JP2018184885A - Lubrication structure of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lubrication structure of an internal combustion engine which reduces a load of an oil pump while securing supply of lubrication oil to a variable speed gear and achieves a reduction of the capacity of the oil pump and a reduction of a friction loss of the internal combustion engine.SOLUTION: A lubrication structure of an engine 11 includes: a seventh oil passage 77 which returns lubrication oil returned from an oil cooler 33 to a crank case 41; a storage part 79 which stores the lubrication oil flowing out from the seventh oil passage 77 and opens to a variable speed gear chamber 49; and an eighth oil passage 78 serving as a variable speed gear lubrication oil passage which guides the lubrication oil from the storage part 79 to at least one of a shaft end 64a of a counter shaft 64 and a shaft end 65a of a drive shaft 65. The storage part 79 is disposed below the oil cooler 33. The shaft end 64a of the counter shaft 64 and the shaft end 65a of the drive shaft 65 are disposed below the storage part 79.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a lubricating structure for an internal combustion engine.

  A lubrication structure for an internal combustion engine that supplies lubricating oil discharged from an oil pump directly to a shaft end of a main shaft (drive shaft) and a shaft end of a counter shaft is known. (For example, refer to Patent Document 1).

JP 2011-64260 A

  The lubricating oil supplied to the shaft end of the main shaft is supplied to the transmission gear through the through hole of the main shaft. The lubricating oil supplied to the transmission gear lubricates the transmission. The same applies to the lubricating oil supplied to the shaft end of the counter shaft. The lubricating oil that lubricates these transmissions is poured into the through holes of the respective shafts by the discharge pressure of the oil pump.

  By the way, the oil pump supplies lubricating oil to other than the through hole of the drive shaft and the through hole of the counter shaft. Therefore, supplying lubricating oil directly to the through hole of the drive shaft and the through hole of the counter shaft by the discharge pressure of the oil pump increases the load of the oil pump, hinders the reduction of the pump capacity, Preventing the reduction of the capacity, which in turn increases the friction loss of the internal combustion engine.

  Therefore, the present invention provides a lubricating structure for an internal combustion engine capable of reducing the load of the oil pump while ensuring the supply of lubricating oil to the transmission, and reducing the capacity of the oil pump and thus reducing the friction loss of the internal combustion engine. The purpose is to provide.

  In order to solve the above problems, a lubricating structure for an internal combustion engine according to the present invention includes a crankcase having a transmission chamber, a cylinder combined with the crankcase, a cylinder head combined with the cylinder, and a transmission chamber. An internal combustion engine side that is provided on the counter shaft to be accommodated, the drive shaft to be accommodated in the transmission chamber, the crankcase, the cylinder, the cylinder head, the counter shaft, and the drive shaft to distribute lubricating oil An oil passage, an oil cooler for cooling the lubricating oil flowing through the internal combustion engine side oil passage, and a first return oil for returning the lubricating oil cooled by the oil cooler to the internal combustion engine side oil passage in the cylinder The internal combustion engine side oil passage returns from the oil cooler and the cylinder and the A second return oil passage that returns the lubricating oil that has cooled the lender head to the crankcase, a storage portion that stores the lubricating oil that flows out of the second return oil passage, and is opened to the transmission chamber; A transmission lubricating oil passage that guides the lubricating oil from the storage portion to at least one of a shaft end of the counter shaft and a shaft end of the drive shaft, and the storage portion is disposed below the oil cooler. Of the shaft end of the counter shaft and the shaft end of the drive shaft, the shaft end connected to the transmission lubricating oil path is disposed below the storage portion.

  According to the present invention, there is provided a lubricating structure for an internal combustion engine capable of reducing the load of the oil pump while ensuring the supply of the lubricating oil to the transmission, reducing the capacity of the oil pump, and thus reducing the friction loss of the internal combustion engine. Can be provided.

1 is a left side view showing an example of a motorcycle to which a lubricating structure for an internal combustion engine according to an embodiment of the present invention is applied. 1 is a front view showing an internal combustion engine according to an embodiment of the present invention. The left view which shows the internal combustion engine which concerns on embodiment of this invention. 1 is a schematic system diagram of a lubricating structure for an internal combustion engine according to an embodiment of the present invention. 1 is a schematic perspective view of a lubrication system for an internal combustion engine according to an embodiment of the present invention. The right view of the right side case half of the internal combustion engine which concerns on embodiment of this invention. The left view of the right case half of the internal combustion engine which concerns on embodiment of this invention. The right view of the left side case half of the internal combustion engine which concerns on embodiment of this invention. 1 is a partial cross-sectional view of a left case half and a left case cover of an internal combustion engine according to an embodiment of the present invention.

