied to a blow-by gas reduction device for an engine.

  In an automobile engine, blow-by gas flowing out into a crankcase is not released into the atmosphere but returned to the intake system of the engine and burned again (blow-by gas reduction device). In such a blow-by gas reduction device, it is necessary to remove mist contained in the blow-by gas in advance, an oil separator is interposed in the blow-by gas recirculation system, and the gas outlet of the oil separator is connected to the intake pipe of the engine. The blow-by gas is guided to the oil separator using the negative pressure generated in communication.

  By the way, the negative pressure in the intake passage of the intake pipe fluctuates in accordance with the operating condition of the engine, and when the pressure in the intake passage becomes higher than the pressure of the oil separator, there is a possibility of backflow. A backflow prevention means (PCV valve) is interposed in the system (for example, see Patent Document 1).

Japanese Patent No. 4594254

  An object of this invention is to provide the oil separator which can implement | achieve an inexpensive blow-by gas reduction apparatus, without installing the backflow prevention means comprised independently.

In order to achieve the above-mentioned object, the oil separator according to claim 1 has a separator plate disposed so as to move against blow-by gas passing through the gas passage, and urges the separator plate to provide the gas passage. An oil separator having a check valve function in contact therewith, wherein the gas passage is formed by a cylindrical body, the separator plate is used as a ceiling wall, and a gas ejection hole is provided in a peripheral wall. The cylindrical cap is fitted and slidably contacted with the upper opening peripheral wall of the cylindrical body .

According to a second aspect of the present invention, there is provided the oil separator according to the first aspect of the present invention, wherein a plurality of single separators in which the cap is brought into contact with the gas outlet of the cylindrical body with the same urging force are connected in series. It is characterized by.

Furthermore, an oil separator according to a third aspect is the invention according to the first or second aspect , wherein a plurality of gas passages are formed and separator plates are respectively applied to gas outlets of the gas passages by different urging forces. Characterized by contact.

The oil separator according to claim 4 is characterized in that, in the invention according to claim 3 , the biasing force is made different by changing the thickness of the separator plate.

The oil separator according to claim 5 is characterized in that, in the invention according to claim 3 , the biasing force is made different by making the opening area of the gas outlet of the gas passage different.

According to a sixth aspect of the present invention, in the invention of the third aspect , the urging force is made different by pressing the separator plate with a spring having a different urging force.

According to the oil separator of the first aspect of the present invention, since the check valve is constituted by the separator plate of the oil separator, no special backflow prevention means is required, and therefore an inexpensive blow-by gas reduction device is provided. can do.
In the oil separator according to the first aspect of the present invention, the cap provided with the separator plate slides along the peripheral wall of the cylinder, so that the blow-by gas flowing through the gas passage of the cylinder is separated by the separator plate. It is always kept in a position that opposes the flow, so that a high oil mist separation efficiency is obtained.

Further, according to the oil separator of the second aspect of the present invention, the blow-by gas is separated through the plurality of separator plates, so that higher oil mist separation efficiency can be obtained.

Furthermore, according to the oil separator of the present invention of claim 3 , the blow-by gas flow rate in the gas passage can be changed in response to fluctuations in the negative pressure in the intake pipe, so that it is ejected from the gas outlet in the gas passage. The gas flow rate can be maintained substantially constant, and a stable and high oil mist separation efficiency can be obtained.

In the oil separator according to the fourth aspect of the present invention, the separator plate is urged to the gas outlet of the gas passage by its own weight, and the magnitude of the urging force is set by the plate thickness of the separator plate. So no special biasing means are required and therefore cheaper.

Further, according to the oil separator according to the present invention of claim 5 described above, the operation start timing of the separator plate is shifted by changing the area of the gas outlet of the gas passage, so that no special mechanism or the like is required. Therefore, it becomes cheaper.

Further, according to the oil separator of the present invention described in claim 6 , since the spring is pressed by the spring, the separator plate can be stably urged to the gas outlet of the gas passage by different urging forces, and the operation can be performed. Stabilize.

