JP2005030326A - Engine for motorcycle, and motorcycle with the engine mounted thereon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an engine for a motorcycle capable of preventing a clutch from being immersed in oil after the engine is stopped, and easily releasing the clutch when the engine is started, and to provide a motorcycle with the engine mounted thereon. <P>SOLUTION: A crank chamber 20 is formed inside a crank case 8 comprising a left crank case 10 and a right crank case 11 joined with each other, and a clutch chamber 24 is formed by successively joining the left crank case 10, an inner clutch cover 12 and an outer clutch cover 13 with each other. Oil passage between the crank chamber 20 and the clutch chamber 24 is restricted by a partition wall 38. Oil stored in both chambers is sucked by pumps 64 and 65 which are separately provided for each chamber. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motorcycle engine and a motorcycle equipped with the engine.

  An engine mounted on a motorcycle mainly includes an upper cylinder, a lower crankcase, and an oil pan at the bottom of the crankcase. A crank chamber for storing the crankshaft and a clutch chamber for storing the clutch are provided in the crankcase. A handle of the motorcycle is provided with a clutch lever, and an operator can disengage the clutch or connect the clutch by operating the clutch lever.

  In such an engine, oil (engine oil) used for lubrication and cooling is circulated through various places in the engine. One form of circulating oil in the engine is a dry sump type (see Patent Document 1).

  Dry sump engines are equipped with an oil pump (scavenging pump) for collecting the oil in the oil pan to the oil tank and an oil pump (feed pump) for pumping the oil in the oil tank to various parts of the engine. ing. Both the scavenging pump and the feed pump are driven by engine operation (crankshaft rotation).

  Oil that has been used for lubrication and cooling at various locations in the engine falls to the oil pan, or descends along the inner wall surfaces of the crank chamber and the clutch chamber, and is collected in the oil pan. The oil collected in the oil pan is sucked up by a scavenging pump through one suction port (scavenge mouse) provided in the oil pan, and collected in an oil tank provided separately from the oil pan. The oil in the oil tank is pumped to various places in the engine by a feed pump, and again used for lubrication and cooling.

Since such a dry sump engine does not need to store a large amount of oil in the oil pan, the oil pan can be made shallow and the overall height of the engine can be lowered. Further, since the amount of oil accumulated in the oil pan is small, it is possible to reduce the stirring resistance generated when the rotating crankshaft contacts the oil when the engine is operating.
Japanese Patent Laid-Open No. 2003-14094

  By the way, many motorcycles employ a side stand as a stand, and such a motorcycle generally includes a side stand on the left side of the vehicle body. When supported by the side stand, the vehicle body is slightly inclined to the left side, and the oil pan is also inclined so that the left side is downward.

  On the other hand, since the crank chamber and the clutch chamber usually share an oil pan, the oil transmitted through the inner wall surfaces of the crank chamber and the clutch chamber is concentrated in the oil pan and stored in the oil pan as described above. The oil thus obtained can freely move between the crank chamber and the clutch chamber through the oil pan.

  Therefore, in the case of an engine in which the clutch chamber is disposed on the side where the side stand is disposed with respect to the vehicle body, that is, in the above example, on the left side of the crank chamber, if the engine is stopped by supporting the vehicle body by the side stand, The oil in the pan flows to the left side where the vehicle body tilts and is collected at the inner bottom of the clutch chamber. Further, the oil adhering to the inner wall surface of the crank chamber is also collected on the inner bottom portion of the clutch chamber along the inner wall surface.

  In particular, American-style motorcycles tend to emphasize the beauty of the appearance when viewed from the right side, so the clutch chamber is often arranged on the left side of the engine. Therefore, in such an American type motorcycle, when the vehicle body is supported by the side stand, oil tends to collect at the inner bottom portion of the clutch chamber.

  For this reason, in a state where the vehicle body is tilted while being supported by the side stand, the oil level in the clutch chamber becomes high, and the clutch may be immersed in the oil. Since the viscosity of the oil increases as the temperature decreases, if the engine cools down with the clutch immersed in the oil, the clutch will be cut off due to the viscous resistance of the oil. Accordingly, the clutch may be difficult to disengage during the period from the start of the engine especially in winter to the warming of the engine.

