JP2015202579A - Mold for tire vulcanization and method of producing tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve initial performance and appearance of a tire.SOLUTION: A mold for tire vulcanization comprises a cylindrical pattern formation member for forming a tread pattern on a surface of a tread part of an unvulcanized tire. The pattern formation member is divided into plural segments 26a along a peripheral direction of the pattern formation member. In the segment 26a, on a molding surface 28 directed to the inside of the pattern formation member in a radial direction, bone parts 29a, 29b protruding toward the inside in the radial direction and forming groove parts in the tread pattern, and recessed parts 30 recessed with respect to the bone parts 29a, 29b toward the outside in the radial direction and forming land parts in the tread pattern, are provided. On top surfaces of the bone parts 29a, 29b, side surfaces of the bone parts 29a, 29b or bottom surface of the recess part 30, slit parts 32a-32e for discharging air between the unvulcanized tire and the molding surface 28, are provided. The slit parts 32a-32e are disposed on the inside of an outer edge of a surface where these slit parts are provided.

Description

  The present invention relates to a tire vulcanization mold and a tire manufacturing method.

2. Description of the Related Art Conventionally, for example, a configuration described in Patent Document 1 below is known as a tire vulcanization mold (hereinafter referred to as “mold”) for vulcanizing an unvulcanized tire. This mold includes a cylindrical pattern forming member that forms a tread pattern on the surface of the tread portion of the unvulcanized tire. The pattern forming member is divided into a plurality of segments along the circumferential direction of the pattern forming member. In the segment, on the molding surface facing the inner side in the radial direction of the pattern forming member, a bone part protruding toward the inner side in the radial direction to form a groove part in the tread pattern, and a recess toward the outer side in the radial direction with respect to the bone part And a recess that forms a land portion in the tread pattern. A slit portion for exhausting air between the unvulcanized tire and the molding surface is provided on the bottom surface of the recess. The slit portion extends in the circumferential direction and opens toward both sides in the circumferential direction, and vertically cuts the bottom surface of the recess in the circumferential direction.
When an unvulcanized tire is vulcanized using this type of mold, air between the unvulcanized tire and the molding surface is discharged through the slit portion. Thereby, for example, the generation of tire bears is suppressed, so that product defects of tires are suppressed.
By the way, when the air in the mold is discharged through the slit portion, the rubber forming the unvulcanized tire flows into the slit portion together with the air, and as a result, spew is formed on the surface of the tire. Although this spew is removed from the tire, the root of the spew remains on the surface of the tread portion, and this root affects the initial performance and appearance of the tire.

Japanese Patent Laid-Open No. 11-300746

  Here, in the conventional mold, there is room for improvement in suppressing the influence of the spew on the initial performance and appearance of the tire and improving the initial performance and appearance of the tire.

  This invention is made | formed in view of the situation mentioned above, Comprising: It aims at providing the metal mold | die for tire vulcanization | cure which can improve the initial stage performance and external appearance property of a tire.

In order to solve the above problems, the present invention proposes the following means.
The tire vulcanization mold according to the present invention is a tire vulcanization mold for vulcanizing an unvulcanized tire, and is a cylindrical pattern that forms a tread pattern on the surface of the tread portion of the unvulcanized tire. The pattern forming member is divided into a plurality of segments along the circumferential direction of the pattern forming member, and the diameter of the molding surface facing the inside in the radial direction of the pattern forming member is the segment. A bone portion that protrudes inward in the direction and forms a groove portion in the tread pattern, and a recess that is recessed toward the outer side in the radial direction with respect to the bone portion and forms a land portion in the tread pattern, and A slit portion for exhausting air between the unvulcanized tire and the molding surface is provided on the top surface of the bone portion, the side surface of the bone portion or the bottom surface of the concave portion, and the slit portion is Characterized in that the slit portion is located inside the outer edge of the surface provided.
Here, the inner side of the outer edge refers to the inner side of the surrounding contour line forming one surface such as the top surface of the bone portion, the side surface of the bone portion, the bottom surface of the concave portion, or the like.