  An embodiment of a lubricating structure for an internal combustion engine according to the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the same or equivalent structure in several drawing.

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

  In the present embodiment, front and rear, top and bottom, and left and right expressions are based on the occupant of the motorcycle 1.

  As shown in FIG. 1, a motorcycle 1 according to this embodiment includes a body frame 2 that extends in the front-rear direction, a front wheel 5 that is disposed in front of the body frame 2, and a front wheel 5 that is disposed at a front end portion of the body frame 2. A steering mechanism 6 that supports the rear wheel 7, a rear wheel 7 that is disposed behind the body frame 2, a swing arm 8 that is disposed at the rear of the body frame 2 and rotatably supports the rear wheel 7, and the body frame 2. And an internal combustion engine 11 (hereinafter simply referred to as “engine 11”). The motorcycle 1 includes a fuel tank 12 that is disposed above the front half of the vehicle body frame 2 and stores fuel supplied to the engine 11, and a seat that is disposed above the rear half of the vehicle body frame 2 and seats a passenger. 13 and a vehicle body cover 15 that covers a part of the vehicle body frame 2.

  The body frame 2 is a so-called cradle type. The vehicle body frame 2 includes a plurality of steel hollow tubes combined together. 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 disposed at the upper front end of the vehicle body frame 2. The head pipe 21 supports the steering mechanism 6 so as to be steerable in the left-right direction of the vehicle.

  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, curves 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 is curved in the middle toward the rear.

  The pair of left and right seat rails 25 branch off from the front end portion connected to the curved portion of the main tube 22 and extend obliquely rearward and upward.

  The pair of left and right seat pillars 26 branch from a front end portion connected to the lower end portion of the main tube 22 and extend obliquely rearward and upward, and merge with an intermediate portion of the length of the seat rail 25 to be seat rail 25. Is supporting.

  The steering mechanism 6 includes a suspension mechanism (not shown) and a pair of left and right front forks 27 that rotatably support the front wheels 5, a front fender 28 that covers the front wheels 5, and a top portion of the front forks 27. And a handle 29 to be fixed.

  The front wheel 5 is sandwiched between the left and right front forks 27 and rotates around an axle that is installed 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 installed 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 wheel 7 and rotates the rear wheel 7.

  The engine 11 is disposed 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 that cools lubricating oil that performs lubrication and cooling of each part of the engine 11 is provided obliquely in front and above the engine 11. The oil cooler 33 is preferably arranged so as to avoid being exposed to the front fender 28 and the front wheels 5 so as to be easily exposed to the traveling wind of the motorcycle 1.

  The fuel tank 12 is supported by the main tube 22 exclusively. The fuel tank 12 swells immediately after the head pipe 21 over 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 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.

  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 part of the fuel tank 12 and 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 rear half of the seat 13 and extends rearward, and extends to the rear of the seat 13 and joins.

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

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

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

  As shown in FIGS. 2 and 3, the engine 11 according to the present embodiment is an internal combustion engine with a small displacement of, for example, 50 cc class or 250 cc class. The engine 11 is a four-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 disposed in the lower half of the engine 11. The crankcase 41 includes an integrated transmission case 45.

  The crankcase 41 includes a left case half 51 and a right case half 52. The crankcase 41 can be divided into left and right. The left and right case halves 51 and 52 are combined at a coupling surface 41 a substantially perpendicular to the rotation center line of the crankshaft 46. In other words, the crankcase 41 has a pair of left and right case halves 51 and 52 that are combined at a coupling surface 41 a that is substantially orthogonal to the rotation center line of the crankshaft 46.

  The crankcase 41 includes a left case cover 53 provided on the left side of the left case half 51 and a right case cover 54 provided on the right side of the right case half 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 upper portion of the crankcase 41 in a forward inclined posture in which the center line of a cylinder bore (not shown), that is, the moving direction of a piston (not shown) is slightly inclined forward.

