JP2005280316A - Tire mold and its manufacturing method, and tire molded by using tire mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire mold and its manufacturing method, which can improve plaster molding flow, can enhance durability of a blast in blast treatment of an inner surface of the mold and can enhance an appearance of a tire, in the manufacture of the mold, and the tire which is molded by using the tire mold. <P>SOLUTION: The first embodiment is formed in such a manner that a butt end surface Wa of a sipe forming blade Wx covers a butt end surface Wb of a cast part Wx, when a butt part 1a, where the sipe forming blade W and the cast part Wx butt against each other, is seen from the side of a molding surface Z of the mold, In the embodiment, an angle between the butt end surfaces Wa and Wb of the part 1a, where the sipe forming blade W and the cast part Wx butt against each other, is set as α, and an angle between the molding surface Z of the cast part Wx and the butt end surface Wb of the cast part Wx, is set at an obtuse angle, and preferably set to be in the range of 120-150°. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tire molding die, a method of manufacturing the die, a tire molded by the tire molding die, and more particularly, to a tire molding surface corresponding to a tire tread surface portion on a part of a sipe molding blade. When manufacturing tire molding molds with sipe casting parts, the gypsum casting hot water is improved, shot blasting durability is improved during shot blasting on the mold inner surface, and the appearance of the tire after molding TECHNICAL FIELD The present invention relates to a tire molding die with improved rim, a method for manufacturing the die, and a tire molded with the tire molding die.

  In general, as a process for manufacturing a mold for forming a tire, for example, as shown in FIGS. 9A to 9E, first, a narrow groove of a tire is formed on a master resin mold A formed corresponding to the form of a tire tread surface portion. A sipe molding blade W made of a metal material such as stainless steel is formed, and an engagement groove G of the sipe molding blade W is formed in a rubber molding die B transferred using the master resin die A.

  Then, after attaching the sipe molding blade W to the engagement groove G, a gypsum mold C in which the gypsum material is poured into the rubber mold B to embed the sipe molding blade W is molded, and this gypsum mold C is used. A tire molding die D such as an aluminum alloy is molded (for example, see Patent Document 1).

  By the way, at the time of casting the tire molding die as described above, due to the difference in thermal expansion due to the difference in material between the sipe molding blade W made of a metal material and the gypsum mold C, a stepped casting and a depression as shown in FIG. Such a problem that the plaster mold cracks Q are likely to occur.

In particular, due to the design of the tire tread surface, the sipe forming blade W arranged up to the profile shoulder end often has a long overall length. As countermeasures against this, as shown in FIGS. 6, 8, and 9a to 9e, As described above, a part of the sipe forming blade W is used as a casting portion Wx, and the thermal expansion amount of the sipe forming blade W is reduced. However, the boundary line S between the sipe forming blade W and the cast-out portion Wx formed by such a process is straight with respect to the molding surface Z of the tire molding die D as shown in FIGS. Because of the state, there were the following problems.
(1) Since the shape of the sipe cast portion of the gypsum mold C is a narrow groove K as shown in FIG. 6, it is difficult for molten aluminum to flow to the tip of the groove bottom, which tends to cause poor casting hot water.
(2) When the molding surface Z is blasted by shot blasting or the like after casting the tire molding die, the angle of the casting portion Wx abutted against the sipe molding blade W is blasted as shown in FIG. Since it is in an exposed state with respect to the irradiation direction P, it is easy to wear out, and a wedge-shaped gap Sa is generated at the abutting portion of the boundary portion between the sipe forming blade W and the cast-out portion Wx, and the tire is formed by this gap Sa. Later, burrs occur. As a result, the sipe grooves that should be continuous originally appear to be discontinuous, which causes a poor appearance of the tire.

  This invention pays attention to such conventional problems, and improves the gypsum casting hot water when manufacturing a molding die by improving the end face shape of the butt portion at the boundary between the sipe forming blade and the casting portion. In addition, the durability of the blast at the time of blasting the inner surface of the mold can be improved, and further, the appearance of the tire can be improved, the mold for manufacturing the mold, the method for manufacturing the mold, and the mold for molding the tire. The object is to provide a tire.

