CN111465478A

CN111465478A - Method for manufacturing tire mold

Info

Publication number: CN111465478A
Application number: CN201880076776.8A
Authority: CN
Inventors: 石原泰之
Original assignee: Hashiishi Corp
Current assignee: Hashiishi Corp; Bridgestone Corp
Priority date: 2017-11-27
Filing date: 2018-07-25
Publication date: 2020-07-28
Also published as: JP2019093672A; WO2019102649A1

Abstract

The split mold of the tire mold can be easily manufactured, and the manufacturing efficiency of the tire mold can be improved. A method for manufacturing a tire mold having a plurality of divided molds annularly arranged along a tire circumferential direction. The method for manufacturing the tire mold comprises the following steps: forming a plurality of protruding parts (16) connected by a connecting part (17); manufacturing a main die body mould (20); assembling the plurality of protrusions (16) to a mold main body mold (20); and removing the connecting part (17) from the plurality of protrusions (16) to produce a divided mold having a mold main body mold (20) and the plurality of protrusions (16).

Description

Method for manufacturing tire mold

Technical Field

The present invention relates to a method for manufacturing a tire mold having a plurality of divided molds annularly arranged along a tire circumferential direction.

Background

In the split mold of the tire mold, the shape of the molding portion for molding the tire is complicated, and the molding portion is formed in a shape that is difficult to form by machining in accordance with the shape of the tread portion of the tire. Therefore, the production of the split mold is widely performed by a casting production method. Further, a method of manufacturing a mold for tire molding in which a 1-piece assembled mold (split mold) is manufactured from 1 annular casting is known (see patent document 1).

By making a 1-component split mold of a mold for a tire from 1 casting, the manufacturing efficiency becomes high. The casting conditions are the same for all the divided molds, and the casting results (shrinkage, etc.) are also the same. However, as the tire molded by the tire mold becomes larger, the weight of the cast product increases, and the casting becomes difficult. In addition, since the casting time and the solidification time become long, high technical force is required to cope with the casting defect. Depending on the weight of the cast product, the weight of the melt may exceed the weight that can be poured.

Therefore, in general, when a mold for manufacturing a tire smaller than a tire for truck/bus (or a tire of the same degree) is manufactured, a 1-component divided mold is manufactured from 1 casting. In the case of manufacturing a mold for a tire having a size not smaller than that of a truck or bus tire, castings (blanks) of divided molds are cast independently of each other, and 1 divided mold is manufactured from 1 blank. In particular, in the case of a mold for a large tire, it is difficult to directly form a molding portion of a divided mold (blank) by precision casting from the aspect of dimensional accuracy, and the molding portion of the blank is machined by machining.

Fig. 20 to 25 are views showing steps of manufacturing the conventional tire mold 100, and schematically show the blank 120 or the split mold 110 of the split mold 110 at each stage. In fig. 20 to 24, the shape and the like of the split die 110 are shown by a chain line on the blank 120. Fig. 20 to 23 show the processing steps of 1 divided die 110 (blank 120), and fig. 24 and 25 show the processing steps of a plurality of divided dies 110. Fig. 20B to 23B show the blank 120 as viewed in the direction of arrow V1 from a to a in fig. 20 to 23, respectively. Fig. 24 a and 25 a are plan views of the plurality of billets 120 or the plurality of split molds 110, and fig. 24B and 25B are cross-sectional views taken along the line V2-V2 in fig. 24 a and 25 a, respectively.

As shown in the drawing, a block-shaped blank 120 (see fig. 20) is formed by casting. At the same time, the solidified riser portion (riser portion 121) is formed integrally with the blank 120. Next, the feeder head 121 is cut from the blank 120 (see fig. 21). One end portion (the 1 st end portion 122) of the blank 120 is machined by machining, and the reference surface 111 of the split die 110 is formed on the blank 120 (see fig. 22). Further, 2 side portions 123 of the blank 120 are processed to form 2 divided surfaces 112 of the divided die 110 on the blank 120 (see fig. 23).

Next (see fig. 24), the plurality of blanks 120 are combined into a ring shape with the dividing surfaces 112 in contact with each other. In this state, the other end portions (2 nd end portions 124) of the plurality of blanks 120 are machined by machining (see fig. 25), and the end surfaces 113 of the split molds 110 are formed on the blanks 120. Further, the inner peripheral portion 125 and the outer peripheral portion 126 of the plurality of blanks 120 are processed to form the forming portion 114 and the back surface portion 115 of the split mold 110 in the blank 120. In addition, the forming portion 114 is provided with a protrusion 116 for forming a recess in the tread portion of the tire.