  The cylinder head 43 is coupled to the top of the cylinder 42 and closes the cylinder 42. An outlet flange 43a of an exhaust port (not shown) is provided in front of the cylinder head 43. An inlet flange 43 b of 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 and closes the cylinder head 43.

  An oil cooler 33 is connected to the engine 11 via oil hoses 56 and 57.

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

  Oil hoses 56 and 57 circulate oil between the engine 11 and the oil cooler 33.

  The oil hose 56 disposed below sends oil from the engine 11 to the oil cooler 33. The oil hose 56 extends from the corner between the front wall and the right side wall of the cylinder 42, and extends to the oil cooler 33 bypassing the front of the cylinder 42. The oil hose 56 is connected to the bottom of the oil cooler 33.

  An oil hose 57 (first return oil passage) disposed above returns oil from the oil cooler 33 to the engine 11. The oil hose 57 extends from the corner between the front wall and the left side wall of the cylinder 42 to the oil cooler 33. The oil hose 57 is connected to the top of the oil cooler 33.

  FIG. 4 is a schematic system diagram of the lubricating 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 58 that is provided in the crankcase 41, the cylinder 42, and the cylinder head 43 and serves as an internal combustion engine side oil passage through which lubricating oil flows. . In other words, the engine 11 is oil-cooled.

  The engine 11 also includes an oil pan 61 that is provided at the bottom of the crankcase 41 and stores lubricating oil.

  The engine 11 supplies the lubricating oil stored in the oil pan 61 to each part of the crankshaft 46, the piston 62, the valve operating mechanism 63, the countershaft 64, and the drive shaft 65 to lubricate and cool them.

  The crankcase 41 has a crank chamber 47 in which the crankshaft 46 is accommodated, and a transmission chamber 49 in which the transmission 48 is accommodated.

  The crankshaft 46 is rotatably supported in the crank chamber 47. The piston 62 is accommodated in a cylinder bore (not shown) of the cylinder 42 so as to be able to reciprocate. The valve mechanism 63 is accommodated in a valve chamber (not shown) of the cylinder head 43. The counter shaft 64 and the drive shaft 65 are accommodated in the transmission chamber 49.

  The oil cooler 33 is disposed above the highest point of the oil passage 58. The oil cooler 33 cools the lubricating oil (not shown) flowing through the oil passage 58. The internal combustion engine lubrication structure includes an oil passage 58 and an oil cooler 33 of the engine 11.

  The oil passage 58 b of the cylinder 42 includes a first oil passage 71 directly connected to the cylinder head 43, a second oil passage 72 connected to the oil cooler 33 via the oil hose 56, and the oil cooler 33 via the oil hose 57. And a third oil passage 73 connected to the cylinder head 43.

  The oil hose 57 is a first return oil passage that returns the lubricating oil cooled by the oil cooler 33 to the oil passage 58 b in the cylinder 42.

  The oil passage 58c of the cylinder head 43 is an exhaust port formed by lubricating oil flowing from the first oil passage 71 of the cylinder 42 to the valve operating mechanism 63 and lubricating oil flowing from the third oil passage 73 of the cylinder 42. And a fifth oil passage 75 that cools the periphery of 66.

  The oil passage 58 b of the cylinder 42 includes a sixth oil passage 76 that circulates the lubricating oil flowing from the fifth oil passage 75 of the cylinder head 43 around the combustion chamber 67, and the lubricating oil from the sixth oil passage 76 into the crankcase 41. And a seventh oil passage 77 (second return oil passage).

  The seventh oil passage 77 is a second return oil passage that returns the lubricating oil that has returned from the oil cooler 33 and cooled the cylinder 42 and the cylinder head 43 to the crankcase 41.

  The oil passage 58a of the crankcase 41 includes a forward path for pumping the lubricating oil from the oil pan 61 and sending it to the oil passage 58b of the cylinder 42, and a return path for returning the lubricating oil from the oil passage 58b of the cylinder 42 to the oil pan 61. It is out.

  The return path portion of the oil passage 58 a of the crankcase 41 includes a storage portion 79 that stores lubricating oil that flows out from the seventh oil passage 77 of the cylinder 42, and an eighth oil passage 78 that is connected to the storage portion 79.

