JP2018168978A - Connecting rod large end part lubrication structure of internal combustion engine - Google Patents

Abstract

To provide a connecting rod large end part lubrication structure of an internal combustion engine including a side plate capable of reducing assembly man-hour because of easiness of assembly, improving assemblability, reducing its weight, reducing costs, improving sealability, and improving oil storage property.SOLUTION: A connecting rod large end part lubrication structure of an internal combustion engine 4 is configured such that on a web outside surface 78 of a crank web 73R, an annular side plate 100 inserting a crank journal part 77R is provided to define a lubrication oil chamber 110, wherein the side plate has a stationary part 101 with an O-shaped cross section provided on a cross section of an outer peripheral edge along a crank shaft core C, and a tabular oil storage part 105 extending from the stationary part toward the crank shaft core, and is integrally molded with a synthetic resin material.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a side plate in a connecting rod large end lubricating structure of an internal combustion engine.

As a conventional connecting rod large end lubrication structure of an internal combustion engine, an oil passage formed between an outer surface of a ball bearing supporting a crank journal and a crankcase, and an oil groove formed on an outer peripheral surface of the crank journal portion, A crank web connected to the crank journal portion and an oil sump constituted by a side plate attached to the outer surface of the crank web, and the lubricating oil discharged from the oil pump is guided to the oil passage and the oil groove For example, Japanese Patent Application Laid-Open No. H10-228707 discloses a method of lubricating the connecting rod large end portion from the oil reservoir through the hollow portion of the crank pin.
However, in the one shown in the following Patent Document 1, since the side plate assembled to the crankshaft for refueling the connecting rod large end is a metal plate, a press-fitting machine is required at the time of assembly, and the roll force Increasing assembly man-hours, such as adding tightening work, and high costs are likely to occur due to the construction of a solid structure.

JP 2000-310214 A (FIGS. 2 and 3)

  The present invention has been made in view of the above prior art, and is a side plate that is easy to assemble, reduces assembly man-hours, improves assembly, reduces weight, reduces cost, improves sealability, and improves oil storage. It is an object of the present invention to provide a connecting rod large end lubricating structure for an internal combustion engine.

In order to solve the above-described problems, the present invention provides a connecting rod large end portion of an internal combustion engine in which a lubricating oil chamber is defined by including an annular side plate that passes through a crank journal portion on an outer surface of a crank web. In the lubrication structure,
The side plate has a fixed portion having an O-shaped cross section on the cross section along the crank shaft center of the outer peripheral edge, and a plate-shaped oil reservoir plate-shaped portion extending from the fixed portion toward the crank shaft center. A connecting rod large end lubricating structure for an internal combustion engine, which is integrally formed of a resin material.

  According to the above configuration, the side plate is made of synthetic resin, so it has elasticity and flexibility compared to the conventional metal plate side plate, making assembly easier, reducing man-hours, improving assembly, and weight. Reduction, cost reduction, improvement in sealing performance, and improvement in oil storage are achieved, and resonance noise of the side plate due to vibration of the crankshaft during operation of the internal combustion engine is prevented.

In the above configuration,
The side plate includes the fixed portion having a cross-sectional radius of the inner peripheral surface of the connecting portion from the fixed portion having an O-shaped outer peripheral edge to the oil reservoir plate-shaped portion along the crankshaft. You may comprise larger than the radius on the cross section which follows the crankshaft center.
According to its configuration,
When assembling the fixed portion having an O-shaped cross section at the outer peripheral edge, it is difficult for strain to be transmitted to the oil storage plate-like portion due to the contraction force received by the oil storage plate-like portion, and warping of the oil storage plate-like portion can be prevented. The oil reservoir plate-like portion can be formed thinner.

In the above configuration,
The oil reservoir plate-like portion may be displaced in the crankshaft direction with respect to the fixed portion, and the connecting portion may be connected to the inner peripheral side of the fixed portion in the radial direction of the crankshaft.
According to its configuration,
The vibration of the oil storage plate-like part during operation of the internal combustion engine can reduce the influence on the surrounding fixed part fitted into the crank web, reduce the tightening allowance, and reduce the assemblability with the increase of the tightening allowance. Can be prevented.

