JP2000161333A - Connecting rod supporting structure of v-type internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce frictional resistance between both rolling bearings and to smooth each rolling action by interposing a center thrust washer between opposed end faces of large end parts of first and second connecting rods and between opposed end faces of the first and second rolling bearings. SOLUTION: First and second connecting rods 81, 82 relatively repeat oscillation according to revolution of a crank pin 5a. Between opposed end faces of retainers 12, 12 of first and second needle bearing 101, 102 and between opposed end faces of large end parts of the first and second connecting rods 81, 82, a common center thrust washer 14 is interposed. Therefore, direct rubbing of the end faces each other is avoided and friction of each end face is reduced by half. As a result, frictional resistance between the retainers 12, 12 is reduced and a rolling action of each needle 11 can be smoothed in both of the needle bearing 101, 102, and relative rotation can be smoothed in the large end parts of both the first and second connecting rods 81, 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a first and second connecting rods of a first and a second bank arranged in a V-shape.
The present invention relates to a connecting rod support structure of a V-type internal combustion engine, which is supported via rolling bearings.

[0002]

2. Description of the Related Art In a conventional V-type internal combustion engine, a plain bearing is used to support a large end portion of a first and a second connecting rod by a common crank pin (for example, see Japanese Unexamined Patent Publication No.
4-83912).

[0003]

When plain bearings are used to support the large end portions of the first and second connecting rods by a common crank pin as in the prior art, the plain bearings generate sliding friction and are relatively small. When a large amount of lubricating oil is required, when the internal combustion engine is operated at a low speed, the amount of oil discharged from the oil pump is reduced. For this reason, a large-capacity oil pump is generally employed to lubricate the bearings without excess or shortage even when the internal combustion engine is operating at a low speed. The amount becomes excessive and power loss due to this is spared.

[0004] Therefore, as a bearing capable of obtaining a good lubrication state even with a relatively small amount of oil, there is a rolling bearing such as a needle bearing, which is used for supporting the large ends of the first and second connecting rods by a common crank pin. If it is used, there is no need to particularly increase the capacity of the oil pump, which is advantageous. However, in this case, during the operation of the internal combustion engine, the end faces of the adjacent rolling bearings greatly rub against each other due to the relative swing of the first and second connecting rods.
It is conceivable that the frictional resistance at that time hinders the rolling action of each rolling bearing to some extent.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and when a rolling bearing is used to support the large end portions of the first and second connecting rods by a common crankpin, the end faces of adjacent rolling bearings are connected to each other. Of the rolling bearing of the V-type internal combustion engine, which can avoid the friction of each other and smooth the rolling action of each rolling bearing, thereby enabling the first and second connecting rods to smoothly swing relative to each other and suppressing the power loss. The purpose is to provide a structure.

[0006]

In order to achieve the above object, the present invention relates to a method in which large ends of first and second connecting rods of first and second banks arranged in a V-shape are connected to a crankshaft. A connecting rod support structure for a V-type internal combustion engine supported on a common crank pin via first and second rolling bearings, respectively, between opposed end faces of large ends of the first and second connecting rods, and A first feature is that a central thrust washer is interposed between opposed end faces of the first and second rolling bearings.

According to the first feature, it is possible to avoid direct rubbing between the end faces and reduce the friction between the end faces by half. As a result, the frictional resistance between the two rolling bearings is reduced, and the rolling action can be made smooth.
The relative rotation can be made smooth.

The present invention, in addition to the above features, further comprises a plurality of needles, wherein the first and second rolling bearings are annularly arranged between a crankpin and a large end of each connecting rod.
A second feature is a needle bearing comprising a retainer having a large number of holding holes for holding the needles, wherein the central thrust washer is interposed between opposed end faces of the retainers of both needle bearings.

According to the second feature, a needle bearing is used to support the large end of each connecting rod, thereby supporting the high output of the internal combustion engine without increasing the diameter of the large end of each connecting rod. be able to. In addition, the friction between the retainers of both needle bearings can be reduced by half by the central thrust washer, so that the rolling action of each needle can be made smooth.

Further, in addition to the second feature, the present invention further includes a side thrust washer between a large end of each connecting rod, a retainer of each needle bearing, and a facing end face of a crank arm of a crankshaft. This is the third feature of being dressed.

According to the third feature, it is possible to avoid the direct rubbing between the end faces, to reduce the friction between the end faces by half, and to smoothly perform the relative rotation between the connecting rod and the crank arm. can do.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIG. 1 is a cross-sectional view of a V-type internal combustion engine for a motorcycle having a connecting rod support structure according to the present invention, and FIG. 2 is a cross-sectional view taken along line 2-2 of FIG.

First, in FIG. 1, a V-type internal combustion engine E is
On top of the crankcase 1, the first and second bank 2 ₁ are arranged in a V-shape along the front-rear direction of the motorcycle, 2 ₂
And the opening angle of these banks 2 ₁ and 2 ₂ is
The angle is set at 90 ° about the crankshaft 3 supported on the crankcase 1.

