JPH0640439U - Ball joint dust cover - Google Patents

Abstract

(57) [Summary] [Purpose] In the dust cover of the ball joint,
While adapting to ball joints with large swing angles, the number of parts is reduced, the assembly process is simplified, and the cost is reduced. A central film portion 21 of the dust cover 20 is formed in a bellows shape in advance, an annular metal fitting 24 that can be fitted to the outer periphery of the fastening portion 4 of the ball joint 1 is integrally formed in the opening 22 at one end, and the other end is formed. A seal portion 25 that is in sliding contact with the plate 10 is formed on the inner periphery of the opening portion 23. Since the inner diameter of the annular metal member 24 is set to be larger than the maximum inner diameter of the central film portion 21, it can be released from the mold disposed inside. The dust cover 20 is pressed downward by the knuckle 12, and the other end opening 23
Is fitted onto the plate 10. Even if the swing angle of the stud 7 is large, a part of the central film portion 21 does not contact the socket 2 and the stud 7.
There is no worry of being bitten by.

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. 4 to 6, the ball joint 30 of this kind 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. 4 is of a type that fits into the socket 31, and the central film portion 41 is formed into a bell shape with a mold (not shown) disposed inside and has an opening at one end. An annular metal fitting 44 that can be fitted to the outer periphery of the fastening portion 35 of the socket 31 is integrally molded in the portion 42, and a seal portion 45 that slidably contacts the plate 36 on the outer periphery of the stud 33 is formed on the inner periphery of the other end opening 43. Are formed. Since the inner diameter of the annular metal fitting 44 is set larger than the outer diameter of the mold, the annular metal fitting 44 can be easily removed from the mold after molding. Then, as shown in FIG. 4, the one end opening 42 of the dust cover 40 is fitted into the socket 31 to complete the assembly of the ball joint 30. At this time, the central film portion 41 of the dust cover 40 remains in the bell shape at the time of molding. Next, when assembling this ball joint 30 to an automobile, as shown in FIG. 5, the dust cover 40 is compressed in the axial direction of the stud 33 by the knuckle 47, and the other end opening 43 is externally fitted to the plate 36. Therefore, the overall height of the dust cover 40 is reduced, and the central film portion 41 bulges in a meandering manner and expands in diameter.

Next, the dust cover 50 shown in FIG. 6 is a set ring mounting type for the socket 31, in which the central film portion 51 is preliminarily formed in a bellows shape, and the one end opening portion 52 is provided with another component set. A mounting groove 55 for mounting the 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 53. The set ring 54 is mounted in the mounting groove 55 after expanding the inner diameter thereof with a tool, and after mounting, it is elastically reduced 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 fitting type dust cover 40 has an advantage that it can be fastened to the socket 31 by a simple method of pushing the annular metal fitting 44 onto the outer periphery of the fastening portion 35 to fit it, but has the following problems. It was That is, as shown by the chain double-dashed line in FIG. 5, 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 made to follow the deformation of the dust cover 40. Needs to be increased. Then, as described above, the dust cover 40 was formed into a bell shape having a large overall height and then compressed into a large size. However, when the dust cover 40 is greatly compressed 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, and I was worried that I would get caught between 31 and stud 33. Therefore, in a ball joint having a large swing angle (for example, 24 degrees or more), such a fitting type dust cover 40 has not been established.

On the other hand, in the latter set ring mounting type dust cover 50, since the central membrane portion 51 is formed in advance in a bellows shape advantageous for securing the membrane length, the dust cover 50 can be installed in an automobile like the dust cover 40. There is no need to greatly compress when assembling. For this reason, there is no concern about the above-mentioned bite, and there is an advantage that it can be established even in a ball joint with a large swing angle. However, since the set ring 54 is a separate part and its mounting is troublesome, the number of parts increases, the assembly process becomes complicated, and the cost increases.

The object of the present invention is to solve the above-mentioned problems, to be established even in a ball joint having a large swing angle, and to reduce the number of parts, simplify the assembling process, and reduce the cost. It is to provide a dust cover for ball joints.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, according to the present invention, a central membrane portion is curved to secure a membrane length, one end opening portion is fastened to the socket outer periphery, and the other end opening portion is fitted to the stud outer periphery. In the dust cover, the central membrane part is formed in a bellows shape in advance, and an annular metal fitting that can be fitted to the outer circumference of the socket is integrally molded at the one end opening, and the inner diameter of the annular metal fitting is set to the maximum of the central membrane part. We took the measure of setting it larger than the inner diameter.

