JP2001162624A - Apparatus for inspecting air leak of mold for vulcanizing and molding tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus for inspecting the air leak of a mold for vulcanizing and molding a tire capable of easily sorting a piece block having proper air leak quantity and capable of correcting even a piece insufficient in air leak quantity to manufacture a tire good in appearance and high in dimensional accuracy and capable of reducing the generation of an inferior tire at a time of vulcanization and molding. SOLUTION: In an air leak inspecting apparatus 10, a pair of a fixed block 12 and a movable block 13 for holding a piece 3 airtightly are horizontally arranged in a water tank 11 at mutually opposed positions. The fixed block 12 has a supply passage 14 for introducing compressed air into an exhaust hole 4 and the terminal part of the supply passage 14 of the fixed block 12 is connected to a compressed air supply source 18 through a piping 17. The movable block 13 is constituted so as to press and fix piece blocks 3a, 3b to the fixed block 12 through a fluid pressure cylinder 19 such as an air cylinder or a hydraulic cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air leak inspection apparatus for a tire vulcanization molding die, and more particularly to a puree mold after molding (to the extent that a rubber material melted during tire vulcanization does not flow out). The present invention relates to an air leak inspection device for a tire vulcanization molding die which can easily perform an air leak inspection of a mold having minute vent holes and exhaust grooves.

[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).

[0007]

What is important in the above pureless mold is that when a tire is vulcanized by using the pureless mold, a necessary air leak amount is secured at a necessary portion. What you can do. If this amount of air leak cannot be ensured, air remains in the mold during vulcanization of the tire, and a dent or the like is formed on the tire surface, resulting in a so-called light failure.

However, it is not known whether the purees mold has secured the necessary air leak amount or not, since it is not actually tried to vulcanize the tire. There was no device for checking whether the leak amount was secured.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to easily select a piece block having an appropriate amount of air leak in a puree mold and to correct a piece having an insufficient amount of air leak to obtain a good appearance and high dimensional accuracy. An object of the present invention is to provide an air leak inspection device for a tire vulcanization molding die that can manufacture a tire and reduce the occurrence of defective tires during vulcanization molding.

[0010]

According to the present invention, there is provided a tire vulcanization molding for inspecting an air leak amount of a minute gap due to solidification shrinkage of a metal material formed at a joint portion between piece blocks. An air leak inspection device for a mold, wherein a pair of fixed blocks and a movable block that hold the piece block in an airtight manner are disposed at positions facing each other, and the fixed block is a joint of the piece block. A supply passage for introducing a pressurized gas into an exhaust hole formed in the portion, the supply passage being configured to be connected to a pressurized gas supply source, and the movable block being a piece block via a fluid pressure cylinder. Is configured to be pressed and fixed to the fixed block side.

According to the present invention, there is provided a piece which is constructed as described above and is divided into a plurality of shots by die-casting and formed by casting and laminating, and a joint between the piece blocks of the piece is formed by solidification shrinkage of a metal material. A piece block of a tire vulcanization molding die having a minute gap is disposed between a fixed block and a movable block of an air leak inspection device, and is air-tightly fixed.

Then, a pressurized gas having a predetermined pressure is supplied from a pressurized gas supply source to a supply passage of the fixed block, and the pressurized gas is introduced into an exhaust hole of a joint portion of the piece block.
In the case of visually checking the air leak amount of the piece block by leaking bubbles in the water, water is poured into a water tank and bubbles from the joint portion of the piece block are visually checked.

When the air leak amount is to be inspected in the atmosphere, a viscous liquid such as soapy water is attached to the profile surface of the piece block in advance, and the viscous liquid bubbles are visually checked.

By inspecting the amount of air leak of the piece block by such a method, it is possible to easily select a piece block having an appropriate amount of air leak,
A tire having a good appearance and high dimensional accuracy can be manufactured by correcting a piece having an insufficient air leak amount, and the occurrence of defective tires at the time of vulcanization molding can be reduced.

[0015]

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

FIG. 1 is a schematic configuration diagram of an air leak inspection apparatus 10 for a tire vulcanization molding die embodying the present invention. FIG. 2 is a diagram illustrating a split-type tire vulcanization molding die (sector mold). FIG. 3 is a perspective view of one sector 1 and FIG. 3 is a sectional view of a piece 3 (made of aluminum) composed of a first piece block 3a and a second piece block 3b mounted on the back block 2 of the sector 1.

