JP2005131685A - Method for producing metallic mold for tire and sipe forming edge used for this method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a metallic mold for a tire which promotes the common use of the sipe forming edge, reduces the producing cost of the metallic mold for tire and shortens the production period, and to provide a sipe forming edge used for this method. <P>SOLUTION: This method for producing a metallic mold for a tire has the steps of: planting a sipe forming edge 4 into a base mold 3 having the metallic mold shape; forming a gypsum base material 5 having the tire shape by pouring the gypsum into the base mold 3; separating the gypsum base material 5 from the base mold 3 together with the sipe forming edge 4; and casting the metallic mold 6 for tire by using the gypsum base material 5. The basic end part 4a of the sipe forming edge 4 is cast into a treading face part 6a of the metallic mold 6 for tire, and the side edge part 4b of the sipe forming edge 4 is cast into a groove-forming part 6b in the metallic mold 6 for tire. A notch part 4c is arranged at the side edge part 4b in the sipe forming edge 4 so that the cast quantity into the groove-forming part 6b in the sipe forming edge 4 becomes smaller as going toward the end side of the sipe forming edge 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a tire mold having a sipe molding blade and a sipe molding blade used therefor, and more specifically, promotes the common use of the sipe molding blade, reduces the manufacturing cost of the tire mold, and The present invention relates to a method for manufacturing a tire mold that can shorten the manufacturing period and a sipe forming blade used therefor.

  Conventionally, when manufacturing a tire mold, after a sipe molding blade is implanted in a mold having a mold shape, gypsum is poured into the mold to form a gypsum substrate having a tire shape, The tire mold is removed together with the sipe molding blade and the tire mold is cast using the gypsum base material (see, for example, Patent Document 1).

  14 (a) to 14 (d) show a conventional method for manufacturing a tire mold. First, as shown to Fig.14 (a), the tread pattern containing the groove | channel 12 is processed into the resin base material 11 corresponded to the tread part of a tire. Next, as shown in FIG. 14B, after the shape of the resin base material 11 is transferred to obtain a rubber mother die 13 having a die shape, a sipe molding blade 14 is implanted into the mother die 13. After the sipe molding blade 14 is implanted in the mother die 13 in this way, as shown in FIG. 14C, gypsum is poured into the mother die 13 to form a gypsum base material 15 having a tire shape. The material 15 is removed from the mother die 13 together with the sipe forming blade 14. Thereafter, as shown in FIG. 14 (d), the tire mold 16 is cast using the gypsum base material 15 provided with the sipe molding blade 14, and only the gypsum base material 15 is removed while leaving the sipe molding blade 14. To.

  Here, when the base end portion 14a of the sipe molding blade 14 is cast into the tread surface portion 16a of the tire mold 16, the side end portion 14b of the sipe molding blade 14 is cast into the groove forming portion 16b of the tire mold 16. By adjusting the casting amount of the sipe forming blade 14 into the groove forming portion 16b, it is possible to cope with a slight dimensional change. That is, as shown in FIG. 15, the sipe length S in the tire is changed by adjusting the casting amount B into the groove forming portion 16b of the sipe forming blade 14 with respect to the length L of the sipe forming blade 14. can do.

However, when the casting amount B is excessively small, the sipe molding blade 14 becomes unstable in the tire mold 16, and conversely, when the casting amount B is excessively large, the gypsum base material 15 is removed from the rubber mother die 13. At that time, the removal operation becomes difficult, and in some cases, the mother die 13 is easily chipped. Therefore, at present, when the sipe length S is different from the reference value by, for example, 0.5 mm or more, a new sipe forming blade is manufactured. However, according to the above criteria, it is difficult to share the sipe molding blade with various types of tire molds, and the types of sipe molding blades increase with diversification of tire molds. And when the kind of sipe molding blade increases, there exists a problem that the manufacturing cost of a tire metal mold | die will increase and the manufacture period will become long.
Japanese Patent Laid-Open No. 11-34061

  SUMMARY OF THE INVENTION An object of the present invention is to promote the common use of sipe forming blades, reduce the manufacturing cost of the tire mold, and shorten the manufacturing period, and the sipe forming blade used for the manufacturing method. Is to provide.

