JPS61257343A - Bumper spring device - Google Patents

Abstract

PURPOSE:To give a soft characteristic upon low load running and a hard characteristic upon high load running to a bumper spring device, by attaching a rubber absorber to one part of a foamed urethane absorber in the bumper spring device. CONSTITUTION:A bumper spring device 10 is cylindrical, and is composed of a first foamed urethane absorber 30 and a second rubber absorber 32. Further, an insertion hole 34 for a damper rod 14 piercing through the axis of the first absorber 30 has a smaller diameter at its upper end. Further, the second absorber 30 is bonded at its lower end face to the upper end face of the first absorber 30, and the upper end face is made to abut against the lower end face of an upper receiving plate 22.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a bumper bounce used in a suspension device of an automobile or the like and used for contacting a damper body.

[Background Art and Issues to be Solved] In an automobile suspension device, a damper rod protruding from a damper body expands and contracts with the damper body, thereby damping vibrations by fluid resistance within the damper body.

This damper rod has a bumper bound near its tip, which comes into contact with the damper body during large vibrations.

Bumper bounce requires a soft spring constant at low loads, and a hard spring constant at high loads. However, if the bumper bound is made of rubber, it is difficult to obtain soft characteristics under low loads, and if the deflection rate exceeds 50%, the durability will be significantly reduced.

In addition, bumper bounds made of urethane foam have favorable characteristics under low loads due to the flexibility of the material, but it is difficult to obtain hard characteristics under high loads. For this reason, a structure has been adopted in which the bridge is surrounded by a seat or the like around the bumper bound, but it is difficult to obtain a predetermined load characteristic.

In consideration of the above-mentioned fact, the object of the present invention is to obtain a bumper bounce that is soft under low loads and hard under high loads.

[Summary and operation of the invention] The uninvented bumper bound has a structure in which a rubber absorbent part is attached to a part of the foamed urethane absorbent part.

Therefore, under low loads, the urethane foam absorbent part has the soft properties, and under high loads, the rubber absorbent part exhibits the hard properties, and the urethane foam and rubber act as a composite that compensates for the shortcomings of each material. It is supposed to be done.

The foamed urethane absorbing portion and the rubber absorbing portion can each be shaped into a cylinder and attached to the outer periphery of the damper rod.

The rubber absorbent part and the foamed urethane absorbent part can be easily connected by adhering each other or by fitting them into each other.

[Embodiment of the Invention] FIG. 1 shows the vicinity of the upper part of a suspension device to which a bumper bound 10 according to the present embodiment is applied.

In this suspension device, a damper rod 14 is inserted into a cylindrical damper body 12 whose axis is vertical, and a piston (not shown) is attached to the lower end of the damper rod 14. This piston has a through hole, and when the piston moves, the damper body 1
When the liquid sealed in 2 flows through this through hole, vibrations are damped by its viscous resistance. Vibrations from the wheels of the automobile are transmitted to the lower end of the damper body 12.

A small diameter port 16 is coaxially protruded from the upper end of the damper rod 14, and the port 16 is connected to the port 16.
, a spacer 20 and an upper receiving plate 22 are inserted. The outer diameter of the washer 18 is larger than the outer diameter of the damper rod 14.

Note that these washers 18, spacer 920 and port 1
Reference numeral 6 may have a structure in which these are integrally formed and this integral body is fixed to the upper end portion of the damper rod 14 by a suitable fitting structure, welding, or the like.

A port 16 nut 24 is tightened from above the upper receiving plate 22 to fix the upper receiving plate 22 to the damper rod 14. A portion of the upper receiving plate 22 is connected to the vehicle body so that it can support the load from the wheels. Further, this upper receiving plate 22 corresponds to a lower receiving plate 26 fixed to the outer periphery of the damper main body 12, and a compression coil spring 28 is interposed between this lower receiving plate 26 and the lower receiving plate 26. As a result, the damper rod 14 is subjected to an urging force in a direction to be pulled out from the damper main body 12.

The bumper bound 10 has a cylindrical shape and consists of a first absorbent part 30 made of foamed polyurethane and a second absorbent part 32 made of rubber. - For insertion of the damper rod 14 that passes through the axis of the first absorbent part 30. The upper end of the hole is a small diameter hole section 34, and a large diameter hole section 36 is formed below the small diameter hole section 34. Further, below the large-diameter hole 36, a wavy hole portion 38 is provided in which small-diameter holes are formed at predetermined intervals. The lower end surface of the small diameter hole 34 is brought into contact with the upper end surface of a washer 42 whose lower end surface is in contact with the stepped portion 40 interposed between the damper rod 14 and the port 16, whereby the first absorbing portion 30 is prevented from falling off.

