JPH0363935B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing an oil seal related to shaft seal technology.

[Conventional technology]

Conventionally, as a type of oil seal, as shown in FIG. 3, a metal reinforcing ring a having a substantially L-shaped cross section has an outer circumferential axial portion b and an inner circumferential free end of an inner radial portion c. It is known that seal members d and e made of rubber-like elastic material are vulcanized and bonded to the rubber-like elastic material. This type of oil seal is inserted into the inner periphery of the shaft hole of various rotating equipment, for example, and seals out various fluids by sliding the seal lip-shaped inner peripheral seal member e with the rotating shaft of the equipment. Different materials suitable for their respective functions are selected and used for the inner circumferential seal member e, which is responsible for the dynamic seal portion, and the outer circumferential seal member d, which is responsible for the static seal portion, and are mainly made using compression molding equipment. It is mass produced.

[Problem that the invention seeks to solve]

However, according to this conventional manufacturing method, the above two
It is difficult to control the shape and weight of the molding materials (dough) for types d and e, and if there are variations in the dough filling operation, there is a risk that the doughs will mix with each other in the cavity.

In view of this problem, the present invention aims to provide a manufacturing method for molding a highly accurate oil seal product by preventing mixing of both materials, which become different materials.

[Means for solving problems]

In order to achieve this objective, the method for producing an oil seal of the present invention includes a split mold in which an upper mold, a lower mold, and a middle mold are added as needed to form a cavity in the center, and a mold that holds the divided mold in between. The upper and lower heating plates to be tightened, and the holes formed in the heating plates and the lower die of the split mold.
upper and lower piston members are fitted to be movable in the vertical direction and face each other while sandwiching the upper mold, and an oil seal is reinforced within the cavity on opposing surfaces of the upper mold and lower mold of the split mold. A clamping annular protrusion for clamping the ring is provided, and the upper and lower spaces formed between the upper mold and both piston members are provided at required locations on the split mold, respectively. A molding device is used which is provided with a material passage that communicates with the outer circumferential portion and the inner circumferential portion of the cavity, which are separated by the clamping of the reinforcing ring by the clamping annular protrusion.

[Effect]

The above manufacturing method utilizes a transfer molding method in place of the conventional compression molding method, that is, the cavity is divided into an outer peripheral portion and an inner peripheral portion by clamping the reinforcing ring of the oil seal by the clamping annular protrusion. While dividing, the sealing member forming dough placed in the upper and lower spaces is fed to the outer and inner circumferential portions of the cavity through the material passage by the operation of a piston member having the hole as a cylinder portion.

〔Example〕

Next, an embodiment of the present invention will be described, focusing on the configuration of a molding apparatus used for carrying out the embodiment.

In FIGS. 1 and 2, reference numeral 1 is a split mold consisting of an upper mold 2, a middle mold 3, and a lower mold 4,
The mold is placed on a fixed heating platen 5, and the mold is opened and closed as the movable heating platen 6 moves up and down. Approximately in the center of this split mold 1, a cavity 7 is provided, in which the outer peripheral surface is formed by a middle mold 3, the lower surface is shared by a lower mold 4, the upper surface and inner peripheral surface are shared by an upper mold 2, and the lower surface of the upper mold 2 and the lower mold 4, integrally projecting annular projections 8 and 9 opposing each other and gripping the radial portion of the reinforcing ring a of the oil seal. It comes to be divided into an inner peripheral portion 11. The upper and lower heating plates 5, 6 and the lower die 5 are provided with holes 12, 13, 14 that are concentric with each other.
The upper and lower piston members 15 and 16 are fitted airtightly and slidably in the vertical direction. 17 is a balance rod. Both piston members 15 and 16 are
It is connected to a drive source (not shown) and moves up and down relative to the movable hot platen 5 and the lower die 4, thereby increasing or decreasing the volume of the annular spaces 18, 19 formed above and below the upper die 2. A sprue 20 is formed in the upper mold 2 to communicate the upper annular space 18 with the outer peripheral portion 10 of the cavity 7, and between the upper mold 2 and the lower mold 4, the lower annular space 19 and the inner part of the cavity 7 are connected. A passage 21 communicating with the circumferential portion 11 is formed.

