Method for manufacturing a mold for tire manufacturing

Abstract

To provide a method for manufacturing a metallic mold for manufacturing a tire, the metallic mold comprising a void molding material which is excellent in accuracy of the positioning thereof.SOLUTION: A metallic mold 22 for manufacturing a tire comprises a metallic mold main body 40 for molding a tread surface, and a void molding material 42 which is composed of a material different from the metallic mold main body 40 and molds a void in the tread surface. The void molding material 42 is mounted to a rubber mold 50 while supported using a support member 66. Gypsum is flowed into the rubber mold 50 while the void molding material 42 is supported, and a gypsum casting mold 52 fixed with the void molding material 42 is manufactured. The metallic mold main body 40 to which the void molding material 42 is inserted is obtained by flowing metal into the gypsum casting mold 52.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION An embodiment of the present invention relates to a method for manufacturing a tire building mold. [Background technology]

[0002] Molds for manufacturing tire tread surfaces are generally produced by pouring metal into a plaster mold for casting. Furthermore, in molds for manufacturing tires having voids such as sipes in the tread surface, the void molding material for molding the voids may be made of a material different from the mold body. For example, the mold body is made of a soft metal such as aluminum for lightness, while the void molding material is made of an iron-based metal such as stainless steel for strength and other reasons. In this case, the void molding material is cast into the mold body when the mold body is cast.

[0003] The following method is known as a method for producing a mold having such a void molding material. The void molding material is attached to a rubber mold, and plaster is poured into the rubber mold to produce a plaster mold in which the void molding material is fixed. Next, the rubber mold is removed, and metal is poured into the plaster mold to cast the mold body. Thereafter, the plaster mold is removed, yielding a mold in which the void molding material is cast inside (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-58458 Summary of the Invention [Problem to be solved by the invention]

[0005] When attaching the void molding material to a rubber mold to prepare a plaster mold as described above, it is difficult to maintain the metal void molding material in a stable position relative to the rubber mold. If the position of the void molding material is not stable within the rubber mold, the positioning accuracy of the void molding material in the plaster mold is impaired, which in turn affects the positioning accuracy of the void molding material in the tire manufacturing mold. In recent years, in order to improve tire performance, it has become common to adopt a narrow and deep groove shape on the tread surface that is wider than a sipe. When molding such grooves using void molding material, the weight of the void molding material makes it even more difficult to stabilize the position of the void molding material in the rubber mold compared to when molding sipes, and the positioning accuracy of the void molding material in the plaster mold is impaired.

[0006] In view of the above, an object of an embodiment of the present invention is to provide a method for manufacturing a tire manufacturing mold that is excellent in positioning accuracy of a void molding material. [Means for solving the problem]

[0007] An embodiment of the present invention is a method for manufacturing a tire manufacturing mold including a mold body for molding a tread surface and a void molding material made of a different material from the mold body for molding voids in the tread surface. The manufacturing method includes: attaching the void molding material to a rubber mold together with a support member while the void molding material is supported by the support member; pouring plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and pouring metal into the plaster mold to cast the mold body with the void molding material cast inside.

[0008] In one embodiment, the support member may be attached to the rubber mold in a state where it protrudes from the molding surface of the rubber mold, and the plaster mold may be prepared in a state where the protruding portion is embedded, and after the mold body is cast, the part of the support member protruding from the tread molding surface of the mold body may be removed. In this case, the support member may have a breaking portion for removing the part, and after the mold body is cast, the support member may be broken at the breaking portion to remove the part.

[0009] In one embodiment, the support member may be attached to the rubber mold without protruding from the molding surface of the rubber mold. In this case, the support member may support the void molding material in a range of 70 to 95% in the depth direction from the deepest part of the portion of the void molding material embedded in the rubber mold.

[0010] In one embodiment, the support member may be made of the same material as the mold body.

[0011] In one embodiment, a plurality of the void molding materials may be provided in the mold body, and each void molding material may be supported by a plurality of the support members.

