JP3139222B2 - Lubrication system for motorcycle 4-cycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine lubrication apparatus, and more particularly to an engine lubrication apparatus 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 a reciprocating motion to a rotating motion. The reciprocating motion of the piston is transmitted to the crankshaft by a connecting rod (connecting rod).

For example, as shown in FIG. 8, a crankshaft 2 mounted in a four-cycle single-cylinder engine 1 equipped with a V-belt type automatic transmission includes a crank arm 3,
A balance weight 5 is provided at one end of the crank arm 3, and a crank pin 6 is provided at the other end of the crank arm 3.

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

On the other hand, on the left side of the crank arm 3 of the crankshaft 2 in FIG.
3 is provided via a needle bearing 14.

The crankshaft 2 is supported by ball bearings 15R and 15L which are press-fitted into the crankshaft 2 from right and left. The right ball bearing 15R is positioned by a flange 17 formed integrally with the partition 16 of the crankcase.

The crank pin 6 and the connecting rod large end 9
Since the sliding contact surface rotates at a high speed and a large load is applied, it is necessary to constantly lubricate the surface. Therefore, generally, oil passages 18a to 18e are formed in the crankshaft 2 and the crankpin 6, and oil supplied from outside is guided from the oil passages 18a to 18e to the sliding surface. I have. Similarly, an oil passage 18f is formed on the sliding contact surface between the crankshaft 2 and the starter clutch 13 to guide oil.

The oil supplied from the outside is provided on the left side of the left ball bearing 15L by two oil seals 1
Oil passages 18a... 18f in the crankshaft 2 via an oil guide passage 20 formed by 9a, 19b.
Is led to.

An oil seal 19c is provided on the right side of the crank arm 3 of the crankshaft 2, and two oil seals 19a and 19a forming the oil guide path 20 are provided.
A space (crank chamber) 21 where the crank arm 3 of the crankshaft 2 is located is kept liquid-tight together with 19b.

The right ball bearing 15
A cam chain drive sprocket 22 as a cam chain mechanism for driving a cam shaft as a valve mechanism is provided on the crankshaft 2 on the right side of R.
The cam chain 23 is connected to the camshaft.

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

[0012]

However, when the oil passages 18a are formed in the crankshaft 2 as in the prior art, the machining is complicated, for example, a large number of passages are required or the length of the passages is increased. It is easy to become a factor of cost increase.

Further, if the edge of the oil passage 18a comes into contact with the inner race 26 of the left ball bearing 15L when the crankshaft 2 is assembled, there is a possibility that galling occurs, so that the edge of the oil passage 18a is chamfered. Must be performed, which is troublesome.

Further, if an oil passage 18f is formed in the sliding surface between the crankshaft 2 and the needle bearing 14 to guide the oil, the surface pressure between the crankshaft 2 and the needle bearing 14 increases, which is not preferable.

Since the crankcase is usually formed by casting such as die casting, when the flange 17 for positioning the right ball bearing 15R is formed integrally with the partition 16 of the crankcase, the flange 17 is formed by a mold. It complicates processes such as production and die cutting, leading to increased costs.

On the other hand, an oil guide path 20 is provided on the left side of the left ball bearing 15L by two oil seals 19a, 19a.
b, the drive pulley 25 projects to the left by the width of the oil guide path 20. As a result, the overall width of the engine 1 increases, while the V-belt 27 projects by the drive pulley 25 to the left. Fifteen
Away from L and vibration is disadvantageous.

Further, since the load on the left ball bearing 15L is increased by the amount that the drive pulley 25 projects to the left, it is necessary to increase the size of the left ball bearing 15L in order to increase the load capacity of the left ball bearing 15L. As a result, the size of the engine 1 also increases.

