JPH11210805A - Bump stopper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a bump stopper from dropping off from a stopper body by normally moving a dust cover by equalizing the elastic deformation of the stopper body in the bump stopper comprising the stopper body, which is made from an elastic expansion section, covered by a dust cover. SOLUTION: In a bump stopper wherein a damper 9 moves on the rod shaft of a damper rod 7 resulted from receiving external impact force and abuts on a free end 25, resulting in compressing and deforming an expansion section 24, which restricts the motion of the damper 9 for absorbing and damping the external impact force, and a dust cover 10 covers the cover attaching section 26 projectedly and ring-likely provided in the external periphery of the expansion section 24, the bump stopper is prevented from dropping from a cover mounting section 26 by normally moving the dust cover 10 along and in parallel with a rod axis line C-C by fitting and holding a loop ring-shaped restricting ring 30, which restricts and equalizes the elastic deformation in the expansion section 24, near the cover attaching section 26 in the external periphery of the expansion section 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bump stopper for damping the operation of a movable rod such as a stradd rod in a vehicle suspension mechanism.

[0002]

2. Description of the Related Art FIG. 2 is a sectional view showing an example of this type of bump stopper. The main body 2 of the bump stopper 1 is entirely formed into a bellows-like cylindrical body by an elastic material such as rubber, and a rod 7 such as a straddle rod whose inner center is indicated by an imaginary line in a vertical direction in the drawing is inserted therethrough. The upper ends of the stopper body 2 and the rod 7 are fixedly attached to a vehicle body (not shown) via an upper sheet 8. The upper end portion of the stopper body 2 on the vehicle body fixed side is a rod fitting portion with a fitting hole 3 into which the rod 7 fits with a tightening margin. The lower part of the stopper body 2 is formed as a bellows-like elastic part 4 which is elastically expandable and contractible, and the lower end of the elastic part 4 penetrates the rod 7 without interference in a loosely fitted state. Free end 5.

[0003] At a position below the stopper body 2, a damper 9 is mounted around the axis of the rod 7. The damper 9 moves up and down due to the unevenness of the road surface while the vehicle is running, and the upper flange 9a is brought into contact with the lower end free end 5 of the expansion and contraction portion 4 so as to restrict the further upward movement of the damper 9 indicated by the arrow. The impact force from the road surface is absorbed by the elastic expansion and contraction of the expansion and contraction section 4 in cooperation with the damper 9 to cushion the vehicle body.

In addition, foreign matters such as rainwater and dust are prevented from entering the inside of the stopper main body 2 or the joint between the rod 7 and the damper 10 by an annular projection provided on a part of the expansion and contraction section 4. A dust cover 10 is attached to the portion 6 to protect the cover.

In the case of the conventional bump stopper 1 shown in FIG. 2, in order to obtain required load-bending characteristics, a stopper body including the elastic part 4 is provided with the dust cover mounting part 6 provided on the elastic part 4 as a boundary. On the upper side and the lower side of 2, the elastic deformation is set to be smaller on the lower side than on the upper side.

Therefore, when the expansion and contraction portion 4 is elastically compressed by the contact caused by the upward movement of the damper 10, the dust cover mounting portion 6 is not evenly elastically deformed, and the dust cover 10 is moved as indicated by a virtual line in FIG. Distorted into unnatural shape. If such distortions are repeated over time, the durability may decrease, leading to the worst case such as falling off.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to cover a stopper body composed of an elastic expansion and contraction portion with a dust cover. It is an object of the present invention to provide a bump stopper which can prevent the bump stopper from falling off.

[0008]

A bump stopper according to the present invention is characterized in that a bellows-like cylindrical expansion / contraction part has one end fixed and the other end free, and a damper rod inserted into the inside of the cylinder. On the shaft, the damper moves by receiving external impact force and moves to contact the free end, compresses and deforms the expansion and contraction part, regulates the movement of the damper, absorbs and cushions the external force, and forms an annular projection on the outer periphery of the expansion and contraction part. In the case where a dust cover for preventing foreign matter intrusion is coated and mounted on the provided cover attachment part, the elastic deformation in this elastic part is suppressed and equalized on the outer periphery of the elastic part on the side facing the free end near the cover attachment part The ring-shaped restraining ring is configured to be fitted and held.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a bump stopper according to the present invention will be described in detail with reference to the drawings. The same or similar members as those of the conventional example shown in FIG. 2 are denoted by the same reference numerals, and the description of the overlapping portions will be omitted.