1 is a cross-sectional view conceptually showing a first embodiment of an oil separator according to the present invention. It is the partial expanded sectional perspective view which showed the cylinder and cap of the oil separator of 1st Embodiment. It is explanatory drawing which showed operation | movement of the oil separator of 1st Embodiment. It is sectional drawing which showed notionally 2nd Embodiment of the oil separator which concerns on this invention. It is the partial expanded sectional perspective view which showed the cylinder and cap of the oil separator of 2nd Embodiment. It is explanatory drawing which showed operation | movement of the oil separator of 2nd Embodiment. It is sectional drawing which showed notionally 3rd Embodiment of the oil separator which concerns on this invention. It is sectional drawing which showed notionally 4th Embodiment of the oil separator which concerns on this invention. It is the partial expanded sectional perspective view which showed the modification of the cap in the oil separator which concerns on this invention. It is a conceptual principal part sectional drawing which showed the example which applied this invention to the cyclone type oil separator. It is the principal part perspective view which showed notionally 5th Embodiment of the oil separator which concerns on this invention.

  Hereinafter, an oil separator according to the present invention will be described based on embodiments shown in the drawings.

  FIG. 1 shows a cylinder head 1 and a cylinder head cover 2 of an engine. In this engine, an oil separator 10 is disposed in the cylinder head cover 2.

  In the oil separator 10, the inside of the cylinder head cover 2 is divided into a separator chamber 12 and a camshaft chamber 13 by a partition wall 11. The separator chamber 12 is a sealed space, and a gas outflow port 14 is formed at the upper end. In this engine, the separator chamber 12 is communicated with an intake passage (not shown) via the gas outflow port 14.

In the partition wall 11, a plurality of cylinders (four in the embodiment shown in FIG. 1) 15 defining the gas passage 15 a are erected. The cylinder 15 is installed such that its axis is oriented substantially in the vertical direction. As shown in FIG. 2, a cap 16 is put on the upper end of the cylinder 15 so as to close the gas outlet 15 b at the upper end opening of the gas passage 15 a.
In the oil separator 10 of this embodiment, as shown in FIG. 1, the oil scattering prevention plate 17 is installed below the gas inlet 15 c of the cylinder 15, and the oil scattered by the rotation of the cam 3 is the cylinder. 15 is prevented from being scattered.

  The cap 16 is formed by a cylindrical peripheral wall 16a and a ceiling wall 16b that closes an upper opening of the cylindrical peripheral wall. The ceiling wall 16b has a function as a separator plate described later. In this embodiment, the plate thicknesses L1 to L4 (L1 <L2 <L3 <L4) of the ceiling wall 16b of the four caps 16 are different. Further, several slits 16c are formed in the cylindrical peripheral wall 16a of the cap 16 in the vertical direction (direction parallel to the axis). The cap 16 is fitted so that the inner surface of the cylindrical peripheral wall 16 a is in sliding contact with the outer surface of the peripheral wall of the cylindrical body 15 of the partition wall 11.

  Therefore, the cap 16 is positioned so that the ceiling wall 16 b opposes the flow of blow-by gas passing through the cylinder 15. And the ceiling wall 16b is maintained in the state contact | abutted to the gas jet nozzle 15b of the cylinder 15 with the urging | biasing force by dead weight.

In the oil separator 10 configured as described above, the differential pressure is small as shown in FIG. 3A according to the differential pressure between the pressure corresponding to the negative pressure generated in the intake passage and the pressure in the camshaft chamber 13. In this case, the cap 16 having the thin ceiling wall 16b, that is, the light cap 16 is separated upward from the upper opening end of the cylindrical body 15, and as the differential pressure increases, FIG. As shown in FIG. 3, the thick ceiling wall 16b having the plate thickness L is opened, and further, the thicker ceiling wall 16b having the plate thickness L is sequentially opened as shown in FIG.
That is, as the negative pressure in the intake pipe increases, the opening area of the gas passage 15a increases correspondingly. Thereby, the flow velocity of the gas ejected from the gas ejection port 15b of the gas passage can be maintained substantially constant.