In the embodiment of the air leak inspection apparatus 10, a pair of fixed blocks 12 and movable blocks 13 for holding the pieces 3 in a water tank 11 in a gas-tight manner are horizontally arranged at positions facing each other.

As shown in FIG. 1, the fixed block 12 has a supply passage 14 for introducing a pressurized gas into an exhaust hole 4 formed in a joint portion X of the piece blocks 3a and 3b. A terminal of the supply passage 14 of the fixed block 12 is connected to a pressurized gas supply source 18 such as a pump installed outside the water tank 11 via a pipe 17 having a pressure gauge 15 and an electromagnetic switching valve 16. .

The movable block 13 is provided with a hydraulic cylinder 1 such as an air cylinder or a hydraulic cylinder.
The pressure blocks 20 a and 20 b of the fluid pressure cylinder 19 are provided with a pump 22 through a pipe 22 having an electromagnetic switching valve 21. Pressure supply 23 is connected.

The piece block holding surfaces 12a, 13a of the fixed block 12 and the movable block 13 have
Elastic members 24a, 24b for sealing such as silicone rubber
Are mounted, and the fixed block 12 and the movable block 13
Thus, the side surfaces of the piece blocks 3a and 3b are air-tightly fixed by pressure. 25 is the elastic member 2
4a, the piece blocks 3a, 3b
The exhaust hole 4 formed in the joint portion X of the above and the terminal portion of the supply passage 14 are communicated.

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

As shown in FIG. 3, the plurality of pieces 3 mounted on the back block 2 are formed by dividing the 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 small 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 (not shown). It is.

Next, a method of inspecting an air leak of a tire vulcanization mold will be described.

First, when performing an air leak inspection of the piece blocks 3a and 3b of the tire vulcanizing mold in the water tank 10, the water in the water tank 10 is drained or filled with water. Piece blocks 3a and 3b are arranged between the fixed block 12 and the movable block 13, and the exhaust holes 4 formed in the joint portions X of the piece blocks 3a and 3b correspond to the through holes 25 of the elastic member 24a. The movable block 13 is moved while correcting so that the piece block 3 is held by the piece block holding surfaces 12a and 13a.
a, 3b are hermetically pressed and fixed.

In order to perform an air leak inspection under the water surface from such a state, the piece blocks 3 a and 3 b are submerged in a state where a predetermined amount of water is put in the water tank 10, and the pressurized gas supply source 18 Pressurized gas (0.01MP in this embodiment)
a ~ 0.1MPa). Then, the pressurized gas is
Supply passage 1 via piping 17 and electromagnetic switching valve 16
4, the pressurized gas introduced from the through hole 25 of the elastic member 24a to the exhaust hole 4 formed in the joint portion X of the piece blocks 3a and 3b, and the introduced pressurized gas passes through each joint portion X, The bubbles float in the water tank 10 as bubbles.

This state is visually observed by an inspection worker or the like from the outside of the water tank 10, and the amount of air leak of the piece blocks 3a and 3b is confirmed. When a portion with a small amount of air leak, that is, a portion with a small amount of air bubbles is found, or when the amount of air leak is abnormally large, the piece blocks 3a and 3b are determined to be defective or the piece blocks 3a and 3b. Work on the abnormal spots and remedy.

For example, if a spot with a small amount of air leak is found, the spot is gas-baked and the joint X
The work of making corrections by widening or hitting a pin or the like is performed.

In order to check the amount of air leak without submerging, a viscous liquid such as soapy water is attached to the joint portion X of the profile surface of the piece blocks 3a and 3b in advance, and the casting is performed in the same manner as described above. When pressurized gas is introduced into the exhaust hole 4 formed in the joint portion X, the pressurized gas passes through each joint portion X and viscous liquid such as soapy water attached to the joint portion X on the profile surface foams. Appears and the amount of air leak can be confirmed. The correction of the abnormal portion is performed in the same manner as described above.

