JP2010280168A - Tire vulcanizing device and pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire vulcanizing device, which surely reduces a poor manufacturing due to the chipping of the block of a molded pneumatic tire under the condition that a through-hole is formed in each projection provided in an annular tread molding surface for molding a tread pattern and the pneumatic tire. <P>SOLUTION: The tire vulcanizing device 100 includes an annular tread molding surface 200 for molding the tread pattern on the tread 11 of a green tire 10. The tread molding surface 200 includes a plurality of projections 210. In the projection 210, the through-hole 211, which passes through from a first sidewall 210A to a second sidewall 210B, is formed. The through-hole 211 includes a small diameter region 212 and a large diameter region 213. The area (S1) of the small diameter region 212 normal to the extending direction L of the through-hole 211 is smaller that the area (S2) of the large diameter region 213 normal to the extending direction L of the through-hole 211. A straight line PL along the extending direction L of the through-hole 211 is leaning to the first sidewall 210A or to the second sidewall 210B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tire vulcanizer having an annular tread molding surface for molding a tread pattern on a tread of a pneumatic tire, and a pneumatic tire molded by the tire vulcanizer.

  2. Description of the Related Art Conventionally, a tire vulcanizing apparatus called a split mold that forms a tread pattern or a sidewall pattern while vulcanizing an unvulcanized pneumatic tire (so-called green tire) is known. In general, in a tire vulcanizer, an annular tread molding surface for molding a tread pattern on a tread of a raw tire is divided into a plurality (for example, nine). The tread molding surface has a plurality of convex portions that form grooves in the tread. A plurality of concave portions are formed between the convex portions by the convex portions.

  When a raw tire is vulcanized by such a tire vulcanizer, it is important to discharge the air between the tread and the tread molding surface of the raw tire to the outside. When the raw tire is vulcanized in a state where the air remains, a dent called a bear is generated in the block of the molded pneumatic tire.

  For this reason, in order to discharge air between the tread and the tread molding surface, a vent hole (vent hole) communicating from the tread molding surface to the outside is provided. As a result, spew is formed on the tread surface (grounding surface) of the molded pneumatic tire block by the tread rubber being pushed out from the vent hole. As a result, the spew formed on the tread surface of the block becomes conspicuous, and a step of removing the spew is necessary.

  Therefore, a technique is known in which a through hole (so-called cross vent hole) that penetrates from the one side wall forming one surface of the convex portion to the other side wall facing the one side wall is formed in the above-described convex portion. (For example, refer to Patent Document 1). According to this technique, the concave portion formed between the convex portions communicates with the adjacent concave portion via the through hole, and the air between the tread and the tread molding surface is hardly confined in the concave portion.

  Specifically, the tread rubber flows into the through-hole together with the air between the tread and the tread molding surface, thereby forming a bridge-shaped connection protrusion that connects adjacent blocks. When the tread molding surface is separated from the tread after vulcanization, the connecting projection is cut while being pulled by the projection.

  In such a technique, since air between the tread and the tread molding surface flows into the through hole from the recess, it is possible to suppress the occurrence of a recess in the block formed by the recess. Further, by forming the connecting protrusion between the blocks, the connecting protrusion is less noticeable than the case where the connecting protrusion is formed on the tread surface of the block, and the step of removing the connecting protrusion becomes unnecessary.

JP 10-44155 A (page 2-3, FIG. 6)

  However, the conventional tire vulcanizing apparatus described above has the following problems. In other words, after vulcanization, the boundary where the connecting protrusion and the side wall of the block are connected is cut, so that the side wall of the block of the molded pneumatic tire may be lost, resulting in poor manufacturing of the pneumatic tire. There was a problem that would occur.

  In view of the above, the present invention provides a tire addition that can reliably reduce manufacturing defects caused by chipping of blocks of a pneumatic tire to be molded when a through hole is formed in a convex portion provided on an annular tread molding surface for molding a tread pattern. An object of the present invention is to provide a pneumatic tire molded by a vulcanizing apparatus and a tire vulcanizing apparatus.

