JPH0558373A - Motorcycle - Google Patents

Abstract

PURPOSE:To prevent the occurrence of hopping without incurring of a power loss during normal running while complication of a maintenance work and the increase of the size of an engine are suppressed, in a motorcycle formed in such a way that a rear shock absorber is located between a car body frame and a rear swing arm. CONSTITUTION:A damper device 10 to generate a damping force when a rear swing arm 3 is rocked downward from a spot in the vicinity of an static IG position is located between a car body frame 2 and the rear swing arm 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle, and more particularly to a motorcycle having a rear suspension unit interposed between a body frame and a rear swing arm.

[0002]

2. Description of the Related Art When driving a motorcycle of this type,
For example, it is well known that when the engine brake is suddenly applied, the phenomenon that the rear wheel vibrates like bouncing, that is, so-called hopping occurs. Since this phenomenon is caused by the natural vibration of the motorcycle, the setting of the rear suspension unit cannot handle it. Therefore, in a conventional motorcycle, a back torque releasing device equipped with a one-way clutch is incorporated in the engine, specifically in the middle of a power transmission system connecting the engine and the rear wheels, and when the engine brake is applied, the rear wheels are provided. By releasing the generated back torque, the occurrence of hopping is prevented in advance.

[0003]

By the way, the back torque releasing device becomes a dead weight except when the engine brake is operated. Therefore, in the conventional motorcycle having the device in the power transmission system, the usual dead weight is not provided. There was the inconvenience of causing power loss during driving. Further, in the above-mentioned conventional motorcycle, not only the maintenance work related to the back torque releasing device becomes extremely complicated, but also
Incorporating the back torque release device into the engine causes a problem of increasing the size of the engine. In view of the above-mentioned circumstances, the present invention is capable of preventing the occurrence of hopping in advance without causing power loss during normal traveling, while also suppressing the complexity of maintenance work and the increase in size of the engine. The purpose is to provide a motorcycle.

[0004]

Therefore, in the motorcycle according to the present invention, between the body frame and the rear swing arm, the rear swing arm swings downward from the position occupied in the static 1G state. The above object is achieved by interposing a damper device that generates a damping force when it moves.

[0005]

According to the above construction, the careless vibration of the rear swing arm when the engine brake is applied is suppressed by the operation of the damper device, and the vibration of the rear wheels is prevented from occurring.

[0006]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments. 1 to 3 show an embodiment of a motorcycle according to the present invention. The motorcycle 1
Is a vehicle body frame 2 on which the engine E is mounted, a rear swing arm 3 supported by the vehicle body frame 2, rear wheels 4 supported by the rear swing arm 3, the vehicle body frame 2 and the rear swing arm 3. The rear suspension unit 5 is interposed between the rear suspension unit 5 and the rear suspension unit 5.

As clearly shown in FIG. 2, the rear swing arm 3 is swingably supported by a body frame 2 via a pivot 6 and a rear cushion lever 7 is provided.
The rear cushion lever 7 and the rear swing arm 3 are connected to each other via a rear cushion rod 8.

Also, the rear suspension unit 5
Has its upper end 5A supported by the vehicle body frame 2 via a bracket 2A, while its lower end 5B is connected to the rear cushion lever 7. That is, the rear suspension unit 5 is installed so as to be interposed between the vehicle body frame 2 and the rear swing arm 3 via the rear cushion lever 7 and the rear cushion rod 8.

On the other hand, as clearly shown in FIGS. 1 and 2, a damper device 10 is provided between the vehicle body frame 2 and the rear cushion lever 7, and the end portion of the main body 10A of the damper device 10 is the above-mentioned. While being supported by the vehicle body frame 2, the end portion of the rod 10B is supported by the rear cushion lever 7. That is, the damper device 1
0 is installed so as to be interposed between the vehicle body frame 2 and the rear swing arm 3 via the rear cushion lever 7 and the rear cushion rod 8.

As shown in FIG. 3, the damper device 10 has a tapered orifice rod 10a provided on a body 10A and a recess 1 provided on a rod 10B.
0b forms an orifice, and the rod 10B is provided with a throttle passage 10c. In addition,
Reference numeral 10C is a reservoir tank.

