JP3104484B2 - Dry sump type motorcycle engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dry sump type motorcycle engine, and more particularly to a dry sump type motorcycle engine having an oil circulation system.

[0002]

2. Description of the Related Art Since an engine has many sliding parts and rotating parts inside, an oil is supplied to each part using a lubricating device, and a frictional resistance of each part is reduced by the action of the oil, and the function of the engine is sufficiently improved. It is designed to demonstrate.

For example, as shown in FIG. 7, the oil flow of a dry sump type lubricating apparatus is as follows. First, oil stored in an oil tank 2 provided separately from the engine 1 is as follows.
The oil is supplied to an oil filter 5 provided in the engine 1 by an oil supply pump 4 constituting a part of an oil circulation device via an oil supply hose 3a. The oil filtered by the oil filter 5 is sent to each lubricating unit in the engine 1 via the oil passage 6 and the like.

[0004] After lubricating each lubricating portion in the engine 1, the oil naturally falls or accumulates in an oil pan 8 via an oil return passage 7 or the like. The oil collected in the oil pan 8 is supplied from an oil intake port 9 immersed in the oil pan 8 to an oil pump 10 constituting another oil circulation device.
And is returned to the oil tank 2 via the oil return hose 3b.

On the other hand, the engine 1 is provided with a clutch mechanism 11 which is a device for connecting and disconnecting the rotational driving force of the engine 1 to a drive system below the transmission mechanism.
Is disposed at the shaft end of a countershaft 13 provided in parallel with the crankshaft 12.

The oil circulation devices 4 and 10 (oil pump and oil supply pump) are generally arranged on the same side as the clutch mechanism 11 in series or in parallel.

[0007]

When the oil circulating device is disposed on the same side as the clutch mechanism, the oil circulating device is disclosed in Japanese Unexamined Patent Publication No. 2-115 to avoid interference with the clutch mechanism.
An oil circulating device must be provided below the engine as disclosed in Japanese Patent Application Laid-Open No. 507/507, or an oil circulating device must be provided at a shaft end of a crankshaft as disclosed in Japanese Patent Application Laid-Open No. 4-298618.

However, when the oil circulation device is provided below the engine, the lower portion of the engine projects downward,
The minimum ground clearance of motorcycles is low. If the entire engine is moved upward instead of lowering the minimum ground clearance, the center of gravity of the vehicle body is also moved upward, which is not preferable.

When the oil circulation device is provided at the shaft end of the crankshaft, the side of the engine projects laterally,
The bank angle becomes small, which is not preferable.

[0010] In either case, the size and weight of the engine are increased.

On the other hand, the oil circulation devices must be linked, but in the case of oil circulation devices arranged in series,
It is difficult to assemble, maintain, and inspect the oil circulation device installed on the back side. Also, in the case of oil circulation devices arranged in parallel, the assembly of drive means for interlocking them becomes complicated.

The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a dry sump type motorcycle engine capable of downsizing the engine.

Another object of the present invention is to provide a dry sump type motorcycle engine in which an oil circulation device can be easily assembled.

Still another object of the present invention is to provide a dry sump type motorcycle engine in which an oil circulation device driving means can be easily assembled.

[0015]

According to a first aspect of the present invention, there is provided a dry sump type motorcycle engine including a crankshaft arranged in a crankcase, wherein the crankshaft is disposed in a crankcase. In a motorcycle engine in which a transmission case is integrally provided on the rear side of a crankcase, and a countershaft and a drive shaft each including a plurality of transmission gears are arranged in the transmission case in parallel with the crankshaft, the crankcase Form a magneto chamber on one side of
While one end of the crankshaft is protruded into the magneto chamber and a flywheel magneto is provided at this end, a clutch mechanism is provided at a shaft end of the countershaft opposite to the magneto chamber, and a drive mechanism of the drive shaft is provided. A drive sprocket provided on the same shaft end as the magneto chamber, and an oil for circulating lubricating oil in the engine in the magneto chamber between the flywheel magneto and the drive sprocket, which is on the opposite side of the clutch mechanism. A pump and an oil supply pump are provided.