According to the present invention, the slit portion is located inside the outer edge of the surface provided with the slit portion (hereinafter referred to as “slit forming surface”), so that the conventional tire vulcanizing mold is used. In addition, the slit portion can be formed shorter in the slit forming surface than in the case where the slit portion cuts and crosses the slit forming surface. As a result, not only can the spew be elongated in the slit shape, but also the spew can be shortened, and the influence of the spew on the initial performance and appearance of the tire can be suppressed.
In addition, as described above, since the slit portion is located inside the outer edge of the slit forming surface, the slit portion can be freely and highly accurately formed in the slit forming surface without depending on the surface other than the slit forming surface. can do. As a result, the slit portion is formed in the slit forming surface by variously adjusting the position, shape, size, number, and the like. For example, the air that is difficult to exhaust in the tire vulcanizing mold is effective. It is possible to form a slit portion so that the spew is not noticeable on the surface of the tread portion, etc., and to improve the initial performance and appearance of the tire by the spew The influence can be further suppressed.
Further, as described above, since the slit portion can be formed with high accuracy in the slit forming surface, the elongated slit portion can be formed with high accuracy in the slit forming surface. This makes it possible to suppress the rubber forming the unvulcanized tire from flowing into the slit portion together with the air when the air in the tire vulcanizing mold is discharged through the slit portion. It is possible to suppress the protruding rubber flowing into the surface to a small amount and make it difficult to form spew on the surface of the tread portion. In addition, by suppressing the protruding rubber to a small amount in this way, it is possible to suppress the protruding rubber from remaining in the slit portion when the tire is removed from the tire vulcanizing mold. It is possible to suppress the occurrence of exhaust failure during vulcanization.

  Moreover, the said slit part may penetrate the said segment to the said radial direction, and may open in the back surface which faces the outer side of the said radial direction in the said segment.

  In this case, since the slit portion is opened on the back surface of the segment, the air in the tire vulcanization mold can be discharged toward the back surface of the segment, and can be effectively exhausted. it can.

  Further, the slit portion may be curved or bent in a sectional view of the segment along the radial direction.

  In this case, since the slit portion is curved or bent in the cross-sectional view, for example, it is possible to ensure the storage capacity of the protruding rubber in the slit portion as compared with the case where the slit portion is formed straight in the cross-sectional view. It becomes possible, and it is possible to suppress the protruding rubber from reaching the back surface of the segment through the slit portion.

  A circumferential groove extending in the circumferential direction and opening on both sides in the circumferential direction may be formed on the back surface of the segment, and the slit portion may be opened in the circumferential groove.

  In this case, since the slit portion is opened in the circumferential groove, the air discharged to the back surface of the segment can reach the end portion in the circumferential direction of the segment, and the exhaust gas can be exhausted more effectively. can do.

  The segment may be formed by a powder sintering method in which a powder layer made of a sinterable powder is sintered by laser light and laminated.

  In this case, since the segment is formed by the powder sintering method, like the slit part in this segment, the slit part located inside the outer edge of the slit forming surface is formed with high precision with less processing restrictions. can do. Thereby, it becomes possible to ensure the freedom degree of design of a slit part, and it can suppress reliably the influence on the initial performance and external appearance of a tire by a spew.

  The slit width of the slit portion may be 0.01 mm or greater and 0.4 mm or less.

  The tire manufacturing method according to the present invention is characterized in that a tire is formed by vulcanizing an unvulcanized tire using the tire vulcanization mold.

  According to this invention, since the tire is formed by vulcanizing the unvulcanized tire using the tire vulcanization mold, it becomes possible to suppress the influence of the spew on the initial performance and appearance of the tire. A tire excellent in initial performance and appearance can be formed.

  According to the present invention, the initial performance and appearance of the tire can be improved.

It is a fragmentary sectional view showing a tire vulcanizing device provided with a mold for tire vulcanization concerning one embodiment of the present invention. It is a perspective view of the pattern plate which comprises the metal mold | die for tire vulcanization | cure shown in FIG. It is an AA cross-sectional arrow view shown in FIG. It is a BB cross-sectional arrow view shown in FIG. It is sectional drawing of the pattern plate which comprises the metal mold | die for tire vulcanization | cure which concerns on the 1st modification of this invention. It is sectional drawing of the pattern plate which comprises the metal mold | die for tire vulcanization | cure which concerns on the 2nd modification of this invention. It is sectional drawing of the pattern plate which comprises the metal mold | die for tire vulcanization | cure which concerns on the 3rd modification of this invention.