  In order to solve the above-described problems, the present invention has the following features. First, the first feature of the present invention has an annular tread molding surface (tread molding surface 200) for molding a tread pattern on a tread (tread 11) of an unvulcanized pneumatic tire (raw tire 10). The tread of the unvulcanized pneumatic tire has an annular tread molding surface for molding a tread pattern, and the tread molding surface has a plurality of convex portions (convex portions 210) that form grooves (grooves 11A) in the tread. Have The convex part forms a first side wall (first side wall 210A) that forms one side wall of the convex part, and a second side wall (second side) that forms the other side wall of the convex part and faces the first side wall. A side wall 210B), and the convex portion is formed with a through-hole penetrating from the first side wall to the second side wall. 1st area | region (small diameter area | region 212) including the 1st opening part (small diameter opening part 212A) located in the 1st side wall side and opening to the said 1st side wall, and located in the said 2nd side wall side, A second region (large-diameter region 213) including a second opening (large-diameter opening 213A) is provided, and is orthogonal to the extending direction (extending direction L) of the through-hole (through-hole 211). The area (S1) of the first region in the cross section to be measured is in the cross section orthogonal to the extending direction of the through hole. The summary is that the straight line (straight line PL) that is smaller than the area (S2) of the second region and extends along the extending direction of the through hole is inclined with respect to the first side wall or the second side wall. .

  According to this feature, the area of the first region in the cross section orthogonal to the extending direction of the through hole is smaller than the area of the second region in the cross section orthogonal to the extending direction of the through hole. According to this, in the pneumatic tire formed by the tire vulcanizing device, a connecting projection composed of a thin portion and a thick portion is formed.

  The straight line along the extending direction of the through hole is inclined with respect to the first side wall or the second side wall. According to this, in the pneumatic tire formed by the tire vulcanizing device, the straight line along the extending direction of the connecting protrusion is inclined with respect to the first side wall or the second side wall. For this reason, compared with the case where the straight line is perpendicular to the first side wall or the second side wall, it becomes easier to increase the area of the connecting portion (first connecting portion) connected to the first side wall in the connecting protrusion. The part is more difficult to cut.

  As described above, when the vulcanized pneumatic tire is taken out from the tire vulcanizer (hereinafter, when the tire is taken out), if the connecting protrusion is pulled by the convex part, the thick part or the thin part of the side wall and the connecting protrusion A part of the thin portion of the connecting projection is reliably cut without cutting the boundary where the two are connected. Therefore, it is possible to reliably reduce manufacturing defects due to chipping of the molded pneumatic tire block.

  A second feature of the present invention relates to the first feature of the present invention, and is an angle (inclination angle β) formed by the straight line along the extending direction of the through hole and the first side wall or the second side wall. ) Is 30 to 90 degrees.

  A third feature of the present invention relates to the first or second feature of the present invention, and is summarized in that the first opening opens so as to spread with respect to the first side wall.

  A fourth feature of the present invention relates to the first to third features of the present invention, wherein the through hole is provided between the first opening and the second opening, and the first opening It further has a third region (intermediate region 214) connecting the second opening, and an angle formed by a surface forming the third region and a surface forming the first opening (connection angle (θ)). ) Is 90 to 150 degrees.

  A fifth feature of the present invention relates to the first to fourth features of the present invention, wherein an area (S3) of the first opening along the first side wall is orthogonal to the extending direction of the through hole. The gist is that it is larger than the area (S1) of the first region in the cross section.

  A sixth feature of the present invention is that a plurality of blocks are formed by a plurality of grooves, from a first side wall forming one of the blocks to a second side wall forming the other block adjacent to the one block. A pneumatic tire (for example, pneumatic tire 1) provided with a continuous connecting protrusion (connecting protrusion 13), wherein the connecting protrusion is located on the first side wall side and is connected to the first side wall. A first portion (small-diameter portion 14) including a first connecting portion (small-diameter connecting portion 14A), and a second connecting portion (large-diameter connecting portion 15A) located on the second side wall and connected to the second side wall. An area (S10) of the first portion in a cross section perpendicular to the extending direction of the connecting protrusion is orthogonal to the extending direction of the connecting protrusion. Smaller than the area (S20) of the second portion in the cross section The gist of the invention is that the area (S30) of the first connecting portion along the first side wall is larger than the area (S10) of the first portion in a cross section orthogonal to the extending direction of the connecting protrusion. .

  According to the characteristics of the present invention, when a through hole is formed in a convex portion provided on an annular tread molding surface for molding a tread pattern, it is possible to reliably reduce manufacturing defects due to chipping of a block of a pneumatic tire to be molded. A tire vulcanizer and a pneumatic tire molded by the tire vulcanizer can be provided.

