JPS58222814A - Method and apparatus for preparing oil seal - Google Patents

Abstract

PURPOSE:To obtain an oil seal excellent in sealing peroperty, durability, etc. by a method wherein a material with directivity is mixed in advance with elastic base substance and injection-molded into a cavity provided in an injection molding die through a plurality of spiral injection passages. CONSTITUTION:An oil seal molding cavity 26 is provided between a fixed die 22 and a movable die 24 and an elastic base substance storing portion 28 is installed in part of the movable die 24. Elastic base substance 34 (such as rubber, synthetic resin material) with which material with directivity is mixed in advance is put into the elastic base substance storing portion 28, the pusher 32 is pushed down and the elastic base substnace 34 is injected from a plurality of spiral injection passages 30 equipped at the bottom of the storing portion 28 into the cavity 26. Thereby, the material with directivity is oriented in a fixed direction at a preset inclination angle to the central axis direction to obtain the oil seal to cause the counterflow phenonenon which checks oil leakage on the seal surface.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an oil seal used for a rotating shaft, and more particularly to a novel method and apparatus for manufacturing an improved oil seal.

Generally, as this type of oil seal, one constructed using an elastic material such as rubber or synthetic resin is known. Conventionally, oil seals have been made of a rubber annular body with a seal lip that comes into close contact with the outer circumferential surface of the rotating shaft.A garter spring is appropriately attached to the outer circumference of the seal lip to hold the seal lip in pressure contact with the rotating shaft. configured to do so. However, oil seals applied to high-speed rotating shafts have the disadvantage that as the seal lip wears, the sealing function decreases, eventually causing oil leakage.

From this point of view, in the past, multiple spiral protrusions were provided on the seal surface of the seal lip to form a threaded groove surface, which caused slight wear on the contact surface of the seal lip with the rotating shaft, thereby preventing oil leakage. A structure has been proposed and implemented in which, even if leaked oil occurs, the threaded surface of the seal lip and the rotation of the rotary shaft exert an axial flow pumping action to push the leaked oil back toward the oil side. °However, oil seals configured in this way have a complex structure, which not only makes machining difficult, but also increases the number of defects on the thread groove surface during molding, increasing manufacturing costs. In those applied to high-speed rotating shafts, there is a limit to the durability of the sealing effect, and the sealing effect was not satisfactory.

In addition, as a means to improve the durability of the sealing effect as described above, a technique has been proposed in which multiple layers of different materials are formed in the structure of the seal lip, but this technique has drawbacks in terms of processing technology and sealing performance.

Therefore, as a result of various studies in order to overcome all the problems of the conventional oil seals mentioned above, the inventor of the present invention mixed a directional substance into the rubber or synthetic resin material that is the base material of the oil seal. By arranging these directional substances in a certain direction on the seal surface at a required angle with respect to the axial direction of the rotating shaft, it is possible to create a backflow phenomenon against oil leakage on the seal surface and improve seal function and durability. Successfully developed an oil seal.

However, in order to obtain this type of oil seal, a simple and economical manufacturing technique is required to mix directional substances into the base material of the oil seal and to orient these directional substances in a predetermined direction. Ru. Therefore, as a result of extensive research, the inventor of the present invention discovered that when forming an oil seal of a predetermined shape by directly injecting a base material such as rubber into a mold, a unit material of a directional substance is added to the base raw material in advance. If the directional substance is mixed in, when the base material is injected into the mold, the directional substance will be contained in the base material in a state in which they are lined up in a certain direction. It has been found that by spirally injecting from one end side, it is possible to easily mass-produce the oil seal with the above-mentioned new configuration.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for manufacturing an oil seal having a novel configuration capable of improving sealing function and durability, which can be easily and economically mass-produced, and an apparatus for implementing this method. is to provide.

In order to achieve the above object, in the present invention, a directional substance is mixed in advance into an elastic base material, and the directional substance is introduced into an oil seal-shaped cavity provided in an injection mold through a plurality of spiral injection passages. It is characterized by injection molding.

In the method for manufacturing the oil seal, rubber or synthetic resin material can be suitably used as the elastic base material.

The directional substance is preferably selected from fibers such as glass fibers, carbon fibers, and heat-resistant synthetic fibers, or directional fine particles such as mica, graphite, talc, and silica.

On the other hand, when carrying out the method for manufacturing the oil seal,
The movable mold is equipped with a fixed mold and a movable mold that form an oil seal molding cavity of a predetermined shape, and a material storage section is provided in the movable mold located above the cavity, and the bottom of the material storage section of the movable mold and the movable mold are provided. If a manufacturing apparatus is used that includes an injection molding machine in which a plurality of spirally formed injection passages are provided and communicated with the upper end of the cavity, and a suppressor is disposed opposite to the material storage part of the movable mold. suitable.

Next, the method for manufacturing an oil cooler according to the present invention will be described in detail with reference to the accompanying drawings in relation to the apparatus for implementing this method.

FIG. 7 is a sectional view showing the basic structure of an oil seal manufactured by the manufacturing method of the present invention. That is, in FIG. 1, the oil seal includes an annular body IO made of an elastic material such as rubber, and a rotating shaft 7 is attached to a part of this annular body 10.
．． A seal lip l≠ is provided to form a sealing surface with 2, and a garter spring/l is attached to the outer periphery of the seal lip l≠ as necessary, and a part of the annular body 10 is attached to a metal cylinder. It consists of the configuration held in itr. Moreover, the annular body/θ having a seal lip/hole forming a sealing surface with the rotating shaft 1 is made to contain a directional substance 2Q so as to lie on the sealing surface and be inclined in a certain direction with respect to the axial direction. It is characterized by: In addition, as the directional substance j (7) that can be used in this case, fibers such as glass fiber, carbon fiber, and heat-resistant synthetic fiber, or fine particles having directional properties such as mica, graphite, talc, and silica are suitable.

