JP2008088821A - Oil passage structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil passage structure capable of supplying engine oil to each part of an engine sufficiently in a balanced manner, and of laying out a plurality of oil passage simply and compactly. <P>SOLUTION: The structure is provided with a camshaft oil supply path supplying engine oil around a camshaft from a left crank bearing 36a, a connecting rod oil supply path 48 supplying engine oil around a connecting rod 35 from a right crankshaft bearing 36b, and a generator oil supply path 46 supplying engine oil to a generator 37 via a right case cover 21c. A main oil gallery 76 is branched off to a left bearing oil supply path 42a communicating with the camshaft oil supply path, a right bearing oil supply path 42b communicating with the connecting rod oil supply path 48, and a generator side oil path 44 communicating with the generator oil supply path 46. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an oil passage structure of an engine such as a motorcycle.

Conventionally, in the oil passage structure, an oil passage is formed from both ends of a main oil gallery extending in a crankshaft direction in a crankcase toward each crankshaft (see, for example, Patent Document 1). The engine oil supplied to each crank bearing is supplied around the camshaft via the cylinder and the cylinder head, or is supplied around the connecting rod via the crankshaft.
JP 2001-280111 A

By the way, in the above oil passage structure, the engine oil that has passed through the oil filter enters an oil supply passage provided so as to extend in parallel with the crankshaft, and the crank is connected via an oil passage that extends substantially perpendicularly from the oil supply passage. Supplied to the bearing.
However, the engine oil is supplied not only to the crankshaft bearing but also to various parts such as a generator arranged inside the crankcase cover and a camshaft driven via a cam chain arranged on one side of the cylinder and cylinder head. It is necessary to supply oil in a well-balanced and sufficient manner. Further, there is a demand for a simple and compact layout that can simplify machining of a plurality of oil passages leading to each part such as the generator and the camshaft as much as possible.
Accordingly, the present invention provides an oil passage structure that can supply engine oil to each part of the engine in a well-balanced and sufficient manner, and that can lay out a plurality of oil passages in a simple and compact manner.

  As a means for solving the above-mentioned problems, the invention described in claim 1 includes a crankcase (for example, the crankcase 21 of the embodiment) for supporting a crankshaft (for example, the crankshaft 31 of the embodiment) and a cylinder protruding from the crankcase. (For example, the cylinder 32 of the embodiment), a cylinder head attached to the tip of the cylinder (for example, the cylinder head 33 of the embodiment), a crankcase cover that covers one side of the crankcase (for example, the right case cover 21c of the embodiment), In an oil passage structure of an engine (for example, the engine E of the embodiment) provided with a generator (for example, the generator 37 of the embodiment) disposed inside the crankcase, one crank bearing (for example, the left crank bearing 36a of the embodiment) ) To the camshaft (for example, actual The cam shaft oil supply passage (for example, the cam shaft oil supply passage 120 of the embodiment) for supplying engine oil around the cam shaft 52) of the example and the other crank bearing (for example, the right crank bearing 36b of the embodiment) via the crankshaft. A connecting rod oil supply passage (for example, connecting rod oil supply passage 48 of the embodiment) for supplying engine oil around the connecting rod (for example, the connecting rod 35 of the embodiment), and a generator for supplying the engine oil to the generator via the crankcase cover An oil supply passage (for example, the generator oil supply passage 46 of the embodiment) and a main oil gallery (for example, the main oil gallery 76 of the embodiment) that extends further outward than the respective crank bearings in the crankshaft direction. The oil gallery has a first oil passage (for example, the left bearing in the embodiment) that leads to the camshaft oil supply passage. Oil passage 42a), a second oil passage (for example, the right bearing oil passage 42b of the embodiment) that leads to the connecting rod oil passage, and a third oil passage (for example, the generator-side oil passage of the embodiment) that leads to the generator oil passage. 44).

  According to a second aspect of the present invention, the cylinder has a bolt insertion hole for a stud bolt (for example, the bolt insertion hole 114 in the embodiment) for fastening the cylinder and the cylinder head to the crankcase, and the camshaft. An oil supply path communicates with the cylinder head through the bolt insertion hole from a crank bearing opposite to the cam chain (for example, the cam chain 54 in the embodiment), and a side wall (for example, opposite to the cam chain in the cylinder head) The engine oil is supplied around the camshaft through the oil passage in the head (for example, the longitudinal oil passage 117 in the head and the inclined oil passage 118 in the head in the embodiment) provided in the left side wall 33b of the embodiment. And

  According to a third aspect of the present invention, an oil passage (for example, the oil outflow passage 72 of the embodiment) that communicates with the upstream side of the main oil gallery is disposed close to a water jacket (for example, the cooling water communication passage 74 of the embodiment). It is characterized by being.