  In order to achieve the above object, the tire molding die according to the present invention has a sipe molding blade butt when the butt portion between the sipe molding blade and the casting portion is viewed from the molding surface side of the molding die. The gist is that the end surface is formed so as to cover the butt end surface of the casting portion. Here, the angle of the butt end surface at the butt portion between the sipe forming blade and the cast-out portion is an obtuse angle, preferably 120 ° to 150 °, formed by the molding surface of the cast-out portion and the butt end surface of the cast-out portion. In addition, the shape of the butt end surface at the butt portion between the sipe forming blade and the casting portion is formed by any one of a straight shape, a step shape, and a wave shape.

  Further, the tire molding die manufacturing method of the present invention, when forming the gypsum mold, in the engagement groove of the sipe molding blade of the rubber molding die, the butt end surface of the casting portion when viewed from the molding surface side When forming a gypsum mold by arranging a sipe molding blade formed so as to cover, when sipe molding blade is embedded in a gypsum mold at the tip side and a mold for molding a tire is molded using this gypsum mold Further, the gist of the invention is that the sipe forming blade is embedded integrally so as to cover the abutting end face of the casting portion.

  Furthermore, the tire molded by the tire molding die of the present invention is a tire in which a narrow groove continuous in the tire tread surface portion is formed by tire vulcanization molding using the tire molding die as described above. .

  Thus, when the butt portion between the sipe molding blade and the casting portion is viewed from the molding surface side of the molding die, the butt end surface of the sipe molding blade is formed so as to cover the butt end surface of the casting portion. When manufacturing a molding die, it is possible to improve the gypsum casting hot water, improve the durability of blasting during blasting of the inner surface of the die, and further improve the appearance of the tire.

  Since the present invention has improved the end face shape of the abutting portion at the boundary between the sipe forming blade and the casting portion as described above, when casting a molding die, the gypsum casting hot water is improved and the inner surface of the die is improved. The durability of blasting during blasting can be improved, and the appearance of the tire can be further improved.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
Note that the same components as those in the conventional example are denoted by the same reference numerals and description thereof is omitted.

  FIG. 1 shows a metal sipe forming blade W having a thickness of 0.2 to 2.0 mm for forming a narrow groove of a tire on a molding surface Z of a molding die showing a first embodiment of the present invention, and the sipe 1 shows a partially enlarged cross-sectional view of a tire molding die D in which a casting portion Wx is formed by abutting against a part of a molding blade W, and the first embodiment includes a sipe molding blade W and a casting portion Wx. When the butting portion 1a is viewed from the molding surface Z side of the molding die, the butting end surface Wa of the sipe molding blade Wx is formed so as to cover the butting end surface Wb of the casting portion Wx.

  That is, in this embodiment, as the angle α of the abutting end surfaces Wa and Wb in the abutting portion 1a between the sipe forming blade W and the casting portion Wx, the abutting end surface of the molding surface Z of the casting portion Wx and the casting portion Wx. The angle formed with Wb is set to an obtuse angle, and preferably set to 120 ° to 150 °.

  When the angle α is less than 120 °, a casting hot water defect at the boundary between the sipe part and the casting part tends to occur in the sipe casting part ridge line. When the angle exceeds 150 °, the sipe tip has an acute angle at the boundary between the sipe ridge line and the cast-out portion, and the strength of the tip portion is reduced. Furthermore, there is a possibility of deformation during the punching operation during sipe production or during finishing (barrel polishing for deburring).

  With this configuration, the butt end surface Wa of the sipe forming blade Wx inevitably covers the butt end surface Wb of the casting part Wx.

  Further, the shape of the abutting end faces Wa and Wb in the abutting portion 1a between the sipe forming blade W and the cast-out portion Wx is linear 1a as shown in FIG. 1, or stepped 1b as shown in FIG. As shown in FIG. 3, it is configured by any one of the wave shapes 1c.

  Further, in the case of manufacturing the tire molding die as described above, it is performed by the same method as that shown in FIGS. 9A to 9E, and in the embodiment of the present invention, the gypsum mold C is formed. In this case, the sipe forming blade W formed so as to cover the butted end faces Wa and Wb of the casting portion Wx when viewed from the molding surface Z side is arranged in the engagement groove G of the sipe forming blade W of the rubber mold B. When the gypsum mold D is formed, the tip side of the sipe molding blade W is embedded in the gypsum mold C.

