JP4872440B2 - Method for manufacturing vulcanization mold for spike tire - Google Patents

Description

  The present invention relates to a method for producing a spike tire vulcanization mold, and more particularly, to a spike tire vulcanization mold for vulcanizing a spike tire having a large number of small holes for loading spike pins into a tread. It relates to a manufacturing method.

  A spike tire for an ice and snow road surface has a large number of small holes formed in advance for driving spike pins into the tread, and a desired number of spike pins are driven into the small holes for use.

  In such a vulcanization mold for spike tires, the mold pin for forming the spike pin driving hole may be detached when the tire is released by caulking alone, so it is implanted by screwing into the tread molding surface. Is common (see, for example, Patent Document 1).

  FIG. 4 shows a mold pin used in the vulcanization mold for spike tire disclosed in Patent Document 1. The mold pin 1 has an engagement portion 1c for engaging a hexagonal screwing tool at an end portion in the axial direction with respect to a pin portion 1a that forms a formation portion of a spike pin driving hole, and a tread forming surface 10. The screw part 1bb to be implanted in the is integrally formed.

When the screw portion 1bb is screwed into the screw hole 2 of the tread molding surface 10 while applying torque to the locking portion 1c with a screwing tool, the locking portion 1c is finally moved as shown in FIG. The tread molding surface 10 is brought into contact with and erected. Therefore, in the tire molded with this vulcanization mold, a recess corresponding to the locking portion 1c is formed around the spike pin driving hole, so that the recess not only impairs the appearance of the tread, but also spikes. It will adversely affect performance.
Japanese Patent Laid-Open No. 62-275807

  An object of the present invention is to provide a method for producing a vulcanization molding die for spike tires that enables the formation of spike tires that do not cause dents around spike pin driving holes formed in the tread.

  In order to achieve the above object, a method for manufacturing a vulcanization molding die for spike tires according to the present invention is provided for engaging a screwing tool between a pin portion which is a forming portion of a spike pin driving hole and an implanted portion having a screw portion. In a manufacturing method of a vulcanization mold for spike tires, in which a mold pin provided with a locking part is erected by screwing the screw part into a screw hole provided on a tread molding surface, The combination locking portion has a configuration in which small protrusions are arranged around the pin portion via a gap, and the mold pin is erected by screwing the screw portion into the screw hole of the tread molding surface, The small protrusion of the locking portion is removed so as to be flush with the tread molding surface.

  According to the method for manufacturing a spike tire vulcanization molding die of the present invention, the locking portion for engaging the screwing tool is formed so that the small protrusions are arranged around the pin portion with a gap therebetween, and the mold pin is treaded. After standing up on the screw hole on the molding surface, the small protrusions are removed so that they are flush with the tread molding surface, so the tires vulcanized and molded using this spike tire vulcanization mold are: A dent is not formed around the spike pin driving hole, so that the appearance of the tire is not damaged or the spike performance during running is not adversely affected.

  FIG. 1 shows an example of a mold pin used in the manufacturing method of the present invention.

  In FIG. 1, the mold pin 1 is integrally connected to a pin portion 1a, which is a molded portion of a spike pin driving hole, with an implanted portion 1b embedded in the tread molding surface of the mold at the axial end thereof. is doing. The implantation portion 1b has a rod portion 1ba having a diameter larger than that of the pin portion 1a on the pin portion 1a side, and has a configuration in which a screw portion 1bb is formed at an end portion thereof. Four small projections 1d are formed on the end face of the rod portion 1ba so as to surround the pin portion 1a via a gap, and these small projections 1d constitute a locking portion 1c for engaging a screwing tool. The rod portion 1ba of the implanted portion 1b has a diameter larger than that of the pin portion 1a, thereby dispersing the bending load applied to the mold pin 1 when the vulcanized tire is extracted from the mold, so that the durability of the mold pin 1 is increased. Improve sexiness.

