JP6977433B2 - Internal combustion engine - Google Patents

Description

The present invention relates to an internal combustion engine.

A feed pump that pumps lubricating oil to parts related to the crankshaft, the transmission chamber and clutch chamber, and lubricated parts such as the cylinder head side, and a scavenging pump that scrapes the lubricating oil in the crank chamber to the transmission chamber. Internal combustion engines equipped with are known.

In this conventional internal combustion engine, the feed pump is housed in the left crankcase half body and the scavenging pump is housed in the right crankcase half body (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2016-186252

In a conventional internal combustion engine, an oil passage through which the lubricating oil discharged from the feed pump passes and an oil passage through which the lubricating oil sucked into the scavenging pump passes are partitioned by separate walls. That is, a conventional internal combustion engine has a separate wall that separates an oil passage through which the lubricating oil discharged from the feed pump passes, and a wall that separates an oil passage through which the lubricating oil sucked into the scavenging pump passes. rice field. These multiple walls prevented the weight reduction of the internal combustion engine.

Therefore, the present invention includes an oil passage through which the lubricating oil discharged from the feed pump passes and an oil passage through which the lubricating oil sucked into the scavenging pump passes, while reducing the weight of the wall separating these, and thus reducing the overall weight. It is an object of the present invention to provide a viable internal combustion engine.

In order to solve the above problems, the internal combustion engine according to the present invention includes a crank case for partitioning a crank chamber, an oil storage unit provided at the bottom of the crank case for storing lubricating oil, and a cylinder combined with the crank case. When the is integral to the crankcase, a transmission case defining a transmission chamber, a feed pump for pumping the lubricating oil to be lubricated portion, the lubricating oil is pumped from the oil reservoir of the cylinder oil An oil supply passage that includes an outward route to feed into the passage and discharges the lubricating oil from the feed pump, and a recovery pump that discharges the lubricating oil accumulated in the crank chamber to the discharge oil passage leading to the transmission chamber. A guide oil passage that guides the lubricating oil accumulated in the crank chamber to the recovery pump, a partition wall that separates the oil supply passage and the guide oil passage by a pair of front and back wall surfaces, and a rotation center in the width direction of the crank case. The crankshaft and the transmission case are arranged in the front-rear direction, and the crankcase and the transmission case are the rotation centers of the crankshaft. The feed pump, the recovery pump, the oil supply passage, the guide oil passage, and the partition wall can be divided into a pair of halves by a connecting surface orthogonal to the line, and the partition is provided on one of the halves. One of the half bodies is opened in the opposite direction in the direction of the rotation center line of the crankshaft, and has a pair of pump accommodating portions accommodating each of the feed pump and the recovery pump .

According to the present invention, while providing an oil passage through which the lubricating oil discharged from the feed pump passes and an oil passage through which the lubricating oil sucked into the scavenging pump passes, the wall separating these is made lighter, and thus the overall weight is made lighter. It is possible to provide an internal combustion engine that can be converted.

The left side view which shows an example of the motorcycle to which the internal combustion engine which concerns on embodiment of this invention is applied. The front view which shows the internal combustion engine which concerns on embodiment of this invention. The left side view which shows the internal combustion engine which concerns on embodiment of this invention. The schematic system diagram of the lubrication structure of the internal combustion engine which concerns on embodiment of this invention. The schematic perspective view of the lubrication system of the internal combustion engine which concerns on embodiment of this invention. FIG. 2 is a cross-sectional view of an internal combustion engine according to an embodiment of the present invention in the VI-VI line of FIG. FIG. 2 is a sectional view of an internal combustion engine according to an embodiment of the present invention in the line VII-VII of FIG. FIG. 3 is a sectional view of an internal combustion engine according to an embodiment of the present invention in the line VIII-VIII of FIG. The schematic diagram schematically showing the relationship between the piston and the piston jet of the internal combustion engine which concerns on embodiment of this invention. The schematic which shows typically the relationship between the piston of the internal combustion engine which concerns on embodiment of this invention, and the other example of a piston jet. The partially enlarged view of the right side surface of the right side case half body of the internal combustion engine which concerns on this embodiment. The perspective view of a part of the clutch chamber of the internal combustion engine which concerns on this embodiment. FIG. 11 is a cross-sectional view of a blow-by gas inlet of an internal combustion engine according to the present embodiment on the XIII-XIII line of FIG. FIG. 6 is an enlarged view of a part of FIG. 6 showing a breather chamber of an internal combustion engine according to the present embodiment. FIG. 7 is an enlarged view of a part of FIG. 7 showing a breather chamber of an internal combustion engine according to the present embodiment.

An embodiment of the internal combustion engine according to the present invention will be described with reference to FIGS. 1 to 15. In the plurality of drawings, the same or corresponding configurations are designated by the same reference numerals.

FIG. 1 is a left side view showing an example of a motorcycle to which an internal combustion engine according to an embodiment of the present invention is applied.

The front-rear, up-down, and left-right expressions in the present embodiment are based on the occupant of the motorcycle 1.

As shown in FIG. 1, the motorcycle 1 according to the present embodiment has a vehicle body frame 2 extending in the front-rear direction, a front wheel 5 arranged in front of the vehicle body frame 2, and a front wheel 5 arranged at the front end portion of the vehicle body frame 2. A steering mechanism 6 that rotatably supports the rear wheels 7, a rear wheel 7 that is arranged behind the vehicle body frame 2, a swing arm 8 that is arranged at the rear of the vehicle body frame 2 and rotatably supports the rear wheels 7, and a vehicle body frame 2. It is equipped with an internal combustion engine 11 (hereinafter, simply referred to as "engine 11") to be mounted. Further, the motorcycle 1 is a fuel tank 12 arranged above the front half of the body frame 2 to store fuel supplied to the engine 11, and a seat arranged above the rear half of the body frame 2 to seat passengers. A vehicle body cover 15 that covers a part of the vehicle body frame 2 is provided with the vehicle body cover 13.

The body frame 2 is a so-called cradle type. The body frame 2 includes a plurality of steel hollow tubes that are integrally combined. That is, the vehicle body frame 2 includes a head pipe 21, a main tube 22, a down tube 23, a pair of left and right seat rails 25, and a pair of left and right seat pillars 26.

The head pipe 21 is arranged in the upper part of the front end of the vehicle body frame 2. The head pipe 21 supports the steering mechanism 6 so as to steer the vehicle in the left-right direction.

The main tube 22 extends obliquely backward and downward from the front end portion connected to the upper rear surface of the head pipe 21, is curved in the middle, and hangs downward.

The down tube 23 extends rearward while inclining further downward than the main tube 22 from the front end portion connected to the lower rear surface of the head pipe 21, and curves in the middle toward the rear.

The pair of left and right seat rails 25 branch from the front end portion connected to the curved portion of the main tube 22, and extend diagonally backward and upward with a gentle inclination.

The pair of left and right seat pillars 26 branch from the front end connected to the lower end of the main tube 22, extend diagonally backward and upward, and join the intermediate portion of the length of the seat rail 25 to join the seat rail 25. Supports.

The steering mechanism 6 has a suspension mechanism (not shown) built in, a pair of left and right front forks 27 that rotatably support the front wheels 5, a front fender 28 that covers above the front wheels 5, and the top of the front forks 27. It is provided with a handle 29 to be fixed.

The front wheel 5 is sandwiched between the left and right front forks 27 and rotates about an axle erected at the lower ends of the left and right front forks 27.

The swing arm 8 is supported by a pivot shaft (not shown) provided on the vehicle body frame 2 and can swing in the vertical direction. An axle that rotatably supports the rear wheel 7 is provided at the rear end of the swing arm 8. The rear cushion unit 31 is erected between the vehicle body frame 2 and the swing arm 8. The rear cushion unit 31 buffers the force transmitted from the rear wheel 7 to the vehicle body frame 2.

The drive chain 32 transmits the output of the engine 11 to the rear wheels 7 to rotate the rear wheels 7.

The engine 11 is arranged between the main tube 22 and the down tube 23, and is fixed to the main tube 22 and the down tube 23.

An oil cooler 33 for cooling the lubricating oil for lubricating and cooling each part of the engine 11 is provided diagonally forward and upward above the engine 11. It is preferable that the oil cooler 33 is arranged so as to avoid the position where the front fender 28 and the front wheel 5 face the front so as to be easily exposed to the traveling wind of the motorcycle 1.

The fuel tank 12 is exclusively supported by the main tube 22. The fuel tank 12 swells from immediately after the head pipe 21 to the vicinity of the front end portion of the seat rail 25.

The seat 13 is provided behind the fuel tank 12. The seat 13 straddles the left and right seat rails 25 and reaches the rear end portion of the seat rail 25.

The vehicle body cover 15 includes a front cover 35 made of synthetic resin, a pair of left and right side covers 36, and a rear cover 37, respectively.

The front cover 35 is provided in front of the head pipe 21. The front cover 35 is fixed to the steering mechanism 6.

The side cover 36 is connected to the lower rear portion of the fuel tank 12, extends in an inverted triangle over the main tube 22, the seat rail 25, and the seat pillar 26, and sandwiches them from the left and right.

The rear cover 37 is connected to the lower ends of the left and right side surfaces of the latter half of the seat 13 and extends rearward, and extends to the rear of the seat 13 to join.

Next, the engine 11 according to the present embodiment will be described in detail.

FIG. 2 is a front view showing an internal combustion engine according to an embodiment of the present invention.

FIG. 3 is a left side view showing an internal combustion engine according to an embodiment of the present invention.

As shown in FIGS. 2 and 3, the engine 11 according to the present embodiment is, for example, a 50 cc class or 250 cc class small displacement internal combustion engine. The engine 11 is a 4-cycle single-cylinder internal combustion engine. The engine 11 includes a crankcase 41, a cylinder 42 combined with the crankcase 41, a cylinder head 43 combined with the cylinder 42, and a head cover 44 combined with the cylinder head 43.

The crankcase 41 is made of an aluminum alloy. The crankcase 41 is arranged in the lower half of the engine 11. The crankcase 41 includes an integrated transmission case 45.

