JPH045781Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD The present invention relates to a strut trunk assembly for an automobile wheel suspension.

PRIOR ART FIG. 1 shows a conventional strut trunk assembly. A cushion 3 is interposed between a lower arm 1 as a vehicle body member and a strut bar 2 extending in the longitudinal direction of the vehicle.
The cushion 3 is attached between an inner tube 4 through which the strut bar 2 passes and an outer tube 5 attached to the lower arm 1. For the sake of improvement, the lower arm 1 is formed so that it can be inserted from both sides.

Further, a retainer 6 is attached to the strut bar 2, which clamps both ends of the inner tube 4 and faces both end surfaces of the cushion 3 at a predetermined distance, and is fixed by tightening with nuts 7. .

However, in the conventional device, since the inner cylinders 4 are already in contact with each other as shown in FIG. 2 before the retainer 6 is attached, even when the retainer 6 is tightened, no stress is applied to the cushion 3 and it does not deform.

In the conventional example, vibrations in the axial direction of the strut bar 2 due to road resistance during driving are alleviated by the spring characteristics of the cushion 3, so that the vibrations are not directly transmitted to the vehicle body.

However, at this time, a large tensile force is applied to the cushion 3, and the durability of the cushion 3 is reduced due to the nature of rubber, which is weak against tension. Furthermore, if the rubber hardness is increased, the durability of the cushion 3 will be improved, but the vibration absorption properties will be reduced.

Purpose This invention was made to solve the above-mentioned problems, and uses a pre-compression method that is applied to the cushion in advance to reduce the axial tensile stress that is generated in the cushion due to vibrations during running. It is an object of the present invention to provide a strut bending assembly which can improve the durability of the cushion by reducing the amount of stress caused by the struts.

Structure This invention consists of a cushion made of an elastic member such as rubber, which is fixed between an outer cylinder having a flange and an inner cylinder, and having an annular groove provided on the outer end surface.
When the connecting members are inserted from both sides of the lower arm, the thickness of the cushion between the inner cylinder and the outer end is approximately 20 mm between the inner end surfaces of the inner cylinders. % or more is formed.When the nut is tightened to the strut bar, the inner end surfaces of both inner cylinders come into contact, and the cushion is compressively deformed in the axial direction, applying precompression. , a retainer is brought into contact with the outer end surface of each inner cylinder, and a gap is provided between the retainer and the cushion.

Example Examples 3 to 6 below are examples that embody this idea.
Referring to the drawings, the end of the strut bar 14 is connected to the lower arm 15 via a strut bark assembly 10.

As shown in FIG. 3, the strut bark assembly 10 has two connecting members 11 inserted from both sides of the lower arm 15.
It consists of the following cushion 16, inner cylinder 17 and outer cylinder 18. The cushion 16 is made of an elastic member such as rubber, and is formed by vulcanization bonding or the like between inner cylinders 17 made of metal on both sides into which the strut bar 14 is fitted, and an outer cylinder 18 with a flange 18a that abuts the lower arm 15. Fixed. Same cushion 1
6 is formed into a cylindrical shape between the outer and outer cylinders 17 and 18 (the thickness of the portion between the inner and outer cylinders of the same cushion is t).
) The outside of the flange 18a is enlarged in diameter over the entire circumference.

Further, the cushion 16 is assembled so that compressive stress remains when the cushion 16 is in a neutral state with no external force in the axial direction. That is, the cushion 16 has an inner peripheral portion 16a on the inner end surface as shown in FIG. 4 before installation, and an inner cylinder 17 after installation.
Since the inner end surfaces of the
As shown in the figure, since this inner peripheral portion 16a protrudes in a gentle curve, the compressive stress acts on the cushion 16 due to the compressive deformation during installation, and the cushion 16 is always pre-compressed. There is.

Further, an annular groove 20 is formed on the outer end surface of the cushion 16.

Two retainers 21 are provided on the outer end surface of each inner cylinder 17.
However, one side is locked to the stepped portion of the strut bar 14, and the other side is tightened and fixed with a nut 22, and as a result of this tightening and fixing, the inner end surfaces of the inner cylinder 17, which were facing each other with a length gap 19 in the above, are fixed. press against each other. Further, a gap is provided between each retainer 21 and the outer end surface of the cushion 16, so that the cushion 16 comes into contact with the retainer 21 only when it is largely displaced in the axial direction.

