JPS63312568A - Manufacture of packing - Google Patents

Abstract

PURPOSE:To improve the production efficiency by providing a process to arrange a ring like member into a mould and also providing a process to assemble the ring like member to a packing main body during the moulding of the packing main body in vulcanization. CONSTITUTION:A projection 5 is provided onto the lower mould 1 and an O-ring fitted into a packing is arranged onto the projection 5. Next, the second mould 2 is moved to be arranged onto the lower mould 1. Thus, a moulding cavity corresponding to an almost finished packing is finished by the lower mould 1 and the second mould 2. Inside the moulding cavity a rubber like elastic material for forming the packing is arranged. The upper mould 15 is closed to heat and press the rubber like elastic material 13 inside the moulding cavity. The heated and pressed material 13 is lowered while rotated around the O-ring 7. In this case, the force to press the O-ring downward is generated. The material 13 is further moved downward so as to fill the whole of the cavity. Then, the rubber like elastic material 13 is hardened and thereafter the mould is opened so as to take out the compact.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a packing having a recess in the center of the main body and a ring-shaped member fitted into the recess. The present invention relates to a method of manufacturing a packing that incorporates a ring-shaped member into a packing main body.

(Prior Art) Conventionally, as this type of U packing, there is a packing 100 shown in FIG. 4. This packing 100 is mainly used for low temperature and high pressure applications. The packing 100 has an outer lip 101 and an inner lip 102. A fitting groove 103 is provided between the outer lip 101 and the inner lip 102 and extends all the way around the circumference. Fitting groove 1
03 has a substantially V-shaped cross section, and has a recess 103a with a circular cross section at the bottom of the 7-shape. Bottom part 103a
An O-ring 104 is fitted to the 0-ring 104. With such a configuration, the outer lip 101 and the inner lip 102 are cooled at low temperatures.
Even if it hardens, each lip 101, 102 has a certain length, so it acts as an elastic beam, and the lips 101, 102 bend with the bottom of the fitting groove 103 as a fulcrum, and each lip No unreasonable force is applied to 1o1°102, surface pressure is maintained at an appropriate level, and sealing performance is maintained.

By the way, in the method for manufacturing such a packing 100, first, the packing 100 is manufactured alone.

The packing 100 is obtained by putting a rubber elastic material into a mold and vulcanizing it. Separately from this packing 100, an O-ring 104 is manufactured. Finally, the O-ring 104 was fitted to the bottom part 103a of the separately manufactured gasket 100 to complete the gasket 100.

(Problem to be Solved by the Invention) However, in the case of the prior art, the seal 100 and the O-ring 104 are manufactured separately, and the seal 100 is manufactured later.
Since this is a method of fitting the O-ring 104 to the bottom 103a, a final step of assembling the O-ring 104 and the packing 100 is required.

Further, the assembly work of assembling the O-ring 104 into the packing 100 is a slow process due to the shape of the packing 100, and the O-ring 104 remains twisted or stretched, that is, the stress is maintained in the O-ring 104. De Patsukin 1
00 may be included.

In addition, if the Q IJ song 04 is installed while the stress is maintained, the O-ring 104 may come off from the seal 100 after the seal 100 is installed in a predetermined position.
There was a problem that the sealing performance of the packing 100 could not be maintained.

The present invention was made to solve the problems of the prior art, and its purpose is to improve production efficiency by omitting the process of later assembling the O-ring, which is manufactured separately from the packing, into the packing. To provide a method for manufacturing a packing that can improve the performance of the packing and also securely fit the O-ring to the packing so that the O-ring does not come off from the packing.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a packing having a recess in the center of the main body and a ring-shaped member fitted into the recess. A manufacturing method comprising the steps of arranging a ring-shaped member in a mold, and incorporating the ring-shaped member arranged in the mold into the packing body during vulcanization molding of the packing body. Features.

(Function) According to the packing manufacturing method of the present invention, a protrusion is provided on the lower die of the mold. An O-ring to be fitted into the packing is placed on the protrusion of the lower mold.The second mold is then moved and placed on top of the lower mold. As a result, a molding cavity corresponding to the nearly completed packing is completed by the lower mold and the second mold. A rubber-like elastic material forming a packing is placed inside this molding cavity.

Next, the upper mold is closed and the rubber-like elastic material inside the molding cavity is heated and pressurized. The heated and pressurized rubber-like elastic material is
It goes around the O-ring placed on the protrusion and descends. At this time, a force is applied that presses down the 0 ring from above. The rubber-like elastic material moves further downward and fills the entire cavity.

After the rubber-like elastic material has hardened, the mold is opened, the molded product inside the molding cavity is taken out, and the excess portion is cut to obtain a finished product.

In this way, by placing the ring-shaped member in the mold in advance,
Since the ring-shaped member is incorporated into the packing during vulcanization molding of the packing, production efficiency can be improved by omitting the process of incorporating the O-ring into the packing.Furthermore, the O-ring can be reliably fitted into the packing. Therefore, the sealing performance of the seal is improved and the quality is improved.

