JP2008088822A - Oil passage structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil passage structure reducing man-hour and cost for assembly while securing the sealing performance of each oil passage on a division plane of a crankcase, and easily making each oil passage communicate with one another while avoiding enlargement of an engine. <P>SOLUTION: An oil outflow passage 72 and a main oil gallery 76 respectively extended across the division plane of the crankcase substantially in parallel with a crankshaft are provided, a communicating groove 75 that connects the oil outflow passage 72 and the main oil gallery 76 is formed on the division plane of at least one divided body (a left case half 21a) of the crankcase, and on a section to which the oil outflow passage 72, the main oil gallery 76 and the communicating groove 75 are opposite on the division plane, an endless sealing member 78 that integrally surrounds the peripheries of them is provided. <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, when the oil passages divided by the dividing surface of the crankcase are connected to each other, they are connected in a sealed state using a collar and a seal member (see, for example, Patent Document 1). ).
JP 2001-342816 A

By the way, when there are two oil passages divided by the dividing surface of the crankcase, it is necessary to provide a separate communication passage when these oil passages are communicated with each other, which complicates the engine to secure the oil passage. At the same time, there is a problem that it is easy to increase the size and the number of man-hours for processing the communication path increases. In addition, two sealing members for sealing the divided surfaces are required, and there is a problem that the number of assembling steps and costs associated therewith increase.
Therefore, the present invention reduces the assembly man-hours and costs while ensuring the sealability of each oil passage on the split surface of the crankcase, and can easily connect each oil passage while avoiding the enlargement of the engine. Provide structure.

  As a means for solving the above problem, the invention described in claim 1 is an engine in which a crankcase (for example, the crankcase 21 of the embodiment) that supports the crankshaft (for example, the crankshaft 31 of the embodiment) is divided in the crankshaft direction. In the oil passage structure of the engine E (for example, the engine E of the embodiment), the first and second oil passages (for example, the embodiment) that extend substantially parallel to the crankshaft across the dividing surface of the crankcase (for example, the dividing surface B1 of the embodiment). An oil outflow passage 72 and a main oil gallery 76) of the example are provided, and the oil passages are connected to each other on the dividing surface of at least one divided body of the crankcase (for example, the left case half 21a of the embodiment). A communication groove (for example, the communication groove 75 of the embodiment) that communicates is formed, and the oil passage and the communication groove on the divided surface face each other. , Characterized in that said oil passage and surrounding integrally with the outer periphery of the communication groove endless sealing member (seal member 78 of the example embodiment) is provided.

  According to a second aspect of the present invention, a cartridge type oil filter (for example, the oil filter 68 of the embodiment) is attached to a side surface of the crankcase, and the first oil passage is an oil outlet of the oil filter. The second oil passage communicates with a crank bearing of the crankcase (for example, each of the crank bearings 36a and 36b of the embodiment).

  According to the first aspect of the present invention, when sealing the divided portions of the divided surfaces of the respective oil passages, the oil passages are integrally sealed together with the communication groove by one endless sealing member. Assembling man-hours and costs can be reduced while ensuring the sealing performance on the divided surfaces. In addition, each oil passage can be easily communicated simply by forming a communication groove on the split surface of the crankcase, so that the oil passage structure can be simplified and the layout freedom of each oil passage can be improved, and the engine can be enlarged. While avoiding, the man-hour for processing a communicating path can be reduced.

  According to the second aspect of the present invention, when the oil inlet of the oil filter is disposed so as to face the discharge port of the oil pump, it communicates with the first oil passage communicating with the oil outlet of the oil filter and the crankshaft. Although the second oil passage as the main oil gallery may be shifted from the main oil gallery, each oil passage can be easily communicated even in such a case, so that an efficient oil passage structure can be formed and each oil passage can be formed. Layout flexibility can be improved.

  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.

  Here, as shown in FIG. 6, the outer circumferences of the main oil gallery 76, the oil outflow path 72, and the communication groove 75 are integrally surrounded on the dividing surface B <b> 1 of the left and right case halves 21 a and 21 b. A single endless seal member 78 is provided. That is, the seal member 78 surrounds the outer periphery of the communication portion including the main oil gallery 76, the oil outflow path 72, and the communication groove 75 on the dividing surface B1, and the left and right case halves 21a and 21b are assembled together. In this case, the communication part can be easily and reliably sealed.