  In order to solve the above-described object, a tire mold manufacturing method of the present invention includes a sipe molding blade implanted in a matrix having a mold shape, and a gypsum base material having a tire shape is molded by pouring gypsum into the mold. Removing the gypsum base material from the master die together with the sipe molding blade, and casting a tire mold using the gypsum base material, and the base end portion of the sipe molding blade is a tread portion of the tire mold. In the tire mold manufacturing method in which the side end portion of the sipe forming blade is cast into the groove forming portion of the tire mold while the sipe forming blade is cast into the groove forming portion. A notch portion is provided at a side end portion of the sipe forming blade so as to decrease toward the tip side of the sipe forming blade.

  The sipe forming blade of the present invention is the sipe forming blade in which the base end portion is cast into the tread surface portion of the tire mold, and the side end portion is cast into the groove forming portion of the tire mold. A cutout portion is provided in the side end portion so that the amount cast into the forming portion decreases toward the tip end side.

  In the present invention, the notch portion is provided at the side end of the sipe forming blade so that the amount of casting into the groove forming portion of the sipe forming blade is reduced toward the tip side of the sipe forming blade. Even if the fluctuation range of the casting amount into the groove forming part is increased, the sipe forming blade becomes unstable in the tire mold, and the mother die is easily chipped when the gypsum base material is removed from the mother die. It does not occur. Therefore, the sharing of the sipe forming blade can be promoted, and the types of sipe forming blades can be reduced. As a result, the manufacturing cost of the tire mold can be reduced and the manufacturing period can be shortened.

  According to the present invention, it is possible to adjust the casting amount of the sipe forming blade into the groove forming portion in the range of 0.5 to 3.0 mm. In order to more effectively widen the adjustment range of the casting amount without causing a chipping or the like of the mother die, it is preferable to incline the section by the notch portion with respect to the height direction of the groove forming portion. The thickness of the sipe forming blade is preferably 0.3 to 1.5 mm.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  1 (a) to 1 (d) show a method for manufacturing a tire mold according to an embodiment of the present invention. First, as shown in FIG. 1A, a tread pattern including a groove 2 is processed in a resin base material 1 corresponding to a tread portion of a tire. Next, as shown in FIG. 1B, after the shape of the resin base material 1 is transferred to obtain a rubber mother die 3 having a die shape, a sipe molding blade 4 is implanted into the mother die 3. The mother die 3 is generally made of rubber, but can be made of a material such as resin. On the other hand, the thickness of the sipe forming blade 4 may be 0.3 to 1.5 mm.

  After the sipe forming blade 4 is implanted in the mother die 3, as shown in FIG. 1 (c), gypsum is poured into the mother die 3 to form a gypsum base material 5 having a tire shape. It is removed from the mother die 3 together with the molding blade 4. Thereafter, as shown in FIG. 1 (d), the tire mold 6 is cast using the gypsum base material 5 provided with the sipe molding blade 4, and only the gypsum base material 5 is removed while leaving the sipe molding blade 4. To.

  In the tire mold manufacturing method, the base end portion 4 a of the sipe molding blade 4 is cast into the tread surface portion 6 a of the tire mold 6, while the side end portion 4 b of the sipe molding blade 4 is formed into the groove of the tire mold 6. The part 6b is cast. Therefore, by adjusting the casting amount of the sipe forming blade 4 into the groove forming portion 6b, the sipe length can be changed even with the same sipe forming blade 4. Here, a cutout portion 4 c is provided in the side end portion 4 b of the sipe forming blade 4 so that the amount of casting into the groove forming portion 6 b of the sipe forming blade 4 decreases toward the tip side of the sipe forming blade 4.

  When such a notch 4c is provided, the sipe forming blade becomes unstable in the tire mold 6 even if the fluctuation range of the casting amount of the sipe forming blade 4 into the groove forming portion 6b is increased, or the plaster When the base material 5 is removed from the mother die 3, there is no inconvenience such as the mother die 3 being easily chipped. Therefore, the sharing of the sipe forming blade can be promoted, and the types of sipe forming blades can be reduced. As a result, the manufacturing cost of the tire mold can be reduced and the manufacturing period can be shortened.

  2 to 9 specifically show sipe forming blades used in the present invention. 2-9, L is the length of the sipe forming blade 4, B is the amount of casting into the groove forming portion 6b of the sipe forming blade 4, S is the sipe length of the tire, and E is the width of the groove forming portion 6b. (Groove width). In any case, the casting amount B at the base end position of the sipe forming blade 4 is preferably 0.5 to 3.0 mm. Even when the notched portion 4c is provided in the side end portion 4b of the sipe forming blade 4, the sipe forming blade 4 becomes unstable in the tire mold 6 when the casting amount B is less than 0.5 mm. If it exceeds 3.0 mm, when the gypsum base material 5 is removed from the mother die 3, the removal operation becomes difficult, and in some cases, the mother die 3 is easily chipped. The casting amount B preferably satisfies the relationship of B <0.5E with respect to the width E of the groove forming portion 6b. When B ≧ 0.5E, the mother die 3 is easily chipped when the gypsum substrate 5 is removed from the mother die 3.