  Therefore, the blow-by gas in the camshaft chamber 13 is sucked from the lower end of the cylindrical body 15 and is ejected to the separator chamber 12 through the slit 16 c of the cap 16. At that time, the blow-by gas collides with the separator surface of the ceiling wall (separator plate) 16b of the cap 16, where the mist in the blow-by gas is separated. The blowby gas from which the mist has been separated and removed in this manner is guided to the separator chamber 12 through the slit 16c, and is returned from the gas outlet port 14 to an intake pipe (not shown). On the other hand, the separated mist falls through the gas passage 15 a and is returned to the camshaft chamber 13.

  When the pressure in the intake passage becomes higher than the pressure in the camshaft chamber 13, air flows backward from the intake passage toward the oil separator. According to the oil separator 10 according to the present invention, however, Since the ceiling wall 16b of the cap 16 closes the gas outlet 15b of the cylindrical body 15, there is no possibility that air flows backward.

  By the way, since the negative pressure in the intake passage varies depending on the operating condition of the engine, the flow rate of gas in the oil separator 10 changes. For example, when the flow rate of blow-by gas decreases, the separation efficiency of mist increases. May decrease. Further, if the passage area is reduced in order to increase the gas flow rate, the flow resistance becomes high and the blow-by gas cannot be sufficiently supplied during high-speed rotation of the engine.

  In the oil separator 10 according to this embodiment, the flow rate of the blow-by gas is substantially constant without changing as described above, so that sufficient mist removal can always be ensured.

4 to 6 show a second embodiment of the oil separator according to the present invention.
In the oil separator 20 of this embodiment, the inside of the cylinder head cover 2 is divided into a separator chamber 22 and a camshaft chamber 23 by a partition wall 21 as in the oil separator 10 of the above embodiment. The separator chamber 22 is a sealed space, and a gas outflow port 24 is formed at the upper end. In this engine, the separator chamber 22 is communicated with an intake passage (not shown) via a gas outflow port 24.

The partition wall 21 is provided with a plurality of cylinders 25 (four in the embodiment shown in FIG. 4) that define gas passages 25a. The cylindrical body 25 is installed such that its axis is oriented substantially in the vertical direction. Further, as shown in FIG. 5, the opening area (diameter D) of the gas outlet 25 b is narrowed inward at the upper end of the cylindrical body 25. In this embodiment, as shown in FIG. 4, the opening areas (diameter D1>D2>D3> D4) of the gas ejection ports 25b in the four cylinders 25 are different.
Also in the oil separator 20 of this embodiment, the oil scattering prevention plate 27 is installed below the gas inlet 25c of the cylinder 25, and the oil scattered by the rotation of the cam 3 is scattered to the cylinder 25. Is preventing.

  And the cap 26 is covered so that the gas outlet 25b of the upper end opening of the gas passage 25a may be plugged up. The cap 26 is formed by a cylindrical peripheral wall 26a and a ceiling wall 26b that closes an upper opening of the cylindrical peripheral wall. The ceiling wall 26b functions as a separator plate described later. Further, several slits 26c are formed in the cylindrical peripheral wall 26a of the cap 26 in the vertical direction (direction parallel to the axis). The cap 26 is fitted so that the inner surface of the cylindrical peripheral wall 26 a is in sliding contact with the outer surface of the peripheral wall of the cylindrical body 25 of the partition wall 21.

  Therefore, the cap 26 is positioned so that the ceiling wall 26 b opposes the flow of blow-by gas passing through the cylindrical body 25. And the ceiling wall 26b is maintained in the state which contact | abutted to the gas outlet 25b of the cylinder 25 by the urging | biasing force by dead weight.

In the oil separator 20 configured as described above, the differential pressure is small as shown in FIG. 6A according to the differential pressure between the pressure corresponding to the negative pressure generated in the intake passage and the pressure in the camshaft chamber 23. In this case, as shown in FIG. 6 (b), the cap 26 that comes into contact with the upper end opening having a large opening area D is separated upward from the upper opening end of the cylindrical body 25, and the differential pressure increases as shown in FIG. The ceiling wall 26b of the cap 26 is sequentially opened as shown in FIG. 6C.
That is, as the negative pressure in the intake pipe increases, the opening area of the gas passage 25a increases correspondingly. Thereby, the flow velocity of the gas ejected from the gas ejection port 25b of the gas passage can be maintained substantially constant.