  Referring also to FIG. 7, the divided portions of the main oil gallery 76 and the oil outflow passage 72 at the dividing plane B1 are connected via collars 76c and 72c, respectively. A portion along the outer periphery of the communication portion in the left case half 21a is a recess facing the seat, and a seal member 78 is fitted and positioned in a groove formed by the recess and the outer periphery of each collar. Further, on both sides in the width direction of the communication groove 75, walls 75a extending in the longitudinal direction are projected, and a seal member 78 is fitted and positioned in a groove formed by each wall 75a and the recess. On the other hand, the outer periphery of the communication part in the right case half 21b is a flat sealing surface having no irregularities. The divided portions of the discharge side oil passage 73, the cooling water communication passage 74, and the relief passage 77 at the dividing surface B1 are connected through the collars 73c, 74c1, and 77c, respectively, and are provided on the outer periphery of the collar. Seal members (O-rings) 73d, 74d1, and 77d (see FIGS. 3, 5, and 6).

  As shown in FIG. 3, left and right bearing oil supply passages formed in the left and right inner side walls 41a and 41b forming the left and right crank bearings 36a and 36b in the left and right case halves 21a and 21b at the left and right ends of the main oil gallery 76, respectively. 42a and 42b are connected respectively. 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.
Here, in the divided surface (mating surface) orthogonal to the left-right direction between the right case half 21 and the right case cover 21c, the divided part of the generator side oil passage 44 and the in-cover oil passage 45 is a collar 44c. And a seal member (O-ring) 44d provided on the outer periphery of the collar. The divided portion of the cooling water communication passage 74 on the dividing surface is connected via a collar 74c2 and sealed by a seal member (O-ring) 74d2 provided on the outer periphery of the collar.

  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.

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.

  As shown in FIGS. 6 and 8 (a), an arrangement space (crank arrangement space) K of the crankshaft 31 in the crankcase 21 and the oil pan described above are obliquely below and rearward of the crankshaft 31 in the left case half 21a. A reed valve 91 for partitioning with P is provided. The reed valve 91 has a substantially horizontal flat plate shape. The reed valve 91 has a frame plate 92 having a rectangular communication hole 92a at the center, an elastic plate 93 having one side fixed to the lower surface of the frame plate 92, and the frame plate 92. And a seal member 94 that covers the outer periphery of the first member.

  The elastic plate 93 has a rectangular shape larger than the communication hole 92 a, and the short side portion on the front side is fixed to the frame plate 92 with a pair of screws 95. The elastic plate 93 closes the communication hole 92a when no load is applied and when a load is input from below, and bends downward when a load is input from above to open the communication hole 92a. Thus, as the internal pressure of the crank arrangement space K changes due to the reciprocating movement of the piston 34, the reed valve 91 opens and closes appropriately to reduce friction, and the engine oil in the crank arrangement space K is circulated into the oil pan P. Make it possible.

  The left partition wall 96a that partitions between the crank arrangement space K and the oil pan P in the left case half 21a is provided with a U-shaped notch 97 that opens to the side of the dividing surface B1. The inner periphery of the notch 97 has a U-shaped cross section that opens toward the inside of the notch 97, and the seal member 94 on the outer periphery of the reed valve 91 is held in a sealed state on the inner periphery. One side of the reed valve 91 faces the dividing surface B1, and one side of the right partition wall 96b of the right case half 21b contacts the one side in a sealed state.

  Incidentally, the reed valve 91 has a substantially rectangular shape when viewed from above, and the pair of corners on the back side of the notch 97 is chamfered into an arc having a relatively large radius with respect to the pair of corners on the divided surface B1 side. Is done. Further, in each corner portion on the back side of the cutout portion 97 of the reed valve 91, the rear corner portion is chamfered into an arc having a larger radius than the front corner portion. This prevents erroneous assembly such as changing the orientation of the reed valve 91 when the flat reed valve 91 is assembled to the crankcase 21.

