JPH0960683A - Bumper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bumper which easily recover the shortened length and the reduce repulsive force of bump cushion rubber by exchanging it for a new one. SOLUTION: A bumper comprises the first cushion rubber member 12 in which a piston rod 2 is inserted into bump cushion rubber 10A to support it and a cylindrical hole 12b is made in a dumber body side 1 and the second cylindrical cushion rubber member 13 which is removably inserted into the cylindrical hole 12b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shock absorber used for a rear cushion unit which is a rear wheel suspension device of a motorcycle.

[0002]

2. Description of the Related Art As a shock absorber used in a conventional rear cushion unit, for example, Japanese Patent Laid-Open No. 56-9868.
This is disclosed in Japanese Patent Publication No.

As shown in FIG. 7, this is a damper portion 3 consisting of a damper body 1 and a piston rod 2, a spring seat 4 fixed to the outer periphery of the damper body 1 and a spring seat fixed to the end of the piston rod 2. A spring 6 interposed between the two and absorbing the compressive force acting between them;
Having.

Further, 7 and 8 are brackets which are upper and lower vehicle body mounting members of the shock absorber, and the bracket 7 is fixed to the end of the piston rod 2 together with the rubber holding member 9, and the rubber holding member 9 is provided with the spring receiving member. The seat 5 and the bump cushion rubber 10 are attached.

As shown in the figure, the bump cushion rubber 10 is fitted into the end of the piston rod 2 and protrudes toward the damper body 1 so that the end face of the bump cushion rubber 10 faces the end face of the damper body 1.

Therefore, according to this shock absorber, when an axial compressive force acts between the upper and lower brackets 7 and 8, first, the spring 6 contracts and absorbs the compressive force.

On the other hand, when the compressive force becomes excessive, the compressive force cannot be absorbed only by the spring 6, and the piston rod 2 further compresses against the damper body 1. At this time, the bump cushion rubber 10 is pressed. Hits the end face of the damper main body 1 to increase the absorbing load with respect to the bending of the bump cushion rubber 10 in a non-linear manner to smoothly absorb the impact.

On the other hand, in recent years, urethane rubber has been used as the bump cushion rubber 10 in order to further smooth the shock absorption by the bump cushion rubber 10.

Further, the bump cushion rubber 10
The range of action of is not limited to the maximum compression stroke range as in the past, but can be extended to the normal buffer stroke range.

[0010]

However, in the conventional shock absorber as described above, the bump cushion rubber 10 made of urethane rubber always receives a large load, and the excessive frequency of the load causes heat generation. The durability tends to decrease in a short period of time, and specifically, the cushion length decreases and the repulsive force (spring force) against bending decreases, resulting in not only the maximum compression stroke range but also the normal stroke range. However, there is a problem that the absorption capacity becomes insufficient even if it can be applied to the vehicle body and the posture of the vehicle body changes.

In order to solve such a problem, it is desired to replace the bump cushion rubber 10 with a new one, but the bump cushion rubber 10 itself is inserted into the piston rod 2 and integrally assembled. Therefore, the damper part 3 cannot be disassembled, and therefore, there is a disadvantage that the bump cushion rubber 10 cannot be replaced.

The present invention has been made in view of the above problems, and the shock absorber which can easily recover the shortened bump cushion rubber and the reduced repulsive force by replacing the bump cushion rubber with a new one. Aim to get.

It is another object of the present invention to provide a shock absorber capable of easily recovering the shortening of the bump cushion rubber and the reduction of the repulsive force by interposing a spacer.

[0014]

According to a first aspect of the present invention, there is provided a shock absorbing device, which comprises a damper portion composed of a damper main body and a piston rod, and a compression force interposed between the damper main body and the piston rod and acting between them. A bump cushion rubber that is provided at the end of the piston rod so as to face one end surface of the damper body and regulates the compression stroke amount of the piston rod with respect to the damper body. The first cushion rubber member has a cylindrical hole that is penetratingly supported, and a cylindrical second cushion rubber member that is detachably fitted in the cylindrical hole.

According to a second aspect of the present invention, there is provided a shock absorbing device in which a cylindrical second cushion rubber member is fitted in the cylindrical hole through a spacer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, one embodiment of the present invention will be described. FIG. 1 is a sectional view showing a shock absorber of the present invention. Specifically, the external appearance is below the center line. Above the center line, only the portion related to the bump cushion rubber and the spring is shown in cross section.

In FIG. 1, 1 is a damper body, 2
Is a piston rod, and these constitute a damper part 3.

Further, 4 is a spring seat fixed to the damper body 1, 5 is a spring seat fitted into the end of the piston rod 2, and 6 is a spring interposed between the spring seats 4 and 5. Is.

