JPH066827U - Mold for gasket molding - Google Patents

Abstract

(57) [Summary] [Purpose] To reduce molding defects, reduce finishing processes, and improve the sealing performance of gaskets as products. A gasket molding die for integrally molding an annular beat 2 on a surface of a plate 1, the plate 1 comprising:
The inner surface 13a of the cavity 13 facing the surface of the plate 13 has a required number of protrusions 14 projecting in an inclined shape with respect to the surface of the plate 1 on the outer diameter side or the inner diameter side.
The injection gate 15 is opened in a.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a metal mold for molding a gasket integrally provided with an annular ring beat made of an elastomer that elastically adheres to a mating member on the surface of a plate.

[0002]

[Prior art]

 Conventionally, as a kind of gasket, for example, as shown in FIG. 4 to FIG. 6, a structure in which an annular beat 102 made of an elastomer is integrally formed on the surface of a plate 101 is used. It is clamped and fixed between the members A and B by a fixing bolt (not shown) inserted through the hole 101a, and the upper surface of the beat 102 is brought into close contact with the mating member A with an appropriate pressure contact force over the entire circumference, so that the spaces between the inner and outer sides thereof are There is something to block.

As shown in FIG. 7, the above-described gasket has a plate 101 sandwiched between a lower mold 111 and an upper mold 112 facing the lower mold 111, and the plate 101 is bonded to the surface of the plate 101 in the upper mold 112. Inside the annular cavity 113 formed in the contact surface, a flat groove 114 extending from the circumferentially equidistant positions of the cavity 113 along the abutment surface to the outer peripheral side, and toward the inside of the groove 114. It is molded by injecting a molding elastomer material through the opened injection gate 115. Therefore, in the gasket as a product, a plurality of thin plate-shaped elastomer pieces 103 that stick out from the outer periphery of the beat 102 at the circumferentially equidistant positions and adhere to the plate 101 are present at the position of the groove 114. ing.

[0004]

[Problems to be solved by the device]

 However, according to the prior art, the molding elastomer material is injected into the cavity 113 from the injection gate 115 through the flat passage between the groove 114 and the plate 101, so that the flow resistance of the material is increased and the cavity 113 is increased. Insufficient filling (lack of thickness) occurred due to shot shots to the beet 102, resulting in defective molding of the beat 102. Further, in order to prevent the occurrence of such a molding defect, the height H of the groove 114 of the upper mold 112 may be increased. However, in the above-described gasket, as shown in FIG. Since it is attached to the end surface of the mating member A in a pressure-bonded state, by increasing the height H of the groove 114, if the wall thickness T of the elastomer piece 103 on the outer periphery of the beat 102 increases, the member A, It becomes difficult to make the tightening force of the plate 101 uniform between B, which may adversely affect the sealing property. Further, since the high pressure of the molding elastomer material from the injection gate 115 acts on the flat passage formed between the groove 114 and the plate 101, the beat 102 is surrounded by the surface of the plate 101. Thin burrs are apt to occur due to the material wrapping around, so a finishing process for removing burrs was required after molding.

The present invention has been made under the circumstances as described above, and its technical problems are to reduce molding defects, finish steps, and sealability of a gasket as a product. It is to improve.

[0006]

[Means for Solving the Problems]

 The above technical problems can be effectively solved by the present invention. That is, the present invention relates to a gasket molding die for integrally molding an annular beat made of an elastomer on the surface of a plate, in which the plate is placed on the outer diameter side or the inner diameter side of the inner surface of the cavity facing the surface of the plate. It has a required number of protrusions protruding in a slanted shape with respect to the surface, and an injection gate is opened in the inclined surface of this protrusion.

[0007]

[Action]

 According to the gasket molding die of the present invention, the molding elastomer material is filled into the cavity from the gate opening on the inclined surface of the convex portion protruding on the outer diameter side or the inner diameter side of the inner surface of the cavity. Since it does not pass through the narrow groove as in the conventional case, the filling rate of the material is increased, and defective molding of the beat due to lack of thickness is prevented. In addition, since the gasket thus obtained has no elastomer piece protruding around the beat, the plate can be attached to the mating member over the entire circumference and can be mounted with a constant tightening force.