FIG. 1 is a cross-sectional view showing a part of a tire vulcanizing apparatus 100 according to this embodiment. FIG. 2 is a perspective view showing one segment of the tire vulcanizing apparatus 100 according to the present embodiment. FIG. 3 is a cross-sectional view showing the convex portion 210 according to the present embodiment. FIG. 4 is a flowchart showing the tire manufacturing method according to the present embodiment. FIG. 5 is a cross-sectional view showing a part of the pneumatic tire 1 according to the present embodiment. FIG. 6 is a side / top sectional view showing the pneumatic tire 1 according to the present embodiment after being taken out. FIG. 7 is an enlarged cross-sectional view showing a part of the tread molding surface 200A according to the first modification. FIG. 8 is a top view showing the convex portion 210 of the tread molding surface 200A according to the first modification. FIG. 9 is an enlarged cross-sectional view illustrating a part of the tread molding surface 200B according to the second modification. FIG. 10 is an enlarged cross-sectional view illustrating a part of the tread 11 of the pneumatic tire 1B according to the second modification. FIG. 11 is a cross-sectional view from the side surface of the convex portion 210 of the tread molding surface 200C according to the third modification. FIG. 12 is a cross-sectional view from the side of the block 12 of the pneumatic tire 1 </ b> C according to the third modification.

  Next, embodiments of a tire vulcanizing apparatus and a pneumatic tire molded by the tire vulcanizing apparatus according to the present invention will be described with reference to the drawings. Specifically, (1) configuration of tire vulcanizer, (2) configuration of tread molding surface, (3) tire manufacturing method, (4) modification example, (5) comparative evaluation, (6) action / effect, (7) Other embodiments will be described.

  In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(1) Configuration of Tire Vulcanizing Device First, the configuration of the tire vulcanizing device 100 according to the present embodiment will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing a part of a tire vulcanizing apparatus 100 according to this embodiment. FIG. 2 is a perspective view showing one segment of the tire vulcanizing apparatus 100 according to the present embodiment.

  As shown in FIG. 1, the tire vulcanizer 100 forms a tread pattern, a sidewall pattern, and the like on the raw tire 10 while vulcanizing an unvulcanized pneumatic tire (so-called green tire 10). The tire vulcanizing apparatus 100 includes a side mold 110 and a sector mold 120.

(1-1) Side Mold The side mold 110 forms a sidewall pattern or the like on the raw tire 10. As shown in FIG. 1, the side mold 110 includes a lower mold 111 and an upper mold 112.

  The lower mold 111 is fixed to a lower container 140A positioned below the lower mold 111, and the raw tire 10 is placed thereon. The lower mold 111 is formed with an inner peripheral surface 111 a that forms a pattern or the like on one sidewall of the raw tire 10.

  The upper mold 112 is fixed to the upper container 140B located above the upper mold 112. The upper mold 112 moves in the tread width direction W. The upper mold 112 is formed with an inner peripheral surface 112 a that forms a pattern or the like on the other sidewall of the raw tire 10.

(1-2) Sector Mold The sector mold 120 forms a tread pattern. The sector mold 120 includes an outer ring 121 and a plurality of segments 122. The outer ring 121 has an annular shape and moves along the tread width direction W (in the present embodiment, the vertical direction). The plurality of segments 122 are divided into a plurality (for example, nine) and move along the tire radial direction R. That is, the segment 122 radially expands along the tire radial direction R.

  The segment 122 has an annular tread molding surface 200 that molds a tread pattern on the tread 11 of the raw tire 10. The details of the tread molding surface 200 will be described later.

(2) Configuration of Tread Molding Surface Next, the configuration of the tread molding surface 200 according to the present embodiment will be described with reference to FIGS. FIG. 3A is a cross-sectional view taken along the line AA in FIG. FIG.3 (b) is BB sectional drawing of Fig.3 (a).

  As shown in FIGS. 1 and 2, the tread molding surface 200 has a plurality of convex portions 210. The convex part 210 forms a groove 11 </ b> A (for example, a circumferential groove or a width groove) in the tread 11 of the raw tire 10. The convex portion 210 has a rectangular shape in a cross section orthogonal to the longitudinal direction of the convex portion 210. A recess 220 is formed by the protrusions 210 between the plurality of protrusions 210. The recess 220 forms the block 12 partitioned by the groove 11A.