When the 1-component split mold 110 of the tire mold 100 cannot be manufactured from 1 annular casting, the blanks 120 of the split molds 110 are cast independently of each other, and 1 split mold 110 is manufactured from 1 blank 120 by machining, but the machining of the blank 120 of the split mold 110 requires labor and time. In particular, since the forming portion 114 is provided with the protrusion 116, the shape becomes complicated, and the processing thereof requires much labor and time. Therefore, it is difficult to improve the manufacturing efficiency of the split mold 110, and the period of time for manufacturing the tire mold 100 becomes long. In contrast, when the blank 120 is formed into a shape close to the finished shape of the split mold 110, the machining of the blank 120 is simplified. However, in this case, it takes time and labor to process the wooden mold for casting the material 120. From the above, it is desired to improve the manufacturing efficiency of the tire mold 100 and to manufacture the tire mold 100 in a shorter period of time.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2004-358849

Disclosure of Invention

Problems to be solved by the invention

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to enable a split mold for a tire mold to be easily manufactured and to improve the manufacturing efficiency of the tire mold.

Means for solving the problems

The present invention relates to a method for manufacturing a tire mold having a plurality of divided molds annularly arranged along a tire circumferential direction. The method for manufacturing the tire mold comprises the following steps: forming a plurality of protruding parts connected by a connecting part; manufacturing a main body mould of the mould; assembling a plurality of protrusions to a mold main body mold; and manufacturing a divided mold having a mold main body mold and a plurality of protrusions by removing the connecting portions from the plurality of protrusions.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, the split mold of the tire mold can be easily manufactured, and the manufacturing efficiency of the tire mold can be improved.

Drawings

Fig. 1 is a view showing a tire mold according to embodiment 1.

Fig. 2 is a perspective view showing a manufacturing process of a tire mold according to embodiment 1.

Fig. 3 is a perspective view showing a manufacturing process of a tire mold according to embodiment 1.

Fig. 4 is a perspective view showing a manufacturing process of a tire mold according to embodiment 1.

Fig. 5 is a perspective view showing a manufacturing process of a tire mold according to embodiment 1.

Fig. 6 is a perspective view showing a manufacturing process of a tire mold according to embodiment 1.

Fig. 7 is a perspective view of the completed tire mold.

Fig. 8 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 9 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 10 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 11 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 12 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 13 is a perspective view showing a manufacturing process of a tire mold according to embodiment 2.

Fig. 14 is a perspective view showing a manufacturing process of a tire mold according to embodiment 3.

Fig. 15 is a perspective view showing a manufacturing process of a tire mold according to embodiment 3.

Fig. 16 is a perspective view showing a manufacturing process of a tire mold according to embodiment 3.

Fig. 17 is a view showing a hole and a groove of a protrusion.

Fig. 18 is a perspective view showing a manufacturing process of a tire mold according to embodiment 3.

Fig. 19 is a perspective view showing a manufacturing process of a tire mold according to embodiment 3.

Fig. 20 is a diagram showing a manufacturing process of a conventional tire mold.

Fig. 21 is a diagram showing a manufacturing process of a conventional tire mold.

Fig. 22 is a diagram showing a manufacturing process of a conventional tire mold.

Fig. 23 is a diagram showing a manufacturing process of a conventional tire mold.

Fig. 24 is a diagram showing a manufacturing process of a conventional tire mold.

Fig. 25 is a diagram showing a manufacturing process of a conventional tire mold.

Detailed Description

An embodiment of a method for manufacturing a tire mold according to the present invention will be described with reference to the drawings.

In the method of manufacturing a tire mold according to the present embodiment, a tire mold and a split mold of the tire mold are manufactured. The tire mold is a tire molding mold and is used for molding (vulcanizing) a tire. The tire is molded by a tire mold and vulcanized.

(embodiment 1)

Fig. 1 is a view showing a tire mold 1 according to embodiment 1. Fig. 1 a is a plan view of the tire mold 1 viewed from the outer side in the tire width direction, and fig. 1B is a sectional view of the tire mold 1 taken along line X1-X1 of fig. 1 a.