[0012] In one embodiment, the support member may be shaped to be connected across both sides in the width direction across the deepest part of the portion of the void molding material embedded in the rubber mold. [Effects of the Invention]

[0013] In an embodiment of the present invention, a plaster mold is made by pouring plaster into a rubber mold while the void molding material is supported on the rubber mold using a support member, thereby stabilizing the posture of the void molding material in the rubber mold and improving the positioning accuracy of the void molding material in the plaster mold. [Brief explanation of the drawings]

[0014] [Figure 1] Half cross-section of tire vulcanizing equipment [Figure 2] Schematic diagram for explaining a manufacturing process of a tire manufacturing mold according to one embodiment. [Figure 3] A perspective view of a master mold in the first embodiment [Figure 4] 1 is a perspective view showing a process for producing a rubber mold according to a first embodiment; [Figure 5] 1 is a perspective view of a rubber mold according to a first embodiment; [Figure 6] FIG. 1 is a perspective view showing a process for producing a plaster mold in the first embodiment; [Figure 7] 1 is a perspective view of a gypsum mold according to a first embodiment; [Figure 8] 1 is a perspective view showing a casting process of a die body in the first embodiment; [Figure 9] FIG. 10 is a perspective view showing a step of removing the tire manufacturing mold in the first embodiment. [Figure 10] 1A and 1B are cross-sectional views of the void molding material and its surroundings in each manufacturing process of a tire manufacturing mold according to the first embodiment; [Figure 11] 1 is an enlarged perspective view of a main part of a gypsum mold according to a first embodiment; [Figure 12] 10A and 10B are cross-sectional views of the void molding material and its surroundings in each manufacturing process of a tire manufacturing mold according to a second embodiment. [Figure 13] An enlarged perspective view of a main part of a gypsum mold in a second embodiment. [Figure 14] An enlarged perspective view of a main part of a gypsum mold in a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0016] 1 shows an example of a tire vulcanizing apparatus 10 for vulcanizing and molding a pneumatic tire. The tire vulcanizing apparatus 10 includes a vulcanizing mold 12, a container 14 to which the vulcanizing mold 12 is attached, and a bladder 16, and vulcanizes an unvulcanized tire while molding it into a predetermined shape.

[0017] The vulcanization mold 12 includes a pair of upper and lower side plates 18, 20, a plurality of sectors 22 divided in the circumferential direction, and a pair of upper and lower bead rings 24, 26, and molds the outer surface of the tire T. The sectors 22 are molds for molding the tread surface T1 of the tire T, and are divided into a plurality of sectors in the tire circumferential direction and are provided so as to be able to expand and contract in the tire radial direction.

[0018] The container 14 includes a plurality of segments 28 that hold the sectors 22, a jacket ring 30 that moves the segments 28 in the tire radial direction, and a pair of upper and lower mounting plates 32, 34. The jacket ring 30 moves up and down relative to the segments 28, thereby moving the segments 28 in the tire radial direction, thereby enabling the sectors 22 to expand and contract in the tire radial direction. The upper mounting plate 32 is configured to move up and down relative to the lower mounting plate 34 by a lifting device (not shown).

[0019] The bladder 16 is made of a toroidal elastic rubber body that can expand and contract, and is disposed on the inner surface side of the tire T. The bladder 16 is inflated by the supply of pressurized gas, thereby pressurizing the tire T from the inside.

[0020] Hereinafter, a method for manufacturing the sectors 22, which are molds for molding the tread surface T1 (i.e., the decorative surface of the tread) of the tire T, will be described. Note that the side plates 18, 20 and the bead rings 24, 24, which are molds other than the sectors 22, can be manufactured according to conventional methods. In the following description, the sectors 22 will be referred to as the "tire manufacturing mold 22" or simply as the "mold 22."

[0021] The mold 22 includes a mold body 40 for molding the tread surface T1 and a void molding material 42 for molding voids in the tread surface T1 (see FIG. 9). Usually, a plurality of void molding materials 42 are cast-in into the mold body 40. Cast-in generally refers to pouring molten metal around a different material to obtain a cast product integrated with the main body, and in this case refers to pouring molten metal using the void molding material 42 as an insert to obtain a mold 22 in which the void molding material 42 is integrated into the mold body 40.