The crankcase 41 includes a left side case half body 51 and a right side case half body 52. The crankcase 41 can be divided into left and right. The left and right case halves 51 and 52 are combined by a coupling surface 41a substantially orthogonal to the rotation center line of the crankshaft 47. In other words, the left and right case halves 51 and 52 are integrated by the connecting surface 41a. The crankcase 41 has a pair of left and right case halves 51, 52 combined at a coupling surface 41a substantially orthogonal to the rotation centerline of the crankshaft 47.

Further, the crankcase 41 includes a left side case cover 53 provided on the left side of the left side case half body 51 and a right side case cover 54 provided on the right side of the right side case half body 52. The left case cover 53 is a magneto cover, and the right case cover 54 is a clutch cover.

The cylinder 42 is coupled to the front portion of the upper surface of the crankcase 41 in a forward leaning posture in which the center line of the cylinder bore 48, that is, the moving direction of the piston 49 is slightly tilted forward.

The cylinder head 43 is coupled to the top of the cylinder 42 to block the cylinder 42. An outlet flange 43a of an exhaust port (not shown) is provided on the front surface of the cylinder head 43. An inlet flange 43b for an intake port (not shown) is provided on the back surface of the cylinder head 43.

The head cover 44 is coupled to the top of the cylinder head 43 to close the cylinder head 43.

An oil cooler 33 is connected to the engine 11 via oil hoses 55 and 56.

The oil cooler 33 includes a fan 57 that generates cooling air. The oil cooler 33 cools the lubricating oil flowing from the oil hose 55 by the wind of the fan 57 or the traveling wind of the motorcycle 1, and returns the cooled lubricating oil from the oil hose 56 to the engine 11.

The oil hoses 55 and 56 circulate lubricating oil between the engine 11 and the oil cooler 33.

The oil hose 55 arranged below sends oil from the engine 11 to the oil cooler 33. The oil hose 55 extends from the corner of the front wall and the right side wall of the cylinder 42, bypasses the front of the cylinder 42, and extends to the oil cooler 33. The oil hose 55 is connected to the bottom of the oil cooler 33.

The oil hose 56 (first return oil passage) arranged above returns the lubricating oil from the oil cooler 33 to the engine 11. The oil hose 56 extends from the corners of the front wall and the left side wall of the cylinder 42 to the oil cooler 33. The oil hose 56 is connected to the top of the oil cooler 33.

FIG. 4 is a schematic system diagram of the lubrication structure of the internal combustion engine according to the embodiment of the present invention.

As shown in FIG. 4, the engine 11 according to the present embodiment includes an oil passage 59 provided in a crankcase 41, a cylinder 42, and a cylinder head 43 as an oil passage on the internal combustion engine side for circulating lubricating oil. .. In other words, the engine 11 is an oil-cooled type.

Further, the engine 11 is provided with an oil pan 61 as an oil storage portion provided at the bottom of the crankcase 41 to store lubricating oil.

The engine 11 supplies the lubricating oil stored in the oil pan 61 to the lubricated portion including the crankshaft 47, the piston 49, the valve mechanism 62, the counter shaft 65 of the transmission 63, and the drive shaft 66 of the transmission 63. Then lubricate and cool them.

The crankcase 41 has a crank chamber 67 in which the crankshaft 47 is housed, and a transmission room 68 in which the transmission 63 is housed. The transmission chamber 68 is divided into a transmission case 45. In other words, the crankcase 41 partitions the crank chamber 67, and the transmission case 45 partitions the transmission chamber 68. The crank chamber 67 and the transmission chamber 68 are arranged in the front-rear direction of the engine 11. The crank chamber 67 is arranged in the front half of the crankcase 41, and the transmission chamber 68 is arranged in the second half of the crankcase 41.

The crankshaft 47 is rotatably supported in the crank chamber 67. The crankshaft 47 points the rotation center line in the width direction of the crankcase 41, that is, in the width direction of the engine 11. The piston 49 is housed in the cylinder bore 48 of the cylinder 42 so as to be reciprocating. The piston 49 reciprocates in the cylinder 42. The valve operating mechanism 62 is housed in a valve operating chamber (not shown) of the cylinder head 43. The counter shaft 65 and the drive shaft 66 are housed in the transmission chamber 68.

The oil cooler 33 is arranged above the highest point of the oil passage 59. The oil cooler 33 cools the lubricating oil (not shown) flowing through the oil passage 59. The lubrication structure of the internal combustion engine includes an oil passage 59 of the engine 11 and an oil cooler 33.

The oil passage 59a of the crankcase 41 includes an outward route for pumping lubricating oil from the oil pan 61 and sending it to the oil passage 59b of the cylinder 42, and a return route for returning the lubricating oil from the oil passage 59b of the cylinder 42 to the oil pan 61. I'm out.

The outward path of the oil passage 59a of the crankcase 41 is a crankshaft lubricating oil passage 75 that guides lubricating oil from the oil pan 61 to the shaft end 47a of the crankshaft 47, and a piston that sprays the lubricating oil guided from the oil pan 61 onto the piston 49. It is provided with a cooling oil passage 76.

The lubricating oil supplied to the shaft end 47a of the crankshaft 47 lubricates the bearing that rotatably supports the crankshaft 47 (not shown) and the connecting rod that connects the crankshaft 47 and the piston 49 (not shown). , Dripping into the crank chamber 67.

The lubricating oil sprayed on the piston 49 drips into the crank chamber 67.

The oil passage 59b of the cylinder 42 has a first oil passage 81 directly connected to the cylinder head 43, a second oil passage 82 connected to the oil cooler 33 via the oil hose 55, and an oil cooler 33 via the oil hose 56. A third oil passage 83, which is connected to the cylinder head 43 and is connected to the cylinder head 43, is included.

The oil hose 56 is a first return oil passage for returning the lubricating oil cooled by the oil cooler 33 to the oil passage 59b in the cylinder 42.

The oil passage 59c of the cylinder head 43 is an exhaust port with the fourth oil passage 84 that guides the lubricating oil flowing from the first oil passage 81 of the cylinder 42 to the valve mechanism 62 and the lubricating oil flowing from the third oil passage 83 of the cylinder 42. It includes a fifth oil passage 85, which cools the periphery of the 69.

The oil passage 59b of the cylinder 42 includes a sixth oil passage 86 that circulates lubricating oil flowing from the fifth oil passage 85 of the cylinder head 43 around the combustion chamber 70, and lubricating oil from the sixth oil passage 86 into the crankcase 41. It is equipped with a seventh oil passage 87, which returns the oil.

The seventh oil passage 87 is a second return oil passage that returns from the oil cooler 33 and returns the lubricating oil that has cooled the cylinder 42 and the cylinder head 43 to the crankcase 41.

The return path portion of the oil passage 59a of the crankcase 41 includes a storage portion 89 for storing the lubricating oil flowing out from the seventh oil passage 87 of the cylinder 42, and an eighth oil passage 88 connected to the storage portion 89.

The storage unit 89 is open to the transmission chamber 68. Therefore, the lubricating oil of the storage unit 89 overflows from the storage unit 89 into the transmission chamber 68 while filling the storage unit 89 (solid line arrow OF in FIG. 4). The lubricating oil that overflows from the storage unit 89 into the transmission chamber 68 lubricates the transmission 63. The lubricating oil that lubricates the transmission 63 drips onto the oil pan 61.

The eighth oil passage 88 is a transmission lubricating oil passage for guiding lubricating oil from the storage portion 89 to at least one of the shaft end 65a of the counter shaft 65 and the shaft end 66a of the drive shaft 66. The eighth oil passage 88 according to the present embodiment has a first transmission lubricating oil passage 91 for guiding lubricating oil from the storage unit 89 to the shaft end 65a of the counter shaft 65, and the storage unit 89 to the shaft end 66a of the drive shaft 66. It includes a second transmission lubricating oil passage 92 for guiding lubricating oil.

Further, the engine 11 includes a scavenging pump 95 as a recovery pump for pumping the lubricating oil accumulated at the bottom of the crank chamber 67 to the transmission chamber 68. At the bottom of the crank chamber 67, lubricating oil that lubricates the crankshaft 47 and drips into the crank chamber 67, and lubricating oil that cools the piston 49 and drips into the crank chamber 67 accumulates.

FIG. 5 is a schematic perspective view of the lubrication system of the internal combustion engine according to the embodiment of the present invention.

In addition to FIG. 4, as shown in FIG. 5, the engine 11 according to the present embodiment has an oil pump 96 that sucks lubricating oil from an oil pan 61 and a first that removes foreign matter from the lubricating oil sucked into the oil pump 96. It includes an oil filter 98 and a second oil filter 99 that removes foreign matter from the lubricating oil discharged from the oil pump 96. The oil pump 96 and the second oil filter 99 are provided in the outward path portion of the oil passage 59a of the crankcase 41.

The oil passage 59a of the crankcase 41 is provided in each of the left side case half body 51 and the right side case half body 52, and is connected by a connecting surface 41a of the crankcase 41.

The oil pump 96 is a feed pump that pumps lubricating oil to the lubricated portion. The oil pump 96 is arranged below the crankshaft 47. The oil pump 96 is driven by an auxiliary drive gear (not shown) that is rotationally integrated with the crankshaft 47. The output of the oil pump 96 depends on the rotation speed of the crankshaft 47, that is, the rotation speed of the engine 11. That is, the oil pump 96 discharges a larger amount of lubricating oil as the rotation speed of the engine 11 increases. By driving the oil pump 96, the lubricating oil in the oil pan 61 is sucked into the oil passage 59a of the crankcase 41. The oil pump 96 is connected to the second oil filter 99 via the pump discharge side oil passage 101. The pump discharge side oil passage 101 is an oil supply / supply passage where lubricating oil is discharged from the oil pump 96. The lubricating oil sucked into the oil passage 59a of the crankcase 41 passes through the second oil filter 99 to remove foreign matter.

The lubricating oil that has passed through the second oil filter 99 reaches the shaft end 47a of the crankshaft 47 via the crankshaft lubricating oil passage 75. Further, the lubricating oil that has passed through the second oil filter 99 is sprayed onto the piston 49 via the piston cooling oil passage 76.