In the above configuration,
An outer peripheral surface of the crank web is provided with an annular mounting groove facing inwardly in the crankshaft radial direction and an inner peripheral annular protrusion on the outer side in the crankshaft direction. You may comprise so that it may be hold | maintained with an elastic state with respect to an attachment groove | channel, and may be latched by the said annular convex part.
According to its configuration,
Both side plate assembly and weight reduction are compatible.

In the above configuration,
The plate-like portion outer surface of the oil reservoir plate-like portion may be configured to be positioned within the range of the annular convex portion in the crankshaft direction.
According to its configuration,
By preventing the side plate from protruding from the end surface in the crank shaft direction of the crank web, the side plate can be protected.

In the above configuration,
The oil reservoir plate-like portion may include a plurality of oil reservoir ribs formed radially with respect to the crankshaft on a surface facing the crank web.
According to its configuration,
Machine dust once collected because oil wear ribs can be stored in the lubricating oil chamber formed between the outer surface of the crank web and the side plate using the oil storage ribs. It is possible to reduce wear powder and the like from entering the connecting rod for a long time.

In the above configuration,
The side plate may be configured such that the fixed portion occupies at least 30% by weight with respect to the entire side plate.
According to its configuration,
The rigidity and fitting strength of the fixed portion can be obtained, and both the retaining effect and the assembling property can be achieved.

In the above configuration,
The synthetic resin material may be a glass fiber-containing nylon resin.
According to its configuration,
Strength can be obtained while suppressing the cost of the side plate.

According to the connecting rod large end lubricating structure of the internal combustion engine of the present invention,
Compared to the conventional side plate made of metal plate, the side plate is made of synthetic resin, so it has elasticity and flexibility, easy assembly, reduced man-hours, improved assembly, weight reduction, cost reduction, seal And the oil storage performance are improved, and the resonance noise of the side plate due to the vibration of the crankshaft during operation of the internal combustion engine is prevented.

1 is a schematic left side view of a motorcycle provided with a connecting rod large end lubricating structure for an internal combustion engine according to an embodiment of the present invention. FIG. 2 is a right side view of the power unit in FIG. It is a principal part expanded development view of the power unit by the III-III arrow in FIG. FIG. 4 is an elevational cross-sectional view including a crankshaft of the power unit, taken along line IV-IV in FIG. 2. FIG. 4 is an enlarged view around the center of the crankshaft in FIG. 3. (A) part is sectional drawing which takes out the side plate of FIG. 3, FIG. 5 and shows it with the same orientation, (b) part is an expanded sectional view of the fixing | fixed part periphery of the outer edge part of the side plate of (a) part And shows a state where the fixed portion is fitted into the right crank web. (A) part is sectional drawing of the modification of a side plate shown by the same orientation as FIG. 6 (a) part, (b1) part and (b2) part are b1-b1 arrows in (a) part. It is a left view of the modification of a side plate by a view, b2-b2 arrow view. (A) part-(c) part is explanatory drawing of the modified example of the assembly | attachment structure of the side plate shown by the orientation similar to FIG.6 (b) part, and the reference example different from this invention.

A connecting rod large end lubricating structure for an internal combustion engine according to an embodiment of the present invention will be described with reference to FIGS.
In the description and claims of the present specification, the directions such as front, rear, left, right, up, down, etc. refer to a vehicle in a state where the internal combustion engine provided with the connecting rod large end lubrication structure of the internal combustion engine according to the present embodiment is mounted on the vehicle. Follow the direction. In this embodiment, the vehicle is a straddle-type vehicle, specifically a scooter type motorcycle (hereinafter simply referred to as “motorcycle”).
In the figure, an arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

