JP2649067B2 - Manufacturing method of sealing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a sealing device for sealing between two relatively rotating members, and a molding die thereof.

(Prior Art) Conventionally, as this type of sealing device, for example, there is one as shown in FIG. 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 for backing up the atmosphere side surface of the seal lip 101. Have. By backing up the seal lip 101 made of a rubber-like elastic material by the seal lip 103 made of resin as described above, the pressure resistance is increased, and the seal lip 101 is used for a seal portion such as a compressor or a pump which requires pressure resistance.

In such a sealing device 100, a first seal ring 102 having a rubber-like elastic seal lip 101 and a second seal ring 104 having a resin seal lip 103 are separately formed, and each of the seal rings 102, 104 is formed. It was manufactured by combining them together.

(Problems to be Solved by the Invention) Incidentally, in the above-described conventional technology, there is a case where it is desired to enhance the sealing performance by subjecting the resin sealing lip 103 to thread processing. In the case of performing such screw processing, conventionally, cutting processing using a lathe or the like, or plastic processing such as rolling is performed, but the processing step of the resin seal lip 103 increases accordingly, There was a problem that production cost increased.

The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to provide a sealing device capable of simplifying a threading process, improving productivity, and reducing production cost. It is to provide a manufacturing method.

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a cross section having a cylindrical portion and a flange portion extending radially inward from an atmospheric side end of the cylindrical portion. An L-shaped metal backup ring and a washer-shaped resin seal ring whose inner diameter is bent in a cylindrical shape in the axial direction are assembled, and the rubber-like elastic seal ring is vulcanized and molded as one unit. In the method of manufacturing the device, a thread groove is rolled into the lip portion of the resin seal ring by the pressure of the vulcanization molding at the same time as the vulcanization molding of the rubber-like elastic seal ring. It is characterized in that the resin seal ring is fixed by providing a hole and partially penetrating the resin seal ring into the hole.

(Operation) According to the manufacturing method of the sealing device having the above configuration, a screw groove is formed in the resin-made seal lip simultaneously with the vulcanization molding of the first seal ring, and the screw groove processing step is reduced.

In addition, since a hole is provided in the flange portion of the backup ring, the resin seal ring partially bites into the hole and is firmly fixed.

(Example) Hereinafter, the present invention will be described based on an illustrated example. FIG. 1 shows a sealing device manufactured by the manufacturing method of the present invention.

That is, reference numeral 1 denotes the entire sealing device, and a first sealing ring 2 made of a rubber-like elastic material on the sealing fluid side, a second sealing ring 3 made of PTFE (ethylene tetrafluoride resin), and a metal backup ring The second seal ring 3 is sandwiched between the first seal ring 2 and the backup ring 4. That is, the first seal ring 2 includes an outer cylindrical portion 5 fitted to the inner periphery of a housing (not shown), an annular support portion 6 extending radially inward from a middle portion of the outer cylindrical portion 5, Extending from the part 6 to the sealing fluid side F, the lip tip 7 consists of a sealing lip 8 in sealing contact with the shaft surface to form a seal.

The first seal ring 2 is assembled by baking integrally with the backup ring 4. The backup ring 4 has an L-shaped cross section and has a cylindrical portion 9 and a cylindrical portion 9 embedded in the outer cylindrical portion 5 of the first seal ring 2 as a core of the outer cylindrical portion 5.
Flange portion 10 extending inward in the radial direction from the atmosphere side end of
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-like member formed of a resin material such as PTFE, and has a resin-made sealing lip 11 whose inner diameter side is bent into a cylindrical shape toward the sealed fluid side.
The lip tip of the resin sealing lip 11 is
Of the seal lip 8 of the first seal ring 2 to support the force applied to the seal lip 8 of the first seal ring 2.

A thread groove is provided on the sealing sliding surface of this resin seal lip 11.
12 are formed. The screw groove 12 is formed over substantially the entire length of the seal lip 11 in the axial direction.

A plurality of fixing holes 13 for preventing the rotation of the second seal ring 3 are provided in a contact portion between the second seal ring 3 and the backup ring 4, that is, in a flange portion 10 of the backup ring 4. That is, a plurality of holes 13 are provided at predetermined intervals in the circumferential direction at the center of the flange portion 10 of the backup ring 4. The backup ring 4 bites into the hole 13 during vulcanization molding.