As shown in the drawing, the tire mold 1 is an annular outer mold for molding the outer surface of the tire, and is provided in a tire molding device (vulcanizing device). The tire mold 1 surrounds a ring-shaped tire and forms a tread portion of the tire.

With respect to the direction of the tire mold 1, the width direction of the tire mold 1 (mold width direction W1) coincides with the width direction of the tire (tire width direction). The radial direction of the tire mold 1 (mold radial direction K1) coincides with the radial direction of the tire (tire radial direction), and the circumferential direction of the tire mold 1 (mold circumferential direction S1) coincides with the circumferential direction of the tire (tire circumferential direction).

The tire mold 1 includes a plurality of (here, 18) split molds 10 arranged annularly along a mold circumferential direction S1 (tire circumferential direction), and a tire is molded by the plurality of split molds 10. The plurality of split molds 10 are mold pieces (segments) split in the mold circumferential direction S1, and are tread molds for shaping the tread portion of the tire. The plurality of split molds 10 move in the mold radial direction K1 (tire radial direction) in the tire molding apparatus. The tire mold 1 includes a reference surface 11 serving as a reference surface for processing, an end surface 12 located on the opposite side of the reference surface 11, a molding portion 13 formed on the tire side, a back surface portion 14 formed on the back surface side, and 2 divided surfaces 15 in each divided mold 10.

The reference surface 11 is one end surface of the split mold 10 in the mold width direction W1 (tire width direction). The end face 12 is the other end face in the die width direction W1 of the split die 10. The molding portion 13 is an inner peripheral portion of the tire mold 1 and is located inside in the mold radial direction K1. The back surface portion 14 is an outer peripheral portion of the tire mold 1, and is an inclined surface located on the opposite side (outside in the mold radial direction K1) of the molding portion 13. The split surfaces 15 are side surfaces of the split mold 10 located on both sides in the mold circumferential direction S1.

When the tire is molded, the plurality of split molds 10 of the tire mold 1 are sequentially arranged along the mold circumferential direction S1 in a state where the split surfaces 15 are in contact with each other. Thereby, the plurality of split molds 10 are combined in a ring shape to surround the tire. In this state, the tire mold 1 and the molding portion 13 are arranged along the mold width direction W1. The tire mold 1 is in contact with a tire (tread portion) at a forming portion 13 of the split mold 10, and the tire is formed by the forming portion 13. The forming portion 13 is provided with a protrusion 16. The forming portion 13 forms a concave portion (for example, a groove or a sipe) in the tread portion of the tire by the protrusion portion 16.

Next, a method of manufacturing the tire mold 1 according to embodiment 1 will be described.

Fig. 2 to 6 are perspective views showing a manufacturing process of the tire mold 1 according to embodiment 1. Fig. 2 to 6 show 1 divided mold 10 of the tire mold 1. Fig. 7 is a perspective view of the completed tire mold 1, and is also a perspective view of the completed tire mold 1 according to embodiment 2 described later.

When the tire mold 1 is manufactured, the plurality of protrusions 16 connected by the connection portion 17 are formed. Further, a mold body 20 is produced, and the plurality of protrusions 16 are assembled to the mold body 20. The coupling portion 17 is removed from the plurality of protrusions 16, and a divided mold 10 having a mold body 20 and the plurality of protrusions 16 is manufactured. The respective steps of the method for manufacturing the tire mold 1 will be described in detail below.

In the step of forming the plurality of protrusions 16 connected by the connection portion 17, a plate-like protrusion blank 30 is prepared. The 1 projection material 30 corresponds to the 1 divided die 10, and is, for example, a forged product made of a steel material. The number of prepared protruding members 30 is 18 corresponding to 1 set of the tire mold 1, but the invention is not limited thereto. As shown in fig. 2, the outer surface (inner peripheral surface, outer peripheral surface, upper surface, lower surface, etc.) of the prepared projection blank 30 is subjected to machining (turning, milling, etc.) to adjust the surface shape of the projection blank 30.

Next, as shown in fig. 3, the protruding blank 30 with the adjusted surface shape is subjected to shape blanking, and unnecessary portions are blanked out of the protruding blank 30. The shape punching process is a mechanical process such as milling, wire electric discharge machining, fusing (gas fusing, arc fusing), plasma cutting, and abrasive water jet (high-pressure water cutting). By the shape punching process, a plurality of protruding portions 16, coupling portions 17, one end joining portion (here, upper end joining portion 18), and the other end joining portion (here, lower end joining portion 19) are left, and unnecessary portions are cut out from the protruding blank 30. Thereby, the coupling portion 17 and the plurality of protrusions 16 are formed in the protrusion blank 30.

