JP2001150443A - Method for detecting and adjusting air leak amount of mold for vulcanizing and molding tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject method constituted so as to be capable of manufacturing a tire good in appearance by preventing the so-called light trouble of the tire generated at the time of the vulcanization of the tire by detecting whether the air leak amount of a mold for vulcanizing and molding the tire is proper or by correcting the air leak amount. SOLUTION: One ends of the exhaust holes formed at the cast joint parts X of piece blocks 3a, 3b are closed and an air supply means not shown in Fig. is connected to the other end parts thereof and the piece blocks 3a, 3b thus constituted are immersed in a water tank and air is supplied under pressure (e.g.; 0.01-0.1 MPA) from the air supply means to detect the air leak region (the position of air bubbles blown into the water tank) and air leak amount (the bubble blow-out amount in the water tank) of the piece blocks 3a, 3b to perform the detection of the air leak amount.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting and adjusting the amount of air leak of a tire vulcanization molding die, and more particularly to a puree mold (a micro-size such that a rubber material melted during tire vulcanization does not flow out). And a method for detecting and adjusting the amount of air leak of a mold having a simple vent hole and an exhaust groove.

[0002]

2. Description of the Related Art In recent years, a pureless mold (slit vent) in which a vent hole or an exhaust groove is not formed on a mold surface for the purpose of reducing the occurrence of defective products during tire vulcanization molding with a tire having an excellent appearance. Is used as a tire vulcanizing mold.

[0003] 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).

[0004] 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. In the latter invention, the base metal (aluminum) of the pattern piece is cast with a dissimilar metal (SS400), and is formed at a tire vulcanization molding temperature (160 ° C.) by a difference in linear thermal expansion coefficient. 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.

[0005]

However, the above-mentioned invention has a problem that it is difficult to secure an appropriate air vent (air leak) at an arbitrary position, and a vacuum device or the like is always required as an exhaust means. In addition, the above-described invention requires a volume necessary for generating a gap due to a difference in linear thermal expansion coefficient due to dissimilar metals, and it is difficult to secure a required gap amount at an arbitrary position. It is difficult to bleed (leak) air from the mold.

In particular, when casting a piece block, it may not be possible to secure a required amount of leak due to the pattern shape and various casting conditions. If the required amount of leak cannot be secured, The problem of so-called light failure of the tire during tire vulcanization (a phenomenon that air remains between the mold and the tire during tire vulcanization and this air dents the tire surface or causes insufficient capacity) occurs. there were.

An object of the present invention is to prevent a so-called light failure of a tire occurring at the time of tire vulcanization by detecting whether or not an air leak amount of a tire vulcanization molding die is appropriate or making a correction. It is another object of the present invention to provide a method for detecting and adjusting the amount of air leak of a tire vulcanization mold capable of producing a tire having a good appearance.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a piece block in which a piece formed by dividing a tread pattern of a tire into a plurality of sections is divided into a plurality of shots by die casting and laminated. A method for detecting and adjusting the amount of air leak of a tire vulcanization molding die formed by forming a fine gap due to solidification shrinkage of a metal material in a joint portion of the piece block, While closing one end of the exhaust hole formed in the joint, an air supply means is connected to the other end, the piece block thus configured is put in a water tank, and air at a predetermined pressure is supplied from the air supply means. Accordingly, the gist of the present invention is to detect an air leak site and an air leak amount of a piece block.

The present invention is configured as described above, and detects whether or not the Spyless mold has secured an appropriate amount of air leak at an appropriate portion, and if the air leak portion is not an appropriate portion, Correct the defective part so that the air leak part is the appropriate part, and if the air leak amount is insufficient or excessive with respect to the set value, correct the position of the exhaust hole Thus, an optimum amount of air leak is always ensured to prevent a so-called light failure of the tire occurring at the time of vulcanizing the tire, so that a tire having a good appearance can be manufactured.

[0010]

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

FIG. 1 is a perspective view of one sector constituting a split-type tire vulcanization molding die (sector mold) for carrying out the air leak amount detection and adjustment method of the present invention. One sector 1 is configured by mounting a plurality of pieces 3 having irregularities 2 corresponding to at least a profile surface of a tread portion of a product tire on a back block 4 adjacent to each other.

As shown in FIGS. 2 and 3, the plurality of pieces 3 mounted on the back block 4 are formed by dividing a tread pattern in the tire circumferential direction into a plurality of sections at a constant pitch or an arbitrary pitch, and dividing the tread pattern into a single piece. Configure and
Each piece alone is divided into a plurality of shots (two shots in this embodiment, but the number of times is not particularly limited) by die casting to form a first piece block 3a and a second piece block 3b. It is constructed by casting and laminating.

Then, fine gaps are formed in the joint portion X of the cast metal material (the first piece 3a and the second piece 3b) by the plurality of shots due to solidification shrinkage of the metal material. The fine gap formed by the solidification shrinkage of the second shot is 0.005 to 0.06 mm, preferably 0.02 mm. Further, an exhaust hole 5 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.

