JPH06346715A - Lubrication device for internal combustion engine - Google Patents

Abstract

PURPOSE:To effectively utilize dead space in an engine and form an oil guiding means in a crankshaft to a minimum necessary extent. CONSTITUTION:Regarding an engine lubrication device where oil is forcibly supplied to an engine on the operation of an oil pump, a cutout section 48 formed at the time of machining the crank pin coupling port 46R of an engine crankshaft 41 is surrounded with a crank journal 43R, a crank arm 42R, a bearing 59R fastened to the crankshaft 41 and a means 73 to seal space between the bearing 59R and the crank arm 42R, thereby forming an oil relay chamber 74. On the other hand, the crankshaft 41 and the crank pin 45 are respectively provided internally with oil guiding means 70 and 75, and these means 70 and 75 are communicated with each other via the chamber 74.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine lubricating device, and more particularly to an engine lubricating device for lubricating a crankshaft system.

[0002]

2. Description of the Related Art A crankshaft provided in an engine converts an explosive force due to combustion applied to a piston from reciprocating motion to rotary motion. The reciprocating motion of the piston is transmitted to the crankshaft by a connecting rod (connecting rod).

For example, as shown in FIG. 6, a crankshaft 2 mounted in a four-cycle single-cylinder engine 1 equipped with a V-belt type automatic transmission is a crank journal 3.
And a crank arm 4, a balance weight 5 is provided at one end of the crank arm 4, and a crank pin 6 is provided at the other end of the crank arm 4.

A large end portion 9 of a connecting rod 8 is connected to the crank pin 6 via a metal bearing 7. A piston 12 is connected to the small end 10 of the connecting rod 8 via a piston pin 11.

When the fitting port 13 for fitting the crank pin 6 into the crank arm 4 is formed by, for example, a drill, a notch 14 is formed on the outer surface of the crank journal 3.

On the other hand, a starter clutch 15 is provided on the left side of the crank arm 4 of the crankshaft 2 via a needle bearing 16.

The crankshaft 2 is pivotally supported by ball bearings 17R and 17L which are press-fitted into the crankshaft 2 from the left and right and assembled.

The crank pin 6 and the connecting rod large end portion 9
The sliding contact surface with and is subject to a large load in addition to high-speed rotation, and thus must be constantly lubricated. Therefore, in general, oil passages 18a ... 18e are formed in the crankshaft 2 and the crankpin 6, and the oil supplied from the outside is introduced from the oil passages 18a ... 18e to the sliding contact surface. There is. Similarly, an oil passage 18f is also formed in the sliding contact surface between the crankshaft 2 and the starter clutch 15 to guide the oil.

Oil supplied from the outside is provided on the left side of the left ball bearing 17L with two oil seals 1
18f in the crankshaft 2 and the crankpin 6 via an oil guide passage 20 formed by 9a and 19b.

An oil seal 19c is provided on the right side of the crank arm 4 of the crankshaft 2, and two oil seals 19a and 1a forming the oil guide path 20 are provided.
A space (crank chamber) 21 in which the crank arm 4 of the crankshaft 2 is located together with 9b is kept liquid-tight.

By the way, the right side ball bearing 17
A cam chain drive sprocket 22 that drives a cam shaft that is a valve mechanism is provided on the crankshaft 2 on the right side of R, and is connected to the cam shaft by a cam chain 23.

On the other hand, at the left end of the crankshaft 2,
A drive pulley 25 that constitutes a part of the V-belt type automatic transmission 24 is provided.

[0013]

However, the oil passages 18a, 18 are formed in the crankshaft 2 as in the conventional case.
When b, 18c, and 18f are formed, the number of passages is required to be large, the length of the passages becomes long, and the machining becomes complicated, which is likely to cause a cost increase.

If the oil passage 18f is formed in the sliding contact surface between the crankshaft 2 and the needle bearing 16 to guide the oil, the surface pressure between the crankshaft 2 and the needle bearing 16 increases, which is not preferable.

On the other hand, an oil guide passage 20 is provided on the left side of the left ball bearing 17L with two oil seals 19a, 19a.
When formed by b, the drive pulley 25 projects to the left by the width of the oil guide path 20, and as a result, the overall width of the engine 1 increases, while the drive pulley 25 projects to the left, and the V belt 26 forms the left ball bearing. 17
Moving away from L, vibration is disadvantageous.