The connecting portion 17 is a member that connects the mutually separated protrusions 16, and also serves as a reinforcing portion that reinforces a connected body having the connecting portion 17 and the plurality of protrusions 16. All the protrusions 16 of the 1 split mold 10 are connected by the connection portion 17. The upper end joint 18 and the lower end joint 19 are members for holding the plurality of protrusions 16 and the coupling portion 17, and are connected to upper end portions and lower end portions of the plurality of protrusions 16 and the coupling portion 17. The plurality of projections 16 and the coupling portions 17 have machining margins, and the plurality of projections 16 and the coupling portions 17 are formed to be larger than the respective final shapes.

In the shape blanking process of the protruding blank 30, fusing (particularly, gas fusing), plasma cutting, or abrasive water jet is preferably used. That is, in the case of fusing, plasma cutting, and abrasive water jet, the cutting speed of unnecessary portions is extremely high. Therefore, the number of processing steps for the shape punching process can be reduced to 50% or less compared to other processes.

After the unnecessary portions of the protrusion blank 30 are cut (shape punched), as shown in fig. 4, the plurality of protrusions 16 and the coupling portions 17 are subjected to machining such as NC milling, and the shapes of the plurality of protrusions 16 and the coupling portions 17 are adjusted. At this time, the coupling portion 17 is processed into a shape recessed from the protrusion 16. As a result, when the plurality of protrusions 16 are assembled to the mold body 20, a gap is formed between the coupling portion 17 and the mold body 20. The upper end joint 18 and the lower end joint 19 are grasping portions to be grasped by the processing machine at the time of machining.

As described above, the plurality of protrusions 16 connected by the connection portion 17 are formed by subjecting the plate-like protrusion blank 30 to various machining processes. At this time, the upper end joining portion 18 and the lower end joining portion 19 are connected to the upper end portions and the lower end portions of the plurality of protrusions 16 and the coupling portion 17.

Next, in the step of manufacturing the die body mold 20, as shown in fig. 5, a block-shaped die body mold blank 31 is prepared. The 1 die main body die blank 31 corresponds to the 1 divided die 10, and is formed by, for example, forging or casting. The number of the prepared mold body molds 31 is 18 corresponding to 1 set of the tire molds 1, but the number is not limited thereto. Various machining processes are performed on the prepared die body mold blank 31. Thus, the reference surface 11, the end surface 12, the molded portion 13, the back surface portion 14, and the 2 dividing surfaces 15 are formed in the die body blank 31 (the die body die 20).

As described above, the die body mold 20 is produced by subjecting the block-shaped die body mold blank 31 to various machining processes.

Next, in the step of assembling the plurality of protrusions 16 to the mold body 20, the plurality of formed protrusions 16 are assembled to the manufactured mold body 20. That is, as shown in fig. 5, the mold body 20 is fixed, and the plurality of protrusions 16 are assembled to the molding portion 13 of the mold body 20 while grasping the upper end joining portion 18 and the lower end joining portion 19. When the plurality of protrusions 16 are assembled to the mold body 20, the plurality of protrusions 16 and the molded part 13 of the mold body 20 are joined by, for example, welding the periphery of the protrusions 16. In contrast, when the plurality of protrusions 16 are assembled to the mold body 20, for example, a fixing member such as a screw may be used, or welding and a screw may be used in combination.

Next, the coupling portion 17 is removed from the plurality of protrusions 16, and the divided mold 10 having the mold body 20 and the plurality of protrusions 16 is manufactured. At this time, as shown in fig. 6, all the coupling portions 17 and 2

joint portions

18 and 19 are removed by machining such as milling. When the coupling portion 17 is removed, a gap is formed between the coupling portion 17 and the molding portion 13 of the mold body 20. Therefore, the connecting portion 17 can be easily removed without damaging the forming portion 13 of the mold body 20. After the connecting portion 17 is removed, the plurality of protrusions 16 are subjected to machining such as milling, and the plurality of protrusions 16 are finished.

As described above, the coupling portion 17 and the like are removed from the plurality of protrusions 16, whereby 1 divided mold 10 having the mold body 20 and the plurality of protrusions 16 is produced.

