JPH03205116A - Production of oil seal fitted with diaphragm - Google Patents

Abstract

PURPOSE:To inhibit extrusion of the material for forming oil seal by placing a material piece for molding a diaphragm part on the outer part of a reinforcing ring and furthermore superposing a second mold wherein a supporting projection is provided to the top face of a cavity opposed to the end edge in the opposite side of the flange of the reinforcing ring. CONSTITUTION:The flange 6 of a reinforcing ring 5 is externally fitted to an annular projection 12 provided to the central part of a first forming mold 10. A material piece for molding an oil seal part is placed on the inner part of the reinforcing ring 5. Then a material piece for molding a diaphragm part is placed on the outer part of the reinforcing ring 5. A second forming mold 11 is superposed wherein a supporting projection 20 is provided to the top face 17 of a cavity opposed to the end edge 7 in the opposite side of the flange 6 of the reinforcing ring 5. Thereafter the first and second forming molds 10, 11 are heated and pressurized and both the oil seal part 1 and the diaphragm part 3 are vulcanized and molded and also bonded to the reinforcing ring 5. Thereby the required oil seal fitted with the diaphragm is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for hitting an oil seal with a diaphragm used as a sealing means for a mechanical device with a rotating shaft that suffers from center runout. (For example, an oil seal with a diaphragm is used as a sealing means for a shaft that rotates with center runout relative to a housing, such as a rotating shaft in a washing machine. The oil seal shown in the figure has an oil seal part 1 with a seal lip 2 that slides on the surface of a rotating shaft, and a flexible membrane part, and the outer srs is installed in the housing of a mechanical device. A reinforcing ring 5 having a substantially cylindrical shape and having a flange 6 attached to one end is interposed between the diaphragm part 3 and is bonded to the oil seal part 1 and the diaphragm part 3. A push 9 is inserted on the side, which is made of a low-friction Hewei resin material and is inserted around the rotating shaft to maintain the concentricity of the oil seal part 1 with respect to the rotating shaft.Oil seal part 1 The molding material for the diaphragm portion 3 is selected from the viewpoint of wear resistance, and the molding material for the diaphragm portion 3 is selected from the viewpoints of weather resistance and bending resistance, and the two materials usually have different compositions. A certain shape of the attached oil seal is made using the mold shown in Fig. 4 and Fig. 5.
This is done as shown in the figure. (Refer to Japanese Patent Publication No. 52-48259) That is, as shown in FIG. 4, a first mold 1 is combined with a second mold 11 to form a mold cavity corresponding to the shape of an oil seal with a diaphragm.
The flange G side of the reinforcing ring 5 is attached to the annular protrusion 12 which is provided in the center of the oil seal with a diaphragm and has a shape corresponding to the annular space formed between the back of the seal lip 2 of the oil seal with a diaphragm and the reinforcing ring 5. At the same time, a piece of material l4 for forming the oil seal part is placed inside the annular protrusion l2, a piece of material 15 for forming the diaphragm part is placed on a certain surface of the diaphragm part,
Each. aiiL. Next. The first mold lO and the second mold ll are pressurized and heated to mold and vulcanize the oil seal part 1 and diaphragm part 3, and also to bond them to the reinforcing ring 5. (Problems to be Solved by the Invention) In the process of molding and vulcanizing the rubber portion 1.3 and adhering it to the reinforcing ring 5 as described above. A certain form 11 in Figure 4!
During the transition from the prepared state to the final pressurized state shown in Fig. 5, the process shown in Fig. 6 is passed through. In the intermediate process shown in the figure, the molding cavity sandwiched between the reinforcing ring 5 and the oil seal part or surface of the second mold 11 is filled with the material for shaping the oil seal part, and then the material for shaping the oil seal part is filled. During the transition from the intermediate stage shown in the figure to the final pressurized state shown in FIG. It enters between the bottom surfaces 16 and pushes up the reinforcing ring 5 toward the second mold ll side, bringing the opposite edge 7 into close contact with the cavity top surface 17 of the second mold 11 facing the Q edge 7. Therefore, the remaining material for forming the oil seal part is pushed out through the fitting gap between the reinforcing ring 5 and the annular protrusion 12, and the surface part of the diaphragm part that is immersed in the sealing liquid when installed in the actual machine. (Indicated by the symbol A in Figure 3.) The protrusion into the 2A section causes the following problems. ■ Separation occurs between the oil seal molding material and the diaphragm molding material, leading to destruction. ■ Water, etc. that entered from the joint between both materials causes rust to occur in the reinforcing ring 5, and this rust causes a. Push 9 by lowering the holding force for push 9
This results in the dropout of the parts. b. This causes the push 9 and the seal rib 2 to become out of alignment.