In order to solve the above-mentioned problem, an oil circulation device including an oil pump and an oil supply pump is coaxially arranged. Each of the central shafts is detachably connected, and one of the oil circulation devices, for example, an oil pump is connected to the crankcase, and the other oil circulation device, for example, an oil supply pump is connected to the magneto chamber. It is attached to the covering engine cover.

Further, in order to solve the above-mentioned problems,
As described in claim 3, an oil circulation device driving means is disposed between the oil pump and the oil supply pump, and a pump driven sprocket constituting the oil circulation device driving means is provided on the crankcase side. The oil circulation device is fixed to a central shaft of an oil pump, for example, an oil pump.

[0018]

In the present invention having the above construction, the oil pump and the oil supply pump for circulating the lubricating oil in the engine are arranged in the magneto chamber between the flywheel magnet and the drive sprocket on the opposite side of the clutch mechanism. With this arrangement, the engine can be made smaller and more compact.

An oil circulation device including an oil pump and an oil supply pump is coaxially arranged,
The respective central shafts of these oil circulation devices are detachably connected, while one of the oil circulation devices is attached to a crankcase and the other oil circulation device is attached to an engine cover that covers the magneto chamber. The oil circulation device can be easily assembled.

Further, an oil circulating device driving means is disposed between the oil pump and the oil supply pump, and a pump driven sprocket constituting the oil circulating device driving means is provided with an oil circulating device provided on the crankcase side. Since it is fixed to the central shaft of the device, it is easy to assemble the oil circulation device driving means.

[0021]

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

FIG. 1 is a right side view showing an example of a motorcycle to which the present invention is applied.

In FIG. 1, the motorcycle 20 has a body frame 21, and a fuel tank 22 is provided above the body frame 21. Also, the body frame 21
An engine 23 is mounted at the lower center of the vehicle.

A head pipe 24 is provided in front of the body frame 21, and a steering mechanism 25 is provided on the head pipe 24. The steering mechanism 25 includes a front fork 2 that rotatably supports a front wheel 26.
7, a handlebar 28, and the like are provided, and the handlebar 28 is used to steer the front wheel 26 to be rotatable left and right.

On the other hand, a swing arm 30 is pivotally mounted on a pivot shaft 29 erected at the lower center of the vehicle body frame 21 so as to freely swing around the pivot shaft 29, and a rear wheel 31 is pivoted at the rear end of the swing arm 30. Freely supported.

FIG. 2 is a longitudinal sectional view taken along the line AA of FIG. 1, and FIG. 3 is a horizontal sectional view taken along the line BB of FIG. FIG. 4 is a sectional view taken along line CC of FIG. 2, and FIG. 5 is a sectional view taken along line DD of FIG.

1 to 5, an engine 23 mainly includes a crankcase 32, a cylinder block 33, a cylinder head 34, and a cylinder head cover 35.
And the outer shape is composed of

The engine 23 is, for example, an air-cooled four-cycle parallel two-cylinder engine provided with a dry sump type lubricating device. As shown in FIG.
4. A double overhead camshaft (DOHC) for opening and closing these valves 36, 37 by providing two camshafts 38a, 38b for opening and closing the intake valve 36 and the exhaust valve 37 above the valves 36, 37, respectively.
It is provided with a type valve operating mechanism 39.

Camshaft 38a for opening and closing intake valve 36
For example, the camshaft 38b for opening / closing the exhaust valve 37 is disposed on the rear side in the vehicle traveling direction of the motorcycle 20, and is disposed on the front side in the vehicle traveling direction, at right angles to the vehicle traveling direction.

An intake passage 40 and an exhaust passage 41 are provided in the cylinder head 34. A carburetor 42a and an air cleaner 42b as an engine intake system 42 are connected to the intake passage 40. On the other hand, the exhaust passage 41
The exhaust pipe 43 which is the engine exhaust system 43
a and the muffler 43b are connected. Further, an oil tank 44 is disposed behind the air cleaner 42b.

A crankshaft 45 is arranged in the crankcase 32 at right angles to the traveling direction of the motorcycle 20. The crankshaft 45 is formed with a crank web 46 for smooth rotation of the crankshaft 45.

