JPS6161814A - Mold for vulcanizing rubber molded part and manufacture thereof - Google Patents

Abstract

PURPOSE:To enable to obtain a mold, the production time of which is shortened and the cost of which is low, by a method wherein a molded body, onto which the outer shape and character and symbol parts on the surface of a rubber molded part are transferred, is formed by spraying specified spraying metal. CONSTITUTION:Metallic material is sprayed onto the surface of the modeling part of a tire 10. One kind of metal selected from metals with excellent transferring property and thermal conductivity such as zinc, aluminum, copper, nickel or the like or an alloy containing at least one kind of metal out of the metals just mentioned above is used as the metallic material for spraying. The spraying of the above-mentioned metallic material is done by mixing the compressed air having a pressure of 4-8kg/cm<2> with the molten metal so as to cool down to a temperature of 50-80 deg.C in order to obtain a metal deposit with the thickness of 1.5-2mm onto the surface of the tire. Next, reinforcing metal is sprayed under the same conditions as mentioned above onto the outside surface of the resultant molded body 15 with the proper thickness. Material with high thermal conductivity such as aluminum alloy or the like or material with excellent compressive resistance such as nickel alloy or the like is used as the metallic material for reinforcer. After being sprayed and cooled down to ordinary temperature, the final molded body is removed from the tire and cut off the surplus portion in order to obtain a sector mold 14.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mold for vulcanizing a rubber molded product and a method for manufacturing the same, and particularly relates to a mold for vulcanizing a rubber molded product and a method for producing the same. A mold is constituted by a molded body.

[Conventional technology]

Conventionally, in molds for vulcanizing rubber molded products, such as vehicle tires, in addition to casting molds used for vulcanizing green tires, section molds have been used for repairing finished tires. This section mold is made of aluminum casting for repairing tread designs, but when repairing defective parts of raised parts such as tire brands, letters, symbols, etc., only the profile of that part can be cut using a lathe on a steel plate. A section mold called a so-called "bozu mold" is processed, and an unvulcanized sheet rubber is pressed against the raised parts and surrounding areas of other tires of the same type and brand to transfer the raised parts, and then this is vulcanized. It is used in conjunction with a rubber sheet.

[Problem that the invention seeks to solve]

When using a section mold and a rubber sheet together to repair a defective raised part of a tire, fix it by pasting unvulcanized rubber on the repaired part of the tire, then applying a rubber sheet to this part and covering it with the section mold. A method of heating the section mold by applying pressure between the inner surface of the tire and the section mold has been used. However, such repairs using rubber sheets require heating for a long time due to the low thermal conductivity of rubber, which not only lengthens the repair time, but also causes the rubber sheets to wear out after repeated use several times. In addition, cracks occur and the finishing accuracy decreases, so there is a problem that it cannot withstand long-term use.

In addition, both section molds made of cast metal and section molds made of lathe-processed iron plates are expensive to manufacture and require a long period of time to complete.

(Means for Solving the Problems) The invention of a mold for vulcanizing rubber molded products is based on a method in which a type of metal selected from zinc, aluminum, copper, and nickel is applied to part or all of the surface of a ready-made rubber molded product. , or an alloy containing at least one of these metals is thermally sprayed and molded to form a molded product, on which the outer shape of the rubber molded product, the characters on the surface, and the transfer portion of the symbol are formed.

The invention of the method for manufacturing a mold for vulcanizing a rubber molded product is to apply zinc, aluminum, or
4 by melting a metal selected from copper and nickel, or an alloy containing at least moit of these metals.
The sprayed metal is injected with compressed air at a pressure of ~8 kg/- at a temperature of 50 to 80°C to solidify the sprayed metal, and the molded product to which the outer shape, surface characters, and symbols of the rubber molded product are transferred is made into a rubber molded product. It is to be released from the mold.

[Effect]

Since the molded body of the present invention uses a metal or an alloy that has excellent transferability to a ready-made rubber molded product, a highly accurate transfer portion can be formed. Furthermore, since this metal material has excellent thermal conductivity, rubber molded products molded using this mold are of good quality and the vulcanization time is shortened.