As is apparent from the graph of damping force characteristics shown in FIG. 4, the damper device 10 is a so-called position-dependent damper device in which the damping force is generated in the middle of the compression stroke and gradually increases. is there. The vertical axis in the graph of FIG. 4 is the damping force, the horizontal axis is the stroke of the rod 10B, the point Sa on the horizontal axis is the most extended position of the rod 10B, the point Sb is the most contracted position of the rod 10B, and the point Sc is the damping point. The position of the rod 10B at which the force starts to be generated is shown.

The rear swing arm 3 of the motorcycle 1 swings between the lowest position shown by the solid line in FIG. 2 and the highest position shown by the three-dot chain line, while the operator rides on a flat road. When the vehicle is traveling at a constant speed, that is, when the traveling condition is the static 1G state, the rear swing arm 3 is moved to the position indicated by the one-dot chain line in FIG.
The position is called G position).

On the other hand, the damper device 10 also operates with the swing of the rear swing arm 3, and when the rear swing arm 3 swings downward, the rod 10B of the damper device 10 compresses (retracts). Stroke in the direction. Further, when the rear swing arm 3 is occupied at the 1G position described above, the rod 10B of the damper device 10 is located at the point Sc in FIG. 4, and the rear swing arm 3 is located at the 1G position and the maximum position. When swinging between the lower position (ΔR in FIG. 2), the rod 10B of the damper device 10 strokes in the range on the compression side from the point Sc, as indicated by ΔS in FIG.

That is, the rear swing arm 3 is 1
Only when the damper device 10 is swung downward from the G position, the damper device 10 generates a damping force, so that FIG.
As is clear from the graph of damping force characteristics of the rear swing arm 3 shown in FIG.
, The damping force of the damper device 10 acts only when it is swung downward from the 1G position. The vertical axis in the graph of FIG. 5 represents the damping force, and the horizontal axis represents the swing range of the rear swing arm 3. The point Ra on the horizontal axis is the uppermost point of the rear swing arm 3, and the point Rb is the rear swing arm 3. The lowest point, point Rc, indicates the 1G position of the rear swing arm 3.

The rear swing arm 3 which has been occupied at the 1G position by applying the sudden enn brake now
If a force that rapidly swings the
Since the damping force of the damper device 10 acts on the rear swing arm 3 as described above, the rear swing arm 3 is prevented from being inadvertently vibrated, so that hopping is prevented from occurring. On the other hand, as described above, in the damper device 10, the rear swing arm 3 is
Since it acts only when it swings below the position, it does not affect the shock absorption of the rear suspension unit in a normal running state, in other words, the steering stability.

As described above, the motorcycle 1 having the above structure
According to this, since the occurrence of hopping during engine braking can be prevented in advance, it becomes possible to plunge deeply during cornering, and thus extremely good steering stability can be obtained. Further, according to the motorcycle 1 having the above-mentioned configuration, it is possible to effectively prevent so-called chattering in which the rear wheel slightly vibrates to the left and right during cornering, so that good steering stability can be obtained. ..

By the way, in place of the damper device 10 in the motorcycle 1 described above, it is possible to employ a damper device 20 having a structure as shown in FIG. The damper device 20 includes a main body 20A and a rod 20B. A plurality of throttle passages 20a, 20b, 20c are formed on the peripheral wall of the main body (body) 20A, the inner diameters of which are successively reduced along the compression stroke direction of the rod 20B. , 20d are arranged, while the piston of the rod 20B has a one-way valve 2
0e is attached. Reference numeral 20C in the figure is a reservoir tank. The damper device 20 is also a position-dependent damper device having the same damping force characteristics (FIG. 4) as the damper device 10 described above, and a motorcycle equipped with the damper device 20 is similar to the motorcycle 1 described above. Therefore, the occurrence of hopping can be prevented.