  Since the small protrusions 1d form a locking part 1c for a screwing tool, it is preferable to arrange even numbers symmetrically across the axis of the pin part 1a. That is, an even number of small protrusions 1d may be arranged in a regular tetragon or a regular hexagon around the pin portion 1a.

  The shape and arrangement of the even number of small protrusions 1d are not particularly limited as long as the above-described symmetrical arrangement is made. For example, the shape and arrangement shown in FIGS. 3A and 3B are exemplified. Can do.

  The axial height h of the small protrusion 1d from the end face of the rod portion 1ba is preferably 0.5 to 2 mm, and more preferably 0.5 to 1.5 mm. When the height h is less than 0.5 mm, workability when using a screwing tool such as a socket wrench is lowered. If the height h exceeds 2 mm, it is not preferable because the labor to be removed by cutting or the like after fixing the pin is increased.

  As shown in FIG. 2, the mold pin 1 described above is erected by screwing the screw portion 1bb of the implantation portion 1b into the screw hole 2 provided in the tread molding surface 10 of the mold. The screwing is performed by engaging the screwing tool with the locking portion 1c.

  2A, after fixing the mold pin 1 to the screw hole 2 of the tread molding surface 10, the small protrusion 1d of the locking portion 1c is removed with a cutting tool or the like, and the end surface of the rod portion 1ba and the tread molding are performed. The surface 10 is flush with the surface. It is desirable that the surface after removing the small protrusions 1d be a smooth mold surface by polishing if necessary.

  In the vulcanization molding die for spike tires manufactured in this way, no step or protrusion is formed at the base of the mold pin. For this reason, the spike tire vulcanized using this spike tire vulcanization mold does not have a dent formed around the spike pin driving hole. Therefore, the appearance of the tire after the spike pin is driven into the small hole is not damaged, and the spike performance during running is not adversely affected.

The mold pin used for the manufacturing method of the vulcanization molding metal mold | die for spike tires of this invention is shown, (A) is a front view, (B) is a bottom view, (C) is a side view by X arrow of (B). It is. FIG. 1 shows a state where the mold pin of FIG. 1 is erected on the tread molding surface of a mold, wherein (A) is a cross-sectional view immediately after erection, and (B) is a cross-sectional view after removing a locking portion. (A) (B) is a bottom view equivalent to Drawing 1 (B) showing other embodiments of a mold pin used for the present invention, respectively. The conventional mold pin is shown, (A) is a front view, (B) is a bottom view. It is sectional drawing which shows the state which stood the mold pin of FIG. 4 on the tread molding surface of the metal mold | die.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mold pin 1a Pin part 1b Implanted part 1ba Rod part 1bb Screw part 1c Locking part 1d Small protrusion 2 Screw hole 10 Tread molding surface

Claims (4)

A mold pin provided with a locking portion for engaging a screwing tool between a pin portion which is a forming portion of a spike pin driving hole and an implanted portion having a screw portion, and the screw portion in a screw hole provided on a tread forming surface. In the method of manufacturing a vulcanization mold for spike tires that are screwed up and standing up,
The locking portion for engaging the tool for screwing the mold pin has a configuration in which small protrusions are arranged around the pin portion via a gap, and the screw portion is screwed into the screw hole of the tread molding surface. A method for producing a vulcanization molding die for spike tires, in which after the upright standing, the small protrusions of the locking portion are removed so as to be flush with the tread molding surface.   The vulcanization mold for spike tire according to claim 1, wherein a rod portion having a diameter larger than that of the pin portion is formed in the implanted portion, and the small protrusion is formed so as to protrude from an end surface of the rod portion. Method.   The method for manufacturing a vulcanization molding die for spike tire according to claim 1 or 2, wherein the even number of small protrusions are provided and the even number of small protrusions are arranged symmetrically with respect to the axis of the pin portion.   The method for producing a vulcanization mold for spike tire according to claim 1, 2, or 3, wherein the axial height of the small protrusion from the end face of the implanted portion is 0.5 to 2 mm.

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