FIG. 1 to FIG. 8 relate to one embodiment of the present invention, and FIG. 1 shows an outline of the left side surface of the motorcycle 1 of this embodiment.
In the motorcycle 1 of the present embodiment, the vehicle body front portion 1A and the vehicle body rear portion 1B are connected via a low floor portion 1C, and the vehicle body frame 2 that forms the skeleton of the vehicle body generally includes a down tube 21 and a main pipe. It consists of 22.
That is, the down tube 21 extends downward from the head pipe 20 of the vehicle body front portion 1A, the down tube 21 is bent horizontally at the lower end, extends rearward below the floor portion 1C, and is connected in the vehicle width direction at the rear end. A pair of left and right main pipes 22 are connected via a frame 23. The main pipe 22 forms an inclined part 22a extending obliquely upward and rearward from the connecting part, and the upper part of the inclined part 22a is further bent and substantially horizontally rearward. A horizontal portion 22b extending in the direction is formed.

A storage box 11 and a fuel tank 12 are supported between the pair of main pipes 22 in the front and rear, and an occupant seat 13 is disposed above the storage box 11 and the fuel tank 12.
On the other hand, in the vehicle body front portion 1A, a handle 14 is provided on the upper side of the head pipe 20 and a front fork 15 extends downward, and a front wheel 16 is supported on the lower end thereof.
A support bracket 24 protrudes rearward from the front end portion of the main pipe 22, and the power unit 3 is connected to and supported by the support bracket 24 via a link member 25 so as to be swingable up and down.

  In the vehicle body front portion 1A, the head pipe 20 and the down directing portion of the down tube 21 are covered from the front and back by the front cover 1a and the leg shield 1b, and in the floor portion 1C, the front and rear directing portion of the down tube 21 is covered by the floor cover 1c. In the rear part 1B of the vehicle body, the main pipe 22 is covered with the body cover 1d on the left and right and the rear.

FIG. 2 is a right side view of the power unit 3 in FIG.
As shown in FIG. 2, the power unit 3 is a water-cooled SOHC type internal combustion engine 4 having a single-cylinder four-stroke cycle at the front, and the cylinder axis X of the cylinder is largely inclined forward to a substantially horizontal state. The end of the hanger arm 32 protruding forward from the lower end of the unit case 30 is connected to the link member 25 via the pivot shaft 26.

In the power unit 3, a belt type continuously variable transmission 5 is configured from the internal combustion engine 4 to the rear, and a rear wheel 17 is provided on a rear axle 51 a that is an output shaft of a reduction gear mechanism 51 provided at a rear portion thereof.
A rear cushion 18 is interposed between the rear portion of the power unit 3 having the speed reduction mechanism 51 and the horizontal portion 22b of the rear portion of the main pipe 22.

The internal combustion engine 4 supports the crankshaft 71 on the unit case 30 so as to be rotatable in the vehicle width direction, that is, the left-right direction, and the cylinder block 41, the cylinder head 42, and the head cover 43 are sequentially stacked in front of the unit case 30. Thus, the cylinder axis X is greatly tilted forward substantially near horizontal and fastened.
2 shows a left unit case 30L serving as a transmission case for housing the belt-type continuously variable transmission 5 in the unit case 30, the belt-type continuously variable transmission 5 itself is housed inside the left unit case 30L. And not shown (see FIG. 3).

In the upper part of the power unit 3, the intake pipe 61 extends from the intake port 65 inlet of the upper part of the cylinder head 42 which is largely inclined forward of the internal combustion engine 4, curves backward, and the throttle body 62 connected to the intake pipe 61 has a cylinder block. An air cleaner 63 (see FIG. 1) located above 41 and connected to the throttle body 62 is disposed above the belt-type continuously variable transmission 5. The intake pipe 61 is provided with an injector 64 that injects fuel toward the intake port 65.
Further, an exhaust pipe (not shown) extending downward from the outlet of the exhaust port 66 at the lower part of the cylinder head 42 is bent rearward, is biased to the right and extends rearward, and is connected to a muffler (not shown) on the right side of the rear wheel 17.