  The reservoir 79 is open to the transmission device chamber 49. Therefore, the lubricating oil in the reservoir 79 overflows from the reservoir 79 to the transmission chamber 49 while filling the reservoir 79 (solid arrow OF in FIG. 4). The lubricating oil overflowing into the transmission chamber 49 lubricates the transmission 48.

  The eighth oil passage 78 is a transmission lubricating oil passage that guides lubricating oil from the reservoir 79 to at least one of the shaft end 64 a of the counter shaft 64 and the shaft end 65 a of the drive shaft 65. The eighth oil passage 78 according to the present embodiment includes a first transmission lubricating oil passage 81 that guides lubricating oil from the storage portion 79 to the shaft end 64 a of the counter shaft 64, and the storage portion 79 to the shaft end 65 a of the drive shaft 65. And a second transmission lubricating oil passage 82 for guiding the lubricating oil.

  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 this embodiment includes an oil pump 85 that sucks lubricating oil from the oil pan 61, and oil that removes foreign matter from the lubricating oil discharged from the oil pump 85. And a filter 86. The oil pump 85 and the oil filter 86 are provided in the forward path portion of the oil passage 58 a of the crankcase 41.

  The oil pump 85 is disposed below the crankshaft 46. The oil pump 85 is driven by an auxiliary machine drive gear (not shown) that is integrally rotated with the crankshaft 46. The output of the oil pump 85 depends on the rotational speed of the crankshaft 46, that is, the rotational speed of the engine 11. That is, the oil pump 85 discharges more lubricating oil as the rotational speed of the engine 11 increases. By driving the oil pump 85, the lubricating oil in the oil pan 61 is sucked into the oil passage 58 a of the crankcase 41. The lubricating oil sucked into the oil passage 58a of the crankcase 41 passes through the oil filter 86 to remove foreign matters.

  The lubricating oil that has passed through the oil filter 86 is cooled by the oil cooler 33 through the second oil passage 72 of the cylinder 42 and the oil hose 56. The lubricating oil cooled by the oil cooler 33 reaches the fifth oil passage 75 of the cylinder head 43 through the oil hose 57 and the third oil passage 73. The lubricating oil that has passed through the fifth oil passage 75 and cooled the exhaust port 66 flows into the sixth oil passage 76 and cools the combustion chamber 67. The lubricating oil that has passed through the sixth oil passage 76 and has cooled the combustion chamber 67 is returned from the seventh oil passage 77 to the crankcase 41.

  Further, the lubricating oil that has been branched by the cylinder 42 and has flowed into the first oil passage 71 climbs up the cylinder 42 to reach the fourth oil passage 74 of the cylinder head 43 and lubricates the valve mechanism 63.

  The lubricating oil returned to the crankcase 41 is stored in the storage unit 79. Part of the lubricating oil stored in the storage part 79 flows out from the storage part 79 to the eighth oil passage 78. The lubricating oil passing through the first transmission lubricating oil passage 81 in the eighth oil passage 78 reaches the shaft end 64 a of the counter shaft 64. The lubricating oil that has reached the shaft end 64 a of the counter shaft 64 flows into a hole extending along the axis of the counter shaft 64, and lubricates the counter gear 88 that is rotatably supported by the counter shaft 64. The lubricating oil that has lubricated the counter gear 88 drops in the transmission chamber 49 and returns to the oil pan 61.

  On the other hand, the lubricating oil passing through the second transmission lubricating oil passage 82 in the eighth oil passage 78 reaches the shaft end 65 a of the drive shaft 65. The lubricating oil that has reached the shaft end 65 a of the drive shaft 65 flows into a hole extending along the axis of the drive shaft 65 and lubricates the drive gear 89 that is rotatably supported by the drive shaft 65. The lubricating oil that has lubricated the drive gear 89 drops in the transmission chamber 49 and returns to the oil pan 61.

  Further, part of the lubricating oil stored in the storage unit 79 overflows from the storage unit 79 and drops directly into the transmission device chamber 49. The lubricating oil dropped in the transmission chamber 49 is applied to the transmission, lubricates the counter gear 88 and the drive gear 89, drops in the transmission chamber 49, and returns to the oil pan 61.

