JP4563880B2 - Parallel multiple cylinder engine - Google Patents

Description

  The present invention relates to a parallel multi-cylinder engine including a plurality of cylinders in parallel, and more particularly, to a dry sump type or semi-dry sump type engine that operates while keeping a crank chamber in a dry state as a lubrication method.

  The dry sump engine has a structure in which an oil tank is installed separately from the crankcase as an oil reservoir, and a certain amount of oil is stored in the oil tank. On the other hand, the semi-dry sump engine has a separate oil tank. For example, the lower part of the transmission chamber in the crankcase is used as an oil storage part without installing the oil, and the oil is stored in the lower part of the transmission chamber (see Patent Document 1).

  In any of the dry sump type or the semi-dry sump type, the oil after being used by lubrication, which is pumped from the oil reservoir to each oiling point of the engine by an oil pump and dropped to the bottom of the crankcase or oil pan, An oil pump or a so-called scavenging pump forcibly pumps the oil into the oil reservoir so that the crank chamber is always kept dry. As a result, the friction loss due to the agitation of the oil by the crank portion (crank web or the like) is eliminated, the engine output is improved, and the oil is stably pumped and supplied to each lubrication point.

  In the dry sump type or semi-dry sump type engine as described above, it is necessary to quickly drain the oil returning to the crank chamber during operation. In the case of a parallel multiple cylinder engine, the crank chamber is partitioned by a partition wall for each cylinder. Therefore, it is required that oil can be quickly discharged for each crank chamber for each cylinder.

Conventionally, in order to discharge oil from each crank chamber, an oil discharge port is formed on the bottom surface or side surface of one crank chamber, and a communication hole is formed in a partition wall between the crank chambers. That is, oil returning from the crankshaft or the like to the bottom surface of each crank chamber is collected in one crank chamber having the oil discharge port through the communication hole of the partition wall, and is discharged from one oil discharge port. It has become.
JP-A-6-288466

  In a dry sump type or semi-dry sump type parallel multiple cylinder engine, as a method of discharging the oil in each crank chamber, a communication hole is formed in the partition wall between the crank chambers as described above, and one crank chamber having an oil discharge port is formed. If a system is adopted in which the oil in other crank chambers is merged and all the oil is discharged from the one crank chamber, the oil in the crank chamber that does not have an oil discharge port passes through the communication hole and is temporarily discharged. It must flow to the crank chamber having the outlet, and coupled with the difficulty of securing a large communication hole in the partition wall supporting the crankshaft, the crank chamber oil, particularly the crank chamber having no oil discharge port. It is difficult to drain the oil quickly. In addition, an oil passage surface that is inclined with respect to a horizontal surface must be formed on the bottom surface of the crank chamber in order to allow oil to flow to the one crank chamber, so that the bottom surface shape of each crank chamber is not uniform. Become.

  In the parallel multi-cylinder engine, the oil returning to the crank chamber for each cylinder can be discharged quickly for each crank chamber, thereby improving the engine output and making the crankcase easy to process. It aims to be able to do it.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present application is directed to a parallel multi-cylinder engine in which a plurality of cylinders are provided in parallel and an oil pan is attached to an oil pan attachment portion formed on the lower surface of the crankcase. An oil recovery chamber that communicates with the suction portion of a scavenging pump that forms an oil discharge port in the bottom surface of each crank chamber divided for each time and pumps oil to an oil storage portion that is isolated from the crank chamber, Provided in the oil pan below the bottom wall of the chamber, the oil discharge port communicates with the oil recovery chamber, and at least a part of each oil discharge port is an oil recovery formed on the bottom wall of the crank chamber The oil recovery passage communicates with the oil recovery chamber through a passage, and the oil recovery passage includes a passage forming groove having an open lower end formed on a bottom wall of the crank chamber, and a passage forming groove. It is composed of a bottom plate for closing the ends.

  According to the above configuration, in a semi-dry sump type (or dry sump type) parallel multi-cylinder engine, oil can be discharged independently from the crank chamber for each cylinder, so that oil can be quickly discharged from each crank chamber during engine operation. All the crank chambers can be kept in a good dry state, and power loss due to oil agitation can be efficiently prevented.

  According to the above configuration, the volume and arrangement position of the oil recovery chamber do not need to be widely formed so as to cover all the oil discharge ports, and the degree of freedom in designing the volume and arrangement position of the oil recovery chamber is increased.

  According to the above configuration, the oil recovery passage can be easily formed by casting and the plate member without performing special pipe piping.

According to a second aspect of the present invention, in the parallel multiple cylinder engine according to the first aspect, a strainer is housed in the oil recovery chamber.

  According to the above configuration, the strainer can be arranged by effectively using the space below the bottom wall of the crank chamber or the space in the oil pan, and the oil recovered from each crank chamber in the parallel multi-cylinder engine is summarized. It can be filtered and recovered in the oil reservoir.

According to a third aspect of the present invention, in the parallel multi-cylinder engine according to the first or second aspect , an oil pipe space is formed in the oil pan mounting portion, and the oil recovery passage is formed in the oil pipe space. An oil supply pipe is provided for supplying oil to each lubrication point of the engine.

  According to the above configuration, the space in the oil pan mounting portion can be effectively used for the oil supply path.

According to a fourth aspect of the present invention, in the parallel multi-cylinder engine according to any one of the first to third aspects, the lower part of the transmission chamber in the crankcase serves as the oil reservoir, and the bottom wall of the crank chamber An oil suction chamber isolated from the oil recovery chamber is formed below, and the oil suction chamber communicates with a suction portion of an oil pump for supplying oil to each lubrication point of the engine and the oil storage chamber. It communicates with the department.

