JPH0768591A - Manufacture of gasket - Google Patents

Abstract

PURPOSE:To provide a manufacture of a gasket integrated with a work by avoiding the occurrence of flashes. CONSTITUTION:This method is to integrally manufacture a gasket on the sealed surface 12 of a work W and, at first, a resin material is injected into the cavity 24 defined between a pair of molds 20, 21 for molding a seal-molded body 16. Thereafter, mold opening is so performed that a seal-molded body 16 is allowed to remain on one mold 20, and the seal surface 12 of the work W is brought into contact with the seal-molded body 16 under a predetermined pressure force to block the groove 13 of the work W. Then, the resin material being the same kind as the seal-molded body 16 is injected into the blocked groove 13. The seal retainer 17 molded within the groove 13 is integrated with the seal-molded body 16 to thus be a gasket 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a gasket, and more particularly to a method of manufacturing a gasket integrated with a metal part.

[0002]

2. Description of the Related Art Conventionally, a gasket such as a rubber ring or a metal ring has been used for imparting a predetermined sealing effect between various machines, particularly automobile parts and the like. In many cases, this type of gasket is individually formed by a predetermined molding method, and then the gasket is interposed on the sealing surface between the components.

However, in this case, the work of mounting the individually formed gaskets on the component sealing surface is inevitable, resulting in not only an increase in the number of working steps but also a problem such as a gasket mounting error. It was

Therefore, when a resin material such as silicone rubber is used as a gasket molding material, a work such as an automobile part is previously inserted into a molding die including a male die and a female die, and the die is formed. An insert molding method is known in which a resin material is injected into a cavity formed between a sealed surface of a work and a mold after tightening to obtain a gasket integrated with the work.

[0005]

However, in this case, it is not always easy to secure the adhesion between the male die and the work, and a fine clearance may be formed on the contact surface between the die and the work, so that the gasket molding is performed. Even if a resin material for injection is injected, the material will enter the clear run and form burrs, which will significantly impair the appearance of the product, and the loss of injection pressure due to the formation of burrs and unnecessary material consumption. Alternatively, there is an inconvenience of causing a short mold or the like.

In this case, in order to improve the adhesion between the molding die and the work, it is conceivable to increase the plane accuracy of the work or increase the pressure applied to the work, but the work requiring high precision machining. It is unavoidable that productivity is lowered and cost is increased, and the method of increasing the pressing force is not preferable because it causes damage to the work due to the pressing force or damages the molding die.

In the insert molding described above, it is possible to mold a gasket on the sealed surface of the work using a molding die made of resin. However, due to the pressing force at the time of molding, etc. In addition to insufficient durability, it is not always possible to efficiently mold a gasket having a good product appearance in terms of thermal conductivity and mold releasability.

[0008]

SUMMARY OF THE INVENTION The present invention has been devised in order to improve the disadvantages of the conventional example, and an object thereof is to avoid the formation of burrs and improve the appearance of the product to be integrated with the work. Another object of the present invention is to provide a method of manufacturing a gasket.

[0009]

In order to achieve the above object, a method for manufacturing a gasket according to the present invention is a method for manufacturing a gasket on a sealed surface of a work having a groove formed along the sealed surface. , A resin material is injected into a mold cavity corresponding to a predetermined gasket shape to form a seal molding, and after the mold is opened, the sealed surface of the work is brought into contact with the seal molding to close the groove of the work. After that, a method is adopted in which a resin material is injected into the groove to mold a seal holder, and the seal holder and the seal molded body are integrated.

When molding the gasket,
It is preferable that the seal molded body and the seal holder are molded from the same resin material.