  The oil passage 58 of the engine 11 may include a second reservoir 91 provided in the middle of at least one of the oil hose 57, the seventh oil passage 77, and the eighth oil passage 78. For example, the oil passage 58 according to the present embodiment includes a second reservoir 91 provided in the middle of the seventh oil passage 77. The second reservoir 91 is connected to a ninth oil passage 93 as a magneto cooling passage that guides lubricating oil from the second reservoir 91 to the magnet 92.

  The reservoir 79 of the oil passage 58 is disposed below the oil cooler 33. Therefore, the lubricating oil flowing out from the oil cooler 33 flows down to the storage part 79 through the oil hose 57 and the oil passage 58b of the cylinder 42. In other words, the lubricating oil flowing out from the oil cooler 33 reaches the storage part 79 by the head of the oil cooler 33 and the storage part 79. That is, the oil pump 85 only needs to lift the lubricating oil to the top of the oil cooler 33.

  Further, the shaft end connected to the eighth oil passage 78 among the shaft end 64 a of the counter shaft 64 and the shaft end 65 a of the drive shaft 65 is disposed below the storage portion 79. That is, in the oil passage 58 of the engine 11 according to the present embodiment, the shaft end 64a of the counter shaft 64 connected to the first transmission lubricating oil passage 81 is disposed below the storage portion 79, and the second transmission lubricating oil. A shaft end 65 a of the drive shaft 65 connected to the path 82 is also disposed below the storage portion 79. Therefore, the lubricating oil flowing out from the reservoir 79 flows down to the shaft end 64a of the counter shaft 64 through the first transmission lubricating oil passage 81, and to the shaft end 65a of the drive shaft 65 through the second transmission lubricating oil passage 82. run down. Since the reservoir 79 is released to the transmission chamber 49, the lubricating oil flowing out of the reservoir 79 reaches the shaft end 64a of the counter shaft 64 by the head of the reservoir 79 and the shaft end 64a of the counter shaft 64, The head end 65 a of the drive shaft 65 is reached by the head of the storage portion 79 and the shaft end 65 a of the drive shaft 65. That is, the discharge pressure of the oil pump 85 does not act on the shaft end 64 a of the counter shaft 64 and the shaft end 65 a of the drive shaft 65.

  The reservoir 79 extends over the pair of left and right case halves 51 and 52 and extends in a bowl shape over substantially the entire width, and is opened to the transmission chamber 49.

  The eighth oil passage 78 guides the lubricating oil from one end 79a in the width direction of the reservoir 79 to the shaft end 64a of the counter shaft 64, and from the other end 79b in the width direction of the reservoir 79 to the drive shaft 65. Lubricating oil is guided to the shaft end 65a. That is, the first transmission lubricating oil passage 81 in the eighth oil passage 78 guides the lubricating oil from the left end 79 a of the reservoir 79 to the shaft end 64 a of the counter shaft 64. Of the eighth oil passage 78, the second transmission lubricating oil passage 82 guides the lubricating oil from the right end 79 b of the reservoir 79 to the shaft end 65 a of the drive shaft 65.

  The eighth oil passage 78 is inclined downward over substantially the entire length. That is, the first transmission lubricating oil passage 81 is inclined downward from the left end 79 a of the storage portion 79 toward the shaft end 64 a of the counter shaft 64 over its entire length. The second transmission lubricating oil passage 82 is inclined downward over the entire length from the right end 79 b of the reservoir 79 toward the shaft end 65 a of the drive shaft 65.

  FIG. 6 is a partial right side view of the right case half of the internal combustion engine according to the embodiment of the present invention.

  As shown in FIGS. 5 and 6, the second transmission lubricating oil passage 82 of the engine 11 according to this embodiment includes a groove portion 101 provided on the right side surface of the right case half 52, and a plate member 102 that closes the groove portion 101. , And is partitioned.

  The groove portion 101 is connected to an oil passage hole 103 penetrating from the storage portion 79 in the transmission chamber 49 to the right side surface of the right case half 52. The groove portion 101 bypasses the lower portion of the counter shaft 64 along the journal portion of the counter shaft 64 from the top connected to the oil passage hole 103 and is inclined downward to be the shaft end 65a of the drive shaft 65, here the right shaft end portion. To reach.

  The plate member 102 covers the groove 101 over its entire length, and is fixed to the right side surface of the right case half 52 by an appropriate number of screws 105.