[0009]

[Action]

 In the dust cover of the present invention, the central membrane part is preliminarily formed into a bellows shape that is advantageous for securing the membrane length, so it is necessary to greatly compress the dust cover when assembling it to an automobile to expand the central membrane part in a meandering manner. There is no. Therefore, even if the swing angle of the stud is large, there is no concern that part of the central film portion will be caught between the socket and the stud, and this is also true for a ball joint having a large swing angle. Further, since the annular metal fitting that can be fitted to the outer circumference of the socket is integrally formed in the opening at one end, the annular metal fitting can be fastened to the socket by a simple method of pushing the outer circumference of the fastening portion and fitting. The central membrane part is molded by arranging a bellows-shaped mold inside it, but since the inner diameter of the annular metal fitting was set to be larger than the maximum inner diameter of the central membrane part, the annular metal fitting was formed after molding. In particular, it can be easily withdrawn from the portion forming the maximum inner diameter).

[0010]

【Example】

 An embodiment of a dust cover embodying the present invention will be described below with reference to FIGS. First, the ball joint 1 to which the dust cover is attached will be briefly described. Reference numeral 2 is a socket, a flange 3 is integrally projectingly provided on the outer periphery of the socket, and an upper half of the flange 3 is provided with a dust cover. The fastening portion 4 is notched. The reason why the fastening portion 4 is provided on the flange 3 to increase the outer diameter of the same in this manner is to correspond to the setting of the inner diameter of the annular metal fitting to be large, as described later. Reference numeral 5 denotes an accommodation chamber that is recessed from the upper surface of the socket 2 to the inside, and 6 denotes a synthetic resin ball seat 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 so as not to be able to be pulled out and which is in sliding contact with the ball seat 6. Reference numeral 10 denotes a flange-shaped plate fixed to the outer periphery of the shaft portion 8 of the stud 7.

Now, the dust cover 20 of this embodiment is of a type that fits into the socket 2, and as shown in FIG. 2, its central film portion 21 is formed in a bellows shape in advance, and the one end opening portion 22 has An annular metal fitting 24 that can be fitted to the outer periphery of the fastening portion 4 is integrally formed, and a seal portion 25 that slidably contacts the plate 10 is formed on the inner periphery of the other end opening portion 23. Further, the inner diameter B of the annular metal fitting 24 is set to be larger than the maximum inner diameter A of the central film portion 21. Therefore, after the central film portion 21 is formed by arranging the bellows-shaped mold 11 therein, the annular metal fitting 24 is easily removed from the mold 11 (particularly, the portion forming the maximum inner diameter A). be able to. Further, the inner peripheral edge of the annular metal fitting 24 before the fitting is formed so that the metal thin plate is bent obliquely upward, and the inner diameter B of the annular metal fitting 24 is set to be slightly smaller than the outer diameter C of the fastening portion 4 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 4.

Then, as shown in FIG. 3, the one-end opening 22 of the dust cover 20 is fitted into the socket 2 to complete the assembly of the ball joint 1. At this time, the other end opening 23 of the dust cover 20 is located immediately above the plate 10. Next, when the ball joint 1 is assembled to an automobile, as shown in FIG. 1, the dust cover 20 is pressed downward by the knuckle 12, and the other end opening 23 is fitted onto the plate 10. At this time, the total height of the dust cover 20 is slightly reduced, but the diameter of the central membrane portion 21 which is formed in the bellows shape in advance is not expanded. For this reason, even if the swing angle of the stud 7 is large, there is no tendency for a part of the central film portion 21 to be caught between the socket 2 and the stud 7. Holds even for large ball joints. Further, since the annular metal fitting 24 is integrally formed in the opening 22 at one end, the annular metal fitting 24 can be fastened to the socket 2 by a simple method in which the annular metal fitting 24 is pushed into the outer periphery of the fastening portion 4 and fitted.

The present invention is not limited to the configuration of the above-described embodiment, and may be embodied by being arbitrarily modified within a range not departing from the spirit of the invention.

[0014]

[Effect of device]

 Since the dust cover of the present invention is configured as described above, it can be applied to a ball joint having a large swing angle, and is excellent in that it can reduce the number of parts, simplify the assembly process, and reduce the cost. Produce an effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a dust cover of an embodiment embodying the present invention and a ball joint equipped with the dust cover when assembled in an automobile.

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

FIG. 3 is a cross-sectional view of a ball joint equipped with the dust cover.

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

FIG. 5 is a cross-sectional view of the ball joint when assembled in an automobile.

FIG. 6 is a cross-sectional view of a ball joint equipped with another conventional dust cover.

[Explanation of symbols]

1 Ball Joint 2 Socket 3 Flange 4 Fastening 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 Seal Part A Maximum Inner Diameter of Central Membrane Part B Annular Metal Fitting Inner diameter of

Claims (1)

[Scope of utility model registration request] 1. A dust cover of a ball joint in which a central film portion is curved to secure a film length, one end opening portion is fastened to an outer circumference of a socket, and the other end opening portion is externally fitted to an outer circumference of a stud. The part is formed in a bellows shape in advance, an annular metal fitting that can be fitted to the outer circumference of the socket is integrally formed in the one end opening, and the inner diameter of the annular metal fitting is set to be larger than the maximum inner diameter of the central membrane portion. Dust cover for ball joints.