As shown in FIGS. 1 and 2, the crankshaft 3
Includes a pair of left and right crank journal 4 _1, 4 _2, consists of a single crank portion 5 for connecting the crank journals 4 _1, 4 ₂ ball bearings 13 ₁ on the left and right side walls of the crankcase 1, 13 Supported through ₂ ,
A crank pin 5a of a single crank portion 5, the first and second piston 7 _1, 7 ₂ to the piston 7 that is the first and second bank 2 _1, 2 ₂ of the cylinder bore 6 _1, 6 ₂ fitted to ₁ ,
7 ₂ is connected via first and second connecting rods 8 ₁ , 8 ₂ .

That is, the first and second connecting rods 8 ₁ , 8 ₂
The small end is connected to a piston pin 9 _1, 9 ₂ via the first and second piston 7 _1, 7 _2, their large end,
The common crank pin 5a is supported via first and second needle bearings 10 ₁ and 10 ₂ as first and second rolling bearings.

The needle bearings 10 ₁ and 10 ₂ are:
Numerous needle is arranged annularly between each of the first and second connecting rod _81, 82 of the large end portion and the crank pin 5a 1
1, a plurality of retaining holes 12a for holding the needle 11 rotatably, an annular retainer 12 which is disposed between the large end and the crank pin 5a of each connecting rod _81, 82 And the axial width of the retainer 12 is set equal to the axial width of the large end of each of the connecting rods 8 ₁ , 8 ₂ .

The first and second needle bearings 10 ₁ ,
And while the end faces facing each of the 10 _second retainer 12, 12, between the end faces facing each other of the first and second connecting rod _81, 82 of the big end, common central thrust washer 14 is Kai裝. In addition, the retainer 12 of the first needle bearing 8 ₁
And is between the end faces facing each between one of the crank arms 5b ₁ of the first connecting rod 8 ₁ of the large end portion and the crank portion 5, a common side thrust washer 15 ₁ is Kai裝further second needle bearing 8 between the end faces facing each of the _second retainer 12 and the second large end of the connecting rod ₈₂ and the other crank arm 5b ₂ of the crank portion 5, a common side thrust washer 15 ₂ is Kai裝.

In the crankshaft 3, one of the crankshafts
Journal 4_TwoOil from an oil pump (not shown)
Is formed. Also crank
The pin 5a has a hollow portion 22 whose ends are closed by caps 21.
And a through hole 23 communicating the hollow portion 22 with the oil passage 20.
And the hollow portion 22 is connected to the first and second needle bearings 10.
₁, 10_TwoCommunicating with the outer peripheral surface of the crank pin 5a corresponding to
Refueling hole 24₁, 24 _TwoAre provided.

[0020] On both end faces of the first and second connecting rod _81, the large end of the 8 _2, radial plural rows of oil grooves 25 are engraved.

Next, the operation of this embodiment will be described.

During operation of the internal combustion engine E, an oil pump (not shown)
Pump to crank journal 4_TwoSupplied to the oil passage 20
The oil transferred to the hollow portion 22 of the crank pin 5a
ゝ to the first and second oil supply holes 24₁, 24_TwoFirst by
And second needle bearing 10₁, 10_TwoDistributed to
These parts are lubricated and thrust washers 14,
Fifteen₁, 15_TwoLubricate the surroundings. Needle Bear above
Ring 10₁, 10_TwoThe rolling resistance of the needle 11 is
Because it is much smaller than the plain bearing's sliding resistance,
Each needle bearing 10 with a relatively small amount of oil₁,
10_TwoCan be lubricated well, and
At low speed operation of the internal combustion engine when the discharge oil amount of the
Also does not cause insufficient lubrication. Moreover, the needle bare
Ning 10 ₁, 10_TwoIs relatively compact
And the load capacity is large.₁, 8_Two
High output of the internal combustion engine E without increasing the diameter of the large end of the engine
Can withstand.

The first and second needle bearings 10 ₁ ,
The lubricated oil such as 10 ₂ scatters around with the rotation of the crankshaft 3 and the first and second pistons 7 ₁ , 7
Lubricate ₂ mag.

The first and second connecting rods 8₁,
8_TwoMoves relatively with the revolution of the crank pin 5a.
Again, the first and second needle bearings 10₁,
10 _TwoBetween the opposite end faces of the retainers 12 and 12
1st and 2nd connecting rod 8₁, 8_TwoOpposite of the large end of
A common central thrust washer 14 is interposed between the end faces.
So that direct rubbing between the end faces is avoided.
At the same time, the friction of each end face is reduced by half. So
As a result, both needle bearings 10₁, 10_TwoAt
Reduces the frictional resistance between the retainers 12
The rolling action of the dollar 11 can be smoothed,
First and second connecting rods 8₁, 8_TwoAt the big end of
Can make the relative rotation smooth. Thus, both
Connecting rod 8₁, 8_TwoEnables smooth relative swing
As a result, friction loss of power can be reduced.