Hereinafter, a tire vulcanizing apparatus including a tire vulcanizing mold according to an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the tire vulcanizing apparatus 10 includes a container 11 and a tire vulcanization mold (hereinafter referred to as “mold”) 20 attached to the container 11. The tire vulcanizing apparatus 10 forms a tire (vulcanized tire) by vulcanizing an unvulcanized tire disposed in the mold 20 by heating and pressurizing in the mold 20.

  The mold 20 includes a sector mold 21, an upper side mold 22, and a lower side mold 23. The sector mold 21 is disposed on the tread portion of the unvulcanized tire to mainly mold the tread portion, and the upper side mold 22 and the lower side mold 23 are respectively disposed on the sidewall portion of the unvulcanized tire. Mainly mold the sidewall.

  Here, the sector mold 21 is formed in a cylindrical shape, and the upper side mold 22 and the lower side mold 23 are both formed in an annular shape, and the respective central axes of the sector mold 21, the upper side mold 22, and the lower side mold 23. Are located on a common axis. Hereinafter, this common axis is referred to as a mold axis (axis of the pattern forming member), and a direction orthogonal to the mold axis is referred to as a radial direction (radial direction of the pattern forming member), and the direction of wrapping around the mold axis Is referred to as a circumferential direction (a circumferential direction of the pattern forming member).

  The sector mold 21 includes a holder 24 attached to the container 11 and a tread ring 25 held by the holder 24. Both the holder 24 and the tread ring 25 are formed in a cylindrical shape coaxial with the mold shaft. The tread ring 25 includes a pattern plate (pattern forming member) 26 located on the inner side in the radial direction, and an attachment 27 located on the outer side in the radial direction. The pattern plate 26 forms a tread pattern on the surface of the tread portion of the unvulcanized tire. The attachment 27 attaches the tread ring 25 to the holder 24. The thickness that is the size along the radial direction of the pattern plate 26 is smaller than the thickness of the attachment 27.

  Here, the holder 24 and the tread ring 25 are each divided into a plurality of pieces along the circumferential direction. Of these holders 24 and tread rings 25, in the tread ring 25, the pattern plate 26 and the attachment 27 are divided at equal intervals in the circumferential direction, and the tread ring 25 is divided along the circumferential direction. The body 25a is configured by combining a first segment (segment) 26a obtained by dividing the pattern plate 26 in the circumferential direction and a second segment 27a obtained by dividing the attachment 27 in the circumferential direction.

  The holder divided body 24a formed by dividing the holder 24 in the circumferential direction is, for example, the same size as the ring divided body 25a in the circumferential direction, and one holder divided body 24a holds one ring divided body 25a. May be. Further, for example, the holder divided body 24a may be formed larger in the circumferential direction than the ring divided body 25a, and one holder divided body 24a may hold a plurality of ring divided bodies 25a.

  As shown in FIG. 2, bone portions 29 a and 29 b and a concave portion 30 are provided on the molding surface 28 facing inward in the radial direction in the first segment 26 a. The bone parts 29a and 29b protrude from the molding surface 28 toward the inside in the radial direction, and form grooves in the tread pattern. The bone parts 29a and 29b are formed in a rectangular shape in a sectional view along the radial direction.

  The bone portions 29a and 29b are provided with a longitudinal bone portion 29a extending in the circumferential direction and a lateral bone portion 29b extending in the mold axis direction. A plurality of the vertical bone portions 29a are provided at intervals in the mold axis direction. A plurality of transverse bone portions 29b are provided at intervals in the circumferential direction, and among the plurality of transverse bone portions 29b, those located between the longitudinal bone portions 29a adjacent to each other in the mold axis direction are The bone parts 29a are connected to each other in the mold axis direction.

  The recess 30 is recessed outward in the radial direction with respect to the bone portions 29a and 29b (the top surfaces of the bone portions 29a and 29b), and forms a land portion in the tread pattern. A plurality of the concave portions 30 are provided in a portion located between the bone portions 29 a and 29 b on the molding surface 28. The plurality of recesses 30 are arranged side by side in the circumferential direction to form a recess row 30a, and the molding surface 28 is provided with a plurality of the recess rows 30a in the mold axis direction. The bottom surface of the recess 30 is formed in a rectangular shape, in the illustrated example, in a rectangular shape when the bottom surface (slit forming surface) is viewed from the front.

