JP2001232640A - Method for producing mold for tire vulcanization molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a mold for tire vulcanization molding which can save labor in a process for processing/assembling piece blocks which constitute a piece and improve exhaust efficiency in the process. SOLUTION: By integrating one sector S, not each piece block, by a complete article of die casting, processes for processing and assembling the piece blocks 3a, 3b can be eliminated. When the first piece block 3a and the second piece block 3b are cast/laminated by the same kind of a molten metal material, or when the adjacent first and second piece blocks 3a, 3b are cast-joined, since a fine clearance can be formed in the cast-joint part X between the piece blocks 3a, 3b by the solidification shrinkage of the metal material, the clearance can be formed easily during assembling without applying special processing or without placing a member between them to improve exhaust efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a tire vulcanization molding die, and more particularly, to a reduction in labor required for processing and assembling steps of a piece block constituting a piece of a tire, and for a tire vulcanizing step. The present invention relates to a method for manufacturing a tire vulcanization molding die which has improved the exhaust efficiency of a tire.

[0002]

2. Description of the Related Art Conventionally, a sector mold used as one of tire vulcanization molding dies is formed by adjoining a plurality of pieces having irregularities corresponding to at least a profile surface of a tread portion of a product tire to each other. Then, one sector is constituted by mounting it on the back block, and a plurality of sectors are interconnected to constitute an annular sector mold.

[0003] During tire vulcanization molding, air stagnation or gas is generated between the outer peripheral surface of the tire and the molding surface of the mold, and the air or gas forms minute recesses on the surface of the product tire to produce a product. It is known to cause defects. For this reason, a through-hole for venting air, called a vent hole, and a groove for exhausting are conventionally formed in the molding surface of the mold.

However, a rubber material flows into the vent hole and the exhaust groove during vulcanization of the tire and forms spews (burrs, whisker-like rubber projections) on the surface of the product tire. For this reason, finishing work to remove the spew after molding is required, and after removing the spew, the trace of the tire product is left behind and the appearance of the tire product is damaged,
There was the problem of increasing tire noise.

[0005] In recent years, tires with excellent appearance have been developed.
In order to reduce the occurrence of defective products during tire vulcanization molding, a pureless mold (slit vent) in which a vent hole or an exhaust groove is not formed on a mold surface is used.

[0006] The invention of the pures mold is described in, for example, Japanese Patent Application Laid-Open No. 4-223108 (Title of Invention:
Mold for vulcanizing an unvulcanized tire carcass, method for manufacturing the mold, method for vulcanizing a tire using the mold, and Japanese Patent Application Laid-Open No. H10-24423 (Title of Invention: Mold for tire vulcanization molding) Mold and its manufacturing method).

The former invention is a method of assembling a back block in which a tread pattern of a tire is divided for each pitch, and sucking air existing between the tire and a mold from outside through a gap provided between the back blocks. The latter invention is formed by casting a dissimilar metal (SS400) into the base metal (aluminum) of the pattern piece and forming it by a difference in linear thermal expansion coefficient at a tire vulcanization molding temperature (160 ° C.). This is a method of discharging air using a gap. In addition, as a slit vent mold, there is a method of removing air by providing a step between pieces by machining or inserting a spacer between pieces.

[0008]

However, the above-mentioned invention has a problem that it is difficult to secure proper air bleeding at an arbitrary position, and a vacuum device or the like is necessarily required as an exhaust means. In the above invention, a volume necessary for generating a gap due to a difference in linear thermal expansion coefficient between different metals is required, and it is difficult to secure a required gap amount at an arbitrary position. It is difficult to pull out.

SUMMARY OF THE INVENTION It is an object of the present invention to form a gap which can easily form a gap at the time of assembling without performing special processing or intervening members, and form a gap which can secure required exhaust performance at an arbitrary position. It is possible to manufacture tires with good dimensional accuracy and to reduce the occurrence of defective tires during vulcanization molding, to save labor in the processing and assembly process, and to further enhance the exhaust effect. An object of the present invention is to provide a method of manufacturing a mold for sulfur molding.