  According to a fourth aspect of the present invention, the cam chain and the oil pump drive chain (for example, the chain 85 of the embodiment) are arranged between the generator-side crank bearing (for example, the right crank bearing 36b of the embodiment) and the generator. It is provided in.

  According to the first aspect of the invention, the first oil passage that circulates oil from the main oil gallery around the camshaft, the second oil passage that circulates oil around the connecting rod, and the oil that flows to the generator The third oil passage that branches directly reduces the bending of the oil passage, reduces the passage resistance, increases the amount of oil flow, and supplies engine oil to each part of the engine in a well-balanced manner. Can be laid out easily and compactly. Further, machining for forming a plurality of oil passages can be simplified.

  According to the second aspect of the present invention, a part of the camshaft oil supply passage can be easily formed by using the bolt insertion hole of the cylinder. In addition, by providing the head oil passage in the camshaft oil supply passage on the side wall of the cylinder head, oil supply to the shaft end of the camshaft can be facilitated, and the head oil passage can be laid out simply and compactly. Furthermore, by providing the head oil passage in the camshaft oil supply passage on the side wall opposite to the cam chain in the cylinder head, the head oil passage can be easily formed while avoiding interference with the cam chain and the like.

  According to the invention described in claim 3, since engine oil is cooled by the water jacket on the upstream side of the main oil gallery, engine oil having a relatively low oil temperature can be supplied to each part of the engine. Can be improved.

  According to the fourth aspect of the present invention, since the chains wound around the crankshaft are concentrated on one side, the assembling workability of each chain can be improved and each chain is provided on the generator side. The oil chamber space can be consolidated.

  Embodiments of the present invention will be described below with reference to the drawings. Note that the directions such as front, rear, left and right in the following description are the same as those in the vehicle unless otherwise specified. In the figure, the arrow FR indicates the front of the vehicle, the arrow LH indicates the left side of the vehicle, and the arrow UP indicates the upper side of the vehicle.

  In the scooter type motorcycle 1 that is a low-floor type vehicle shown in FIG. 1, the vehicle body frame F includes a head pipe 13 at the front end, and a front fork 11 and a steering handle 12 that pivotally support the front wheel WF are mounted on the head pipe 13. It is supported so that it can be turned. Also, on the lower side of the rear part of the body frame F, an integral swing type power unit (hereinafter referred to as an engine E) which is a motor of the motorcycle 1 is arranged in the front part and an axle S of the rear wheel WR which is a driving wheel is arranged in the rear part. U (referred to as swing unit) is arranged.

  The lower side of the front part of the swing unit U is supported by the rear part of the vehicle body frame F via the link member 61 so as to be swingable up and down. On the other hand, the rear end portion of the swing unit U is supported by the rear end portion of the vehicle body frame F via a rear cushion 7 that is a shock absorber. The swing unit U can swing up and down together with the rear wheel WR about the link member 61 as a pivot, and constitutes a so-called unit swing type rear suspension.

  The vehicle body frame F includes a pair of left and right upper down frames 14 extending rearward and downward from the head pipe 13, and a pair of left and right extending below the upper down frame 14 and extending rearwardly downward from the head pipe 13 and then bent backward. And a lower down frame 15. The rear portion of the lower down frame 15 is a rear inclined portion 15a that is bent and extended rearward, and the rear end of the upper down frame 14 is joined to the lower side of the rear inclined portion 15a.

  The front end of a pair of left and right seat rails 16 that slopes rearward and upward is joined to the rear portion of the upper down frame 14, and the upper end of the rear slope portion 15 a is joined to the middle portion of the seat rail 16. A bracing support frame 10 is provided between the rear portion of the seat rail 16 and the intermediate portion of the rear inclined portion 15a. The vehicle body frame F is mainly composed of the head pipe 13, the upper down frame 14, the lower down frame 15, the seat rail 16, and the support frame 10.

  The vehicle body frame F is covered with a vehicle body cover 19. A tandem occupant seat 20 is disposed on the rear portion of the vehicle body cover 19 so as to be openable and closable. An article storage box 18 that can store a helmet or the like is disposed below the passenger seat 20 and above the power unit U.

The swing unit U is integrally provided with a front engine E and a rear left power transmission mechanism M.
The engine E is a water-cooled four-stroke OHC single-cylinder engine in which the rotation axis C1 of the crankshaft 31 is aligned in the left-right direction (vehicle width direction). It is projected horizontally (inclined slightly to the front in detail). In the drawing, the symbol C2 indicates the axis of the cylinder portion 22 (cylinder axis).

