JP2742497B2 - Manufacturing method of rubber molded product - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rubber molded product, and more particularly, to a rubber molded product capable of obtaining a high quality rubber molded product by keeping the weight of kneaded rubber charged in a molding die constant. And a method for producing the same.

[0002]

2. Description of the Related Art A general method of manufacturing a rubber molded article having various types of reinforcing rings, for example, an oil seal, includes a kneading step of mixing and dispersing a compounding chemical into raw rubber to form a kneaded rubber; The rubber is formed into a predetermined hose shape by using an extruder, and the hose-shaped kneaded rubber is cut at predetermined intervals in the length direction to form an annular kneaded rubber, and then the weight and deformation of the annular kneaded rubber. A preparation step of selecting only those having a degree within a predetermined range, and setting the annular kneaded rubber and a reinforcing ring having been subjected to a desired treatment into a plurality of cavities of a desired molding die, followed by vulcanization molding It has a molding process of vulcanizing with a machine to obtain a molded product, and a finishing process of removing unnecessary portions such as burrs from the molded product.

[0003]

However, in the above-described conventional method of manufacturing a rubber molded product, the weight (the charged weight) of the annular kneaded rubber formed in the preparation step of being set in the cavity of the molding die is set. ) Is large and the burr of the molded product cannot be kept constant, and the shape of the annular kneaded rubber is deformed and cannot be positioned at a predetermined position in the cavity of the molding die. Not only is not constant, but also there is a problem that it is difficult to automate the molding process (from charging kneaded rubber and reinforcing ring to demolding of the molded product). In addition, there was a problem that the reinforcing ring and the kneaded rubber could not be integrally handled in the molding process, and automation was difficult.

[0004] The present invention has been made in view of these points, and overcomes the above-described problems in the conventional art.
Manufacture of rubber molded products that keeps the weight of the kneaded rubber set in the cavity of the molding die constant, and enables the reinforcement ring and kneaded rubber to be handled integrally in the molding process, facilitating the automation of the molding process. The aim is to provide a method.

[0005]

According to a first aspect of the present invention, there is provided a method of manufacturing a rubber molded article having a reinforcing ring.
A kneading step of mixing and dispersing the compounding chemicals in the raw rubber to form a kneaded rubber; a preforming step of preforming the kneaded rubber integrally with the reinforcing ring with a shape forming mold; Reinforcement ring preformed from
A molding step of removing the kneaded rubber and thereafter vulcanizing the kneaded rubber integrally formed on the reinforcing ring with a molding die to obtain a molded product.

According to a second aspect of the present invention, there is provided a method of manufacturing a rubber molded product according to the first aspect, wherein
The process is performed at a predetermined temperature state .

Further, the method for producing a rubber molded product according to the present invention according to claim 3 is the method according to claims 1 and 2,
It is characterized in that the preforming step and the forming step are performed continuously .

[0008]

According to the method for manufacturing a rubber molded product of the present invention having the above-described structure, the reinforcing ring is formed by mixing the kneaded rubber with the mold for forming the shape.
Since the preform can be integrally formed, the weight of the kneaded rubber set in the cavity of the molding die is kept constant, and the reinforcing ring and the kneaded rubber can be integrally handled in the molding process. Automation of the molding process can be facilitated.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

An embodiment of the method for producing a rubber molded product according to the present invention will be described with reference to an oil seal.

FIG. 1 is a block diagram for explaining the steps of a method for producing a rubber molded product according to the present invention, FIG. 2 is an explanatory diagram for explaining preforming by a shape forming die, and FIG. It is a longitudinal cross-sectional view which shows the principal part of the molded article formed by the manufacturing method of such a rubber molded article.

As shown in FIG. 1, the method for producing a molded rubber article of the present embodiment comprises a kneading step 3 in which a compounding chemical 2 is mixed and dispersed in a raw rubber 1 to form a desired kneaded rubber (not shown).
A preforming step 5 for integrally preforming the kneaded rubber and the reinforcing ring 4 into a predetermined shape; and vulcanizing the preformed kneaded rubber and the reinforcing ring 4 with a molding die (not shown) and vulcanizing them. And a finishing step 7 of removing unnecessary portions such as burrs (not shown) from the molded product and installing a garter spring (not shown) as necessary.

The above steps will be described in more detail.

In the kneading step 3, the raw rubber 1 adjusted to a predetermined amount and various compounding chemicals 2 are mixed with a known kneading roll (not shown) or a closed high-temperature kneading roll called a Banbury mixer. The desired kneaded rubber (not shown) is obtained by dispersing. The kneaded rubber may be formed, for example, in a cylindrical shape or the like in order to facilitate handling in the next preforming step 5.

As shown in FIG. 2, the preforming step 5 includes a reinforcing ring in which an appropriate shape forming die 9 having a cavity 8 of a predetermined shape is subjected to necessary pretreatment (such as application of an adhesive). 4, the kneaded rubber 10 having a predetermined shape is integrally formed on the reinforcing ring 4 by, for example, injecting the kneaded rubber 10 into the cavity 8. As a result, the reinforcing ring and the kneaded rubber can be integrally handled.