[0011]

In the present invention, the seal molded body forming the gasket is first formed by injection molding, the mold used for this molding is opened, and the sealed surface of the work is brought into contact with the seal molded body. Pressurize. In this state, the groove along the surface to be sealed of the work is closed by the seal molding to form a cavity. At this time, the seal molded body is closely adhered to the surface to be sealed in conformity with the surface roughness, so that the clearance that may cause burrs is wiped out. A resin material is injected into the cavity thus formed to form a seal holder, and the seal holder is integrated with the seal molded body.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a gasket manufacturing method according to the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing a gasket integrated with a work by the manufacturing method in this embodiment, and FIG. 2 is an enlarged sectional view taken along the line AA of FIG. In these drawings, an aluminum workpiece W formed by die casting such as an engine head cover of an automobile has a bottom wall 10 formed in a substantially rectangular shape and the bottom wall 1
It has a peripheral wall 11 erected from the periphery of 0, and has an opening at the upper end side. The opening side end of the peripheral wall 11 is formed as a flat surface as the sealed surface 12, and a groove 13 is formed in the central portion thereof along the extending direction of the sealed surface 12, that is, the circumferential direction.

A gasket 15 is provided in the groove 13 and part of the surface 12 to be sealed. In the present embodiment, the gasket 15 is formed of a two-liquid addition reaction low temperature heating and fast curing type silicone rubber, but various resin materials can be adopted depending on the application of the work W.
The gasket 15 is composed of a seal molding 16 above the surface 12 to be sealed, and a seal holder 17 which is integrated with the seal molding 16 and holds the seal molding 16 on the work W. There is.

Next, a specific method of manufacturing the gasket 15 will be described with reference to FIGS.
Will be described in detail with reference to.

First, as shown in FIG. 3, the above-mentioned seal molding 16 includes a fixed side mold 20 and a fixed side mold 2.
It is molded by a movable mold 21 that can move relative to zero. The fixed mold 20 is provided with an ejector pin 22 that can move forward and backward. Both molds 2 in the mold clamped state
A cavity 24 corresponding to the seal molding 16 is formed between 0 and 21. At this time, it is preferable that the ejector pin 22 has a shape corresponding to the shape of the seal molding pair 16 so that a thin flash does not appear and the sealing property is not deteriorated.

Following the state where the fixed side mold 20 and the movable side mold 21 are clamped, a resin material is injected into the cavity 24 and cured to form a seal molding 16 as shown in FIG. Let it complete.

After the molding of the seal molding 16 is completed in this way, the movable mold 21 is separated from the fixed mold 20 and the mold is opened (see FIG. 5). At this time, in this embodiment, a method in which the seal molded body 16 is left in the fixed side mold 20 is adopted. As a method of leaving the seal molded body 16 in the fixed-side mold, it can be achieved without difficulty by setting the contact area of the seal molded body 16 with respect to the fixed-side mold 20 to be larger than the contact area with the movable-side mold 21. be able to.

Next, the sealed surface 12 of the work W as shown in FIG. 1 is arranged so as to abut the seal molding 16 (see FIG. 6). In this state, the groove 13 formed along the seal surface 12 of the work W serves as a cavity. At this time, since the seal molding 16 that is in contact with the sealing surface 12 is a resin material such as silicone rubber, the seal molding 16 adheres to the sealing surface 12 following the surface roughness of the sealing surface 12, and burrs may occur. Without causing any clearance.

The work W is pressed against the sealed surface 16 from above in the figure with the sealed surface 12 and the seal molded body 16 in contact with each other, and the resin material is injected into the groove 13 in this state. Then, the seal holder 17 is molded in the groove 13 (see FIG. 7). At this time, in this embodiment, the material of the seal holder 17 is the same as that of the seal molding 16. When the injection into the groove 13 is completed, the seal holding body 17 and the seal molding body 16 are made of the same material, so that the seal holding body 17 and the seal molding body 16 are bonded and fixed to each other, and the integrated gasket 15 is molded.

After the gasket 15 is formed in this manner, the above-mentioned pressing force is released, and the ejector pin 22 is projected and released from the mold, whereby the gasket as a product integrated with the work W is obtained. 15 can be obtained.