Further, 7 and 8 are brackets which are upper and lower vehicle body mounting members of the shock absorber, and the bracket 7 is fixed to the end of the piston rod 2 together with the rubber holding member 9, and the rubber holding member 9 has the above springs. The seat 5 and the bump cushion rubber 10A are attached.

As shown in the figure, the bump cushion rubber 10A is fitted into the end of the piston rod 2 and protrudes toward the damper body 1 so that the end face of the bump cushion rubber 10A faces the end face of the damper body 1.

A cam surface 4a is formed on the lower edge of the spring seat 4, and the cam surface 4a is engaged with a guide projection 11 fixed to the outer periphery of the lower end of the damper body 1.
The spring receiving member can be moved in the axial direction of the damper main body 1 by bringing any position of the cam surface 4a into contact with the guide protrusion 11.

As a result, the initial repulsive force of the spring can be set arbitrarily.

The rubber holding member 9 holding the spring seat 5 is fixed so that its upper end is sandwiched between the piston rod 2 and the bracket 7, and the spring seat 5 is coaxial with the piston rod 2. I hold it.

Further, as described above, the bump cushion rubber 10 is provided on the piston rod 2 on the rubber holding member 9 side.
A is attached.

This bump cushion rubber 10A is the first
The cushion rubber member 12 and the second cushion rubber member 13 are combined.

Of these, the first cushion rubber member 1
The piston rod 2 is inserted into the shaft core hole 12a of the shaft 2, and one tapered end face 12b is positioned by contacting the tapered face 9a of the rubber holding member 9.

A cylindrical hole 12d is formed in an end portion 12c of the first cushion rubber member 12 on the damper body 1 side, and a cylindrical second cushion rubber member 13 is inserted into the cylindrical hole 12d. Has been done.

Incidentally, this second cushion rubber member 13
Is inserted into the piston rod 2 through its center hole 13e.

Here, the second cushion rubber member 13 is sized so that its lower end (the right end in the figure) projects below the lower end of the first cushion rubber member 12 by a predetermined length.

The second cushion rubber member 13 is used.
The cylinder may have a cylindrical shape as long as it can be easily inserted and inserted into the piston rod 2. However, in order to easily attach and detach the piston rod 12 in the completed state of the damper portion 3, for example, as shown in FIG. It is desirable that the two semi-cylindrical rubber members 13a and 13b are superposed on each other to form a cylindrical shape.

As another embodiment of the second cushion rubber member 13, as shown in FIG. 3, a U-shaped rubber member 13c is bent into a cylindrical shape as shown by a chain line to be used. be able to.

Further, the second cushion rubber member 13
As still another embodiment of the present invention, as shown in FIG.
It is also possible to use a rubber member 13d in which two circular arcs are continuous so as to be folded in the direction shown by the dotted line to have a cylindrical shape.

In the shock absorber having the bump cushion rubber 10A having such a structure, when it is used as a rear cushion unit of a motorcycle as described above, it is subjected to a sudden change in vehicle load or shock, and the damper body When the piston rod 2 compresses with respect to 1, the damper part 3 as a whole contracts and the spring 6 is also compressed.

When the compression energy exceeds the compression force absorption level of the spring 6 and the contraction further progresses, the tip end portion of the second cushion rubber member 13 of the bump cushion rubber 10A becomes the upper end surface of the damper body 1. After being interfered with, it deforms and increases the absorption load in a non-linear manner, and smoothly absorbs the impact.

By the way, when the second cushion rubber member 13 made of urethane rubber or the like, together with the first cushion rubber member 12, the repulsive force is lowered due to the excessive frequency of the load, and the entire length of the bump cushion rubber 10A is shortened. However, the shock absorbing power deteriorates.

In such a case, the second cushion rubber member 13 is pulled out from the cylindrical hole 12d of the first cushion rubber member 12 along the piston rod 2, and is cut off to separate it from the piston rod 2. rear,
Any of the rubber members 13a to 13d shown in FIGS. 2 to 4 is fitted into the cylindrical hole 12d.

That is, the rubber member 13 divided into two parts shown in FIG.
When a and 13b are used, they are joined so as to form a cylindrical shape and straddle the piston rod 2.
In this state, the rubber members 13a and 13b are fitted into the cylindrical hole 12d from their open ends.

The first cushion rubber member 12 is
The rubber holding member 9 and the bracket 7 are fixed to the piston rod 2, and the piston rod 2 is fitted to the piston rod 2.

Thereafter, a piston or the like (not shown) is attached to the piston rod 2 to assemble the damper body 1.