  The vertical width of the elastic plate 93 fixing portion on the rear side of the reed valve 91 (the vertical height of each screw 95) is wider than the vertical width inside the U-shaped cross section in the inner peripheral portion of the notch 97, and The depth of the U-shaped cross section on the rear side of the notch 97 is set deeper than the depth of the U-shaped cross section on the front side of the notch 97. As a result, as shown in FIG. 8B, even if the lead valve 91 is installed in the notch 97 with the front and rear being different, the screws 95 interfere with the inner peripheral part on the rear side of the notch 97. The reed valve 91 cannot be misassembled as described above.

  As described above, the oil passage structure in the above-described embodiment is the oil passage structure of the engine E in which the crankcase 21 that supports the crankshaft 31 is divided in the crankshaft direction and straddles the dividing surface B1 of the crankcase 21. And an oil outflow passage 72 and a main oil gallery 76 that extend substantially parallel to the crankshaft 31, and on the split surface B1 of at least one split body (left case half 21 a) of the crankcase 21, A communication groove 75 that connects the oil outflow path 72 and the main oil gallery 76 to each other is formed, and the oil outflow path 72 is formed at a portion of the dividing surface B1 facing the oil outflow path 72, the main oil gallery 76, and the communication groove 75. And the outer periphery of the main oil gallery 76 and the communication groove 75 are integrated. In which no endless sealing member 78 is provided.

  According to this configuration, when the oil outlet path 72 and the divided part of the main oil gallery 76 at the dividing surface B1 are sealed, these are integrally sealed together with the communication groove 75 by the one endless seal member 78. Further, it is possible to reduce the number of assembling steps and costs while ensuring the sealing performance at the dividing surface B1 of the oil outflow passage 72 and the main oil gallery 76. Further, since the oil outflow passage 72 and the main oil gallery 76 can be easily communicated simply by forming the communication groove 75 on the split surface B1 of the crankcase 21, the oil passage structure can be simplified and the degree of freedom in layout of each oil passage can be achieved. Can be improved, and an increase in the size of the engine can be avoided, and the man-hours for processing the communication path can be reduced.

  In the oil passage structure, a cartridge type oil filter 68 is attached to a side surface of the crankcase 21, and the oil outflow path 72 communicates with an oil outlet 68 d of the oil filter 68. An oil gallery 76 communicates with each crank bearing 36a, 36b of the crankcase 21.

  According to this configuration, when the oil inlet 68c of the oil filter 68 is disposed so as to oppose the discharge outlet of the oil pump 81, the oil outlet 72 communicating with the oil outlet 68d of the oil filter 68 and the crank bearings 36a, The main oil gallery 76 communicating with 36b may be displaced from the main oil gallery 76. Even in such a case, the oil outflow passage 72 and the main oil gallery 76 can be easily communicated with each other, so that an efficient oil passage structure can be formed. At the same time, the degree of freedom in layout of each oil passage can be improved.

  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 principal part enlarged view in FIG. It is AA sectional drawing in FIG. FIG. 7 is a cross-sectional view taken along the line B-B in FIG. 6, where (a) shows a properly assembled state of the reed valve, and (b) shows a misassembled state of the reed valve.

Explanation of symbols

1 Motorcycle (saddle-ride type vehicle)
21 Crankcase 21a Left case half (one split body)
21b Right case half 31 Crankshaft (Crankshaft)
36a Left crank bearing (crank bearing)
36b Right crank bearing (crank bearing)
68 Oil filter 72 Oil outflow passage (first oil passage)
75 Communication groove 76 Main oil gallery (second oil passage)
78 Seal member E Engine B1 Split surface

Claims (2)

In the oil passage structure of the engine in which the crankcase that supports the crankshaft is divided in the crankshaft direction,
A first oil passage and a second oil passage extending substantially parallel to the crankshaft straddling the split surface of the crankcase, and each oil passage is provided on the split surface of at least one split body of the crankcase. A communication groove that communicates with each other is formed, and an endless seal member that integrally surrounds the outer periphery of the oil passage and the communication groove is provided at a portion where the oil passage and the communication groove face on the dividing surface. And oil passage structure. A cartridge type oil filter is attached to a side surface of the crankcase, the first oil passage communicates with an oil outlet of the oil filter, and the second oil passage communicates with a crank bearing of the crankcase. The oil passage structure according to claim 1, wherein the oil passage structure is in communication.

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