Next, the installation procedure of the strut bark cushion assembly constructed in this way will be explained. The cushion 16 is vulcanized and bonded between the inner cylinder 17 and the outer cylinder 18, and the two connecting members 11 are attached. form.

Thereafter, an assembly is manufactured in which the outer cylinder 18 is reduced by about 2% in the inner longitudinal direction. Subsequently, these are inserted from the front and rear of the lower arm 15 as shown in FIG. 4, and the flange portion 18a is brought into contact with the lower arm 15. At this time, a long gap 19 is formed between both end surfaces of both inner cylinders 17 as described above. Thereafter, the two retainers 21 are placed against the outer end surface of the inner cylinder 17, the strut bar 14 is passed through the inner cylinder 17, and the nut 22 is
When the two inner cylinders 17 are brought into pressure contact with each other by tightening them, the strut bending assembly 10 is completed.

In this embodiment, the length of the interval is approximately 70% of the wall thickness of the cylindrical portion of the cushion.

As shown in FIG. 5, when the strut bark assembly 10 installed as described above is subjected to axial vibration during running, the inner cylinder 17 and the outer cylinder 18 move relative to each other in the axial direction. Cushion 16
An external force is applied in the direction of pulling in the axial direction.

However, as described above, the cushion 16 has been compressively deformed in advance and has residual compressive stress in the axial direction, so the external force either eliminates this compressive stress or adds some additional tensile stress. Therefore, compared to the conventional cushion 1
6 is reduced, and the durability of the cushion, which is made of an elastic material such as rubber that is strong against compression but weak against tension, is significantly improved. Furthermore, since vibrations are absorbed and alleviated by the cushion 16, less transmission to the vehicle body occurs.

Furthermore, when a large force is applied to the strut bar 14 and the deformation of the cushion exceeds a predetermined value, the cushion 16 is abutted and supported by the retainer 21, so that steering stability is achieved.

Further, when the strut bar 14 is twisted so as to swing, the annular groove 20 allows the cushion 16 to
The stress generated in the process is reduced.

Note that the present invention is not limited to the above-mentioned embodiments, and can be embodied as follows, for example.

(1) According to experiments, the interval length is the thickness of the cylindrical part of the cushion, as shown by the broken line A in Figure 6, which represents the interval length/thickness t of the cylindrical part and durability.
Since the durability of the cushion is significantly improved when the content is 20% or more, it is possible to operate within this range.

Effects As described in detail above, this invention has already applied compressive deformation to the cushion when it is attached to the strut bar, so the tensile stress generated by the cushion due to axial vibration during running is reduced. Deformation exceeding a predetermined value is supported by the retainer, and if the strut bar is twisted so as to swing, this is reduced by the annular groove.
Therefore, it has the excellent effect of significantly improving the durability of the rubber, and is an excellent invention for industrial use.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing the conventional strut bending after installation, Fig. 2 is a longitudinal sectional view showing the conventional strut bending before installation, and Figs. 3 to 5 show the present invention. A concrete example is shown. Fig. 3 is a vertical cross-sectional view showing the strut bending after installation, Fig. 4 is a longitudinal cross-sectional view showing the strut bending before installation, and Fig. 5 is the strut bending when it is deformed. 6 is a diagram showing the relationship between the length of the gap/thickness t of the cylindrical portion and durability. 10...Strut bending assembly,
11... Connection member, 14... Strut bar, 1
5...Lower arm, 16...Cushion, 17...
...Inner cylinder, 18...Outer cylinder, 19...Gap, 21...
Retainer, 22...Natsuto.

Claims (1)

[Scope of utility model registration request] An outer cylinder 18 having a flange 18a and an inner cylinder 17
The cushion 16 is made of an elastic member such as rubber and has an annular groove 20 on its outer end surface. In the state where the inner cylinder 17 is just inserted, the inner cylinder 17
A gap 19 having a length of 20% or more of the wall thickness of the cushion 16 is formed between the outer cylinder 18 and the inner cylinder 17. The end surfaces abut, and the cushion 16 is compressively deformed in the axial direction to apply precompression.A retainer 21 is abutted to the outer end surface of each inner cylinder 17, and the space between the retainer 21 and the cushion 16 is An assembly of a strut-bark transmission, characterized in that a gap is provided in the .