Further, the conventional oil seals 19a.
The layout of the oil seal 19c is as follows.
In 19c, too, unless the oil is securely sealed, the engine structure cannot be established, which may cause inconvenience. For example, two oil seals 1 forming the oil guide path 20
9a and 19b, the diameter of the oil passages 18a formed in the crankshaft 2 is increased,
Since it is difficult to increase the number of the oil passages 8a, because of the strength of the crankshaft 2, the diameter of the oil passages 18a becomes small, and the oil seals 19a, 19b must securely seal the oil and feed the oil into the oil passages 18a. For example, the amount of oil in the crankshaft 2 becomes insufficient.

When the temperature of the outside air is low and the viscosity of the oil is high, the oil pressure in the oil guide path 20 immediately after the start of the engine 1 increases, so that the oil cannot be prevented from leaking from the oil seals 19a and 19b. Oil seal 19
In the arrangements a and 19b, the leaked oil is
The V-belt 27 may be undesirably adhered to the V-belt 5.

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 has been improved to improve the self-lubricating property. 23
Cam chain drive sprocket 2
Therefore, the lubrication of the meshing portion needs to be considered more than before.

The present invention has been made in view of the above circumstances, and has as its object to provide an engine lubricating apparatus in which a means for guiding oil having a short length and easy to work is formed in a crankshaft. One purpose.

A second object of the present invention is to provide a lubricating device for an engine which prevents galling on bearings when assembling a crankshaft.

A third object of the present invention is to provide a lubricating device for an engine capable of lubricating a sliding surface between a crankshaft and a needle bearing without increasing a surface pressure.

[0024] A fourth object of the present invention is to provide an engine lubricating device which can reduce the size of the engine.

A fifth object of the present invention is to provide a lubricating device for an engine in which a bearing can be easily positioned.

A sixth object of the present invention is to provide a lubricating device for an engine capable of sufficiently lubricating a cam chain mechanism.

[0027]

According to a first aspect of the present invention, there is provided a lubricating apparatus for a four-stroke engine for a motorcycle, wherein one end of the lubricating apparatus faces a V-belt chamber. On the other hand, a crankshaft in which an alternator is provided at the other end is supported by ball bearings on both sides of the crank arm, and the inside of the crankshaft is located near a ball bearing that supports the crankshaft on the side where the alternator is provided. A four-cycle motorcycle for motorcycles provided with an inlet of an oil passage through which oil is supplied to the crank pin through a passage, and a V-belt automatic transmission for lubricating the crank pin by supplying oil from an oil pump to the passage. In the engine lubrication apparatus, the V
A cam chain drive sprocket is provided on the crankshaft on the side opposite to the belt chamber, and an introduction port of the oil passage is opened near the cam chain drive sprocket, and the ball bearing and the cam chain are provided. An oil sump is formed between the drive pinion and the drive sprocket, and oil for lubricating the crankpin is pumped by an oil pump via the oil sump, and is driven by a cam chain drive sprocket with oil leaking from the oil sump. The lubricating cam chain is configured to be lubricated.

[0028]

[0029]

[0030]

[0031]

[0032]

[0033]

According to the present invention having the above structure, in a lubrication system for an engine in which oil is pumped into an engine by an oil pump, a bearing is press-fitted into a crank journal of a crankshaft and comes into contact with the bearing of the crank journal. Since the means for guiding the oil from the surface to the crank pin is provided in the crank journal, the means for guiding the oil, which is short in length and easy to process, can be formed in the crankshaft.

In addition, since the oil guiding means has the opening edge facing the bearing separated from the outer surface of the bearing, it is possible to prevent galling on the bearing when assembling the crankshaft. .

[0035]

[0036]

[0037]

Further, a cam chain mechanism for driving a valve operating mechanism is provided on the crankshaft adjacent to the seal device, and the cam chain mechanism is lubricated by oil leaking from the seal device. Can be lubricated.

[0039]

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 four-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.

1 and 2, an engine 31 is mounted at the front of the engine unit 30. The engine 31 mainly includes a crankcase 32 and a cylinder 33
And a cylinder head 34. Inside the crankcase 32, a belt chamber 36, a crank chamber 37, and a cam chain chamber 3 are formed by partition walls 35a, 35b, and 35c.
8 and a magneto chamber 39.