The method of detecting and adjusting the amount of air leak of the tire vulcanization molding die configured as described above is performed by the following method.

The piece block 3 constructed as described above
One end of an exhaust hole formed in the joint portion X of a and 3b is closed, and air supply means (not shown) is connected to the other end, and the piece blocks 3a and 3b thus configured are put in a water tank and immersed. Air is supplied from the air supply means at a predetermined pressure (for example, 0.01 MPa to 0.1 MPa), and the air leak portions of the piece blocks 3a and 3b (the positions of the air bubbles blown into the water tank) and the amount of air leak (in the water tank) The amount of air leaks is detected by detecting the amount of foam blown out.

In the above detection method, when a specified non-leak portion is found in the detection of the air leak portion, marking is performed on the specified portion, and the air leak is detected by a heating means such as a gas burner. The non-conforming defective portion is baked, and heat is applied to the piece blocks 3a and 3b by a heat shock, and the gap is formed by exfoliating between the closely-joined joints X to secure a predetermined amount of air leak and to reduce the amount of air leak. The adjustment of.

If it is determined that the amount of air leak at the joint X is insufficient with respect to the set value (actually, it is detected based on the amount of bubbles in the water tank), The exhaust holes 5 are corrected so as to be provided close to the profile surfaces of the piece blocks 3a and 3b. Further, when it is determined that the air leak amount of the joint portion X is excessive with respect to the set value, the exhaust hole 5 provided in the joint portion X is determined.
Is provided so as to be provided away from the profile surfaces of the piece blocks 3a and 3b. By applying the correcting means as described above, an appropriate amount of air leak can be secured.

According to the present invention, the method described above detects whether or not the Supless mold has secured an appropriate amount of air leak at an appropriate portion. Correct the defective part so that the air leak part is the appropriate part.If the air leak amount is insufficient or excessive with respect to the set value, correct the position of the exhaust hole. In addition, a tire having a good appearance can be manufactured by always securing an optimum amount of air leak to prevent a so-called light failure of the tire occurring during tire vulcanization.

[0019]

As described above, according to the present invention, a piece block is formed by dividing a plurality of pieces of a tread pattern of a tire into a plurality of shots by die casting to form a piece block. A method for detecting and adjusting the amount of air leak of a tire vulcanization molding die formed by forming a fine gap due to solidification shrinkage of a metal material in a joint portion of a block, wherein the air leak amount is formed in a joint portion of the piece block. While closing one end of the exhaust hole, an air supply means is connected to the other end, the piece block thus configured is put into a water tank, and air at a predetermined pressure is supplied from the air supply means, and the air in the piece block is By detecting the leak area and air leak amount or correcting the defective part, it always secures the optimum air leak amount and generates during tire vulcanization. To prevent the so-called light failure at the tire,
There is an effect that a tire having a good appearance can be manufactured, and a defective piece block can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of one sector constituting a split-type tire vulcanization molding die (sector mold) for carrying out the air leak amount detection and adjustment method of the present invention.

FIG. 2 is a sectional view of a piece block integrated with casting.

FIG. 3 is a plan view of a piece block integrated with casting.

[Description of Signs] 1 sector 1A sector mold 1B upper and lower two-part mold 2 unevenness 3 pieces 3a first piece block 3b second piece block 4 back block 5 exhaust hole X joint

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

Claims (5)

[Claims] 1. A piece block formed by dividing a tread pattern of a tire into a plurality of sections and dividing it into a plurality of shots by die casting to form a piece block. A method for detecting and adjusting an air leak amount of a tire vulcanization molding die formed by forming a minute gap due to solidification shrinkage of a material, wherein one end of an exhaust hole formed in a joint portion of the piece block is closed. , Connect the air supply means to the other end,
The thus constructed piece block is placed in a water tank, and air at a predetermined pressure is supplied from the air supply means to detect an air leak portion of the piece block and an air leak amount of a tire vulcanization mold for detecting an air leak amount. Detection and adjustment method. 2. When detecting the air leak portion, a heat shock is applied to a specified non-leak portion by the heat of a heating means, and a gap is formed by separating the closely-joined joints to form a predetermined air. The method for detecting and adjusting an air leak amount of a mold for vulcanizing a tire according to claim 1, wherein the leak amount is secured. 3. When the air leak amount of the joint is determined to be insufficient with respect to a set value, an exhaust hole provided in the joint is provided close to the profile surface side of the piece block. A method for detecting and adjusting the amount of air leak of the mold for vulcanizing a tire according to claim 1. 4. An exhaust hole provided in the joint portion is provided away from a profile surface of the piece block when it is determined that an air leak amount of the joint portion is excessive with respect to a set value. 4. The method for detecting and adjusting the amount of air leak of a mold for vulcanization molding of a tire according to the above. 5. An air supply pressure of said air supply means is 0.01 MPa to 0.1 MPa.
4. The method for detecting and adjusting the amount of air leak of a mold for vulcanization molding of a tire according to the above.