FIG. 3 is a cross-sectional development view of main parts of the power unit 3 as viewed in the direction of arrows III-III in FIG. 2, and mainly shows a portion of the internal combustion engine 4.
In the internal combustion engine 4, a connecting rod (hereinafter simply referred to as a “connecting rod”) 45 connects a piston 44 that reciprocates within a cylinder liner 41 a of a cylinder block 41 and a crank pin 74 of a crankshaft 71.
A combustion chamber 40 is formed in the cylinder head 42 so as to face the top surface of the piston 44.

The unit case 30 is composed of a left and right split left unit case 30L and a right unit case 30R. The right unit case 30R forms the right half of the crankcase portion 35, and the left unit case 30L. The front part forms the left half of the crankcase part 35, and also serves as a transmission case 52 that bulges rearward and accommodates the belt-type continuously variable transmission 5 that is long in the front-rear direction.
The transmission case 52 (left unit case 30L) has an elongated front left and right open surface covered with a transmission case cover 52a, and a transmission chamber 50 in which the belt type continuously variable transmission 5 is housed is formed. The rear right open surface is covered with a reduction gear cover 58 (see FIG. 2), and the reduction gear mechanism 51 is housed inside.

As shown in FIG. 3, the crankcase 71 is formed in the left and right unit cases 30L and 30R in the crankcase portion 35 formed by combining the front portion of the left unit case 30L and the right unit case 30R. The left and right main bearings 36L and 36R are rotatably supported by the left and right side walls 35a of the part 35, and the left and right main bearings 36L and 36R are both constituted by ball bearings.
Of the outer shaft portion of the crankshaft 71 arranged in the vehicle width direction (left-right direction) extending in the left-right horizontal direction, the right outer shaft portion 71R has a cam chain drive sprocket 46 and an oil pump drive gear 47. In addition to being fitted, an AC generator 48 is provided at the right end, and a centrifugal weight 53 and a drive pulley 54 of the belt type continuously variable transmission 5 are provided on the left outer shaft portion 71L.

The internal combustion engine 4 of the present embodiment employs a SOHC type two-valve system, and a valve mechanism 9 including a camshaft 91 and the like is provided in a cylinder head 42.
The cylinder head 42 is covered with a head cover 43 so as to cover the valve mechanism 9.
A cam chain 92 that transmits power to the valve mechanism 9 in the head cover 43 is installed between the camshaft 91 and the crankshaft 71, and the cam chain chamber 49 therefor includes a right unit case 30R, a cylinder block 41, It is provided in communication with the cylinder head 42 (see FIG. 2).

That is, the cam chain 92 is connected to the cam chain chamber 49 between the cam chain driven sprocket 93 fitted to the right end of the cam shaft 91 oriented in the horizontal direction and the cam chain drive sprocket 46 fitted to the crankshaft 71. The camshaft 91 is rotated and driven synchronously at a rotational speed half that of the crankshaft 71.
On the other hand, a spark plug 40 a is fitted into the cylinder head 42 from the opposite side (left side) of the cam chain chamber 49 toward the combustion chamber 40.

The belt type continuously variable transmission 5 on the left side of the power unit 3 is configured such that a V belt 55 is stretched between a driving pulley 54 and a driven pulley (not shown) to transmit power from the crankshaft 71, and the power is transmitted according to the engine speed. The winding weight of the V belt 55 in the drive pulley 54 is changed by the centrifugal weight 53, and at the same time the winding diameter in the driven pulley is changed, so that the gear ratio is automatically changed and continuously variable. Further, the speed is reduced by the reduction gear mechanism 51, the rotational power is transmitted to the rear axle 51a, and the rear wheel 17 is driven (see FIG. 2).
The speed change transmission mechanism itself composed of the belt type continuously variable transmission 5 and the reduction gear mechanism 51 in the present embodiment is well known in the art, and detailed description of the speed change transmission mechanism will be omitted below.