[0010]

According to the present invention, in order to achieve the above-mentioned object, a plurality of piece blocks are cast and laminated to form a piece, and a fine joint due to solidification shrinkage of a metal material is formed at a joint between the piece blocks. A method of manufacturing a tire vulcanization molding die for forming a gap, wherein a first piece block constituting each pitch and a plurality of pitches is manufactured in advance by casting or machining, and then a spacer and a first piece are formed via a jig. The two-shot molding dies are alternately arranged in series, and the plurality of first piece blocks are arranged on a second shot molding die. Thereafter, the first piece blocks and the second shot molding dies are arranged. A second piece block is manufactured by performing a second shot between the mold and the mold, and an intermediate spacer is removed from the jig while leaving spacers at both ends. After the third molding and the first piece block are respectively disposed and the third shot is performed, each piece block is cast-joined, and the spacers located at both ends are removed. The gist is to perform a fourth shot on both ends and the back of the first piece block to connect and fix the piece blocks for one sector.

According to the present invention, the finished product of die casting is integrated with one sector instead of each piece block, thereby making it possible to omit a processing step and an assembling step of the piece block. Further, when the first piece block and the second piece block are cast and laminated with the same kind of molten metal material, or when the first piece block and the second piece block are adjacent to each other.
When a piece block is spliced, fine gaps can be formed at the seam of the piece block by solidification and shrinkage of the metal material, so gaps can be easily formed during assembly without special processing or intervening members. It is possible to enhance the exhaust effect.

[0012]

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

FIG. 1 is a perspective view of one sector 1 constituting a split type pureeless mold (sector mold) embodying the present invention, and FIG. 2 is a first piece mounted on a back block 2 of the sector 1. FIG. 3 shows a cross-sectional view of a piece 3 (made of aluminum), which is composed of a block 3a and a second piece block 3b.

As shown in FIG. 1, the one sector 1 is mounted on the back block 2 with a plurality of pieces 3 formed with irregularities 5 corresponding to at least the profile surface of the tread portion of the product tire adjacent to each other. It is constituted by doing.

As shown in FIG. 2, the plurality of pieces 3 mounted on the back block 2 are formed by dividing a tread pattern in the tire circumferential direction into a plurality of sections at a fixed pitch or an arbitrary pitch, and each piece is composed of a single piece. Each of the pieces is divided into a plurality of shots by die casting and divided into a first piece block 3a and a second piece block 3a.
b.

A fine gap (0.005 to 0.005) caused by solidification shrinkage of the metal material is formed in the joint portion X of the metal material (the first piece 3a and the second piece 3b) formed by a plurality of shots.
0.06 mm, preferably 0.02 mm).

An exhaust hole 4 communicating with the minute gap is formed below the profile surface of the piece 3, and an exhaust hole communicating with the atmosphere is provided on the back side of the piece 3 although not shown. It is.

In the embodiment of the present invention, the finished product of die casting is not integrated into each piece block, but is integrated into one sector, thereby forming each first piece block 3a.
This eliminates the process of forming the second piece block 3b.

Next, a method for manufacturing a purees mold according to an embodiment of the present invention will be described with reference to FIGS. 3 (a) and 3 (b) to FIG.

First, as shown in FIGS. 3A and 3B,
First, a first shot casting is manufactured by die-casting the first piece block 3a constituting each pitch and a plurality of pitches by using a first shot mold 13a and using an aluminum material.

Next, as shown in FIG.
A plurality of spacers 15 and 15x and a second shot molding die 13b are alternately arranged in series by a length of one sector S via the first piece block 3 and the first piece blocks 3
a is disposed on the second shot molding die 13b.

Thereafter, as shown in FIG. 5, a second shot is produced between the first piece block 3a and the second shot molding die 13b to produce a second piece block 3b. After removing the intermediate spacer 15 while leaving the spacers 15x at both ends, the second shot molding die 13b and the first shot molding die 13b are inserted into the space between the second piece blocks 3b.
By arranging the piece blocks 3a and performing the third shot, the piece blocks 3a and 3b are jointed and connected, and the spacers 1 located at both ends are further provided.
After removing 5x, a fourth shot P is performed on both ends of the piece blocks 3a and 3b and on the back surface of the first piece block 13a, and as shown in FIGS. 13b is connected and fixed.

From the back surface of the first piece block 3a, on the casting line Xa, 3 to 5 mm from the profile surface W.
The air outlet 16 for air escape is formed in the normal direction.

As described above, by integrating one sector S instead of each piece block in the finished product of die casting, the processing steps and assembly steps of the piece blocks 3a and 3b can be omitted. When the first piece block 3a and the second piece block 3b are cast and laminated with the same kind of molten metal material, or when the adjacent first piece block 3a and second piece block 3b are jointed, the piece blocks 3a and 3b Fine gaps can be formed in the joint X by solidification shrinkage of the metal material. Therefore, gaps can be easily formed during assembly without special processing or intervening members, and the exhaust effect can be enhanced. is there.