  According to the above configuration, a semi-dry sump type in which the lower part of the mission chamber is an oil reservoir is not required, so that a separate oil tank is not required, and the cost and space for the tank can be eliminated.

According to a fifth aspect of the present invention, in the parallel multi-cylinder engine according to the fourth aspect, the scavenging pump and the oil pump are disposed in the transmission chamber, and a discharge portion of the oil pump is the oil pan mounting portion. The main gallery communicates with the oil supply pipe disposed in the pipe space.

  According to the above configuration, since the oil supply path from the oil pump to the main gallery is formed using the oil piping in the oil pan mounting portion, the space in the oil pan mounting portion can be used effectively and the oil piping Even if oil leaks at the connection part, leakage to the outside is prevented by the oil pan, and the oil leaked into the oil pan can be automatically sucked again by the oil pump and used for lubrication. It is.

According to a sixth aspect of the present invention, in the parallel multi-cylinder engine according to any one of the first to fifth aspects, the upper end of the peripheral wall of the oil recovery chamber of the oil pan is attached to the oil pan mounting portion on the lower surface of the crankcase. A mounting surface for the oil recovery chamber corresponding to the mating surface is formed, a portion communicating with the passage groove is opened in the mounting surface, and the opening portion is substantially flush with the mounting surface for the oil recovery chamber. A mounting surface complementary member is attached.

  According to the above configuration, the oil recovery passage can be easily formed as a passage formation groove at the time of casting the crankcase, and the sealing performance of the entire circumference of the oil recovery chamber can be secured by attaching the mounting surface complement member.

  According to the present invention, in a parallel multi-cylinder engine provided with a plurality of crank chambers in parallel, the oil returning to the crank chamber for each cylinder can be quickly discharged for each crank chamber, eliminating the stirring resistance due to oil, and the engine output The crankcase can be easily manufactured and processed.

  FIGS. 1 to 26 show an example in which the lubricating device according to the present invention is applied to a parallel two-cylinder engine for a motorcycle, and particularly an example in which the lubricating device is applied to a semi-dry sump type lubricating device.

[Crankcase shape]
FIG. 1 is a side view of the crankcase 1 shown with the clutch cover 88 (see FIG. 2) removed. For convenience of explanation, the side on which the cylinder 5 is disposed (vehicle traveling side) is referred to as the “front side of the crankcase 1. In the following description, the left and right direction (the axial direction of the crankshaft) when viewed from the rear, that is, when viewed from the rider, is referred to as the “left and right direction” of the crankcase 1.

  In FIG. 1, the crankcase 1 has an upper and lower split structure in which an upper crankcase member 2 and a lower crankcase member 3 are joined by a mating surface S, and a cylinder is formed on the upper surface of the front half of the upper crankcase member 2. Although not shown, a cylinder head and a head cover are sequentially fastened to the upper surface of the cylinder 5. The front half of the crankcase 1 is a crank chamber 10 (see FIGS. 3 and 4) for housing the crankshaft 7, and a balancer shaft 8 is disposed at the front of the crank chamber 10, and the balancer shaft A water pump 9 is provided at the right end of 8.

  The rear half of the crankcase 1 is a mission chamber 11 (see FIGS. 3 and 4) in which a cassette type mission assembly M is accommodated. The cassette type transmission assembly M supports a shift input shaft 14, a shift output shaft 15, a change drum 16, a shift fork shaft 17, and the like on a shaft support member 13 separate from the crankcase 1. Thus, the mission assembly M as a unit is inserted into the mission chamber 11 from the right side, and the shaft support member 13 is bolted to the mission mounting wall 41 formed on each crankcase member 2, 3 (one bolt Are attached detachably. A drive sprocket 25 for driving the pump is attached to the right end portion of the input shaft 14 and a multi-plate friction clutch 18 indicated by an imaginary line is attached. A pump drive chain 27 is wound between the drive sprocket 25 and the sprocket 26 of the common pump shaft 24 disposed at the front lower end of the mission chamber 11, and the rotation of the input shaft 14 is rotated around the common pump shaft 24. To communicate.

  An oil pan mounting portion 20 that projects downward is formed integrally with the lower crankcase member 3 on the lower surface of the bottom wall of the lower crankcase member 3, and a lower end surface of the oil pan mounting portion 20 is inclined forward and downward. An oil pan mounting surface 20 a is formed, and an oil pan 23 is fastened to the oil pan mounting surface 20 a by a plurality of mounting bolts 22.

  FIG. 25 is a left side view of the crankcase 1. The shaft core O 1 of the crankshaft 7, the shaft core O 6 of the balancer shaft 8, and the shaft core O 3 of the output shaft 15 are aligned with the upper and lower crankcase members 2 and 3. Located on the surface S, the axis O2 of the input shaft 14 is located above the mating surface S, and the axis O4 of the change drum 16 is located below the mating surface S. A change shaft 19 having a change pedal is disposed below the change drum 16.

  FIG. 3 is a simplified perspective view of the lower crankcase member 3 as viewed from the upper right front, and FIG. 4 is a perspective view of the lower crankcase member 3 as viewed from the upper right rear. In FIG. Therefore, the crank chamber 10 is partitioned into a left crank chamber (first crank chamber) 10L and a right crank chamber (second crank chamber) 10R by a partition wall 29 formed at the center in the left-right direction. In each of the left and right crank chambers 10L and 10R, a crank portion (web or the like) connected to the piston of each cylinder is housed. The upper and lower side walls 30L, 30R of the crank chamber 10 and the upper end surfaces of the intermediate partition walls 29 are respectively formed with halved bearing recesses 31 for supporting the crankshaft, and the left and right side walls 30L, 30R of the crank chamber 10 A halved bearing recess 32 for supporting the balancer shaft is formed in the front part. An oil supply hole 35 for crankshaft lubrication is opened at the lower end of each bearing recess 31 for supporting the crankshaft, and a fastening bolt insertion hole 36 is formed before and after each bearing recess 31. .