An oil supply passage 40 is formed in the partition 35b. The upper end of the oil supply passage 40 communicates with a stud bolt hole (not shown) in the cylinder 33. The stud bolt hole guides oil supplied into the cylinder head 34 from an oil pump (not shown). An opening 40 a is formed at the lower end of the oil supply passage 40 so as to face the cam chain chamber 38.

A crankshaft 41 is disposed in the crankcase 32 at right angles to the traveling direction of the vehicle. The crankshaft 41 is, for example, divided into left and right, and is referred to as a right crankshaft 41R and a left crankshaft 41L for convenience. Each of the crankshafts 41R, 41L includes a crank arm 42R, 42L and a crank journal 43R, 42R.
L.

The crank arms 42R, 42L have balance weights 44R, 44L formed at one end thereof.
At the other end, a fitting hole 4 into which a crank pin 45 described later is fitted.
6R and 46L are formed.

Each of the crankshafts 41R, 41
L is connected and integrated by a crank pin 45.
A large end 49 of a connecting rod 48 is connected to the crank pin 45 via a metal bearing 47. Also,
The small end 50 of the connecting rod 48 has a piston pin 51
The piston 52 is connected via the. This piston 52
Reciprocates in the cylinder 33 of the engine 31, and this reciprocating stroke is transmitted to the crankshaft 41 via the connecting rod 48 to rotate.

A starter clutch 53 is provided on the left crank journal 43L via a needle bearing 54. The starter clutch 53 is provided with a driven gear 55, and the driven gear 55 is connected to a drive gear of a starter motor (not shown) via an idle gear 56. The starter clutch 53 has a function of transmitting the power of the starter motor to the crankshaft 41 when the engine 31 is started.
After starting, it is automatically cut off.

In FIG. 2, the right crank journal 43R on the right side of the right crank arm 42R and the left crank journal 4 on the left side of the starter clutch 53 are shown.
Ball bearings 57R and 57L are press-fitted into 3L, respectively. These ball bearings 57R, 57L
Is that the ball 58 has an outer race 59
And the inner race 60, while the left and right sides of the ball 58 are held by the retainer 61.

The outer race 59 is fixed to the partition walls 35a, 35b of the crankcase 32, while the inner race 60 is fixed to the crank journals 43R, 43R.
L is press-fitted and fixed, thereby supporting the crankshaft 41 rotatably.

FIG. 3 is a sectional view taken along the line II of FIG. 2, and FIG. 4 is a sectional view taken along the line II-II of FIG.

In FIG. 2, FIG. 3 and FIG. 4, an oil passage 62 as a means for guiding oil is formed in the center of the right crank journal 43R of the crankshaft 41 in contact with the inner race 60 of the right ball bearing 57R. The opening is closed by the cap 62a.
In the center of the left crank journal 43L,
In order to balance the weight, a balance hole 63 equivalent to the oil passage 62 is formed. The right crank journal 4 corresponding to the outer surface of the inner race 60 of the right ball bearing 57R from the right end side of the oil passage 62
A plurality of, for example, three, oil introduction paths 64, which are means for guiding other oil toward the 3R surface, are formed at equal intervals. As shown in detail in FIG. 5, the edge of the right ball bearing 57R side opening 64a of the oil introduction path 64 is provided away from the outer surface of the inner race 60 of the right ball bearing 57R. A space 65 is formed with the outer surface.

Further, an oil guide path 66 is provided as a means for guiding other oil from near the center of the oil passage 62 to the outer peripheral surface of the right crank journal 43R corresponding to the outer peripheral surface of the crank pin 45. . On the other hand, an oil inlet 67 which is a means for guiding oil is formed in a portion of the outer peripheral surface of the crank pin 45 corresponding to the opening 66a of the oil guide path 66, and from the oil inlet 67 to the center of the crank pin 45. An oil guide passage 68, which is a means for guiding another oil toward the oil passage, is formed.

