JP4730953B2 - Cleaning method of tire mold - Google Patents

Description

  The present invention relates to a method for cleaning a tire molding die, and more particularly, to a method for cleaning a tire molding die with blast powder without causing clogging of vent holes.

  The raw tire is vulcanized and molded by a tire molding die. When vulcanization molding is repeated, a mold release agent and other additives may adhere to the tire molding surface. Therefore, it is necessary to clean the tire molding surface at regular intervals in the tire manufacturing process. For example, Patent Document 1 discloses a method for cleaning a tire molding surface by spraying blast powder onto the tire molding surface.

JP 2001-232642 (paragraph 0010)

  In the tire vulcanization molding process, air accumulates in the mold and is not discharged, which may cause manufacturing defects. Therefore, a vent hole called a vent hole is provided to discharge air. In the method of cleaning a mold having a vent hole using blast powder, the blown blast powder may be clogged in the vent hole. Therefore, it is necessary to remove clogged blast powder, which causes an increase in manufacturing cost.

  As a cleaning method in which clogging does not occur in the vent hole, a method using dry ice beads instead of blast powder, a cleaning method using laser or plasma, and the like can be mentioned. These methods are more expensive than cleaning methods using blast powder, and are not methods for reducing manufacturing costs.

  Accordingly, an object of the present invention is to provide a method for cleaning a mold for tire molding that is inexpensive and does not cause clogging of vent holes.

  In the present invention, air flow is applied to the air discharge surface of a mold for molding a tire provided with a vent hole, and blast powder is applied to the tire molding surface in a state where the air flow flows out to the tire molding surface side through the vent hole. A method for cleaning a tire molding die, characterized in that the tire molding surface is cleaned by spraying.

  When an air flow is applied to the air discharge surface of the tire molding die, an air flow is generated toward the tire molding surface through the vent hole. Since the air flow prevents the blast powder from entering the vent hole when the mold is cleaned, clogging of bentol does not occur. In addition, since the mold can be cleaned with normal blast powder, the cleaning cost is not increased.

The present invention is such that the air discharge surface of the tire molding die provided with a vent hole is opposed to the discharge surface of the air delivery device, and a frame is disposed between the air discharge surface and the delivery surface,
A closed space is formed by the air discharge surface, the frame, and the delivery surface,
In the state where the air flow is sent into the closed space, the pressure higher than the atmospheric pressure is maintained, and the air flow is discharged to the tire molding surface side through the vent hole, the blast powder is sprayed on the tire molding surface to form the tire. A method for cleaning a mold for molding a tire, wherein the surface is cleaned.

  For example, when using an air delivery device, the air discharge surface and the delivery surface of the air delivery device are opposed to each other, and a frame body is disposed between both to form a closed space. Since the air flow can be sent out to the closed space and the air flow can flow out to the tire molding surface side through the vent hole more efficiently, the efficiency of preventing clogging can be increased.

  The present invention is a tire molding die cleaning method, wherein the pressure in the closed space is 0.1 to 2.0 MPa.

The size of the pressure is small when the total cross-sectional area of the vent hole is small, and when the total cross-sectional area of the vent hole is large, air is blown out locally due to pressure loss. Although it is preferable, if the pressure in the closed space is too small, the flow velocity of the air flow is small, and it may not be possible to prevent the blast powder from entering the vent hole. On the other hand, if the pressure in the closed space is too large, the air flow becomes turbulent and the blast powder does not hit the tire molding surface in the vicinity of the vent hole, resulting in insufficient cleaning.
Therefore, the pressure in the closed space is preferably 0.1 to 2.0 MPa.

  If the air delivery device is provided with a frame in advance on the delivery surface, the frame can be brought into contact with the air discharge surface of the mold to form a closed space, and the mold can be efficiently cleaned. A sheet-like frame made of rubber can be suitably used.

  Hereinafter, embodiments of a method for cleaning a tire molding die according to the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a mold showing a cleaning method according to the present invention. The mold 1 is a mold called a side plate that vulcanizes and molds a side portion of a tire. A vent hole 2 penetrating from the tire molding surface 1a to the air discharge surface 1b is provided. At the time of vulcanization molding, the air accumulated in the mold 1 passes through the vent hole 2 and is discharged to the air discharge surface 1b side.

  First, the air discharge surface 1b of the mold 1 and the delivery surface 12a of the air delivery device 12 are opposed to each other, and the frame 11 is disposed between the air delivery surface 1b and the delivery surface 12a. Therefore, the closed space 20 is formed by the air discharge surface 1b, the frame body 11, and the delivery surface 12a. In addition, as shown in FIG. 2, the vent hole 2 exists in the frame 11 in the state which enclosed a part of air discharge surface 1b.

    By sending the air flow 21 into the closed space 20 by the air delivery device 12, the inside of the closed space 20 is maintained at a pressure higher than the atmospheric pressure. In this state, the tire molding surface 1a is cleaned by spraying blast powder by a known method. Since the pressure in the closed space 20 is higher than the atmospheric pressure, the air flow 21 continues to flow out to the tire molding surface 1 a side through the vent hole 2. The blast powder is prevented from entering the vent hole 2 by the air flow 21 that flows out. As a result, the tire molding surface 1a can be cleaned without causing the vent hole 2 to be clogged.

  The pressure in the closed space 20 is preferably 0.1 to 2.0 MPa. If it is less than 0.1 MPa, the flow rate of the air flow 21 is small, so that blast powder may enter the vent hole 2 and clogging is likely to occur. When the pressure exceeds 2.0 MPa, the flow velocity of the air flow 21 flowing out increases, and a turbulent flow is generated in the vicinity of the vent hole 2 so that a portion where the blast powder does not hit is formed. Therefore, the tire molding surface 1a may not be sufficiently cleaned.

  In order to ensure airtightness in the closed space 20, the frame body 11 is preferably made of an elastic material. For example, a sheet-like frame made of rubber can be suitably used. Alternatively, the closed space 20 may be formed by abutting the air delivery device 12 provided with the frame 11 on the delivery surface 12a in advance with the air discharge surface 1b of the mold 1.

  The mold to be cleaned is not limited to the side plate, but may be one of a sector ring forming a tread and a two-piece mold. In particular, since the diameter of the vent hole provided in the side portion of the tire is smaller than that of the vent hole provided in the tread portion, the cleaning method is preferably used for a mold for forming the side portion.

It is metal mold | die sectional drawing which shows the washing | cleaning method concerning this invention. It is a figure which shows the air discharge surface of a frame and a metal mold | die.

Explanation of symbols

1 Mold 2 Bent piece 11 Frame 12 Air delivery device

Claims (3)

  Applying an air flow to the air discharge surface of a mold for molding a tire having a vent hole, and blowing the blast powder onto the tire molding surface with the air flow flowing out to the tire molding surface through the vent hole A method for cleaning a mold for molding a tire, wherein the surface is cleaned. The air discharge surface of the mold for molding a tire provided with a vent hole is opposed to the discharge surface of the air delivery device, and a frame is disposed between the air discharge surface and the delivery surface,
A closed space is formed by the air discharge surface, the frame, and the delivery surface,
In the state where the air flow is sent into the closed space, the pressure higher than the atmospheric pressure is maintained, and the air flow is discharged to the tire molding surface side through the vent hole, the blast powder is sprayed on the tire molding surface to form the tire. A method for cleaning a mold for molding a tire, wherein the surface is cleaned.   The method of cleaning a tire molding die according to claim 2, wherein the pressure in the closed space is 0.1 to 2.0 MPa.

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