Further, the lubricating oil that has passed through the second oil filter 99 is cooled by the oil cooler 33 via the second oil passage 82 of the cylinder 42 and the oil hose 55. The lubricating oil cooled by the oil cooler 33 reaches the fifth oil passage 85 of the cylinder head 43 via the oil hose 56 and the third oil passage 83. The lubricating oil that has passed through the fifth oil passage 85 and cooled the exhaust port 69 flows into the sixth oil passage 86 and cools the combustion chamber 70. The lubricating oil that has passed through the sixth oil passage 86 and cooled the combustion chamber 70 is returned from the seventh oil passage 87 to the crankcase 41.

Further, the lubricating oil branched at the cylinder 42 and flowing into the first oil passage 81 climbs upward on the cylinder 42 to reach the fourth oil passage 84 of the cylinder head 43, and lubricates the valve operating mechanism 62.

Then, the lubricating oil returned from the seventh oil passage 87 to the crankcase 41 is stored in the storage unit 89. A part of the lubricating oil stored in the storage unit 89 flows out from the storage unit 89 to the eighth oil passage 88. Of the eighth oil passage 88, the lubricating oil passing through the first transmission lubricating oil passage 91 reaches the shaft end 65a of the counter shaft 65. The lubricating oil that has reached the shaft end 65a of the counter shaft 65 flows into a hole extending along the axis of the counter shaft 65 and lubricates the counter gear 105 rotatably supported by the counter shaft 65. The lubricating oil that lubricated the counter gear 105 drops in the transmission chamber 68 and returns to the oil pan 61.

On the other hand, the lubricating oil passing through the second transmission lubricating oil passage 92 in the eighth oil passage 88 reaches the shaft end 66a of the drive shaft 66. The lubricating oil that reaches the shaft end 66a of the drive shaft 66 flows into a hole extending along the axis of the drive shaft 66 and lubricates the drive gear 106 rotatably supported by the drive shaft 66. The lubricating oil that lubricates the drive gear 106 drops in the transmission chamber 68 and returns to the oil pan 61.

Further, a part of the lubricating oil stored in the storage unit 89 overflows from the storage unit 89 and drops directly into the transmission chamber 68. The lubricating oil dropped in the transmission chamber 68 is applied to the transmission, lubricates the counter gear 105 and the drive gear 106, drops in the transmission chamber 68, and returns to the oil pan 61.

The oil passage 59 of the engine 11 may include a second storage portion 108 provided in the middle of at least one of the oil hose 56, the seventh oil passage 87, and the eighth oil passage 88. For example, the oil passage 59 according to the present embodiment includes a second storage portion 108 provided in the middle of the seventh oil passage 87. The second storage unit 108 is connected to a ninth oil passage 111 as a magneto cooling passage for guiding lubricating oil from the second storage unit 108 to the magneto 109.

The storage portion 89 of the oil passage 59 is arranged below the oil cooler 33. Therefore, the lubricating oil flowing out of the oil cooler 33 flows down to the storage unit 89 via the oil hose 56 and the oil passage 59b of the cylinder 42. In other words, the lubricating oil flowing out of the oil cooler 33 reaches the storage portion 89 by the head of the top of the oil cooler 33 and the storage portion 89. That is, the oil pump 96 only needs to be able to lift the lubricating oil to the top of the oil cooler 33.

Further, the shaft end 65a of the counter shaft 65 and the shaft end 66a of the drive shaft 66 connected to the eighth oil passage 88 are arranged below the storage portion 89. That is, in the oil passage 59 of the engine 11 according to the present embodiment, the shaft end 65a of the counter shaft 65 connected to the first transmission lubricating oil passage 91 is arranged below the storage portion 89, and the second transmission lubricating oil is provided. The shaft end 66a of the drive shaft 66 connected to the road 92 is also arranged below the storage portion 89. Therefore, the lubricating oil flowing out from the storage unit 89 flows down to the shaft end 65a of the counter shaft 65 via the first transmission lubricating oil passage 91, and flows down to the shaft end 66a of the drive shaft 66 via the second transmission lubricating oil passage 92. run down. Since the storage unit 89 is released to the transmission chamber 68, the lubricating oil flowing out from the storage unit 89 reaches the shaft end 65a of the counter shaft 65 by the head of the storage unit 89 and the shaft end 65a of the counter shaft 65. The water head between the reservoir 89 and the shaft end 66a of the drive shaft 66 reaches the shaft end 66a of the drive shaft 66. That is, the discharge pressure of the oil pump 96 does not act on the shaft end 65a of the counter shaft 65 and the shaft end 66a of the drive shaft 66.

The storage unit 89 straddles a pair of left and right case halves 51 and 52, extends in a gutter shape over substantially the entire width, and is open to the transmission chamber 68.

The eighth oil passage 88 guides the lubricating oil from one end 89a in the width direction of the storage portion 89 to the shaft end 65a of the counter shaft 65, and from the other end 89b in the width direction of the storage portion 89 to the drive shaft 66. Guide the lubricating oil to the shaft end 66a. That is, in the eighth oil passage 88, the first transmission lubricating oil passage 91 guides the lubricating oil from the left end portion 89a of the storage portion 89 to the shaft end 65a of the counter shaft 65. The second transmission lubricating oil passage 92 of the eighth oil passage 88 guides the lubricating oil from the right end portion 89b of the storage portion 89 to the shaft end 66a of the drive shaft 66.

The eighth oil passage 88 is inclined downward substantially over the entire length. That is, the first transmission lubricating oil passage 91 is inclined downward over the entire length from the left end portion 89a of the storage portion 89 toward the shaft end 65a of the counter shaft 65. The second transmission lubricating oil passage 92 is inclined downward over the entire length from the right end portion 89b of the storage portion 89 toward the shaft end 66a of the drive shaft 66.

FIG. 6 is a cross-sectional view of an internal combustion engine according to an embodiment of the present invention in the VI-VI line of FIG.

FIG. 7 is a cross-sectional view of an internal combustion engine according to an embodiment of the present invention in the line VII-VII of FIG.

6 and 7 correspond to a cross-sectional view of the engine 11 on the coupling surface 41a of the crankcase 41. In other words, FIG. 6 is the right side case half body 52 seen from the joint surface 41a side, and FIG. 7 is the left side case half body 51 seen from the joint surface 41a side.

As shown in FIGS. 6 and 7, the crankcase 41 of the engine 11 according to the present embodiment straddles the lower part of the crankcase 67 and the lower part of the transmission chamber 68 to store the lubricating oil in the oil storage chamber 121. A first common partition wall 122 that separates the crankcase 67 and the transmission chamber 68, a second common partition wall 123 that separates the crankcase 67 and the oil storage chamber 121, and a transmission chamber 68 are provided. The discharge oil passage partition wall 126 facing the first common partition 122 and partitioning the discharge oil passage 125, and extending from the first common partition 122 to the oil pan 61, the lower portion of the oil pan 61 of the crankcase 67. A plate body portion 128 that prevents the movement of the lubricating oil between the and the lower portion of the transmission chamber 68 is provided.

Further, the crankcase 41 includes a breather chamber 129 that separates oil mist from blow-by gas. In other words, the crankcase 41 partitions the breather chamber 129 in addition to the crank chamber 67 and the transmission chamber 68. The breather chamber 129 is attached to the transmission chamber 68 and is arranged above the transmission chamber 68.

The crankcase 41, the transmission case 45, the oil pan 61, and the plate body portion 128 can be divided into a pair of case halves 51 and 52 at the coupling surface 41a orthogonal to the crankshaft 47.

The oil pan 61 is an oil storage unit integrated with the crankcase 41. The oil pan 61 partitions an oil storage chamber 121 for storing lubricating oil. The oil storage chamber 121 is connected to the transmission chamber 68, while being isolated from the crank chamber 67 by the second common partition wall 123.

The first common partition wall 122 is integrated with the crankcase 41. The first common partition wall 122 is shared by the crankcase 41 and the transmission case 45. In other words, one surface of the first common partition wall 122 occupies a part of the inner surface of the crank chamber 67, and the other surface of the first common partition wall 122 occupies a part of the inner surface of the transmission chamber 68. The first common partition wall 122 has a substantially uniform thickness (distance between one surface and the other surface). The first common partition wall 122 extends in an arc shape following the outer shape of the counterweight 47b of the crankshaft 47.

The second common partition wall 123 is integrated with the crankcase 41. It is shared by the crankcase 41 and the oil pan 61. In other words, one surface of the second common partition wall 123 occupies a part of the inner surface of the crank chamber 67, and the other surface of the second common partition wall 123 occupies a part of the inner surface of the oil storage chamber 121. The second common partition wall 123 has a substantially uniform thickness (distance between one surface and the other surface).

The scavenging pump 95 is provided at the confluence of the first common partition wall 122 and the second common partition wall 123, and on the right side case half body 52. The scavenging pump 95 is housed in a scavenging pump housing 131 provided at a confluence of the first common partition wall 122 and the second common partition wall 123.

The scavenging pump 95 is a so-called trochoidal pump. The scavenging pump 95 includes an outer rotor 95a and an inner rotor 95b. The scavenging pump 95 directs the rotation center lines of the outer rotor 95a and the inner rotor 95b in the width direction of the crankcase 41. In other words, the rotation center lines of the outer rotor 95a and the inner rotor 95b, that is, the rotation center lines of the scavenging pump 95 are arranged parallel to the rotation center line of the crankshaft 47.

The scavenging pump 95 is closer to the inner surface of the bottom wall 132 of the oil pan 61, that is, the bottom surface 61a of the oil pan 61 than the crank chamber 67. The portion 95c of the scavenging pump 95 closest to the bottom surface 61a of the oil pan 61 is closer to the bottom surface 61a of the oil pan 61 than the portion 67a of the crank chamber 67 closest to the bottom surface 61a of the oil pan 61.

The scavenging pump housing 131 includes a pump accommodating portion 131a provided on the right side case half body 52 for accommodating the scavenging pump 95, and a pump accommodating lid portion 131b provided on the left side case half body 51 for accommodating the pump accommodating portion 131a. , Includes. The scavenging pump housing 131 has a suction port 135 connected to the crank chamber 67 and a discharge port 136 connected to the transmission chamber 68. Both end faces of the scavenging pump 95 face both the suction port 135 and the discharge port 136. The scavenging pump 95 sucks the lubricating oil from both end faces and discharges the lubricating oil from both end faces. The suction port 135 causes the lubricating oil discharged from the end face of the scavenging pump 95 to flow out in the radial direction of the scavenging pump 95. That is, the scavenging pump 95 sucks the lubricating oil from the radial direction and discharges it in the radial direction.