  Here, as shown in FIG. 3, the convex portion 210 includes a first side wall 210A that forms one side wall of the convex portion 210 and a second side wall that forms the other side wall of the convex portion 210 and faces the first side wall 210A. 2 side walls 210B. The convex portion 210 is formed with a cylindrical through hole 211 (so-called cross vent hole) penetrating from the first side wall 210A to the second side wall 210B. Specifically, the through-hole 211 is provided with a small diameter region 212 (first region) and a large diameter region 213 (second region).

  The small diameter region 212 is located on the first side wall 210A side and has a constant diameter. The small-diameter region 212 includes a small-diameter opening 212A (first opening) that opens in the first side wall 210A. On the other hand, the large diameter region 213 is located on the second side wall 210B side and has a constant diameter. The large-diameter region 213 includes a large-diameter opening 213A (second opening) that opens to the second side wall 210B. The small-diameter region 212 and the large-diameter region 213 are connected in a right-angle shape (α1 in FIG. 3).

  In the present embodiment, the length (L1) of the small diameter region 212 in the extending direction L of the through hole 211 is 70% of the length (L2) of the through hole 211 in the extending direction L of the through hole 211. It is. That is, the length (L3) of the large diameter region 213 in the extending direction L of the through hole 211 is 30% with respect to the length (L2) of the through hole 211 in the extending direction L of the through hole 211.

  Here, the area (S1) of the small diameter region 212 in the cross section orthogonal to the extending direction L of the through hole 211 is larger than the area (S2) of the large diameter region 213 in the cross section orthogonal to the extending direction L of the through hole 211. small. That is, the diameter of the small diameter region 212 is smaller than the diameter of the large diameter region 213. In particular, the diameter of the small diameter region 212 is preferably 0.6 to 1.0 mm or less with respect to the diameter of the large diameter region 213.

  Further, the area (S3) of the small-diameter opening 212A along the first side wall 210A is larger than the area (S1) of the small-diameter region 212 in the cross section orthogonal to the extending direction L of the through hole 211. The area of the large-diameter opening 213A along the second side wall 210B is the same as the area (S2) of the large-diameter region 213 in the cross section orthogonal to the extending direction L of the through hole 211.

  The straight line PL along the extending direction L of the through hole 211 is perpendicular to the first side wall 210A or the second side wall 210B in the side view of the convex portion 210 (see FIG. 3A) (FIG. 3A). Β). Further, the straight line PL is inclined with respect to the first side wall 210A or the second side wall 210B in a top view of the convex portion 210 (see FIG. 3B). Specifically, the straight line PL has an inclination angle (γ in FIG. 3B) formed by the straight line PL and the first side wall 210A or the second side wall 210B in the top view of the convex portion 210 is 30 to 90 degrees. is there.

(3) Tire Manufacturing Method Next, a tire manufacturing method using the tire vulcanizing apparatus 100 described above will be described with reference to the drawings. FIG. 4 is a flowchart showing the tire manufacturing method according to the present embodiment. Fig.5 (a) is an expanded sectional view which shows the time of vulcanization | cure of the pneumatic tire 1 which concerns on this embodiment. FIG.5 (b) is an expanded sectional view which shows the time of taking out the pneumatic tire 1 which concerns on this embodiment. Fig.6 (a) is side surface sectional drawing which shows after taking out the pneumatic tire 1 which concerns on this embodiment. FIG. 6B is a top cross-sectional view showing the pneumatic tire 1 according to the present embodiment after being taken out.

  As shown in FIG. 4, the tire manufacturing method includes a tire housing process, a tire vulcanization process, and a tire take-out process.

(3-1) Tire housing process In the tire housing process S1, the raw tire 10 is housed in the tire vulcanizing apparatus 100 described above. Specifically, the raw tire 10 is placed on the lower mold 111, and the sector mold 120 and the upper mold 112 move so as to approach the raw tire 10.

(3-2) Tire Vulcanization Step In the tire vulcanization step S2, the pneumatic tire 1 is molded by subjecting the raw tire 10 to vulcanization treatment under predetermined conditions in the tire vulcanizer 100. At this time, air between the tread 11 of the raw tire 10 and the tread molding surface 200 of the sector mold 120 that is expanded from the inner peripheral surface by the bladder 160 (see FIG. 1) flows into the through hole 211. At the same time, the tread rubber forming the tread 11 of the green tire 10 also flows into the through-hole, and a bridge-like connecting protrusion 13 that connects the adjacent blocks 12 is formed.