  Referring also to FIG. 2, the crankcase 21 is divided into left and right case halves 21a and 21b. The left case half 21a of the crankcase 21 is integrally formed with a left case main body 23a that protrudes leftward from the left side of the rear portion and then extends rearward. The left case main body 23a constitutes the transmission case 23 in the power transmission mechanism M together with the left case cover 23b attached to the left side thereof. A right case cover 21c is attached to the right side of the right case half 21b of the crankcase 21, and a generator 37 is provided coaxially with the crankshaft 31 inside the right case cover 21c. In addition, the code | symbol B1 in the figure shows the division surface orthogonal to the left-right direction in the left-right center (cylinder axis line C2 position) of the crankcase 21.

  The power transmission mechanism M includes a belt type continuously variable transmission mechanism 24 that continuously changes the driving force of the engine E, and a gear type (not shown) that decelerates the output of the belt type continuously variable transmission mechanism 24 and outputs it to the axle S. And a speed reduction mechanism. The belt type continuously variable transmission mechanism 24 is accommodated across the transmission case 23, and the gear reduction mechanism is accommodated on the rear right side (in the vehicle width direction) of the transmission case 23. An axle S projects rightward from the gear type reduction mechanism, and a rear wheel WR is attached to the axle S.

The cylinder portion 22 mainly includes a cylinder 32 attached to the front end portion of the crankcase 21, a cylinder head 33 attached to the front end portion of the cylinder 32, and a head cover 33 a attached to the front end portion of the cylinder head 33.
A piston 34 is fitted in the cylinder 32 so as to reciprocate. A small end portion 35 b of a connecting rod 35 is connected to the piston 34 via a piston pin 34, and a large end portion 35 a of the connecting rod 35 is connected to a crank pin 31 e of the crankshaft 31. The left and right journals 31a and 31b of the crankshaft 31 are freely rotatable on the left and right crank bearings 36a and 36b formed by the left and right inner side walls 41a and 41b of the left and right case halves 21a and 21b via metal bearings (plain bearings) 39a and 39b, respectively. Supported by

The rotational power of the crankshaft 31 is transmitted to the axle S via the power transmission mechanism M.
The belt-type continuously variable transmission mechanism 24 of the power transmission mechanism M is formed by winding a V belt 103 around the drive pulley 101 and the driven pulley 102, and with a change in the rotational speed of the crankshaft 31, a reduction ratio for the rotational power is predetermined. Within the range of the stepless change. The drive pulley 101 is disposed coaxially with the crankshaft 31 in the front portion of the transmission case 23, and a driven pulley 102 is disposed behind the drive pulley 101, that is, in the rear portion of the transmission case 23.

  The right side portion of the crankshaft 31 extends further to the right from the right journal 31b to form a generator shaft 31c, and the generator shaft 31c supports the outer rotor 37a of the generator 37 accommodated in the right case cover 21c. The outer rotor 37a has a cup shape opened to the right, and a stator coil 37b supported by the right case cover 21c is disposed in the outer rotor 37a.

  A drive sprocket 51 for driving the camshaft 52 in the cylinder head 33 is provided coaxially on the base end side of the generator shaft 31c. A drive sprocket 82 for driving an oil pump 81 (see FIG. 3) is provided immediately on the left side of the drive sprocket 51. Further, a starter driven gear 37c linked to an engine starting means (not shown) is attached to the right side of the outer rotor 37a of the generator 37 via a one-way clutch 37d.

  The camshaft 52 is disposed in the cylinder head 33 in parallel with the crankshaft 31 (that is, along the left-right direction), and both left and right sides thereof are rotatably supported by the cylinder head 33. A driven sprocket 53 is coaxially provided at the left end of the camshaft 52, and a cam chain 54 is wound around the driven sprocket 53 and the drive sprocket 51 of the crankshaft 31, so that the camshaft 52 is synchronized with the crankshaft 31. Is driven to rotate. A cam chain chamber 55 that houses the cam chain 54 is provided on the right side of the cylinder head 33 and the cylinder 32.

  Inlet and exhaust cams 52a and 52b are arranged in parallel at the left and right intermediate portions of the camshaft 52, and the input ends of the intake side and exhaust side rocker arms 56a and 56b are in contact with the intake and exhaust cams 52a and 52b. When the camshaft 52 is rotationally driven as described above, the rocker arms 56a and 56b swing according to the cam patterns of the intake and exhaust cams 52a and 52b, and the intake and exhaust valves (not shown) are operated to operate the cylinder head 33. Open and close the intake and exhaust ports. In the figure, reference numeral 38 denotes a spark plug.