Through the above steps, 1 set (18) of the divided molds 10 of the tire mold 1 is prepared, and the 18 divided molds 10 are arranged in a ring shape and combined. Thus, 1 tire mold 1 shown in fig. 7 was manufactured.

As described above, separately from the production of the die main body mold 20, the protrusion blank 30 is machined to form the plurality of protrusions 16 connected by the connecting portions 17. Therefore, the plurality of protrusions 16 can be easily produced, and the mold body 20 can also be easily produced. Even if the plurality of protrusions 16 and the mold body mold 20 have shapes that are difficult to form, they can be easily processed. Therefore, the efficiency of manufacturing the split mold 10 and the tire mold 1 can be improved, and the tire mold 1 can be manufactured in a short period of time.

The divided molds 10 are produced by combining the plurality of protrusions 16 produced in the different steps with the mold body mold 20. Along with this, it is easy to standardize the plurality of protrusions 16 and the mold main body mold 20. By standardizing the plurality of protrusions 16 and the mold body mold 20, the work can be made more efficient, and the manufacturing period of the tire mold 1 can be shortened. The accuracy of processing the plurality of protrusions 16 and the die main body mold 20 can be improved.

Next, other embodiments will be described. In the following embodiment, the same matters as those in embodiment 1 are omitted, and matters different from embodiment 1 are described.

(embodiment 2)

A method for manufacturing the tire mold 1 according to embodiment 2 will be described.

Fig. 8 to 13 are perspective views showing a manufacturing process of the tire mold 1 according to embodiment 2.

In the step of forming the plurality of protrusions 16 connected by the connection portion 17, the protrusion blank 30 is prepared. The protruding blank 30 is annular (circular ring-shaped) and is formed, for example, by casting. A plurality of protrusions 16 provided in the plurality of divided molds 10 are formed from the 1 annular protrusion blank 30. Here, the plurality of protrusions 16 of the 9 divided molds 10 are formed in 1 protrusion blank 30. The tire mold 1 includes 18 split molds 10. Thus, 2 annular projecting blanks 30 are prepared for manufacturing 1 tire mold 1. However, the number of the plurality of protrusions 16 formed by 1 annular protrusion blank 30 and the number of the prepared protrusion blanks 30 are not limited to these. As shown in fig. 8, the outer surface (inner peripheral surface, outer peripheral surface, upper surface, lower surface, etc.) of the prepared annular projection blank 30 is subjected to machining (turning, milling, etc.) to adjust the surface shape of the projection blank 30.

Next, as shown in fig. 9, the annular protrusion blank 30 whose surface shape is adjusted is subjected to shape blanking, and unnecessary portions are blanked from the protrusion blank 30. By the shape punching process, a plurality of projecting portions 16, coupling portions 17, upper end joining portions 18, lower end joining portions 19, and annular joining portions 21 are left, and unnecessary portions are cut out from the projecting blank 30. The annular joint 21 is a portion connecting the plurality of projections 16 of each divided mold 10 and the coupling portion 17, and here, the plurality of projections 16 of the 9 divided molds 10 and the coupling portion 17 are connected.

After the unnecessary portions of the annular projection blank 30 are cut (shape-punched), as shown in fig. 10, the plurality of projections 16 and the coupling portions 17 are subjected to machining such as NC milling, and the shapes of the plurality of projections 16 and the coupling portions 17 are adjusted. At this time, the coupling portion 17 is formed in a shape recessed from the protrusion 16.

Next, as shown in fig. 11, the annular projection blank 30 from which the unnecessary portion has been cut out is subjected to mechanical processing such as milling, wire electrical discharge machining, fusing, plasma cutting, abrasive water jet, and the like. Thereby, the annular joint portion 21 is cut out from the protrusion blank 30.

As described above, the plurality of protrusions 16 and the coupling portions 17 of the 9 divided molds 10 are formed at a time by subjecting 1 annular protrusion blank 30 to various machining processes. At this time, the upper end joining portion 18 and the lower end joining portion 19 are connected to the upper end portions and the lower end portions of the plurality of protrusions 16 and the coupling portion 17.

Next, in the step of manufacturing the die main body mold 20, the die main body mold 20 is manufactured by performing various machining processes on the block-shaped die main body mold blank 31, as in embodiment 1.