An oil distribution path 69a, which is means for distributing oil from near the tip of the oil guide path 68 to the outer peripheral surface of the crank pin 45, is formed. The oil distribution path 69b, which is means for distributing other oil from near the tip of the oil guide path 68, is connected to the crank pin 45.
And the starter clutch 53.

The right side of the right ball bearing 57R,
That is, a cam chain drive sprocket 70 as a cam chain mechanism is provided on the crankshaft 41 in the cam chain chamber 38. On the other hand, a valve operating mechanism 71 is provided in the cylinder head 34. A cam sprocket 73 is provided at one end of a camshaft 72 constituting a part of the valve train 71, and the cam sprocket 73 and the cam chain drive sprocket 70 are connected by a cam chain 74 as a cam chain mechanism.
The rotation of the crankshaft 41 is controlled by the cam chain 7.
4 to the camshaft 72 via
The valve operating mechanism 71 is operated.

A sealing device 75 is provided on the right side of the right ball bearing 57R. FIG. 6A is a plan view of the sealing device 75, and FIG. 6B is a plan view of FIG.
FIG. 3 is a sectional view taken along line III-III of FIG. FIG. 7 is an arrow view along the line IV-IV in FIG.

This sealing device 75 is similar to that shown in FIG.
As shown in FIG. 7B and FIG. 7, an oil plate 76 and an oil seal 77 are provided. Oil plate 7
Reference numeral 6 denotes, for example, a steel plate that is press-formed into a shape that covers the right ball bearing 57R. A plurality of mounting flanges 78 are provided on the outer peripheral surface of the oil plate 76, while Are formed with convex portions 79a and 79b, which are means for introducing oil.

As shown in detail in FIG. 5, the insides of these convex portions 79a and 79b are connected to the right ball bearing 57.
While the spaces 80a and 80b are formed between the cam chain 74 and the cam chain 74, the spaces 80a and 80b are formed and arranged so as not to contact the cam chain 74 as shown in FIG. The projection 79a is disposed so as to cover the opening 40a of the oil supply path 40.

A shaft hole 81 is formed near the center of the oil plate 76. An oil seal 77 is fitted on the inner peripheral surface of the shaft hole 81, and a lip portion 77 a of the oil seal 77 abuts on an edge portion 43 a of the right crank journal 43 R of the crankshaft 41, and the oil introduction passage 64 Right ball bearing 57
A space 65 formed between the R-side opening 64a and the outer surface of the inner race 60 of the right ball bearing 57R;
A space 8 formed between the convex portions 79a, 79b formed on the oil plate 76 and the right ball bearing 57R.
0a and 80b are kept liquid-tight.

In the sealing device 75, the flange 78 is fixed to the partition wall 35b by fixing means such as a screw 82.

As shown in FIG. 1, the drive pulley 84 of the V-belt type automatic transmission 83 is provided on the left end side of the crankshaft 41, that is, in the belt chamber 36.
Is mounted on a driven pulley 86 of a V-belt type automatic transmission 83 via a V-belt 85.
1 is transmitted.

The driven pulley 86 is rotatably supported by a driven shaft provided at the rear of the engine unit 30. The rotational force of the engine 31 transmitted to the driven pulley 86 is transmitted via a centrifugal clutch mechanism 88. And transmitted to the driven shaft 87.

The driven shaft 87 is connected to a rear wheel shaft 90 via a transmission mechanism 89 which is a reduction gear mechanism and a power transmission device, and the rotation of the engine 31 is transmitted to the rear wheel 91 via the transmission mechanism 89. It has become.

On the other hand, an alternator 92 forming part of a charging device and a cooling fan 93 forming part of an engine cooling system are provided on the right end side of the crankshaft 41, that is, in the magneto chamber 39.

The alternator 92 includes a flywheel magneto 92a and a stator 92b.
The alternator 92 generates electric power by rotating a stator 92b connected to the crankshaft 41, and transmits electric power to various parts of the vehicle body.