[0008]

【Example】

 FIG. 1 shows an embodiment of a gasket molding die according to the present invention, in which 11 is a lower die and 12 is an upper die opposed to the lower die 11. In molding, upper and lower dies 11 and 12 are used. The metal plate 1 of the gasket is sandwiched between the two. An annular cavity 13 is formed in the contact surface 12a of the upper die 12 with the surface of the plate 1 described above. Of the inner surfaces of the cavity 13, the outer diameter of the inner surface 13a facing the surface of the plate 1 is defined. On the side, a plurality of convex portions 14 (only one place is shown in FIG. 1) having a shape inclined with respect to the surface of the plate 1 are provided so as to be evenly distributed in the circumferential direction. An injection gate 15 of a molding elastomer material is opened in the inclined surface 14a. The center line O of the injection gate 15 is perpendicular to the inclined surface 14a, that is, is inclined at the same angle as the inclination angle of the inclined surface 14a with respect to the perpendicular line standing on the surface of the plate 1. There is.

As shown in FIGS. 2 and 3, the gasket molding die of the above embodiment is for obtaining a gasket in which an annular beat 2 made of an elastomer is integrally molded on the surface of a plate 1. Is. That is, according to this gasket molding die, since the molding elastomer material does not pass through the flat groove as in the conventional process in the process of being injected into the cavity 13, the filling is smoothly performed and the beat by the short shot is beaten. No defective molding of 2 occurs. Further, since the high-pressure molding elastomer material from the injection gate 15 is not injected into the cavity 13 through the surface of the plate 1, thin burr from the cavity 13 along the surface of the plate 1 does not occur.

In the beat 2 molded by this gasket molding die, a concave portion 3 corresponding to the convex portion 14 of the upper die 12 is formed on the upper surface 2a which is a sealing surface for a mating member (see reference numeral A in FIG. 6). Although formed, the concave portions 3 are discretely formed in the circumferential direction at positions unevenly distributed on the outer diameter side of the upper surface 2a and have an inclined surface. Since the distortion is unlikely to occur and the trace of the gate cut portion is formed on the inclined surface of the concave portion 3, the sealability is not adversely affected by the gate trace. Also, since no conventional elastomer piece (see reference numeral 103 in FIGS. 4 and 5) is formed around the beat 2, the plate 1 should be attached in close contact with the mating member over the entire circumference and fixed with a constant tightening force. You can

In this embodiment, the convex portion 14 with the opening of the injection gate 15 is provided at a position eccentrically located on the outer diameter side of the inner surface 13a of the cavity 13. However, depending on the usage conditions of the product gasket. May be unevenly distributed on the inner diameter side, the size and the number thereof, the angle of the inclined surface and the like are arbitrary, and the shape of other details is not limited.

[0012]

[Effect of device]

 The gasket molding die of the present invention has the following effects. (1) The filling property of the molding elastomer material into the cavity is improved, and defective beating of the beat due to short shots can be prevented. (2) Since the elastomer piece, which is the part that connects with the gate, is not formed around the molded beet, the plate can be brought into close contact with the mating member over the entire circumference and the tightening force can be made constant, resulting in stable sealing. You can get a gasket with. (3) Since the gate is formed in the concave portion of the beet and does not adversely affect the sealing property, it is possible to roughly process the gate trace and the gate burr. (4) Since burr is not easily formed on the plate surface, the finishing process can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of a gasket molding die according to the present invention.

FIG. 2 is a half-cut front view of a gasket obtained by the mold of the above embodiment.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a half-cut front view showing an example of a conventional gasket.

5 is a cross-sectional view taken along the line VV in FIG.

FIG. 6 is a partial cross-sectional view showing a mounted state of a conventional gasket.

FIG. 7 is a partial cross-sectional view showing an example of a conventional gasket molding die.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate 2 Beat 2a Upper surface 3 Recessed portion 11 Lower die 12 Upper die 12a Joining surface 13 Cavity 13a Inner surface 14 Convex portion 14a Sloping surface 15 Injection gate

Claims (1)

[Scope of utility model registration request] 1. A gasket molding die for integrally molding an annular beat (2) made of an elastomer on the surface of a plate (1), comprising a cavity (1) facing the surface of the plate (1).
On the outer diameter side or the inner diameter side of the inner surface (13a) of 3), there is a required number of protrusions (14) protruding in a shape inclined with respect to the surface of the plate (1). A mold for molding a gasket, characterized in that an injection gate (15) is opened in the inclined surface (14a).