In manufacturing the mold of the present invention, compressed air is mixed into the molten metal or alloy and sprayed at a relatively low temperature, so that the surface of the rubber molded product to be molded is not affected by heat. Further, since the manufacturing method of the present invention is a method of thermally spraying a metal or alloy onto the surface of a ready-made rubber molded product to form a mold, it can be easily manufactured in a short period of time.

〔Example〕

1 to 3 show examples in which the present invention is applied to a tire section mold.

FIG. 1 shows a case in which the outer surface of a two-wheel vehicle tire from one side of the tread portion, through the shoulder portion, the sidewall portion, and to the toe surface of the bead portion is molded into a fan shape with a predetermined circumferential length.

In the same figure, the reference numeral 10 indicates a ready-made piece 4, the reference numeral 14 indicates a mold, and 15 and 16 indicate a molded body of the mold 14 and a metal reinforcing body, respectively. Molded body 1 of this mold 14
5 is formed with a transfer portion (not shown) in which the design of the tread portion of the tire 10, the brand of the sidewall portion, and other characters, symbols, etc. are molded.

FIG. 2 shows a case in which the outer surface of a light truck tire from the shoulder portion to the middle portion of the sidewall portion is molded to have a predetermined circumferential length. Mold 1 in this example
The shoulder groove 11 of the tire IO is molded into the molded body 15 of No. 4, and the arc length of the fan-shaped mold 14 in the circumferential direction is lengthened as shown in FIG. 4(b). ,
This is used by cutting it into multiple pieces at appropriate arc length intervals.

FIG. 3 shows a case where only the shoulder groove portion of a large truck or bus tire is molded, and the mold 14 is fitted into the shoulder groove 12 of the tire 10 and is approximately flush with the surface of the shoulder portion. A molded body 15 having a shape, and this molded body 15
A metal reinforcing body 16 is welded to the outer surface of the shoulder groove 12 so as to extend to both sides of the shoulder groove 12 than the width of the outer surface of the tire.

Next, the steps for manufacturing the section molds of each of the above embodiments will be described.

Prepare a new tire with no defects on the surface of the tire to be used for molding, wipe the area to be molded to remove dust and other foreign matter, then apply a mold release agent and let it dry.

Next, a metal material is sprayed onto the surface of the molded portion of the tire using a low-temperature metal spraying machine. As the metal material, a metal selected from among metals with excellent transferability and thermal conductivity such as zinc, aluminum, copper, and nickel, or an alloy containing at least one of these metals is used. Or copper, or an alloy containing at least one of zinc and copper is most preferred. Thermal spraying of this metal material is carried out by mixing compressed air at a pressure of 4-3 kg/Cnt into the molten metal and lowering the temperature to 50-80°C, resulting in a thickness of 1.5-2 mm on the tire surface. I will make it happen.

Next, reinforcing metal is thermally sprayed to an appropriate thickness on the outer surface of this molded body under the same conditions as above. As the metal material for this reinforcing body, a material with high thermal conductivity such as an aluminum alloy, or a material with excellent compression resistance such as a nickel alloy is used.

After spraying the metal material of the reinforcing body, the section mold of the present invention can be obtained by allowing the reinforcing body to cool down to room temperature, then releasing it from the tire, and cutting off the excess thickness.

FIG. 4 shows the condition when a tire is repaired using the section mold described above. Unvulcanized rubber is pasted on the repaired area of the repaired tire 20, and the molded body 15 of the section mold 14 is applied to this area, placed on the hot platen 30, and the presser fitting 31 is placed on the inner surface of the tire. After the tire 20 is clamped between the holding fitting 31 and the section mold 14 by the clamp 32, when the hot platen 30 is heated, the unvulcanized rubber at the repaired area is vulcanized by the heat transferred to the section mold 14. It has become so.

FIG. 5 shows another embodiment of the present invention, in which a rubber molded product'
This invention is applied to the molding of a finished product.