There are a pair of suction ports 135. One suction port 135 is provided in the pump storage lid portion 131b of the left case half body 51. The other suction port 135 is provided in the pump accommodating portion 131a of the right case half body 52. There is a pair of discharge ports 136. One discharge port 136 is provided on the pump storage lid portion 131b of the left case half body 51. The other discharge port 136 is provided in the pump accommodating portion 131a of the right case half body 52.

The suction port 135 of the scavenging pump housing 131 is arranged at the rear end of the second common partition wall 123. The second common partition wall 123 is inclined downward toward the suction port 135 of the scavenging pump housing 131. In other words, one surface of the second common partition wall 123, that is, the surface on the crank chamber 67 side, is inclined downward toward the suction port 135 of the scavenging pump housing 131.

The discharge oil passage partition wall 126 faces the wall surface of the first common partition wall 122 on the transmission chamber 68 side, in other words, the inner wall surface of the transmission chamber 68. The discharge oil passage partition wall 126 extends from the scavenging pump housing 131 in the height direction of the transmission chamber 68. The discharge oil passage partition wall 126 reaches the inner surfaces of the left and right side walls of the transmission chamber 68 and extends to the full width of the transmission chamber 68. In other words, the discharge oil passage partition wall 126 reaches the inner surfaces of the left and right side walls of the crankcase 41 and extends to the full width of the crankcase 41. A discharge oil passage 125 is partitioned between the discharge oil passage partition wall 126 and the first common partition wall 122. The discharge oil passage 125 is open toward the upper side of the transmission chamber 68. That is, the discharge oil passage 125 is also an oil reservoir having the discharge oil passage partition wall 126 as a bank. The discharge oil passage 125 discharges lubricating oil from the scavenging pump 95 to the transmission chamber 68. The bottom of the discharge oil passage 125 is connected to the discharge port 136 of the scavenging pump 95. In other words, the scavenging pump 95 discharges the lubricating oil accumulated in the crank chamber 67 to the discharge oil passage 125 leading to the transmission chamber 68. The oil level OL of the lubricating oil stored in the oil pan 61 is slightly lower than the highest level of the discharge oil passage partition wall 126. The oil level OL does not touch the gear of the transmission 63 in the horizontal state.

The plate body portion 128 extends from the lower portion of the scavenging pump 95 toward the rear of the crankcase 41. The plate body portion 128 is located directly below the transmission chamber 68 and extends substantially in the front half of the depth (dimension in the front-rear direction) of the transmission chamber 68. One outer surface of the plate body 128 faces the transmission chamber 68, and the other outer surface of the plate 128 faces the bottom surface 61a of the oil pan 61.

The plate body portion 128 has a suction port 141 for sucking the lubricating oil from the oil pan 61, and an oil passage 142 on the upstream side of the filter connected to the suction port 141 to allow the lubricating oil to flow.

The oil passage 142 on the upstream side of the filter is connected to the first oil filter 98. The oil passage 142 on the upstream side of the filter guides the lubricating oil sucked from the suction port 141 to the first oil filter 98.

The first oil filter 98 is provided on the left side case half body 51. The first oil filter 98 is arranged in a filter accommodating portion 143 that is opened to the left side of the left case half body 51. The filter accommodating portion 143 is closed by the left case cover 53, that is, the magneto cover. The filter accommodating portion 143 is connected to the oil passage 142 on the upstream side of the filter. Further, the filter accommodating portion 143 is connected to the oil pump 96 via the filter downstream side oil passage 144 that crosses the left side case half body 51 and the right side case half body 52.

The plate body portion 128 is separated from the bottom wall 132 of the oil pan 61. In other words, the wall 146 of the plate body portion 128 that partitions the oil passage 142 on the upstream side of the filter and the bottom wall 132 of the oil pan 61 are separated from each other. The gap between the wall 146 that partitions the oil passage 142 on the upstream side of the filter and the bottom wall 132 of the oil pan 61 is a part of the oil storage chamber 121 that stores the lubricating oil. This gap, that is, the gap between the plate body portion 128 and the bottom wall 132 of the oil pan 61 is usually filled with lubricating oil. This gap is narrower in the vertical direction of the engine 11 than other parts of the oil storage chamber 121. Although it is a familiar expression, this gap is substantially lower in ceiling height than other parts of the oil storage chamber 121.

The plate body portion 128 is closer to the bottom surface 61a of the oil pan 61 than the discharge oil passage 125. The plate body portion 128 is closer to the bottom surface 61a of the oil pan 61 than the scavenging pump housing 131. The trailing edge of the other outer surface of the plate 128 is closest to the bottom wall 132 of the oil pan 61 compared to the rest of the plate 128. This part is the lowest part in the oil storage chamber 121.

The portion of the oil storage chamber 121 on the crankcase 67 side is slightly inclined backward from the front side to the rear side of the crankcase 41 with the gap portion between the plate body portion 128 and the bottom surface 61a of the oil pan 61 as a boundary. By the second common partition wall 123, the portion where the ceiling height is lowered in an arc shape from the front side to the rear side of the crankcase 41 along the scavenging pump housing 131, and the plate body portion 128 extending from the scavenging pump housing 131. It reaches the gap portion between the plate body portion 128 whose ceiling height is lowered stepwise and the bottom surface 61a of the oil pan 61. At the boundary between the second common partition wall 123 and the scavenging pump housing 131, the ceiling height is lowered in an arc shape by the wall surface defining the oil passage 144 on the downstream side of the filter.

In the portion of the oil storage chamber 121 on the transmission chamber 68 side, the wall surface corresponding to the ceiling of the plate body portion 128 faces above the transmission chamber 68 and is raised stepwise.

The plate body portion 128 reaches the inner surfaces of the left and right side walls of the oil storage chamber 121 and extends to the full width of the oil storage chamber 121. In other words, the plate body portion 128 reaches the inner surfaces of the left and right side walls of the crankcase 41 and extends substantially to the full width of the crankcase 41. The oil passage 142 on the upstream side of the filter also reaches the inner surfaces of the left and right side walls of the oil storage chamber 121 and extends to the full width of the oil storage chamber 121. In other words, the oil passage 142 on the upstream side of the filter reaches the inner surfaces of the left and right side walls of the crankcase 41 and extends substantially to the full width of the crankcase 41. The suction port 141 of the oil passage 142 on the upstream side of the filter is provided at the central portion in the width direction of the crankcase 41. That is, the suction port 141 straddles the connecting surface 41a between the left side case half body 51 and the right side case half body 52. The suction port 141 corresponds to the entrance of the entire oil passage 59, which sucks the lubricating oil from the oil storage chamber 121 into the oil passage 59. The suction port 141 faces the bottom surface 61a of the oil pan 61, that is, the inner surface of the bottom wall 132 of the oil pan 61. The suction port 141 is arranged at the rear end edge portion of the other outer surface of the plate body portion 128 facing the bottom surface 61a of the oil pan 61. The suction port 141 is provided at the center of the rear end edge portion of the other outer surface of the plate body portion 128, which is the portion closest to the bottom wall 132 of the oil pan 61 as compared with the other portions of the plate body portion 128. There is.

The lubricating oil stored in the oil storage chamber 121 causes liquid level sway (sloshing) due to acceleration and deceleration of the motorcycle 1 on which the engine 11 is mounted. When the motorcycle 1 accelerates, the lubricating oil moves to the rear of the engine 11, that is, to the transmission chamber 68 side, while when the motorcycle 1 decelerates, it moves to the front of the engine 11, that is, to the crank chamber 67 side. do. When the gear of the transmission 63 is immersed in the lubricating oil due to the liquid level fluctuation, the gear of the transmission 63 agitates the lubricating oil, which in turn becomes a resistance to the rotation of the gear. Further, if the suction port 141, which is the entrance of the oil passage 59, is exposed to the outside of the oil surface due to the liquid level fluctuation, the supply of the lubricating oil to the lubricated portion may be temporarily cut off.

Therefore, the engine 11 according to the present embodiment includes a plate body portion 128 in the lubricating oil of the oil storage chamber 121. The gap between the plate body portion 128 and the bottom wall 132 of the oil pan 61 is in the oil storage chamber 121, and the portion of the oil storage chamber 121 directly below the crank chamber 67 and the portion directly below the transmission chamber 68 are formed. While connecting, the ceiling height is lower than both parts, and the cross-sectional area of the flow path through which the lubricating oil flows is narrowed (squeezed). Therefore, the flow of the lubricating oil in the oil storage chamber 121 caused by the acceleration or deceleration of the motorcycle 1, particularly the traffic of the lubricating oil between the portion directly under the crank chamber 67 and the portion directly under the transmission chamber 68. It is suppressed by the gap between the plate body portion 128 and the bottom wall 132 of the oil pan 61. The effect of suppressing the flow of lubricating oil between the portion directly below the crank chamber 67 and the portion directly below the transmission chamber 68 delays and suppresses the liquid level fluctuation in the oil storage chamber 121.

FIG. 8 is a cross-sectional view of an internal combustion engine according to an embodiment of the present invention in the line VIII-VIII of FIG.

Note that FIG. 8 passes through the rotation center line of the scavenging pump 95.

As shown in FIG. 8, the crankcase 41 of the engine 11 according to the present embodiment includes an oil block 147 provided on the right side surface of the right side case half body 52.

The oil block 147 cooperates with the right case half body 52 to partition the oil passage 59a of the crankcase 41. The oil block 147 is covered by the right case cover 54.

The oil pump 96 and the scavenging pump 95 are provided on one of the case halves 51 and 52, and in the present embodiment, on the right side case halves 52. The right case half body 52 is opened in the opposite direction in the direction of the rotation center line of the crankshaft 47, and has a pair of pump accommodating portions 131a and 151a accommodating the oil pump 96 and the scavenging pump 95, respectively.

The oil pump 96 is provided at the confluence of the first common partition wall 122 and the second common partition wall 123, and on the right side case half body 52. The oil pump 96 is housed in an oil pump housing 151 provided at a confluence of the first common partition wall 122 and the second common partition wall 123.