By doing so, the second cushion rubber member 13 having a reduced repulsive force and a reduced overall length can be replaced again with a new one, and the bump cushion rubber 10A can be replaced.
The initial characteristics of the repulsive force as a whole can be restored, and as a result,
It is possible to improve the shock absorbing ability and maintain the body posture at an appropriate level.

Further, the U-shaped rubber member 13c shown in FIG.
Is inserted into the piston rod 2 so as to straddle the piston rod 2 and then a part (end portion) is bent into a cylindrical shape. In this state, the piston rod 2 is inserted into the cylindrical hole 12d.
The U-shaped rubber member 13c can be integrally connected to the first cushion rubber member 12 as the second cushion rubber member 13.

Further, the rubber member 13d shown in FIG. 4 in which two arcs are continuous covers the piston rod 2 by folding the rubber member 13d at the center, and in this state, inside the cylindrical hole 12d. The rubber member 13d can be integrally coupled to the first cushion rubber member 12 as the second cushion rubber member 13 by inserting the rubber member 13d into the first cushion rubber member 12 as described above.

Even when the rubber members 13c and 13d shown in FIGS. 3 and 4 are used, the second cushion rubber member 13 having a reduced repulsive force and a reduced overall length can be replaced with a new one, and repulsed. The initial characteristics of force can be restored, and as a result, appropriate shock absorbing ability can always be obtained and the body posture can be maintained at an appropriate level.

Incidentally, each rubber member 13 shown in FIGS.
a to 13d are cylindrical holes 12d due to overlapping or the like.
Since they have a cylindrical shape inside and are fitted and held by their own elasticity, they do not easily fall out or stick out from the cylindrical hole 12d.

FIG. 5 shows another embodiment of the present invention, in which the first and second cushion rubber members 12, 1 constituting the bump cushion rubber 10B are shown.
When the repulsive force is reduced due to the constant load of No. 3 and the total length is shortened, the bottom portion in the cylindrical hole 12d in which the second cushion rubber member 13 is inserted has a ring-shaped part. In addition, a spacer 15 made of a flexible material such as rubber is interposed.

By doing so, the entire length of the second cushion rubber member 13 can be maintained at a predetermined length by the thickness of the spacer 15, and the lower end of the second cushion rubber member 13 is sufficiently projected to the lower end of the first cushion rubber member 12. The desired repulsive force can be recovered, and the desired shock absorbing function can be easily secured.

Since the spacer 15 has a partly split, it is easy to mount the spacer 15 across the piston rod 2 and the space between the first and second cushion rubber members 12 and 13 is formed in the cylindrical hole 12d. Since it is sandwiched between, there is no need to worry about falling out.

The spacer 15 may be divided into two parts if necessary, and may be made of metal or synthetic resin instead of the flexible member. In this case, the second cushion rubber is used. It is desirable to give the member 13 a sufficient shock absorbing function.

FIG. 6 shows still another embodiment of the present invention. In this case, the bump cushion rubber 10C is attached to the rubber holding member 9 and the piston rod 2 so as to have a small diameter. The second cushion rubber member 13A and the first cushion rubber member 12A having the cylindrical hole 12e and the second cushion rubber member 13A fitted and inserted into the cylindrical hole 12e. .

In this embodiment, the second cushion rubber member 13A is formed by dividing it into two, U-shaped or two arcs which are continuous, and the cylindrical hole 12e of the first cushion rubber member 12A. The desired shock absorbing function can be obtained by removably fitting in the same as the above-mentioned embodiment.

In each of the above embodiments, the first and second cushion rubber members 1 shown in FIGS. 1 and 5 are used.
Although the case where 2 and 13 are formed by using urethane rubber has been described, the first cushion rubber member 12 may be a normal SBR rubber and the second cushion rubber member 13 may be a urethane rubber.

In the bump cushion rubber 10C shown in FIG. 6, the first and second cushion rubber members 12A,
Both 13A can be made of urethane rubber,
One of the first and second cushion rubber members 12A and 13A can be SBR rubber and the other can be urethane rubber.

The present invention is characterized by the structure, and the cushion rubber members 12, 13, 12A,
As the material of 13A, any materials can be selected and used in combination.

As described above, according to the present invention, the bump cushion rubbers 10A, 10B and 10C are composed of the first and second cushion rubber members 12, 12A, 13 and 13A, and the cylindrical holes formed in one of them 12, 12A. 12
The other cushion rubber members 13, 13 in d, 12e
By inserting A, it is possible to recover the sag of the entire length caused by use and the reduction of the repulsive force with respect to the bending displacement by replacing the other cushion rubber member, thereby improving the shock absorbing ability, The body posture can be maintained at an appropriate level.