  Specifically, as shown in FIGS. 5 and 6, the connecting protrusion 13 has a small diameter portion 14 (first portion) and a large diameter portion 15 (second portion). The small diameter portion 14 is located on the side wall 12A (first side wall) side of one block 12 and has a constant diameter. The small diameter portion 14 includes a small diameter connection portion 14A (first connection portion) that is connected to the side wall 12A. On the other hand, the large diameter portion 15 is located on the side wall 12B (second side wall) side of the other block 12, and has a constant diameter. The large diameter portion 15 includes a large diameter connection portion 15A (second connection portion) that is connected to the side wall 12B.

  The area (S10) of the small diameter portion 14 in the cross section orthogonal to the extending direction L of the connecting protrusion 13 is thinner than the area (S20) of the large diameter portion 15 in the cross section orthogonal to the extending direction L of the connecting protrusion 13. . That is, the diameter of the small diameter portion 14 corresponding to the diameter of the small diameter region 212 is smaller than the diameter of the large diameter portion 15 corresponding to the diameter of the large diameter region 213. In particular, the diameter of the small diameter region 212 is preferably 0.6 to 1.0 mm or less with respect to the diameter of the large diameter portion 15.

  Further, the area (S30) of the small-diameter connecting portion 14A along the side wall 12A of one block 12, that is, the boundary area between the side wall 12A and the small-diameter portion 14 is a cross section orthogonal to the extending direction L of the connecting protrusion 13. It is larger than the area (S10) of the small-diameter portion 14 at. Further, the straight line SL along the extending direction L of the connecting protrusion 13 is inclined with respect to the side wall 12A or the side wall 12B (θ in FIG. 6B).

(3-3) Tire Extraction Step In the tire extraction step S3, the sector mold 120 is radially expanded along the tire radial direction R, so that the pneumatic tire 1 vulcanized by the tire vulcanizer 100 is added to the tire. Take out from the sulfur apparatus 100. At this time, as shown in FIG. 5B, the connecting protrusion 13 is pulled by the first side wall 210A forming the convex portion 210, and the small-diameter connecting portion 14A is cut. Further, as shown in FIG. 6, a small-diameter connecting portion 14A is connected to the side wall 12A, and a large-diameter connecting portion 15A is connected to the side wall 12B.

(4) Modification Example The tire vulcanizing apparatus 100 according to the embodiment described above may be modified as follows. Specifically, Modification Example 1 and Modification Example 2 will be described. In addition, the same code | symbol is attached | subjected to the same part as the tire vulcanizing apparatus 100 which concerns on embodiment mentioned above, and a different part is mainly demonstrated.

(4-1) Modification 1
First, a tire vulcanizing apparatus 100A according to Modification 1 will be described with reference to the drawings. FIG. 7 is a cross-sectional view from the top surface of the convex portion 210 of the tread molding surface 200A according to the first modification. FIG. 8 is a cross-sectional view from the top surface of the tread 11 of the pneumatic tire 1A according to the first modification.

  In the embodiment described above, the small diameter region 212 has a constant diameter. On the other hand, in the first modification, as shown in FIG. 7, the small diameter region 212 may not have a constant diameter.

  Specifically, among the small-diameter regions 212, the small-diameter opening region 212S including the small-diameter opening 212A opens so as to spread with respect to the first side wall 210A. The small-diameter opening region 212S is located in a region that is 1/5 of the length (L3) of the small-diameter region 212 in the extending direction L of the through hole 211.

  That is, as shown in FIG. 8, in the pneumatic tire 1 </ b> A formed by the tire vulcanizing apparatus 100 </ b> A, the small-diameter connection region 14 </ b> S including the small-diameter connection portion 14 </ b> A in the small-diameter portion 14 in the top view of the block 12. It connects so that it may spread with respect to the side wall 12A.

  Here, in the small-diameter region 212, it is not always necessary to open only the small-diameter opening region 212S so as to expand with respect to the first side wall 210A, and the entire small-diameter region 212 is open so as to expand with respect to the first side wall 210A. Also good.

(4-2) Modification 2
Next, a tire vulcanizing apparatus 100B according to Modification 2 will be described with reference to the drawings. FIG. 9 is a cross-sectional view from the upper surface of the convex portion 210 of the tread molding surface 200B according to the second modification. FIG. 10 is a cross-sectional view from the top surface of the tread 11 of the pneumatic tire 1B according to the second modification.