The oil pump 96 is a so-called trochoid type pump, similar to the scavenging pump 95. The oil pump 96 includes an outer rotor 96a and an inner rotor 96b. The oil pump 96 directs the rotation center lines of the outer rotor 96a and the inner rotor 96b in the width direction of the crankcase 41. In other words, the rotation center lines of the outer rotor 96a and the inner rotor 96b, that is, the rotation center lines of the oil pump 96 are arranged parallel to the rotation center line of the crankshaft 47. The rotary shaft core 96c of the oil pump 96 and the rotary shaft core 95d of the scavenging pump 95 are coaxially integrated. One of the shaft ends of the integrated rotary shaft cores 96c and 95d protrudes to the right side of the right side surface of the right case half body 52 and to the right side of the right side surface of the oil block 147. At one of the shaft ends of the rotating shaft cores 96c and 95d, an auxiliary driven gear 152 that is meshed with the auxiliary drive gear that is integrally rotated with the crankshaft 47 is provided.

The oil pump housing 151 includes a pump accommodating portion 151a provided on the right side case half body 52 for accommodating the oil pump 96, and a pump accommodating lid portion 151b provided on the oil block 147 for accommodating the pump accommodating portion 151a. There is. The oil pump housing 151 has a suction port 155 connected to the first oil filter 98 and a discharge port 156 connected to the second oil filter 99.

There are a pair of suction ports 155 of the oil pump housing 151. One suction port 155 is provided in the pump storage lid portion 151b of the oil block 147. The other suction port 155 is provided in the pump accommodating portion 151a of the right case half body 52. There is a pair of discharge ports 156. One discharge port 156 is provided on the pump storage lid portion 151b of the oil block 147. The other discharge port 156 is provided in the pump accommodating portion 151a of the right case half body 52. Both end faces of the oil pump 96 face both the suction port 155 and the discharge port 156. The oil pump 96 sucks the lubricating oil from both end faces and discharges the lubricating oil from both end faces. The suction port 155 causes the lubricating oil discharged from the end face of the oil pump 96 to flow out in the radial direction of the oil pump 96. That is, the oil pump 96 sucks the lubricating oil from the radial direction and discharges it in the radial direction.

The suction port 135 of the scavenging pump housing 131 is arranged at the center of the rear end of the crank chamber 67. In other words, the crank chamber 67 has a suction port 135 for sucking lubricating oil from the guide oil passage 158 into the scavenging pump 95.

The bottom of the crank chamber 67 is a guide oil passage 158 that guides the lubricating oil accumulated in the crank chamber 67 to the scavenging pump 95. The guide oil passage 158 is inclined downward toward the suction port 135 of the scavenging pump 95, and narrows the width (dimension in the width direction of the crankcase) toward the suction port 135 of the scavenging pump 95.

The crankcase 41 is provided with a partition wall 159 that separates the pump discharge side oil passage 101 and the guide oil passage 158 by a pair of front and back wall surfaces 159a and 159b. The partition wall 159 is provided on the right side case half body 52. That is, in the crank case 41, the pump discharge side oil passage 101 through which the lubricating oil discharged from the oil pump 96 flows and the guide oil passage 158 for guiding the lubricating oil to the scavenging pump 95 are arranged side by side on the front and back sides of the partition wall 159. It is partitioned.

The partition wall 159 hangs on the projection region PA of the oil pump 96 toward the crank chamber 67 side, bends toward the transmission chamber 68 side as it approaches the scavenging pump 95, and reaches the suction port 135. The partition wall 159 has a substantially uniform plate thickness.

The wall surface 159a on the crank chamber 67 side is a part of the inner wall surface of the crank chamber 67 that partitions the guide oil passage 158. The wall surface 159a approaches the oil pump 96 from a direction substantially orthogonal to the rotation center line of the oil pump 96, changes its direction while drawing an arc toward the coupling surface 41a of the crankcase 41, and escapes from the projection region PA. As it approaches the coupling surface 41a, it approaches the rear end edge of the crankcase 67 while drawing an arc, and reaches the suction port 135a connected to the end surface of the scavenging pump 95 on the side closer to the oil pump 96 among the pair of suction ports 135.

The wall surface 159b is a part of the wall surface of the right side case half body 52 that partitions the pump discharge side oil passage 101. The wall surface 159b is separated from the suction port 155a connected to the end surface of the oil pump 96 on the side closer to the scavenging pump 95 of the pair of suction ports 155 in the radial direction of the oil pump 96 while drawing an arc, and the connecting surface of the crankcase 41. It extends in a direction away from 41a and enters the projection region PA, and as it further moves away from the coupling surface 41a, it turns in the radial direction of the oil pump 96 while drawing an arc and separates from the oil pump 96.

FIG. 9 is a schematic view schematically showing the relationship between the piston and the piston jet of the internal combustion engine according to the embodiment of the present invention.

In addition to FIGS. 4 to 7, as shown in FIG. 9, the engine 11 according to the present embodiment includes a piston jet 171 as an oil injection unit for injecting lubricating oil to the piston 49.

The piston 49 includes a pair of pin bosses 173, a pair of skirts 174, and a pair of sidewalls 175 that connect the pin bosses 173 and the skirt 174. Further, the piston 49 has a piston inner region 176 surrounded by an inner side surface 173a of the pair of pin bosses 173, an inner side surface 174a of the pair of skirts 174, and an inner side surface 175a of the pair of sidewalls 175.

The oil passage 59a of the crankcase 41 is connected to the piston jet 171.

The piston jet 171 has a pair of oil injection holes 178 for injecting lubricating oil into each of the pair of pin bosses 173. The pair of oil injection holes 178 are arranged in a region symmetrical with respect to the center line of the cylinder bore 48 and sandwiched between the pair of pin bosses 173. The pair of oil injection holes 178 are machined holes directly drilled in the crankcase 41.

The piston jet 171 sprays lubricating oil on the pin boss 173 when the piston 49 is at top dead center TDC, and sprays lubricating oil on the piston inner region 176 when the piston 49 is at bottom dead center BDC. More specifically, one oil injection hole 178 of the piston jet 171 sprays lubricating oil on one pin boss 173 when the piston 49 is at top dead center TDC, and the piston when the piston 49 is at bottom dead center BDC. Lubricating oil is sprayed on the inner region 176. The other oil injection hole 178 of the piston jet 171 sprays lubricating oil on the other pin boss 173 when the piston 49 is at top dead center TDC and into the piston inner region 176 when the piston 49 is at bottom dead center BDC. Spray the lubricating oil. That is, the piston jet 171 can spray the lubricating oil on either one of the pair of pin bosses 173 and the piston inner region 176 at one oil injection hole 178.

The lubricating oil injection direction J of the piston jet 171 points toward the piston inner region 176 rather than the pair of skirts 174.

Further, the injection direction J of the lubricating oil of the piston jet 171 is sandwiched between the inner edge 181t of the pin boss 173 of the piston 49 at the top dead center TDC and the inner edge 181b of the pin boss 173 of the piston 49 at the bottom dead center BDC. It is included in the injection region 182. In this injection direction J, when the piston 49 is at the top dead center TDC, the lubricating oil is sprayed on the region outside the inner edge 181t of the pin boss 173, that is, the outside of the piston inner region 176, and the piston 49 is at the bottom dead center BDC. At the time of, the lubricating oil is sprayed on the region inside the inner edge 181b of the pin boss 173, that is, the piston inner region 176. In such an injection direction J, when the piston 49 reciprocates between the top dead center TDC and the bottom dead center BDC, the lubricating oil is alternately wiped on the pin boss 173 and the piston inner region 176, and both of them are sprayed. Cool and lubricate the area and the area between both areas.

The extension of the straight line connecting the inner edge 181b of the pin boss 173 of the piston 49 at the bottom dead center BDC and the oil injection hole 178 reaches the outer edge 183 of the pin boss 173 of the piston 49 at the top dead center TDC. , Or more preferably to the outside. Further, the injection angle of the lubricating oil of the piston jet 171 may extend to the outside of the injection region 182.

Further, the injection angle of the lubricating oil of the piston jet 171 should be as narrow as possible. The narrower the injection angle, the more concentrated the lubricating oil can be sprayed on the target area.

FIG. 10 is a schematic diagram schematically showing the relationship between the piston of the internal combustion engine according to the embodiment of the present invention and another example of the piston jet.

In the piston jet 171A of another example, the same reference numerals are given to the same configurations as the piston jet 171 shown in FIG. 9, and duplicate description will be omitted.

As shown in FIG. 10, the piston jet 171A of the engine 11 according to the present embodiment has a pair of oil injection holes 178A for injecting lubricating oil into each of the pair of pin bosses 173. The pair of oil injection holes 178A are symmetrical with respect to the center line of the cylinder bore 48 and are arranged outside the region sandwiched between the pair of pin bosses 173.

The piston jet 171A sprays lubricating oil on the pin boss 173 when the piston 49 is at bottom dead center BDC, and sprays lubricating oil on the piston inner region 176 when the piston 49 is at top dead center TDC. More specifically, one oil injection hole 178A of the piston jet 171A sprays lubricating oil on one pin boss 173 when the piston 49 is at bottom dead center BDC, and the piston when the piston 49 is at top dead center TDC. Lubricating oil is sprayed on the inner region 176. The other oil injection hole 178A of the piston jet 171A sprays lubricating oil on the other pin boss 173 when the piston 49 is at bottom dead center BDC and into the piston inner region 176 when the piston 49 is at top dead center TDC. Spray lubricating oil. That is, the piston jet 171A can spray the lubricating oil on either one of the pair of pin bosses 173 and the piston inner region 176 at one oil injection hole 178.

Further, the injection direction J of the lubricating oil of the piston jet 171 is sandwiched between the inner edge 181t of the pin boss 173 of the piston 49 at the top dead center TDC and the inner edge 181b of the pin boss 173 of the piston 49 at the bottom dead center BDC. It is included in the injection region 182A. In this injection direction J, when the piston 49 is at the top dead center TDC, the lubricating oil is sprayed on the region inside the inner edge 181t of the pin boss 173, that is, the piston inner region 176, and the piston 49 is at the bottom dead center BDC. At this time, the lubricating oil is sprayed on the region outside the inner edge 181b of the pin boss 173, that is, the region outside the piston inner region 176. In such an injection direction J, when the piston 49 reciprocates between the top dead center TDC and the bottom dead center BDC, the lubricating oil is alternately wiped on the pin boss 173 and the piston inner region 176, and both of them are sprayed. Cool and lubricate the area and the area between both areas.