FIG. 4 is an elevational cross-sectional view including the crankshaft 71 of the power unit 3 as viewed in the direction of arrows IV-IV in FIG. 2. As shown in FIG. 4, below the crankshaft 71, there is provided an oil pump 8 that is rotated by an oil pump driven gear 82 that is engaged with and driven by the oil pump drive gear 47 (see FIG. 2).
An oil sump 83 is provided at the bottom of the unit case 30, and the oil that has passed through the oil filter 84 from the oil sump 83 passes through the oil suction path 85 and is connected to the suction port of the oil pump 8.
The oil sucked into the discharge port 86 and discharged from the discharge port 87 passes through an oil supply path (not shown) and is supplied to predetermined lubrication points and cooling points.

In the internal combustion engine 4 of the power unit 3 of the present embodiment as described above, the crankshaft 71 includes a left crankshaft portion 72L and a right crankshaft portion 72R that form a pair in the direction of the crankshaft 71, as shown in FIG. The left and right crank webs 73L and 73R are integrally molded, and a crank pin 74 inserted through the large end 45a of the connecting rod 45 is fitted to both the crank webs 73L and 73R, and the left and right crankshaft portions 72L. , 72R are combined and integrated to form an assembly type structure.
The crank pin 74 has a hollow portion 74a having a right end opened.

  In other words, each of the crank webs 73L and 73R is provided with a balance weight portion 75 integrally therewith, and a pin insertion hole 76 into which the tip of the crank pin 74 is inserted, and the crank pin 74 is connected to the left crankshaft. The crankshaft C of the portion 72L and the right crankshaft portion 72R is in press-fit with both the fitting holes 76, 76 in a state where the crankshaft centers C coincide with each other.

As shown in FIG. 3 and FIG. 5 which is an enlarged view around the center portion of the crankshaft 71, the left crankshaft portion 72L is provided with a left crank journal portion 77L adjacent to the left of the left crank web 73L. The left main bearing 36L attached to the bearing boss portion 37 of the left unit case 30L constituting the crankcase portion 35 is supported.
The right crankshaft portion 72R is provided with a right crank journal portion 77R adjacent to the right of the right crank web 73R and is attached to the bearing boss portion 37 of the right unit case 30R constituting the crankcase portion 35. Supported by 36R.
A left outer shaft portion 71L extends to the left of the left crank journal portion 77L, and a right outer shaft portion 71R extends to the right of the right crank journal portion 77R.

  The bearing boss portion 37 of the right unit case 30R is formed with an oil passage groove 37a in the direction of the crankshaft 71 that opens toward the right crank web 73R on the surface in contact with the right main bearing 36R. An oil supply passage 88 through which oil discharged from the oil pump 8 is guided is connected to the oil passage groove 37a.

On the other hand, a web outer surface 78 of a right crank web (“crank web” in the present invention) 73R connected to the right crank journal portion (“crank journal part” in the present invention) 77R is an annular shape that passes through the right crank journal portion 77R. Side plate 100 is provided.
The left and right main bearings 36L and 36R are ball bearings, but the right main bearing 36R is a seal bearing having a seal member 36Ra on the outer surface.

Therefore, the lubricating oil chamber 110 is formed between the web outer surface 78 and the annular side plate 100 attached to the web outer surface 78. The lubricating oil chamber 110 is formed in the bearing boss portion 37 in the axial direction. Oil from the oil supply passage 88 is supplied through the oil passage groove 37a.
The oil supplied to the lubricating oil chamber 110 is subjected to centrifugal force accompanying rotation during operation, but the side plate 100 exerts an effect of blocking the oil to flow the oil from the lubricating oil chamber 110 into the hollow portion 74a of the crank pin 74. .
The oil is supplied to the crankpin bearing 45b loaded in the large end portion 45a of the connecting rod 45 through an oil supply hole 74c provided so as to communicate with the pin outer peripheral surface 74b from the hollow portion 74a and used for lubrication. .
A needle bearing or a roller bearing is used as the crank pin bearing 45b. The crank pin bearing 45b is lubricated by lubrication from the lubrication hole 74c, thereby constituting the connecting rod large end lubrication structure of the internal combustion engine of the present embodiment.