Since the load on the left side ball bearing 17L increases due to the drive pulley 25 protruding to the left side, it is necessary to increase the size of the left side ball bearing 17L in order to increase the load capacity of the left side ball bearing 17L. As a result, the engine 1 also becomes large.

Furthermore, the conventional oil seal 19a ...
The layout of 19c is based on which oil seal 19a ...
If the oil 19c is not reliably sealed with oil, the engine structure cannot be established, and there is a risk of inconvenience. For example, two oil seals 1 forming the oil guide passage 20.
In the case of 9a and 19b, it is difficult to increase the diameter of the oil passages 18a formed in the crankshaft 2 or increase the number of the oil passages 18a because the strength of the crankshaft 2 makes it difficult. The diameter becomes small, and the oil seals 19a, 19b will not be sufficient in the crankshaft 2 unless the oil is reliably sealed and sent into the oil passages 18a. Further, when the outside air temperature is low and the oil viscosity is high, the oil pressure in the oil guide path 20 immediately after the engine 1 is started is high, so that it is not possible to prevent the oil from leaking from the oil seals 19a and 19b. , 19b, the leaked oil may adhere to the drive pulley 25, which is not preferable because the V belt 26 slips.

Conventionally, the cam chain drive sprocket 22 and the cam chain 23 have not been sufficiently lubricated, and only the performance of the cam chain 23 is improved to improve the self-lubricating property. 23
Cam chain drive sprocket 2
Since the surface pressure with No. 2 becomes high, it is necessary to consider lubrication of the meshing portion more than ever before.

The notch 14 formed on the outer surface of the crank journal 3 is a dead space and is not effectively utilized.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine lubrication device that effectively utilizes a dead space in the engine.

Another object of the present invention is to provide an engine lubricating device in which the means for guiding oil is formed in the crankshaft to the minimum required.

Another object of the present invention is to provide a lubricating device for an engine capable of lubricating the sliding contact surface between the crankshaft and the needle bearing without increasing the surface pressure. An object of the present invention is to provide an engine lubrication device capable of downsizing the engine.

Still another object of the present invention is to provide an engine lubrication device capable of sufficiently lubricating a cam chain drive sprocket and a cam chain.

[0024]

In order to solve the above-mentioned problems, a lubricating system for an engine according to the present invention has the following features.
As described above, the notch formed at the time of machining the crank pin fitting opening of the crankshaft of the engine is provided with a crank journal, a crank arm, a bearing fixed to the crankshaft, and a space between the bearing and the crank arm. The oil relay chamber is formed by surrounding it with a means for sealing.

In order to solve the above-mentioned problems, according to a second aspect of the present invention, there is provided an engine lubrication system in which oil is pumped into the engine by an oil pump.
Means for guiding oil are respectively formed in the crankshaft and the inside of the crankpin, and the means for guiding these oils are communicated with the oil relay chamber.

Further, in order to solve the above-mentioned problems,
As described in claim 3, the means for guiding the oil formed in the crank pin is provided with means for distributing the oil.

Further, in order to solve the above-mentioned problems, as described in claim 4, a seal device is mounted on the side of the bearing, and the seal device opens a central portion of a circular steel plate. Then, while forming a donut shape, and forming an annular recess along the inner peripheral surface on the inside thereof, the recess forms a space between the bearing and the bearing, and oil is introduced from the outside into this space. is there.

Then, in order to solve the above-mentioned problems,
As set forth in claim 5, in an engine provided with a valve operating mechanism, a cam chain drive sprocket and a cam chain for driving the valve operating mechanism are provided adjacent to the sealing device, and oil leaking from the sealing device is provided. Thus, the cam chain drive sprocket and the cam chain are lubricated.

[0029]

In the present invention having the above-mentioned structure, the notch formed at the time of processing the crank pin fitting opening of the crankshaft of the engine, the crank journal, the crank arm, the bearing fixed to the crankshaft,
Since the oil relay chamber is formed by surrounding the bearing and the crank arm with a means for sealing, a dead space in the engine can be effectively utilized.