The connecting rod 4 is connected to the crankshaft 45.
7 are connected to each other. Also, connecting rod 47
The piston 49 is connected to the small end portion 47b of the first through a piston pin 48. This piston 49 reciprocates in the cylinder liner 50 fitted in the cylinder block 33 in the vertical direction in the drawing, and the reciprocating stroke is
To the crankshaft 45 to rotate the crankshaft 45.

A transmission case 51 is provided integrally with the rear side of the crankcase 32. In the transmission case 51, as shown in FIG. 3, a transmission mechanism 52 as a primary reduction gear is provided. Further, on the left side of the transmission case 51, for example, a clutch mechanism 53 which is a device for connecting and disconnecting the rotational driving force of the engine 23 to a drive system below the transmission mechanism 52 is provided behind the crankshaft 45 in parallel with the crankshaft 45. At the shaft end of the counter shaft 54.

The driving force from the crankshaft 45 is input to the counter shaft 54 via the clutch mechanism 53. A drive shaft 55 provided in parallel with the counter shaft 54 is provided behind the counter shaft 54. Provided. This drive shaft 5
Reference numeral 5 denotes a drive shaft that outputs a driving force to the rear wheel 31.

A plurality of transmission gears 56 having different diameters are provided on the counter shaft 54 and the drive shaft 55.
The primary deceleration is performed by changing the combination of the transmission gears 56.

As shown in FIGS. 4 and 5, the crankcase 32 is, for example, vertically divided and includes an upper crankcase 32a and a lower crankcase 32b. A crankshaft 45 is provided on the inner side of the split surface between the upper crankcase 32a and the lower crankcase 32b.
Bearings 57 for the counter shaft 54 and the drive shaft 55 are provided, and the shafts 45, 54, and 55 are supported by these bearings 57.

A part of the right side of the drive shaft 55 is shown in FIG.
As shown in FIG.
A drive sprocket 58 is provided at the right end of the projecting drive shaft 55. The drive sprocket 58 is connected via a chain 59 to a driven sprocket (not shown) provided on the rear wheel 31.
The engine 59 is transmitted to the rear wheels 31 by performing secondary deceleration by driving the chains 59 and the like.

A magnet chamber 60 is disposed on the right side of the crankcase 32, that is, on the opposite side of the clutch mechanism 53. A flywheel magneto 60a and a cam chain drive sprocket 61 are provided at the right end of the crankshaft 45 projecting into the magneto chamber 60. Is provided.

On the other hand, the respective camshafts 38a, 38
As shown in FIG. 5, cam sprockets 62a and 62b are respectively provided at one end of 8b, and these cam sprockets 62a and 62b are connected to a cam chain drive sprocket 61 by a cam chain 63. Then, the rotation of the crankshaft 45 is
a, 38b to be transmitted to the cylinder head 34.
The valve operating mechanism 39 provided therein is operated.

FIG. 6 is a plan view of the front side of the lower crankcase 32b, showing a state where the crankshaft 45 is removed.

As shown in FIGS. 4, 5 and 6, the lowermost portion of the lower crankcase 32b is
An oil pan 64 is provided near the center between the counter shaft 54 and the counter shaft 54. The oil pan 64 is
After lubricating the internal lubricating portions, the lubricating portion has a role of temporarily storing engine lubricating oil that falls naturally or returns via an oil return passage 65 formed in the cylinder block 33.

Above the oil pan 64 is an oil inlet 6
6 are provided. A strainer 67 for filtering foreign matter in the oil is provided at the tip of the oil inlet 66, and the strainer 67 is immersed in the oil stored in the oil pan 64.

From the oil intake 66 to the crankcase 32
An oil pumping passage 68 extending toward the right magneto chamber 60 is provided, for example, substantially horizontally. Engine 2
An oil pump 70, which is a part of an oil circulating device 69 for circulating lubricating oil inside, is disposed in a magneto chamber 60 between the flywheel magneto 60a and the drive sprocket 58 located on the opposite side of the clutch mechanism 53. Is done.

The downstream side of the oil pumping passage 68 is connected to an oil pump 70. From the oil pump 70, an oil return hose 72 is connected to the oil tank 44 via an oil discharge passage 71 as shown in FIG.