[0022] The mold body 40 is made of a soft metal such as aluminum or an aluminum alloy. The mold body 40 has a tread molding surface 40A for molding the tread surface T1. The tread molding surface 40A is provided with ribs 44 for molding main grooves, i.e., circumferential grooves (reference numeral T2 in FIG. 1), on the tread surface T1. The ribs 44 are convex stripes that protrude from the tread molding surface 40A and extend in the tire circumferential direction, and are formed integrally with the mold body 40.

[0023] The void molding material 42 is made of a material different from that of the mold body 40, and is preferably formed of an iron-based metal such as stainless steel from the standpoint of strength, etc. Examples of voids molded by the void molding material 42 include various recesses provided on the tread surface T1, but preferably include groove-shaped recesses such as sipes and narrow grooves. Here, a sipe is a cut with a groove width of 2 mm or less and is also called a kerf. A narrow groove is a groove with a narrower groove width than a main groove, for example, a groove with a groove width of 5 mm or less. The sipes and narrow grooves may extend in the tire circumferential direction or the tire width direction. The portion of the void molding material 42 that protrudes from the mold body 40 and molds the voids is called a molding portion 42A, and the portion that is embedded in the mold body 40 is called an embedded portion 42B.

[0024] When a groove-shaped depression is to be formed, the void molding material 42 has a plate shape. In the example shown in Fig. 9, the void molding material 42 has a flat plate shape, but the shape of the void molding material 42 is not limited to a flat plate shape. For example, when the depression to be formed has a curved linear shape in a plan view (opening shape), the void molding material 42 may have a curved plate shape. When the depression to be formed has a linear shape with a bent portion in a plan view, the void molding material 42 may have a plate shape with a bent portion. When the depression to be formed has a wave-shaped shape in a plan view, the void molding material 42 may have a corrugated plate shape.

[0025] FIG. 2 shows an outline of a method for manufacturing the mold 22, which includes the following steps. Step 1: Creating a prototype 46 (see Figure 2(A)) Step 2: Attaching the mounting hole molding material 48 to the master mold 46 (see Figure 2(B)) Step 3: Making the rubber mold 50 (see Figures 2(C) and (D)) Step 4: Attaching the void molding material 42 to the rubber mold 50 (see Figure 2(E)) Step 5. Preparation of plaster mold 52 (see Figure 2(F)) Step 6: Casting the mold 22 (see Figures 2(G) to (I)).

[0026] 2(A), a master mold 46 is produced. The master mold 46 is a mold (tire model) having the same shape as the tread molded by the mold 22, and has a molding surface 46A (the surface of the master mold 46 for molding the rubber mold 50) that corresponds to the tread surface T1. The master mold 46 can be produced by cutting the tread design out of, for example, engineering wood or plaster.

[0027] In step 2, as shown in Fig. 2(B), a mounting hole molding material 48 is attached to the master mold 46. The mounting hole molding material 48 is a member that molds mounting holes 54 (Fig. 2(E)) for attaching the void molding material 42 to the rubber mold 50.

[0028] Fig. 3 is a perspective view showing the master mold 46 with the mounting hole molding material 48 attached. In Fig. 3, the concaves and convexes of the molding surface 46A and the mounting hole molding material 48 on the underside are shown with solid lines so that the molding surface 46A and the mounting hole molding material 48 on the underside can be seen through, and the mounting surface of the mounting hole molding material 48 relative to the master mold 46 is shown with dashed lines (the same applies to Fig. 4).

[0029] In this example, the mounting hole molding material 48 is attached to the molding surface 46A of the master mold 46 using an adhesive or the like. The mounting hole molding material 48 may be attached by forming a groove in the molding surface 46A and embedding a portion of the mounting hole molding material 48 in the groove. The portion of the mounting hole molding material 48 that protrudes from the molding surface 46A has a shape that corresponds to the embedded portion 42B of the void molding material 42.

[0030] In step 3, as shown in FIG. 2(C), a rubber material such as silicone rubber is poured into the master mold 46 with the mounting hole molding member 48 attached, and the molding surface 46A is covered and filled with the rubber material, thereby producing a rubber mold 50. In detail, as shown in FIG. 4, the master mold 46 is placed in a mold 56 for molding the rubber mold 50 and the mold is closed, and the rubber material is poured into the space 58 between the mold 56 and the master mold 46 and hardened. Thereafter, the rubber mold 50 is obtained by demolding as shown in FIG. 2(D). A plurality of mounting holes 54 are formed in the molding surface 50A of the obtained rubber mold 50 (the surface of the rubber mold 50 for molding the plaster mold 52) as shown in FIG.