Therefore, according to such an embodiment, it becomes possible to wipe out the clearance that may be caused by the surface roughness of the seal surface 12 of the work W by the seal molded body 20, and the occurrence of burrs is effective. There is an effect that it is possible to form a gasket capable of avoiding the above and maintaining a good appearance of the product. Moreover, in this case, since there is no gap in which burrs can occur, it is possible to obtain the effect of preventing loss of injection pressure and unnecessary material consumption.

The seal molding 16 for the work W is also provided.
Since the adhesion of the workpiece W is improved, the processing accuracy of the workpiece W,
In other words, even if the plane accuracy is not so high, any inconvenience does not occur, so that high-precision machining of the work W is not required and the productivity itself of the work W may not be reduced.

Further, since the pressure applied to the work W is sufficient to ensure the close contact with the seal molding 16, the cause of the damage of the work W can be avoided.

In the description of the above-mentioned embodiment, the mode in which the seal molding 16 is placed on the stationary mold 20 is illustrated and described, but this mode is not limited in carrying out the method of the present invention. However, the present invention can be implemented in the same manner even if it is appropriately changed depending on the type of press machine used.

Further, the overall shape of the gasket 15 in the illustrated example is a schematic one for convenience of explanation, and the cross-sectional shapes of the seal molded body 16 and the seal holding body 17 are used for the work W and the like. It is of course possible to form the gasket 15 into another shape such as an arcuate shape according to the above.

Further, the material of the gasket molding material is not particularly limited, and can be appropriately selected according to various conditions such as the relative relationship with the applied work W. Further, in the above-described embodiment, the case where the seal molded body 16 and the seal holding body 17 are molded with the same resin material has been described, but the seal molded body 16 and the seal holding body 17 are different resin materials from each other. Of course, it is also possible to mold with.

[0028]

The present invention is constructed as described above, and
Since it works, even if the surface to be sealed of the work is not processed with high precision, the seal molded body can be brought into close contact according to its surface roughness, and burrs are generated when molding the seal holder. Manufacture of gaskets that have an unprecedented excellent effect that post-treatment is unnecessary by cleaning the gaps and the appearance of the gasket integrated with the work W as the final product can be maintained well. A method can be provided.

[Brief description of drawings]

FIG. 1 is an external perspective view showing a gasket integrally formed with a work by a gasket manufacturing method according to the present invention.

FIG. 2 is an enlarged sectional view taken along the line AA of FIG.

FIG. 3 is a cross-sectional view schematically showing an initial mold clamping state in a stage before molding a seal molded body.

FIG. 4 is a cross-sectional view showing a state in which a seal molded body is injection molded.

FIG. 5 is a cross-sectional view showing a mold open state after molding a seal molded body.

FIG. 6 is a cross-sectional view showing a state in which the seal surface of the work is in contact with the seal molded body.

FIG. 7 is a cross-sectional view showing a state in which a seal holder is injection-molded in a groove of a work.

FIG. 8 is a cross-sectional view showing a state in which a gasket integrated with a work piece is projected.

[Explanation of symbols]

 12 Sealed Surface 13 Groove 15 Gasket 16 Seal Formed Body 17 Seal Holding Body 24 Cavity W Work

Claims (2)

[Claims] 1. A groove (13) is formed along the surface to be sealed (12).
In a method of manufacturing a gasket (15) on the sealed surface (12) of a work (W) having a seal formed therein, a resin material is injected into a mold cavity (24) corresponding to a predetermined gasket shape, and seal molding is performed. The body (16) is molded, and after the mold is opened, the sealed surface (12) of the work (W) is brought into contact with the seal molded body (16) to form the groove (13) of the work (W).
After that, a resin material is injected into the groove (13) to mold a seal holder (17), and the seal holder (17) and the seal molded body (16) are integrated. A method of manufacturing a gasket, which is characterized by the following. 2. The method for manufacturing a gasket according to claim 1, wherein the seal molding (16) and the seal holder (17) are molded of the same resin material.