The magneto chamber 60 is covered by a magneto cover 73 which is an engine cover. Magneto cover 73
An oil supply pump 74, which is another oil circulating device 69 for circulating lubricating oil in the engine 23, is provided coaxially with the oil pump 70 at a position corresponding to the right side of the oil pump 70. Oil supply pump 74
Have an oil supply hose 75 and an oil supply passage 76
, An oil tank 44 is connected as shown in FIG. An oil communication path (not shown) extends from the oil supply pump 74 and is connected to an oil filter 77. From the oil filter 77, an oil passage 78 and the like extend to sliding parts and rotating parts inside the engine 23.

The respective central shafts 70a and 74a of the oil pump 70 and the oil supply pump 74 are connected to each other so as to be freely engaged and disengaged. As shown in FIGS. 2, 3, and 5, a pump driven sprocket 80 as an oil circulation device driving means 79 is provided on a center shaft 70a of the oil pump 70 between the oil pump 70 and the oil supply pump 74. This pump driven sprocket 80 is provided with another oil circulation device driving means 7.
9 is connected to a pump drive sprocket 82 which is another oil circulating device driving means 79 via a pump drive chain 81. The pump drive sprocket 82 is provided alongside the cam chain drive sprocket 82 at the right end of the crankshaft 45 projecting into the magneto chamber 60. The rotation of the crankshaft 45 causes the oil pump 70 and the oil supply pump 74 to operate in conjunction with each other.

Next, the operation of the present embodiment will be described.

The flow of oil in the lubricating device of the engine 23 applied to the present embodiment is as follows. First, the oil stored in the oil tank 44 is driven by the driving force of the engine 23 through the oil supply hose 75 and the oil supply passage 76. The oil is pumped to an oil filter 77 by an oil supply pump 74 which is an oil circulation device 69 operated by. After being filtered by the oil filter 77, the oil is sent to sliding portions and rotating portions in the engine 23 via the oil passage 78 and the like.

The oil that has lubricated the respective lubricating portions in the engine 23 falls naturally, or passes through an oil return passage 65 or the like, and the oil pan 6 at the bottom of the lower crankcase 32b.
Collect in 4.

The oil accumulated in the oil pan 64 is pumped from an strainer 67 and an oil inlet 66 by an oil pump 70, which is another oil circulation device 69 operated by the driving force of the engine 23, through an oil pumping passage 68. Oil return hose 72 from oil discharge passage 71
Is returned to the oil tank 44.

The oil pump 70 is provided with the clutch mechanism 5
3 in a magneto chamber 60 provided on the opposite side, and
The oil supply pumps 74 are respectively provided in magneto covers 73 that cover the magneto chamber 60. As a result, the oil circulation device 69 can be disposed in the dead space between the crankshaft 45 and the counter shaft 54. That is, the oil circulating device 69 does not need to be disposed below the engine 23 or at the shaft end of the crankshaft 45, so that the minimum ground clearance of the motorcycle 20 and the bank angle are not reduced. Then, the size and size of the engine 23 can be reduced.

The central shafts 70a and 74a of the oil circulating device 69 are removably connected to each other, and one of the oil circulating devices 69 is connected to the crankcase 32.
By providing the other oil circulating device 69 on the engine cover, none of the circulating devices 69 is retracted to the rear, so that the oil circulating device 69 can be easily assembled and inspected in the magneto chamber 60, and assembled after maintenance. Become.

Further, in the present invention, since the oil supply pump 74 is detachable from the oil pump 70,
Pump driven sprocket 80 to crankcase 32
The oil circulating device driving means 79 (8) can be fixed to the center shaft 70a of the oil pump 70 provided on the side first.
1, 82), the oil supply pump 7
The mounting of the oil circulating device driving means 79 is facilitated by mounting the oil circulating device driving means 79.

[0054]

As described above, the crankshaft is disposed in the crankcase, the transmission case is integrally provided on the rear side of the crankcase, and the transmission case includes a plurality of transmission gears. In a motorcycle engine having a shaft and a drive shaft arranged in parallel with the crankshaft, a magneto chamber is formed on one side of the crankcase,
While one end of the crankshaft is protruded into the magneto chamber and a flywheel magneto is provided at this end, a clutch mechanism is provided at a shaft end of the countershaft opposite to the magneto chamber, and a drive mechanism of the drive shaft is provided. A drive sprocket provided on the same shaft end as the magneto chamber, and an oil for circulating lubricating oil in the engine in the magneto chamber between the flywheel magneto and the drive sprocket, which is on the opposite side of the clutch mechanism. Since the pump and the oil supply pump are provided, the oil lubrication device does not protrude downward or laterally of the engine, and the size and size of the engine can be reduced.

