Damping force generating mechanism

Details Damping force generating mechanism Damping force generating mechanism

1998-03-18

2001-02-13

Dickson, Paul N. (Department: 3618)

Land vehicles

Wheeled

Running gear

C280S124177

Reexamination Certificate

active

06186526

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a damping force generating mechanism for generating a damping force by pressing an elastic body.
2. Description of the Background Art
A damping force generating mechanism is used for various portions required for absorbing vibration, for example, used for a so-called bottom link type suspension of a motorcycle in which a front wheel is suspended from lower end portions of a front fork through links. A general example of such a bottom link type suspension is shown in
FIG. 16
(see Japanese Patent Laid-open No. Sho 62-187608).
Referring to
FIG. 16
, there is shown a scooter type motorcycle
01
. A steering shaft
03
is turnably fitted in a head pipe
02
. A pair of right and left front forked portions
04
are integrally mounted on the lower end of the steering shaft
03
. A front wheel
06
is suspended from the lower ends of the front forked portions
04
through rocking arms
05
as link members.
With respect to the rocking arm
05
, the base end thereof is pivotably supported on the lower end portion of the front forked portion
04
, and the free end portion thereof rotatably supports the front wheel
06
. A suspension spring
07
is interposed between the upper portion of the front forked portion
04
and an approximately central portion of the rocking arm
05
.
A shock load applied to the front wheel from irregularities on the ground is damped by the suspension springs
07
. However, when a shock load is applied with an abrupt shock load, the suspension springs are largely rebounded after being contracted once.
In an example described in Japanese Patent Publication No. Sho 57-49432, as shown in
FIG. 17
, a front end of a link
012
is pivotably supported on the lower end portion of a front forked portion
011
containing a hydraulic damping mechanism. A front wheel
013
is rotatably supported on a central portion of the link
012
. A subcushion unit
14
is interposed between the rear end of the link
012
and the central portion of the front forked portion
011
.
The subcushion unit
014
includes a cylindrical main body
015
pivotably mounted on the front forked portion
011
. A piston
016
is slidably inserted in the cylindrical main body
015
and is connected to a leading end of a rod
017
pivotably mounted on the link
012
. A cushion rubber
018
utilized as a damping member is inserted in the cylindrical main body
015
in such a manner as to be mounted on the upper surface of the piston
016
. A stopper rubber
019
utilized as a stopper member is inserted in the cylindrical main body
015
in such a manner as to be mounted on the lower surface of the piston
016
.
The subcushion unit
014
thus generates a compression side damping force by the cushion rubber
018
, and also generates a tensile side damping force by the stopper rubber
019
. Consequently, the subcushion unit
014
can suppress both the bound and rebound of the front wheel
013
.
The above subcushion unit
014
, however, has a disadvantage. Since the piston
016
is slid in the cylindrical main body
015
, and the cushion rubber
018
and the stopper rubber
019
are separately provided on the upper and lower surfaces of the piston
016
, the mechanism is complicated in structure, being heavy and expensive.
SUMMARY OF THE INVENTION
In view of the foregoing, an object of the present invention is to provide an inexpensive damping force generating mechanism capable of generating both a compression side damping force and a tensile side damping force with a simple, lightweight structure.
To achieve the above object, a damping force generating mechanism is provided including an elastic body which generates a damping force when being pressed, and an internal pressure generating member inserted in the elastic body which resists the pressing force.
With this configuration, the mechanism enables a large displacement due to bending deformation of the elastic body and thereby it enables absorption of a sufficient energy. The creep generated upon bending deformation of the elastic body can be reduced by repulsion of the internal pressure generating member inserted in the elastic body accompanied by compressed deformation of the internal pressure generating member. Accordingly, a damping force generating mechanism can be obtained which is capable of reducing the characteristic change due to permanent set. The restoring ability after release of a load is also excellent due to repulsion of the internal pressure generating member.
The internal pressure generating member may comprise a spring member. With this configuration, the creep of the elastic body is reduced by repulsion of the spring member accompanied by the compression thereof. Accordingly, it is possible to make the characteristic change due to permanent set smaller and to enhance the restoring ability.
The internal pressure generating member may comprise a partitioned chamber containing a compressive gas or liquid. With this configuration, the creep of the elastic member is reduced by repulsion of a compressive gas or liquid compressed and deformed together with the partitioned chamber. Accordingly, it is possible to make the characteristic change due to permanent set smaller and to enhance the restoring ability.
The internal pressure generating member may comprise an elastic organic material. The internal pressure generating member, which is made from the organic material, can be easily molded in a shape most suitable for the application. The organic material may have a hollow portion. With this configuration, when the organic material is compressed, a specific repulsive force can be obtained by the presence of the hollow portion. The organic material may be a polyester-urethane based material. With this configuration, it is possible to obtain a specific repulsive force by a large elasticity of a polyester-urethane based material.
To further achieve the object of the invention, a damping force generating mechanism is provided which includes an elastic body which generates a damping force when being pressed, and a restricting wall for suppressing expansion of the elastic body generated in the direction perpendicular to the pressing direction of the elastic body.
When the elastic body is pressed, the expansion of the elastic body in the direction perpendicular to the pressing direction is restricted by the restricting wall. As such, the force of the elastic body applied to the restricting wall becomes larger and the sliding resistance of the elastic body is increased. As a result, a desirable relationship of load to displacement can be easily obtained by the action of the sliding resistance of the elastic body in addition to the elastic characteristic of the elastic body.
The elastic body may be separated from the restricting wall with a gap therebetween at the beginning of pressing of the elastic body, and brought into contact with the restricting wall with progressive pressing of the elastic body.
At the beginning of the pressing, since the elastic body is not brought into contact with the restricting wall due to the gap therebetween, the load is gradually increased with an increase in displacement only by the elastic characteristic of the elastic body. However, as the elastic body is pressed to a state where the elastic body is in contact with the restricting wall, the load is rapidly increased with an increase in displacement by a combination of the sliding resistance of the elastic body and the elastic characteristics of the elastic body. As a result, a desirable relationship of the load to the displacement can be obtained.
The contact area of the elastic body with the restricting wall may be enlarged with further progress of pressing of the elastic body. With this configuration, after the pressed elastic body is brought into contact with the restricting wall, the contact area of the elastic body with the restricting wall is enlarged and thereby the sliding resistance of the elastic body is increased. As a result, a desirable smooth relationship of the inc

Affiliated with

Also associated with

Rating

Damping force generating mechanism does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Damping force generating mechanism, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Damping force generating mechanism will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2570244