  In FIG. 2, the sipe forming blade 4 has a recess 4 d on the tip side, and has a notch 4 c from the sipe bottom raised position by the recess 4 d to the tread surface position of the tire mold 6. The section formed by the notch 4c has an arc shape and is inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the radius of curvature RA of the intercept by the notch 4c satisfies the relationship of RA> C with respect to the height C of the inclined portion of the notch 4c.

  In FIG. 3, the sipe forming blade 4 has a recessed portion 4 d on the distal end side, and has a notch portion 4 c from the sipe bottom raised position by the recessed portion 4 d to the base end position of the sipe forming blade 4. The section formed by the notch 4c has an arc shape and is inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the radius of curvature RA of the intercept by the notch 4c satisfies the relationship of RA> C with respect to the height C of the inclined portion of the notch 4c.

  In FIG. 4, the sipe molding blade 4 has a recess 4 d on the tip side, and has a notch 4 c from the sipe bottom raised position by the recess 4 d to the tread surface position of the tire mold 6. A section of the notch 4c is partially arc-shaped and inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the radius of curvature RA of the intercept by the notch 4c satisfies the relationship of RA> C with respect to the height C of the inclined portion of the notch 4c.

  In FIG. 5, the sipe forming blade 4 has a recessed portion 4 d on the distal end side, and has a notch portion 4 c from the sipe bottom raising position by the recessed portion 4 d to the base end position of the sipe forming blade 4. A section of the notch 4c is partially arc-shaped and inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the radius of curvature RA of the intercept by the notch 4c satisfies the relationship of RA> C with respect to the height C of the inclined portion of the notch 4c.

  In FIG. 6, the sipe forming blade 4 has a recess 4 d on the tip side, and has a notch 4 c from the sipe bottom raised position by the recess 4 d to the tread surface position of the tire mold 6. The section by the cutout portion 4c is linear and is inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the inclination angle α with respect to the sipe length direction of the section by the notch 4c satisfies the relationship of α ≧ 45 °.

  In FIG. 7, the sipe forming blade 4 has a recessed portion 4 d on the distal end side, and has a notch portion 4 c from the sipe bottom raising position by the recessed portion 4 d to the base end position of the sipe forming blade 4. The section by the cutout portion 4c is linear and is inclined with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the inclination angle α with respect to the sipe length direction of the section by the notch 4c satisfies the relationship of α ≧ 45 °.

  In FIG. 8, the sipe molding blade 4 has a recess 4 d on the tip side, and has a notch 4 c from the sipe bottom raised position by the recess 4 d to the tread surface position of the tire mold 6. A section of the cutout portion 4c is linear with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the inclination angle α with respect to the sipe length direction of the section by the notch 4c satisfies the relationship of α ≧ 45 °.

  In FIG. 9, the sipe forming blade 4 has a recess 4 d on the distal end side, and has a notch 4 c from the sipe bottom raising position by the recess 4 d to the base end position of the sipe forming blade 4. A section of the cutout portion 4c is linear with respect to the height direction of the groove forming portion 6b. In this case, it is desirable that the inclination angle α with respect to the sipe length direction of the section by the notch 4c satisfies the relationship of α ≧ 45 °.

  Next, a method for adjusting the sipe length in the tire using the same sipe forming blade in the tire mold manufacturing method of the present invention will be described.

  FIGS. 10A to 10C show a method of adjusting the sipe length in the tire using the sipe forming blade of FIG. 10A to 10C, for example, when the length L of the sipe forming blade 4 is 12 mm, the casting amount B into the groove forming portion 6b of the sipe forming blade 4 is 3 mm, 2 mm, and 0.5 mm. By setting, the sipe length S in the tire is adjusted to 9 mm, 10 mm, and 11.5 mm.

