JPH07259577A - Engine for vehicle - Google Patents

Abstract

PURPOSE:To easily vary rotational direction of an engine which is mounted on a vehicle. CONSTITUTION:A pilot shaft 38 which is driven by a crank shaft 17 and rotated in a direction opposite to the crank shaft 17 and with the same speed is journalled in a crank case 2. An inter-shaft spacing L1 between the pilot shaft 38 and a counter shaft 28 is equal to an inter-shaft spacing L2 between the crank shaft 17 and the counter shaft 28. A primary drive gear 47 meshed with a primary driven gear 31 provided on the counter shaft 28 is selectively installed on the crank shaft 17 or the pilot shaft 38.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle engine in which the rotation direction of a crankshaft can be switched between forward and reverse directions.

[0002]

2. Description of the Related Art In a small vehicle such as a motorcycle, an engine is often mounted so that a crankshaft is oriented in the vehicle width direction. In this way, when the crankshaft is oriented in the vehicle width direction, it is lightweight due to the torque reaction of the crankshaft, which has a large inertial weight as the engine speed accelerates and decelerates, and the flywheel that is integrally provided with the crankshaft. A pitching moment is generated on the car body.

The direction of such a pitching moment of the vehicle body depends on the rotation direction of the engine (crankshaft).
In other words, when the rotation direction of the crankshaft is switched to normal and reverse,
The direction of the pitching moment is also switched, and the maneuverability and steering stability of the vehicle change.

Thus, by switching the engine rotation direction between forward and reverse, it is possible to make the maneuverability and steering stability different even with the same vehicle body. Therefore, for example, in a motorcycle for racing, the race course and the road surface condition. The engine rotation direction is selected so as to generate a pitching moment in a direction suitable for driving conditions such as.

However, since the rotation direction of the engine cannot be easily switched, conventionally, two engines having different rotation directions are prepared, and one of the engines is selected according to the running condition such as a race course, and the vehicle body is selected. It was installed.

[0006]

However, attaching and detaching a heavy engine to and from the vehicle body is a large-scale work, and many adjustments and inspection works need to be redone when the engine is attached and detached. Takes a lot of trouble.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a vehicle engine in which the engine rotation direction can be easily changed while the engine is mounted on the vehicle. And

Another object of the present invention is to make it possible to change the rotational direction of the engine without complicating the engine structure.

[0009]

To achieve the above object, a vehicle engine according to the present invention has a crankshaft for converting a reciprocating motion of a piston into a rotary motion, and the above crank. In a vehicle engine in which a counter shaft that transmits the rotation of the shaft to a drive system after the drive shaft is pivotally supported in a crankcase, a pilot that is driven by the crankshaft and rotates at the same speed in the opposite direction to the crankshaft. The shaft is supported in the crankcase, the distance between the pilot shaft and the counter shaft is made equal to the distance between the crank shaft and the counter shaft, and a primary drive gear that meshes with the primary driven gear provided on the counter shaft is installed. It can be installed selectively on the crankshaft or pilot shaft.

Further, as described in claim 2, an opening having a size through which the primary drive gear passes is provided at a position corresponding to the primary drive gear of the crankcase, and the opening is liquid-tightly closed. The lid is removable.

Further, as described in claim 3, a balancer shaft for mitigating engine vibration is diverted as the pilot shaft.

[0012]

When the vehicle engine is constructed as described in claim 1, when the primary drive gear is mounted on the crankshaft, the rotation of the crankshaft is directly transmitted to the countershaft, and the countershaft and the crankshaft are mutually connected. Rotate in the opposite direction. Further, when the primary drive gear is mounted on the pilot shaft, the rotation of the crank shaft is not directly transmitted to the counter shaft but is transmitted to the counter shaft via the pilot shaft that rotates at the same speed as the crank shaft and in the opposite direction. Therefore, the counter shaft and the crank shaft rotate in the same direction.

Thus, by selectively mounting the primary drive gear on the crankshaft or the pilot shaft, the rotation direction of the engine (crankshaft) can be easily changed while the engine is mounted on the vehicle. .

According to the vehicle engine of the present invention, the primary drive gear can be easily reassembled from the outside of the crankcase by removing the cover. Therefore, the rotation direction of the engine can be changed more easily.