  In FIG. 4, a clutch chamber 12 is formed on the right side of the mission chamber 11 via the mission mounting wall 41, and the lower portion of the mission chamber 11 and the lower portion of the clutch chamber 12 are used as an oil reservoir. A partition wall 40 a having a height corresponding to the mating surface S is formed between the mission chamber 11 and the crank chamber 10, and a partition wall 40 b lower than the mating surface S is formed between the clutch chamber 12 and the crank chamber 10. Is formed. In addition, a communication hole 42 is formed at the lower end of the mission mounting wall 41 so as to allow oil to flow between the lower end of the mission chamber 11 and the lower end of the clutch chamber 12. The lower part of the mission chamber 11 can be used simultaneously as an oil reservoir.

  The left side wall 44 of the mission chamber 11 is formed with a halved bearing recess 45 for supporting the output shaft, a cylindrical recess 46 for supporting the change drum, and a recess 47 for the shift fork support shaft. Has been.

  The lower end portion of the partition wall 40a, that is, the front lower end portion of the mission chamber 11, returns from a feed oil pump 50 for pumping oil in the oil reservoir to each lubrication location, and a lubrication location such as a crankshaft. A scavenging pump (recovery oil pump) 51 for collecting the used oil in the oil reservoir is provided in parallel on the shaft core O5 of the common pump shaft 24.

[Crank chamber oil discharge structure]
FIG. 5 is a plan view of the lower crankcase member 3. A left oil discharge port 53 is formed in a substantially middle portion (generally the lowest portion) in the front-rear direction on the bottom surface of the left crank chamber 10L, and the bottom surface of the right crank chamber 10R. The right oil discharge port 54 is formed in the rear half portion (generally the lowest portion), so that the oil returning from the crankshaft portion to the bottom surfaces of the crank chambers 10L, 10R respectively flows into the left and right crank chambers 10L, 10R. The oil discharge ports 53 and 54 are independently discharged every time.

  On the lower surface of the bottom wall of the lower crankcase member 3 (the bottom walls of the crank chambers 10L and 10R), an oil recovery passage 55 is formed extending rightward and rearward from the left oil discharge port 53 across the lower portion of the partition wall 29. The right end of the oil recovery passage 55 communicates with an oil recovery chamber communication space 56 formed below the right oil discharge port 54. The space 56 is an oil recovery chamber 60 described later. Communicating with

[Shape of oil pan]
FIG. 12 is a perspective view of the oil pan 23 as viewed from the upper left front, and FIG. 13 is a plan view of the oil pan 23. In FIG. 12, the oil pan 23 is formed in a substantially right triangle shape when viewed in the crankshaft direction, that is, in a side view, the upper end mating surface 23a is inclined forward and the bottom wall 23b is substantially horizontal. ing. The oil recovery chamber 60 is formed in the oil pan 23 so as to be adjacent to the right side wall of the oil pan 23, and the remaining large space partitioned by the peripheral wall 61 of the oil recovery chamber 60 is oil oil. It is a reservoir / oil suction chamber 62.

  A circular placement surface 62a for placing a strainer (primary filter) 64 is formed on the bottom surface of the oil suction chamber 62, and an arc-shaped baffle wall 62b is erected on the front portion of the placement surface 62a. Has been.

  A strainer 65 made of a wire mesh is accommodated in the oil recovery chamber 60 and fixed to the upper end portion of the peripheral wall 61 of the oil recovery chamber 60 by a pressing plate 66 and bolts 67. The upper end alignment surface 61 a of the peripheral wall 61 is formed in the same plane as the upper end alignment surface 23 a of the outer peripheral wall of the oil pan 23.

  A recovery oil suction passage 69 having a lower end communicating with the lower end of the oil recovery chamber 60 is formed on the rear side of the oil recovery chamber 60, and an upper end mating surface 69 a of the recovery oil suction passage 69 is also formed in the oil pan 23. Are formed in the same plane as the mating face 23a. That is, the upper end aligning surface 23 a of the oil pan 23, the upper end aligning surface 61 a of the peripheral wall 61 of the oil recovery chamber 60, and the upper end aligning surface 69 a of the recovered oil suction passage 69 are aligned.

  FIG. 19 is a cross-sectional view taken along XIX-XIX in FIG. 5. By providing the mating surfaces 23 a, 61 a, 69 a on the oil pan 23 side on the same surface as described above, these mating surfaces 23 a, 61 a, 69 a, A common gasket 58 can be sandwiched between the oil pan mounting surface 20a on the pan mounting portion 20 side, the lower end mounting surface 57a of the peripheral wall 57 of the space 56 and the lower end surface of the suction portion 51b of the scavenging 51. It has become.

The oil recovery chamber 60 is formed immediately below the right oil discharge port 54 of the right crank chamber 10R and the space portion 56 for communicating with the oil recovery chamber, and the oil discharged from the right oil discharge port 54 is the space portion 56. The oil flows directly into the oil recovery chamber 60 through the passage. On the other hand, oil discharged from the left oil discharge port 53 of the left crank chamber 10L in FIG. 5 passes through the oil recovery passage 55 formed on the lower surface of the bottom wall of the crankcase 1 (the bottom walls of the crank chambers 10L and 10R). It passes through the space 56 and flows into the oil recovery chamber 60 below.

[Strainer]
14 is a plan view of the holding plate 66, FIG. 15 is a plan view of the strainer 65, FIG. 16 is a view taken along the arrow XVI in FIG. 15, FIG. 17 is a view taken along the arrow XVII in FIG. As shown in FIGS. 16 and 17, it is formed in a quarter-divided dome shape, and an attachment flange 65 a is provided at the upper end, and the attachment flange 65 a is fixed by a pressing plate 66 shown in FIG. 14.