  FIGS. 11A to 11C show a method of adjusting the sipe length in a tire using the sipe forming blade of FIG. 11A to 11C, for example, when the length L of the sipe forming blade 4 is 12 mm, the casting amount B into the groove forming portion 6b of the sipe forming blade 4 is 3 mm, 2 mm, and 0.5 mm. By setting, the sipe length S in the tire is adjusted to 9 mm, 10 mm, and 11.5 mm.

  12A to 12C show a method of adjusting the sipe length in the tire using the sipe forming blade of FIG. 12A to 12C, for example, when the length L of the sipe forming blade 4 is 12 mm, the casting amount B into the groove forming portion 6b of the sipe forming blade 4 is 3 mm, 2 mm, and 0.5 mm. By setting, the sipe length S in the tire is adjusted to 9 mm, 10 mm, and 11.5 mm.

  FIGS. 13A to 13C show a method of adjusting the sipe length in the tire using the sipe forming blade of FIG. 13A to 13C, for example, when the length L of the sipe forming blade 4 is 12 mm, the casting amount B into the groove forming portion 6b of the sipe forming blade 4 is 3 mm, 2 mm, and 0.5 mm. By setting, the sipe length S in the tire is adjusted to 9 mm, 10 mm, and 11.5 mm.

  According to the method for manufacturing a tire mold described above, the adjustment range of the casting amount B can be widened without causing a defect of the mother die. Of course, similar effects can be obtained in the case of the sipe forming blades shown in FIGS.

The present invention shows a method for manufacturing a tire mold according to an embodiment, wherein (a) is a cross-sectional view of a resin base material, (b) is a cross-sectional view of a matrix, and (c) is a cross-section of a gypsum base material. It is a figure and (d) is sectional drawing of a tire metal mold | die. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. It is a side view which shows an example of the sipe shaping blade used by this invention. The method of adjusting the sipe length in a tire using the sipe forming blade of FIG. 2 is shown, (a)-(c) is a side view which shows the sipe forming blade of the state which varied the amount of casting. The method of adjusting the sipe length in a tire using the sipe molding blade of FIG. 3 is shown, (a)-(c) is a side view which shows the sipe molding blade of the state which varied the amount of casting. The method of adjusting the sipe length in a tire using the sipe forming blade of FIG. 4 is shown, (a)-(c) is a side view which shows the sipe forming blade of the state which varied the amount of casting. The method of adjusting the sipe length in a tire using the sipe forming blade of FIG. 5 is shown, (a)-(c) is a side view which shows the sipe forming blade of the state which varied the amount of casting. A conventional tire mold manufacturing method is shown, (a) is a cross-sectional view of a resin base material, (b) is a cross-sectional view of a matrix, (c) is a cross-sectional view of a gypsum base material, d) is a sectional view of the tire mold. It is a side view which shows the conventional sipe forming blade.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin base material 2 Groove 3 Master mold 4 Sipe molding blade 4a Base end part 4b Side end part 4c Notch part 4d Recessed part 5 Gypsum base material 6 Tire mold 6a Tread part 6b Groove forming part B Casting amount

Claims (6)

A sipe molding blade is implanted into a mother mold having a mold shape, gypsum is poured into the mother mold to form a gypsum base material having a tire shape, the gypsum base material is removed from the master mold together with the sipe molding blade, and the gypsum is removed. A step of casting a tire mold using a base material, and a base end portion of the sipe molding blade is cast into a tread surface portion of the tire mold, while a side end portion of the sipe molding blade is a tire mold. In the method of manufacturing a tire mold cast into the groove forming portion of the sipe forming blade, the amount of casting of the sipe forming blade into the groove forming portion is reduced toward the tip side of the sipe forming blade. A method for manufacturing a tire mold having a notch at an end. The method for manufacturing a tire mold according to claim 1, wherein a casting amount of the sipe forming blade into a groove forming portion is adjusted in a range of 0.5 to 3.0 mm. The method for manufacturing a tire mold according to claim 1 or 2, wherein a section formed by the notch portion is inclined with respect to a height direction of the groove forming portion. The method of manufacturing a tire mold according to any one of claims 1 to 3, wherein the sipe molding blade has a thickness of 0.3 to 1.5 mm. In the sipe forming blade in which the base end portion is cast into the tread surface portion of the tire mold while the side end portion is cast into the groove forming portion of the tire mold, the casting amount into the groove forming portion is closer to the distal end side. A sipe forming blade provided with a notch at the side end so as to be reduced. The sipe forming blade according to claim 5, wherein a section formed by the notch is inclined with respect to a height direction of the groove forming portion.

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