  The side plate 100 is integrally formed of a synthetic resin material, and has a cross-sectional O shape (so-called O-ring shape) on a cross section (for example, as shown in FIGS. 5 and 6) of the outer peripheral edge along the crankshaft center C. It has a fixed portion 101 and a plate-like oil storage plate-like portion 105 extending from the fixed portion 101 toward the crankshaft center C (see FIG. 6).

In this embodiment, the lubricating oil chamber 110 is defined on the web outer surface 78 of the right crank web 73R by the side plate 100 integrally formed of the above synthetic resin material instead of the conventional metal plate side plate. As a result, assembly is facilitated, man-hours are reduced and assemblability is improved, and weight reduction, cost reduction, sealing performance and oil storage performance are improved.
Further, when the internal combustion engine 4 is operated, it receives reciprocating motion from the piston 44 and vibrates around the crank pin 74 on the crank shaft 71 having the drive pulley 54 and the AC generator 48 attached to the left and right outer shaft portions 71L and 71R. However, the resonance noise of the side plate 100 associated therewith is prevented.
In particular, the synthetic resin material is a nylon resin containing glass fiber (30% in this embodiment), and strength is obtained while suppressing the cost of the side plate 100.

6 (a) is a cross-sectional view of the same orientation of the side plate 100 shown in FIGS. 3 and 5, and FIG. 6 (b) is the periphery of the fixed portion 101 at the outer edge of the side plate 100 in FIG. FIG. 4 is an enlarged cross-sectional view showing a state in which the fixing portion 101 is fitted into the right crank web 73R.
On the outer peripheral surface 78a of the right crank web 73R, there is an annular mounting groove 120 facing the inner circumference of the crankshaft radial direction Cr, and an annular projection 121 facing the inner circumference of the crankshaft radial direction Cr outside the crankshaft 71. The fixed portion 101 is held in an elastic state with respect to the annular assembly groove 120 and is locked by the annular convex portion 121.
The assembly structure of the side plate 100 and the weight reduction are compatible by such an assembly structure of the side plate 100.

Further, as shown in FIG. 6, the side plate 100 has a cross section along the crankshaft center C on the inner peripheral side of the connecting portion 102 from the fixing portion 101 having an O-shaped outer peripheral edge to the oil storage plate-like portion 105. The upper radius R2 is set to be larger than the radius R1 on the cross section along the crankshaft center C of the fixing portion 101 having the O cross section (for example, R2 = 1.5R1).
Therefore, it is possible to make it difficult for strain to be transmitted to the oil reservoir plate-like portion 105 due to the contraction force received by the oil reservoir plate-like portion 105 when the fixing portion 101 having the O-shaped cross section at the outer peripheral edge is assembled. The warp of the shape portion 105 can be prevented, and the oil storage plate shape portion 105 can be formed thinner.

The oil reservoir plate-like portion 105 is displaced in the crankshaft direction (rightward in the embodiment) with respect to the fixed portion 101, and the connecting portion 102 with the fixed portion 101 has a crankshaft radius of the fixed portion 101. The direction Cr is connected to the inner peripheral side.
Therefore, the vibration of the oil storage plate-like portion 105 during the operation of the internal combustion engine 4 can reduce the influence on the surrounding fixed portion 101 fitted into the right crank web 73R, the tightening margin can be reduced, and the tightening margin can be increased. This prevents a decrease in assembly performance.

  Further, in the present embodiment, the side plate 100 is configured such that the fixed portion 101 occupies at least 30% (for example, 37% in the present embodiment) by weight with respect to the weight of the entire side plate 100, Therefore, the rigidity and fitting strength of the fixed portion 101 can be obtained, and both a retaining effect and assemblability can be achieved.

