JPS628666Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention is a suspension for automobiles that has non-linear spring characteristics in the direction perpendicular to the axis and also has good prying characteristics, which improves the steering stability of the vehicle. Regarding Butsuyu (hereinafter referred to as "Butsuyu").

(Prior art) Conventionally, in automobile suspensions, suspension members such as various arms, rods, and links swing in various directions in order to suspend wheels, differentials, etc. on the vehicle body or frame. Bushes are generally incorporated into the pivot joints at both ends of these suspension members for the purpose of damping vibrations and the like.

By the way, as shown in FIG. 5, such a bushing includes inner and outer cylindrical fittings 1 and 2, and a cylindrical intermediate fitting 3 disposed between the inner and outer cylindrical fittings 1 and 2, respectively, concentrically. A structure in which a rubber sleeve 4 is arranged so as to fill the gap between these metal fittings is known, and generally from the viewpoint of handling stability,
It is designed to have a large spring constant in the direction perpendicular to the axis and a small spring constant in the axial direction.

(Problems that the invention aims to solve) However, the bush with this structure is too rigid to withstand prying, and there are still problems with handling stability. cannot be deterred.

The present invention has been devised in view of the above circumstances, and aims to provide a bushing that maintains good steering stability and also has an excellent function of preventing transmission of vibrations and noise to the vehicle body.

(Solution) In the present invention, inner and outer cylindrical fittings and a cylindrical intermediate fitting arranged between the inner and outer cylindrical fittings are arranged concentrically, and a rubber sleeve is arranged between each of these fittings. In the case of the bush, the axial cross-sectional shape of the rubber sleeve disposed between the intermediate metal fitting and the outer cylindrical metal fitting is such that the side in contact with the inner surface of the outer cylindrical metal fitting is the upper base, the side in contact with the outer surface of the intermediate metal fitting is the lower bottom, and the side in contact with the outer surface of the intermediate metal fitting is the lower bottom. The outer cylinder fitting has a substantially trapezoidal shape with a height equal to the distance between the outer cylinder fitting and the outer cylinder fitting, and an annular protrusion that protrudes radially inward is provided at an axially intermediate position of the outer cylinder fitting, and the annular protrusion is inserted into the rubber sleeve. The gist is the content that is structured in a detailed manner.

(Example) Next, the present invention will be explained in detail based on examples.

Figure 1 shows the suspension bushing 10 of this invention.
This is an example of 0, and the inner and outer cylinder fittings 10, 20
and a cylindrical intermediate fitting 30 disposed between the inner and outer cylindrical fittings 10 and 20 are arranged concentrically, and a full inner rubber sleeve 40 is disposed between the inner cylindrical fitting 10 and the intermediate fitting 30. An outer rubber sleeve 50 is disposed between the outer cylindrical metal fitting 20 and the intermediate metal fitting 30. The outer layer rubber sleeve 50 has an axial cross-sectional shape such that the side in contact with the inner surface of the outer tube fitting 20 is the "upper bottom", the side in contact with the outer surface of the intermediate fitting 30 is the "lower bottom", and the edge between the intermediate fitting 30 and the outer tube fitting 20 is the "upper bottom". It is configured in a roughly trapezoidal shape with distance as "height". Furthermore, the outer cylinder fitting 20 is provided with an annular protrusion 70 that protrudes radially inward at an intermediate position in the axial direction, and the annular protrusion 70 bites into the outer rubber sleeve 50. The annular protrusion 70 provided on the outer cylinder fitting 20 is
The outer cylindrical metal fitting 20 may be formed in advance by mechanical processing such as drawing, or it may be formed in the same manner after the bushing is formed.

The inner and outer rubber sleeves 40 and 50 are fixed to each fitting surface by vulcanization adhesive, but it is also possible to arrange only the outer rubber sleeve 50 and the inner surface of the outer cylindrical fitting 20 without adhesive. In either case, the diameter is reduced by squeezing the outer cylindrical metal fitting 20 to give preliminary compression to each rubber sleeve.

