JPH078903Y2 - Sealing device - Google Patents

Description

[Detailed Description of the Invention] (Industrial field of application) This invention integrates a reinforcing ring and a rubber-like elastic body by vulcanization molding like a dust cover for a ball joint of a tie rod of a steering device for an automobile. The present invention relates to a sealing device.

(Prior Art) FIGS. 4 and 5 show a dust cover 100 for a ball joint as a conventional sealing device. Dust cover 100
The inner periphery of the rubber-like elastic body 101 of the rubber-like elastic body is in close contact with the stud 103 assembled to the joint 102, and the free end of the skirt portion 104 extending to the outer periphery is the socket 105. It is fixed to the fixing groove 106. Further, grease (not shown) is sealed inside the dust cover 100.

On the other hand, an annular reinforcing ring 107 is embedded in the main body 101 to secure the adhesion to the stud 103. Further, a dust lip 108 as an annular seal lip is provided on the outer peripheral side of the main body portion 101, and is in close contact with the lower surface of the knuckle arm 109.

On the inner peripheral side of the main body 101 at a location corresponding to the dust lip 108, ring receiving portions 110 are formed as a plurality of through holes along the circumferential direction (see FIG. 6). The ring receiving portion 110 is formed during vulcanization molding of the dust cover 100. That is, the reinforcing ring 107 is first placed on a plurality of pins provided along the circumferential direction at the bottom of the cavity (not shown). Then, when a mold is heated and pressed after placing a rubber cloth (not shown), the fluidized rubber spreads into the cavity and is solidified into a predetermined shape. Then, when the solidified rubber and the reinforcing ring 107 are taken out from the cavity, the cavity where the pin was present remains as the ring receiving portion 110. By the way, in the molded article vulcanized and molded in the cavity, the rubber-like elastic body portion contracts in the radial direction as it cools.

(Problems to be solved by the invention) However, since the dust lip 108 is provided in close contact with the ring receiving portion 110, the rigidity of the main body portion 101 corresponding to the dust lip 108 on the outer peripheral side of the ring receiving portion 110. Is not enough. As a result, due to the contraction, the main body 101 located on the outer peripheral side of the ring receiving portion 110 is dented inward (wavy shape as a whole dust cover), and not only does it look bad in appearance but also wavy. If the phenomenon is large, the sealing performance of the dust lip 108 may be adversely affected.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a sealing device in which the rigidity of a portion corresponding to a seal lip of the main body is enhanced.

(Means for Solving the Problems) In order to achieve the above object, the present invention relates to a reinforcing ring that is held on a plurality of pins provided along the circumferential direction at the bottom of an annular cavity, and to this reinforcing ring. On the other hand, it has an annular main body made of a rubber-like elastic body integrated by vulcanization molding and is a main body portion corresponding to the outer peripheral side of the plurality of through holes where the pins were located at the time of vulcanization molding. In a sealing device provided with an annular seal lip, an annular rigidity reinforcing portion having a predetermined radial dimension is provided between the main body portion corresponding to the seal lip and a plurality of through holes. is there.

(Operation) The present invention based on the above configuration is an annular main body made of a rubber-like elastic body adhered to a reinforcing ring by vulcanization molding in a cavity, and a portion corresponding to the dust lip is
The rigidity is increased in combination with the rigidity reinforcing portion having a predetermined radial dimension.

(Embodiment) Next, an embodiment of the present invention will be described with reference to FIGS.

In the figure, reference numeral 1 denotes a ball joint dust cover as a sealing device. The inner circumference of the rubber-like elastic body 2 that constitutes the dust cover 1 is in close contact with the stud 4 assembled to the joint 3, and
The free end of the skirt portion 5 extending to the outer peripheral side is fixed to the fixing groove 7 of the socket 6 by a fixing tool 5a such as a wire. Further, grease (not shown) is filled inside the dust cover 1 to lubricate the sliding portion between the stud 4 and the joint 3.