  Therefore, the present invention provides an engine for a motorcycle capable of maintaining a good clutch disengagement without causing the clutch to be immersed in oil after the engine is stopped, and a motorcycle equipped with the engine. Objective.

  The present invention has been made in view of the above circumstances, and a motorcycle engine according to the present invention includes a crank chamber that houses a crankshaft, and a clutch that is disposed on the side of the crank chamber. A clutch chamber, and a scavenging pump for sucking in the oil accumulated in the crank chamber and the inner bottom of the clutch chamber, and a partition is provided between the crank chamber and the clutch chamber. The flow of oil in is restricted.

  In this case, since the crank chamber and the clutch chamber are partitioned by the partition wall, the oil accumulated in the inner bottom portion of the crank chamber does not flow into the clutch chamber. Further, it is possible to prevent oil flowing down along the inner wall surface of the crank chamber from entering the clutch chamber after the engine is stopped. Therefore, it is difficult for oil to accumulate in the clutch chamber after the engine is stopped, and the clutch can be prevented from being oiled.

  The clutch chamber may be disposed on the same side as the side stand with respect to the vehicle body with respect to the crank chamber. In this case, even if the vehicle body is tilted by supporting the vehicle body with the side stand and the clutch chamber is positioned below the crank chamber, the oil accumulated in the inner bottom of the crank chamber is transferred to the clutch chamber by the partition wall. Intrusion is prevented. Therefore, it is possible to prevent the clutch from being immersed in oil after the engine is stopped.

  Further, as the scavenging pump, a crank chamber pump for sucking oil in the crank chamber and a clutch chamber pump for sucking oil in the clutch chamber may be provided separately.

  For example, when an oil passage is extended from the inner bottom portion of the crank chamber and the inner bottom portion of the clutch chamber, and the respective oil passages are joined in the middle and connected to one scavenging pump, either the crank chamber or the clutch chamber In some cases, air is sucked from one side, and oil cannot be sucked from the other side.

  Therefore, as described above, the two pumps, the crank chamber pump and the clutch chamber pump, are provided as scavenging pumps, so that the oil accumulated in both the crank chamber and the clutch chamber can be sucked up efficiently and independently. Can be recovered. Therefore, the oil level in the clutch chamber can be reliably reduced.

  An oil reservoir may be formed at the inner bottom of the clutch chamber. In this case, the oil collected in the clutch chamber can be efficiently collected in the oil reservoir. Therefore, more oil can be collected and the oil level in the clutch chamber can be further reduced, and as a result, the clutch can be prevented from being oiled.

  Further, when the above-described engine is mounted on a motorcycle, it is possible to realize a motorcycle that can smoothly perform clutch operation during shifting. Further, when applied to an American type motorcycle, it is possible to have a configuration that maintains the beauty of the appearance while producing the effects described above.

  According to the present invention, it is possible to provide an engine for a motorcycle that can smoothly perform clutch operation at the time of shifting without stopping the engine after the engine is stopped, and a motorcycle equipped with the engine. .

  Hereinafter, a motorcycle engine according to an embodiment of the present invention and a motorcycle equipped with the engine will be specifically described with reference to the drawings. FIG. 1 is a left side view of the motorcycle. A motorcycle 1 shown in FIG. 1 is an American type, and includes a frame 4 that forms a skeleton of a vehicle body between a front wheel 2 and a rear wheel 3, and an engine E is mounted in the frame 4. The engine E is fixed to the frame 4 via a plurality of brackets. A side stand 5 is provided on the left side of the frame 4. In the following description of the present embodiment, description will be made based on directions (front and rear, left and right, and up and down) related to the motorcycle 1 shown in FIG.

  2 is a left side view of the engine E with a part cut away, and FIG. 3 is a right side view of the engine E with a part cut out. The engine E is a V-type two-cylinder four-cycle engine, and cylinders 6 and 7 are arranged in a V shape so as to incline forward and backward, and a crank provided below the cylinders 6 and 7. A case 8 and an oil pan 9 provided below the crankcase 8 are provided.