The straight line connecting the inner edge 181t of the pin boss 173 of the piston 49 at the top dead center TDC and the oil injection hole 178A passes through or more than the outer edge 183 of the pin boss 173 of the piston 49 at the bottom dead center BDC. It is preferable to pass through the outside. Further, the injection angle of the lubricating oil of the piston jet 171A may extend to the outside of the injection region 182A. In other words, as shown in FIGS. 9 and 10, the piston jets 171 and 171A according to the present embodiment lubricate the pin boss 173 when the piston 49 is at either the top dead center TDC or the bottom dead center BDC. Oil is sprayed and lubricating oil is sprayed on the piston inner region 176 when the piston 49 is at either the top dead center TDC or the bottom dead center BDC.

Next, the breather chamber 129 of the engine 11 will be described in detail.

FIG. 11 is a partially enlarged view of the right side surface of the right side case half body of the internal combustion engine according to the present embodiment.

FIG. 12 is a perspective view of a part of the clutch chamber of the internal combustion engine according to the present embodiment.

FIG. 13 is a cross-sectional view of the blow-by gas inlet of the internal combustion engine according to the present embodiment on the line XIII-XIII of FIG.

As shown in FIGS. 11 to 13, the crankcase 41 of the engine 11 according to the present embodiment includes a bearing housing 201 and a blow-by gas inlet 202.

The bearing housing 201 and the blow-by gas inflow port 202 are provided in a portion of the wall portion of the right side case half body 52 that is covered by the right side case cover 54, that is, a portion in the clutch chamber 203.

The bearing housing 201 holds the bearing 205. The bearing 205 rotatably supports the counter shaft 65. The bearing housing 201 and the bearing 205 rotatably support the clutch 206 and the primary driven gear 207 via the counter shaft 65.

The primary driven gear 207 is rotatably provided on the counter shaft 65. The crankshaft 47 is provided with a primary drive gear (not shown) integrally rotated. The primary drive gear is always meshed with the primary driven gear 207 of the counter shaft 65. The primary driven gear 207 transmits the rotational force to the counter shaft 65 by connecting the clutch 206, or disconnects the rotational force from the counter shaft 65 by disengaging (disconnecting or shutting off) the clutch 206.

The clutch 206 is provided at the shaft end of the counter shaft 65. The clutch 206 transmits or disengages rotation (rotational driving force) between the crankshaft 47 and the counter shaft 65. The clutch 206 integrates the rotation of the counter shaft 65 and the primary driven gear 207 or separates them to transmit rotation (rotational driving force) between the crankshaft 47 and the counter shaft 65. Or shut off.

The clutch 206 and the primary driven gear 207 are housed in the clutch chamber 203. That is, the clutch 206 and the primary driven gear 207 are arranged outside the breather chamber 129. The clutch 206 and the primary driven gear 207 are rotating bodies having the counter shaft 65 as a rotation axis. That is, the rotation center lines of the clutch 206, the primary driven gear 207, and the counter shaft 65 are substantially aligned.

The blow-by gas inlet 202 is a flow path for blow-by gas that connects the clutch chamber 203 and the breather chamber 129. The blow-by gas inflow port 202 causes blow-by gas to flow from the clutch chamber 203 into the breather chamber 129 (solid line arrow F in FIG. 13).

The blow-by gas inlet 202 is a part around the bearing housing 201 and is located at a position obscured by the clutch 206 and the primary driven gear 207 when viewed from the direction along the rotation center line of the counter shaft 65 (for example, FIG. 11). Have been placed. The blow-by gas inlet 202 has a partial annular shape (arc shape) following the outer peripheral shape of the bearing housing 201. The blow-by gas inlet 202 has a smaller opening dimension L2 in the radial direction than an opening dimension L1 in the circumferential direction of the partial ring.

The second transmission lubricating oil passage 92 that guides the lubricating oil from the reservoir 89 to the shaft end 66a of the drive shaft 66 bypasses the lower edge of the bearing housing 201, while the blow-by gas inlet 202 is above the bearing housing 201. Is located in. In other words, the bearing housing 201 is sandwiched between the blow-by gas inlet 202 on the upper side and the second transmission lubricating oil passage 92 on the lower side.

When the clutch 206 and the primary driven gear 207 rotate, the lubricating oil supplied from the second transmission lubricating oil passage 92 to the shaft end 66a of the counter shaft 65 is the clutch 206 and the primary driven gear in addition to the transmission 63. It is also used for lubrication of 207. The lubricating oil that lubricates the clutch 206 and the primary driven gear 207 is scattered in the clutch chamber 203 by the rotation of the clutch 206 and the primary driven gear 207.

Splashes of lubricating oil scattered from the clutch 206 and the primary driven gear 207 are formed in the clutch 206 and the primary driven gear 207 by weight reduction ports (not shown), dents (not shown), and the clutch 206 and the primary driven gear 207. A non-flat portion such as a spring (not shown) that cushions the impact between the counter shaft 65 and the speed component in the rotation center line direction, and the circumferential direction (rotation direction) of the clutch 206 and the primary driven gear 207. The speed component is given. Therefore, the splash of the lubricating oil scattered from the clutch 206 and the primary driven gear 207 is radially scattered outward from the clutch 206 and the primary driven gear 207, while the rotation center line direction (axial direction) of the counter shaft 65. , And diffuses in the circumferential direction (rotational direction). As a result, a part of the splash of the lubricating oil contained in the blow-by gas goes to the blow-by gas inlet 202.

Therefore, the crankcase 41 of the engine 11 according to the present embodiment is provided integrally with the crankcase 41, protrudes from the bearing housing 201, and is blow-by gas when viewed from the direction along the rotation center line of the clutch 206 and the primary driven gear 207. It is provided with a flange portion 211 that covers at least a part of the inflow port 202.

The flange portion 211 covers a portion of the opening edge of the blow-by gas inlet 202 that is close to the bearing housing 201, that is, the inner diameter side 202a of the partial annular shape. It is preferable that the flange portion 211 extends over the entire width (total length in the circumferential direction of the bearing housing 201) of the inner diameter side 202a of the blow-by gas inlet 202. The flange portion 211 may cover the entire blow-by gas inlet 202. However, in the case of the cast crankcase 41, it is preferable that the flange portion 211 is not larger than the outer diameter side of the blow-by gas inlet 202.

Further, the crankcase 41 is integrally provided with the crankcase 41, and is along the front side 202b in the rotation direction (solid line arrow R in FIG. 11) of the clutch 206 and the primary driven gear 207 in the opening edge of the blow-by gas inlet 202. A bank portion 212 extending in the radial direction of the bearing housing 201 and protruding from the crankcase 41 toward the clutch 206 and the primary driven gear 207 is provided.

The bank portion 212 extends from the bearing housing 201 and reaches the edge of the crankcase 41. In other words, the bank portion 212 includes one end that abuts on the bearing housing 201 and the other end that abuts on the edge of the crankcase 41. The bank portion 212 passes through the center of the bearing housing 201, that is, the rotation center line of the clutch 206 and the primary driven gear 207, and extends along a virtual straight line extending in the radial direction of the bearing housing 201.

The bank portion 212 preferably extends over the entire length of the front side 202b of the blow-by gas inflow port 202. The bank portion 212 may be separated from the bearing housing 201 or may be separated from the edge of the crankcase 41. The bank portion 212 may be inclined or curved with respect to a virtual straight line passing through the center of the bearing housing 201 and extending in the radial direction of the bearing housing 201.

The flange portion 211 and the bank portion 212 are integrally molded with the crankcase 41. In the cast crankcase 41, the flange portion 211 and the bank portion 212 are integrally molded with the crankcase 41 by a mold. In other words, the blow-by gas inflow port 202, the flange portion 211, and the bank portion 212 are formed on the crankcase 41 by the mold. The flange portion 211 and the bank portion 212 are integrally molded with the crankcase 41 without using fastening parts such as screws as in the breather plate in a conventional engine.

The flange portion 211 and the bank portion 212 prevent the splashes of lubricating oil scattered with the rotation of the clutch 206 and the primary driven gear 207 from directly jumping (flowing in or flowing in) into the blow-by gas inlet 202 together with the blow-by gas. I'm out. The splashes of the lubricating oil are scattered outward in the radial direction of the clutch 206 and the primary driven gear 207, and are diffused in the axial direction and the circumferential direction of the counter shaft 65. The brim 211 and the bank 212 are familiar expressions, but they function like the eaves of a house or the brim of a hat to block the splash of lubricating oil, and the splash of lubricating oil jumps into the blow-by gas inlet 202. Prevent that. The flange portion 211 blocks the splash of the lubricating oil that diffuses exclusively in the axial direction, and the bank portion 212 blocks the splash of the lubricating oil that diffuses exclusively in the circumferential direction.

FIG. 14 is an enlarged view of a part of FIG. 6 to show a breather chamber of an internal combustion engine according to the present embodiment.

FIG. 15 is a diagram showing a breather chamber of an internal combustion engine according to the present embodiment by enlarging a part of FIG. 7.

In addition to FIG. 13, as shown in FIGS. 14 and 15, the breather chamber 129 of the engine 11 according to the present embodiment has a so-called labyrinth structure. That is, the breather room 129 has a plurality of small rooms 215 partitioned across the right side case half body 52 and the left side case half body 51.

The plurality of small rooms 215 include a first small room 216a connected to the blow-by gas inlet 202, a second small room 216b connected to the first small room 216a, and a third small room 216c connected to the second small room 216b. Includes.

Each small room 215 is partitioned across the right case half body 52 and the left case half body 51. That is, each small room 215 includes a portion partitioned by the right side case half body 52 with the connecting surface 41a of the crankcase 41 as a boundary, and a portion partitioned by the left side case half body 51. The partial small room 215a on the right side case half 52 side is open toward the left case half 51, and the partial small room 215b on the left side case half 51 side is open toward the right case half 52.

