JPS6215534Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dust cover for a universal joint used in, for example, a steering link mechanism of an automobile, which is capable of reliably sealing a joint portion of a swinging arm from the outside, especially during swinging.

In automobile steering link mechanisms, various arms are connected through universal joints, especially arm studs, so that the arm axis can be twisted or the other arm can swing along the axis of the other arm. There is. In these devices, a dust cover is generally used to retain lubricating oil in the joint or to prevent dust from entering the joint from the outside.

As a dust cover for such a universal joint, one shown in FIG. 1, for example, is conventionally known. That is, the dust cover 1 is made of a flexible material such as rubber and is made of a cylindrical base 2 and a bellows-shaped seal portion 3 that communicates with and protrudes from the peripheral wall 2A of the cylindrical base 2. It is set up. The cylindrical base 2 of this dust cover 1 is attached to one arm to be connected, for example, the joint 5 of the drag link 4, and is tightened and fixed with a set ring 6, and the bellows-shaped seal 3 is attached to the drag link 4. The arm stud 8 of the other arm to be connected, such as the Pitman arm 7, which is rotatably and swingably inserted into the joint portion 5, is covered. The bellows-shaped seal portion 3 of the dust cover 1 allows the arm stud 8 to be covered to rotate in the circumferential direction A in a sliding state, and the arm stud 8 is in sliding contact with the drag link 4.
It is desirable to oscillate following the rocking in the direction B along the axis of the cylinder, and to ensure sealing performance in both cases. Therefore, in general, the arm stud 8 is tapered so that the diameter gradually increases in the direction rising from the drag link 4, and elasticity is imparted to the bellows-shaped seal portion 3 along the direction of extension, that is, the direction of the large diameter of the arm stud 8. is always brought into pressure contact with the large diameter side of the arm stud 8, so that no gap will occur no matter what type of joint operation occurs.

However, according to such a conventional dust cover 1, since the bellows-shaped peripheral wall portion of the seal portion 3 has a substantially uniform thickness in the circumferential direction, the cylindrical base portion 2 and the seal portion 3 Among the continuous parts, the side surface portion perpendicular to the axis of the cylindrical base 2 is easily deformed by a deforming force from the outside. That is, the arm stud 8 is connected to the drag link 4.
When the arm stud 8 is tilted in either direction B along the axis of the arm stud 8, the compressive force in the tilt direction causes the side surface portion to be greatly deformed, thereby causing the entire seal portion 3 to contract, which causes the arm stud 8 to oscillate. As a result, a gap is created between the seal portion 3 and the opposite side of the arm stud 8 in the direction of inclination.
The sealing properties tended to be incomplete. Therefore, over a long period of time, there was a risk that dust would enter the joint through the gap or that lubricating oil would leak, impairing the function of the universal joint.

The present invention was developed in view of the above circumstances, and the bellows-shaped seal portion fully follows the swinging motion of the arm stud to prevent the occurrence of a gap in the opposite direction of inclination. obtain. In other words, the sealing performance can be maintained reliably regardless of the swinging of the arm stud.
It is an object of the present invention to provide a dust cover for a universal joint that can greatly contribute to maintaining the function of the joint.

A feature of the present invention that achieves such an object is that, in a part where a cylindrical base and a bellows-shaped seal part are connected, a side surface that is orthogonal to the axis of the cylindrical base is provided with an axial direction of the bellows-shaped seal part. For example, even if the seal part is subjected to compressive action due to swinging of the arm stud on one side along the axis of the cylindrical base, the reinforcing part increases the steel strength along the axis of the cylindrical base. This is intended to prevent the generation of gaps by preventing unnecessary compression from being applied due to the effect of rigidity.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 4.

This example relates to a dust cover for a universal joint used in an automobile steering link mechanism, and the mounting configuration is the same as that shown in Fig. 1, so the same figure and the reference numerals attached thereto are used. I will refer to it as is and explain it.

A dust cover 1 is provided in which a cylindrical base 2 and a bellows-shaped seal portion 3 that communicates with and protrudes from the peripheral wall 2A of the cylindrical base 2 are integrally formed of a flexible material such as rubber. There is. A bellows-shaped seal is attached to a side surface portion 9A of the connecting portion between the cylindrical base 2 and the bellows-shaped seal portion 3 of the dust cover 1 (hereinafter referred to as the neck portion 9) along a direction perpendicular to the axis C of the cylindrical base 2. A reinforcing portion 10 that increases the rigidity of the seal portion 3 in the axial direction D is integrally formed. In this reinforcing part 10, the neck part 9 perpendicular to the axis C of the cylindrical base part 2 is formed into a fold wall having an uneven cross-sectional shape, and the fold extends along the axial direction D of the seal part 3. That is, the stiffness of the seal portion 3 in the axial direction D is increased by the folded wall. The number of folds and the pitch of the folds as the reinforcing portion 10 can be set as appropriate depending on the elasticity or dimensions of the dust cover 1.