In the embodiment shown in FIG. 7, a damper device 30 is provided above the rear swing arm 3, and the end of the main body 30A of the damper device 30 is supported by the vehicle body frame 2 while the rod device 30 is supported. An end portion of 30B is supported by the rear swing arm 3 and is installed so as to be interposed between the body frame 2 and the rear swing arm 3. The configuration other than the damper device 30 is the same as in FIG.
Since the structure of the motorcycle 1 shown in 2 is basically the same,
Constituent elements having the same functions as those of the motorcycle 1 are designated by the same reference numerals as those of the motorcycle 1, and detailed description thereof will be omitted.

As shown in FIG. 8, the piston 30C of the rod 30B of the damper device 30 is formed with a communication passage 30a connecting the left and right pressure chambers, and a subspring 30b mounted on the main body 30A.
A check valve 30c is provided to close the communication passage 30a by abutting against it, and an orifice passage 30d connecting the left and right pressure chambers is formed at the end of the rod 30B. Reference numeral 30e in the drawing is an air chamber.

As is clear from the graph of damping force characteristics shown in FIG. 9, this damper device 30 is so-called position-dependent damper device constructed so that the damping force is rapidly generated from the middle of the pulling stroke. Is. In the graph of FIG. 9, the vertical axis represents damping force and the horizontal axis represents rod 30B.
Is the stroke of the rod 30 and the point Sa on the horizontal axis is the rod 30.
The most extended position of B, the point Sb is the most contracted position of the rod 30B, the point S
c indicates the position of the rod 30B at which the damping force begins to be generated.

When the rear swing arm 3 swings downward, the rod 30B of the damper device 30 makes a stroke in the pulling (stretching) direction, and the rear swing arm 3 moves to the 1G position (see FIG. 7). 9 is located at the point Sc in FIG. 9 when occupied by the one-dot chain line), and the rear swing arm 3 swings between the 1G position and the lowest position (ΔR in FIG. 7). As shown by ΔS at point Sc
Stroke in the range closer to the pull side. That is, the damper device 30 generates a damping force only when the rear swing arm 3 swings below the 1G position, and as is clear from the graph of damping force characteristics shown in FIG. , The above rear swing arm 3
In the above, the damping force of the damper device 30 acts only when it is swung downward from the 1G position. The vertical axis in the graph of FIG. 10 represents the damping force, and the horizontal axis represents the swing range of the rear swing arm 3. Point Ra on the horizontal axis is the uppermost position of the rear swing arm 3, and point Rb is the rear swing arm 3. The lowest point, Rc, is 1G of the rear swing arm 3.
The position.

According to the above-mentioned structure, like the motorcycle 1 shown in FIGS. 1 and 2, when a sudden enn brake is applied,
Even if a force that rapidly swings the rear swing arm 3 is generated, the damping force of the damper device 30 acts on the rear swing arm 3 as described above, so that the occurrence of hopping is prevented. It

In the damper device 10 shown in FIG. 3, the taper of the orifice rod 10a is reversed, that is, the tip on the right side in the tip view is formed thicker than the base end.
As shown in Fig. 5, a damping device of the position dependent type is constructed in which the damping force is generated in the middle of the pulling stroke and gradually increases.
By interposing this between the body frame and the rear swing arm like the damper device 30 described above,
It goes without saying that the occurrence of hopping can be prevented. Further, the arrangement mode of the throttle passages 20a to 20d in the damper device 20 shown in FIG. 6 and the action direction of the one-way valve are reversed, and a position-dependent damper device having a damping force characteristic as shown in FIG. May be configured and mounted like the damper device 30. Further, by disposing the check valve 30c and the sub-spring 30b of the damper device 30 shown in FIG. 8 so as to act when the rod 30B is retracted, the damping force is increased during the compression stroke as shown in FIG. A position-dependent damper device that is suddenly generated from the
Similarly to the damper device 20, by interposing between the vehicle body frame and the rear swing arm, it is possible to prevent the occurrence of hopping.

