JPH0723820U - Ball joint dust cover - Google Patents

Abstract

(57) [Abstract] [Purpose] For ball joints with large swing angles,
Establish a bell-type and fitting-type compact dust cover to reduce the number of parts, simplify the assembly process, and reduce costs. A dust cover 20 is a bell type and a fitting type to the socket 2, a central film portion 21 is formed in a bell shape, and one end opening portion 22 can be fitted to the outer periphery of the fastening portion 3. An annular metal fitting 24 is insert-molded, and a seal portion 25 slidably contacting the plate 10 is provided on the inner periphery of the other end opening 23.
Are formed. On the inner peripheral surface of the central membrane portion 21 near the one-end opening portion 22, by gradually changing the film thickness of the central membrane portion 21, a projecting protrusion 26 that can abut the abutted portion 4 of the socket 2. Are formed. By contacting the contacted portion 4, the projecting projection 26 projects the central film portion 21 so as to surely inflate the central film portion 21 toward the outer peripheral side.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dust cover for a ball joint used for a suspension mechanism, a steering mechanism, etc. of an automobile.

[0002]

[Prior art]

 As shown in FIGS. 3 to 5, the ball joint 30 of this type prevents dust from entering between the ball seat 32 disposed in the socket 31 and the ball head 34 of the stud 33. Therefore, the dust covers 40 and 50 made of soft synthetic resin or rubber are attached.

First, the dust cover 40 shown in FIG. 3 is a bell type and is a fitting type to the socket 31, and the central film part 41 has a large total height by disposing a mold (not shown) inside. It is formed in a bell shape, an annular metal fitting 44 that can be fitted to the outer periphery of the fastening portion 35 of the socket 31 is insert-molded in the one end opening 42, and the outer periphery of the stud 33 is formed in the inner periphery of the other end opening 43. A seal portion 45 that is in sliding contact with the plate 36 is formed. To attach the dust cover 40 to the ball joint 30, the one end opening 42 of the dust cover 40 is fitted into the socket 31 as shown in FIG. 3, and then the dust cover 40 is attached as shown in FIG. The knuckle 47 compresses the stud 33 in the axial direction, and the other end opening 43 is fitted onto the plate 36. By this compression, the overall height of the dust cover 40 is reduced, and the bell-shaped central film portion 41 swells in a meandering manner and expands in diameter.

Next, the dust cover 50 shown in FIG. 5 is a bellows type and a set ring attachment type to the socket 31, in which the central film portion 51 is formed in a bellows shape in advance, and the one end opening portion 52 is a separate component. A mounting groove 55 for mounting the set ring 54 is formed, and a seal portion 56 similar to the seal portion 45 is formed on the inner periphery of the other end opening portion 53. The set ring 54 is mounted in the mounting groove 55 after expanding its inner diameter with a tool, and after mounting, elastically contracts in diameter so that the one-end opening 52 is tightened to the outer periphery of the fastening portion 35. .

[0005]

[Problems to be solved by the device]

 The former bell-bell-type and fitting-type dust cover 40 has the advantage that it can be fastened to the socket 31 by a simple method in which the annular metal fitting 44 is pushed into the outer periphery of the fastening portion 35 to be fitted. There was a problem. That is, as indicated by the chain double-dashed line in FIG. 4, when the swing angle θ of the stud 33 with respect to the socket 31 is large, the film length of the central film portion 41 is set to follow the deformation of the dust cover 40. Need to be bigger. Therefore, as described above, the dust cover 40 was formed into a bell shape having a large overall height, and then largely compressed. However, when the dust cover 40 is compressed to a large extent in this manner, when the swing angle θ of the stud 33 is large, a part of the central film portion 41 is deeply folded toward the inner peripheral side as shown by the chain double-dashed line, There was a concern that the socket 31 and the stud 33 would be caught between them. Therefore, in a ball joint having a large swing angle θ (for example, 24 degrees or more), such a bell-shaped and fitting-type compact dust cover 40 cannot be realized.

On the other hand, in the latter bellows type and set ring attachment type dust cover 50, since the central membrane portion 51 is formed in advance in a bellows shape which is advantageous for securing the membrane length, In addition, there is no need to significantly compress when assembling to a car. For this reason, there is an advantage that there is no concern about the above-mentioned bite, and it is also established in a ball joint having a large swing angle. However, since the set ring 54 is a separate part and its mounting is troublesome, the number of parts is increased, the assembly process is complicated, and the cost is increased.

An object of the present invention is to solve the above problems and to provide a bell-shaped and fitting-type compact dust cover in a ball joint with a large swing angle, thereby reducing the number of parts, An object of the present invention is to provide a new dust cover for a ball joint that can simplify the assembly process and reduce the cost.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, in the present invention, the central film portion is formed in a bell shape, the one end opening is provided with an annular metal fitting that can be fitted to the outer circumference of the socket, and the other end opening is provided to the outer circumference of the stud. In the dust cover of the ball joint that is fitted to the outside, a means for providing a protrusion for contacting the outer surface of the socket is provided on the inner peripheral surface of the central film portion near the one end opening.

[0009]

[Action]

 When the dust cover of the present invention is attached to the ball joint, one end opening is fitted to the outer circumference of the socket by an annular metal fitting, the other end opening is fitted to the outer circumference of the stud, and the bell-shaped central film part is expanded and expanded. To do. At this time, the protrusion for protrusion provided on the inner peripheral surface near the one end opening of the central membrane portion abuts on the outer surface of the socket, and thereby protrudes so that the central membrane portion surely bulges toward the outer peripheral side. Even when the stud swings greatly, the projecting portion for projecting stretches the central membrane portion so as to bulge the outer peripheral side, so that the central membrane portion is folded toward the inner peripheral side as in the conventional case and is caught. This is true even for ball joints with a large swing angle.