[Oil pump and scavenging pump]
FIG. 23 is a cross-sectional view of the feed oil pump 50 and the oil recovery scavenging pump 51 (XXIII-XXIII cross-sectional view of FIG. 1), both of which employ a trochoid pump. A cylindrical outer casing part 70 is formed at the lower end of the partition wall 40a of the lower crankcase member 3, and an intermediate casing member 71 is fitted into the outer casing part 70, and the right-side open end of the intermediate casing member 71 is By closing with the pump cover 72, the casing of the scavenging pump 51 is configured on the right side, and the casing of the oil pump 50 is configured on the left side.

  Inner rotors 50 a and 51 a disposed in the casings of the pumps 50 and 51 are fixed to the common pump shaft 24, and power is transmitted through the sprocket 26 and the chain 27.

  In FIG. 19, the suction part 51b of the scavenging pump 51 opens downward into the oil pan 23, communicates with the upper end of the recovered oil suction passage 69 in a liquid-tight state, and the discharge part 51c is connected to the mission chamber 11. It opens to the lower part (oil storage part). That is, the scavenging pump 51 sucks the oil returned to the oil recovery chamber 60 from the suction portion 51b through the recovery oil suction passage 69 and discharges it from the discharge portion 51c to the mission chamber 11.

[Oil supply path from oil pump to main gallery]
18 is an XVIII-XVIII cross-sectional view of FIG. 5 (XVIII-XVIII cross-sectional view of FIG. 7). The suction portion 50b and the discharge portion 50c of the feed oil pump 50 are connected to the oil pan from the bottom wall of the lower crankcase member 3. 23 is opened downward toward the oil suction chamber 62, and the upper end portion of the funnel-shaped strainer (primary filter) 64 is connected to the suction portion 50 b so as to suck the oil in the oil suction chamber 62. It has become. A U-shaped oil supply pipe 73 extending forward in the oil pan mounting part 20 and the oil pan 23 is connected to the discharge part 50 c, and the front end of the oil supply pipe 73 is the front end of the oil pan mounting part 20. It is connected to an oil supply passage 74 formed in the section. The oil supply passage 74 communicates with an unpurified side of an oil filter (secondary filter) 75 fixed to the front end surface of the oil pan mounting portion 20, and a purification side outlet 75 a of the oil filter 75 is connected to a lower crankcase member. 3 communicates with an oil supply passage 91 formed on the bottom wall and extending rearward, and the oil supply passage 91 communicates with a main gallery 92 formed on the bottom wall of the lower crankcase member 3. That is, oil discharged from the oil pump 50 passes through the oil supply pipe 73, the oil supply passage 74, the oil filter 75, and the oil supply passage 91 in the oil pan 23, and enters the main gallery 92 in the bottom wall of the crankcase 1. It comes to be supplied.

[Shape inside the oil pan mounting part]
6 to 9 show the oil pan mounting portion 20 on the lower surface of the lower crankcase member 3, FIG. 6 is a perspective view seen from the front lower side, and FIG. 7 is a bottom view showing a state in which various oil piping parts are mounted. 8 is a bottom view showing a state in which only the bottom plate 78 for forming the oil recovery passage is attached, and FIG. 9 is a bottom view showing a state in which all the piping parts and the like are removed.

  In FIG. 8, in the oil pan mounting part 20, as described above, the suction part 50b of the oil pump 50, the discharge part 50c of the oil pump 50, and the suction part 51b of the scavenging pump 51 are formed at the rear part. A space portion 56 for communicating with the oil recovery chamber is formed, and an oil recovery passage 55 is formed from the left front end portion to the space portion 56. In addition to this, a pair of front and rear connection ports 81 and 82 for connecting the mission lubrication oil supply pipe are formed, and an oil supply pipe 94 for mission lubrication is provided between the connection ports 81 and 82 as shown in FIG. It is attached.

[Structure of peripheral wall of space for oil recovery passage and oil recovery chamber communication]
In FIG. 8, the oil recovery passage 55 includes a passage formation groove 77 formed on the lower surface of the bottom wall of the lower crankcase member 3 (the bottom walls of the crank chambers 10 </ b> L and 10 </ b> R) and an open lower end, and the passage formation groove 77. The bottom plate 78 is made of a sheet metal fastened to the lower end surface of the plate by a bolt 79. By the bottom plate 78, as shown in FIG. 20 which is a XX-XX section of FIG. The interior is isolated from the oil suction chamber 62 in the oil pan 23 in a liquid-tight state.

  In FIG. 9, the lower end surface 80 a of the side wall 80 of the passage forming groove 77, together with the lower end mounting surface 57 a of the peripheral wall 57 of the oil recovery chamber communication space 56 and the lower end surface of the oil suction port 51 b of the scavenging pump 51, It is formed in the same plane as the oil pan mounting surface 20a.

  Of the lower end mounting surface 57a of the peripheral wall 57 of the oil recovery chamber communication space portion 56, a portion P that intersects the passage forming groove 77 is opened to enable casting. In order to complement the sealing performance of the opening portion P, a pair of arc-shaped stepped portions as mounting surface complementing member support seats 96 are formed on the lower end surface 80a of the side wall 80 of the passage forming groove 77 in the vicinity of the opening portion P. As shown in FIG. 8, a mounting surface complement member 95 is fitted into the support seat 96 and fixed from below by a bottom plate 78. The mounting surface complement member 95 completes an unbroken mounting surface (seal surface) along with the mounting surface 57 a formed on the peripheral wall 57 around the space portion 56. The attachment surface complement member 95 is formed in a disk shape as shown in FIG.