The cylinder 33 and the cooling fan 93 of the engine 31 are covered by a cowling 94. The engine 31 rotates the cooling fan 93 connected to the crankshaft 41 to introduce outside air into the cowling 94 to cool around the cylinder 33.

The belt chamber 36 and the crank chamber 37
Oil seals 95a and 95b are respectively provided on the partition wall 35a that separates the cam chain chamber 38 and the magneto chamber 39 from each other. These oil seals 95a and 95b are installed such that the open side of the U-shape faces toward the side where hydraulic pressure is applied.

Next, the operation of this embodiment will be described.

When the engine 31 is started, the engine 3
An oil pump (not shown) is driven by the rotation force of 1,
Oil is pumped to each part of the engine 31. Part of the oil is guided from the oil supply path 40 to the convex portions 79a and 79b, which are means for introducing the oil formed inside the oil plate 76 of the sealing device 75, through the opening 40a.

Spaces 80a and 80b are formed between the insides of the protrusions 79a and 79b and the right ball bearing 57R, while openings 64a of the oil introduction passage 64 formed in the right crank journal 43R and the right side. A space 65 is also formed between the ball bearing 57R and the outer surface of the inner race 60. These spaces 65 and 80 are integrated to form an oil sump 96, and the oil is introduced into the oil sump 96.

The oil in the oil sump 96 guides the oil once formed in the center of the right crank journal 43R from the opening 64a of the oil introduction passage 64 which is a means for guiding the oil formed in the right crank journal 43R. The oil is guided to an oil passage 62 serving as a means, and is guided from an oil guide path 66 serving as a means for guiding oil toward the outer peripheral surface of the right crank journal 43R.

According to the present invention, the right crank journal 4
The 3R oil introduction passage 64, oil passage 62, and oil guide passage 66 are not long as in the conventional case and are easy to process.
Cost can be reduced.

Since the edge of the opening 64a on the right ball bearing 57R side of the oil introduction path 64 is provided away from the outer surface of the inner race 60 of the right ball bearing 57R, the right ball bearing 57R is connected to the right crank journal. No galling occurs even when pressed into the 43R, and it is not necessary to perform chamfering on the edge of the opening 64a as in the related art, so that the processing cost can be reduced. And
Since no galling occurs at the time of press-fitting, defective products are reduced and the cost is reduced.

On the other hand, the oil is
Oil inlet 6 which is a means for guiding oil formed in the inside
7 is guided toward the center of the crank pin 45 through an oil guide passage 68 which is a means for guiding other oil. The oil passes through the oil distribution passage 69a, which is a means for distributing the oil from the vicinity of the tip end of the oil guide passage 68 toward the outer peripheral surface of the crank pin 45, to connect the large end portion 4 of the connecting rod.
While being guided to the metal bearing 47, the oil is a means for distributing the oil drilled from the vicinity of the tip end of the oil guide path 68 toward the joint surface between the crank pin 45 and the starter clutch 53. Distribution path 69
It is also guided to the starter clutch 53 via b.

Since the opening 69c of the oil distribution passage 69b led to the starter clutch 53 does not open to the contact surface with the needle bearing 54 as in the prior art, the surface pressure between the needle bearing 54 and the crankshaft 41 is reduced. Will not go up.

On the other hand, in the present invention, the right ball bearing 5
7, a seal device 75 is provided on the right side, and oil is introduced into the crankshaft 41. Therefore, it is not necessary to form an oil guide path with an oil seal as in the related art, and the drive pulley 84 projects to the left side. Never do. As a result, the width of the engine 31 is reduced. In addition, the load on the left ball bearing 57L is reduced, and there is no need to increase the size of the left ball bearing 57L, so that the size of the engine 31 can be reduced as a whole.
Further, since the V-belt 85 approaches the left ball bearing 57L, vibration is also reduced.