Further, in an engine lubrication system in which oil is pumped into the engine by means of an oil pump, means for guiding the oil are respectively formed in the crankshaft and the crankpin, and means for guiding these oils are provided as described above. Since the fluid is communicated with the oil relay chamber, the means for guiding the oil can be formed in the crankshaft to the minimum required.

Further, since the means for distributing the oil is provided in the means for guiding the oil formed in the crank pin, the sliding contact surface between the crankshaft and the needle bearing can be lubricated without increasing the surface pressure.

Further, a sealing device is mounted on the side of the bearing, and the sealing device is formed into a donut shape by opening a central portion of a circular steel plate, and an annular shape is formed inside the donut along the inner peripheral surface. On the other hand, the concave portion forms a space between the concave portion and the bearing, and oil is introduced into the space from the outside, so that the engine can be downsized.

In the engine provided with the valve operating mechanism, the cam chain drive sprocket and the cam chain for driving the valve operating mechanism are provided adjacent to the sealing device, and the cam chain is driven by oil leaking from the sealing device. Since the drive sprocket and the cam chain are lubricated, the cam chain drive sprocket and the cam chain can be sufficiently lubricated.

[0034]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a horizontal sectional view showing an example of a 4-cycle single-cylinder engine unit for a motorcycle equipped with a V-belt type automatic transmission to which the present invention is applied. And
FIG. 2 is an enlarged view of a main part of the engine unit.

In FIGS. 1 and 2, the engine 32 is mounted on the front part of the engine unit 31. The engine 32 mainly includes a crankcase 33 and a cylinder 34.
And a cylinder head 35. Inside the crankcase 33, partition walls 36a, 36b, and 36c form a belt chamber 37, a crank chamber 38, and a cam chain chamber 3
9 and a magneto chamber 40.

A crankshaft 41 is arranged in the crankcase 33 at right angles to the traveling direction of the vehicle. The crankshaft 41 is divided into, for example, left and right parts, and is referred to as a right crankshaft 41R and a left crankshaft 41L for convenience. Each of the crankshafts 41R and 41L includes a crank arm 42R and 42L and a crank journal 43R and 43L.
And L.

The crank arms 42R and 42L have balance weights 44R and 44L formed at one ends thereof,
A fitting port 4 for fitting a crank pin 45 described later to the other end.
6R and 46L are formed.

By the way, as shown in FIGS. 3 (a), 3 (b) and 3 (c), when the fitting port 46R is formed in the right crank arm 42R by the drill 47, the outer surface of the right crank journal 43R is A cutout portion 48 having a circular arc cross section is formed as a dead space in the engine 32.

Each crankshaft 41R, 41
The Ls are connected and integrated by the crank pin 45.
A large end portion 51 of a connecting rod 50 is connected to the crank pin 45 via a metal bearing 49. Also,
The small end portion 52 of the connecting rod 50 has a piston pin 53.
The piston 54 is connected via. This piston 54
Reciprocates in the cylinder 34 of the engine 32, and this reciprocating stroke is transmitted to the crankshaft 41 via the connecting rod 50, causing the crankshaft 41 to rotate.

A starter clutch 55 is provided on the left crank journal 43L via a needle bearing 56. The starter clutch 55 is provided with a driven gear 57, and the driven gear 57 is connected to a drive gear of a starter motor (not shown) via an idle gear 58. The starter clutch 55 has a function of transmitting the power of the starter motor to the crankshaft 41 when the engine 32 is started, and is automatically disengaged after the engine 32 is started.

Ball bearings 59R and 59L are press fitted into the right crank journal 43R on the right side of the right crank arm 42R and the left crank journal 43L on the left side of the starter clutch 55, respectively.
In the ball bearings 59R and 59L, the balls 60 are arranged from the upper and lower sides of the outer race 61 and the inner race 62, respectively.
While being sandwiched by and, the left and right are sandwiched by the retainer 63. The outer race 61 is fixed to the partition walls 36a and 36b in the crankcase 33,
The inner race 62 includes the crank journal 43.
The crankshaft 41 is rotatably supported by pressing and fixing R and 43L.