The preforming step 5 includes a known parts feeder (not shown) for arranging the reinforcing rings 4 and a desired not-shown part for setting the aligned reinforcing rings 4 at predetermined positions in the shape forming die 9. And a kneading rubber injection device 15 comprising a desired pot 13 and a piston 14 for supplying kneaded rubber 10 to the shape forming die 9 and a reinforcing ring 4 in the shape forming die 9. It can be easily automated by a suitable unloading device (not shown) that takes out the reformed kneaded rubber 10a and unloads it to a desired position. Then, the shape and weight (volume) of the kneaded rubber 10 are always kept constant by the cavity 8 of the shape forming die 9, and the variation can be reliably prevented. When both the kneaded rubber 10 and the reinforcing ring 4 to be supplied to the shape forming die 9 are heated to, for example, about 60 ° C., the kneaded rubber 10 at the contact portion 11 between the reinforcing ring 4 and the kneaded rubber 10 becomes sticky. It is possible to prevent the separation between the reinforcing ring 4 and the kneaded rubber 10 with the property, and to shorten the vulcanization time in the next step by continuously performing this step and the next step at a desired timing. In addition, the vulcanization timing of the kneaded rubber 10 and the reaction timing of the adhesive (not shown) applied to the reinforcing ring 4 can be optimized. Further, the reinforcing ring 4 and the kneaded rubber 10 taken out of the shape forming die 9 can be reliably and integrally handled.

In this embodiment, the kneaded rubber 10
Is formed integrally with the reinforcing ring 4 using the shape forming die 9, but the shape and weight of the kneaded rubber 10 can always be kept constant, and the reinforcing ring 4 is formed in the molding process.
And the kneaded rubber 10 as long as they can be integrally handled, and are not particularly limited to the configuration of the present embodiment.

The surface of the cavity 8 of the shape forming die 9 is preferably coated with a fluororesin or the like in order to ensure releasability from the kneaded rubber 10.

The molding step 6 is shown in FIG. 3 by holding the kneaded rubber 10a preformed integrally with the reinforcing ring 4 at a predetermined temperature and pressure for a predetermined time using a desired molding die (not shown). Such a molded product 12 is obtained. This molding die can be easily automated by using an appropriate molding device such as a rotary press (not shown). A kneaded rubber 10a integrally formed with a reinforcing ring 4 set in a molding die.
Since the two are integrated in the pre-molding step 5 as described above, they can be surely handled integrally unlike the prior art, so that they can be easily set in a molding die in one step. That is, the molding process can be easily automated. The kneaded rubber 10a preformed integrally with the reinforcing ring 4 has no deformation of its shape and does not vary in weight. Can be reliably and easily set at the position, and the pressurized state at the initial stage of molding can always be set to the optimum state, and the quality of the molded product 12 can be reliably improved. The burrs (not shown) of the molded product 12 thus formed can always be kept in a constant state.

In the finishing step 7, an unnecessary part such as a burr (not shown) is removed from the molded product 12 by a known finishing device (not shown), and a garter spring (not shown) is attached. Zu) is to get. When removing burrs from the molded product 12, the burrs of the molded product 12 are always constant as described above, so that automation can be easily achieved.

Although the present embodiment has been described by exemplifying an oil seal, the present invention can naturally be applied to a rubber molded product having inserts such as various reinforcing rings.

Further, the present invention is not limited to the above-described embodiment, but can be modified as required.

[0023]

As described above, according to the method for manufacturing a rubber molded product of the present invention, the weight of the kneaded rubber set in the cavity of the molding die is kept constant, and the reinforcing ring and the kneading ring are used in the molding process. An extremely excellent effect is obtained in that the rubber and the rubber can be handled integrally, and automation of the molding process can be facilitated.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating steps of a method for producing a rubber molded product according to the present invention.

FIG. 2 is an explanatory view for explaining preforming with a shape forming die.

FIG. 3 is a longitudinal sectional view showing a main part of a molded product formed by the method for producing a rubber molded product according to the present invention.

[Explanation of symbols]

 Reference Signs List 3 Kneading step 5 Pre-molding step 6 Molding step 7 Finishing step 9 Shape forming die 10 Kneaded rubber 10a Preformed kneaded rubber 12 Molded product

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29K 105: 24 B29L 31:26

Claims (3)

(57) [Claims] 1. A method for producing a molded rubber article having a reinforcing ring, comprising: a kneading step of mixing and dispersing a compounding chemical into raw rubber to form a kneaded rubber; A preforming step of preforming with the shape forming mold, and a preforming step preformed from the shape forming mold.
Removing the strong ring and the kneaded rubber and then vulcanizing the kneaded rubber preformed integrally with the reinforcing ring with a molding die to obtain a molded product. . 2. The method according to claim 1, wherein the preforming step is performed at a predetermined temperature.
The method for producing a rubber molded product according to claim 1, wherein the method is performed. 3. The preforming step and the forming step are continuously performed.
Method for producing a rubber molded article according to claim 1 or claim 2, characterized in that to.