Here, a virtual boundary between the partial small room 215a and the partial small room 215b, that is, extending in the direction of the adjacent small room 215 intersecting the joint surface 41a and dividing each of the partial small room 215a and the partial small room 215b into two. Determine the target division surface DP. With this division surface DP as a reference (boundary), one side of the partial small room 215a to be divided is set as one corner 217aa of the partial small room 215a, and the other side is used as the other corner 217ab of the partial small room 215a. Further, with the division surface DP as a reference (boundary), one side of the partial small room 215b to be divided is set as one corner 217ba of the partial small room 215b, and the other side is set as the other corner 217bb of the partial small room 215b. .. In other words, each subchamber 215 has a pair of subchambers 215a, 215b, and has four corners 217aa, corners 217ab, corners 217ba, and corners 217bb.

The shape of the small room 215 is not limited to a rectangle, and may be a polygon including a triangle or a trapezoid, a circle, or an ellipse. The small chambers 215 having these shapes are also divided into four regions based on the virtual division surface DP intersecting the joint surface 41a, and these divisions are called corners.

Further, in order to make it easy to understand the arrangement of each corner portion 217aa, 217ab, 217ba, and 217bb in the present embodiment, the corner portion 217aa is referred to as a lower right corner portion 217aa, the corner portion 217ab is referred to as an upper right corner portion 217ab, and the corner portion. The 217ba is referred to as a lower left corner portion 217ba, and the corner portion 217bb is referred to as an upper left corner portion 217bb. However, the directionality of each small room 215 is not limited to this, and each corner portion 217aa, 217ab, 217ba, and 217bb is divided in the front-rear direction, or is divided in an inclined manner with respect to a horizontal plane or a vertical plane. May be.

The blow-by gas inflow port 202 is arranged in the lower right corner portion 217aa of the first small room 216a (one corner portion aa on the right side case half body 52 side). The first small room 216a and the second small room 216b are connected by an upper left corner portion 217bb (the other corner portion 217bb on the left side case half body 51 side). The second small room 216b and the third small room 216c are connected by a lower right corner 217aa (one corner 217aa on the right side of the case half body 52 side. That is, each small room 215 is on the upstream side at a certain corner. It is connected to the small room 215, and is connected to the small room 215 on the downstream side through the central part of the small room 215 or at the diagonal corners straddling the central part of the small room 215.

In other words, the breather room 129 has a first blow-by gas distribution port 218a connecting the upper left corner 217bb of the first small room 216a and the second small room 216b, and a lower right corner of the second small room 216b and the third small room 216c. It has a second blow-by gas flow port 218b for connecting 217aa. Although it is a familiar expression, the breather room 129 distributes blow-by gas in a zigzag manner while passing through the central part of each small room 215. Such a zigzag distribution channel can obtain a longer channel length in a limited volume.

The plurality of small rooms 215 are partitioned by a curved partition wall 221. There are a plurality of partition walls 221 facing each other in each small room 215. The plurality of small rooms 215 are arranged in layers so as to move away from the center of the fan shape from the first small room 216a on the upstream side near the blow-by gas inlet 202 to the third small room 216c on the downstream side. The plurality of small rooms 215 are arranged so as to overlap the partial circles in the entire breather room 129.

The partially annular chambers 215 arranged in this way generate centrifugal force in the flow of blow-by gas. This centrifugal force centrifuges the splashed lubricating oil contained in the blow-by gas from the blow-by gas. The breather chamber 129 synergizes the centrifuge effect with the zigzag flow path of blow-by gas.

Further, in the flow of blow-by gas, the small room 215 on the downstream side of the second small room 216b, that is, the third small room 216c is provided in the right case half body 52 and allows the flow of blow-by gas to flow in the third small room 216c. A partition plate 223 for moving back and forth from the right case half body 52 side (partial small room 215a side) to the right case half body 52 side (partial small room 215a side) via the left case half body 51 side (partial small room 215b side). Have.

The partition plate 223 reaches the joint surface 41a of the third small room 216c and divides the partial small room 215a of the partial small room 215a into two. That is, the partition plate 223 curves the flow of blow-by gas in the third small room 216c.

The plurality of small chambers 215 are partitioned into a partition wall 221 having a large radius of curvature as the distance from the blow-by gas inlet 202 (toward the downstream side) increases, forming a partial annular shape having a large radius of curvature. Therefore, the small room 215 on the downstream side can easily secure a larger volume than the small room 215 on the upstream side. Therefore, the small room 215 on the downstream side of the second small room 216b, that is, the third small room 216c is further subdivided into the small room 215 by the partition plate 223, so that the flow of blow-by gas is curved many times. The splashed lubricating oil contained in the blow-by gas is separated from the blow-by gas.

There may be a plurality of partition plates 223 in one small room 215. That is, the partition plate 223 is provided on the right side case half body 52 or the left side case half body 51 to allow the flow of blow-by gas to flow to one of the case half body sides of the small room 215 (either the right side case half body 52 or the left side case half body 51). It is moved back and forth from one side) to the other case half side (the other side of the right side case half 52 and the left case half 51) and back to the other case half side.

At the bottom of each small chamber 215, an oil outflow hole 225 is provided to allow the lubricating oil condensed in the small chamber 215 to flow out. The oil outflow hole 225 straddles the coupling surface 41a of the crankcase 41. The oil outflow hole 225 is an opening in which notch-shaped recesses provided in each of the left and right case halves 51 and 52 are combined.

The breather chamber 129 according to the present embodiment causes blow-by gas to flow from the clutch chamber 203 into the lower right corner portion 217aa of the first small chamber 216a through the blow-by gas inflow port 202 (solid line arrow f1 in FIG. 14). Further, the breather room 129 allows the blow-by gas that has flowed into the lower right corner portion 217aa of the first small room 216a to pass through the central portion (near the joint surface 41a) of the first small room 216a and the upper left corner portion 217bb of the first small room 216a. (Solid arrow f2 in FIG. 15). The breather room 129 causes the blow-by gas that has reached the upper left corner 217bb of the first small room 216a to flow into the upper left corner 217bb of the second small room 216b through the first blow-by gas distribution port 218a (solid line arrow in FIG. 15). f3). The breather room 129 guides the blow-by gas that has flowed into the upper left corner 217bb of the second small room 216b to the lower right corner 217aa of the second small room 216b via the central part (near the joint surface 41a) of the second small room 216b. (Solid arrow f4 in FIG. 15). The breather room 129 causes the blow-by gas that has reached the lower right corner 217aa of the second small room 216b to flow into the lower right corner 217aa of the third small room 216c through the second blow-by gas distribution port 218b (solid line arrow in FIG. 14). f5). In the breather room 129, the blow-by gas that has flowed into the lower right corner 217aa of the third small room 216c is circumvented from the partition plate 223 from the right side case half body 52 side (partial small room 215a side) to the left side case half body 51 side. It is moved back and forth to the right side case half body 52 side (partial small room 215a side) via (partial small room 215b side) (solid line arrow f6 in FIG. 15). Then, the breather chamber 129 causes the blow-by gas that has reached the upper right corner 217ab of the third small chamber 216c to flow out from the blow-by gas outflow pipe 226 protruding from the outer surface of the crankcase 41 (solid line arrow f7 in FIG. 14).

The breather room 129 may be arranged so that the flow path of the blow-by gas between the blow-by gas inlet 202 and each small room 215 is inverted up, down, left and right of the engine 11. For example, the blow-by gas inflow port 202 may be provided in the left case half body 51, and the blow-by gas flow port (first blow-by gas flow port 218a, second blow-by gas flow port 218b) connecting each small room 215 may also be provided. , Left and right may be reversed.

Further, the blow-by gas inflow port 202 may be connected to the upper right corner portion 217ab of the first small room 216a. In this case, it is preferable that the first blow-by gas flow port 218a connects the first small room 216a and the second small room 216b at the lower left corner portion 217ba. The same applies to the second blow-by gas distribution port 218b.

Here, either one of the right side case half body 52 and the left side case half body 51 is referred to as a first case half body, and the other is referred to as a second case half body. That is, the breather room 129 has a plurality of small rooms 215 partitioned across the first case half body and the second case half body.

The engine 11 is an internal combustion engine provided integrally with each of the first wall portion 51b of the right case half body 52 for partitioning the breather chamber 129 and the second wall portion 51a of the left case half body 51 for partitioning the breather chamber 129. It is equipped with a boss 228 for engine suspension. The internal combustion engine suspension boss 228 has a boss half body 228a integrally provided on the right side case half body 52 and a boss half body 228b integrally provided on the left side case half body 51. The boss half body 228a and the boss half body 228b are connected and integrated by the connecting surface 41a of the crankcase 41.

The breather room 129 has a labyrinth structure by a partition wall 221 that partitions the small room 215. Therefore, the breather chamber 129 has higher rigidity than other parts of the crankcase 41. The internal combustion engine suspension boss 228 is integrated with the breather chamber 129 having such high rigidity.

Further, in the third small room 216c of the breather room 129, a partition plate 223 that crosses the room is provided. The partition plate 223 extends in the radial direction of the internal combustion engine suspension boss 228. Therefore, the third small chamber 216c has higher rigidity than other parts of the crankcase 41. The internal combustion engine suspension boss 228 is integrated with the third small chamber 216c of the breather chamber 129 having such high rigidity.

The engine 11 according to the present embodiment has a pump discharge side oil passage 101 in which lubricating oil is discharged from the oil pump 96, a guide oil passage 158 for guiding the lubricating oil collected in the crank chamber 67 to the scavenging pump 95, and a pump. It is provided with a partition wall 159 that separates the discharge side oil passage 101 and the guide oil passage 158 by a pair of front and back wall surfaces 159a and 159b. Therefore, the engine 11 has a wall for partitioning the pump discharge side oil passage 101 through which the lubricating oil discharged from the oil pump 96 passes, and a wall for partitioning the guide oil passage 158 through which the lubricating oil sucked into the scavenging pump 95 passes. , Can be partitioned by one partition wall 159. That is, the engine 11 does not need to be separately provided with a wall separating the pump discharge side oil passage 101 and the guide oil passage 158, and the weight can be reduced.