  The left side portion of the crankshaft 31 extends further leftward from the left journal 31a to form a drive pulley shaft 31d, and the drive pulley shaft 31d supports the drive pulley 101 of the belt-type continuously variable transmission mechanism 24 so as to be integrally rotatable. To do. The drive pulley 101 is positioned on the outer side in the axial direction and is fixed to the drive pulley shaft 31d. The drive pulley 101 is positioned on the inner side in the axial direction and is movable in the axial direction with respect to the drive pulley shaft 31d. And a movable pulley half 101b. A V belt 103 is wound around a V groove 101c formed between the pulley halves 101a and 101b. The movable pulley half 101b is biased toward the side away from the fixed pulley half 101a. A plurality of weight rollers 104 are disposed inside the movable pulley half 101b.

  When the rotation of the drive pulley 101 is stopped (when the rotation of the crankshaft 31 is stopped), the movable pulley half 101b is separated from the fixed pulley half 101a and the width of the V groove 101c is increased to wind the V belt 103. When the drive pulley 101 is rotated (when the crankshaft 31 is rotated), the weight roller 104 is moved to the outer peripheral side by the centrifugal force to move the movable pulley half 101b to the fixed pulley half 101a. And the winding position of the V-belt 103 is defined as the outer peripheral side. As the winding position changes, the winding position of the V-belt 103 in the driven pulley 102 also changes, so that the reduction ratio between the pulleys 101 and 102 changes automatically and continuously.

  A cooling fan 107 is formed on the left side of the drive pulley 101, and the cooling fan 107 rotates with the drive pulley 101 when the engine is driven. Thus, outside air is introduced into the transmission case 23 from the intake port 23e of the intake duct 23c attached to the front right side of the transmission case 23, and the belt type continuously variable transmission mechanism 24 and the like are forcibly cooled. An engine intake passage is provided in the intake duct 23c separately from the transmission cooling air passage.

Here, a cartridge type oil filter 68 is attached to the lower left side of the crankcase 21 (left case half 21a) (see FIG. 1).
As shown in FIG. 3, the oil filter 68 accommodates an element in a bottomed cylindrical case 68a, and the opening of the case 68a is closed with a disk-shaped set plate 68b. It is attached so that the center axis line) extends in the left-right direction (crank shaft direction) and the opening side of the case 68a is opposed to the holder portion 71 of the left side wall 21d of the crankcase 21 (left case half 21a).

  An oil outlet 68d is formed at the center of the set plate 68b, and a plurality of oil inlets 68c are formed around the periphery of the set plate 68b. The oil filter 68 allows the engine oil to flow into the case 68a from each oil inlet 68c, passes the oil from the outside to the inside of the element, filters it, and then flows out of the case 68a from the oil outlet 68d. Reference numeral 69 in the figure denotes an oil sensor for detecting the oil temperature or oil pressure attached to the vicinity of the oil filter 68 on the left side wall 21d of the crankcase 21, and reference numeral 69a in the figure denotes a breather pipe for adjusting the internal pressure of the crankcase 21. Show.

  In the crankcase 21, substantially parallel to the crankshaft 31 (with the crank axis C <b> 1) from the central portion of the holder portion 71 (the portion facing the oil outlet 68 d of the oil filter 68) to the right (right and left inner side). An oil outflow path 72 is formed extending along the left-right direction (substantially in parallel). Further, a nozzle 72a communicating with the oil outflow path 72 protrudes leftward from the center portion of the holder portion 71, and a screw thread on the outer periphery of the nozzle 72a and a screw thread on the inner periphery of the oil outlet 68d are screwed together. By tightening the oil filter 68 itself so as to rotate around its axis, the oil filter 68 is detachably attached to the holder portion 71, and the oil outlet path 72 and the oil outlet 68d are in communication with each other. .

  The holder portion 71 is formed with an annular oil groove 71 a so as to face each oil inlet 68 c of the oil filter 68. A portion of the oil groove 71a faces the discharge port of the oil pump 81 in the left-right direction, and the discharge-side oil passage 73 along the left-right direction is connected to the crankcase 21 so as to connect the oil groove 71a and the discharge port in the shortest direction. Formed inside.

  Inside the lower part of the right case half 21b, the oil pump 81 for circulating engine oil is disposed with its drive shaft 83 extending in the left-right direction. A driven sprocket 84 is coaxially provided on the drive shaft 83 of the oil pump 81, and an endless chain 85 is wound around the driven sprocket 84 and the drive sprocket 82, whereby the oil pump 81 is connected to the crankshaft 31. It is linked to rotate.