A sealing device 64 is provided on the right side of the right side ball bearing 59R. 4A and 4B are a plan view of the sealing device 64 and a sectional view taken along line I-I. The sealing device 64 is, for example, a doughnut-shaped product formed by opening a central portion of a circular steel plate.
While a plurality of 5 are provided, an annular recess 66 is formed inside the sealing device 64 along the inner peripheral surface.

As shown in FIG. 2, the recess 66 forms a space 67 between itself and the right side ball bearing 59R. An oil inlet 68 is formed in the recess 66 of the sealing device 64, and one end of an oil pipe 69 is connected to the oil inlet 68. The other end of the oil pipe 69 is connected to an oil pump (not shown).

An oil passage 70, which is a means for guiding oil, is formed in the crank pin 45. The opening 70a of the oil passage 70 is opened so as to face the notch 48 formed in the right crank journal 43R.
Further, the oil passage 70 is bored toward the center of the crank pin 45.

From the vicinity of the tip of the oil passage 70,
The metal bearing 4 on the outer peripheral surface of the crank pin 45
9, oil distribution passages 71a and 71b serving as means for distributing oil toward the portion where the crank pin 45 and the starter clutch 55 are in contact with each other. The left and right crank arms 42R and 42L connected by the crank pin 45 are connected to the crank portion 7
2, the crank portion 72 is housed in the crank chamber 38.

A seal washer 73 as a means for sealing between the right ball bearing 59R and the right crank arm 42R is interposed between the right ball bearing 59R and the right crank arm 42R. The seal washer 73 is, for example, an annular plate material, and the inner diameter and the outer diameter thereof are the same as the right side ball bearing 59R.
The inner race 62 has almost the same diameter.

FIG. 5 is a sectional view taken along line II-II in FIG. As shown in FIGS. 2 and 5, the notch 48 formed in the right crank journal 43R is surrounded by the crank pin 45, the inner race 62 of the right ball bearing 59R, and the seal washer 73. The oil relay chamber 74 is formed.

In the right crank journal 43R which contacts the inner race 62 of the right ball bearing 59R, an oil guide path 75 which is a means for guiding oil is bored. One end of the oil guide path 75 has a recess 66 of the sealing device 64 and the right side ball bearing 59.
An opening is formed in a space 67 formed between R and R. The other end of the oil guide path 75 opens into the oil relay chamber 74.

The right side of the right side ball bearing 59R,
That is, the cam chain drive sprocket 76 is provided on the crankshaft 41 in the cam chain chamber 39. On the other hand, a valve mechanism 77 is provided in the cylinder head 35.
Is provided. A cam sprocket 79 is provided at one end of a cam shaft 78 that constitutes a part of the valve mechanism 77,
The cam sprocket 79 is connected to the cam chain drive sprocket 76 by a cam chain 80. Then, by transmitting the rotation of the crankshaft 41 to the camshaft 78, the valve mechanism 77 is operated.

By the way, as shown in FIG. 1, on the left end side of the crankshaft 41, that is, in the belt chamber 37, the drive pulley 82 of the V-belt type automatic transmission 81 is provided.
Is attached to the driven pulley 84 of the V-belt type automatic transmission 81 via the V-belt 83.
It transmits the rotational force of 2.

The driven pulley 84 is rotatably supported by a driven shaft 85 provided at the rear portion of the engine unit 31, and the rotational force of the engine 32 transmitted to the driven pulley 84 is the centrifugal clutch mechanism 8.
It is transmitted to the driven shaft 85 via 6.

The driven shaft 85 is connected to the rear wheel shaft 88 through a mission mechanism 87 which is a reduction gear mechanism and a power transmission device, and the rotation of the engine 32 is transmitted to the rear wheel 89 through the mission mechanism 87. It has become.

On the other hand, the right end side of the crankshaft 41,
That is, in the magneto chamber 40, an alternator 90 forming a part of the charging device and a cooling fan 91 forming a part of the engine cooling system are provided.

The alternator 90 comprises a tie wheel magnet 90a and a stator 90b.
This alternator 90 generates electric power by rotating a stator 90b connected to the crankshaft 41, and transmits power to each part of the vehicle body.

The cylinder 34 of the engine 32 and the cooling fan 91 are covered with a cowling 92. The engine 32 cools around the cylinder 34 by introducing the outside air into the cowling 92 by rotating the cooling fan 91 connected to the crankshaft 41.