By the way, although a part of the oil fed into the sealing device 75 inevitably leaks from the oil seal 77, in the present invention, the sealing device 75 is arranged adjacent to the cam chain drive sprocket 70. Therefore, the cam chain drive sprocket 70 and the cam chain 74 can be sufficiently lubricated by actively utilizing the leaked oil.

In the embodiment described above, an example is shown in which the present invention is applied to a four-stroke engine for a motorcycle.
The present invention is applicable to engines for other uses, and also applicable to a two-cycle engine.

[0077]

As described above, according to the engine lubrication apparatus of the present invention, in an engine lubrication apparatus in which oil is pumped into an engine by an oil pump,
Bearings are press-fitted into the crank journal of the crankshaft, and means for guiding oil from the surface of the crank journal that contacts the bearing toward the crankpin into the crank journal is provided, so that the length is short and machining is easy. Means for guiding the oil can be formed in the crankshaft.

Further, since the oil guiding means has the opening edge facing the bearing away from the outer surface of the bearing, it is possible to prevent galling on the bearing when assembling the crankshaft. .

[0079]

[0080]

[0081]

A cam chain mechanism for driving a valve mechanism is provided on the crankshaft adjacent to the seal device, and the cam chain mechanism is lubricated by oil leaking from the seal device. Can be fully lubricated.

[Brief description of the drawings]

FIG. 1 is a horizontal sectional view of a four-cycle single-cylinder engine unit for a motorcycle, showing one 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.

FIG. 3 is a sectional view taken along the line II of FIG. 2;

FIG. 4 is a sectional view taken along the line II-II of FIG. 2;

FIG. 5 is an enlarged view of the vicinity of an opening of an oil introduction path.

FIGS. 6A and 6B are a plan view and a sectional view taken along line III-III of the sealing device.

FIG. 7 is an arrow view along the line IV-IV in FIG. 2;

FIG. 8 is a horizontal sectional view of a main part of a conventional engine unit.

[Explanation of symbols]

Reference Signs List 30 engine unit 31 engine 32 crankcase 35a, 35b, 35c partition wall 38 cam chain chamber 40 oil supply path 41 crankshaft 42R, 42L crank arm 43R, 43L crank journal 45 crankpin 47 metal bearing 48 connecting rod 49 connecting rod large end 52 piston 53 Starter clutch 54 Needle bearing 57R, 57L Ball bearing 59 Outer race 60 Inner race 62 Oil passage (means for guiding oil) 64 Oil introduction path (means for guiding oil) 66 Oil guide path (means for guiding oil) 67 Oil intake (means for guiding oil) 68 Oil guide path (means for guiding oil) 69a, 69b Oil distribution path (means for distributing oil) 70 Kamche Drive sprocket (cam chain mechanism) 71 Valve train mechanism 74 Cam chain (cam chain mechanism) 75 Seal device 76 Oil plate 77, 95a, 95b Oil seal 79a, 79b Convex portion (means for introducing oil) 80a, 80b (convex) 83) V-belt type automatic transmission 84 drive pulley 85 V-belt 92 alternator 93 cooling fan 96 oil sump

Claims (1)

(57) [Claims] 1. A crankshaft having one end facing a V-belt chamber and another end provided with an alternator is supported by ball bearings on both sides of a crank arm.
In the vicinity of the ball bearing that supports the crankshaft on the side opposite to the belt chamber, there is provided an inlet of an oil passage for feeding oil to the crankpin through the inside of the crankshaft. In a lubricating system for a motorcycle four-stroke engine equipped with a V-belt automatic transmission for lubricating the crankpin by pumping oil from an oil pump, a lubricating device for a four-stroke engine for a motorcycle, A cam chain drive sprocket is provided, an inlet of the oil passage is opened near the cam chain drive sprocket, an oil reservoir is formed between the ball bearing and the cam chain drive sprocket, and the crank pin is formed. The oil that lubricates the oil via this oil sump With the oil that has been pumped by and leaked from the oil pool,
A lubricating device for a motorcycle four-stroke engine, wherein the lubricating device is configured to lubricate a cam chain driven by a cam chain drive sprocket.