[0031] In step 4, as shown in Fig. 2(E), the void molding material 42 is inserted into the mounting hole 54 of the rubber mold 50 and attached. As a result, as shown in Fig. 6, the void molding material 42 is fixed to the rubber mold 50 with a part of it (embedded part 42B) embedded in the rubber mold 50 and the remaining part (molded part 42A) protruding from the molding surface 50A.

[0032] In step 5, as shown in Fig. 2(F), plaster is poured into the rubber mold 50 to which the void molding material 42 is attached, to produce a plaster mold 52 with the void molding material 42 fixed in place. In detail, as shown in Fig. 6, the rubber mold 50 is placed in a mold 60 for molding the plaster mold 52 and closed, and plaster is poured into the molding surface 50A of the rubber mold 50 and allowed to harden. At this time, the void molding material 42 is fixed in a state where a portion of it is embedded in the plaster mold 52. The plaster mold 52 is then demolded to obtain the plaster mold 52.

[0033] Fig. 7 is a perspective view showing a plaster mold 52. A void molding material 42 is fixed to a molding surface 52A (the surface of the plaster mold 52 for molding the metal mold 22) of the plaster mold 52. In Fig. 7, the unevenness of the molding surface 52A and the void molding material 42 are shown by solid lines so that the molding surface 52A and the void molding material 42 on the lower surface side can be seen through, and the portion of the void molding material 42 that is embedded in the plaster mold 52 is shown by dashed lines (the same applies to Fig. 8).

[0034] In step 6, as shown in Figures 2(G) and 2(H), molten metal is poured into the plaster mold 52 to which the void molding material 42 is fixed, thereby casting the mold body 40 with the void molding material 42 cast inside. In detail, as shown in Figure 8, the plaster mold 52 is placed in a mold 62 for molding the metal mold 22 and the mold is closed, and molten metal is poured into the space 64 between the mold 62 and the plaster mold 52. After solidification by cooling, the mold is opened as shown in Figure 9, and the plaster mold 52 is destroyed. In this way, the metal mold 22 is molded as shown in Figure 2(I), and then machining, finish polishing, etc. are added to form the final shape.

[0035] In the manufacturing method described above, in the first embodiment, as shown in Figures 6 and 10(C) to (D), the void molding material 42 is attached to the rubber mold 50 together with the support member 66 in a state in which the void molding material 42 is supported using the support member 66, and in this state, plaster is poured into the rubber mold 50 to produce a plaster mold 52 in which the void molding material 42 is fixed.

[0036] The support member 66 is embedded in the rubber mold 50 together with the void molding material 42, and is a member that supports the posture of the void molding material 42 protruding from the molding surface 50A of the rubber mold 50. By supporting the void molding material 42 in this way, the posture of the void molding material 42 can be stabilized when plaster is poured into the rubber mold 50. Therefore, the positioning accuracy of the void molding material 42 in the plaster mold 52 can be improved, and the positioning accuracy of the void molding material 42 cast-in to the mold body 40 can be improved.

[0037] In this example, the support members 66 are provided in contact with both side surfaces of the plate-shaped void molding material 42 so as to support the void molding material 42 from both sides. More specifically, as shown in FIGS. 6 and 10(C), the support members 66 are connected across both widthwise sides of the embedded portion 42C of the void molding material 42 in the rubber mold 50, spanning the deepest portion. That is, the support member 66 has a shape in which a pair of rod-shaped support bars 66A, 66A extend in the depth direction along both side surfaces of the void molding material 42 in the embedded portion 42C of the void molding material 42, and are connected by a connecting portion 66B spanning the deepest portion of the embedded portion 42C. Therefore, the support member 66 has a so-called U-shape or C-shape. Having such a shape in which both sides are connected can further improve the positioning accuracy of the void molding material 42.

[0038] In this embodiment, the support members 66 are made of the same material as the mold body 40, that is, soft metal such as aluminum or an aluminum alloy. This makes it easier to finish the surface of the tread molding surface 40A when the support members 66 are exposed to the tread molding surface 40A of the mold 22, and also minimizes the impact on the tire appearance quality due to transfer to the tire T.