  When the tire molding die D is molded using the gypsum mold C, the sipe molding blade W is embedded so as to cover the butted end surfaces Wa and Wb of the casting portion Wx.

  In addition, a tire molded using such a mold for molding a tire can form continuous fine grooves having a good appearance on the tire tread portion.

  As described above, in the present invention, since the end face shape of the abutting portion 1a at the boundary portion between the sipe forming blade W and the casting portion Wx has been improved as described above, when the molding die D is cast, gypsum casting As shown in FIG. 4, the sipe forming blade W is formed so as to cover the butt end surfaces Wa and Wb of the casting portion Wx when blasting the inner surface of the mold from the direction of arrow P as shown in FIG. Therefore, the durability of blasting can be improved.

1 is a partially enlarged cross-sectional view of a molding die showing a first embodiment of the present invention. It is a partially expanded sectional view of the molding die showing a second embodiment of the present invention. It is a partially expanded sectional view of the metal mold | die which shows 3rd Embodiment of this invention. It is explanatory drawing of the blast process in the butt | matching part of the sipe forming blade of this invention, and a casting part. It is explanatory drawing of the blast process in the butt | matching part of the conventional sipe forming blade and a casting part. It is a partial top view of the metal mold | die which formed the conventional sipe molding blade and the casting part. It is a partial sectional view of a gypsum mold C in which a conventional sipe forming blade is formed. It is a partial sectional view of a gypsum mold C in which a conventional sipe forming blade and a casting part are formed. (A)-(e) is explanatory drawing of the manufacturing process of the conventional metal mold | die for tire shaping | molding.

Explanation of symbols

A Master resin mold B Rubber molding mold C Plaster mold D Tire molding mold G Engagement groove W Sipe molding blade Wx Casting part Q Gypsum mold crack K Narrow groove Z Molding surface S Boundary line Sa Clearance P Blast irradiation direction 1a 〜1c Butt part Wa Butt end face Wb Butt end face

Claims (5)

In a metal sipe molding blade for forming a narrow groove of a tire on a molding surface of the molding die, and a tire molding die in which a casting portion is formed by abutting a part of the sipe molding blade,
When the butt portion between the sipe forming blade and the casting portion is viewed from the molding surface side of the molding die, the butt end surface of the sipe molding blade is formed so as to cover the butt end surface of the casting portion. Tire mold. 2. The tire molding metal according to claim 1, wherein an angle of a butt end surface at a butt portion between the sipe forming blade and the cast-out portion is an obtuse angle formed by a molding surface of the cast-out portion and a butt end surface of the cast-out portion. Type. 3. The tire molding die according to claim 1, wherein a shape of a butt end surface at a butt portion between the sipe molding blade and the casting portion is any one of a straight shape, a step shape, and a wave shape. A rubber molding die in which a sipe molding blade for forming a narrow groove of a tire is disposed in a master resin mold formed corresponding to the form of the tire tread surface, and a cast-out portion is formed and transferred by this master resin mold An engaging groove and a casting part of a sipe forming blade are formed on the sipe forming blade, and after mounting the sipe forming blade into the engaging groove, a gypsum material is poured into the rubber mold to embed the sipe forming blade and a casting part. In the tire mold manufacturing method for forming a mold for molding a tire using the gypsum mold formed with the gypsum mold,
When forming the gypsum mold, a sipe molding blade formed so as to cover the abutting end surface of the casting portion when viewed from the molding surface side is disposed in the engagement groove of the sipe molding blade of the rubber mold. When forming a mold, the tip of the sipe forming blade is embedded in a gypsum mold, and when forming a mold for molding a tire using this gypsum mold, the sipe forming blade uses the butt end surface of the casting portion. A method for manufacturing a tire molding die, wherein the tire molding die is embedded so as to cover it. A tire molded by a tire molding die formed by forming a continuous groove on a tire tread surface portion by tire vulcanization molding using the tire molding die according to claim 1.

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