  In FIG. 7, in a state where the mounting surface complement member 95 is fitted into the support seat 96, the lower end mounting surface of the mounting surface supplement member 95 is the oil pan mounting surface 20a and the lower end mounting surface 57a of the peripheral wall 57 of the space 56. It is almost the same surface. Thereby, the gasket 58 portion disposed over the entire mating surface 61a of the peripheral wall 61 of the oil recovery chamber 60 shown in FIGS. 22 and 19 which is a XXII-XXII cross section of FIG. 5 is replaced with the oil pan mounting surface 20a and the space portion 56. The lower end mounting surface 57a of the peripheral wall 57 and the lower end surface 95a of the mounting surface complementary member 95 in FIG.

  FIG. 10 is a bottom view of the bottom plate 78. The bottom plate 78 is formed with a plurality of bolt insertion holes 85 in the periphery, and a small diameter adjustment hole for equalizing the oil level in the vicinity of the front end. 84 is formed. In FIG. 20, the adjustment hole 84 communicates between the oil recovery passage 55 and the oil suction chamber 62 of the oil pan 23. When the engine is stopped, the transmission chamber 11 shown in FIGS. 3 and 4 is used. The oil in the oil reservoir is moved gradually toward the crank chamber 10 to equalize the oil level in the mission chamber 11 and the crank chamber 10, but the engine is running by forming a small diameter. In this case, only a small part of the recovered oil flowing in the oil recovery passage 55 is discharged to the oil suction chamber 62, and the oil flow into the oil recovery chamber 60 is hardly affected.

[Oil reservoir and oil inspection window]
As described above, the oil reservoir as a semi-dry sump type lubricating device includes a lower portion of the mission chamber 11 shown in FIGS. 3 and 4 and a clutch chamber 12 communicating with the lower portion of the mission chamber 11 via the communication hole 42. The lower part and the oil suction chamber 62 of the oil pan 23 in FIG. 12 communicating with the mission chamber 11 through the communication hole 86 are configured.

  FIG. 2 is a right side view of the clutch cover 88 that covers the right opening of the clutch chamber 12. A transparent oil inspection window 89 is provided below the clutch cover 88, and the oil in the clutch chamber 12 is externally provided. The level can be checked. The oil inspection window 89 is preferably located at a height at which the oil level L1 in the clutch chamber 12 when the operation is stopped is visible from the outside. The oil level L1 at the time of the stop of the operation is such that the oil in the oil storage portion including the inside of the clutch chamber 12 is stopped after a certain time has passed, and the oil in the oil reservoir, such as FIG. Is the oil level when the oil level in the oil reservoir and the crank chamber 10 is made uniform.

  On the other hand, the oil level L2 at the time of operation shown in FIG. 2 is the same as that at the time of the operation stop because the oil in the crank chamber 10 (FIG. 3 and the like) is forcibly pumped to the oil reservoir by the scavenging pump 51. The oil level is higher than the oil level L1, for example, the height corresponding to the height of the partition wall 40b (FIG. 3 and the like) between the clutch chamber 12 and the crank chamber 10. The multi-plate friction clutch 18 mounted on the input shaft 14 and the ring gear provided in the clutch housing of the clutch 18 are disposed at a high position where the oil level L2 during operation is not immersed in oil. . That is, by increasing the position of the input shaft 14, the position of the clutch 18 is increased, so that no power loss due to oil agitation occurs during operation.

[Oil supply path from main gallery to crankshaft lubrication point]
FIG. 21 is a cross section taken along the line XXI-XXI of FIG. 5, and the main gallery 92 formed on the bottom wall of the lower crankcase member 3 is located substantially directly below the crankshaft core O1 and extends in the left-right direction. Oil communicates with the lower ends of the oil supply holes 35 formed in the left and right side walls 30L, 30R of the crank chamber 10 and the intermediate partition wall 29, and supplies oil to the bearing recesses 31 for supporting each crankshaft. An oil supply pipe 130 for balancer shaft lubrication is connected to the left end portion of the main gallery 92.

[Oil supply path from main gallery to mission lubrication point]
FIG. 24 shows an oil supply path for mission lubrication, and is a cross-sectional view seen from the front, so that the actual left-right direction and the left-right direction on the drawing are reversed. An oil supply passage 100 for mission lubrication extending upward from the connection port 82 is formed in the left side wall 44 of the mission chamber 11 of the lower crankcase member 3. As described above, the connection port 82 communicates with the main gallery 92 via the oil supply pipe 94 for mission lubrication. The left side wall 48 of the transmission chamber 11 of the upper crankcase member 2 is formed with an oil supply passage 101 for mission lubrication that communicates with the upper end of the oil supply passage 100 for mission lubrication of the lower crankcase member 3. The supply passage 101 extends upward and opens toward the left (outside of the crankcase) at a position near the front of the input shaft 14. On the outer side surface of the left side wall 48 of the transmission chamber 11 of the upper crankcase member 2, an oil passage configuration 103, which is a separate member from the upper crankcase member 2, is detachably fixed. The oil passage forming body 103 has a mission lubrication oil supply passage 104 extending in the length direction, an oil inlet 105 communicating with the upper end opening of the upper end oil supply passage 101 of the upper crankcase member 2, and an input shaft 14. A first oil outlet 106 located on the extension of the shaft core O2 and communicating with the oil hole 110 of the input shaft 14 via the throttle 111, and a second oil outlet 107 opened at a position rearward of the input shaft 14 The oil inlet 105 and the oil outlets 106 and 107 are both open to the right.