[0039] One support member 66 may be provided for each void molding material 42, but preferably, each void molding material 42 is supported by multiple support members 66. This can further improve the positioning accuracy of the void molding material 42. In the example shown in Fig. 6, each void molding material 42 is supported by two support members 66, 66, and a support member 66 is provided at each end of the void molding material 42 in the longitudinal direction.

[0040] Here, when the dimension of the void molding material 42 in the longitudinal direction is the total length L (see FIG. 11), the both ends of the void molding material 42 refer to a range (L1) within 30% of the total length L from each of the both ends in the longitudinal direction of the void molding material 42. The support members 66 are preferably installed at positions 10 to 30% of the total length L from each of the both ends of the void molding material 42. More preferably, in addition to the both ends, the support members 66 are also provided in the central portion in the longitudinal direction, so that the void molding material 42 is supported at three points in the longitudinal direction.

[0041] As described above, in this embodiment, since the support members 66 are used to support the void molding material 42, it is preferable to attach the mounting hole molding material 48 to the master mold 46 in the above step 2 as follows: As shown in Fig. 3, a protrusion 68 corresponding to the shape of the support member 66 is provided on the mounting hole molding material 48. The protrusion 68 is used to mold an insertion recess 70 (see Fig. 5) into which the support member 66 is to be inserted into the rubber mold 50.

[0042] By providing the protrusions 68 on the mounting hole molding material 48, the rubber material is filled along the shape of the protrusions 68 as shown in Fig. 10(A). Therefore, as shown in Fig. 10(B) and Fig. 5, the mounting holes 54 formed on the molding surface 50A of the rubber mold 50 have a shape corresponding to the embedded portion 42B of the void molding material 42, and also have insertion recesses 70 for the support members 66.

[0043] Next, in step 4, as shown in Figures 10(C) and 6, the void molding material 42 is inserted into the mounting hole 54 together with the support member 66 and mounted. At this time, since the insertion recess 70 is formed as described above, they can be mounted without any gaps.

[0044] In the first embodiment, the support member 66 is attached to the rubber die 50 in a state where it protrudes from the molding surface 50A of the rubber die 50. That is, a portion 66C of the support member 66 protrudes from the molding surface 50A, and this protruding portion 66C also supports the void molding material 42. Therefore, the positioning accuracy of the void molding material 42 can be further improved.

[0045] The portion 66C exposed to the outside from the rubber mold 50 is embedded in the plaster mold 52 as shown in Figures 10(D) and 10(E) when the plaster mold 52 is produced in step 5. Therefore, as shown in Figure 11, the plaster mold 52 is produced in a state in which the portion 66C of the support member 66 is embedded together with the molded portion 42A of the void molding material 42.

[0046] Next, in step 6, when molten metal is poured into the plaster mold 52, the portion of the plaster mold 52 exposed from the molding surface 52A is embedded in the mold body 40, as shown in Figure 10(F). Therefore, as shown in Figures 10(G) and 9, the portion 66C of the support member 66 embedded in the plaster mold 52 protrudes from the tread molding surface 40A together with the molding portion 42A of the void molding material 42. Therefore, as shown in Figure 10(H), after the mold body 40 is cast, this protruding portion 66C of the support member 66 is removed.

[0047] 10(G), it is preferable that a breaking portion 72 for removing the portion 66C is provided in the support member 66. The breaking portion 72 may have various configurations that facilitate cutting off the portion 66C from the support member 66, and in this example, is configured by a notch.

[0048] 12(A) to 12(H) are cross-sectional views of the main part for explaining the manufacturing process of the mold 22 according to the second embodiment, and FIG. 13 is a perspective view of the main part of the plaster mold 52 according to the second embodiment.

[0049] In the second embodiment, as shown in FIG. 12(C), the support member 66X is attached to the rubber mold 50 in a state where it does not protrude from the molding surface 50A of the rubber mold 50, which differs from the support member 66 of the first embodiment, which is attached to the rubber mold 50 in a state where it protrudes from the molding surface 50A of the rubber mold 50.