Next, in the step of assembling the plurality of protrusions 16 to the mold body 20, as in embodiment 1, the plurality of protrusions 16 are assembled to the forming portion 13 of the mold body 20 by joining or the like, as shown in fig. 12.

Next, the coupling portion 17 is removed from the plurality of protrusions 16, and the divided mold 10 having the mold body 20 and the plurality of protrusions 16 is manufactured. At this time, as shown in fig. 13, all the coupling portions 17 and 2

joint portions

18 and 19 are removed by machining such as milling in the same manner as in embodiment 1. Thereafter, the plurality of protrusions 16 are machined to finish the plurality of protrusions 16. Thus, the coupling portion 17 and the like are removed from the plurality of

protrusions

16, and 1 divided mold 10 having the mold body 20 and the plurality of protrusions 16 is produced.

As described above, since the projection material 30 is an annular member, the plurality of projection portions 16 provided in the plurality of divided molds 10 can be formed at a time from 1 annular projection material 30. Therefore, the number of processing steps can be significantly reduced, and the efficiency of forming the plurality of protrusions 16 can be further improved. Further, by forming the plurality of protrusions 16 simultaneously from 1 annular protrusion blank 30, unevenness among the plurality of protrusions 16 can be suppressed.

(embodiment 3)

Next, a method of manufacturing the tire mold 1 according to embodiment 3 will be described.

Here, unlike the embodiments 1 and 2, the projection 16 is assembled to the die body mold 20 by brazing, and the projection 16 and the die body mold 20 are joined by brazing.

Fig. 14 to 16, 18 and 19 are perspective views showing a part of the manufacturing process of the tire mold 1 according to embodiment 3. Fig. 17 is a view showing the hole 33 and the groove 34 of the protrusion 16. A of fig. 17 indicates the hole 33 and the groove 34 as viewed from the direction of the arrow Y1 of fig. 16, and B of fig. 17 indicates the hole 33 and the groove 34 as viewed from the direction of the arrow Y2 of fig. 16.

In the step of forming the plurality of protrusions 16 connected by the connection portion 17, a plate-like protrusion blank 30 is prepared in the same manner as in embodiment 1. As shown in fig. 14, the outer surface (inner peripheral surface, outer peripheral surface, upper surface, lower surface, etc.) of the prepared projection blank 30 is subjected to machining (turning, milling, etc.) to adjust the surface shape of the projection blank 30.

Next, as shown in fig. 15, the protruding blank 30 with the adjusted surface shape is subjected to shape blanking, and unnecessary portions are blanked out of the protruding blank 30. By the shape punching process, a plurality of projecting portions 16, coupling portions 17, upper end joining portions 18, and lower end joining portions 19 are left, and unnecessary portions are cut out from the projecting blank 30.

After the unnecessary portions of the projection material 30 are cut (shape punched), as shown in fig. 16, the plurality of projections 16 and the coupling portions 17 are subjected to machining such as NC milling, and the shapes of the plurality of projections 16 and the coupling portions 17 are adjusted. Further, a plurality of holes 33 are provided in each protrusion 16. Each hole 33 penetrates the protrusion 16. In addition to the hole 33, as shown in fig. 17, a groove 34 is provided on the surface of the protrusion 16 on the side to be engaged with the molding portion 13 of the mold body 20. The plurality of holes 33 are opened at the bottom surface of the groove 34, and the groove 34 is connected to the plurality of holes 33.

As described above, the plurality of protruding portions 16 connected by the connecting portions 17 are formed by subjecting the protruding blank 30 to various machining processes.

Next, in the step of manufacturing the die body mold 20, the die body mold 20 is manufactured by performing various machining processes on the block-shaped die body mold blank 31, as in embodiment 1 or embodiment 2.

Next, in the step of assembling the plurality of protrusions 16 to the mold body 20, as shown in fig. 18, the mold body 20 is disposed below the plurality of protrusions 16 in the lateral direction. Next, the plurality of protrusions 16 facing in the lateral direction are arranged on the mold body 20 and assembled to the forming portion 13 of the mold body 20. The plurality of holes 33 are arranged vertically above the mold body 20. In this state, the protrusion 16 and the die body mold 20 are joined by brazing, and the protrusion 16 is assembled to the die body mold 20. Specifically, the brazing material is put into the plurality of holes 33 provided in the protruding portion 16 in advance, and the mold body 20 and the plurality of protruding portions 16 are put into the heating furnace. In the heating furnace, the mold body 20 and the plurality of protrusions 16 are heated to melt the brazing material in the plurality of holes 33.