  A circumferential groove 31a extending in the circumferential direction and opening on both sides in the circumferential direction is formed on the back surface 31 facing the outside in the radial direction in the first segment 26a. A plurality of circumferential grooves 31a are arranged at intervals in the mold axis direction. The circumferential groove 31a is arranged so as to avoid a portion of the back surface 31 that is located outside the longitudinal bone portion 29a in the radial direction, and is shifted in the mold axis direction with respect to the longitudinal bone portion 29a. Both ends in the circumferential direction of the circumferential groove 31a reach the respective circumferential edges of the first segment 26a. The circumferential groove 31a is, for example, air in the mold 20 led into the circumferential groove 31a. Is discharged to reach the end of the first segment 26a in the circumferential direction.

  In the present embodiment, the top surfaces of the bone portions 29a and 29b, the side surfaces of the bone portions 29a and 29b, or the bottom surface of the recess 30 are slit portions 32a to 32a that exhaust air between the unvulcanized tire and the molding surface 28. 32e is provided, and the slit portions 32a to 32e are located inside the outer edge of the surface provided with the slit portions 32a to 32e (hereinafter referred to as “slit forming surface”). Here, the inner side of the outer edge means the inner side of the surrounding contour line forming the slit forming surface. That is, the slit portions 32a to 32e are accommodated in each slit forming surface, and terminate in the slit forming surface without vertically crossing or crossing the slit forming surface.

  The slit portions 32a to 32e are provided with side slit portions 32a provided on the side surfaces of the bone portions 29a and 29b and bottom surface slit portions 32b to 32e provided on the bottom surface of the concave portion 30, and the bone portions 29a are provided. , 29b are not provided with slit portions 32a to 32e.

The side slit portion 32a extends linearly within the side surfaces of the bone portions 29a and 29b and is formed in an I shape. In addition, in the slit width of the side slit part 32a, that is, in the side slit part 32a, the size along the direction orthogonal to the direction in which the side slit part 32a extends in the side surfaces (slit forming surfaces) of the bone parts 29a and 29b is For example, it may be 0.01 mm or more and 0.4 mm or less, and is preferably 0.01 mm or more and 0.2 mm or less.
The side slit portion 32a is disposed at the base end portion connected to the bottom surface of the recess 30 on the side surfaces of the bone portions 29a and 29b. The side slit portion 32a is provided in the lateral bone portion 29b among the plurality of bone portions 29a and 29b, and extends linearly in the mold axis direction.

  As shown in FIG. 3, the side slit portion 32a penetrates the bone portions 29a and 29b and opens on both side surfaces sandwiching the bone portions 29a and 29b. In the illustrated example, the side slit portion 32a penetrates the lateral bone portion 29b in the circumferential direction, and opens on both side surfaces facing the circumferential direction in the lateral bone portion 29b. The side slit portion 32a extends linearly and is formed in an I shape when viewed in cross section.

  As shown in FIG. 2, the bottom surface slit portions 32b to 32e include a first bottom surface slit portion 32b, a second bottom surface slit portion 32c, a third bottom surface slit portion 32d, and a fourth bottom surface slit portion 32e. It has been. The slit widths of these bottom slit portions 32b to 32e may be, for example, 0.01 mm or more and 0.4 mm or less, and preferably 0.01 mm or more and 0.2 mm or less.

  The first bottom slit portion 32 b extends linearly within the bottom surface of the recess 30 and is formed in an I shape. The first bottom slit portion 32 b extends in the circumferential direction and is disposed at the center of the bottom surface of the recess 30. The 1st bottom face slit part 32b is provided in each bottom face of a pair of recessed part 30 which pinches | interposes the horizontal bone part 29b in which the above-mentioned side surface slit part 32a was provided in the circumferential direction.

As shown in FIG. 4, the first bottom slit portion 32 b penetrates the first segment 26 a in the radial direction and opens on the back surface 31 of the first segment 26 a. In the present embodiment, the first bottom slit portion 32 b opens in the circumferential groove 31 a. doing. The first bottom slit portion 32b extends linearly and is formed in an I shape when viewed in cross section. The first bottom slit portion 32b has the same slit width over the entire length in the radial direction that is the depth direction, and the flow path cross-sectional area of the first bottom slit portion 32b is the depth direction of the first bottom slit portion 32b. It is the same over the entire length.
The second bottom slit portion 32c, the third bottom slit portion 32d, and the fourth bottom slit portion 32e as shown in FIG. 2 also have the first segment 26a in the radial direction in the same manner as the first bottom slit portion 32b. It penetrates and opens on the back surface 31 of the first segment 26a.