[0050] In detail, the support member 66X, like the first embodiment, has a shape that is connected across both sides in the width direction across the deepest part of the embedded portion 42C of the void molding material 42 in the rubber mold 50, and has a pair of support bars 66A, 66A and a connecting portion 66B. However, the length of the support bars 66A, 66A on both sides differs from the support member 66 of the first embodiment. In the support member 66X, the support bar 66A is formed short so as not to protrude from the molding surface 50A of the rubber mold 50. Therefore, a cavity 74 is provided between a tip 66X1 (the tip of the support bar 66A) of the support member 66X and the molding surface 50A. The cavity 74 is provided as an open end of the insertion recess 70, and in this example, is formed wider than the portion where the support member 66X is fitted.

[0051] 12(A) and 12(B), as in the first embodiment, a mounting hole molding material 48 provided with protrusions 68 corresponding to the shape of the support member 66X is attached to a master mold 46 to prepare a rubber mold 50. The void molding material 42 is inserted and attached together with the support member 66X into a mounting hole 54 having an insertion recess 70 formed thereby. At this time, in the second embodiment, a cavity 74 is formed between the tip 66X1 of the support member 66X and the molding surface 50A, as shown in FIG.

[0052] Next, when the plaster mold 52 is produced in step 5, in the second embodiment, as shown in Fig. 12(D), the support member 66X does not have a portion that is embedded in the plaster mold 52, and the tip 66X1 of the support member 66X is located at a position separated from the molding surface 52A of the plaster mold 52. In detail, as shown in Figs. 12(E) and 13, a plaster protrusion 76 that protrudes from the molding surface 52A is formed by a cavity 74 on the molding surface 52A of the plaster mold 52, and the tip 66X1 of the support member 66X is located on the upper surface of the plaster protrusion 76. Therefore, in this example, after the plaster mold 52 is demolded and removed, the plaster protrusion 76 is scraped off and removed, as shown in Fig. 12(F).

[0053] Thereafter, in step 6, when molten metal is poured into the plaster mold 52, the support members 66X are entirely embedded in the mold body 40, and no support members 66X are exposed to the tread molding surface 40A, as shown in Figures 12(G) and 12(H). In other words, the void molding material 42 protrudes from the tread molding surface 40A, but the support members 66X installed to support it are entirely embedded in the mold body 40 and are not exposed to the tread molding surface 40A. This makes it possible to prevent deterioration in the appearance quality of the tire.

[0054] In the second embodiment, the support member 66X preferably supports the void molding material 42 in a range of 70 to 95% in the depth direction from the deepest part in the embedded portion 42C of the void molding material 42 in the rubber mold 50. That is, in the embedded portion 42C of the void molding material 42, where the depth from the deepest part to the molding surface 50A is D0, the range D1 supported by the support member 66X (the range from the deepest part to the tip 66X1) preferably is 70 to 95% of D0. By supporting 70 to 95% of the region from the deepest part with the support member 66X in this way, the function of supporting the void molding material 42 is ensured, while the effect of not exposing the support member 66X to the tread molding surface 40A can be more reliably achieved.

[0055] With regard to the second embodiment, the other configurations including the support member 66X are basically the same as the support member 66 and other configurations of the first embodiment except for the above points, and therefore description thereof will be omitted.

[0056] 14 is a perspective view of a main portion of a gypsum mold 52 according to a third embodiment. The third embodiment differs from the support member 66 of the first embodiment in that the support member 66Y is not connected across both sides of the void molding material 42 in the width direction. That is, in the third embodiment, the support member 66Y is composed of a pair of rod-shaped support bars 66A, 66A that support the void molding material 42 from both sides, and both bars are provided separately. Note that while only the support member 66Y on the front side is shown in FIG. 14, a similar support member 66Y is also provided on the opposite side.

[0057] This embodiment is the same as the first embodiment in that the support member 66Y is attached to the rubber mold 50 in a state where it protrudes from the molding surface 50A of the rubber mold 50, and therefore the plaster mold 52 is made in a state where a portion 66C of this protruding support member 66Y is embedded, and that the portion 66C of the support member 66Y protruding from the tread molding surface 40A of the mold body 40 is removed after the mold body 40 is cast.

