JPS6349407A - Mold for vulcanizing elastomer article and its manufacture - Google Patents

Abstract

PURPOSE:To manufacture the title article, at short delivery and a low cost by reducing a manufacturing man-hour drastically, by a method wherein a vulcanization mold is constituted of an inner shell of a predetermined thickness having a molding part corresponding to an outside surface form and an outer shell having an outside form conforming to a vulcanizing equipment, in the vulcanizing mold of an elastomer article. CONSTITUTION:A second core material 11 is fitted in a final mold 9 made of plaster containing a first core material 7 and a positioning jig 12 is fixed on the core material 11. Then an inner shell 1 is formed by manufacturing a spray coating 15 on the surfaces of them, the other end 1b of the inner shell corresponding to a part of the positioning jig 12 is fitted in a positioning groove 2c provided on an outer shell 2, and an intermediate part 1c of the inner shell 1 is held by a positioning screw 3 screwed to the outer shell 2. Therefore, not only the final mold 9 is reinforced, but also the inner shell 1 can be positioned precisely without bending to the outer shell 2, thus a tire vulcanizing mold of high dimensional accuracy can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Field of Application> The present invention relates to a mold for the vulcanization of elastomeric articles, particularly tires, and a method for producing the same.

<Prior Art> Conventionally, as this type of tire vulcanizing mold, there are molds shown in FIGS. 6 and 7, for example. This tire vulcanization mold 20 is manufactured by casting aluminum into a pair of upper and lower half tread rings 22 and 22' (see Fig. 6), each of which has an uneven molded part 21 corresponding to the tread pattern of the tire on the inner periphery. These shells are assembled into a pair of upper and lower disc-shaped shells 23 and 23 (see FIG. 7) made of cast steel or by cutting a steel ingot, facing each other.

In addition, as another conventional example, small pieces (pattern segments) equipped with molded parts corresponding to the tread pattern are manufactured by aluminum casting, and these pieces are sequentially arranged in the circumferential direction and assembled into the same shell 23.23° as described above. It is known that the tread pattern is directly engraved into a mold made of steel or cast steel.

However, the conventional tire vulcanization mold described above requires a large number of man-hours to manufacture, takes a long time to complete, and therefore has a problem in that the manufacturing cost is high. Another problem is that it is difficult to modify the mold due to changes in the tire design, repair it when it is damaged, and reuse it when it is no longer needed.

<Object of the invention> Therefore, the object of the present invention is to significantly reduce manufacturing man-hours,
Provided is a mold for vulcanizing elastomer articles that can be manufactured in a short delivery time and at low cost, and can be easily modified, repaired, and reused by making a part of the mold replaceable, and also provides a method for manufacturing this vulcanization mold. It is to be.

<Structure of the Invention> In order to achieve the above object, a mold for vulcanizing an elastomer article according to the first invention: an inner shell of a predetermined thickness having a molded portion corresponding to the outer surface shape of the elastomer article to be vulcanized; and an outer shell having an outer shape compatible with a vulcanizing device, and a second invention is characterized in that the inner shell has a predetermined thickness and has a molded portion corresponding to the outer surface shape of the elastomer article to be vulcanized. It is characterized by comprising: an outer shell having an outer shape compatible with a vulcanizing device; and a backing layer filled in a gap formed between the inner shell and the outer shell.

Furthermore, in the method for manufacturing a mold for vulcanization of an elastomer article according to the third aspect of the invention, the inner shell material is sprayed to a predetermined thickness onto the final mold to which the positioning jig is fixed, while the inner shell material is sprayed to a predetermined thickness. After manufacturing an outer shell with an outer shape that fits the vulcanizing device using a material and assembling the outer shell into an inner shell from which the positioning jig has been removed, the gap between the outer shell and the inner shell is fixed. The final mold is removed after the backing material is filled with a backing material that has fluidity and hardens.

<Example> Hereinafter, the present invention will be explained in detail with reference to an example of a tire vulcanizing mold shown in the drawings.

Figure 1 (a) shows the lower half of the tire curing mold.
1 is a cross-sectional view, in which molded parts 1a and lb correspond to the shapes of the tread part and sidewall part of the tire to be vulcanized;
2 is an annular outer shell having an L-shaped cross section and whose outer shape is compatible with a tire vulcanizing device (not shown); 3 is a ring at the bottom of this outer shell 2 in the circumferential direction A positioning screw 4 is screwed into a screw hole 2a penetrated at a predetermined interval, and one end of the positioning screw 4 is fitted into an annular positioning groove 2C provided in the upper part of the inner circumferential wall 2b of the outer shell 2, and the other end is inserted into the outer shell 2. This is a backing layer filled between the inner shell 1 and the outer shell 2 whose intermediate portion is adjusted and held by the positioning screw 3 so as to be at the same height as the upper end of the outer peripheral wall 2d of the inner shell 1 and the outer shell 2.