  The second bottom slit portion 32c extends linearly within the bottom surface of the recess 30 and is formed in an I shape. The second bottom slit portion 32c extends in the mold axis direction and is disposed adjacent to the horizontal bone portion 29b, and extends along the horizontal bone portion 29b. The second bottom slit portion 32c is provided on the bottom surface of the recess 30 constituting the recess row 30a located on both outer sides in the mold axis direction among the plurality of recess rows 30a arranged in the mold axis direction.

  Both the third bottom slit portion 32 d and the fourth bottom slit portion 32 e are disposed at the corners of the bottom surface of the recess 30. The third bottom slit portion 32 d is formed in an L shape within the bottom surface of the recess 30, and the fourth bottom slit portion 32 e is formed in an O shape within the bottom surface of the recess 30. In the illustrated example, the third bottom surface slit portion 32d and the fourth bottom surface slit portion 32e are arranged on the bottom surface of the same concave portion 30, and among the plurality of corner portions of the bottom surface, corners that are diagonal to each other. Located in the department.

  The third bottom slit portion 32d includes a circumferential slit 33a that extends linearly in the circumferential direction and an axial slit 33b that extends linearly in the mold axial direction, and is provided in the circumferential direction of the circumferential slit 33a. The end portion is connected to the end portion of the axial slit 33b in the mold axial direction. The circumferential slit 33a is disposed adjacent to the longitudinal bone portion 29a, and the axial slit 33b is disposed adjacent to the lateral bone portion 29b, and the circumferential slit 33a and the axial slit 33b are connected to each other. The formed part is arranged adjacent to the part where the longitudinal bone part 29a and the lateral bone part 29b are connected.

  In the tire vulcanizing apparatus 10, when an unvulcanized tire disposed in the mold 20 is vulcanized by heating and pressurizing in the mold 20, the air between the unvulcanized tire and the molding surface 28. Is discharged through the slit portions 32a to 32e. For example, the air is discharged from the mold 20 through the bottom slit portions 32b to 32e to the back surface 31 of the first segment 26a and discharged to the outside, or from the concave portion 30 of the mold 20 to the other concave portion through the side slit portion 32a. After being led out to 30, it is discharged to the outside through the bottom slit portions 32 b to 32 e formed on the bottom surface of the other recess 30.

  Here, the first segment 26a is a powder sintering method (a layered manufacturing method, for example) in which a powder layer made of a sinterable powder made of, for example, a metal material or a ceramic material is sintered by laser light. It is formed by rapid prototyping (Rapid prototyping). In the powder sintering method, the first segments 26a are formed by sequentially laminating powder layers that are heated and sintered by laser light irradiation.

An example of a method for producing the first segment 26a by the powder sintering method will be described. After a powder layer is formed with the above-mentioned powder in a chamber (not shown), the powder is produced by a laser device (local heating means) (not shown). The layer is heated to sinter. At this time, a control device (not shown) controls the optical path of the laser light emitted from the laser device based on, for example, the first segment 26a and the design drawing of the tire, and the first segment 26a of the powder layer The powder layer is sintered by scanning the portion with laser light.
Thereafter, a new powder layer is laminated on the powder layer, and the process of heating and sintering the new powder layer is repeated to form a laminated sintered body that becomes the first segment 26a. .

  In this powder sintering method, even when the slit portions 32a to 32e that fit within the slit forming surface are formed like the slit portions 32a to 32e of the first segment 26a described above, It is not necessary to simply sinter the portions to be the slit portions 32a to 32e (hereinafter referred to as “slit formation scheduled portions”). That is, in the case of the method exemplified above, the first segment 26a can be easily formed without having to scan the laser beam on the slit formation scheduled portion.

  Since the thickness of the pattern plate 26 is smaller than the thickness of the attachment 27, the production efficiency of the entire tread ring 25 is ensured even if the first segment 26a is formed by such a powder sintering method. That is, since the second segment 27a can have a simpler shape than the first segment 26a, the second segment 27a is formed with high accuracy by a method different from the powder sintering method such as casting. Can do.