The rubber molded product of this example is a tire-shaped rubber ashtray. The mold has an upper mold 14a as shown in FIG.
and a lower mold 14b, and this upper mold 14a and lower mold 14b
As shown in Figures (b) and (e), zinc alloy (ZnS
) is sprayed onto molded bodies 15a and 15b, and the outer reinforcing bodies 16a and 16b are sprayed with aluminum to form an upper mold laminate 17a and a lower mold laminate 17b. The lower mold laminate 17b is shaped by lathe processing,
They are fitted into an upper formwork 18a and a lower formwork 18b made of iron, respectively.

When using this mold to form a rubber ashtray,
After putting unvulcanized rubber into the lower mold 14b and concentrically covering it with a core (not shown), when the upper mold 14a is placed on top of it and pressed, the unvulcanized rubber is pushed out into the space of the upper mold 14a. You can make a raw ashtray with the same shape as the model tire. By heating this mold, the raw ashtray is vulcanized and the product ashtray becomes zero.
7.

In the molds of each of the above embodiments, a reinforcing metal is sprayed onto the outer surface of a molded body molded using metal sprayed onto a ready-made rubber molded product to form a laminate. If the same type of metal or alloy is used for thermal spraying with the reinforcing body, there is no need to distinguish between the molded body and the reinforcing body since they are made of the same material, and the thickness of the sprayed metal of the molded body must be adjusted in terms of strength. If the thickness is sufficient, the mold will be composed of only the molded body in this case as well.

〔Effect of the invention〕

As explained above, since the present invention is configured to mold a ready-made rubber molded product using a metal or alloy with excellent transferability, it is possible to form a highly accurate transfer part on the molded product. Moreover, since the metal material of the molded body has excellent thermal conductivity, according to this invention, a rubber molded product of good quality can be vulcanized in a short time, and it is especially useful for repairing rubber molded products. A mold suitable for use as a section mold is obtained.

In addition, the mold of the present invention can be easily manufactured by thermally spraying a metal or alloy onto the surface of a ready-made rubber molded product, so that conventional molds can be manufactured by skilled workers over a long period of time. Unlike the previous method, a W8 kneading worker is not required, and an inexpensive mold can be obtained which significantly shortens the manufacturing period and significantly reduces the manufacturing cost.

[Brief explanation of the drawing]

1 to 3 show examples of tire section molds, respectively. Figure (b
) is a rear view of the mold, FIG. 3 (Fl) is a perspective view during mold making, FIG. 3 fb) is a perspective view of the mold, and FIG. 4 is a side view showing the state when repairing a tire using a section mold. FIG. 5 shows a mold for vulcanization of a rubber ashtray, and ta+ in the same figure is a sectional view showing a state in which the upper mold and lower mold are combined;
FIG. 1B and (C) are side views showing the molding states of the upper mold and the lower mold, respectively, in half cross section. In the figure, 10 is a ready-made tire, 14 is a mold, and 15 is a molded body. Figure 1, (a) (b) Figure 2, Figure 4, Figure 5 (a) (b), 7° snow (C)

Claims (2)

[Claims] (1) A type of metal selected from zinc, aluminum, copper, and nickel, or an alloy containing at least one of these metals, is sprayed onto part or all of the surface of a ready-made rubber molded product and molded. , a mold for vulcanization of a rubber molded product, which is constituted by a molded body on which a transfer portion of the outer shape, characters and symbols on the surface of the rubber molded product is formed. (2) 4 to 8 kg of a metal selected from zinc, aluminum, copper, and nickel, or an alloy containing at least one of these metals, is melted on part or all of the surface of a ready-made rubber molded product. The sprayed metal is injected with compressed air at a pressure of /cm^2 at a temperature of 50 to 80°C to solidify the sprayed metal, and the molded product to which the outer shape, characters and symbols on the surface of the rubber molded product are transferred is made into a rubber molded product. A method for producing a mold for vulcanizing a rubber molded product, characterized in that the mold is released from the mold.