  FIG. 7 is a partial left side view of the right case half of the internal combustion engine according to the embodiment of the present invention.

  FIG. 8 is a partial right side view of the left case half of the internal combustion engine according to the embodiment of the present invention.

  As shown in FIGS. 7 and 8, the engine 11 according to this embodiment includes a counter gear 88 provided on the counter shaft 64.

  The storage part 79 has a wall part 107 which is bent right above the counter gear 88 and whose upper end part 107 a is opened to the transmission device chamber 49. In other words, the storage part 79 has the wall part 107 which has the corner | angular part 107b bent right above the counter gear 88, and the upper end part 107a open | released by the transmission device chamber 49. FIG.

  Lubricating oil in the reservoir 79 overflows from the upper end 107 a of the wall 107 to the transmission device chamber 49, travels along the wall surface of the wall 107, and reaches the corner 107 b. Most of the lubricating oil that has reached the corner 107b drops from the corner 107b and is applied to the tooth surface of the counter gear 88 (solid arrows in FIGS. 7 and 8). The lubricating oil applied to the counter gear 88 is scattered in the transmission device chamber 49 by the rotation thereof, and lubricates each part of the transmission device 48 including the drive gear 89.

  By the way, the lubricating oil stored in the storage part 79 not only overflows directly from the bowl-shaped storage part 79 into the transmission device chamber 49, but also enters the counter gear 88 and the drive gear 89 through the eighth oil passage 78. Supplied.

  The first transmission lubricating oil passage 81 of the eighth oil passage 78 reaches the shaft end 64 a of the counter shaft 64 through the clutch release cylinder 108 provided on the side wall of the left case half 51. The first transmission lubricating oil passage 81 has an oil passage hole 109 that penetrates from the reservoir 79 in the transmission chamber 49 to the clutch release cylinder 108. The oil passage hole 109 is bored in the wall of the left case half 51 and is inclined downward from the storage portion 79 to the clutch release cylinder 108.

  The oil passage hole 103 on the right side of the storage portion 79 and the oil passage hole 109 on the left side of the storage portion 79 are regions A inside the line segment connecting the upper end and the lower end of the bent wall portion 107 of the storage portion 79. It is connected to. This region A is reliably filled with the lubricating oil supplied from the oil cooler 33 side to the storage unit 79 even when the motorcycle 1 is stopped, accelerated, or decelerated. Therefore, even if the lubricating oil overflows from the reservoir 79 opened in a bowl shape, no gas (such as air in the transmission chamber 49) enters the eighth oil passage 78, that is, the drive gear 89. And the counter gear 88 is reliably lubricated.

  FIG. 9 is a partial cross-sectional view of the left case half and the left case cover of the internal combustion engine according to the embodiment of the present invention.

  As shown in FIGS. 5 and 9, the second storage portion 91 of the oil passage 58 of the engine 11 according to this embodiment includes a recess 51 a that is opened on the left side surface of the left case half 51, and the left case cover 53. And a recess 53a that is open to the right side surface. That is, the second storage portion 91 is a space in which the concave portion 51 a opened on the left side surface of the left case half 51 and the concave portion 53 a opened on the right side surface of the left case cover 53 are combined.

  The ninth oil passage 93 extends from the concave portion 53 a of the left case cover 53 of the second storage portion 91 toward the magnet 92. The lubricating oil flowing out from the ninth oil passage 93 to the magnet chamber 111 that houses the magnet 92 wipes the magnet 92 and cools the magnet 92.

  The lubrication structure of the engine 11 according to the present embodiment is disposed below the oil cooler 33, the reservoir 79, disposed below the reservoir 79, and connected to the reservoir 79 via the eighth oil passage 78. The shaft end 64a of the counter shaft 64 and the shaft end 65a of the drive shaft 65 are provided. Therefore, the lubricating structure of the engine 11 can use the head of the lubricating oil in order to supply the lubricating oil to the shaft end 64 a of the counter shaft 64 and the shaft end 65 a of the drive shaft 65. That is, the lubricating structure of the engine 11 is such that the oil pump 85 has a smaller capacity than the case where the oil pump 85 supplies the lubricating oil directly to the shaft end 64a of the counter shaft 64 and the shaft end 65a of the drive shaft 65. Can supply. As a result, the lubricating structure of the engine 11 reduces the friction loss of the engine 11 while ensuring the supply of lubricating oil to the transmission 48.