Each of the needle bearings 10 ₁ , 10 ₂
The retainer 12, 12 and connecting rods _81, 82 and ₂ of the large end portion, the crank arm 5b ₁ adjacent thereto, 5b
Between the end faces facing each of the _2, since the common side thrust washer 15 _1, 15 ₂ is Kai裝, with rubbing directly above the end faces each other is avoided, friction of the respective end faces As a result, the relative rotation between the connecting rods 8 ₁ , 8 ₂ and the crank arms 5b ₁ , 5b ₂ can be made smooth, and the friction loss of power can be further reduced.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the gist of the present invention.

[0027]

As described above, according to the first feature of the present invention, the large ends of the first and second connecting rods of the first and second banks arranged in a V-shape are connected to the common shaft of the crankshaft. A connecting rod support structure for a V-type internal combustion engine, wherein the crankpin is supported via first and second rolling bearings, respectively.
Between opposing end faces of the large ends of the first and second connecting rods,
In addition, since the central thrust washer is interposed between the opposing end faces of the first and second rolling bearings, it is possible to avoid direct rubbing between the end faces and reduce the friction between the end faces by half. As a result, the frictional resistance between the two rolling bearings is reduced, and the rolling action can be made smoother, and at the large ends of the two connecting rods, the relative rotation can be made smoother. Both connecting rods can smoothly swing relative to each other, which can contribute to a reduction in friction loss of power.

According to a second feature of the present invention, the first and second rolling bearings include a plurality of needles arranged annularly between a crankpin and a large end of each connecting rod;
The needle bearing comprises a retainer having a large number of holding holes for holding the needles. Since the central thrust washer is interposed between the opposed end faces of the retainers of both needle bearings, the large end of each connecting rod is large. It is possible to cope with the high output of the internal combustion engine without increasing the diameter, and the friction between the retainers of both needle bearings is reduced by half by the central thrust washer, so that the rolling action of each needle can be made smooth.

According to a third feature of the present invention, a side thrust washer is interposed between a large end of each connecting rod, a retainer of each needle bearing, and an opposite end face of a crank arm of a crankshaft. As a result, it is possible to avoid direct rubbing between the end faces, reduce the friction between the end faces by half, smooth the relative rotation between the connecting rods and the crank arm, and reduce the friction loss of power. It can contribute to further reduction.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a V-type internal combustion engine for a motorcycle having a connecting rod support structure of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

[Explanation of symbols]

E Internal combustion engine 2 ₁ First bank 2 ₂ Second bank 3 Crankshaft 5a Crank pin 5b ₁ Crank arm 5b ₂ Crank arm 8 ₁ ... 1st connecting rod 8 ₂ ... 2nd connecting rod 10 ₁ ... 1st rolling bearing (1st needle bearing) 10 ₂ ... 2nd rolling bearing (2nd needle bearing) 11 ... needle 12 ...・ Retainer 12a ・ ・ Holding hole 14 ・ ・ ・ Central thrust washer 15 ₁・ ・ Side thrust washer 15 ₂・ ・ Side thrust washer

Claims (3)

[Claims] 1. A first and second connecting rods (8 ₁ , 2 1) of first and second banks (2 ₁ , 2 ₂ ) arranged in a V-shape.
8 ₂ ), the first and second rolling bearings (10 ₁ , 10 2) are attached to the common crank pin (5 a) of the crank shaft (3).
₂ ) a connecting rod support structure for a V-type internal combustion engine, each of which is supported through a first connecting rod and a second connecting rod (8).
_A central thrust washer (14) is interposed between the opposed end faces of the large end of ( ₁ , 8 ₂ ) and between the opposed end faces of the first and second rolling bearings (10 ₁ , 10 ₂ ). A connecting rod support structure for a V-type internal combustion engine. 2. A connecting rod support structure for a V-type internal combustion engine according to claim 1, wherein said first and second rolling bearings (1) are provided.
0 ₁ , 10 ₂ ) is composed of a number of needles (11) arranged annularly between the crank pin (5 a) and the large end of each connecting rod (8 ₁ , 8 ₂ ). Retainer (1) having a number of holding holes (12a) for holding
2) wherein the central thrust washer (14) is interposed between opposed end faces of a retainer (12) of both needle bearings (10 ₁ , 10 ₂ ). Connecting rod support structure for internal combustion engines. 3. The connecting rod support structure for a V-type internal combustion engine according to claim 2, wherein each of said connecting rods (8 ₁ , 8 ₂ ).
Large end and needle bearings (10 ₁ , 10 ₂ )
And the retainer (12), wherein it has Kai裝crank arm (5b _1, 5b ₂₎ opposing the end face side thrust washer between the (15 _1, 15 ₂₎ of the crank shaft (3), Connecting rod support structure for V-type internal combustion engine.