  As described above, according to the mold 20 according to the present embodiment, the slit portions 32a to 32e are located inside the outer edges of the respective slit forming surfaces, so that the conventional tire vulcanization mold is used. As described above, the slit portions 32a to 32e can be formed shorter in the slit forming surface than in the case where the slit portion vertically cuts or crosses the slit forming surface. As a result, not only can the spew be elongated in the slit shape, but also the spew can be shortened, and the influence of the spew on the initial performance and appearance of the tire can be suppressed.

  Further, as described above, since the slit portions 32a to 32e are located inside the outer edge of the slit forming surface, the slit portions 32a to 32e are not dependent on the surfaces other than the slit forming surface, and within the slit forming surface. It can be formed freely and with high precision. As a result, the slit portions 32a to 32e are formed by adjusting the position, shape, size, number, etc. in the slit forming surface in various ways. For example, air that is difficult to be exhausted in the mold 20 is effective. It is possible to form the slit portions 32a to 32e so that the spew is not noticeable on the surface of the tread portion, and so on. The influence on performance and appearance can be further suppressed.

  In addition, since the first segment 26a is formed by a powder sintering method, the slit portions 32a to 32e positioned inside the outer edge of the slit forming surface are formed like the slit portions 32a to 32e in the first segment 26a. Therefore, it can be formed with high precision with less processing restrictions. Thereby, it becomes possible to ensure the freedom degree of design of the slit parts 32a-32e, and it can suppress reliably the influence on the initial performance and external appearance of a tire by a spew.

  Further, as described above, since the slit portions 32a to 32e can be formed with high accuracy in the slit forming surface, the elongated slit portions 32a to 32e can be formed with high accuracy in the slit forming surface. Thereby, when the air in this metal mold | die 20 is discharged | emitted through slit part 32a-32e, it becomes possible to suppress that the rubber | gum which forms an unvulcanized tire flows into slit part 32a-32e with air. Thus, the protruding rubber flowing into the slit portions 32a to 32e can be suppressed to a small amount, and it is difficult to form spew on the surface of the tread portion. Further, by suppressing the protruding rubber to a small amount in this manner, it is possible to suppress the protruding rubber from remaining in the slit portions 32a to 32e when the tire is removed from the mold 20, for example, It is possible to suppress the occurrence of exhaust failure during subsequent vulcanization.

  Moreover, when the slit widths of the slit portions 32a to 32e are 0.01 mm or more and 0.4 mm or less, it is possible to reliably suppress the influence of the spew on the initial performance and appearance of the tire. That is, when the slit width is smaller than 0.01 mm, it may be difficult to discharge the air in the mold 20. In addition, when the slit width is larger than 0.4 mm, the spew root portion remaining on the surface of the tread portion may greatly affect the initial performance and appearance of the tire.

Further, since the bottom slit portions 32b to 32e are opened on the back surface 31 of the first segment 26a, it becomes possible to discharge the air in the mold 20 toward the back surface 31 of the first segment 26a. It can exhaust effectively.
Furthermore, since the 1st bottom face slit part 32b is opened in the surrounding groove 31a, it is made to let the air discharged | emitted by the back surface 31 of the 1st segment 26a to the edge part of the circumferential direction of this 1st segment 26a. Can be exhausted more effectively.

  And, according to the tire manufacturing method for forming a tire by vulcanizing an unvulcanized tire using the mold 20, it becomes possible to suppress the influence on the initial performance and appearance of the tire due to spew, A tire excellent in initial performance and appearance can be formed.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  In the embodiment, the side slit portion 32a passes through the bone portions 29a and 29b and opens on both side surfaces sandwiching the bone portions 29a and 29b, but the present invention is not limited to this. For example, the side slit portion may penetrate the first segment in the radial direction, and may open to the back surface of the first segment.

Moreover, in this invention, the slit parts 32a-32e are not restricted to what was shown to the said embodiment.
For example, when the slit portion is viewed from the front of the slit forming surface on which the slit portion is formed, the I shape, the T shape, the C shape, the J shape, the O shape, the L shape, and the V shape. The shape or a part or all of the slits forming each of these shapes may be combined in a series.