An oil circulating device composed of an oil pump and an oil supply pump is coaxially arranged, and the central axes of these oil circulating devices are detachably connected to each other. One oil circulation device, for example, an oil pump is connected to the crankcase,
Because the other oil circulation device, for example, an oil supply pump, was attached to the engine cover that covers the magneto chamber,
The assembly of the oil circulation device becomes easy.

Further, in order to solve the above-mentioned problems,
As described in claim 3, an oil circulation device driving means is disposed between the oil pump and the oil supply pump, and a pump driven sprocket constituting the oil circulation device driving means is provided on the crankcase side. The oil circulation device, for example, is fixed to the center shaft of an oil pump, so that the oil circulation device driving means can be easily assembled.

[Brief description of the drawings]

FIG. 1 is a right side view of a motorcycle showing an embodiment of a dry sump type motorcycle engine according to the present invention.

FIG. 2 is a longitudinal sectional view taken along line AA of FIG.

FIG. 3 is a horizontal sectional view taken along line BB of FIG. 1;

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

FIG. 5 is a sectional view taken along line DD of FIG. 2;

FIG. 6 is a plan view of a front side of a lower crankcase.

FIG. 7 is a schematic diagram showing the flow of oil in a dry sump lubrication apparatus.

[Explanation of symbols]

Reference Signs List 20 motorcycle 23 engine 32 crankcase 32a upper crankcase 32b lower crankcase 33 cylinder block 34 cylinder head 44 oil tank 45 crankshaft 51 transmission case 52 transmission mechanism 53 clutch mechanism 54 counter shaft 55 drive shaft 60 magneto chamber 69 oil circulation device Reference Signs List 70 oil pump (oil circulating device) 70a central shaft of oil pumping pump 73 magneto cover (engine cover) 74 oil supply pump (oil circulating device) 74a central shaft of oil supply pump 79 oil circulating device driving means 80 pump driven sprocket Oil circulation device driving means) 81 Pump drive chain (Oil circulation device driving means) 82 Pump drive sp Rocket (oil circulation device drive means)

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Claims (3)

(57) [Claims] 1. A crankshaft is disposed in a crankcase, a transmission case is integrally provided on a rear side of the crankcase, and a countershaft and a driveshaft provided with a plurality of transmission gears in the transmission case are provided. In a motorcycle engine arranged in parallel with a crankshaft, a magneto chamber 60 is formed on one side of the crankcase 32, and one end of the crankshaft 45 is protruded into the magneto chamber 60, and a flywheel is While the magnet 60a is provided, the magneto chamber 6 of the counter shaft 54 is provided.
A clutch mechanism 53 is provided at the shaft end on the opposite side of the drive shaft 55 and the magneto chamber 60 of the drive shaft 55 is provided.
A drive sprocket 58 is provided at the same shaft end as the above, and lubricating oil is injected into the engine 23 in the magneto chamber 60 between the flywheel magneto 60a and the drive sprocket 58 on the opposite side of the clutch mechanism 53. An engine for a dry sump type motorcycle, comprising an oil pump 70 and an oil supply pump 74 for circulation. 2. An oil circulation device 69 comprising an oil pump 70 and an oil supply pump 74 is arranged coaxially, and the respective central shafts 70a, 74a of these oil circulation devices 69 are detachable. While connected, one of the oil circulation devices is connected to the crankcase 32.
The dry sump type motorcycle engine according to claim 1, wherein the other oil circulation device is attached to an engine cover (73) covering the magneto chamber (60). 3. An oil circulating device driving means 79 is arranged between the oil pump 70 and the oil supply pump 74. The pump driven sprocket 80 constituting the oil circulating device driving means 79 is connected to the crankcase 3
The dry sump type motorcycle engine according to claim 2, wherein the engine is fixed to a center shaft of an oil circulation device provided on two sides.