JPH0583442U - Dust cover for ball joint - Google Patents

Abstract

(57) [Abstract] [Purpose] Prevents the grease discharge port 2 from being pressed against the lower surface of the knuckle arm and blocked when the dust cover expands during grease discharge, and the grease cannot be discharged. To do. [Structure] A protrusion 6 is provided on a part of the periphery of the grease discharge port 2, and when the dust cover expands when discharging the grease, the protrusion 6 is brought into contact with the lower surface of the knuckle arm so that the grease discharge port 2 can be kept in contact with the knuckle arm. Prevents pressure contact with the lower surface of the.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to improvement of a dust cover for a ball joint.

[0002]

[Prior Art]

 Conventionally, as shown in FIG. 5, it is mounted between a ball stud 21 provided with a knuckle arm 22 and a socket 23, and grease (not shown) is sealed inside, so that the substantially lantern-shaped membrane portion 1 is attached. There is known a dust cover for a ball joint in which a grease discharge port 2 is provided in the film portion 1. The film portion 1 is formed of a rubber-like elastic material, and thus has the flexibility of being freely deformed according to the swing of the ball stud 21. As shown in FIG. 6 and FIG. 7, the grease discharge port 2 is provided with a concave portion 3 on the inner surface of the film portion 1 to form the thin film portion 4 at the portion where the concave portion 3 is provided, and the thin film portion 4 is linearly formed. A single slit 5 is formed, and old grease is discharged from this slit 5 when the grease is replaced.

[0003]

[Problems to be solved by the device]

 The above conventional technique has the following problems. That is, when the grease is discharged, the dust cover expands before the grease is discharged from the grease discharge port 2 in association with the increase in the internal pressure of the dust cover, and as shown in FIG. May be pressed against the lower surface of the knuckle arm 22 to be blocked and the grease cannot be discharged.

[0004]

[Means for Solving the Problems]

 In view of the above points, the present invention has been devised to solve the above-mentioned problems in the prior art. In order to achieve this object, the dust for ball joints provided with a grease discharge port in the film part. A dust cover for a ball joint, characterized in that a protrusion is provided on a part of the periphery of the grease discharge port.

[0005]

[Action]

 If a protrusion is provided on part of the periphery of the grease outlet, when the dust cover expands during grease discharge, this protrusion makes contact with the lower surface of the knuckle arm, and the grease outlet comes into pressure contact with the lower surface of the knuckle arm. Can be prevented. However, if the protrusions are provided all around the grease outlet, the protrusions will have an annular shape, and when the protrusions come into contact with the lower surface of the knuckle arm, the grease will extend around the entire periphery of the grease outlet. The grease will not be able to be discharged to the outside even if the grease outlet is not pressed directly against the lower surface of the knuckle arm. In the present invention, the protrusion is provided in a part of the periphery of the grease discharge port in order to prevent such inconvenience, and therefore the protrusion is formed in a non-annular shape. The non-annular shape includes various shapes such as a dot shape, a linear shape, an arc shape, or a substantially C shape. Further, the number of protrusions formed may be one or plural.

[0006]

【Example】

 Next, an embodiment of the present invention will be described with reference to the drawings. The dust cover for a ball joint is mounted between a ball stud equipped with a knuckle arm and a socket, filled with grease, and is a lantern-shaped membrane. And a grease discharge port is provided in the film part, and further has the following configuration. That is, as shown in FIGS. 1 and 2, one point-like projection 6 is provided on the outer surface of the film portion 1 next to the grease discharge port 2, and the projection 6 expands the grease discharge port 2. It has a higher height. Further, in another embodiment shown in FIGS. 3 and 4, one arc-shaped projection 7 is provided on the outer surface of the film portion 1 so as to surround the grease discharge port 2, and this projection 7 is also the grease discharge port. It has a height higher than the bulge of 2. However, according to the dust cover having the protrusions 6 and 7, when the dust cover expands when the grease is discharged, the protrusions 6 and 7 come into contact with the lower surface of the knuckle arm and the grease discharge port. 2 can be prevented from coming into pressure contact with the lower surface of the knuckle arm, and the grease can be reliably discharged to the outside from the gap formed between the grease discharge port 2 and the knuckle arm.

[0007]

[Effect of the device]

 The present invention has the following effects. That is, a protrusion is provided on a part of the periphery of the grease outlet to prevent the protrusion from coming into contact with the lower surface of the knuckle arm when the dust cover expands, and preventing the grease outlet from pressing against the lower surface of the knuckle arm. Since it is configured, the grease can be reliably discharged to the outside from the gap formed between the grease discharge port and the knuckle arm.

[Brief description of drawings]

FIG. 1 is a sectional view of a main part of a ball joint dust cover according to an embodiment of the present invention.

FIG. 2 is a view in the direction of arrow A in FIG.

FIG. 3 is a sectional view of a main part of a ball joint dust cover according to another embodiment of the present invention.

FIG. 4 is a view in the direction of arrow B in FIG.

FIG. 5 is a sectional view of the ball joint.

FIG. 6 is a sectional view of a main part of a ball joint dust cover according to a conventional example.

FIG. 7 is a view in the direction of arrow C in FIG.

FIG. 8 is a sectional view of an essential part showing the operation of the ball joint dust cover.

[Explanation of symbols]

 1 Membrane 2 Grease Discharge Port 3 Recess 4 Thin Wall 5 Slit 6, 7 Protrusion 21 Ball Stud 22 Knuckle Arm 23 Socket

Claims (1)

[Scope of utility model registration request] 1. A ball joint dust cover having a grease discharge port 2 in a film portion 1, wherein projections 6 and 7 are provided in a part of the periphery of the grease discharge port 2. cover.