The inner shell l is made of gypsum or the like, as will be described later.
The surface of the final mold in the shape of a split doughnut is made of a low melting point metal (LI) such as a bismuth alloy, with a curvature of 300°C) and heat resistance (m, p).

It is manufactured by manually spraying Plasdec (250 to 300°C) multiple times, or by similarly vacuum spraying a high melting point metal such as nickel alloy to create a film with a thickness of about 5 to 50 degrees centigrade. The outer shell 2 is manufactured by casting 99 into a predetermined shape or by machining mild steel or free-cutting steel, and has screw holes 2a screwed in predetermined positions, and inner peripheral wall 2b positioning grooves 2C.
and the inner shell height matching surface 2e are machined, respectively. The backing layer 4 may be made of a fluid and solidifying material such as a low-melting point metal such as a bismuth alloy, a heat-resistant (m, p, ≠ 300°C) plastic, or an adhesive (for example, the product name "``Belometal''), etc., into the inner shell 1 and outer shell 2.
It is formed by filling in between. The upper half of the tire curing mold also has the same configuration as described above, and both the upper and lower molds are mounted facing a tire curing device (not shown), and
A known beat ring is fitted into the upper end of the inner circumferential wall 2b of the outer shell 2, which is the base of the inner shell 1, as shown by the two-dot chain line in FIG.

In addition, as shown in FIG. 1 (B), in another implementation for deaf people, the backing layer is omitted and only the inner shell 30 and outer shell 3L are used.
It may also have a layered structure. In this case, the inner shell 30 is not different from the above embodiment, so a description thereof will be omitted. The outer shell 31 is precast or machined so that the outer shape is compatible with the tire vulcanizer and the inner shape matches the outer shape of the inner shell 30. The inner shell 30 and the outer shell 31 can be integrated with adhesive, brazing, or the like. This embodiment eliminates the need for positioning screws.

FIGS. 2 to 5 sequentially show an example of the method for manufacturing a tire vulcanization mold of the present invention.

First, as shown in FIG. 2, a partition vibro is inserted into the center hole 5b of a disc-shaped rubber mold 5, which has an uneven part 5a corresponding to the shape of the tread part and sidewall part of the tire.
A disk-shaped first core material 7 made of wood or aluminum and having a positioning hole 7a in the center is fixed to the upper end of this partitioning vibro with its upper surface flush with the upper surface of the rubber mold 5, and the first core material 7 is fixed to the upper end of the partition vibro. 7 is supported by the core support 8.

Then, gypsum is poured into the cavity formed by the rubber mold 5 and fixed to the outer circumference of the first core material 7, thereby producing a final mold 9 in the shape of a halved donut. Next, the final mold 9 integrated with the first core material 7 is taken out from the rubber mold 5 and placed upside down on the stand lO as shown in FIG. A disk-shaped second core material 11 that fits and has the same height as this is fixed, and a disk-shaped positioning jig 12 that covers the base 9a of the final mold 9 is fixed on top of this second core material 11. , A vent piece 13 made of plus deck or metal and a side wall pattern or letter piece 14 are pasted on the final mold 9 at a predetermined position as necessary.

Next, a thermal spraying device is used to coat a part of the surface of the final mold 9 and the positioning jig 12 with, for example, a bismuth alloy (
The product name "rMCP Metal") was manually sprayed several times, and the fourth
After making a film 15 with a thickness of about 20RR as shown in the figure, mark the unnecessary parts 15a and I5b at the tip and rear end of this film with arrows A and B.
Cut as shown in and remove the positioning jig 12. The film 15 thus formed forms the inner shell 1. On the other hand, an annular outer shell 2 is produced by casting, for example, cast steel, and machined a screw hole 2a at the bottom, a positioning groove 2c and an inner shell height matching surface 2e at the inner circumferential wall 2b, respectively, and manufactures the screw hole 2a. Screw the positioning screw 3 onto 2a.

Thus, as shown in FIG. 5, one end 1a of the inner shell 1 is fitted into the positioning groove 2C of the outer shell 2, and the other end 1b of the inner shell 1
The inner shell and the outer shell are assembled together by holding the intermediate part 1c with the positioning screw 3 so that it is at the same height as the upper end of the outer peripheral wall 2d of the inner shell 1. After making an air vent hole 16 diagonally penetrating through the final mold 9 and the first core material 7, for example, molten bismuth alloy is poured into the gap (arrow) between the inner shell 1 and the outer shell 2, left to cool, and solidified to form a backing layer. form 4. In another embodiment, a pasty backing material such as Verometal (
The backing layer may be formed by attaching a hardening agent thickly to the outer surface of the inner shell and the inner surface of the outer shell in advance, and then fitting and pressing the inner and outer shells and leaving them to harden. Finally, the integrated inner shell l.

Backing layer・1. Outer shell 2 to heartwood 7. The final mold 9 made of plaster containing II is removed to complete the production of the tire vulcanization mold.