  FIG. 4 is an exploded perspective view showing main housing parts of the engine E excluding the cylinders 6 and 7. As shown in FIG. 4, the engine E includes a left crankcase 10 and a right crankcase 11 that are paired on the left and right. When the left crankcase 10 and the right crankcase 11 are closed from the left and right to form a crankcase 8, a crank chamber 20, a transmission chamber 21, an output shaft chamber 22, and a separator chamber 23 are contained in the crankcase 8. It is formed.

  As will be described later, a crankshaft is provided in the crank chamber 20, a transmission (transmission) is provided in the transmission chamber 21, and an output shaft is provided in the output shaft chamber 22. Furthermore, the internal space of the transmission chamber 21 is used as an oil tank.

  A recess that is recessed toward the right side (center side) is formed on the left side (outer side) of the left crankcase 10, and the recess forms a part of the clutch chamber 24. An inner clutch cover 12 is attached to the left crankcase 10 from the left side so as to join the edge of the recess and cover the recess, and an outer clutch cover 13 is attached to the left side of the inner clutch cover 12.

  An inner clutch cover 12 is joined to the left crankcase 10, and an outer clutch cover 13 is joined to the inner clutch cover 12, whereby a clutch chamber 24 is formed inside the cover. As will be described later, a generator for power generation and a clutch are provided in the clutch chamber 24.

  A cam cover 14 is attached to the front side of the right side (outer side) of the right crankcase 11. A space between the right crankcase 11 and the cam cover 14 forms a cam chamber 25, and a cam, a cam chain, and the like, which will be described later, are accommodated in the cam chamber 25. Further, an inner mission cover 15 is attached to a position near the right side of the right crankcase 11, and an outer mission cover 17 is attached to the right side of the inner mission cover 15. An internal space formed by the inner mission cover 15 and the outer mission cover 17 forms an oil storage chamber 26.

  An oil pan 9 is attached to the lower part of the left crankcase 10 and the right crankcase 11. As a result, the oil pan 9 is located below the crank chamber 20 and the transmission chamber 21.

  In addition, although not shown in figure, the sealing member is interposed between each member mentioned above, and gas and a liquid are not intended to leak from the connection location between each member unintentionally.

  FIG. 5 is a VV cross-sectional view of the engine E shown in FIG. As shown in FIG. 5, in the engine E, the crank chamber 20 is located below the cylinders 6 and 7, and a transmission chamber 21 is disposed behind the crank chamber 20. Further, an output shaft chamber 22 is disposed behind the transmission chamber 21, and at the same time, the transmission chamber 21 extends to the right rear of the output shaft chamber 22. A separator chamber 23 is disposed behind the output shaft chamber 22. Further, a clutch chamber 24 is disposed on the left side of the engine E and on the left side of the crank chamber 20 and the transmission chamber 21, and an oil storage chamber 26 is disposed on the right side of the engine E and on the right side of the transmission chamber 21. Has been placed.

  The crank chamber 20, the transmission chamber 21, the output shaft chamber 22, the separator chamber 23, and the clutch chamber 24 are integrally formed by a crank case 8 formed by closing the left crank case 10 and the right crank case 11. .

  Since the engine E formed integrally in this way can reduce the number of parts compared to the case where the transmission chamber 21, the output shaft chamber 22, and the separator chamber 23 are configured separately from the crank chamber 20, Engine weight and assembly man-hours can also be reduced. Further, the engine E can be made compact.

  Further, the engine E is fixed to the frame 4 (see FIG. 1) by a plurality of brackets (not shown), but each chamber is integrally formed with the crankcase 8 so that a casing prepared for each chamber is provided. It is not necessary to fix the parts individually to the frame 4. As a result, the assembly accuracy of the engine E to the frame 4 is also improved, and positional deviation is less likely to occur.

  A crankshaft 30 is housed in the crank chamber 20 so as to be rotatably supported so that its axis is directed in the left-right direction. A piston 33 is connected to the crankpin 31 of the crankshaft 30 via a connecting rod 32. The piston 33 reciprocates substantially vertically along the inner wall surfaces of the cylinders 6 and 7 in conjunction with the rotation of the crankshaft 30.

  The right end portion of the crankshaft 30 penetrates the right crankcase 11 and protrudes into the cam chamber 25, and is connected to the cam sprockets 34 and 35 via a chain (see FIG. 3). Further, the right end portion of the crankshaft 30 is also connected to balancer shafts 36 and 37 disposed before and after the crankshaft 30 via a chain (see FIG. 3).