[0024]

As described above in detail, in the motorcycle according to the present invention, between the body frame and the rear swing arm, the rear swing arm is located below the position occupied in the static 1G state. A damper device that generates a damping force when it swings to is interposed, and by the action of the damper device, inadvertent vibration of the rear swing arm when the engine brake is applied is suppressed, so that hopping occurs in advance. To prevent. That is, according to the motorcycle according to the present invention, the back torque releasing device including the one-way clutch, which is interposed in the power transmission system in the conventional motorcycle, is not required, which causes a power loss during normal traveling. It is also possible to prevent the occurrence of hopping while suppressing the maintenance work from becoming complicated and making the engine larger.

[Brief description of drawings]

FIG. 1 is an overall side view conceptually showing a motorcycle according to the present invention.

FIG. 2 is a conceptual side view of essential parts showing the vicinity of a rear swing arm.

FIG. 3 is a sectional side view showing a damper device.

4 is a graph showing damping force characteristics in the damper device of FIG.

FIG. 5 is a graph showing damping force characteristics of a rear swing arm.

FIG. 6 is a cross-sectional side view showing another damper device.

FIG. 7 is a side view of a conceptual main part around a rear swing arm showing another mode of mounting the damper device.

FIG. 8 is a cross-sectional side view showing another damper device.

9 is a graph showing damping force characteristics of the damper device of FIG.

10 is a graph showing damping force characteristics of the rear swing arm of FIG.

FIG. 11 is a graph showing damping force characteristics of another damper device.

FIG. 12 is a graph showing damping force characteristics of another damper device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Body frame, 3 ... Rear swing arm, 4 ... Rear wheel, 5 ... Rear suspension unit, 10, 20, 30 ... Damper device.

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[Procedure amendment]

[Submission date] November 15, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

Therefore, in the motorcycle according to the present invention, a damping force is generated between the body frame and the rear swing arm when the rear swing arm swings downward from the vicinity of the static 1G position. The above object is achieved by interposing a damper device that generates

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

As described above, the motorcycle 1 having the above structure
According to this, since the occurrence of hopping during engine braking can be prevented in advance, it becomes possible to plunge deeply during cornering, and thus extremely good steering stability can be obtained. Further, according to the motorcycle 1 having the above-mentioned configuration, it is possible to effectively prevent so-called chattering in which the rear wheel slightly vibrates to the left and right during cornering, so that good steering stability can be obtained. .. By the way, the rear swing arm 3 is shown by the one-dot chain line in FIG. 2 due to the difference in various conditions such as the weight of the operator and the fuel loading amount even under the static 1G traveling condition. Needless to say, it is occupied at a position displaced downward or upward relative to the 1G position. Correspondingly, the rear swing arm 3 of the damper device 10 shown in FIG.
Near the static 1G position shown inside, that is, the static 1G
It is configured to generate a damping force when it swings downward from the range displaced up and down with respect to the position, as shown in FIG.
Also, in the motorcycle 1 shown in FIG. 2, when the rear swing arm 3 is located below the static 1G position shown in FIG. 2 due to the light weight of the operator, the static 1G The above damper device 1 even under running conditions
When 0 acts and the rear swing arm 3 tries to swing further downward due to sudden engine braking, hopping is prevented in advance by the damping force generated by the damper device 10. Becomes

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0024

[Correction method] Change

[Correction content]

[0024]

As described above in detail, in the motorcycle according to the present invention, when the rear swing arm swings downward from the vicinity of the static 1G position between the body frame and the rear swing arm. A damper device that generates a damping force is interposed, and due to the action of the damper device, inadvertent vibration of the rear swing arm when the engine brake is applied is suppressed, thereby preventing occurrence of hopping. That is, according to the motorcycle according to the present invention, the back torque releasing device including the one-way clutch, which is interposed in the power transmission system in the conventional motorcycle, is not required, which causes a power loss during normal traveling. It is also possible to prevent the occurrence of hopping while suppressing the maintenance work from becoming complicated and making the engine larger.

Claims (1)

[Claims] 1. An automatic system comprising: a rear swing arm that is swingably supported by a body frame to support rear wheels; and a rear suspension unit interposed between the body frame and the rear swing arm. A two-wheeled vehicle, wherein between the body frame and the rear swing arm,
A motorcycle characterized in that a damper device is interposed which generates a damping force when the rear swing arm swings below a position where it is occupied in a static 1G state.