  The second oil outlet 107 communicates with an oil hole 112 formed in the left side wall 48 of the transmission chamber 11 of the upper crankcase member 2. An oil communication pipe 115 is press-fitted and fixed to the oil hole 112, and the oil communication pipe 115 extends to the right and passes through the through hole 116 of the transmission assembly mounting wall 41 of the upper crankcase member 2, and the right end portion. The joint portion with seal 115 a protrudes into the clutch chamber 12.

  The upper end connection port 120a of the oil supply passage 120 for mission lubrication formed in the shaft support member 13 of the mission assembly M is detachably fitted to the joint portion 115a with seal, and is detachably fitted in the left and right direction (the crankshaft of the crankshaft). (Parallel to the axial direction). An oil supply passage 120 in the shaft support member 13 extends downward, and a lower end portion communicates with the oil hole 122 of the output shaft 15 through a throttle 121.

  FIG. 25 is a left side view of the crankcase 1, and the oil passage forming body 103 is detachably attached to the left side wall 48 of the upper crankcase member 2 by a bolt 125. The balancer shaft lubricating oil communication pipe 130 extends forward and is connected to an oil supply passage 131 in the vicinity of the balancer shaft 8 so as to supply oil to the bearing portion of the balancer shaft.

[Oil flow throughout the engine]
FIG. 26 is a schematic diagram simply summarizing the flow of oil in the entire engine, and the oil in the oil storage section composed of the mission chamber 11 and the like is fed from the oil suction chamber 62 in the oil pan 23 by the feed oil pump 50. Then, the oil is sucked through the strainer (primary filter) 64, pressurized, and pumped forward from the discharge part 50c through the oil supply pipe 73 to the oil filter (secondary filter) 75 at the front end of the oil pan mounting part 20. After entering and purifying, it is pumped to the main gallery 92 via the oil supply passage 74.

  Part of the oil pumped to the main gallery 92 is diverted to the three oil supply holes 35 for lubricating the crankshaft, and lubricates each journal portion of the crankshaft 7 (FIG. 1).

  In FIG. 26, some of the oil in the main gallery 92 includes a mission lubrication oil supply pipe 94, a mission lubrication oil supply passage 100 of the lower crankcase member 3, and an upper crankcase member 2 for mission lubrication. The oil supply passage 101 is supplied to the oil supply passage 104 for mission lubrication of the oil passage formation body 103. A part of the oil in the oil supply passage 104 is supplied to the oil hole 110 of the input shaft 14 in FIG. 24 through the first oil outlet 106 and the throttle 111, and the rest is the second oil outlet 107. Then, the oil is supplied to the oil hole 122 of the output shaft 15 through the oil communication pipe 115, the oil supply passage 120 for transmission lubrication in the transmission assembly support member 13, and the throttle 121.

    The oil supplied to the oil holes 110 and 122 of the input shaft 14 and the output shaft 15 is lubricated to the fitting portion of the transmission gear, lubricates the fitting portion of the transmission gear, and the oil used for transmission lubrication is It is returned directly to the oil reservoir at the bottom of the mission chamber 11.

  On the other hand, the oil used for crankshaft lubrication from the oil supply hole 35 in FIGS. 3 and 4 returns to the bottom surfaces of the left and right crank chambers 10L and 10R, and is discharged independently from the oil discharge ports 53 and 54, respectively. The In FIG. 19, the oil discharged from the oil discharge port 54 of the right crank chamber 10 </ b> R passes through the oil recovery chamber communication space 56, is discharged to the oil recovery chamber 60 directly below, and is filtered to the strainer 65. In FIG. 5, the oil discharged from the oil discharge port 53 of the left crank chamber 10L reaches the space portion 56 through the oil recovery passage 55, and together with the oil from the right crank chamber 10R from the space portion 56, It is discharged into the oil recovery chamber 60 of FIG. 19 and filtered.

  The oil filtered by the strainer 65 is sucked up by the scavenging pump 51 through the recovered oil suction passage 69 and discharged to the lower part (oil storage part) of the mission chamber 11.

[Change in oil level]
During engine operation, the scavenging pump 51 always forcibly discharges the oil in the crank chamber 10, so that the crank chamber 10 is kept dry. On the other hand, in the oil reservoir, the oil level rises to the vicinity of the upper end of the partition wall 40b at the front end of the clutch chamber 12, as indicated by level L2 in FIG. As described above, the input shaft 14 is disposed higher than the oil level L2 during the operation, so that the housing and the ring gear of the clutch 18 attached to the end of the input shaft 14 are immersed in the oil. There is no stirring resistance.

  Further, when the oil in the left crank chamber 10L in FIG. 5 passes through the oil recovery passage 55 during engine operation, the oil flowing through the oil recovery passage 55 is adjusted via the adjustment hole 84 in the bottom plate 78 in FIG. Although some of the oil may leak into the oil suction chamber 62, the amount of leakage is very small compared to the total amount of oil flowing in the oil recovery passage 55 due to the small diameter of the adjustment hole 84. The effect is hardly affected.

  When the operation is stopped, immediately after the stop, the oil level in the oil reservoir is the same as the oil level L2 during the operation, and the crank chamber 10 is in a dry state. The oil gradually returns from the respective lubrication points such as the bearing of the crankshaft 7, the bearing of the camshaft, and the piston, and the oil in the oil storage portion passes through the adjustment hole 84 of the bottom plate 78 of the oil recovery passage 55. As shown by the oil level L1 in FIG. 1, the oil in the reservoir and the oil in the crank chamber 10 become substantially the same level. By checking the equalized oil level from the oil check window 89 of the clutch cover 88 in FIG. 2, it is possible to check the oil amount in the entire engine.

  That is, the oil level of the entire engine can be easily confirmed by checking the oil level at one place in the oil reservoir.