  Therefore, the blow-by gas in the camshaft chamber 23 is sucked from the gas inlet 25 c of the cylindrical body 25 and is ejected to the separator chamber 22 through the slit 26 c of the cap 26. At that time, the blow-by gas collides with the separator surface of the ceiling wall (separator plate) 26b of the cap 26, and the mist in the blow-by gas is separated. The blowby gas from which the mist has been separated and removed in this manner is guided to the separator chamber 22 through the slit 26c, and is returned to the intake pipe (not shown) from the gas outflow port 24. On the other hand, the separated mist falls through the gas passage 25 a and is returned to the camshaft chamber 23.

  When the pressure in the intake passage becomes higher than the pressure in the camshaft chamber 23, air flows backward from the intake passage toward the oil separator. According to the oil separator 20 of the present invention, however, Since the ceiling wall 26b of the cap 26 closes the gas outlet 25b of the cylindrical body 25, there is no possibility that air flows backward. Moreover, in the oil separator 20 of this embodiment, since the flow rate of blow-by gas is substantially constant without changing as described above, sufficient mist removal can always be ensured.

FIG. 7 shows a third embodiment of the oil separator according to the present invention.
In the oil separator 30, the inside of the cylinder head cover 2 is divided into a separator chamber 32 and a camshaft chamber 33 by a partition wall 31. The separator chamber 32 is a sealed space, and a gas outflow port 34 is formed at the upper end. In this engine, the separator chamber 32 is communicated with an intake passage (not shown) via a gas outflow port 34.

A plurality of cylinders (three in the embodiment shown in FIG. 7) 35 that define the gas passage 35 a are erected on the partition wall 31. The cylindrical body 35 is installed such that its axis is oriented substantially in the vertical direction. A cap 36 is put on the upper end of the cylindrical body 35 so as to close the gas ejection port 35b at the upper end opening of the gas passage 35a.
In the oil separator 30 of this embodiment as well, an oil splatter prevention plate 37 is installed below the gas inlet 35c of the cylinder 35 so that the oil scattered by the rotation of the cam is scattered to the cylinder 35. It is preventing.

  The cap 36 is formed by a cylindrical peripheral wall 36a and a ceiling wall 36b that closes an upper opening of the cylindrical peripheral wall. The ceiling wall 36b has a function as a separator plate described later. In this embodiment, the strengths of the springs 38 that bias the three caps 36 are different. In addition, several slits 36c are formed in the cylindrical peripheral wall 36a of the cap 36 in the vertical direction (direction parallel to the axis). The cap 36 is fitted so that the inner surface of the cylindrical peripheral wall 36 a is in sliding contact with the outer surface of the peripheral wall of the cylindrical body 35 of the partition wall 31.

  Therefore, the cap 36 is positioned so that the ceiling wall 36 b opposes the flow of blow-by gas passing through the cylindrical body 35. The ceiling wall 36 b is maintained in contact with the gas outlet 35 b of the cylindrical body 35 by the urging force of the springs 38 having different strengths.

In the oil separator 30 configured as described above, when the differential pressure is small according to the differential pressure between the pressure corresponding to the negative pressure generated in the intake passage and the pressure in the camshaft chamber 33, the strength of the spring 38 is increased. The cap 36 having the weak ceiling wall 36b is separated upward from the upper opening end of the cylindrical body 35, and the ceiling wall 36b having a strong biasing force of the spring 38 is sequentially opened as the differential pressure increases.
That is, when the negative pressure in the intake pipe increases, the opening area of the gas passage 35a increases correspondingly. Thereby, the flow velocity of the gas ejected from the gas ejection port 35b of the gas passage can be maintained substantially constant.

  Accordingly, blow-by gas in the camshaft chamber 33 is sucked from the lower end of the cylindrical body 35 and is ejected to the separator chamber 32 through the slit 36 c of the cap 36. At that time, the blow-by gas collides with the separator surface of the ceiling wall (separator plate) 36b of the cap 36, and the mist in the blow-by gas is separated. The blowby gas from which the mist has been separated and removed in this manner is guided to the separator chamber 32 through the slit 36c, and is returned to the intake pipe (not shown) from the gas outflow port 34. On the other hand, the separated mist falls through the gas passage 35 a and is returned to the camshaft chamber 33.