In addition, in the axial cross section (approximately trapezoidal shape) of the outer rubber sleeve 50, the ratio A/B of the axial length A of the portion in contact with the outer cylinder fitting 20 and the axial length B of the portion in contact with the intermediate fitting 30. is preferably set in the range of 1/5 to 1/2 from the viewpoint of prying characteristics.

Next, the action of the bush will be explained.

Regarding the spring characteristics in the direction perpendicular to the axis, the above-mentioned bush exhibits a soft spring (spring constant K ₁ ) mainly due to the action of the outer rubber sleeve 50 in the low load region, and the inner rubber sleeve 40 acts as a stopper member in the high load region. It exhibits a hard spring (spring constant K ₂ ) and exhibits nonlinear characteristics as shown in FIG. 3 that increase the K ₂ /K ₁ ratio.

On the other hand, the prying characteristics of the bushing are such that the outer rubber sleeve 50 has a substantially trapezoidal cross-sectional shape in the axial direction, and a gap is provided between the intermediate metal fitting 30 and the outer cylindrical metal fitting 20, as shown in Fig. 4. As shown in , the prying moment against prying (prying load P) is reduced, and good prying characteristics are exhibited.

In addition, since the bush is constructed by providing an annular projection 70 on the outer cylindrical metal fitting 20 and biting it into the outer rubber sleeve 50, the shaft of the outer rubber sleeve 50 is designed to improve prying characteristics. As a result of making the directional cross-sectional shape substantially trapezoidal, the reduction in the axial holding strength of the outer tubular fitting 20 due to a reduction in the contact area between the outer tubular fitting 20 and the outer rubber sleeve 50 is suppressed, and a predetermined holding strength is maintained. do. Such effects are remarkable when the outer cylinder metal fitting 20 and the outer rubber sleeve 50 are not bonded to each other.

Note that the shape of the annular protrusion in the present invention can be any shape other than the above-mentioned embodiments, and can also be shaped as shown in FIG. 2, for example.

(Effects of the invention) As explained in detail above, the bush of the invention exhibits non-linear spring characteristics in the direction perpendicular to the axis and also exhibits good prying characteristics, thereby maintaining good steering stability of the vehicle and maintaining the vehicle body. It also has an excellent ability to prevent vibrations and noise from being transmitted to the sides.

[Brief explanation of the drawing]

Fig. 1 is an axial sectional view showing one embodiment of the bush of the present invention, Fig. 2 is a sectional view equivalent to Fig. 1 showing another embodiment of the invention, and Fig. 3 shows the spring characteristics in the direction perpendicular to the axis. FIG. 4 is a graph showing the prying characteristics, and FIG. 5 is a sectional view corresponding to FIG. 1 showing a conventional bushing. 10...Inner cylinder metal fitting, 20...Outer cylinder metal fitting, 30...
...Intermediate metal fitting, 40...Inner layer rubber sleeve, 50...
... Outer layer rubber sleeve, 70 ... Annular protrusion, 100
...Buzz.

Claims (1)

[Scope of Claim for Utility Model Registration] Inner and outer cylindrical fittings and cylindrical intermediate fittings arranged between the inner and outer cylindrical fittings are arranged concentrically, and a rubber sleeve is arranged between these fittings. In the suspension bushing, the axial cross-sectional shape of the rubber sleeve disposed between the intermediate metal fitting and the outer cylinder metal fitting is such that the side in contact with the inner surface of the outer cylinder metal fitting is the upper bottom, and the side in contact with the outer surface of the intermediate metal fitting is the lower bottom. , is formed into a substantially trapezoidal shape with the height being the distance between the intermediate metal fitting and the outer cylinder metal fitting, and an annular protrusion that protrudes radially inward is provided at an axially intermediate position of the outer cylinder metal fitting, and the annular protrusion is made of rubber. A suspension bushing characterized by being inserted into the sleeve.