  Further, the lubrication structure of the engine 11 according to the present embodiment has a storage portion 79 that extends over the left and right case halves 51 and 52 and extends in a bowl shape over substantially the entire width and is opened to the transmission chamber 49. It has. Therefore, the lubrication structure of the engine 11 opens the reservoir 79 widely to the transmission chamber 49 and allows the lubricating oil to flow smoothly from the oil cooler 33 to the reservoir 79 regardless of the discharge pressure of the oil pump 85. Further, the lubricating structure of the engine 11 can secure a sufficient capacity in the storage portion 79. The capacity of the storage unit 79 ensures a stable supply of the lubricating oil that overflows from the storage unit 79 and dripping into the transmission 48 and the lubricating oil supplied to the transmission 48 through the eighth oil passage 78.

  Furthermore, the lubricating structure of the engine 11 according to the present embodiment includes an eighth oil passage 78 that is inclined downward over substantially the entire length. Therefore, the lubrication structure of the engine 11 prevents the air from entering the eighth oil passage 78 and the air from accumulating, and stably lubricates the shaft end 64a of the counter shaft 64 and the shaft end 65a of the drive shaft 65. Supply oil.

  Furthermore, the lubricating structure of the engine 11 according to the present embodiment includes a storage portion 79 that has a wall portion 107 that is bent right above the counter gear 88 and that has an upper end portion 107 a that is open to the transmission chamber 49. Therefore, the lubricating structure of the engine 11 can utilize the lubricating oil overflowing from the storage portion 79 for lubricating the transmission 48. In addition, the lubricating structure of the engine 11 ensures that the lubricating oil remains in the reservoir 79 even when the motorcycle 1 is accelerated or decelerated, and the shaft end 64a of the counter shaft 64 and the shaft end of the drive shaft 65 are Stabilize the supply of lubricating oil to 65a.

  Further, the lubrication structure of the engine 11 according to the present embodiment guides the lubricating oil from one end 79a in the width direction of the reservoir 79 to the shaft end 64a of the counter shaft 64, and the other end in the width direction of the reservoir 79. The lubricating oil is guided from the portion 79b to the shaft end 65a of the drive shaft 65. Therefore, the lubricating structure of the engine 11 can simply and easily arrange the oil passages without crossing or branching the oil passages to the respective shaft ends of the counter shaft 64 and the drive shaft 65.

  Further, the lubrication structure of the engine 11 according to the present embodiment includes a second reservoir 91 provided in the middle of at least one of the oil hose 57, the seventh oil passage 77, and the eighth oil passage 78. Therefore, the lubricating structure of the engine 11 further stabilizes the amount of lubricating oil supplied to the shaft ends of the counter shaft 64 and the drive shaft 65.

  Furthermore, the lubrication structure of the engine 11 according to the present embodiment includes a ninth oil passage 93 as a magneto cooling passage for guiding the lubricating oil from the second reservoir 91 to the magnet 92. Therefore, the lubrication structure of the engine 11 can cool the magnet 92 without increasing the capacity of the oil pump 85.

  Furthermore, the lubricating structure of the engine 11 according to the present embodiment is suitable for an oil-cooled internal combustion engine. Since the oil-cooled internal combustion engine cools each part of the engine 11 with the lubricating oil, the oil pump 85 requires a large capacity, and the own weight of the lubricating oil is effectively used to supply the lubricating oil from the storage part 79 to the front. This contributes to a reduction in the capacity of the oil pump 85.