Incidentally, the belt chamber 37 and the crank chamber 38
Oil seals 93a and 93b are provided on the partition wall 36a that partitions the partition wall and the partition wall 36c that partition the cam chain chamber 39 and the magneto chamber 40, respectively. The oil seals 93a and 93b are installed so that the open sides of the U-shapes are directed toward the side where the hydraulic pressure is applied.

Next, the operation of this embodiment will be described.

When the engine 32 is started, the engine 3
The oil pump (not shown) is driven by the rotational force of 2.
Oil is pumped to each part of the engine 32. A part of the oil is guided to the recess 66 formed inside the sealing device 64 via the oil pipe 69.

The recess 66 and the right side ball bearing 59.
A space 67 is formed between R and this space 67.
The above oil is introduced into.

The oil introduced into the space 67 is introduced into the crank pin 45 and the inner side of the right ball bearing 59R from the opening 75a of the oil guide passage 75 which is a means for guiding the oil formed in the right crank journal 43R. It is guided toward an oil relay chamber 74 surrounded by the race 62 and a seal washer 73 which is a means for sealing between the right side ball bearing 59R and the right side crank arm 42R.

According to the present invention, the dead space in the engine 32 can be effectively utilized, and the oil guide path 75 in the right crank journal 43R is not long and is easy to machine as in the conventional case, so that the cost is increased. You can hold it down.

On the other hand, oil is then fed to the crank pin 45.
It is guided toward the center of the crank pin 45 from the opening 70a of the oil passage 70, which is means for guiding the oil formed inside, through the oil passage 70. A part of the oil flows from the vicinity of the tip of the oil passage 70 to the crank pin 45.
It is guided to the metal bearing 49 of the connecting rod large end portion 51 through an oil distribution passage 71a which is a means for distributing oil bored toward the outer peripheral surface. In addition, a part of the oil is an oil distribution passage 71b which is means for distributing the oil bored from the vicinity of the tip of the oil passage 70 toward the joint surface between the crank pin 45 and the starter clutch 55.
After that, it is also guided to the starter clutch 55.

Since the opening of the oil distribution passage 71b guided to the starter clutch 55 is not opened to the contact surface with the needle bearing 56 as in the conventional case, the surface pressure between the needle bearing 56 and the crankshaft 41 increases. There is no such thing.

Further, the opening 70a of the oil passage 70 is
It is not in contact with the inner surface of the fitting port 46R, and the opening 75a of the oil guide path 75 is also the right side ball bearing 59R.
Since it is not in contact with the inner race 62 of the crank pin 45 and the right side ball bearing 59R, there is no galling, so when the oil passage 70 and the oil guide passage 75 are drilled, those openings 70a, 75a are formed.
Since chamfering of the edge is unnecessary, the assembling work becomes easy and the processing cost can be reduced. Further, since no galling occurs at the time of press fitting, the number of defective products is reduced and the cost is reduced.

On the other hand, in the present invention, the right side ball bearing 5
Since the seal device 64 is provided on the right side of 9R and the oil is introduced into the crankshaft 41 from this, it is not necessary to form an oil guide path with an oil seal as in the conventional case, and the drive pulley 82 projects to the left side. There is nothing to do. As a result, the width of the engine 32 becomes smaller. Further, the load on the left side ball bearing 59L is lightened, and there is no need to increase the size of the left side bearing 59L, and the engine 32 can be downsized as a whole. Further, since the V belt 83 approaches the left ball bearing 59L, vibration is also reduced.

By the way, a part of the oil pumped into the sealing device 64 inevitably leaks from the sealing device 64, but in the present invention, the sealing device 64 is arranged adjacent to the cam chain drive sprocket 76. Therefore, the leaked oil can be positively used to sufficiently lubricate the cam chain drive sprocket 76 and the cam chain 80.

In the above embodiment, the present invention is applied to the four-cycle engine for motorcycles.
It can be applied to engines for other purposes, and can also be applied to two-cycle engines.

[0069]

As described above, according to the engine lubrication apparatus of the present invention, the notch portion formed at the time of processing the crank pin fitting port of the crank shaft of the engine, the crank journal, the crank arm, Since the oil relay chamber is formed by surrounding the bearing fixed to the crankshaft and the means for sealing between the bearing and the crank arm, the dead space in the engine can be effectively utilized.