  In the above-described embodiment, the through hole 211 is provided with the small diameter region 212 and the large diameter region 213. On the other hand, in the modified example 2, as shown in FIG. 9, the through hole 211 is further provided with an intermediate region 214 (third region) in addition to the small diameter region 212 and the small diameter region 212.

  Specifically, the intermediate region 214 is located between the small diameter region 212 and the large diameter region 213 and connects the small diameter region 212 and the large diameter region 213. The connection angle (α2) formed by the outer peripheral surface forming the intermediate region 214 and the outer peripheral surface forming the small-diameter region 212 is 90 to 150 degrees.

  That is, as shown in FIG. 10, the pneumatic tire 1 </ b> B formed by the tire vulcanizing apparatus 100 </ b> B further includes a medium diameter portion 16 in addition to the small diameter portion 14 and the large diameter portion 15. The medium diameter portion 16 is located between the small diameter portion 14 and the large diameter portion 15 and connects the small diameter portion 14 and the large diameter portion 15. The connection angle (α3) formed by the outer surface forming the medium diameter portion 16 and the outer surface forming the small diameter portion 14 is 90 to 150 degrees.

(4-3) Modification 3
Next, a tire vulcanizing apparatus 100C according to Modification 3 will be described with reference to the drawings. FIG. 11 is a cross-sectional view from the side surface of the convex portion 210 of the tread molding surface 200C according to the third modification. FIG. 12 is a cross-sectional view from the side of the block 12 of the pneumatic tire 1 </ b> C according to the third modification.

  In the embodiment described above, the convex portion 210 has a rectangular shape in a cross section orthogonal to the longitudinal direction of the convex portion 210. On the other hand, in the modified example 3, as shown in FIG. 11, the convex portion 210 has a trapezoidal shape in a cross section orthogonal to the longitudinal direction of the convex portion 210.

  That is, as shown in FIG. 12, the block 12 of the pneumatic tire 1 </ b> C formed by the tire vulcanizing apparatus 100 </ b> C has a trapezoidal shape in a cross section from the side surface of the block 12.

(5) Comparative Evaluation Next, in order to further clarify the effects of the present invention, comparative evaluation performed using tire vulcanizing apparatuses according to the following comparative examples and examples will be described. Specifically, (5-1) Configuration of each tire vulcanizer and (5-2) Evaluation result will be described. In addition, this invention is not limited at all by these examples.

(5-1) Configuration of Each Tire Vulcanizing Apparatus First, tire vulcanizing apparatuses according to Comparative Examples 1 and 2 and Examples 1 and 2 will be briefly described. The data relating to the tire vulcanizer was measured under the following conditions.

・ Tire size to vulcanize: 195 / 65R15
-Number of through-holes (cross vent holes): 210 In the tire vulcanizing apparatus according to Comparative Example 1, the through-hole penetrates the convex portion with a constant diameter. In the tire vulcanizing apparatus according to Comparative Example 2, the through hole has a small diameter opening and a large diameter opening. In the tire vulcanizing apparatus according to Comparative Example 2, the through hole is formed at a right angle to the side wall forming the convex portion when the convex portion is viewed from above.

The tire vulcanizing apparatus 100 according to Example 1 is described in the embodiment. The tire vulcanizing apparatus according to the first embodiment is a combination of the first modification and the second modification. The details of each tire vulcanizer are as shown in Table 1.

(5-2) Evaluation Results Next, the evaluation results of the pneumatic tire molded by the tire vulcanizing apparatus according to the comparative example and Examples 1 to 3 described above will be described with reference to Table 1.

  100 pneumatic tires were molded by each tire vulcanizing apparatus, and the incidence of manufacturing defects due to chipped blocks was calculated. As a result, as shown in Table 1, the pneumatic tire molded by the tire vulcanizing apparatus according to Examples 1 and 2 is compared with the pneumatic tire molded by the tire vulcanizing apparatus according to Comparative Examples 1 and 2. It has been found that the incidence of manufacturing defects due to chipping of the blocks is reduced.

(6) Action / Effect In the embodiment described above, the area (S1) of the small diameter region 212 is smaller than the area (S2) of the large diameter region 213. According to this, in the pneumatic tire 1 formed by the tire vulcanizing apparatus 100, the area (S10) of the small diameter portion 14 is smaller than the area (S20) of the large diameter portion 15.