[0058] With regard to the third embodiment, the other configurations including the support member 66Y are basically the same as the support member 66 and other configurations of the first embodiment except for the above points, and therefore description thereof will be omitted.

[0059] The above embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. [Explanation of symbols]

[0060] 22... Tire manufacturing mold, 40... Mold body, 40A... Tread molding surface, 42... Void molding material, 42A... Embedded portion, 50... Rubber mold, 50A... Molding surface, 52... Plaster mold, 52A... Molding surface, 66, 66X, 66Y... Support member, 72... Breaking portion

Claims

1. A method for manufacturing a tire manufacturing mold, comprising: a mold body for molding a tread surface; and a void molding material made of a different material from the mold body for molding voids in the tread surface, Attaching the void molding material together with the support member to a rubber mold in a state in which the void molding material is supported by the support member; Pour plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and Casting the mold body with the void molding material cast in it by pouring metal into the gypsum mold; Including, the support member is a member that is embedded in the rubber mold together with the void molding material and supports the posture of the void molding material protruding from the molding surface of the rubber mold. A method for manufacturing molds for tire manufacturing.

2. 2. The method for manufacturing a tire manufacturing mold according to claim 1, wherein the support member is attached to the rubber mold in a state where it protrudes from the molding surface of the rubber mold, thereby producing the plaster mold in a state where the protruding portion is embedded, and after casting the mold body, the part of the support member protruding from the tread molding surface of the mold body is removed.

3. A method for manufacturing a tire manufacturing mold comprising: a mold body for molding a tread surface; and a void molding material made of a material different from the mold body for molding voids in the tread surface, Attaching the void molding material together with the support member to a rubber mold in a state in which the void molding material is supported by the support member; Pour plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and Casting the mold body with the void molding material cast in it by pouring metal into the gypsum mold; Including, the support member is attached to the rubber mold in a state where it protrudes from the molding surface of the rubber mold, and the plaster mold is prepared in a state where the protruding portion is embedded; and after casting the mold body, the part of the support member protruding from the tread molding surface of the mold body is removed, a method for manufacturing a tire manufacturing mold, wherein the support member has a breaking portion for removing the portion, and after the mold body is cast, the support member is broken using the breaking portion to remove the portion.

4. A method for manufacturing a tire manufacturing mold comprising: a mold body for molding a tread surface; and a void molding material made of a material different from the mold body for molding voids in the tread surface, Attaching the void molding material together with the support member to a rubber mold in a state in which the void molding material is supported by the support member; Pour plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and Casting the mold body with the void molding material cast in it by pouring metal into the gypsum mold; Including, The method for manufacturing a mold for manufacturing a tire includes attaching the support member to the rubber mold in a state where the support member does not protrude from the molding surface of the rubber mold.

5. 5. The method for manufacturing a tire manufacturing mold according to claim 4, wherein the support member supports the void molding material in a range of 70 to 95% in a depth direction from a deepest part of the void molding material embedded in the rubber mold.

6. A method for manufacturing a tire manufacturing mold comprising: a mold body for molding a tread surface; and a void molding material made of a material different from the mold body for molding voids in the tread surface, Attaching the void molding material together with the support member to a rubber mold in a state in which the void molding material is supported by the support member; Pour plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and Casting the mold body with the void molding material cast in it by pouring metal into the gypsum mold; Including, A method for manufacturing a tire manufacturing mold, wherein a plurality of the void molding materials are provided in the mold body, and each void molding material is supported by a plurality of the support members.

7. A method for manufacturing a tire manufacturing mold, comprising: a mold body for molding a tread surface; and a void molding material made of a material different from the mold body for molding voids in the tread surface, Attaching the void molding material together with the support member to a rubber mold in a state in which the void molding material is supported by the support member; Pour plaster into the rubber mold while the void molding material is supported to prepare a plaster mold in which the void molding material is fixed; and Casting the mold body with the void molding material cast in it by pouring metal into the gypsum mold; Including, A method for manufacturing a tire manufacturing mold, wherein the support member is connected across the deepest part of the void molding material embedded in the rubber mold and on both sides in the width direction.

8. The method for manufacturing a tire manufacturing mold according to any one of claims 1 to 7, wherein the support member is made of the same material as the mold body.

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