JPH0246371A - Manufacture of sealing device and mold therefor - Google Patents

Abstract

PURPOSE:To simplify the machining process, improve productivity, and reduce the production cost by rolling a screw groove on a resin seal lip by the molding pressure concurrently with the vulcanization molding of the first seal ring. CONSTITUTION:The recessed section 24 of an opened lower mold, a backup ring 4 and a resin raw material B are stacked and arranged in sequence, the periphery of the bent section B1 of the resin raw material B is held in contact with the outer periphery of a core bar mold 27 serving as the wall face of the inner diameter side of the recessed section 24 of the lower mold. A rubber substrate is arranged and molded and heated and pressurized. The bent section B1 of the resin raw material B softened by heat is pressed to the surface of the core bar mold 27 by the pressure of the fluid rubber substrate, the shape of a screw groove 28 notched on the surface of the core bar mold 27 is printed on the inner periphery of the bent section B1. The excess portion extended at the tip of a molded seal lip taken out when the mold is opened after the vulcanization molding is completed to complete a sealing device.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a sealing device that seals between two relatively rotating members, and a mold thereof.

(Prior Art) Conventionally, there is a sealing device of this type as shown in FIG. 6, for example. That is, the sealing device 100 includes a first seal ring 102 having a seal lip 101 made of a rubber-like elastic body, and a second seal ring 104 having a resin seal lip 103 that backs up the side surface of the seal lip 101 on the atmosphere side. We are prepared. By backing up the seal lip 101 made of rubber-like elastic material with the seal lip 103 made of resin in this manner, the pressure resistance is increased, and the seal lip 101 is used in seals that require pressure resistance such as compressors and pumps.

In such a sealing device 100, a first seal ring 102 having a seal lip 101 made of rubber-like elastic material and a second seal ring 104 having a seal lip 103 made of resin are separately molded, and each seal ring 102, 104 were manufactured by combining them together.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, there are cases where it is desired to improve the sealing performance by threading the resin seal lip 103. In the case of such thread processing, conventionally, the thread is formed by cutting using a lathe or the like, or by plastic processing such as rolling, but this increases the number of processing steps for the resin seal lip 103. There was a problem that production costs increased.

The present invention has been made to solve the problems of the prior art described above, and its purpose is to develop a sealing device that can simplify the thread processing process, improve productivity, and reduce production costs. The object of the present invention is to provide a manufacturing method and a mold for the same.

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a first seal ring having a seal lip made of a rubber-like elastic body is vulcanized and molded, and the first seal ring is , in a manufacturing method of a sealing device in which a second seal ring having a rolled thread groove is assembled to a resin seal lip, the resin seal is simultaneously vulcanized and molded by molding pressure during vulcanization molding. It is characterized by rolling a thread groove on the lip.

Furthermore, the mold for the sealing device of the present invention includes a lower mold having an annular recess into which a washer-shaped resin material whose inner diameter side is bent into a cylindrical shape in the axial direction is inserted; an upper mold having an annular protrusion that is inserted to form an annular cavity between the inner peripheral surface of the recess, and an inner peripheral surface of the bent portion of the resin material of the inner peripheral surface of the recess of the lower mold; It is characterized by having a threaded groove carved in the part where it comes into contact.

(Function) According to the manufacturing method of the sealing device having the above configuration, the thread groove is formed in the resin seal lip at the same time as the first seal ring is vulcanized and molded, and the thread groove machining process is performed.

When using the above-mentioned mold, the mold is closed after the resin material is set, and a dough made of a rubber-like elastic material is filled into the cavity and heated and pressurized.

Then, the bent portion of the resin material softened by the heat is pressed against the threaded groove on the inner periphery of the recess, forming a threaded groove on the inner periphery of the bent portion.

(Example) The present invention will be explained below based on the illustrated example. 1st
The figure shows a sealing device manufactured by the manufacturing method of the present invention.

That is, l indicates the entire sealing device, including the first seal ring 2 made of rubber-like elastic material on the side of the sealed fluid, and the first seal ring 2 made of PTFE (
It is constructed by combining a second seal ring 3 made of (tetrafluoroethylene resin) and a backup ring 4 made of metal, and the second seal ring 3 is held between the first seal ring 2 and the backup ring 4. has been done. That is, the first seal ring 2 is fitted onto the inner periphery of a housing (not shown). An outer cylinder part 5, an annular support part 6 extending radially inward from the middle part of the outer cylinder part 5, and a lip tip 7 extending from the support part 6 toward the sealed fluid side F in sealing contact with the shaft surface. It consists of a sealing lip 8 forming a sealing part.

The first seal ring 2 and the backup ring 4 are integrally baked and assembled. The backup ring 4 has an L-shaped cross section and is embedded in the outer cylinder part 5 of the first seal ring 2 to serve as a core metal of the outer cylinder part 5. The backup ring 4 has a cylindrical part 9 which is embedded in the outer cylinder part 5 of the first seal ring 2 and also serves as a core bar of the outer cylinder part 5. Flange portion 10 extending radially inward
It is composed of. The second seal ring 3 is held between the flange portion 10 and the support portion 6 of the first seal ring 2.

The second seal ring 3 is a plate-shaped member molded from a resin material such as PTFE, and its inner diameter side is bent into a cylindrical shape toward the sealed fluid side to form a resin seal lip 11. The lip tip of this resin seal lip 11 extends to the lip tip of the seal lip 8 of the first seal ring 2.
It is designed to support the force applied to the

A threaded groove 12 is formed on the sealing sliding surface of this seal lip 11 made of resin. The thread groove 12 is the seal lip 11
It is formed over approximately the entire length in the axial direction.