  The balancer shafts 36 and 37 are arranged in parallel to the crankshaft 30, and weights are provided on the shaft (not shown). The balancer shafts 36 and 37 rotate with the rotation of the crankshaft 30 to suppress vibration of the engine E itself caused by the operation of the engine E. As will be described later, the balancer shaft 37 disposed on the rear side drives an oil pump for pumping or sucking up oil circulating in the engine E.

  As shown in FIG. 5, a partition wall 38 formed in the left crankcase 10 is provided between the crank chamber 20 and the clutch chamber 24 to partition both chambers. The left end portion of the crankshaft 30 passes through the partition wall 38 and protrudes into the clutch chamber 24, and a generator 39 for power generation is provided at the left end portion.

  A main shaft 40 and a counter shaft 41 are rotatably supported in the transmission chamber 21 such that the shaft core is parallel to the crankshaft 30. The main shaft 40 and the countershaft 41 are hollow tubular, and the inside forms an oil passage 42. A left end portion of the main shaft 40 passes through a partition wall 43 that partitions the transmission chamber 21 and the clutch chamber 24 and protrudes into the clutch chamber 24, and a clutch 44 is provided at the left end portion.

  The crankshaft 30 and the main shaft 40 are connected to each other in the clutch chamber 24 via a sprocket and a chain. When the clutch 44 is engaged, the rotational force of the crankshaft 30 is transmitted to the main shaft 40 via the sprocket and chain, and when the clutch 44 is disengaged, the rotational force of the crankshaft 30 is the main shaft. 40 is not transmitted.

  The right end portions of the main shaft 40 and the counter shaft 41 pass through the inner mission cover 15 and open in the oil storage chamber 26. Therefore, the oil storage chamber 26 communicates with the oil passages 42 in the main shaft 40 and the counter shaft 41.

  The main shaft 40 and the counter shaft 41 are provided with a transmission 45 composed of a plurality of gears having different diameters. When an operator operates a change lever (not shown), a predetermined gear of the main shaft 40 and the counter shaft 41 A predetermined gear is in mesh. In addition, a plurality of oil injection holes 46 that pass through the peripheral portions of the main shaft 40 and the counter shaft 41 and communicate with the internal oil passage 42 are provided at the base positions of the plurality of gears forming the transmission 45.

  An output shaft 47 is rotatably supported in the output shaft chamber 22 such that the axis is parallel to the counter shaft 41. The right end portion of the output shaft 47 protrudes from the output shaft chamber 22 to the transmission chamber 21. Gears that mesh with each other are provided at the right end portion of the output shaft 47 and the right end portion of the counter shaft 41, and the rotational force of the counter shaft 41 is transmitted to the output shaft 47 via the gears.

  The left end portion of the output shaft 47 protrudes from the output shaft chamber 22 to the left side outside the crankcase 8, and a pulley 48 is provided at the left end portion. A belt is stretched between the pulley 48 and the shaft of the rear wheel 3 (see FIG. 1) of the motorcycle 1 so that the rotational force of the output shaft 47 is transmitted to the rear wheel 3. .

  FIG. 6 is a perspective view of the oil pan 9. As shown in FIG. 6, the oil pan 9 has a rectangular shape that is long in the front-rear direction in plan view. A partition wall 50 is erected at a position rearward of the center in the front-rear direction. The partition wall 50 partitions the front crank chamber oil pan 51 and the rear mission chamber oil pan 52.

  The crank chamber oil pan 51 is inclined so that the inner bottom surface is directed downward from the left and right ends to the center position, and the bottom thereof is an oil reservoir 53 whose cross section perpendicular to the front-rear direction forms a wedge shape. ing. An oil strainer 54 having a long tubular shape is disposed in the oil reservoir 53 with its longitudinal direction coinciding with the front-rear direction. The oil strainer 54 has a suction port 55 at the lower peripheral surface, and a rear end is provided in contact with the partition wall 50.

  Note that the configurations of the crank chamber oil pan 51 and the oil strainer 54 are not limited to those described above, but may be other configurations. The obtained oil can be sucked by the oil strainer 54 more efficiently.