Further, in the engine lubrication system in which the oil is pumped into the engine by the oil pump, means for guiding the oil are formed inside the crankshaft and the inside of the crankpin, and the means for guiding the oil are the above-mentioned means. Since the fluid is communicated with the oil relay chamber, the means for guiding the oil can be formed in the crankshaft to the minimum required.

Further, since the means for distributing the oil is provided in the means for guiding the oil formed in the crank pin, the sliding contact surface between the crankshaft and the needle bearing can be lubricated without increasing the surface pressure.

Further, a sealing device is attached to the side of the bearing, and the sealing device is formed into a donut shape by opening the central portion of a circular steel plate, and an annular shape is formed inside the donut along the inner peripheral surface. On the other hand, the concave portion forms a space between the concave portion and the bearing, and oil is introduced into the space from the outside, so that the engine can be downsized.

In the engine provided with the valve operating mechanism, the cam chain drive sprocket and the cam chain for driving the valve operating mechanism are provided adjacent to the sealing device, and the cam chain is driven by the oil leaking from the sealing device. Since the drive sprocket and the cam chain are lubricated, the cam chain drive sprocket and the cam chain can be sufficiently lubricated.

[Brief description of drawings]

FIG. 1 is a horizontal cross-sectional view of a 4-cycle single-cylinder engine unit for a motorcycle showing an embodiment of an engine lubrication device according to the present invention.

FIG. 2 is an enlarged view of a main part of the engine unit shown in FIG.

3 (a), (b) and (c) are views showing a process of processing a crank pin fitting port.

4A and 4B are a plan view and a cross-sectional view taken along the line II of the sealing device.

5 is a cross-sectional view taken along the line II-II of FIG.

FIG. 6 is a view showing a main part of a conventional engine unit.

[Explanation of Codes] 31 Engine Unit 32 Engine 33 Crankcase 41 Crankshaft 42R, 42L Crank Arm 43R, 34L Crank Journal 45 Crank Pins 46R, 46L (Crank Pin) Fitting Port 48 Cutout 50 Connecting Rod 51 Connecting Rod Large End 55 Starter Clutch 56 Needle Bearing 59R, 59L Ball Bearing 61 Outer Race 62 Inner Race 64 Sealing Device 66 Recess 67 (Formed Inside Sealing Device) Space 67 (Forming Between Recess and Right Ball Bearing) 70 Oil Passages (means for guiding oil) 71a, 71b Oil distribution passages (means for distributing oil) 73 Seal washers (means for sealing between bearing and crank arm) 74 Oil relay chamber 5 Oil guideway (means for guiding the oil) 76 cam chain drive sprocket 80 cam chain

Claims (5)

[Claims] 1. A notch formed at the time of processing a crank pin fitting opening of a crankshaft of an engine, a notch formed between a crank journal, a crank arm, a bearing fixed to the crankshaft, and the bearing and the crank arm. An engine lubrication device characterized in that an oil relay chamber is formed by being surrounded by means for sealing. 2. A lubricating device for an engine in which oil is pumped into the engine by means of an oil pump, wherein means for guiding the oil are respectively formed inside the crankshaft and the crankpin, and means for guiding these oils are provided as above. The engine lubrication device according to claim 1, wherein the oil relay chamber communicates with the oil relay chamber. 3. The engine lubricating system according to claim 1, wherein the means for guiding the oil formed in the crank pin is provided with means for distributing the oil. 4. A seal device is mounted on the side of the bearing, and the seal device is formed into a donut shape by opening a central portion of a circular steel plate and has an annular shape along the inner peripheral surface inside thereof. The engine lubrication device according to claim 1, 2 or 3, wherein, while forming a recess, the recess forms a space with the bearing, and oil is introduced into the space from the outside. 5. In an engine having a valve mechanism, a cam chain drive sprocket and a cam chain for driving the valve mechanism are provided adjacent to the seal device, and the cam chain is caused by oil leaking from the seal device. The engine lubrication device according to claim 1, 2, 3 or 4, wherein the drive sprocket and the cam chain are lubricated.