  Incidentally, when the adjustment hole 84 is not formed, the oil level is not uniform even when the operation is stopped, and only the oil amount in the oil reservoir is obtained only by the oil check window 89 provided in the clutch cover 88. It cannot be confirmed, and the amount of oil in the crank chamber 10 cannot be confirmed. Therefore, it becomes difficult to accurately check the residual oil amount of the entire engine.

[Effect of the embodiment of the present invention]
(1) In a semi-dry sump parallel two-cylinder engine, oil discharge ports 53 and 54 are formed in the bottom surfaces of the left and right crank chambers 10L and 10R, respectively, and oil is discharged independently for each crank chamber 10L and 10R. Therefore, oil can be quickly discharged from the crank chambers 10L, 10R, and the crank chambers 10L, 10R can be kept in a dry state while the engine is running. Can be efficiently prevented.

(2) On the other hand, for example, the oil discharged from the left crank chamber 10L is joined to the oil discharged from the right crank chamber 10R by the oil recovery passage 55 formed in the bottom wall of the crankcase 1, and the oil recovery chamber 60 Since the oil from the crank chamber without the oil discharge port flows into the crank chamber with the oil discharge hole through the small communication hole of the partition wall as in the prior art, the oil flow is smoothly performed. Sex is disturbed and does not interfere with dryness.

(3) The oil recovery passage 55 includes a passage forming groove 77 having an open lower end formed in the bottom wall of the lower crankcase member 3 and a bottom plate 78 made of sheet metal that closes the lower end of the passage forming groove 77. Therefore, no special piping for oil recovery is required, and the oil recovery passage 55 can be easily formed by casting and sheet metal processing of the bottom plate 78.

(4) Since the strainer 65 is disposed in the oil recovery chamber 60 in the oil pan 23, the limited space of the oil pan 23 can be used effectively, and the recovery is performed from each of the crank chambers 10L and 10R. The oil to be collected can be filtered together and collected in the oil reservoir.

(5) An oil piping space is formed in the oil pan mounting portion 20, the oil recovery passage 55 is formed in the oil piping space, and an oil supply pipe 73 and an oil supply pipe 94 for mission lubrication are arranged. Therefore, the space in the oil pan mounting portion 20 can be used effectively. Moreover, even if oil leakage occurs at the pipe joint location, it will leak into the oil pan 23 and will not leak to the outside.

(6) A partition wall 40a is formed between the crank chamber 10 and the mission chamber 11, and the lower portion of the mission chamber 11 is used as an oil reservoir, so that a semi-dry sump type is used. The cost and space for the tank can be eliminated. In addition to this, a partition wall 40b is also formed between the crank chamber 10 and the clutch chamber 12, and the lower portion of the clutch chamber 12 is also a component of the oil reservoir, so that the amount of oil stored can be increased.

(7) The oil recovery chamber mounting surface joined to the oil pan mounting portion 20 to the upper end mating surface 61a of the peripheral wall 61 of the oil recovery chamber 60 of the oil pan 23, that is, the peripheral wall 57 of the oil recovery chamber communication space portion 56. A lower end mounting surface 57a is formed, a portion of the mounting surface 57a that intersects the passage forming groove 77 is opened (P), and the opening portion P is flush with the mounting surface 57a of the space peripheral wall 57. Since the mounting surface complementary member 95 is fitted, the oil recovery passage 55 can be easily formed as the passage forming groove 77 at the time of casting the crankcase 1, and by fitting the mounting surface complementary member 95, The sealability of the entire circumference of the oil recovery chamber 60 can be ensured.

(8) Since the bottom plate 78 of the oil recovery passage 55 is formed with a small-diameter adjustment hole 84 that communicates the transmission chamber 11 side and the crank chamber 10 side (in the oil recovery passage 55), the operation is stopped, After a certain period of time, the oil in the oil storage section composed of the mission chamber 11, the clutch chamber 12, and the oil suction chamber 62 and the oil in the crank chamber 10 are made uniform to reach substantially the same oil level L1. Therefore, for example, the entire remaining oil amount in the engine can be confirmed by forming only one level inspection window 89 in the clutch cover 88 that can inspect only the oil level in the clutch chamber 12.

(9) Since the adjustment hole 84 for equalizing the oil level is formed at a low position near the bottom wall of the oil pan 23, the oil level can be quickly equalized by fully utilizing the head pressure. It can be carried out.

(10) Since the adjustment hole 84 is formed in the bottom plate 78 made of sheet metal, for example, the processing is simpler than the case where the crankcase 1 is formed.

[Other embodiments]
(1) It is also possible to apply to a parallel cylinder engine having three or more cylinders.

(2) The adjustment hole for equalizing the oil level can be formed in the bottom wall of the crankcase 1. For example, as indicated by phantom lines in FIGS. 7 to 9, the adjustment hole 150 can be formed near the front end of the oil pan mounting portion 20.

(3) The above embodiment is a semi-dry sump type lubrication device using the mission chamber as an oil reservoir, but a dry sump type lubrication device in which a separate oil tank is installed outside the crankcase. Is also possible.

(4) In the above embodiment, the oil recovery chamber 60 is disposed below the bottom wall of one crank chamber 10R, and the oil in the crank chamber 10R is directly discharged to the oil recovery chamber 60 and the other crank chamber 10L. The oil is discharged into the oil recovery chamber 60 through the oil recovery passage 55. However, the oil recovery chamber 60 is formed wide so as to extend to the left and right oil discharge ports 53, 54, and the oil recovery passageway is formed. It can also be set as the structure which does not exist at all.

(5) Although the oil pan 23 of the above-described embodiment is formed in a container shape having a certain volume, a flat plate member that functions almost only as a bottom plate is attached to the oil pan mounting portion as an oil pan. It can also be applied to structures.