  A water pump 86 for circulating engine cooling water is disposed on the lower right side of the right case half 21 b with its drive shaft 87 coaxial with the drive shaft 83 of the oil pump 81. The left end portion of the drive shaft 87 of the water pump 86 is engaged with the right end portion of the drive shaft 83 of the oil pump 81 so as not to be relatively rotatable. When the oil pump 81 is driven, the water pump 86 is similarly driven. Cooling water from the water pump 86 is introduced into the cylinder portion 22 from the left side of the crankcase 21 through the cooling water communication passage 74 straddling the left and right case halves 21a and 21b. The cooling water communication passage 74 is disposed so as to be close to the oil outflow passage 72. Reference numeral 58 denotes a unit side connecting portion for connecting the link member 61 to the lower side of the front portion of the swing unit U.

The suction port of the oil pump 81 is connected to a suction-side oil passage 73a that communicates with the oil pan below the crankcase 21, and the discharge port of the oil pump 81 is connected to the oil inlet 68c of the oil filter 68. A side oil passage 73 is connected.
When the oil pump 81 is driven to rotate, the engine oil stored in the oil pan is sucked into the oil pump 81 through the suction side oil passage 73a formed in the right case half 21b, and The oil discharged from the oil pump 81 flows into the oil groove 71a of the holder portion 71 through the discharge side oil passage 73 straddling the left and right case halves 21a and 21b, and the oil filter 68 through the oil groove 71a. The oil is directly introduced into each of the oil inlets 68c.

  The oil filtered through the oil filter 68 is directly introduced into the oil outflow path 72 from the oil outlet 68d through the nozzle 72a. The oil outflow path 72 is provided so as to straddle the left and right case halves 21a and 21b (specifically, the right end portion reaches the right case half 21b). The right end portion of the oil outflow passage 72 extends over the left and right case halves 21a and 21b in the crankcase 21 via a communication groove 75 provided in the right case half 21b on the dividing surface B1. The main oil gallery 76 extending substantially parallel to the left and right intermediate portions communicates with each other. That is, the oil introduced into the oil outflow passage 72 flows into the left and right intermediate portions of the main oil gallery 76 through the communication groove 75. The communication groove 75 may be formed in the left case half 21a, and may be formed in both the left and right case halves 21a and 21b.

  Left and right both ends of the main oil gallery 76 are connected to left and right bearing oil supply passages 42a and 42b formed in left and right inner walls 41a and 41b forming left and right crank bearings 36a and 36b in the left and right case halves 21a and 21b, respectively. The The left and right bearing oil supply passages 42a and 42b extend substantially orthogonal to the crankshaft 31 (crank axis C1) and communicate with the oil supply grooves 43a and 43b on the inner periphery of the left and right crank bearings 36a and 36b. As a result, the engine oil flowing into the main oil gallery 76 is supplied to the sliding surfaces of the left and right metal bearings 39a and 39b.

The left end portion of the main oil gallery 76 extends leftward from the left inner wall 41a (left crank bearing 36a), and the detection portion of the oil sensor 69 faces the left end portion. On the other hand, a generator-side oil passage 44 that extends substantially parallel to the crankshaft 31 on the right side of the right inner wall 41b (right crank bearing 36b) is connected to the right end portion of the main oy gallery 76. The generator-side oil passage 44 communicates with an in-cover oil passage 45 formed in the right case cover 21c.
The oil passage 45 in the cover is appropriately formed with an oil injection port 45a for the generator 37 inside the right case cover 21c. As a result, part of the oil in the main oil gallery 76 is supplied to the generator 37 via the generator-side oil passage 44 and the in-cover oil passage 45. Hereinafter, the in-cover oil passage 45 may be referred to as a generator oil passage 46.

  Part of the oil supplied to the left crank bearing 36a is a valve operating mechanism in the cylinder head 33 (the valve operating chamber) via a cylinder side oil passage 79 (see FIG. 5) formed in the left case half 21a. To be supplied. The oil in the cylinder head 33 is returned to the oil pan below the crankcase 21 via the cam chain chamber 55 on the right side of the cylinder portion 22. The crankcase 21 and the transmission case 23 are oil-tightly partitioned so that no oil is supplied to the belt type continuously variable transmission mechanism 24. Reference numeral 39c in the figure denotes an oil seal that is disposed adjacent to the outside in the axial direction of the left crank bearing 36a and seals the space between the left crank bearing 36a and the left journal 31a in an oil-tight manner.

  On the other hand, a part of the oil supplied to the right crank bearing 36b includes an oil hole 47a that penetrates the right journal 31b of the crankshaft 31 in the radial direction, an oil hole 47b that penetrates the crank pin 31e in the radial direction, and the oils described above. The holes 47a and 47b are supplied to the sliding surface of the metal bearing on the inner periphery of the large end 35a of the connecting rod 35 through an oil hole 47c that connects the holes 47a and 47b obliquely.