Further, when the vehicle engine is constructed as described in claim 3, the balancer shaft conventionally provided is used as it is as the pilot shaft.
It is possible to minimize the increase in the number of parts and change the rotation direction of the engine without complicating the engine structure.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a vertical sectional view of a vehicle engine according to the present invention, and FIG. 2 is a horizontal sectional view of the vehicle engine developed along the line II-II in FIG.

The engine 1 is, for example, a parallel two-cylinder two-cycle engine mounted on a motorcycle.
The left side of the center is the front side, and the cylinder assembly 3 is provided on the upper part of the crankcase 2 located at the lower part of the engine 1 while leaning forward. Cylinder assembly 3 above
The cylinder base 4, the cylinder block 5, and the cylinder head 6 are fixed to the upper part of the crankcase 2 in order.

Inside the cylinder block 5, a cylindrical cylinder bore 7 is formed, and a plurality of scavenging ports 8 and an exhaust port 9 opening to the lower front are formed. On the other hand, the cylinder head 6 has the cylinder bore 7
Is provided with a combustion chamber 11 which is aligned with the above, and a water jacket 12 is formed around the combustion chamber 11 and the cylinder bore 7.

A reed valve housing 14 containing a reed valve device 13 is provided at the rear of the cylinder base 4, and a carburetor (not shown) is connected to the free end of an inlet pipe 15 connected to the outside thereof.

A piston 16 is slidably inserted in the cylinder bore 7. On the other hand, a crankshaft 17 extending in the vehicle width direction is rotatably supported in the crankcase 2 by bearings 18, 19 and 20, and a piston pin 22 provided on the piston 16 and the crankshaft 17 are provided. A crank pin 24, which is eccentrically provided on the crank wheel 23, is connected by a connecting rod 25.

Therefore, the reciprocating motion of the piston 16 in the cylinder bore 7 is converted into the rotational motion of the crankshaft 17 by the connecting rod 25, and becomes the output of the engine 1. A flywheel 26, which smoothens the rotation of the crankshaft 17, is integrally provided at the left end of the crankshaft 17.

In the crankcase 2, a counter shaft 28 is rotatably supported by bearings 29 and 30 in parallel with the crankshaft 17. A primary driven gear 31 is rotatably provided on the counter shaft 28, and a multi-plate clutch mechanism 32 is mounted on the outside thereof. The primary driven gear 31 is rotationally integrated with the counter shaft 28 via the clutch mechanism 32 when the clutch mechanism 32 is operated to be connected.

A drive-side multi-stage gear 34 of a transmission 33 is mounted on the counter shaft 28, and the drive-side multi-stage gear 34 is rotatably supported in parallel with the counter shaft 28 (see FIG. 1). (Indicated in (1)) is engaged with the driven-side multistage gear 36 mounted on the shaft.
A drive sprocket (not shown) is further provided on the drive shaft 35, and a chain is wound between the drive sprocket and the driven sprocket provided on the rear wheel of the motorcycle. Therefore, the rotation of the counter shaft 28 is transmitted to the drive system (drive sprocket, chain, driven sprocket ...) After the drive shaft 35 after being changed by the transmission 33, and then transmitted to the rear wheels.

Further, a pilot shaft 38 is provided in the crankcase 2 in parallel with the crankshaft 17 and the counter shaft 28.
It is rotatably supported by 9, 40, 41. This pilot shaft 38 is a balancer shaft for engine vibration mitigation, which is used as it is. It has two eccentric weights 42 and 43 formed to have a relative angle of 180 °, for example, and has a right end portion of the pilot shaft 38. A pilot driven gear 44 is provided integrally therewith by means of spline fitting.

On the other hand, the crankshaft 17 has a pilot drive gear having the same number of teeth as the pilot driven gear 44.
45 is also integrally spun by rotation by spline fitting, and this pilot drive gear 45 meshes with the pilot driven gear 44. Therefore, when the crankshaft 17 rotates, the pilot shaft 38 rotates at the same speed in the opposite direction to the crankshaft 17, and the eccentric weights provided on the pilot shaft 38 rotate.
Due to the eccentric rotation of 42 and 43, the vibration (engine vibration) accompanying the rotation of the crankshaft 17 is mitigated.