[0025]

According to the present invention, a plurality of piece blocks are cast and laminated as described above to form a piece, and a fine gap is formed in a joint portion between each piece block due to solidification shrinkage of a metal material. A method for manufacturing a sulfur molding die, in which a first piece block constituting each pitch and a plurality of pitches is manufactured in advance by casting or machining, and then a spacer and a second shot molding die are formed via a jig. And 1
A plurality of the first piece blocks are disposed on a second shot molding die while the lengths of the sectors are alternately arranged in series, and then the first piece block and the second shot molding die are disposed. A second piece block is manufactured by performing a second shot during the process, and an intermediate spacer is removed from the jig while leaving spacers at both ends, and then a second shot forming metal is provided in a space between the second piece blocks. After the mold and the first piece block are respectively arranged and the third shot is performed, each piece block is cast-joined, and the spacers located at both ends are removed. Since the fourth shot is performed on the back of the piece block and the piece block for one sector is connected and fixed,
It has the following excellent effects. (a). A gap can be easily formed at the time of assembling without special processing or intervening members. (b) A tire having good appearance and high dimensional accuracy can be manufactured by forming a gap at an arbitrary position to secure required exhaust performance. (c). The occurrence of defective tires during vulcanization molding can be reduced. (d). Labor saving in the processing / assembly process (work) can be achieved. (e). Since the joint line is provided between the pitches, the exhaust effect can be enhanced.

[Brief description of the drawings]

FIG. 1 is a perspective view of one sector constituting a split-type purees mold (sector mold) embodying the present invention.

FIG. 2 is a cross-sectional view of a piece including a first piece block and a second piece block mounted on a back block of a sector.

FIGS. 3 (a) and 3 (b) are one process diagram of a method for manufacturing a tire vulcanization molding die, and FIG. ) Is AA of (a)
It is arrow sectional drawing.

FIGS. 4A and 4B are two process diagrams of a method for manufacturing a tire vulcanization molding die. FIG. 4A shows a second shot die and spacers alternately arranged to perform a second shot. Sectional view of the process,
(B) is a sectional view taken along the line BB of (a).

FIG. 5 is an explanatory view of a step of removing a spacer at an intermediate portion while leaving spacers at both ends, and performing a second shot for the second time on that portion.

FIG. 6 is an explanatory view of a step of removing a spacer at both ends and performing a third second shot on both end sides of the piece block and the back surface of the first piece block.

FIG. 7 is a cross-sectional view of a completed piece block for one sector, showing a process in which an exhaust hole for air escape is formed on the casting line from the back surface of the first piece block.

FIG. 8 is a side view of FIG. 7;

FIG. 9 is a bottom view as viewed in the direction of arrows CC in FIG. 7;

[Explanation of symbols]

Reference Signs List 1 sector 2 back block 3a first piece block 3b second piece block 3 piece 4 exhaust hole 5 unevenness 13a first shot mold 13b second shot molding mold 14 jig 15 pacer 16 exhaust hole for air escape

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B29L 30:00 B29L 30:00

Claims (2)

[Claims] 1. A method for manufacturing a tire vulcanization mold for forming a piece by casting and laminating a plurality of piece blocks, and forming a fine gap due to solidification shrinkage of a metal material at a joint between the piece blocks. Wherein, in advance, a first piece block constituting each pitch and a plurality of pitches is manufactured by casting or machining, and then the spacer and the second shot forming mold are separated by a jig into a length corresponding to one sector. The plurality of first piece blocks are alternately arranged in series, and the plurality of first piece blocks are arranged on a second shot molding die, and then the second piece block is placed between the first piece block and the second shot molding die. A second piece block is manufactured by performing a shot, and an intermediate spacer is removed from the jig while leaving spacers at both ends, and then a second shot molding die and a first piece block are provided in a space between the second piece blocks. Click a connecting joint casting each piece blocks by performing a third round of shots arranged respectively, after removal of the spacers further located at both ends, both ends and the first piece block
Make the fourth shot on the back of the peace block and get 1
A method for manufacturing a tire vulcanization mold for connecting and fixing sector blocks for sectors. 2. The tire vulcanizer according to claim 1, wherein an exhaust hole for air escape is formed in a normal direction from the back surface of the first piece block on the casting line, leaving 3 to 5 mm from the profile surface. Manufacturing method of molding die.