The brazing filler metal is melted and spread from the hole 33 toward the groove 34, and spreads over the entire groove 34. The brazing material enters between the protruding portion 16 and the molded portion 13 of the mold main body 20, and joins the protruding portion 16 and the molded portion 13 of the mold main body 20. Thus, the plurality of protrusions 16 are assembled to the molding portion 13 of the mold body 20. Next, a sealing member is driven into the plurality of holes 33 provided in each of the projections 16 to close the holes 33. Thereafter, the surface of the hole 33 is finished.

Next, the coupling portion 17 is removed from the plurality of protrusions 16, and the divided mold 10 having the mold body 20 and the plurality of protrusions 16 is manufactured. At this time, as shown in fig. 19, all the coupling portions 17 and 2

joint portions

18 and 19 are removed by machining such as milling, as in embodiments 1 and 2. Thereafter, the plurality of protrusions 16 are machined to finish the plurality of protrusions 16. Thus, the coupling portion 17 and the like are removed from the plurality of

protrusions

As described above, when the plurality of protrusions 16 are assembled to the die main body die 20, the protrusions 16 and the die main body die 20 are joined by brazing, and the protrusions 16 and the forming portion 13 of the die main body die 20 can be joined without any gap. As a result, the protrusion 16 can be firmly assembled to the mold main body 20. Further, since the joining is performed by brazing, the protruding portion 16 and the die main body mold 20 can be easily joined, and the number of assembling work can be significantly reduced. By supplying the brazing material from the hole 33 to the groove 34, the brazing material can be prevented from being insufficient, and the protrusion 16 and the die main body 20 can be reliably joined. Since a gap is formed between the coupling portion 17 and the molded portion 13 of the mold main body mold 20, the coupling portion 17 can be prevented from being joined to the mold main body mold 20 by the brazing material.

The protrusion 16 is assembled to the mold body 20 by disposing the mold body 20 at the lower side and joining the protrusion 16 from the upper side, but the present invention is not limited thereto. For example, the mold body 20 and the plurality of protrusions 16 may be positioned upside down, the mold body 20 may be arranged above, and the plurality of protrusions 16 may be joined from below to be assembled. However, when the plurality of protrusions 16 are joined from below and assembled, workability is deteriorated, and the plurality of protrusions 16 may be damaged.

The joining of the plurality of protrusions 16 and the die body mold 20 by brazing is not limited to the above-described form. For example, the hole 33 for inserting the brazing material may be provided not in the protrusion 16 but in the mold main body 20. In this case, the hole 33 penetrates the die body mold 20, and the brazing filler metal is put into the hole 33 of the die body mold 20.

The holes 33 provided in the plurality of protrusions 16 or the mold body 20 may not penetrate the protrusions 16 or the mold body 20. In this case, before the projection 16 is assembled to the die body mold 20, a brazing material is put into the hole 33 in advance in an amount necessary for brazing. By not penetrating the hole 33 provided in the protrusion 16 or the die main body mold 20, it is not necessary to close the hole 33 and finish the surface thereof after assembly.

(test for manufacturing tire mold 1)

In order to confirm the effect of the present invention, a manufacturing test of the tire mold 1 was performed.

First, the dimensions of the tire mold 1 are explained (see fig. 1). The inner diameter N (diameter) was about 3500mm, the height H of the split mold 10 was about 750mm, the width B of the reference surface 11 of the split mold 10 was about 450mm, the height P (protrusion size) of the protrusion 16 provided in the molding portion 13 was about 85mm, and the inclination angle T (inclination angle with respect to the mold width direction W1) of the back surface portion 14 was about 17 °. The split mold 10 is a casting (a material corresponding to carbon steel (SS 400)), and is manufactured by casting.

In the manufacturing test of the tire mold 1, the tire mold 1 was manufactured by the manufacturing method shown in the following comparative example 1, examples 1, 2, and 3, and the respective working periods were compared. The comparative work period is a work period for each of the production of a blank, the formation of a protrusion, the formation of an outer shape portion, the assembly, and the finishing. Further, the overall work periods obtained by summing up these work periods are also compared.