On the other hand, the main body 2 has an annular reinforcing ring 8 having an L-shaped cross section.
To secure adhesion to the stud 4. Further, a dust lip 9 serving as an annular seal lip is provided on the upper surface on the outer peripheral side of the main body portion 2 and is in close contact with the lower surface of the knuckle arm 10.

On the inner peripheral side of the body portion 2 corresponding to the dust lip 9, ring receiving portions 11 are formed as a plurality of through holes along the circumferential direction. Also, the main body 2
And a portion corresponding to the dust lip 9 and the ring receiving portion 11
An annular straight portion (rigidity-reinforcing portion) 12 having a radial dimension 1 in a predetermined direction is provided between and.

The ring receiving portion 11 and the straight portion 12 are formed in the main body portion 2 as follows.

First, a plurality of pins (for example, six at 60 ° intervals) are provided along the circumferential direction at the bottom of the cavity of a mold (not shown), and the reinforcing ring 8 is placed on the pins.
Put the rubber material and heat the mold. Pressurize. Then, the rubber material is fluidized and adhered to the reinforcing ring 8 and solidified throughout the cavity, and the entire rubber-like elastic body portion has a predetermined shape, and the dust lip 9 and the straight portion 12 are formed. Here, it goes without saying that the mold is designed in advance so that the straight portion 12 is formed on the outer peripheral side of the pin.

Then, the mold is opened, the molded product is taken out, and the rubber-like elastic body portion may be cut. When the molded product is taken out from the cavity, the place where the pin has been present becomes a cavity and the ring receiving portion 11 is formed. On the other hand, the molded product vulcanized and molded in the cavity cools with the passage of time and contracts in the radial direction (ignoring the axial direction at this time) as a whole, but corresponds to the dust lip 9 in the main body 2. In combination with the straight portion 12, the portion to be made has a large radial dimension and a high rigidity against a radial load. Therefore, the above-mentioned contraction does not cause a problem that the portion of the main body 2 corresponding to the dust lip 9 is dented inward and wavy as a whole, and the appearance is good and the knuckle arm is good.
It is possible to secure the sealing property with respect to 10.

Further, as described above, since the straight portion 12 is formed during the vulcanization molding of the reinforcing ring 8 and the main body portion 2 (fluid rubber), there is no problem in molding and there is no fear that the manufacturing cost will increase. .

(Effect of the Invention) Since the present invention is configured as described above, even if the main body portion contracts in the radial direction due to cooling during molding, the portion of the main body portion that corresponds to the seal lip is dented inward. In this way, there is no problem of wavy shape as a whole, the appearance is good, and the sealing property of the seal lip can be secured.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a half of a main part in which the present invention is applied to a dust cover for a ball joint, FIG. 2 is a front sectional view showing a half of the overall schematic configuration of the same embodiment, and FIG. 3 is the same embodiment. FIG. 4 is a plan view showing a half of an example, FIG. 4 is a front sectional view showing a half of an overall schematic configuration of a conventional ball joint dust cover, FIG. 5 is a sectional view showing an essential part of FIG. 4, and FIG. It is a top view of FIG. Explanation of reference numerals 1 ... Dust cover (sealing device) for ball joint 2 ... Main body part, 3 ... Joint 4 ... Stud, 5 ... Skirt part 5a ... Fixing tool, 6 ... Socket 7 ... Fixing groove, 8 ... Reinforcing ring 9 ... D Strip, 10 ... Knuckle arm 11 ... Ring receiving part (through hole) 12 ... Straight part (stiffening part) l ... Radial dimension

Claims (1)

[Scope of utility model registration request] 1. A reinforcing ring held on a plurality of pins provided along the circumferential direction at the bottom of an annular cavity, and a rubber-like elastic body integrated with the reinforcing ring by vulcanization molding. In a sealing device having an annular main body made of, and having an annular seal lip at a portion corresponding to the outer peripheral side of the plurality of through holes in which the pins were located at the time of vulcanization molding in the main body, the main body A sealing device, characterized in that an annular rigid reinforcing portion having a predetermined radial dimension is provided between a portion corresponding to a seal lip and a plurality of through holes.