  An oil passage 56 is integrally formed in the mission chamber oil pan 52, and the oil passage 56 extends in the front-rear direction at a central position on the left and right sides of the mission chamber oil pan 52. The oil passage 56 extends forward to the partition wall 50 and communicates with an oil strainer 54 provided in the crank chamber oil pan 51. On the other hand, the rear part extends to the rear end of the oil pan 9 and can communicate with the outside through the drain plug 57. Therefore, when the oil is changed, the oil accumulated in the crank chamber oil pan 51 can be discharged to the outside by removing the drain plug 57. The oil passage 56 branches in the middle of the front-rear direction and extends upward, and communicates with a crank chamber scavenging pump described later.

  The oil pan 9 described above forms the bottom of the crank chamber 20 and the transmission chamber 21, and the crank chamber 20 and the clutch chamber 24 shown in FIG. 5 partitioned by the partition wall 38 do not share the oil pan 9. . Therefore, as shown in FIG. 4, the partition between the crank chamber oil pan 51 forming the bottom of the crank chamber 20 and the bottom 24a of the clutch chamber 24 is blocked by the partition wall 38, and the oil flow is restricted. Oil stored in the pan 51 is less likely to enter the clutch chamber 24.

  FIG. 7 is a VII-VII cross-sectional view of the engine E shown in FIG. 2, and FIG. 8 is a right side view of the left crankcase 10. As shown in FIGS. 7 and 8, an oil pump 60 is provided at the lower portion of the crankcase 8. More specifically, a pump casing 62 is formed integrally with the left crankcase 10 at the lower portion of the partition wall 61 that partitions the crank chamber 20 and the transmission chamber 21 (see also FIG. 4).

  The pump casing 62 has a substantially cylindrical shape with a step whose center axis coincides with the left-right direction and opens on the left side (the clutch chamber 24 side). Three pump rotors are fitted into the pump casing 62, and a pump shaft 63 shared by the rotors is fitted into the shaft core. As a result, as the oil pump 60, a crank chamber scavenging pump 64, a clutch chamber scavenging pump 65, and a feed pump 66 are formed in order from the right side.

  Further, the left end portion of the pump shaft 63 is connected to the left end portion of the balancer shaft 37 by a chain 63a (see FIG. 2), and rotates in conjunction with the balancer shaft 37. In this embodiment, all the pumps are trochoidal.

  An oil suction passage 70 extends downward from the inner peripheral portion of the pump casing 62, and the oil suction passage 70 communicates with an oil passage 56 formed in the oil pan 9. Accordingly, the crank chamber oil pan 51 (see FIG. 6) communicates with the suction port (not shown) of the crank chamber scavenging pump 64 through the oil passage 56 and the oil suction passage 70.

  As shown in FIG. 7, another oil suction passage 71 that is recessed in the diameter increasing direction is formed in the inner bottom portion of the pump casing 62 from the substantially central portion in the left-right direction to the left end portion (see FIG. 4). . As shown in FIG. 4, an oil reservoir 72 that is recessed downward is formed on the inner bottom of the left crankcase 10 and the inner clutch cover 12 and on the extension of the oil suction passage 71 to the left. ing.

  As shown in FIG. 7, the oil reservoir 72 is provided with an oil pipe 73 having an opening at the lower portion of the peripheral surface of the left end, and the right end of the oil pipe 73 communicates with the oil suction path 71. Yes. Accordingly, the clutch chamber 24 communicates with the suction port (not shown) of the clutch chamber scavenging pump 65 through the oil pipe 73 and the oil suction passage 71.

  As shown in FIG. 8, an oil discharge path 74 is formed in the partition wall 61 that partitions the crank chamber 20 and the transmission chamber 21. The oil discharge path 74 extends in the left-right direction from a partition wall 61 provided in the left crankcase 10 to a partition wall 61 (see FIG. 4) provided in the right crankcase 11.

  The oil discharge passage 74 communicates with a discharge port (not shown) of the crank chamber scavenging pump 64 and the clutch chamber scavenging pump 65 shown in FIG. It communicates with the connected oil pipe 75 (see FIG. 3). As shown in FIG. 3, the oil pipe 75 is connected to the lower part of the outer mission cover 17, and communicates with the oil storage chamber 26 (see FIG. 5) from below.