In the present embodiment, as shown in FIG. 6B, the plate-like portion outer surface 105a of the oil reservoir plate-like portion 105 is provided in the outer surface peripheral portion 78a of the right crank web 73R in the direction of the crankshaft 71. It is located within the range of the annular convex portion 121.
As such, the plate-like portion outer side surface 105a of the oil storage plate-like portion 105 is drawn by d from the right end surface 73Ra of the right crank web 73R in the crankshaft direction, so that the side plate 100 from the crankshaft direction right end surface 73Ra is drawn. , And the side plate 100 is protected.

FIG. 7A is a cross-sectional view of a modified example of the side plate 100 shown in the same orientation as that of FIG. 6A. The parts (b1) and (b2) are b1 in the part (a). It is a left view of the modification of the side plate 100 by -b1 arrow view and b2-b2 arrow view.
In each modified example, the oil reservoir plate-like portion 105 includes a plurality of oil reservoir ribs 106 or 107 formed radially with respect to the crankshaft center C.
The oil storage rib 106 shown in the (b1) portion has a linear radial rib shape along the crankshaft radial direction Cr, and the oil storage rib 107 shown in the (b2) portion is a spiral extending in the crankshaft radial direction Cr. It has a radial rib shape.
In the (b1) part and (b2) part illustration, the crankshaft 71 rotates in the clockwise direction T.

During operation of the internal combustion engine 4, mechanical wear powder or the like mixed in the oil in the lubricating oil chamber 110 is brought close to the outer peripheral side of the inter-rib space 108 between the oil storage ribs 106 and 107 by the centrifugal force due to the rotation of the crankshaft 71. It is done.
Using this fact, mechanical wear powder in the oil is stored in the lubricating oil chamber 110 (see FIGS. 3 and 5) formed between the web outer surface 78 of the right crank web 73R and the side plate 100. Therefore, it is possible to reduce the long-term intrusion of mechanical wear powder or the like once collected into the connecting rod 45 side.

FIG. 8 is an explanatory view of a modified example of the side plate assembly structure shown in the same orientation as in FIG. 6B and a reference example different from the present invention.
What is shown in FIG. 8 (a) is a modification belonging to the category of the present embodiment, and there is a step between the annular assembly groove 120 and the annular projection 121 of the outer surface peripheral portion 78a of the right crank web 73R. A portion 122 is provided, and the fixing portion 101 of the side plate 100 is also provided with an engagement step portion 103 that engages with the step portion 122 so as to be assembled.
According to the modification shown in part (a), the side plate 100 can be more firmly assembled.

The part shown in FIG. 8B is a reference example different from the present invention studied in connection with the present invention. The side plate 100 includes an annular protrusion 131 that restrains the direction of the crankshaft 71 and a crankshaft radial direction Cr. An annular projection 132 for restraining is provided, and annular grooves 133 and 134 for engaging with the right crank web 73R are provided.
The part shown in FIG. 8 (c) is also a reference example different from the present invention studied in connection with the present invention, and the outer peripheral end 135 of the side plate 100 is formed in the annular groove 136 of the right crank web 73R engaged therewith. The crankshaft 71 direction and the crankshaft radial direction Cr are constrained.
According to the reference examples shown in the parts (b) and (c), the side plate 100 can be firmly assembled. However, in the ease of assembly and removal, the above-described embodiment of the present invention includes It doesn't reach.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various design changes can be made without departing from the scope of the present invention. Of course, vehicles, internal combustion engines, and the like include those implemented in various modes.
For convenience of explanation, the left and right arrangements of the illustrated embodiment have been described. However, even those having different left and right arrangements are included in the present invention as long as they are within the scope of the invention.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 3 ... Power unit, 4 ... Internal combustion engine, 5 ... Belt type continuously variable transmission, 8 ... Oil pump, 30 ... Unit case, 30L ... Left unit case, 30R ... Right unit case 35 ... Crankcase part, 35a ... Side wall, 36L ... Left main bearing, 36R ... Right main bearing, 36Ra ... Seal member, 37 ... Bearing boss part, 37a ... Oil passage groove, 41 ... Cylinder block, 42 ... Cylinder head, 44 ... Piston, 45 ... Connecting rod (connecting rod), 45a ... Lar end, 45b ... Crank pin bearing, 47 ... Oil pump drive gear, 48 ... AC generator, 54 ... Drive pulley, 71 ... Crank shaft, 71L ... Left Outer shaft portion, 71R ... right outer shaft portion, 72L ... left crankshaft portion, 72R ... right crankshaft portion, 73L ... left crank web, 73R ... right crank web ("crank web" in the present invention), 73Ra ... crankshaft Direction right end surface, 74 ... crank pin, 74a ... hollow portion, 74b ... pin outer peripheral surface, 74c ... oil supply hole, 76 ... pin insertion hole, 77L ... left crank journal portion, 77R ... right crank journal portion ("crank in the present invention" Journal part "), 78 ... Web outer surface, 78a ... Outer surface peripheral part, 82 ... Oil pump driven gear, 88 ... Oil supply passage, 100 ... Side plate, 101 ... Fixed part, 102 ... Connection part, 103 ... Engagement stage 105, oil storage plate-like portion, 105a ... plate-like portion outer surface, 106 ... oil storage rib, 107 ... oil storage rib, 108 ... inter-rib space, 110 ... lubricating oil chamber, 120 ... annular assembly groove, 121 ... annular convex part, 122 ... step part, X ... cylinder axis, C ... crankshaft center, Cr ... crankshaft radial direction