C. This causes the adhesive between the reinforcing ring 5 and the rubber part to peel off, resulting in destruction. This causes problems such as: In view of the problems associated with the above-mentioned conventional method, the present invention proposes a method that can prevent the oil seal material from protruding from the surface portion A on the flange side. (Means for Solving the Problems) The present invention takes into account the problems in the method of manufacturing an oil seal with a diaphragm according to the above-described conventional technology, and provides an annular projection provided at the center of the first oval mold. Fit the reinforcing ring flange on the outside. A piece of material for molding the oil seal part is placed inside the reinforcing ring, and a piece of material for forming the diaphragm part is placed on the outside of the reinforcing ring. A second mold having a support protrusion is placed on the top surface of the cavity, and the first and second molds are heated and heated.
Apply pressure to vulcanize the oil seal and diaphragm.
It is designed to be molded and glued to the reinforcing ring. (Function) ] In the method for manufacturing an oil seal with a diaphragm of the present invention having the structure described above, the protrusion provided on the top surface of the second pre-shaped cavity is located on the opposite side of the flange of the reinforcing ring. A gap is formed between the top surface of the cavity and the edge of the reinforcing ring by supporting the edge, and the excess material for forming the oil seal part flows out of the reinforcing ring, so that it is located on the atmosphere side when installed on the actual machine. Glue it to the outer circumferential surface of the reinforcing ring. (Example) In the example shown in FIG. The molding cavity of the second mold 11 facing the edge 7 on the opposite side to the flange 6 of the reinforcing ring 5 inserted into the annular protrusion 12 in the center of the first mold 10 functions normally over a long period of time. can be sustained.

[Brief explanation of drawings]

Figure 1 is. A sectional view of the precept type used in the present invention, FIG. 2 is a partial view taken from the position indicated by the arrows 1 and 2 in FIG. 1, and FIG. The cross-sectional views of the products shown in FIGS. 4, 5, and 6 show certain preparation steps of the conventional manufacturing method, respectively. FIG. 3 is a cross-sectional view showing the situation in the Et final process and intermediate process.

Claims (1)

[Claims] 1. Approximately in the middle of the oil seal part (1) having a seal lip (2) that slides on the circumferential surface of the shaft and the diaphragm part (3) having a flexible membrane part and fixing the outer circumferential part, Reinforcement ring (5) with cylindrical shape and a flange (6)
In the method for manufacturing an oil seal with a diaphragm embedded therein, the flange (6) of the reinforcing ring (5) is fitted onto an annular projection (12) provided at the center of the first mold (10), A piece of material for forming an oil seal portion (14) is placed inside the reinforcing ring (5), and the reinforcing ring (5) is placed inside the reinforcing ring (5).
A piece of material for forming a diaphragm (15) is placed on the outside of the cavity top surface (17) facing the edge (7) of the reinforcing ring (5) on the opposite side of the flange (6). A second mold (11) provided with a support protrusion (20) is placed on top of the second mold (11),
The oil seal portion (1) and the diaphragm portion (3) are heated and molded by heating and pressurizing the first and second molding molds (10, 11), and the diaphragm is bonded to the reinforcing ring (5). Manufacturing method for oil seals.