  Note that when the pressure in the intake passage becomes higher than the pressure in the camshaft chamber 33, air flows backward from the intake passage toward the oil separator 30, but according to the oil separator 30 of the present invention. In this case, since the ceiling wall 36b of the cap 36 closes the gas outlet 35b of the cylindrical body 35, there is no possibility that air flows backward. Further, in the oil separator 30 of this embodiment, since the flow rate of the blow-by gas is almost constant without changing as described above, sufficient mist removal can always be ensured.

FIG. 8 shows a fourth embodiment of the oil separator according to the present invention.
In the oil separator 40, the cylinder 451 is disposed in a state where the axis of the cylinder is inclined with respect to the vertical. A separator group A in which a plurality of separators a in which a cap 461 is brought into contact with the gas outlet 451b of the gas passage 451a of the cylindrical body 451 with the same urging force is connected in series is different from the separator unit a. A separator group B, which is formed by connecting a separator unit b having a force applied to the cap 462 in series like the separator group A, is arranged in parallel.

  In the embodiment shown in FIG. 8, two separator groups A and B are provided. In the oil separator 40, the partition wall 41 is formed to be inclined as shown in FIG. 8, and a drain hole 47 is formed in the valley portion.

  In this oil separator 40, first, all caps 461 of the separator group A in FIG. Therefore, the blow-by gas in the camshaft chamber 43 passes through the cap 461 from the gas passage 451a of the left end cylinder 451 in FIG. 8, and further passes through the cap 461 from the gas passage 451a of the center cylinder 451. Further, it is ejected from the gas passage 451 a of the cylinder body 451 at the right end through the cap 461 to the separator chamber 42. At that time, the mist of the blow-by gas is separated by the cap 461 of each separator unit a, and sent to the intake pipe through the gas outflow port 44. Further, the separated mist (oil) is dropped and discharged into the camshaft chamber 43 through the gas passage 451 a and the drain hole 47 of the cylindrical body 451.

  When the negative pressure increases, all the caps 462 of the separator group B having a strong urging force, for example, in FIG. 8 are also opened. Therefore, the blow-by gas in the camshaft chamber 43 passes through the cap 462 from the gas passage 452a of the cylinder 452 at the right end in FIG. 8, and further passes through the cap 462 from the gas passage 452a of the center cylinder 452. Further, the gas is discharged from the gas passage 452 a of the left end cylindrical body 452 through the cap 462 to the separator chamber 42. At that time, blow-by gas is separated from the mist by the cap 462 of each separator unit b, and sent to the intake pipe through the gas outflow port 44. Further, the separated mist (oil) is dropped and discharged to the camshaft chamber 43 through the gas passage 452 a of the cylinder 452 and the drain hole 47.

  When the pressure in the intake passage becomes higher than the pressure in the camshaft chamber 43, air flows backward from the intake passage toward the oil separator 40. However, the oil according to the present invention causes the parator 40 to flow. Accordingly, since the ceiling walls 461b and 462b of the caps 461 and 462 block the gas ejection ports 451b and 452b of the cylindrical bodies 451 and 452, there is no possibility that air flows backward.

  Moreover, although the ceiling walls 16b, 26b, 36b are formed flat in the caps 16, 26, 36, etc. of the above embodiment, they can be formed in a conical shape as shown in FIG. In this case, the blow-by gas passing through the gas passages 15a, 25a, 35a of the cylinders 15, 25, 35, etc. becomes turbulent flow by the conical ceiling walls 16b, 26b, 36b, so that the separation performance is further improved. At the same time, it is difficult to be attracted to the wall surface of the cylinder head cover 2.

FIG. 10 shows still another embodiment of the oil separator according to the present invention.
The oil separator 50 is a cyclone oil separator. In the oil separator 50, a main body casing 59 is suspended from the lower surface of the partition wall 51, and the upper end of the main body casing 59 projects from the separator chamber 52 with the exhaust duct 55 serving as a cylinder. A cap 56 is placed over the gas outlet 55 b of the exhaust duct 55. Note that the cap 56 has a different thickness as in the first embodiment described above.