Therefore, in the present invention, the oil seal having the above-mentioned structure is manufactured by the following means.

FIG. 2 shows an embodiment of an oil seal manufacturing apparatus that implements the method of the present invention. That is, in FIG. 2, reference numeral 2.2 indicates a fixed mold, and ≠ indicates a movable mold, and an oil seal molding cavity roller is provided between the fixed mold here and the movable mold λ. . For this cavity B, a material storage section 2t such as rubber or synthetic resin material is provided in a part of the movable mold λ≠.

However, in the movable mold provided with the material storage section 2t, 2≠
The fixed mold, the cavity formed between the two, and the two
A plurality of spiral injection passages 30 are bored at the upper end of J at predetermined distances in the circumferential direction and communicate with the bottom of the material storage section 2t (see FIGS. 3 and V). In this case, it is preferable to set the inclination angle θ of each injection passage 3θ with respect to the horizontal plane, for example, in the range of 2θ to /406 (
No. ≠ Figure reference fish). On the other hand, the movable mold 24 configured in this way
t, a suppressor 3λ for pushing out the base material thrown into the material storage part λl is placed.

Next, a case will be described in which an oil seal is manufactured using the injection molding machine configured as described above. First, after setting the movable mold 2≠ to the two fixed molds as shown in Fig. 2, the material storage part of the movable mold and the second mold is filled with rubber or synthetic resin mixed with a directional substance in advance. An elastic base material 3≠ made of material is introduced. Thereafter, the extruders 3 are pushed down to inject the elastic base material 3 into the cavity 2 through a plurality of injection passages 30 bored at the bottom of the material reservoir t.

At this time, the cavity JG is
The elastic base material 34L that is injected into the inside is oriented in the flow direction of the base material 34L because the directional substance mixed in advance is oriented in the flow direction of the base material 34L.
By sequentially filling the cavity 24 from above at a predetermined inclination angle θ, the directional material is oriented in a constant direction at a predetermined inclination angle with respect to the axial direction of the central axis when injection is completed. A ring is formed (see Figure 5).

At the same time, a product substantially the same as the oil seal shown in FIG. 1 is obtained. In this case, as shown in Figure 5, the injection molded product can be removed from the mold, a portion cut out, and then a garter spring can be installed in the specified position as required to obtain a finished product as an oil seal. It will be done. Note that according to the two molds and the λg shown in Figures 1 and 5, it is necessary to cut a part of the molded product, but by creating a mold structure that does not require cutting. , the manufacturing process can be simplified.

As is clear from the embodiments described above, according to the present invention,
When injecting an elastic base material into a mold with a cavity for molding an oil seal of a predetermined shape, a directional substance is mixed into the elastic base material in advance, and the material is injected into the cavity through the injection passage. The directional substance contained in the elastic base material is oriented in a certain direction, and the annular body of the oil seal can be formed so that the orientation of the directional substance has a predetermined inclination angle with respect to the axial direction. In this case, by arbitrarily setting the inclination angle of the injection passage formed in the mold, the inclination angle of the directional material can be set, for example, in the range of jj''. Since the molded product can be immediately commercialized as an oil seal, the manufacturing process is simplified, manufacturing costs are reduced, and quality is stabilized.

On the other hand, since the apparatus for carrying out the method of the present invention is simple in structure and operation, it is possible to easily manufacture oil seals of constant quality. By preparing many types of movable molds, each having a different inclination angle of the injection passage, it is possible to produce a wide variety of oil seals each having a different direction of inclination of the directional material by replacing the movable molds.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of an oil cooler manufactured by the method of the present invention, Figs. 3 is a cross-sectional view of the mold in a state before injection; FIG. 3 is a plan view of the injection passage provided at the bottom of the material reservoir of the movable mold shown in FIG.
Fig. 3 is a sectional view taken along the line rv-ty in Fig. 3, and Fig. J is a sectional view of the mold of the injection molding machine in a state where injection is completed. 10...Annular body 12...Rotating shaft lhiro...cool lip t...garter spring i
tr...Metal cylinder aO...Directional substance, 2.2
...Fixed mold J4<...Movable mold, 2J...
Cavity JJ'...Material storage part 3o...Injection passage Jco...Press device 34A...Elastic base patent applicant Tokushu Kogyo Co., Ltd. FIG, 1 FIG, 3 FIG, 5

Claims (1)

[Claims] (1)゛ A directional substance is mixed in advance into an elastic base material, and the mixture is injection molded into an oil seal-shaped cavity provided in an injection mold through a plurality of spiral injection passages. A method for manufacturing an oil seal characterized by: (2. The method for manufacturing an oil seal according to claim 1, in which the elastic base material is made of rubber or a synthetic resin material. (3) Claim 1/Claim 1) In the method for manufacturing an oil seal, the directional substance is selected from am-type materials such as glass fiber, carbon fiber, and heat-resistant synthetic FF1M, or fine particles such as mica, graphite, talc, and silica having directional properties. (4) A fixed mold and a movable mold are provided to form an oil seal molding cavity of a predetermined shape, a material storage section is provided in the movable mold located above the cavity, and the material of the movable mold is The injection molding is characterized in that a plurality of spirally formed injection passages are provided to communicate with the bottom of the storage part and the upper end of the cavity, and further a suppressor is arranged to face the material storage part of the movable mold. Oil seal manufacturing equipment equipped with a machine.