Further, the engine 11 according to the present embodiment hangs on the projection region of the oil pump 96 toward the crank chamber 67 side and curves toward the transmission chamber 68 side as it approaches the scavenging pump 95, and the suction port 135 of the scavenging pump 95. It is equipped with a partition wall 159 that reaches. Therefore, the engine 11 has a shape suitable for feeding the lubricating oil discharged from the oil pump 96 to the partition wall 159 and for guiding the lubricating oil sucked into the scavenging pump 95.

Further, the engine 11 according to the present embodiment includes a partition wall 159 having a substantially uniform plate thickness. Therefore, the engine 11 has a wall for partitioning the pump discharge side oil passage 101 through which the lubricating oil discharged from the oil pump 96 passes, and a wall for partitioning the guide oil passage 158 through which the lubricating oil sucked into the scavenging pump 95 passes. , Can be made lighter.

Furthermore, the engine 11 according to the present embodiment includes a scavenging pump 95 that discharges lubricating oil in the radial direction. Therefore, the engine 11 does not discharge the lubricating oil from the scavenging pump 95 so as to cross between the oil pump 96 and the crank chamber 67, and causes the oil pump 96 to be adjacent to the crank chamber 67 from the oil pump 96. A wall partitioning the pump discharge side oil passage 101 through which the discharged lubricating oil passes and a wall partitioning the guide oil passage 158 through which the lubricating oil sucked into the scavenging pump 95 passes are separated by one partition wall 159. can.

Further, the engine 11 according to the present embodiment partitions the inner wall of the transmission chamber 68, that is, the discharge oil passage 125 for discharging the lubricating oil from the scavenging pump 95 to the transmission chamber 68 facing the first common partition wall 122. A discharge oil passage partition wall 126 is provided. Therefore, the lubricating oil is not discharged from the scavenging pump 95 so as to cross between the oil pump 96 and the crank chamber 67, and the oil pump 96 is adjacent to the crank chamber 67 and the lubricating oil is discharged from the oil pump 96. A wall partitioning the pump discharge side oil passage 101 through which the oil passes and a wall partitioning the guide oil passage 158 through which the lubricating oil sucked into the scavenging pump 95 passes can be partitioned by one partition wall 159.

Further, the engine 11 according to the present embodiment has a pair of pump accommodating portions 131a and 151a which are opened in the opposite direction to one member, for example, the right side case half body 52 and accommodating the oil pump 96 and the scavenging pump 95, respectively. Have. Therefore, the engine 11 accommodates the oil pump 96 and the scavenging pump 95 in one member, and has a pump discharge side oil passage 101 through which the lubricating oil discharged from the oil pump 96 is passed by the partition wall 159 of this member, and scavenging. It is possible to partition the guide oil passage 158 through which the lubricating oil sucked into the pump 95 passes.

Therefore, according to the engine 11 according to the present embodiment, the pump discharge side oil passage 101 through which the lubricating oil discharged from the oil pump 96 passes, and the guide oil passage 158 through which the lubricating oil sucked into the scavenging pump 95 passes are provided. The wall that separates them, that is, the partition wall 159, can be made lighter, and the overall weight can be made lighter.

1 ... Motorcycle, 2 ... Body frame, 5 ... Front wheel, 6 ... Steering mechanism, 7 ... Rear wheel, 8 ... Swing arm, 11 ... Internal engine, 11 ... Engine, 12 ... Fuel tank, 13 ... Seat, 15 ... Body Cover, 21 ... head pipe, 22 ... main tube, 23 ... down tube, 25 ... seat rail, 26 ... seat pillar, 27 ... front fork, 28 ... front fender, 29 ... handle, 31 ... rear cushion unit, 32 ... drive Chain, 33 ... oil cooler, 35 ... front cover, 36 ... side cover, 37 ... rear cover, 41 ... crank case, 41a ... joint surface, 42 ... cylinder, 43 ... cylinder head, 43a ... outlet flange, 43b ... inlet flange, 44 ... Head cover, 45 ... Transmission case, 47 ... Crank shaft, 47a ... Shaft end, 47b ... Counter weight, 48 ... Cylinder bore, 49 ... Piston, 51 ... Left case half body, 51a ... Second wall, 52 ... Right case half body, 51b ... First wall, 53 ... Left case cover, 54 ... Right case cover, 55, 56 ... Oil hose, 57 ... Fan, 59 ... Oil passage, 59a ... Crank case oil passage, 59b ... Cylinder oil passage, 59c ... Cylinder head oil passage, 61 ... Oil pan, 61a ... Bottom, 62 ... Valve mechanism, 63 ... Transmission, 65 ... Counter shaft, 65a ... Shaft end, 66 ... Drive shaft, 66a ... Shaft end, 67 ... Crank chamber, 67a ... Part, 68 ... Transmission chamber, 69 ... Exhaust port, 70 ... Combustion chamber, 75 ... Crank shaft lubricating oil passage, 76 ... Piston cooling oil passage, 81 ... First oil passage, 82 ... 2nd oil passage, 83 ... 3rd oil passage, 84 ... 4th oil passage, 85 ... 5th oil passage, 86 ... 6th oil passage, 87 ... 7th oil passage, 88 ... 8th oil passage, 89 ... Reservoir, 89a ... One end, 89b ... The other end, 91 ... First transmission lubricating oil passage, 92 ... Second transmission lubricating oil passage, 95 ... Scavenging pump, 95a ... Outer rotor, 95b ... Inner rotor, 95c ... The part closest to the bottom of the oil pan, 95d ... Rotating shaft core, 96 ... Oil pump, 96a ... Outer rotor, 96b ... Inner rotor, 96c ... Rotating shaft core, 98 ... First oil filter, 99 ... second oil filter, 101 ... pump discharge side oil passage, 105 ... counter gear, 106 ... drive gear, 108 ... second reservoir, 109 ... Magneto, 111 ... Ninth oil passage, 121 ... Oil storage chamber, 122 ... First common partition, 123 ... Second common partition, 125 ... Discharge oil passage, 126 ... Discharge oil passage partition wall, 128 ... Plate body, 129 ... Breather chamber, 131 ... Scavenging pump housing, 132 ... Oil pan bottom wall, 131a ... Pump housing, 131b ... Pump storage lid, 135 ... Suction port, 135a ... Suction port 136 ... Discharge port, 141 ... Suction port, 142 ... Filter upstream oil passage, 143 ... Filter housing, 144 ... Filter downstream oil passage 146 ... Plate wall, 147 ... Oil block, 151 ... Oil pump housing, 152 ... Auxiliary driven gear , 151a ... Pump housing, 151b ... Pump storage lid, 155 ... Suction port, 155a ... Suction port, 156 ... Discharge port, 158 ... Guide oil passage, 159 ... Bulk partition, 159a ... Crank chamber side wall surface, 159b ... Wall surface , 171, 171A ... Piston jet, 173 ... Pin boss, 173a ... Inner side surface, 174 ... Skirt, 174a ... Inner side surface, 175 ... Side wall, 175a ... Inner side surface, 176 ... Piston inner surface area, 178, 178A ... Oil injection hole, 181t ... inner edge, 181b ... inner edge, 182, 182A ... injection region, 183 ... outer edge, 201 ... bearing housing, 202 ... blow-by gas inlet, 202a ... inner diameter side, 202b ... front side, 203 ... clutch chamber, 205 ... Bearing, 206 ... Clutch, 207 ... Primary driven gear, 211 ... Collar, 212 ... Bank, 215 ... Small room, 215a ... Right case half-body side partial small room, 215b ... Left case half-body side partial small room, 216a ... first small room, 216b ... second small room, 216c ... third small room, 217a ... one corner, 217b ... the other corner, 217aa ... lower right corner, 217ab ... upper right corner, 217ba ... lower left corner 217bb ... upper left corner 218a ... first blow-by gas flow port 218b ... second blow-by gas flow port 221 ... partition wall 223 ... partition plate 225 ... oil outflow hole 226 ... blow-by gas outflow pipe 228 ... Internal combustion engine suspension boss 228a ... Right case half boss half 228b ... Left case half boss half.

Claims (5)

The crankcase that separates the crankcase and
An oil storage unit provided at the bottom of the crankcase to store lubricating oil,
The cylinder combined with the crankcase and
A transmission case that is integrated with the crankcase and divides the transmission chamber,
A feed pump for pumping the lubricating oil to be lubricated portion,
An oil supply passage that includes an outward path for feeding the lubricating oil pumped from the oil storage unit to the oil passage of the cylinder and discharges the lubricating oil from the feed pump.
A recovery pump that discharges the lubricating oil accumulated in the crank chamber to the discharge oil passage leading to the transmission chamber, and
A guide oil passage that guides the lubricating oil accumulated in the crank chamber to the recovery pump, and
A partition wall that separates the oil supply passage and the guide oil passage by a pair of front and back wall surfaces.
A crankshaft housed in the crankcase with the rotation center line directed in the width direction of the crankcase .
The crankcase and the transmission case are arranged in the front-rear direction.
The crankcase and the transmission case can be divided into a pair of halves at a coupling surface orthogonal to the rotation center line of the crankshaft.
The feed pump, the recovery pump, the oil supply passage, the guide oil passage, and the partition wall are provided in any one of the semifields.
Is one of the halves, it said opened in the opposite direction to the rotational center line direction of the crankshaft, the feed pump and an internal combustion engine that has a pair of pump accommodating portion for accommodating each of the recovery pump. The crank chamber has a suction port for sucking the lubricating oil from the guide oil passage to the recovery pump.
The internal combustion engine according to claim 1, wherein the partition wall hangs on a projection region of the feed pump toward the crank chamber side, bends toward the transmission chamber side as it approaches the recovery pump, and reaches the suction port. The internal combustion engine according to claim 1 or 2, wherein the partition wall has a substantially uniform plate thickness. The internal combustion engine according to any one of claims 1 to 3, wherein the recovery pump discharges the lubricating oil in the radial direction. From claim 1, wherein the discharge oil passage wall provided in the transmission chamber is provided to partition the discharge oil passage for discharging the lubricating oil from the recovery pump to the transmission chamber facing the inner wall surface of the transmission chamber. 4. The internal combustion engine according to any one of 4.

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