A plurality of fixing holes 13 are provided at the contact portion between the second seal ring 3 and the back amplifier ring 4, that is, at the flange portion IO of the backup ring 4 to prevent the second seal ring 3 from rotating. . That is, the hole 13 is
A plurality of them are provided in the center of the flange portion 10 of the backup ring 4 at predetermined intervals in the circumferential direction. The backup ring 4 is inserted into this hole 13 during vulcanization molding.

Next, a method for manufacturing the sealing device having the above configuration will be explained.

The sealing device 1 is molded using a mold 20 shown in FIG. The mold 20 is generally composed of a lower mold 22 and an upper mold 23.

The upper surface of the lower mold 22 is provided with an annular recess 24 into which a washer-shaped resin material B whose inner diameter side is bent in the axial direction is inserted. The recess 24 has a generally rectangular cross section with an open upper part. The lower mold 22 includes a first mold 25 that forms the bottom surface of the recess 24 and a second mold 25 that forms the outer diameter side wall surface of the recess 24.
A mold 26 and a core ring mold 27 forming the inner diameter side wall surface of the recess 24
It has a divided configuration.

A thread groove 28 is formed on the outer circumferential surface of the 8-rod mold 27 that forms the inner wall surface of the recess 24 .

The inner periphery of the bent portion B1 of the washer-shaped resin material B is brought into contact with the outer periphery of this 8-rod mold 27.

On the other hand, an annular protrusion 29 that is inserted into the recess 24 of the lower mold 22 is formed protruding from the lower surface of the upper mold 23 . When the mold is closed, an annular cavity 21 having an O-shaped cross section corresponding to the first seal ring 2 is defined between the protrusion 29 and the inner peripheral surface of the recess 24. Become.

Next, the sealing device is molded as follows.

First, before the first seal ring 2 is vulcanized and molded, a metal backup ring 4 and a washer-shaped resin material B that is to become the resin second seal ring 3 are molded in advance.

Then, the backup ring 4 and the resin material B are placed one on top of the other in order in the recess 24 of the opened lower mold 22 (
(See Figure 3). The inner circumference of the bent portion B1 of the resin material B is
The four parts 24 of the lower mold 22 are held in contact with the outer periphery of the core wire mold 27, which is the inner diameter side wall surface.

Furthermore, the rubber dough is placed, the mold is closed, and the mold is heated and pressurized.

Then, the bent portion B1 of the resin material B softened by heat
is pressed against the surface of the core ring mold 27 by the pressure of the fluidized rubber dough (see Fig. 4), and the shape of the helical groove 28 carved on the surface of the core ring mold 27 is copied onto the inner periphery of the bent portion B1. .

Furthermore, in this embodiment, since the hole 13 is provided in the flange portion 10 of the bank up ring 4, the resin material B
partially bites into the hole 13, and the resin material B and the backup ring 4 are firmly fixed.

After the vulcanization molding is completed, the molded product W is opened and taken out, and the excess portion W1 extending to the tip of the seal lip 8 is cut off as shown in FIG. 5, thereby completing the sealing device I.

In this way, since the thread groove 12 of the seal lip 8 is formed by pressing against the thread groove 28 of the mold 20 during vulcanization molding, the depth, shape, etc. of the thread groove 12 of the seal lip 8 can be formed accurately. The optimum groove shape can be selected.

(Effects of the Invention) The present invention has the above-described configuration and operation, and since the thread groove is rolled in the resin seal lip using the vulcanization molding pressure of the first seal ring, the resin seal The number of processes for machining the lip thread groove can be reduced, production efficiency can be increased, and machining costs can be reduced.

Further, according to the mold of the present invention, the pressure of the rubber-like elastic material fabric during vulcanization molding can be effectively applied to the resin material, and thread groove processing can be performed on the resin material with an extremely simple configuration. Can be done.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of essential parts showing an embodiment of a sealing device manufactured by the manufacturing method according to the present invention, FIG. 2 is a longitudinal cross-sectional view showing an embodiment of a mold for the sealing device of the present invention, 3 and 4 show an example of the manufacturing method of the sealing device shown in FIG. 1, in which FIG. 3 is a schematic vertical sectional view of the main part in the state before vulcanization molding with the mold opened, and FIG. 4 5 is a schematic vertical sectional view of the main part during vulcanization molding, FIG. 5 is a longitudinal sectional view of the main part of the molded product after vulcanization molding, and FIG. 6 is a longitudinal sectional view of the main part of a conventional sealing device. Explanation of symbols 1... Sealing device 2... First seal ring 3
... Second seal ring 8 ... Seal lip made of rubber-like elastic body 11 ... Seal lip made of resin 12 ... Thread groove 13 ... Hole 20 ... Molding mold 21 ... Cavity 22 ...・Bottom mold
23... Upper mold 24... Concavity 25.26... 1st degree 27... 8 Rod mold B... Resin material 2nd mold 28... Thread groove Fig. 1 Fig. 3 Fig. 4 figure

Claims (2)

[Claims] (1) Sealing by vulcanizing and molding a first seal ring having a seal lip made of a rubber-like elastic body, and assembling a second seal ring, which is a resin seal lip with thread grooves, to the first seal ring. A method for manufacturing a sealing device, characterized in that, simultaneously with the vulcanization molding of the first seal ring, a thread groove is rolled in the resin seal lip using the molding pressure of vulcanization molding. (2) A lower mold with an annular recess into which a washer-shaped resin material whose inner diameter side is bent axially into a cylindrical shape is inserted into the recess when the mold is closed, and the inner peripheral surface of the recess and an upper mold having an annular protrusion forming an annular cavity therebetween, and a threaded groove is provided in a portion of the inner circumferential surface of the recess of the lower mold that is in contact with the inner circumferential surface of the bent portion of the resin material. A mold characterized by engraving.