(Example) The present invention will be explained below based on the illustrated example. 1st
Referring to Figure (a), l is the lower mold. A second mold 2 is arranged on the side of the lower mold 1. The lower die 1 has a thousandth plane 3 and a second plane 4 having a higher height than the first plane 3. A protrusion 5 having a width that decreases upward is provided between the first plane 3 and the second thousandth plane 4. The upper surface 6 of the protrusion 5 is formed into a concave shape corresponding to the outer shape of the O-ring 7 as a ring-shaped member. An O-ring 7 as a ring-shaped member is placed on the upper surface 6 of such a projection 5. Since the outer shape of the 0 ring 7 and the upper surface 6 of the protrusion 5 are completely different, the 0
The ring 7 moves the third mold 8 onto the zero-order lower mold 1 that is stably placed on the protrusion 5 . This arrangement allows the second
The side wall 9 of the mold 2, the side wall lO1 of the third mold 8, and the first plane 3 and second plane 4 of the lower mold 1 form a molding cavity 11 having a shape corresponding to the cross section of the molded product. The rubber-like elastic material 13r forming the packing body 12 in the molding cavity 11 is arranged so that the O-link 7 and the tip 14 of the rubber-like elastic material 13 are in contact with each other (see FIG. 1(b)). Next, the upper mold 15 is closed and the rubber-like elastic material 13 is heated and pressurized. The rubber-like elastic material 13 is fluidized by heating, flows from above, and flows downward so as to wrap around the O-ring 7 placed on the protrusion 5. At this time, the recess 7a
is formed.

The rubber-like elastic material 13 that has flowed downward is formed by a space 15a formed by the first plane 3 and the side wall 10 of the third mold 8, and a space 15a formed by the second plane 4 and the side wall 9 of the second mold 2. Blank space 16
and fills the entire molding cavity (see FIG. 1(C)).

In this manner, the rubber-like elastic material 13 is vulcanized and molded, and after the rubber-like elastic material 13 has hardened, the mold is opened and the molded product 17 is taken out (see FIG. 1 (b)).

In this way, the O-ring 7 is connected to the sulfurized H
>Inside, since it is incorporated into the packing body 12, the step of later assembling the O-ring into the packing body can be omitted, and the rubber-like elastic material 13 is filled to the back side of the O-ring, so the O-ring can be securely attached to the packing. Can be fitted.

FIG. 2 shows a second embodiment of the packing manufacturing method according to the present invention. In FIG. A guide pin 18 extending from the lower die l is implanted along. The guide pin 18 has a length longer than the height of the protrusion 5, and has a length that is approximately the same as the height of the apex of the O-ring 7 when the O-ring 7 is placed on the protrusion 5. The guide pins 18 are made up of a pair of opposing guide pins 18, and are arranged at several locations within the cavity of the lower mold 1. Furthermore, the width between the pair of guide pins 18 is approximately equal to the diameter of the O-ring 7.
The packing body 12 is vulcanized and molded as described in the embodiment. In the first embodiment, when the rubber-like elastic material 13 is pressurized, only a downward force is applied to the O-ring 7, so the Q-IJ ring 7 is supported on the upper surface 6 of the protrusion 5.
Although no positional deviation occurs, if the positional deviation of the Q17 ring 7 occurs due to other factors such as when the O-ring 7 used is a large-diameter product, the above-mentioned guide pin 18 will prevent the positional deviation of the O-ring 7. can be effectively prevented.

Next, FIGS. 3(a) and 3(b) show a third embodiment of the packing manufacturing method according to the present invention. According to this embodiment, the upper surface 19 of the projection 5 has a convex shape, It has the same cross-sectional shape as the groove of the packing body 12.

On the other hand, instead of the O-ring 7 used in the first and second embodiments, a ring body 20 having a U-shaped cross section and an inner shape corresponding to the cross-sectional shape of the projection 5 is attached to the projection 5. Place it so that it covers it. Using the ring body 20 having such a configuration, the packing body 12 is vulcanized and molded in a mold in the same manner as in the first and second embodiments. At this time, since the ring body 20 is securely fixed to the protrusion 5, no displacement occurs due to the pressure applied inside the molding cavity 11, so the packing can be molded without using the guide pin 18. . Ring body 20 is 0
It is an alternative to ring 7 and performs the same function.

Note that although rubber is used for the O-ring 7 and the ring body 2o, special packings having other characteristics can also be manufactured by using materials other than rubber.

(Effects of the Invention) According to the packing manufacturing method of the present invention, the step of arranging a ring-shaped member in a mold, and the step of arranging a ring-shaped member in a mold during vulcanization molding of a packing main body, Since the process of assembling the O-ring into the packing body after vulcanization molding of the packing body is omitted, production efficiency can be improved, and the O-ring can be twisted and attached to the packing body while retaining stress. Since the back side of the O-ring is filled with a rubber-like elastic material, the O-ring is securely fitted into the packing and the O-ring is not inserted after molding.
The 17 ring does not come off, and when changing the size of the O-ring fitted to the packing, there is no need to change the mold, improving work efficiency.

[Brief explanation of the drawing]

FIGS. 1(a), (b), (c), and (6) are longitudinal cross-sectional views of a mold representing a first embodiment of the packing manufacturing method of the present invention, and FIG. FIGS. 3(a) and 3(b) are longitudinal sectional views showing a third embodiment of the packing manufacturing method of the present invention;
FIG. 4 is a longitudinal sectional view of a packing according to the prior art. Explanation of symbols l...Lower mold 2...Second mold 3...
First plane 4... Second plane 5... Protrusion 6... Top surface 7... 0 ring
8...Third mold 13...Rubber-like elastic material 15
...Upper mold 17...Molded product 18...Guide pin 20...Ring body Figure 2! Figure 3 (o)
(b) 1st (a an (C) 5a

Claims (1)

[Claims] (1) A method for manufacturing a packing having a recess in the center of the main body and a ring-shaped member fitted into the recess, comprising the steps of arranging the ring-shaped member in a mold, and the packing main body. A method for manufacturing a packing comprising the step of incorporating a ring-shaped member placed in a mold into the packing body during vulcanization molding.