Industrial application fields

  The present invention is applicable not only to motorcycle engines but also to other vehicle engines such as automobiles.

1 is a right side view of a crankcase that is a parallel two-cylinder engine for a motorcycle equipped with a lubricating device according to the present invention, with a clutch cover removed. It is a right view of the clutch cover of the crankcase of the engine of FIG. It is the perspective view which looked at the lower crankcase member of Drawing 1 from the front right upper part. It is the perspective view which looked at the lower crankcase member of FIG. 1 from the upper right rear. It is a top view of the lower crankcase member of FIG. It is the perspective view which looked at the oil pan attaching part of the lower crankcase member of FIG. 1 from the front lower side. FIG. 2 is a bottom view of the lower crankcase member of FIG. 1 with the oil pan removed. FIG. 2 is a bottom view of the lower crankcase member of FIG. 1, and is a bottom view showing an oil pan and piping in an oil pan mounting portion removed. FIG. 2 is a bottom view of the lower crankcase member of FIG. 1, with the oil pan, piping in the oil pan mounting portion, and the bottom plate also removed. It is a bottom view of a bottom plate. It is a perspective view of a mounting surface complement member. It is the perspective view which looked at the oil pan of FIG. 1 from the upper left front. It is a top view of the oil pan of FIG. It is a top view of the holding plate of a strainer. It is a top view of a strainer. It is a XVI arrow line view of the strainer of FIG. It is a XVII arrow directional view of the strainer of FIG. FIG. 6 is a cross-sectional view of the lower crankcase member of FIG. 5 taken along XVIII-XVIII. FIG. 6 is a cross-sectional view of the lower crankcase member of FIG. 5 taken along XVIII-XVIII. FIG. 6 is a XX-XX cross-sectional view of the lower crankcase member of FIG. 5. FIG. 6 is an XXI-XXI cross-sectional view of the lower crankcase member of FIG. 5. FIG. 6 is a XXII-XXII cross-sectional view of the lower crankcase member of FIG. 5. FIG. 3 is a cross-sectional view of the oil pump and the scavenging pump taken along line XXIII-XXIII in FIG. It is a section of a cassette type mission, and is a view seen from the front. It is a left view of the crankcase of FIG. It is a piping perspective schematic diagram showing the flow of oil of the whole engine.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crankcase 2 Upper crankcase member 3 Lower crankcase member 5 Cylinder 7 Crankshaft 10 Crank chamber 10L Left crank chamber 10R Right crank chamber 11 Mission chamber (oil storage part component)
12 Clutch chamber (oil reservoir component)
20 Oil pan mounting portion 20a Oil pan mounting surface 23 Oil pan 23a Oil pan mating surface 24 Common pump shaft 29 Bulkhead 30L Left side wall of the crank chamber 30R Right side wall of the crank chamber 40a, 40b Partition wall 41 Mission mounting wall 42 Communication hole 50 Oil pump for feed 51 Scavenging pump (oil pump for recovery)
53 Left oil discharge port 54 Right oil discharge port 55 Oil recovery passage 56 Space for communicating oil recovery chamber 57 Peripheral wall 57a of space 56 Mounting surface 58 Gasket 60 Oil recovery chamber 61 Perimeter wall of oil recovery chamber 61a Matching surface 62 Oil suction Chamber (oil storage part component)
65 strainer 77 passage formation groove 78 bottom plate 80 side wall of passage formation groove 83 support seat of mounting surface complement member 84 adjustment hole 88 clutch cover 89 oil inspection window 92 main gallery 95 mounting surface complement member 96 mounting surface complement member support seat

Claims (6)

In a parallel multi-cylinder engine that includes a plurality of cylinders in parallel and that has an oil pan attached to an oil pan attachment portion formed on the lower surface of the crankcase,
An oil discharge port is formed on the bottom surface of each crank chamber divided for each cylinder,
An oil recovery chamber that communicates with a suction portion of a scavenging pump that pumps oil to an oil reservoir isolated from the crank chamber is provided in the oil pan below the bottom wall of the crank chamber ,
The oil discharge port communicates with the oil recovery chamber,
At least a part of each oil discharge port communicates with the oil recovery chamber via an oil recovery passage formed in the bottom wall of the crank chamber,
The oil collecting passage is composed of a passage-forming groove having an open lower end formed on a bottom wall of the crank chamber and a bottom plate that closes the lower end of the passage-forming groove. engine. The parallel multi-cylinder engine according to claim 1, wherein a strainer is accommodated in the oil recovery chamber. An oil piping space is formed in the oil pan mounting portion, the oil recovery passage is formed in the oil piping space, and an oil supply pipe for supplying oil to each lubrication point of the engine is disposed. The parallel multi-cylinder engine according to claim 1 or 2 . The lower part of the transmission chamber in the crankcase is the oil reservoir,
An oil suction chamber isolated from the oil recovery chamber is formed below the bottom wall of the crank chamber,
The oil suction chamber communicates with an oil pump suction portion for supplying oil to each lubrication point of the engine and also communicates with the oil storage portion . parallel multi-cylinder engine according to one. The scavenging pump and the oil pump are disposed in the mission chamber,
5. The parallel multi-cylinder engine according to claim 4 , wherein a discharge part of the oil pump communicates with a main gallery via the oil supply pipe disposed in a piping space of the oil pan mounting part. . An oil recovery chamber mounting surface corresponding to the mating surface at the upper end of the peripheral wall of the oil recovery chamber is formed in the oil pan mounting portion on the lower surface of the crankcase, and the portion of the mounting surface that communicates with the passage forming groove Open the
The parallel multi-cylinder engine according to any one of claims 1 to 5 , wherein a mounting surface complementary member that is substantially flush with the mounting surface for the oil recovery chamber is attached to the opening.

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