In the above embodiment, after the second core material 11 is fitted into the final mold 9 made of plaster including the first core material 7 and the positioning jig 12 is fixed thereon, a thermal spray coating 15 is formed on these surfaces and the interior is coated. shell 1
The other end 1b of the inner shell corresponding to the positioning jig 12 is fitted into the positioning groove 2C provided in the outer shell 2, and the middle part 1c of the inner shell 1 is fitted into the outer shell 2. Since it is held by screwed positioning screws 3, the final mold 9 is reinforced, and the inner shell 1 can be accurately positioned with respect to the outer shell 2 without bending, making it possible to create a tire vulcanizing mold with high dimensional accuracy. can be manufactured. In addition, since the air vent hole 16 is made to allow the air inside to escape when filling the backing material, no pores or cavities are formed in the backing layer 4, and a good tire vulcanization mold can be manufactured. Furthermore, the outer shell and backing layer 4 of the mold that are no longer used for production can be easily diverted to other molds, and the inner shell can be replaced by heating the mold and melting and removing the backing layer. Can be done. With this revolutionary tire vulcanization mold manufacturing method! The number of man-hours required for I-S construction can be significantly reduced compared to the conventional method. In particular, when a backing layer is provided, the effect of shortening the delivery time is remarkable, for example, the manufacturing time that conventionally took around 60 days was shortened to 40 days, and the mold price was also reduced by about 20% due to the reduction in man-hours.

Note that the material for the inner shell L is not limited to the plaster of the example, but may also be wax for molds or wood whose surface does not melt by thermal spraying.

Metals with a lower melting point than plastics, rubber, and thermal spray metals can be used, and thermal spray materials are not limited to bismuth alloys, but can also be heat-resistant plastics and nickel alloys as mentioned above, and backing materials can also be adhesives such as vero metal. It's okay. Furthermore, it goes without saying that the present invention is applicable to vulcanization molds for elastomer articles having various complex patterns in addition to tires.

<Effects of the Invention> As is clear from the above description, the mold for vulcanizing an elastomer article of the present invention has an inner shell of a predetermined thickness and a molded portion corresponding to the outer surface shape of the elastomer article to be vulcanized. It has a two-layer structure consisting of an outer shell with an external shape that fits the vulcanizing device, or a three-layer structure consisting of a backing layer filled between the inner shell and the outer shell. Since it uses a unique manufacturing method such as metal spraying to form the mold, it can significantly reduce manufacturing man-hours, reduce mold costs by reducing man-hours, and easily modify, repair, and reuse by replacing only the inner shell. It has the remarkable effect of being easy to use and economically efficient.

[Brief explanation of the drawing]

Figure 1 (a) is a 1/2 sectional view of the lower half of the three-layer tire curing mold of the present invention, and Figure 1 (b) is the lower half of the two-layer tire curing mold. 2 to 5 are cross-sectional views sequentially illustrating the method for manufacturing a tire vulcanization mold of the present invention, and FIG. 6 is a cross-sectional view. FIG. 7 is a diagram showing a conventional tire vulcanization mold. ■... Inner shell, la... One end, 2... Outer shell, 2C.
...Positioning groove, 3...Positioning screw, 4...Backing layer, 5...Rubber mold, 7...First core material, 9...
・Final mold, 12... Positioning jig, 15... Film. Patent applicant Agent: Sumitomo Rubber Industries, Ltd.
Person: Patent attorney Okiichi Oki and two others Figure 4 Figure 5 Leap Figure 2 Figure 6 Procedural amendment September 24, 1988 Patent application No. 194951 No. 2 Title of invention For vulcanization of elastomer articles Mold and its manufacturing method 3, Name of the person making the amendment: Sumitomo Rubber Industries (2nd type company representative: Katsura 1) Shizuo 4, Agent 5, Date of amendment order: Voluntary 7, In the statement of contents of the amendment, The following parts are corrected: 1. Detailed description of the invention column, page 5, line 20 to page 6, line 1 "Heat resistant (m, p, mi 250-300℃) plus deck" First of all, please remove it.

Claims (3)

[Claims] (1) Vulcanization of an elastomer article characterized by comprising an inner shell having a predetermined thickness and a molded portion corresponding to the outer surface shape of the elastomer article to be vulcanized, and an outer shell having an outer shape compatible with a vulcanizing device. Mold for sulfur. (2) an inner shell of a predetermined thickness having a molded portion corresponding to the outer surface shape of the elastomer article to be vulcanized; an outer shell having an outer shape compatible with the vulcanizing device; and a space between the inner shell and the outer shell. A mold for vulcanizing an elastomer article, comprising a backing layer filled in a formed gap. (3) The inner shell is produced by thermal spraying the inner shell material to a predetermined thickness on the final mold with the positioning jig fixed, while the outer shell material is used to produce an outer shell with an external shape that fits the vulcanization equipment. Then, after the outer shell is fitted to the inner shell from which the positioning jig has been removed and assembled together, the gap between the outer shell and the inner shell is filled with a backing material that has fluidity and hardens. A method for producing a mold for vulcanization of an elastomeric article, characterized in that the final mold is removed after the material has solidified.