  In the oil separator 50, blow-by gas enters the main body casing 59 from the gas inlet 59a, and the mist is separated while swirling in the main body casing. The separated mist is dropped into the camshaft chamber 53 from the drain port 59b of the main body casing 59. On the other hand, the blow-by gas from which the mist has been separated is ejected from the upper opening of the exhaust duct 55 through the slit 56c of the cap 56 into the separator chamber 52 and sent to the intake pipe.

FIG. 11 shows still another embodiment of the oil separator according to the present invention.
In the oil separator 60, a plurality (three in the embodiment) of gas passages 65 b of gas passages are provided in a row in the partition wall 61, and these jet outlets 65 b are covered with leaf springs 67.

  In this oil separator 60, all gas jets 65 b are closed by leaf springs 67 in an unloaded state. When the separator chamber defined on the upper side of the partition wall 61 has a negative pressure, the separator chamber is bent upward by an amount corresponding to the negative pressure. Therefore, the gas outlet 65b is opened corresponding to the negative pressure.

  Although various embodiments of the oil separator according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and the technical idea of the present invention described in the claims is not limited thereto. Of course, it is possible to make the embodiment further various changes within the scope.

DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Cylinder head cover 10 Oil separator 11 Partition 12 Separator chamber 13 Camshaft chamber 14 Gas outflow port 15 Cylindrical body 15a Gas passage 15b Gas outlet 15c Gas inflow port 16 Cap 16a Cylindrical peripheral wall 16b Ceiling wall (separator plate)
16c Slit 17 Oil scattering prevention plate 20 Oil separator 21 Partition 22 Separator chamber 23 Camshaft chamber 24 Gas outflow port 25 Cylindrical body 25a Gas passage 25b Gas outlet 25c Gas inflow port 26 Cap 26a Cylindrical peripheral wall 26b Ceiling wall (separator plate)
26c Slit 27 Oil scattering prevention plate 30 Oil separator 31 Partition 32 Separator chamber 33 Camshaft chamber 34 Gas outflow port 35 Cylindrical body 35a Gas passage 35b Gas outlet 35c Gas inflow port 36 Cap 36a Cylindrical peripheral wall 36b Ceiling wall (separator plate)
36c Slit 37 Oil scattering prevention plate 38 Spring 40 Oil separator 41 Partition 43 Camshaft chamber 44 Gas outflow port 451, 452 Cylindrical body 451a, 452a Gas passage 451b, 452b Gas outlet 461, 462 Cap 47 Drain hole 50 Oil separator 51 Partition 52 Separator chamber 53 Camshaft chamber 55 Exhaust duct 55b Gas outlet 56 Cap 56c Slit 59 Main body casing 59a Gas inlet 59b Drain port 60 Oil separator 61 Bulkhead 65b Gas outlet 67 Leaf spring (separator plate)

Claims (6)

A separator plate is disposed so as to move against the blow-by gas passing through the gas passage, and the separator plate is urged to abut against the gas outlet of the gas passage, thereby having a check valve function. An oil separator having a gas passage formed by a cylinder, and a cylindrical cap having the separator plate as a ceiling wall and a gas ejection hole in the peripheral wall is fitted to the upper opening peripheral wall of the cylinder An oil separator characterized by being in sliding contact . 2. The oil separator according to claim 1 , wherein a plurality of separators in which a cap is brought into contact with the gas outlet of the cylindrical body with the same urging force are connected in series. 3. The oil separator according to claim 1, wherein a plurality of gas passages are formed, and a separator plate is brought into contact with each of gas outlets of the gas passages with different urging forces. 4. 4. The oil separator according to claim 3 , wherein the urging force is made different by making the thickness of the separator plate different. The oil separator according to claim 3 , wherein the biasing force is made different by changing an opening area of a gas outlet of the gas passage. The oil separator according to claim 3 , wherein the urging force is made different by pressing the separator plate with a spring having a different urging force.

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