  That is, a connecting rod oil supply passage 48 for supplying engine oil around the connecting rod 35 mainly from the right crank bearing 36b is constituted by the oil holes 47a, 47b, 47c. In addition, annular grooves for oil circulation are formed on the outer periphery of the right journal 31b and the inner periphery of the right metal bearing 39a, respectively. A part of the oil supplied to the large end portion 35 a of the connecting rod 35 is supplied to the sliding surface of the metal bush on the inner periphery of the small end portion 35 b through the connecting rod 35.

As shown in FIG. 4, the oil pump 81 is disposed obliquely below and forward of the crankshaft 31 (crank axis C1) in the right case half 21b. On the left side of the relief port of the oil pump 81, a relief passage 77 extending substantially parallel to the crankshaft 31 is disposed across the left and right case halves 21a and 21b.
Further, as shown in FIG. 5, the holder portion 71 (oil filter 68) is disposed obliquely below and forward of the crankshaft 31 in the left side wall 21d of the left case half 21a. An oil outflow path 72 communicating with the oil groove 71 a of the holder portion 71 is disposed on the left side of the discharge port of the oil pump 81.

  The discharge side oil passage 73, the oil outflow passage 72, the relief passage 77, the main oil gallery 76, and the cooling water communication passage 74 straddling the left and right case halves 21 a and 21 b are obliquely below and forward of the crankshaft 31 in the crankcase 21. Aggregated and arranged. It should be noted that an endless seal member 78 that integrally surrounds the outer periphery of the main oil gallery 76, the oil outlet path 72, and the communication groove 75 on the dividing surface B1 of the left and right case halves 21a and 21b is provided. (See FIG. 5).

  In addition, a reed valve that partitions the space between the arrangement space (crank arrangement space) K of the crankshaft 31 in the crankcase 21 and the oil pan P below the crankcase 21 is obliquely below and rearward of the crankshaft 31 in the left case half 21a. 91 is provided. The reed valve 91 opens and closes appropriately depending on the pressure fluctuation in the crank arrangement space K. That is, when pressure fluctuation occurs in the sealed crank arrangement space K due to the operation of the engine E, the reed valve 91 opens and closes intermittently, and the oil in the crank arrangement space K flows downward, that is, into the oil pan P.

  As shown in FIGS. 6 and 7, a cooling water introduction part 112 as a part of the water jacket 111 (see FIG. 8) in the cylinder 32 is provided below the front end of the left case half 21a. The cooling water introducing portion 112 is connected to the left end portion of the cooling water communication passage 74 and opens to a cylinder mounting surface (a mating surface with the base end of the cylinder 32) T1 in the left case half 21a. The cooling water is introduced into the water jacket 111 surrounding the outer periphery of the cylinder bore in the open deck type cylinder 32 through the cooling water introduction part 112.

  Here, the cooling water introduction portion 112 extends rearward so as to be close to the discharge-side oil passage 73 and the oil outflow passage 72 located at the rear thereof, and enters between the discharge-side oil passage 73 and the oil outflow passage 72. By providing the extending portion 112a that further extends as described above, the cooling performance of the engine oil flowing through the crankcase 21 is improved. The cooling water in the water jacket 111 of the cylinder 32 is introduced into the water jacket of the cylinder head 33 from the tip surface (a mating surface with the base end of the cylinder head 33) T2 of the cylinder 32, and then cooled on the upper right side of the cylinder head 33. The water is returned from the water outlet 113 (see FIG. 9) to the water pump 86 through a radiator (not shown).

  As shown in FIGS. 8 and 9, bolt insertion holes 114 (not shown) for inserting stud bolts extending forward from the crankcase 21 along the cylinder axis C <b> 2 are provided on both the upper and lower left and right sides of the cylinder 32. Similarly, bolt insertion holes 115 corresponding to the respective bolt insertion holes 114 are respectively provided on the upper and lower left and right sides of the cylinder head 33. The cylinder 32 and the cylinder head 33 are integrally fixed to the crankcase 21 by inserting the stud bolts into the bolt insertion holes 114 and 115 and screwing nuts into the bolt insertion holes 114 and 115 from the valve operating chamber side. .

  Referring also to FIG. 10, the cylinder-side oil passage 79 in the left case half 21a opens to the upper left of the cylinder mounting surface T1. On the other hand, on the base end surface of the cylinder 32, a base end side communication groove 116 that connects the upper left bolt insertion hole 114 and the cylinder side oil passage 79 is formed.