As described above, in the embodiment of the present invention,
The piece blocks 3a and 3b to be inspected are hermetically sandwiched and fixed between the fixed block 12 and the movable block 13,
A pressurized gas of a predetermined pressure is supplied from a pressurized gas supply source 18, and a pressurized gas is introduced into the exhaust hole 4 of the joint X of the piece blocks 3a, 3b.
When the inspection of the air leak amount b is visually checked by leaking air bubbles in the water, water is put into the water tank 10 to visually check the air bubbles, and when the air leak amount inspection is performed in the atmosphere, A viscous liquid such as soapy water is attached to the profile surfaces of the piece blocks 3a and 3b in advance, and the viscous liquid is used to visually check the bubbles.

According to such a method, the piece block 3
By inspecting the air leak amount of a and 3b, the piece blocks 3a and 3b having an appropriate air leak amount can be easily selected, and pieces having an insufficient air leak amount are corrected to have a good appearance and dimensions. A highly accurate tire can be manufactured, and the occurrence of defective tires during vulcanization molding can be reduced.

[0033]

According to the present invention, an air leak of a tire vulcanization molding die for inspecting an air leak amount of a minute gap due to solidification shrinkage of a metal material formed at a joint portion between piece blocks as described above. An inspection device, wherein a pair of fixed blocks and a movable block that hermetically sandwich the piece block are disposed at positions facing each other, and the fixed block is an exhaust gas formed at a joint portion of the piece block. A supply passage for introducing a pressurized gas into the hole is provided, the supply passage is configured to be connected to a pressurized gas supply source, and the movable block moves a piece block to the fixed block side via a fluid pressure cylinder. Since it is configured to be pressed and fixed, the following excellent effects can be obtained. . In a puree mold, a piece block having an appropriate air leak amount can be easily selected. . Pieces with insufficient air leaks can also be corrected and remedied. . It is possible to manufacture a tire having good appearance with little overflow of rubber material and high dimensional accuracy. . The occurrence of defective tires during vulcanization molding can be reduced. . Confirmation of the necessary and sufficient leak site and leak amount can be checked in unit time for the size and the number of bubbles that float.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an air leak inspection device for a tire vulcanization molding die embodying the present invention.

FIG. 2 is a perspective view of one sector constituting a split-type tire vulcanization molding die (sector mold).

FIG. 3 is a cross-sectional view of a piece including a first piece block and a second piece block mounted on a back block.

[Explanation of symbols]

Reference Signs List 1 sector 2 back block 3 piece 3a first piece block 3b second piece block 4 exhaust hole 5 unevenness 10 air leak inspection device 11 water tank 12 fixed block 13 movable block 14 supply passage 15 pressure gauge 16 electromagnetic switching valve 17 piping 18 Pressurized gas supply source 19 Fluid pressure cylinder 20a, 20b Pressure chamber 21 Electromagnetic switching valve 22 Piping 23 Pressure supply source 24a, 24b Elastic member 25 Through hole X Cast joint

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Claims (4)

[Claims] 1. An air leak inspection device for a tire vulcanization mold for inspecting an air leak amount in a minute gap due to solidification shrinkage of a metal material formed in a joint portion between piece blocks. A pair of fixed blocks and a movable block for airtightly sandwiching the blocks are disposed at positions facing each other, and the fixed block introduces a pressurized gas into an exhaust hole formed in a joint portion of the piece block. With a supply passage,
The supply passage is configured to be connected to a pressurized gas supply source, and the movable block is configured to press and fix a piece block to the fixed block via a fluid pressure cylinder. Air leak inspection equipment for metal molds. 2. The air leak inspection device for a tire vulcanization mold according to claim 1, wherein an elastic member for sealing is attached to a piece block sandwiching surface between the fixed block and the movable block. 3. A method according to claim 1, wherein a pair of fixed block and movable block sandwiching said piece block are installed in a water tank, and an inspection of an air leak amount of said piece block is visually confirmed by leaking bubbles in water. Item 3. An air leak inspection device for a tire vulcanization mold according to item 1 or 2. 4. A viscous liquid such as soapy water is adhered to a joint portion of a profile surface of said piece block, and an air leak amount is visually checked by air bubbles of the viscous liquid in the atmosphere. 3. The air leak inspection device for a tire vulcanization molding die according to 2.