With such a configuration, the stiffness of the seal portion 3 along the axis D is improved by the reinforcing portion 10 made of the folded wall formed on the neck portion 9, so that the arm stud 8 covered with the seal portion 3 is attached to the cylindrical base. Even if the drag link 4 on which the drag link 2 is attached is tilted to one side by swinging in the direction along the axis, the bellows-shaped seal portion 3 contracts only in a part on the side in the direction of inclination. On the side, the seal part 3 is the reinforcement part 1
It is held uncontracted by 0. That is, it is possible to prevent the seal portion 3 as a whole from shifting toward the smaller diameter side of the arm stud 8, and it is possible to prevent an unnecessary gap from being created by following the swinging motion of the arm stud 8 in a good swinging state. Therefore, the seal portion 3 can secure sufficient sealing material, and the joint portion 5
It is possible to overcome drawbacks such as dust intrusion into the universal joint and leakage of lubricating oil from the joint part 5, and maintain the function of the universal joint for a long period of time.

In the embodiment described above, the reinforcing part 10 is constructed by making the neck part 9 itself a pleated wall, but the reinforcing part 10 may have the function of increasing the rigidity of the bellows-shaped seal part 3 in the axial direction. Therefore, various embodiments other than those described above may be applied as specific implementation configurations.

That is, FIGS. 5 to 7 show another embodiment of the present invention, in which the reinforcing part 10 is formed by a thick line 1 rising in the axial direction D of the seal part 3 formed in a part of the neck part 9.
1. Such a line 1
Even if the reinforcing portion 10 is made of 1, the stiffness of the neck portion 9 in the axial direction D of the seal portion 3 can be increased, so that the same effects as in the previous embodiment can be achieved. It goes without saying that the thickness, number, spacing, etc. of the striations 11 can be varied as necessary.

Further, FIGS. 8 to 10 show still another embodiment of the present invention, in which the reinforcing portion 10 is formed by forming the neck portion 9 into a thick wall 12 in the form of a thick plate having a predetermined area. It is composed of This thick wall 12 has, for example, a substantially triangular shape that gradually becomes wider toward the tip side of the seal portion 3, and gradually becomes thicker from the center along the axis of the seal portion 3 toward both sides. This is what I did. Even with such a configuration, since the neck portion 9 has a thick wall in one direction, the rigidity of the bellows-shaped seal portion 3 in the axial direction D is improved, and the same effects as in the embodiment described above can be achieved. In addition, this thick wall 1
Of course, the thickness, shape, etc. of 2 can be varied as necessary.

In addition to the above-mentioned embodiments, the present invention can be applied to dust covers of various types of joints such as tie rod joints.

As described in detail in the above embodiments, the present invention forms a reinforcing part in the continuous part of the cylindrical base and the bellows-shaped seal part to increase the rigidity along the axial direction of the seal part. When the arm stud swings in the direction along the axis of the cylindrical base, there is no unnecessary contraction and the generation of gaps can be prevented. This prevents dust from entering the joint, thereby improving the maintenance of the joint. This can greatly contribute to the

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing a state in which a conventional dust cover is attached, Figs. 2 to 4 show an embodiment of the present invention, Fig. 2 is a front view, and Fig. - Line sectional view, Figure 4 is a plan view of Figure 2, Figures 5 to 7 show other embodiments of the present invention, Figure 5 is a front view, and Figure 6 is the same as Figure 5. FIG. 7 is a plan view of FIG. 5, and FIGS. 8 to 10 show still other embodiments of the present invention.
The figure is a front view, Figure 9 is a sectional view taken along the - line in Figure 8,
FIG. 10 is a plan view of FIG. 8. 1... Dust cover, 2... Cylindrical base, 3...
Seal part, 4... One arm (drag link), 5... Joint part, 7... Other arm (Pittman arm), 8... Arm stud, 9...
A connecting part (neck part) between the cylindrical base and the seal part, 10,
11, 12...Reinforcement part.

Claims (1)

[Claims for Utility Model Registration] (1) A cylindrical base and a bellows-shaped seal portion that communicates with and protrudes from the peripheral wall of the cylindrical base are integrally molded of a flexible material, and the cylindrical The bellows-shaped seal part is attached to the joint part of one arm to be connected, and the bellows-shaped seal part is swingably inserted into the joint part of the one arm, and the arm stud of the other arm to be connected is covered. The dust cover of the universal joint is configured such that the bellows-shaped seal portion is provided on a side surface perpendicular to the axis of the cylindrical base portion of a continuous portion between the cylindrical base portion and the bellows-shaped seal portion. A dust cover for a universal joint, characterized by integrally forming a reinforcing part to increase rigidity along the axial direction. (2) The reinforcing part has a fold wall with an uneven cross section at the connecting part between the cylindrical base and the bellows-shaped seal part, and the fold extends along the axial direction of the seal part. A dust cover for a universal joint according to claim 1 of the patented utility model. (3) The reinforcing portion is constructed by a part of the connecting portion between the cylindrical base and the bellows-shaped seal portion having a thick wall and a line rising in the axial direction of the seal portion. A dust cover for a universal joint according to claim 1 of the utility model registration claim. (4) Registration of a utility model characterized in that the reinforcing part is constructed by a thick plate-like wall having a predetermined area at the connecting part between the cylindrical base and the bellows-shaped seal part. A dust cover for a universal joint according to claim 1.