  Further, the cylinder head 33 has an in-head longitudinal oil passage 117 extending along the cylinder axis C2 from the base end of the cylinder head 33 to the height of the axis C3 of the camshaft 52 in the vicinity of the upper left bolt insertion hole 115 in the left side wall 33b. It is formed and extends linearly at an angle with respect to the axis C3 when viewed from the cylinder axial direction toward the left cam bearing 121 supporting the left end of the camshaft 52 from the tip of the longitudinal oil passage 117 in the head. An in-head inclined oil passage 118 is formed. The in-head longitudinal oil passage 117 and the in-head inclined oil passage 118 are located on the left side of the cylinder head 33, that is, on the side opposite to the cam chain 54, so that the layout by the cam chain 54 and the driven sprocket 53 is not affected.

  On the front end surface T2 of the cylinder 32, a front end side communication groove 119 that connects the upper left bolt insertion hole 114 and the head side vertical oil passage 117 is formed. Accordingly, a part of the oil supplied to the left crank bearing 36a is a cylinder-side oil passage 79, a base-end side communication groove 116, a bolt insertion hole 114, a tip-side communication groove 119, an in-head vertical oil passage 117, and an inside of the head. After being introduced into the left cam bearing 121 via the inclined oil passage 118 and introduced into the inner space from the left shaft end of the camshaft 52, the sliding space of the valve operating mechanism and the like is suitably passed through the inner space. Supplied.

  That is, the bolt insertion hole 114 at the upper left of the cylinder 32 functions as an in-cylinder vertical oil passage 114a through which engine oil flows to the valve operating mechanism. The cylinder side oil passage 79, the cylinder longitudinal oil passage 114a (bolt insertion hole 114), the head longitudinal oil passage 117, and the head inclining oil passage 118 are mainly moved around the camshaft 52 (moving from the left crank bearing 36a). A camshaft oil supply passage 120 for supplying engine oil to the valve mechanism) is configured (see FIG. 2).

  As described above, the oil passage structure in the above embodiment includes the crankcase 21 that supports the crankshaft 31, the cylinder 32 that protrudes from the crankcase 21, the cylinder head 33 that is attached to the tip of the cylinder 32, and the crankshaft. In an oil passage structure of an engine E that includes a right case cover 21c that covers one side of the case 21 and a generator 37 that is arranged inside the crankcase 21, the left crank bearing 36a through the cylinder 32 and the cylinder head 33 are used. A camshaft oil supply passage 120 for supplying engine oil around the camshaft 52, a connecting rod oil supply passage 48 for supplying engine oil around the connecting rod 35 through the crankshaft 31 from the right crank bearing 36b, and the right case cover 21c. Through the di A generator oil supply passage 46 for supplying engine oil to the nebula 37; and a main oil gallery 76 extending further outward than the respective crank bearings 36a, 36b in the crankshaft direction. It branches into a left bearing oil passage 42 a that leads to the camshaft oil passage 120, a right bearing oil passage 42 b that leads to the connecting rod oil passage 48, and a generator side oil passage 44 that leads to the generator oil passage 46.

  According to this configuration, the left bearing oil supply passage 42a that distributes oil from the main oil gallery 76 to the periphery of the camshaft 52, the right bearing oil supply passage 42b that distributes oil around the connecting rod 35, and the oil to the generator are distributed. Since the generator-side oil passage 44 directly branches, it is possible to reduce the flow resistance by reducing the bending of the oil passage, to increase the amount of oil circulation, and to supply engine oil to each part of the engine in a well-balanced manner. Oil passage can be easily and compactly laid out. Further, machining for forming a plurality of oil passages can be simplified.

  In the oil passage structure, the cylinder 32 has a bolt insertion hole 114 for a stud bolt that fastens the cylinder 32 and the cylinder head 33 to the crankcase 21, and the camshaft oil supply passage 120 The left crank bearing 36a on the opposite side of the chain 54 communicates with the cylinder head 33 through the bolt insertion hole 114, and the longitudinal in-head provided on the left side wall 33b of the cylinder head 33 on the opposite side of the cam chain 54 is provided. Engine oil is supplied around the camshaft 52 via an oil passage 117 and an in-head inclined oil passage 118.

  According to this configuration, a part of the camshaft oil supply passage 120 can be easily formed using the bolt insertion hole 114 of the cylinder 32. Further, by providing the in-head vertical oil passage 117 and the in-head inclined oil passage 118 in the cam shaft oil supply passage 120 on the left side wall 33b of the cylinder head 33, oil supply to the shaft end of the camshaft 52 can be facilitated, and The vertical oil passage 117 and the in-head inclined oil passage 118 can be laid out easily and compactly. Further, by providing the in-head vertical oil passage 117 and the in-head inclined oil passage 118 in the cam shaft oil supply passage 120 on the left side wall 33b on the opposite side of the cam chain 54 in the cylinder head 33, interference with the cam chain 54 and the like is avoided. Thus, the in-head longitudinal oil passage 117 and the in-head inclined oil passage 118 can be easily formed.