The second absorbent section 32 has a cylindrical shape, and its lower end surface is adhered to the upper end surface of the first absorbent section 30, and its upper end surface is in contact with the lower end surface of the upper receiving plate 22. A circular hole 44 having the same diameter as the small-diameter hole portion 34 is bored in the second absorption hole 32 to allow the spacer 20 to pass therethrough.

Note that ring grooves 46 are formed at predetermined intervals on the outer periphery of the first absorbent portion 30 to adjust the compression resistance force of the first absorbent portion 30.

Next, the operation of this embodiment will be explained.

In order to attach the bumper bound 10 to the damper rod 14, the washer 18 is attached to the damper rod 1 in advance.
4 from the top, that is, port 1
Bumper bounce 10 from 6 directions damper rod 14
All you have to do is fit it in.

Thereafter, the upper receiving plate 22 is attached onto the spacer 20 and the nut 24 is tightened to complete the assembly.

The washer 18 and spacer 20 may be attached to the bumper bound 10 in advance, and this subassembly part may be attached to the damper rod 14.

In the suspension device assembled in this manner, vibrations generated as the vehicle travels are attenuated and absorbed by the relative movement in the axial direction between the damper body 12 and the damper rod 14.

When the vibration load is low, the spring constant of the first absorption part 30 is
That is, when the deflection is between 0 and 15 mm, it is 1.0 kg/m.
m, the second absorption part 32 has a deflection rate of 7 at a load of 900 kg.
It is preferable to set it to about 0%.

Therefore, when the vibration load is low, the second absorbing portion 32 hardly deforms and can absorb the load with a low spring constant until the ring groove 46 comes into close contact.

When the load is high, the ring groove 46 is brought into close contact with the ring groove 46 and the air bubbles within the first absorbent portion 30 are compressed. If you want to apply an even higher load, the second absorbent part 32 is volume incompressible, so you can obtain a high reaction force that cannot be obtained if the entire bumper bounce 10 is made of the first absorbent part 30. be able to.

Next, FIG. 3.4 shows a bumper bounce according to a second embodiment of the invention. In this embodiment, the first absorption section 3
A connecting tube 48 is integrally erected from the upper end of the
The second absorbing portion 32 is fitted into the outer periphery of the connecting tube 48 .

Therefore, in this embodiment, there is no need to glue the first absorbent section 30 and the second absorbent section 32 together as in the previous embodiment, and it is only necessary to fit the second absorbent section 32 onto the outer periphery of the connecting tube 48 during assembly. .

In addition to the above, the present invention also provides the first absorption section 30 and the second absorption section 32.
It is also possible to form the other integrally with one of the two when molding the other. In this case, it is preferable to insert the first absorbent part 30 into the mold in advance during foam molding of the second absorbent part 32.

[Effect of the invention] As explained above, in the bumper bounce according to the present invention,
Since the rubber absorbent part is attached to a part of the foamed urethane absorbent part, the load characteristics of both can be effectively utilized, and the excellent effect is that effective characteristics can be obtained from low loads to high loads.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a part of a suspension device to which a first embodiment of the bumper bound according to the present invention is applied, FIG. 2 is an exploded side view of the bumper bound shown in FIG. 1, and FIG. 3 is an exploded side view of the bumper bound according to the present invention. FIG. 4 is an exploded side view of the second embodiment. 10---Bumper bound, 14...Damper rod 14 30...Steel 1 absorption part, 32...-Second absorption part, 48...Connection tube.

Claims (4)

[Claims] (1) A cylindrical bumper bound that is attached to a damper rod and used for contact with the damper body, and is characterized in that a rubber absorbent part is attached to a part of the foamed urethane absorbent part. . (2) The bumper bounce according to claim 1, wherein the foamed urethane absorbing portion and the rubber absorbing portion are each formed into a cylindrical shape and are attached to the outer periphery of a damper rod. (3) The bumper bound according to claim 1 or 2, wherein the rubber absorbent part is bonded to one end of the foamed urethane absorbent part. (4) The bumper bound according to claim 1 or 2, wherein the rubber absorbent part is fitted into a foamed urethane absorbent part.