[0010]

【Example】

 An embodiment of a dust cover embodying the present invention will be described below with reference to FIGS. 1 and 2. First, the ball joint 1 to which the dust cover is attached will be briefly described. Reference numeral 2 denotes a socket, on the outer periphery of which a fastening portion 3 of the dust cover is notched with an L-shaped cross section, and an upper edge of the fastening portion 3 is composed of a corner portion and a stepped surface that follows it. The contacted portion 4 is formed. Reference numeral 5 denotes an accommodation chamber that is recessed inward from the upper surface of the socket 2, and 6 denotes a ball seat made of synthetic resin disposed in the accommodation chamber 5. Reference numeral 7 denotes a stud, which comprises a shaft portion 8 and a ball head 9 which is inserted into the accommodation chamber 5 in a non-removable manner and is in sliding contact with the ball seat 6. Reference numeral 10 is a flange-shaped plate fixed to the outer periphery of the shaft portion 8 of the stud 7.

Now, the dust cover 20 of the present embodiment is a bell type and is a fitting type for the socket 2. As shown in FIG. 2, the central film portion 21 is formed in a bell shape and has an opening at one end. An annular metal fitting 24 that can be fitted to the outer periphery of the fastening portion 3 is insert-molded in the second portion 22, and a seal portion 25 that slidably contacts the plate 10 is formed on the inner periphery of the other end opening portion 23. The inner peripheral edge of the annular metal fitting 24 before fitting is formed so that a thin metal plate is bent obliquely upward, and the inner diameter of the annular metal fitting 24 is set to be slightly smaller than the outer diameter of the fastening portion 3 shown in FIG. Therefore, after fitting, the inner peripheral edge of the annular metal fitting 24 is further warped to tighten the outer circumference of the fastening portion 3.

On the inner peripheral surface of the central membrane portion 21 near the one-end opening portion 22, for thrusting which can abut the abutted portion 4 of the socket 2 by gradually changing the film thickness of the central membrane portion 21. The protrusion 26 is formed. The projecting protrusion 26 of this embodiment is a continuous annular member.

In order to mount the dust cover 20 on the ball joint 1, the one end opening 22 of the dust cover 20 is fitted into the socket 2 by the annular metal fitting 24, and then the dust cover 20 is knuckled (not shown). The stud 7 is compressed in the axial direction, and the other end opening 23 is fitted onto the plate 10 as shown in FIG. By this compression, the overall height of the dust cover 20 is reduced, and the bell-shaped central film portion 21 swells and expands in diameter. At this time, the projecting projections 26 of the central film portion 21 abut on the contacted portions 4 of the socket 2 to thereby project the central film portion 21 to surely inflate toward the outer peripheral side. In particular, in this embodiment, since the projecting portion for protrusion 26 is formed by gradually changing the film thickness of the central film portion 21, the above-mentioned protrusion action is strong. Then, as shown by the chain double-dashed line in FIG. 1, even when the stud 7 swings largely, the protrusion 26 for protrusion protrudes the central membrane portion 21 toward the outer peripheral side. In addition, there is no concern that the central membrane portion 21 is folded toward the inner peripheral side and is bitten, and it is also established in the ball joint 1 having a large swing angle θ (for example, 24 degrees or more).

The present invention is not limited to the configuration of the above-described embodiment, and may be embodied by being arbitrarily modified within the scope not departing from the spirit of the invention, for example, as follows. (1) To form the protrusions 26 for tensioning into a plurality of protrusions that are not continuous with each other. (2) Enlarge the protrusion 26 for tensioning so as to contact the outer peripheral surface of the upper end of the socket.

[0015]

[Effect of device]

 Since the present invention is configured as described above, it is possible to establish a bell-type and fitting-type compact dust cover in a ball joint with a large swing angle, thereby reducing the number of parts and assembling process. It has an excellent effect that it is possible to achieve simplification and cost reduction.

[Brief description of drawings]

FIG. 1 is a sectional view showing a ball joint equipped with a dust cover according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of the dust cover after molding.

FIG. 3 is a cross-sectional view of a ball joint in the process of mounting a conventional dust cover.

FIG. 4 is a cross-sectional view of a ball joint equipped with the dust cover.

FIG. 5 is a cross-sectional view of a ball joint equipped with another conventional dust cover.

[Explanation of symbols]

1 Ball Joint 2 Socket 3 Fastening Part 4 Contacted Part 7 Stud 8 Shaft Part 10 Plate 20 Dust Cover 21 Central Membrane Part 22 One End Opening 23 Other End Opening 24 Annular Metal Fitting 25 Sealing Part 26 Protrusion Projecting Part

Claims (1)

[Scope of utility model registration request] 1. A dust cover for a ball joint in which a central film portion is formed in a bell shape, an annular metal fitting that can be fitted to the outer circumference of a socket is provided at one end opening, and the other end opening is externally fitted to the outer circumference of a stud. The dust cover for a ball joint according to claim 1, wherein a protrusion for protrusion is provided on an inner peripheral surface of the central film portion near the one end opening, the protrusion being capable of contacting an outer surface of the socket.