  Further, in the oil passage structure, the oil outflow passage 72 leading to the upstream side of the main oil gallery 76 is disposed in the vicinity of the cooling water communication passage 74, so that the engine oil flows upstream of the main oil gallery 76. Since it is cooled by the cooling water communication passage 74, engine oil having a relatively low oil temperature can be supplied to each part of the engine, and the engine cooling performance can be improved.

  Further, the oil passage structure is configured such that the cam chain 54 and the oil pump drive chain 85 are provided between the right crank bearing 36b on the generator 37 side and the generator 37, so that each of the oil passage structures is wound around the crankshaft 31. Since the chains 54 and 85 are concentrated on one side, the assembling workability of the chains 54 and 85 can be improved, and the oil chamber space can be concentrated by providing the chains 54 and 85 on the generator 37 side. .

  The present invention is not limited to the above-described embodiment, and can be applied to, for example, an engine other than a unit swing type, a multi-cylinder engine, or a DOHC engine, and a motorcycle, a three-wheeler, or a four-wheel vehicle other than a scooter. Of course, various changes can be made without departing from the scope of the invention.

1 is a left side view of a motorcycle according to an embodiment of the present invention. FIG. 3 is a developed sectional view of the engine of the motorcycle. It is an expanded sectional view of the other cut end of the above-mentioned engine. It is a left view of the right crankcase half of the engine. It is a right view of the left crankcase half of the engine. It is A arrow directional view in FIG. It is AA sectional drawing in FIG. It is an arrow line view which follows the cylinder axis line of the cylinder of the said engine. It is an arrow line view which follows the cylinder axis line of the cylinder head of the engine. It is AA sectional drawing in FIG.

Explanation of symbols

1 Motorcycle (saddle-ride type vehicle)
21 Crankcase 21c Right case cover (Crankcase cover)
31 Crankshaft (Crankshaft)
32 Cylinder 33 Cylinder head 33b Left side wall (side wall)
35 Connecting rod 36a Left crank bearing (one crank bearing)
36b Right crank bearing (the other crank bearing, generator side crank bearing)
37 Generator
42a Left bearing oil supply passage (first oil passage)
42b Right bearing oil supply passage (second oil passage)
44 Generator side oil passage (third oil passage)
46 Generator oil supply passage 48 Connecting rod oil supply passage 52 Cam shaft (cam shaft)
54 Cam chain 72 Oil outflow path (oil passage)
74 Cooling water passage (water jacket)
76 Main oil gallery 85 Chain (oil pump drive chain)
114 Bolt insertion hole 117 Vertical oil passage in the head (oil passage in the head)
118 In-head inclined oil passage (head oil passage)
120 Camshaft oil supply passage E Engine

Claims (4)

A crankcase that supports the crankshaft, a cylinder that protrudes from the crankcase, a cylinder head that is attached to the tip of the cylinder, a crankcase cover that covers one side of the crankcase, and a generator that is disposed inside the crankcase In the oil passage structure of the engine comprising
A camshaft oil supply passage that supplies engine oil around the camshaft from one crankshaft via the cylinder and cylinder head, and a connecting rod oil supply passage that supplies engine oil from the other crankshaft around the connecting rod via the crankshaft A generator oil supply passage for supplying engine oil to the generator via the crankcase cover, and a main oil gallery extending further outward than the crank bearings in the crankshaft direction, The oil passage is characterized in that the gallery branches into a first oil passage that leads to the camshaft oil passage, a second oil passage that leads to the connecting rod oil passage, and a third oil passage that leads to the generator oil passage. Construction. The cylinder has a bolt insertion hole for a stud bolt that fastens the cylinder and the cylinder head to the crankcase, and the camshaft oil supply passage extends from the crankshaft bearing opposite to the cam chain through the bolt insertion hole. The engine oil is supplied to the periphery of the camshaft through an oil passage in the head that communicates with the cylinder head and is provided on a side wall of the cylinder head opposite to the cam chain. The oil passage structure described. The oil passage structure according to claim 1 or 2, wherein an oil passage leading to an upstream side of the main oil gallery is disposed in the vicinity of the water jacket. The oil passage structure according to any one of claims 1 to 3, wherein the cam chain and the oil pump drive chain are provided between a crank bearing on the generator side and a generator.

Images