Claims (8)

An internal combustion engine (4) in which a lubricating oil chamber (110) is defined by including an annular side plate (100) inserted through the crank journal (77R) on the outer surface (78) of the web of the crank web (73R). In the connecting rod large end lubrication structure of
The side plate (100) has a fixed portion (101) having an O-shaped cross section along the crank shaft center (C) at the outer peripheral edge, and from the fixed portion (101) toward the crank shaft center (C). A connecting rod large end lubricating structure for an internal combustion engine, which has a plate-like oil storage plate-like portion (105) extending and is integrally formed of a synthetic resin material.   The side plate (100) has a crankshaft center (C) on an inner peripheral surface of a connecting portion (102) from the fixing portion (101) having an O-shaped cross section on the outer peripheral edge to the oil storage plate-like portion (105). The radius (R2) on the cross section along the axis is larger than the radius (R1) on the cross section along the crankshaft (C) of the fixed portion (101) having the O-shaped cross section. A connecting rod large end lubrication structure for an internal combustion engine.   The oil storage plate-like portion (105) is displaced in the direction of the crankshaft (71) with respect to the fixed portion (101), and the connecting portion (102) is a radial direction of the fixed portion (101) in the crankshaft radius ( 3. The connecting rod large end lubrication structure for an internal combustion engine according to claim 2, wherein the lubricating structure is connected to the inner peripheral side of Cr).   In the outer surface peripheral portion (78a) of the crank web (73R), an annular assembly groove (120) facing the inner periphery of the crankshaft radial direction (Cr), and an inner periphery facing the outer periphery of the crankshaft (71). An annular convex part (121) is provided, and the fixed part (101) is held in an elastic state with respect to the annular assembly groove (120) and is locked by the annular convex part (121). The connecting rod large end lubricating structure for an internal combustion engine according to any one of claims 1 to 3.   The plate-like portion outer surface (105a) of the oil reservoir plate-like portion (105) is located within the range of the annular convex portion (121) in the crankshaft (71) direction. A connecting rod large end lubricating structure for an internal combustion engine as described.   The oil storage plate-like portion (105) is provided with a plurality of oil storage ribs (106, 107) formed radially with respect to the crankshaft (C) on the surface facing the crank web (73R). A connecting rod large end lubricating structure for an internal combustion engine according to any one of claims 1 to 5.   The said side plate (100) is comprised so that the said fixing | fixed part (101) may occupy at least 30% by weight ratio with respect to the whole side plate (100). A connecting rod large end lubricating structure for an internal combustion engine according to any one of the preceding claims.   The connecting rod large end lubricating structure for an internal combustion engine according to any one of claims 1 to 7, wherein the synthetic resin material is a nylon resin containing glass fiber.

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