Now, as shown in FIG. 1, the pilot shaft 38
The distance L1 between the counter shaft 28 and the counter shaft 28 is equal to the distance L2 between the crank shaft 17 and the counter shaft 28. And
A primary drive gear 47 can be attached to the rightmost ends of the crankshaft 17 and the pilot shaft 38. The primary drive gear 47 is, for example, fitted to the same spline as the pilot driven gear 44 and the pilot drive gear 45, and a washer 48 is applied to fix the bolt 49.
When it is fastened, the crankshaft 17 or the pilot shaft 38 is integrally rotated and meshes with the primary driven gear 31 of the counter shaft 28.

Although FIGS. 1 and 2 show a state in which the primary drive gear 47 is attached to both the crankshaft 17 and the pilot shaft 38, the primary drive gear 47 is either the crankshaft 17 or the pilot shaft 38. It is selectively installed on either side.

Since the axial distance L1 between the pilot shaft 38 and the counter shaft 28 is equal to the axial distance L2 between the crank shaft 17 and the counter shaft 28, the primary drive gear 47 is connected to the crank shaft 17 or the pilot shaft. Whichever of the shafts 38 is mounted, the primary drive gear 47 meshes with the primary driven gear 31 and transmits the rotation of the crank shaft 17 or the pilot shaft 38 to the counter shaft 28.

As shown in FIG. 3, for example, when the primary drive gear 47 is mounted on the crankshaft 17, the spacer 50 is interposed on the pilot shaft 38 on which the primary drive gear 47 is not mounted, and the washer 48 is applied. Tighten the fixing bolt 49. As a result, the movement of the pilot driven gear 44 provided on the pilot shaft 38 in the axial direction is restricted. When the primary drive gear 47 is mounted on the pilot shaft 38, the spacer 50 is provided on the crankshaft 17 to restrict the movement of the pilot drive gear 45 in the axial direction.

Since FIG. 2 is a development view taken along the line II-II in FIG. 1, the primary drive gear 47 mounted on the pilot shaft 38 is the primary driven gear of the counter shaft 28.
Although not shown in mesh with 31, it actually meshes with the primary driven gear 31.

By the way, as shown in FIG. 2 and FIG. 4 which is a view taken in the direction of arrow IV in FIG. 2, the size of the primary drive gear 47 passing through the right side portion of the crankcase 2 at a position corresponding to the primary drive gear 47. An opening 52 is provided, and a lid 53 that liquid-tightly closes the opening 52 is detachably provided. The lid 53 is fixed to the crankcase 2 with four screws 54, for example. To attach and detach the primary drive gear 47, loosen the screw 54 and
Perform by removing 53.

In the engine 1 thus constructed, if the primary drive gear 47 is mounted on the crankshaft 17 as shown in FIG. 5, the rotation of the crankshaft 17 is directly transmitted to the primary driven gear 31 via the primary drive gear 47. Thus, the counter shaft 28 and the crank shaft 17 rotate in opposite directions. In this case, the engine is one in which the crankshaft 17 rotates counterclockwise.

If the primary drive gear 47 is mounted on the pilot shaft 38 as shown in FIG.
Rotation is not directly transmitted to the counter shaft 28,
It is transmitted to the counter shaft 28 via the pilot shaft 38 that rotates in the opposite direction at the same speed as 17. Therefore, the counter shaft 28 and the crank shaft 17 rotate in the same direction. In this case, the crankshaft 17
Becomes an engine that rotates clockwise (the rotation direction of the counter shaft 28 is always clockwise).

As described above, by selectively mounting the primary drive gear 47 on the crankshaft 17 or the pilot shaft 38, the rotation direction of the crankshaft 17, that is, the engine 1
The rotation direction of the engine can be easily changed, and the torque reaction generated by the crankshaft 17 and the flywheel 26, which have large inertial weight as the engine speed accelerates and decelerates, that is, the direction of the pitching moment generated in the motorcycle body. It is possible to change the maneuverability and steering stability of the motorcycle by switching between normal and reverse.

Since the primary driven gear 31 and the primary drive gear 47 are provided outside the inner space of the crankcase 2 (on the right side in the case of this embodiment), the engine 1 (crankcase 2) is entirely covered by the reassembling work. Engine 1
It is possible to easily change the rotation direction of the engine 1 while the vehicle is mounted on the motorcycle. Moreover, the primary drive gear 47 can be reassembled very easily from the outside of the crankcase 2 by removing the lid 53 of the opening 52 provided in the crankcase 2.