  As shown in FIG. 7, an oil strainer 76 is disposed in the mission chamber oil pan 52, and the oil strainer 76 communicates with the suction port of the feed pump 66 through an oil suction path (not shown). An oil discharge port (not shown) of the feed pump 66 communicates with various parts of the engine E through a main gallery (not shown) formed in the crankcase 8.

  The crank chamber scavenging pump 64, the clutch chamber scavenging pump 65, and the feed pump 66 described above are driven by the pump shaft 63 rotating in conjunction with the balancer shaft 37. The right end of the pump shaft 63 is connected to a water pump 67 through a gear, and the water pump 67 is also driven in conjunction with the balancer shaft 37.

  Thus, each pump is accommodated in the pump casing 62, and each pump 64-66 is driven by one pump shaft 63, so that the three pumps 64-66 can be configured in a compact manner. The score can also be reduced. In addition, you may provide the pump which plays each role independently mutually.

  As shown in FIG. 8, the partition wall 38 that partitions the crank chamber 20 and the clutch chamber 24 is provided with a plurality of ventilation holes 81 around a bearing 80 that supports the crankshaft 30. The vent hole 81 passes through the partition wall 38 and opens toward the generator 39 (see the broken line shown in FIG. 8) disposed in the clutch chamber 24.

  Therefore, gas flows back and forth between the crank chamber 20 and the clutch chamber 24 through the plurality of vent holes 81 in accordance with the pressure fluctuation in the crank chamber 20 caused by the vertical movement of the piston 33. Since the gas that has come and goes is blown to the generator 39, the generator 39 that is relatively hot can be cooled.

  The left crankcase 10 is provided with a vent hole 82 that allows communication between the upper rear end of the clutch chamber 24 and the upper portion of the output shaft chamber 22. The output shaft chamber 22 and the separator chamber 23 are partitioned by a partition wall 83. A vent hole 84 communicating the output shaft chamber 22 and the separator chamber 23 is provided at a central position in the vertical direction of the output shaft chamber 22 in the partition wall 83.

  A plurality of ribs 85 are provided in the separator chamber 23, and the ribs 85 divide the separator chamber 23 into a plurality of small spaces 86 that communicate with each other. A flow hole 87 that communicates with the transmission chamber 21 in the lower portion of the separator chamber 23 is provided in the lower portion of the partition wall 83.

  In addition, a flow hole 88 that communicates with the separator chamber 23 in the lower portion of the output shaft chamber 22 is provided in the lower portion of the partition wall 83. The output shaft chamber 22 communicates with the transmission chamber 21 through the flow holes 87 and 88. Further, a tubular joint 89 is attached to an upper position of the separator chamber 23 in the left crankcase 10, and the separator chamber 23 can communicate with the outside of the crankcase 8 through the joint 89.

  The oil flow in the engine E will be described. FIG. 9 is a schematic diagram for explaining the flow of oil in the engine E. FIG. As shown in FIG. 9, the oil stored in the transmission chamber 21 forming the oil tank is sucked up by the feed pump 66 and is pumped to various places in the engine E through the main gallery 90.

  The pumped oil is filtered by the oil filter 91, and on the one hand, supplied to the crankshaft 30 for lubrication of the sliding contact surface between the crankpin 31 and the connecting rod 32 (see FIG. 5). It is also supplied into the rocker shafts 92 and 93 arranged on the tops of 6 and 7, and used for lubricating the valve train.

  The oil provided for lubrication or the like by the crankshaft 30 subsequently drops in the crank chamber 20 and is collected in an oil reservoir 53 formed in the oil pan 9. The oil used for valve system lubrication then drops through the cylinders 6, 7 or descends along the inner wall of the crankcase 8 forming the crank chamber 20 and is collected in the oil reservoir 53. The oil reservoir 53 is provided in the lower part of the crank chamber 20, and the crank chamber 20 and the clutch chamber 24 are partitioned by the partition wall 38, so that the oil collected in the oil reservoir 53 does not flow out to the clutch chamber 24. Absent.