Further, as shown in FIG. 5, the cylindrical hole 12
By inserting and inserting the second cushion rubber member 13 into the d via the spacer 15, the sunk portion of the entire length of the bump cushion rubber 10B can be assisted by the spacer 15, and the repulsive force of the bump cushion rubber 10B. Can be restored to the initial characteristics.

Further, the second cushion rubber member 13 and the second cushion rubber member 13A are vertically arranged in two.
Cylindrical cushion rubber that can be inserted into the piston rod 2 by dividing it, making it U-shaped, or making two arcs continuous, and symmetrically stacking, bending, or folding them. The member can be easily formed, and therefore the bump cushion rubber 10A, 10
When the total length of B is reduced or the repulsive force is reduced, these can be easily exchanged, and by this exchange, the repulsive force can be recovered and the desired shock absorbing ability can be maintained.

The second cushion rubber member 1 is used.
By optionally selecting the size and shape of 3, 13A, or the thickness of the spacer 15 and exchanging them, cushioning characteristics that meet the vehicle application and user's personal requirements can be easily obtained. Alternatively, it is possible to easily obtain the cushioning characteristics required for each individual cushioner unit.

In a rear cushion unit which requires various bump cushion characteristics depending on the vehicle type, one cushion rubber member of the first and second cushion rubber members is used as a base and the other cushion rubber member is used as a base. If the characteristics required for each vehicle model are to be provided, one of them will be used in common, and the desired cushioning effect will be obtained simply by newly installing only the other cushion rubber member, improving mass production efficiency and improving the cushion rubber member. Can be manufactured at low cost.

Further, when the damper is coated, the cushion rubber member on one side is not completely fitted and inserted into the cushion rubber member on the other side, but is extended to a partially fitted state so that the piston rod 2 is extended. Since it can be covered, the cushion rubber member can be used as a masking material for the piston rod 2 at the time of painting, and masking can be performed only by a simple work of extending the cushion rubber member, which saves masking material costs. The workability is improved, and the manufacturing cost can be reduced.

[0060]

As described above, according to the first aspect of the present invention, the damper portion including the damper body and the piston rod, and the compression force that is interposed between the damper body and the piston rod and acts between them. A bump cushion rubber that is provided at the end of the piston rod so as to face one end surface of the damper body and that regulates a compression stroke amount of the piston rod with respect to the damper body. Is composed of a first cushion rubber member having a cylindrical hole penetratingly supported by the piston rod and a cylindrical second cushion rubber member detachably fitted in the cylindrical hole. To shorten the rubber and reduce the spring force, replace some of these with new ones. There is an effect to be obtained which can easily recover a desired repulsive force and buffering functions by.

According to the second aspect of the invention, since the second cushion rubber member having a cylindrical shape is inserted into the cylindrical hole via the spacer, the bump cushion rubber can be shortened and the spring force can be reduced. There is an effect that a desired spring force can be easily recovered by interposing a spacer against the decrease of the.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a shock absorber according to an embodiment of the present invention.

FIG. 2 is a front view showing an embodiment of a second cushion rubber member shown in FIG.

FIG. 3 is a front view showing another embodiment of the second cushion rubber member of FIG.

FIG. 4 is a front view showing another embodiment of the second cushion rubber member of FIG.

FIG. 5 is a sectional view showing a shock absorber according to another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a shock absorber according to another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a conventional shock absorber.

[Explanation of symbols]

 1 Damper body 2 Piston rod 3 Damper part 6 Spring 10A, 10B, 10C Bump cushion rubber 12, 12A First cushion rubber member 13, 13A Second cushion rubber member 12d, 12e Cylindrical hole 15 Spacer

Claims (2)

[Claims] 1. A damper part composed of a damper body and a piston rod, a spring interposed between the damper body and the piston rod to absorb a compressive force acting therebetween, and one end surface of the damper body facing each other. A bump cushion rubber that is provided at the end of the piston rod and that regulates the amount of compression stroke of the piston rod with respect to the damper body, the bump cushion rubber having a cylindrical hole penetratingly supported by the piston rod. A cushioning device, comprising: a cushion rubber member; and a cylindrical second cushion rubber member that is detachably fitted into a cylindrical hole. 2. A damper part composed of a damper body and a piston rod, a spring interposed between the damper body and the piston rod to absorb a compressive force acting between them, and one end surface of the damper body facing each other. A bump cushion rubber that is provided at the end of the piston rod and that regulates the amount of compression stroke of the piston rod with respect to the damper body, the bump cushion rubber having a cylindrical hole penetratingly supported by the piston rod. A cushioning device, comprising: a cushion rubber member; and a cylindrical second cushion rubber member fitted and inserted into a cylindrical hole via a spacer.