Further, in this engine 1, since the balancer shaft for mitigating engine vibration which has been conventionally provided is also used as the pilot shaft 38, the rotation direction can be changed without complicating the structure of the engine 1. It is an engine. Not only the balancer shaft but also the main shaft of the generator, the shaft of the gear train, or the like may be used as the pilot shaft.

By the way, the present invention is not limited to the motorcycle engine shown in the above embodiment, but can be applied to other types of vehicles such as automobiles and buggy vehicles. Further, the present invention is not limited to a two-cycle engine, but can be applied to another type of engine such as a four-cycle engine or a rotary engine. Furthermore, the present invention may be applied to a power unit or the like that uses an electric motor as a power source.

[0038]

As described above, the vehicle engine according to the present invention is provided with a crankshaft for converting the reciprocating motion of the piston into a rotary motion, and a counter for transmitting the rotation of the crankshaft to a drive system after the drive shaft. In a vehicle engine in which a shaft is pivotally supported in a crankcase, a pilot shaft driven by the crankshaft and rotating at the same speed in a direction opposite to the crankshaft is pivotally supported in the crankcase, and the counter shaft is The pilot shafts have the same axial distance from the crank shafts, and a primary drive gear that meshes with a primary driven gear provided on the counter shaft can be selectively mounted on the crank shafts or the pilot shafts. .

Therefore, if the primary drive gear is mounted on the crankshaft, the rotation of the crankshaft is directly transmitted to the countershaft, and the countershaft and the crankshaft rotate in opposite directions. If the primary drive gear is mounted on the pilot shaft, the rotation of the crank shaft is not directly transmitted to the counter shaft but is transmitted to the counter shaft via the pilot shaft that rotates at the same speed as the crank shaft and in the opposite direction.
The counter shaft and the crank shaft rotate in the same direction.

As described above, by selectively mounting the primary drive gear on the crankshaft or the pilot shaft, the rotation direction of the engine can be easily changed while the engine is mounted on the vehicle.

Further, in the vehicle engine according to the present invention, an opening having a size through which the primary driven gear passes is provided at a position corresponding to the primary driven gear of the crankcase, and a lid for liquid-tightly closing the opening is provided. Since it is detachably provided, the primary drive gear can be easily rearranged from the outside of the crankcase by removing the lid portion, and the rotation direction of the engine can be changed more easily.

Further, the vehicle engine according to the present invention is
Since the balancer shaft for mitigating engine vibration is diverted as the pilot shaft, an increase in the number of parts can be suppressed to a minimum, and the rotation direction of the engine can be changed without complicating the engine structure.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a vehicle engine showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the vehicle engine developed along the line II-II in FIG.

FIG. 3 is an enlarged view of a primary drive gear mounting portion.

FIG. 4 is a right side view of the crankcase taken along the line IV of FIG.

FIG. 5 is an operation diagram of the engine when the primary drive gear is mounted on the crankshaft.

FIG. 6 is an operation diagram of the engine when the primary drive gear is mounted on the pilot shaft.

[Explanation of symbols]

 1 engine 2 crankcase 3 cylinder assembly 7 cylinder bore 11 combustion chamber 16 piston 17 crankshaft 25 connecting rod 26 flywheel 28 counter shaft 31 primary driven gear 35 drive shaft 38 pilot shaft 44 pilot driven gear 45 pilot drive gear 47 primary drive gear 52 opening 53 Lid L1 Distance between pilot shaft and counter shaft L2 Distance between crank shaft and counter shaft

Claims (3)

[Claims] 1. A vehicle engine in which a crank shaft for converting reciprocating motion of a piston into rotary motion and a counter shaft for transmitting the rotation of the crank shaft to a drive system after a drive shaft are axially supported in a crank case. A pilot shaft driven by the crank shaft and rotating at the same speed in the opposite direction to the crank shaft is rotatably supported in the crank case, and the distance between the pilot shaft and the counter shaft is determined by the crank shaft and the counter shaft. An engine for a vehicle, wherein a primary drive gear that is equal to the distance between the two and is meshed with a primary driven gear provided on the counter shaft can be selectively mounted on the crankshaft or the pilot shaft. 2. An opening having a size through which the primary drive gear passes is provided at a position of the crankcase corresponding to the primary drive gear, and a lid for removably closing the opening is detachably provided. The vehicle engine according to 1. 3. The vehicle engine according to claim 1, wherein a balancer shaft for damping engine vibration is diverted as the pilot shaft.