  The oil collected in the oil reservoir 53 is sucked into the scavenging pump 64 for the crank chamber through the oil strainer 54, the oil passage 56, and the oil suction passage 70 (see FIG. 7), and through the oil discharge passage 74 and the oil pipe 75. It is discharged into the oil storage chamber 26. Further, the oil stored in the oil storage chamber 26 is injected from a plurality of oil injection holes 46 (see also FIG. 5) through the oil passage 42 in the main shaft 40 and the counter shaft 41 to lubricate the transmission 45. Then, it is returned to the transmission chamber 21.

  A relief valve 94 is provided in the middle of the main gallery 90. When the hydraulic pressure in the main gallery 90 exceeds a predetermined reference value, the relief valve 94 is opened and depressurized.

  On the other hand, blow-by gas is generated in the crank chamber 20, and the blow-by gas travels between the crank chamber 20 and the clutch chamber 24 through the vent hole 81 as the piston 33 moves up and down. At this time, part of the oil contained in the blow-by gas flowing into the clutch chamber 24 adheres to the inner wall of the clutch chamber 24. A part of the blow-by gas that has flowed in is separated into gas and liquid, and the liquid oil is collected in an oil reservoir 72 formed in the inner bottom of the clutch chamber 24.

  The oil collected in the oil reservoir 72 is drawn into the clutch chamber scavenging pump 65 through the oil pipe 73 and the oil suction passage 71 (see FIG. 7). The oil sucked into the clutch chamber scavenging pump 65 is discharged to the oil storage chamber 26 through the oil discharge passage 74 and the oil pipe 75 in the same manner as the oil sucked into the crank chamber scavenging pump 64. The oil is returned from the oil injection hole 46 to the transmission chamber 21 through the oil passage 42 in the shaft 40 and the countershaft 41.

  In this manner, the scavenging pumps 64 and 65 for the crank chamber and the clutch chamber are separately provided, and oil in the crank chamber 20 and the clutch chamber 24 is collected by independent routes. Therefore, even in the motorcycle 1 equipped with the engine E having the clutch chamber 24 on the same left side as the side stand 5 as in the present embodiment, the oil in the clutch chamber 24 can be efficiently recovered, 44 can be prevented from being oiled.

  Further, since the crank chamber 20 and the clutch chamber 24 are partitioned by the partition wall 38 and oil flow between the two chambers is restricted, the crank chamber 20 and the clutch chamber 24 adhere to the inner wall of the crank chamber 20 after the engine E is stopped. Oil can be prevented from entering the clutch chamber 24.

  Moreover, since the transmission chamber 21 is used as an oil tank, the space in the transmission chamber 21 can be used effectively, and an increase in engine size can be suppressed. Further, the number of parts and the engine weight can be reduced as compared with the case where an oil tank is provided separately.

  Next, the flow of blow-by gas in the engine E will be described with reference to FIG. As already described, the blow-by gas generated in the crank chamber 20 flows into the clutch chamber 24 through the vent hole 81 provided in the partition wall 38 and is blown to the generator 39 to cool the generator 39, and then the clutch It flows backward in the chamber 24 (see the arrow indicated by the broken line in the figure). The blow-by gas that has flown backward flows into the output shaft chamber 22 from above through a vent hole 82 provided in the rear portion of the clutch chamber 24.

  When flowing into the output shaft chamber 22 from the vent hole 82, the output shaft chamber 22 serves as an expansion chamber, and a part of the blow-by gas is gas-liquid separated. The separated oil component flows into the separator chamber 23 through a flow hole 88 provided in the lower portion of the output shaft chamber 22, and further flows into the transmission chamber 22 through the flow hole 87.

  On the other hand, the remaining blow-by gas flows into the separator chamber 23 through the vent hole 84 provided in the output shaft chamber 22. Since the vent hole 84 is provided at a central position in the vertical direction of the output shaft chamber 22, oil separated in the output shaft chamber 22 is prevented from entering the separator chamber 23 through the vent hole 84. Can do.

  The separator chamber 23 is divided into a plurality of small spaces 86, and the blow-by gas is further separated into gas and liquid in the process of moving through the small spaces 86. As a result, the separated oil component flows to the transmission chamber 22 through a flow hole 87 provided in the lower portion of the separator chamber 23, and the separated gas component passes through the joint 89 and further through a pipe line (not shown) to the intake system ( Air cleaner etc.)