The procedure for manufacturing an oil seal using the molding apparatus configured as described above and the operation of the apparatus are as follows.

Lift the movable hot platen 6 to open the split mold 1, and move the piston member 15 upward and the piston member 16 downward, respectively, and open the lower mold 4.
The reinforcing ring a of the oil seal is inserted into the clamping annular protrusion 9 formed in , and the seal member molding dough e prepared in advance is inserted into the lower annular space 19 , and the split mold 1 is combined with the upper mold 2 . A reinforcing ring a is held between the holding annular protrusions 8 and 9 of the lower mold 4, and the sealing member forming dough d prepared in advance is placed on the upper mold 2 and the mold is clamped (FIG. 1). At this time, as described above, the cavity 7 has an outer circumferential portion 10 that communicates with the upper annular space 18 via the sprue 20 and an inner circumferential portion 1 that communicates with the lower annular space 19 via the passage 21.
It is divided into 1.

The dough d', e' is heated by the upper and lower heating plates 5, 6, and when the dough d', e' changes to a fluid state, the upper and lower piston members 15, 16 are pushed forward, and the sprue 20 and the passage 21 are heated. through the fabric d′,
e′ is the outer circumference and inner circumference portion 10 of the cavity 7,
11, wait for the adhesion of both fabrics d' and e' to the reinforcing ring a and cross-linking curing, and then open the mold.

〔Effect of the invention〕

As explained above, in the manufacturing method of the present invention, a piston cylinder mechanism is combined with a split mold to form two sets of upper and lower transfer molding parts, and an oil seal is attached to a set of annular holding projections formed on the inner wall of the cavity. A reinforcing ring is held between the reinforcing rings, thereby allowing the transfer molded part to communicate with the cavity divided into inner and outer peripheries,
There is no room for the seal member molding dough made of different materials to mix with each other, making it possible to mold high-precision oil seal products, as well as making it possible to extremely simplify the configuration of the molding equipment used to carry out the molding. It has the following.

[Brief explanation of drawings]

FIGS. 1 and 2 are half-cut cross-sectional views showing the operating state of a molding device used for carrying out a manufacturing method according to an embodiment of the present invention, and FIG. 3 is a half-cut sectional view of an oil seal manufactured by the same method. FIG. 1...Divided type, 2...Upper type, 3...Medium type, 4...
...Lower mold, 5, 6...Heating plate, 7...Cavity,
8, 9... Annular projection for clamping, 10... Outer peripheral portion,
11... Inner circumferential portion, 12, 13, 14... Hole, 1
5, 16... Piston member, 18, 19... Annular space, 20... Sprue, 21... Passage, a... Reinforcement ring, d', e'... Seal member forming dough.

Claims (1)

[Claims] 1 A split mold which is combined with an upper mold and a lower mold by adding a middle mold as necessary to form a cavity in the center, upper and lower heating plates that clamp and clamp the divided molds, and a combination of the heating plate and the split mold. Upper and lower piston members are fitted in a hole formed in the lower mold so as to be movable in the vertical direction and face each other while sandwiching the upper mold, and the cavity is provided on the opposing surfaces of the upper mold and lower mold of the split mold. A clamping annular protrusion for clamping the reinforcing ring of the oil seal is provided within the split mold, and a clamping annular protrusion is provided at a required location of the split mold to each of the upper and lower spaces formed between the upper mold and both piston members and the clamping annular protrusion. A method for manufacturing an oil seal, characterized in that the oil seal is manufactured using a molding device provided with a material passageway that communicates an outer peripheral portion and an inner peripheral portion of the cavity separated by the reinforcing ring.