Next, a method of manufacturing the sealing device having the above configuration will be described.

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

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

A thread groove 28 is formed on the outer peripheral surface of the core bar 27 that forms the inner wall surface of the recess 24. A bent portion B1 of the washer-shaped resin material B is provided on the outer peripheral surface of the core rod type 27.
The inner circumference of the abutment comes into contact.

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

Next, molding of the sealing device is performed as follows.

First, before vulcanization molding of the first seal ring 2, a metal backup ring 4 and a resin second seal ring 3 are formed.
And a washer-shaped resin material B to be formed in advance.

Then, the backup ring 4 and the resin material B are arranged in order in the recess 24 of the opened lower mold 22 (see FIG. 3). The inner periphery of the bent portion B1 of the resin material B is held in a state of being in contact with the outer periphery of the core rod mold 27 which becomes the inner wall surface of the concave portion 24 of the lower mold 22.

Further, the rubber cloth is arranged, the mold is closed, and heating and pressing are performed. Then, the bent portion of the resin material B softened by heat
B1 is pressed against the surface of the core bar mold 27 by the pressure of the fluidized rubber material (see FIG. 4).
The shape of the screw groove 28 engraved on the surface of 27 is copied.

Further, in this embodiment, since the hole 13 is provided in the flange portion 10 of the backup ring 4, the resin material B partially penetrates into the hole 13 so that the resin material B and the backup ring 4 are firmly connected. Fixed to

After completion of the vulcanization molding, the surplus portion W1 extending to the tip of the seal lip 8 of the molded product W taken out by opening the mold is cut as shown in FIG. 5, and the sealing device 1 is completed.

As described above, since the screw groove 12 of the seal lip 8 is formed by pressing against the screw groove 28 of the molding die 20 at the time of vulcanization molding, the depth, shape, and the like of the screw groove 12 of the seal lip 8 can be accurately formed. It is possible to select an optimum groove shape.

(Effects of the Invention) The present invention has the above-described configuration and operation.
Since the thread groove is rolled into the resin seal lip using the vulcanization pressure of the seal ring, the number of screw groove processing steps for the resin seal lip can be reduced, and the production efficiency is increased. Processing cost can be reduced.

Further, according to the manufacturing method of the sealing device of the present invention, the pressure of the rubber-like elastic material at the time of vulcanization molding can be effectively applied to the resin material, and the resin material is applied to the backup ring with a very simple configuration. It can be fixed, and thread groove processing can be performed on the resin material.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an essential part showing an embodiment of a sealing device manufactured by the manufacturing method according to the present invention, and FIG. 2 shows an embodiment of a molding die used in the manufacturing method of the sealing device of the present invention. FIGS. 3 and 4 show one embodiment of a method for manufacturing the sealing device of FIG. 1, and FIG. 3 is a schematic longitudinal sectional view of a main part in an unopened state before vulcanization molding. Fig. 4, Fig. 4 is a schematic longitudinal sectional view of main parts during vulcanization molding, Fig. 5 is a longitudinal sectional view of main parts of a molded product after vulcanization molding, and Fig. 6 is a longitudinal sectional view of main parts of a conventional sealing device. It is. DESCRIPTION OF SYMBOLS 1 ... Sealing device 2 ... First seal ring 3 ... Second seal ring 8 ... Seal lip made of rubber-like elastic material 11 ... Seal lip made of resin 12 ... Screw groove, 13 ... Hole 20: Mold, 21: Cavity 22: Lower mold, 23: Upper mold 24: Recess 25, 26 ... First and second molds 27: Core rod type, 28: Screw groove B ... … Resin material

Claims (1)

(57) [Claims] 1. A metal backup ring having a substantially L-shaped cross section, comprising: a cylindrical portion; and a flange portion extending radially inward from an end of the cylindrical portion on the atmosphere side; A method for manufacturing a sealing device in which a bent washer-shaped resin seal ring and a rubber-like elastic seal ring are integrally formed by vulcanizing the rubber-like elastic seal ring. At the same time, a thread groove is formed on the lip portion of the resin seal ring by the pressure of the vulcanization molding, and a plurality of holes are provided in the flange portion of the backup ring, and the resin seal ring is partially A method for manufacturing a sealing device, characterized in that the resin seal ring is fixed by being cut into a sealing ring.