Comparative example 1

In comparative example 1, a tire mold 100 was manufactured by a conventional manufacturing method (fig. 20 to 25). That is, the blank of the split mold 110 is manufactured by near net casting with a finishing allowance of about 10mm (manufacturing of the blank). The blank is machined to form a plurality of protrusions 116 and contour portions (protrusion formation, contour portion formation). Next, the forming portion 114 and the plurality of protrusions 116 are machined, and the forming portion 114 and the plurality of protrusions 116 are finished (finished), thereby producing the split mold 110. The 18 split molds 110 are arranged in a ring shape and combined to manufacture the tire mold 100.

(example 1)

In example 1, a tire mold 1 was manufactured by the manufacturing method of embodiment 2 (fig. 8 to 13, fig. 7). That is, the annular protrusion blank 30 and the die body blank 31 are manufactured by casting (manufacturing of blanks). The annular projection blank 30 is subjected to machining by milling to form a plurality of projections 16 (formation of projections). Further, the die body blank 31 is machined to produce the die body 20 (outer shape portion formation). The plurality of protrusions 16 are joined and assembled to the mold body mold 20 (assembled). Next, the forming portion 13 and the plurality of protrusions 16 are machined, and the forming portion 13 and the plurality of protrusions 16 are finished (finished), thereby producing the split mold 10. The 18 split molds 10 are arranged in a ring shape and combined to manufacture the tire mold 1.

(example 2)

Example 2 is basically the same as example 1, but differs in the following points. That is, when the plurality of projections 16 are formed (formation of projections), the annular projection blank 30 is not machined by milling, but is cut by plasma cutting. In this way, the split molds 10 are produced, and 18 split molds 10 are arranged in a ring shape and combined to produce the tire mold 1.

(example 3)

Example 3 is basically the same as example 2, but differs in the following points. That is, when the protrusion 16 is joined and assembled to the die main body mold 20 (assembled), the protrusion 16 and the die main body mold 20 are joined by brazing as described in embodiment 3. The brazing material used was a Cu-30% Zn-based brazing material. In the brazing, by N₂The replacement furnace heats the mold body mold 20 and the plurality of protrusions 16 to 850 ℃ and then slowly cools. In this way, the split molds 10 are produced, and 18 split molds 10 are arranged in a ring shape and combined to produce the tire mold 1.

(test results)

Table 1 below shows the results of the manufacturing test of the tire mold 1.

In table 1, the overall construction period of the conventional production method of comparative example 1 is assumed to be 1, and an index for each construction period is calculated. The numerical value in (c) is an index of each work period when the production of the material of comparative example 1 is 1.

[ Table 1]

The overall work period indexes of examples 1, 2, and 3 were 0.79, 0.62, and 0.54, which are lower than the work period index of comparative example 1. That is, the production method shown in examples 1, 2, and 3 shortens the time required to produce the tire mold 1, compared to the conventional production method.

Description of the reference numerals

1 … tire mold, 10 … split mold, 11 … datum plane, 12 … end face, 13 … forming part, 14 … back face part, 15 … split face, 16 … protruding part, 17 … connecting part, 18 … upper end joint part, 19 … lower end joint part, 20 … mold main body, 21 … annular joint part, 30 … protruding blank, 31 … mold main body blank, 33 … hole, 34 … groove.

Claims

1. A method of manufacturing a tire mold having a plurality of divided molds arranged annularly along a tire circumferential direction,

the method for manufacturing the tire mold comprises the following steps:

forming a plurality of protruding parts connected by a connecting part;

manufacturing a main body mould of the mould;

assembling a plurality of protrusions to a mold main body mold; and

the connecting portion is removed from the plurality of protrusions, and a divided mold having a mold main body and the plurality of protrusions is manufactured.

2. The method of manufacturing a mold for a tire according to claim 1,

the step of forming the plurality of protruding portions includes a step of punching out unnecessary portions from the protruding blank to form the plurality of protruding portions and the coupling portion.

3. The method of manufacturing a mold for a tire according to claim 2,

the protruding blank is annular.

4. The method for manufacturing a tire mold according to any one of claims 1 to 3,

the assembly of the protrusion to the mold body is performed by: holes are provided in the protrusion or the die main body, and brazing filler metal is put into the holes to join the protrusion and the die main body by brazing.

5. The method for manufacturing a tire mold according to any one of claims 1 to 4,

when the plurality of protrusions are assembled to the mold main body mold, a gap is formed between the coupling portion and the mold main body mold.