  Therefore, according to the lubrication structure of the engine 11 according to the present embodiment, the load of the oil pump 85 is reduced while ensuring the supply of the lubricating oil to the transmission 48, and the capacity of the oil pump 85 is reduced. Friction loss can be reduced.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 5 ... Front wheel, 6 ... Steering mechanism, 7 ... Rear wheel, 8 ... Swing arm, 11 ... Internal combustion engine, 11 ... Engine, 12 ... Fuel tank, 13 ... Seat, 15 ... Vehicle 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 ... Crankcase, 41a ... Connection surface, 42 ... Cylinder, 43 ... Cylinder head, 43a ... Outlet flange, 43b ... Inlet flange, 44 ... head cover, 45 ... transmission case, 46 ... crankshaft 47 ... Crank chamber, 48 ... Transmission, 49 ... Transmission chamber, 51 ... Left case half, 51a ... Recess, 52 ... Right case half, 53 ... Left case cover, 53a ... Recess, 54 ... Right case cover, 55 ... Fan, 56, 57 ... Oil hose, 58, 58a, 58b, 58c ... Oil passage, 61 ... Oil pan, 62 ... Piston, 63 ... Valve mechanism, 64 ... Counter shaft, 64a ... Shaft end, 65 ... Drive Shaft, 65a ... shaft end, 66 ... exhaust port, 67 ... combustion chamber, 71 ... first oil passage, 72 ... second oil passage, 73 ... third oil passage, 74 ... fourth oil passage, 75 ... fifth oil Passage, 76 ... sixth oil passage, 77 ... seventh oil passage, 78 ... eighth oil passage, 79 ... reservoir, 79a ... end, 79b ... end, 81 ... first transmission lubricating oil passage, 82 ... Second gearbox Oil passage, 85 ... oil pump, 86 ... oil filter, 88 ... counter gear, 89 ... drive gear, 91 ... second reservoir, 92 ... magneto, 93 ... ninth oil passage, 101 ... groove, 102 ... plate material, 103 DESCRIPTION OF SYMBOLS ... Oil passage hole, 105 ... Screw, 107 ... Wall part, 107a ... Upper end part, 107b ... Corner | angular part, 108 ... Clutch release cylinder, 109 ... Oil passage hole, 111 ... Magneto chamber.

Claims (8)

A crankcase having a transmission chamber;
A cylinder combined with the crankcase;
A cylinder head combined with the cylinder;
A countershaft housed in the transmission chamber;
A drive shaft housed in the transmission chamber;
An internal combustion engine side oil passage that is provided in the crankcase, the cylinder, the cylinder head, the counter shaft, and the drive shaft and distributes lubricating oil;
An oil cooler for cooling the lubricating oil flowing through the internal combustion engine side oil passage;
A first return oil passage for returning the lubricating oil cooled by the oil cooler to the internal combustion engine side oil passage in the cylinder,
The internal combustion engine side oil passage is:
A second return oil passage for returning the lubricating oil that has returned from the oil cooler and cooled the cylinder and the cylinder head to the crankcase;
A reservoir that stores the lubricating oil flowing out of the second return oil passage and is opened to the transmission chamber;
A transmission lubricating oil path that guides the lubricating oil from the reservoir to at least one of the shaft end of the counter shaft and the shaft end of the drive shaft;
The reservoir is disposed below the oil cooler,
The internal combustion engine lubrication structure in which the shaft end connected to the transmission lubricating oil path among the shaft end of the counter shaft and the shaft end of the drive shaft is disposed below the storage portion. The crankcase has a pair of left and right case halves combined at a coupling surface substantially perpendicular to the rotation center line of the crankshaft,
The internal combustion engine lubrication structure according to claim 1, wherein the storage section extends over the pair of left and right case halves and extends in a bowl shape over substantially the entire width and is opened to the transmission chamber. The lubricating structure for an internal combustion engine according to claim 1 or 2, wherein the transmission lubricating oil passage is inclined downward substantially over the entire length. A counter gear provided on the counter shaft;
4. The internal combustion engine lubrication structure according to claim 1, wherein the storage portion has a wall portion that is bent right above the counter gear and has an upper end portion that is open to the transmission device chamber. 5. The transmission lubricating oil path guides the lubricating oil from one end portion in the width direction of the storage portion to the shaft end of the counter shaft, and from the other end portion in the width direction of the storage portion to the drive shaft. The lubricating structure for an internal combustion engine according to any one of claims 1 to 4, wherein the lubricating oil is guided to the shaft end. 6. The device according to claim 1, further comprising a second storage portion provided in the middle of at least one of the first return oil passage, the second return oil passage, and the transmission lubricating oil passage. Internal combustion engine lubrication structure. The lubricating structure for an internal combustion engine according to claim 6, further comprising a magnet cooling oil passage that guides the lubricating oil from the second reservoir to the magneto. The lubricating structure for an internal combustion engine according to any one of claims 1 to 7, wherein the internal combustion engine is an oil-cooled internal combustion engine.

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