Further, for example, like each first segment 26a of the mold according to the first modification, the second modification, and the second modification of the present invention shown in FIGS. 5 to 7, the slit portions 32f to 32h are arranged in the radial direction. It may be curved or bent in a sectional view along. For example, the slit portion 32f shown in FIG. 5 may be curved in a sectional view and formed in a J shape, or the slit portion 32g shown in FIG. 6 may be bent in a sectional view and formed in an L shape. Alternatively, it may be bent in a sectional view and formed into a V shape, like a slit portion 32h shown in FIG. Furthermore, the slit portion may have a shape in which a part or all of the J shape, the L shape, and the V shape are combined in series in a cross-sectional view.
In this case, since the slit portions 32f to 32h are curved or bent in the cross-sectional view, for example, compared to the case where the slit portion is formed straight in the cross-sectional view, the protruding rubber is accommodated in the slit portions 32f to 32h. Capacitance can be secured, and the protruding rubber can be prevented from reaching the back surface 31 of the first segment 26a through the slit portions 32f to 32h.

In the present invention, at least one slit portion is sufficient. Furthermore, in this invention, the top surface slit part as a slit part may be provided in the top surface of the bone part, and as this invention, at least 1 of the top surface of a bone part, the side surface of a bone part, and the bottom face of a recessed part. Other configurations in which one surface is provided with a slit portion located inside the outer edge of the surface can be appropriately employed.
Furthermore, in the present invention, the circumferential groove 31a may not be provided.

Moreover, in the said embodiment, although the tread ring 25 is provided with the attachment 27 and the pattern plate 26, this invention is not limited to this. For example, the tread ring may not be divided into the attachment and the pattern plate but may be formed by a single ring-shaped body formed integrally. In this case, the pattern forming member in the present invention can be constituted by the tread ring itself.
Furthermore, in the said embodiment, although the sector mold 21 is provided with the holder 24 and the tread ring 25, this invention is not limited to this. For example, the sector mold may not be divided into the holder and the tread ring, but may be formed by a single ring-shaped body formed integrally. In this case, the pattern forming member in the present invention can be constituted by the sector mold itself.

  In addition, it is possible to appropriately replace the constituent elements in the embodiment with known constituent elements without departing from the spirit of the present invention, and the above-described modified examples may be appropriately combined.

20 Tire vulcanization mold 26 Pattern plate (pattern forming member)
26a First segment (segment)
28 Molding surfaces 29a, 29b Bone 30 Recess 31 Back 31a Circumferential grooves 32a to 32h Slit

Claims (7)

A tire vulcanization mold for vulcanizing an unvulcanized tire,
A cylindrical pattern forming member that forms a tread pattern on the surface of the tread portion of the unvulcanized tire,
The pattern forming member is divided into a plurality of segments along the circumferential direction of the pattern forming member,
In the segment, on the molding surface facing the inner side in the radial direction of the pattern forming member, a bone part protruding toward the inner side in the radial direction to form a groove part in the tread pattern, and the radial direction with respect to the bone part And a recess that forms a land portion in the tread pattern that is recessed toward the outside of the tread pattern, and
The top surface of the bone part, the side surface of the bone part or the bottom surface of the recess is provided with a slit part for exhausting air between the unvulcanized tire and the molding surface,
The tire vulcanization mold, wherein the slit portion is located inside an outer edge of a surface provided with the slit portion. The tire vulcanization mold according to claim 1,
The tire vulcanization mold, wherein the slit portion penetrates the segment in the radial direction, and is opened on a back surface of the segment facing outward in the radial direction. The tire vulcanization mold according to claim 2,
The tire vulcanization mold, wherein the slit portion is curved or bent in a sectional view of the segment along the radial direction. A tire vulcanization mold according to claim 2 or 3,
On the back surface of the segment, a circumferential groove extending in the circumferential direction and opening on both sides of the circumferential direction is formed.
The tire vulcanization mold, wherein the slit portion is opened in the circumferential groove. The tire vulcanization mold according to any one of claims 1 to 4,
The segment is formed by a powder sintering method in which a powder layer made of a sinterable powder is sintered and laminated by laser light. A tire vulcanization mold according to any one of claims 1 to 5,
The slit width of the slit portion is 0.01 mm or more and 0.4 mm or less, and a tire vulcanization mold.   A tire manufacturing method comprising forming a tire by vulcanizing an unvulcanized tire using the tire vulcanizing mold according to claim 1.

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