  Thus, the blow-by gas containing the oil component is gas-liquid separated in the output shaft chamber 22 and the separator chamber 23, and the separated oil component is returned to the transmission chamber 21 forming the oil tank. The gas containing a small amount of oil is sent to the intake system, and then sent to a combustion chamber (not shown) of the engine E for combustion.

  In the present embodiment, the engine E is described in which the side stand 5 is on the left side of the vehicle body and the clutch chamber 24 is positioned on the left side of the crank chamber 20, but the side stand is on the right side of the vehicle body and the clutch The present invention can also be applied to an engine whose chamber is located on the right side of the crank chamber.

  In addition, the crank chamber 20, the transmission chamber 21, the output shaft chamber 22, and the separator chamber 23 show the engine E that is integrally formed by the crankcase 8. However, the present invention is not limited to this, and each has an independent configuration. There may be.

  Alternatively, an engine that outputs rotation from the end of the countershaft 41 to the rear wheel 3 via a pulley or sprocket without the output shaft 47 may be used.

  Furthermore, the present invention is not limited to an engine mounted on an American type motorcycle, but may be any other type of motorcycle as long as the engine has a clutch chamber disposed on the same side as the side stand on the vehicle body. It can also be used for engines mounted on the.

  The present invention can be applied particularly to an engine mounted on a motorcycle, and can be applied to various types of motorcycles in addition to the American type.

1 is a left side view of a motorcycle equipped with an engine according to an embodiment of the present invention. FIG. 2 is a left side view of the engine shown in FIG. 1 with a part cut away. FIG. 2 is a right side view of the engine shown in FIG. 1 with a part cut away. It is a disassembled perspective view which shows the main housing components of the engine except a cylinder. FIG. 5 is a VV cross-sectional view of the engine shown in FIG. 2. It is a perspective view of an oil pan. FIG. 3 is a VII-VII cross-sectional view of the engine shown in FIG. 2. It is a right view of a left crankcase. It is a schematic diagram for demonstrating the flow of the oil in the engine which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Motorcycle 5 Side stand 6, 7 Cylinder 8 Crankcase 9 Oil pan 10 Left crankcase 11 Right crankcase 12 Inner clutch cover 13 Outer clutch cover 14 Cam cover 15 Inner mission cover 17 Outer mission cover 20 Crank chamber 21 Transmission chamber 22 Output shaft Chamber 23 Separator chamber 24 Clutch chamber 25 Cam chamber 26 Oil storage chamber 30 Crankshaft 38 Partition 39 Generator 40 Main shaft 41 Countershaft 42 Oil passage 44 Clutch 45 Transmission 46 Oil injection hole 47 Output shaft 51 Crank chamber oil pan 52 Mission chamber Oil pan 53 Oil reservoir 54 Oil strainer 56 Oil passage 60 Oil pump 62 Pump casing 63 Pump Shaft 64 Crank chamber scavenging pump 65 Clutch chamber scavenging pump 66 Feed pumps 70, 71 Oil suction path 72 Oil reservoir 74 Oil discharge path 81 Ventilation hole 90 Main gallery

Claims (5)

A crank chamber for storing the crankshaft;
A clutch chamber that is disposed on the side of the crank chamber and houses a clutch;
A scavenging pump for sucking in oil accumulated at the inner bottom of the crank chamber and the clutch chamber;
A motorcycle engine characterized in that a partition wall is provided between the crank chamber and the clutch chamber so that oil flow between the bottom portions of the crank chamber and the clutch chamber is restricted.   The motorcycle engine according to claim 1, wherein the clutch chamber is disposed on the same side as the side stand with respect to the vehicle body with respect to the crank chamber.   The crankcase pump for sucking oil in the crank chamber and the clutch chamber pump for sucking oil in the clutch chamber are provided separately as the scavenging pump, respectively. The motorcycle engine described.   The engine for a motorcycle according to any one of claims 1 to 3, wherein an oil reservoir is formed in an inner bottom portion of the clutch chamber. A motorcycle equipped with the engine according to any one of claims 1 to 4.