As shown in FIG. 1, the main body 21 of the bump stopper 20 according to the present embodiment is formed into a bellows-like cylinder made of a rubber material such as urethane foam. A rod 7 such as a strud rod shown by a virtual line in the vertical direction in the figure is inserted through the center of the cylinder. The upper end portion of the stopper body 21 fixed to the vehicle body (not shown) via the upper sheet 8 is a rod fitting portion having a fitting hole 23 into which the rod 7 fits with an interference. Is formed with a bellows-like elastic portion 24 which is elastically expandable and contractible in which irregularities are alternately connected.
The lower end, which is the tip of the telescopic part 24, is a free end 25 through which the rod 7 penetrates without interference in a loosely fitted state.

A cover mounting portion 26 is provided on a part of the expansion and contraction portion 24 by an annular projection.
Is attached, the inside of the stopper body 21 and the rod 7
And the damper 9 are covered and protected from infiltration of rainwater and foreign matter.

The cover mounting portion 26 provided on the telescopic portion 24
A constraining ring 30 is attached at a position near either the upper side or the lower side, preferably at a position adjacent to the lower side as shown in the figure, so as to fit on the outer periphery of the elastic portion 24. The constraining ring 30 is made of, for example, 66 nylon containing 30% glass fiber, is formed in an annular shape having a cross-sectional shape as shown in the figure, and is held on the outer periphery of the elastic portion 24 by interference fitting.

The restraining ring 30 includes the cover mounting portion 2
When the actual device is mounted on a vehicle body or the like in a state of being mounted in the vicinity of 6, the following operations are performed. In operation, the damper 9 receives a load and moves upward from below, and its upper flange 9a
Abuts on the free end 25 of the lower end of the elastic portion 24 of the bump stopper 20, the elastic portion 24 is compressed and deformed by receiving a pressing force from the damper 9 from below. At this time, in the vicinity of the dust cover mounting portion 26, a restraining force is exerted by the restraining ring 30 fitted and held therein, so that the elastic portions 24 on the upper side and the lower side of the dust cover mounting portion 26 are evenly elastic. Compression deformation. Following this, the cover attaching portion 26 is also elastically deformed uniformly. As a result, the dust cover mounting portion 26 is uniformly elastically deformed, and as a result, as shown by arrows in the drawing, the dust cover 10 can be normally expanded and contracted with regularity substantially parallel to the movement axis CC of the rod 7. The movement following the elastic compression deformation of the portion 24 is realized.

Due to such normal movement of the dust cover 10, the dust cover 10 does not undergo excessive distortion as shown by the imaginary line 10 in FIG. The problem of falling off has been resolved,
The required durability can be maintained.

The cross-sectional shape of the restraining ring 30 is not limited to a rectangular cross-section as in the illustrated example. For example, by making it correspond to the shape in the vicinity of the cover attaching portion 26 at the portion where the restraining ring 30 is fitted and held, and by forming a cross-sectional shape to be fitted by the uneven portion, for example, a D-ring cross-sectional shape,
The fitting force of the restraining ring 30 is further enhanced, and concerns such as falling off are completely eliminated. Further, the interference in such a concave-convex fitting portion can be suitably set by the materials of both the elastic portion 24 and the restraining ring 30.

[0016]

The bump stopper of the present invention equalizes the elastic deformation of the bump stopper main body including the elastic expansion and contraction portion by fitting the outer periphery of the portion which elastically expands and contracts under a load and attaching the restraining ring. As a result of following the uniform elastic deformation of the bump stopper main body, the dust cover for covering and protecting from foreign matter intrusion can be normally moved, and the durability of the dust cover is reduced due to the movement with excessive distortion of the dust cover, Concerns about dropping out,
The original function of the dust cover can be sufficiently maintained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a bump stopper according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional bump stopper.

[Explanation of symbols]

 7 Damper rod 9 Damper 10 Dust cover 20 Bump stopper 21 Stopper body 23 Rod fitting hole 24 Elastic expansion part 25 Free end of elastic expansion part 26 Cover mounting part 30 Restriction ring

Claims (1)

[Claims] An end portion of a bellows-shaped elastic portion is fixed and the other end portion is a free end, and the damper moves on a rod axis of a damper rod inserted into the cylindrical portion by receiving an external impact. To abut on the free end to compress and deform the expansion / contraction part to regulate the movement of the damper to absorb and buffer external shock force, and to prevent foreign matter from entering the cover mounting part provided in an annular projection on the outer periphery of the expansion / contraction part. In a bump stopper covered with a dust cover, an annular constraining ring that suppresses elastic deformation in the elastic portion and equalizes it around the periphery of the elastic portion on the side facing the free end near the cover mounting portion is fitted and held. A bump stopper characterized in that the bump stopper is configured to perform the following.