  The straight line PL along the extending direction L of the through hole 211 is inclined with respect to the first side wall 210A or the second side wall 210B. According to this, in the pneumatic tire 1 formed by the tire vulcanizing device 100, the straight line SL along the extending direction L of the connecting protrusion 13 is inclined with respect to the side wall 12A or the side wall 12B. For this reason, compared with the case where the straight line SL is perpendicular to the side wall 12A or the side wall 12B, the area (S30) of the small-diameter coupling portion 14A is easily increased, and the small-diameter coupling portion 14A is further less likely to be cut.

  As described above, when the connecting protrusion 13 is pulled by the convex portion 210 when the tire is taken out, a part of the small diameter region 212 is reliably cut without cutting the large diameter connecting portion 15A and the small diameter connecting portion 14A. . Therefore, it is possible to reliably reduce manufacturing defects caused by the lack of the block 12 of the molded pneumatic tire 1.

  By the way, if the connection protrusion 13 is left in the tire vulcanizing apparatus 100, the connection protrusion 13 may adhere as a foreign matter to the raw tire 10 to be vulcanized and molded. However, in this embodiment, a part of the small diameter region 212 is cut, the small diameter connecting portion 14A is connected to the side wall 12A, and the large diameter connecting portion 15A is connected to the side wall 12B. For this reason, it is possible to prevent the connection protrusion 13 from being left in the tire vulcanizing apparatus 100 (in the through hole 211). Therefore, it is possible to reliably prevent the connection protrusion 13 from adhering to the green tire to be vulcanized and molded as foreign matter.

  In the embodiment, in a top view of the convex portion 210, an inclination angle formed by the straight line PL along the extending direction L of the through hole 211 and the first side wall 210A or the second side wall 210B (γ in FIG. 3B). Is 30 to 90 degrees. If the inclination angle (β) is smaller than 30 degrees, the small diameter connecting portion 14A may be caught by the convex portion 210 when the tire is taken out, and the block 12 (side wall 12A) may be missing.

  In the embodiment, the area (S3) of the small diameter opening 212A along the first side wall 210A is larger than the area (S1) of the small diameter region 212. According to this, in the pneumatic tire 1 formed by the tire vulcanizing apparatus 100, the area (S30) of the small diameter connecting portion 14A along the side wall 12A of the block 12 is larger than the area (S10) of the small diameter portion 14. Become.

  In the embodiment (Modification 1), among the small-diameter regions 212, the small-diameter opening region 212S including the small-diameter opening 212A opens so as to expand with respect to the first side wall 210A. That is, among the small diameter connecting portions 14A, among the small diameter portions 14, the small diameter connecting regions 14S including the small diameter connecting portions 14A are also connected so as to spread toward the side wall 12A. According to this, the area (S30) of the small-diameter coupling portion 14A further increases as the small-diameter coupling region 14S expands. For this reason, it becomes difficult to cut | disconnect with the small diameter connection part 14A, and a part of small diameter part 14 is cut | disconnected reliably.

  In the embodiment (Modification 2), the connection angle (θ) formed by the outer peripheral surface forming the intermediate region 214 and the outer peripheral surface forming the small-diameter region 212 is 90 to 150 degrees. That is, the connection angle (α3) formed by the outer surface forming the medium diameter portion 16 and the outer surface forming the small diameter portion 14 is 90 to 150 degrees. If the connection angle (β, α3) is smaller than 150 degrees, the length in the extending direction L of the medium diameter portion 16 becomes too long, and it is difficult to secure the length in the extending direction L of the small diameter portion 14. The small diameter portion 14 is difficult to be cut.

(7) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  For example, the embodiment of the present invention can be modified as follows. Specifically, in the embodiment, the tire vulcanizing apparatus 100 has been described as molding the pneumatic tire 1 by vulcanizing the raw tire 10, but the present invention is not limited thereto, and the pneumatic tire is not limited thereto. Tires other than 1 (for example, solid tires) may be formed.

  Further, the tire vulcanizing apparatus 100 has been described as a so-called segment type in which the sector mold 120 is divided into a plurality of pieces, but is not limited thereto, and is divided into two along the tread width direction. A two-piece type may be used. That is, of course, the configuration of the tire vulcanizing apparatus 100 can be appropriately changed according to the purpose.

  Moreover, although the length (L1) of the small diameter area | region 212 in the through-hole 211 was demonstrated as 70% with respect to the length (L2) of the through-hole 211, it is not limited to this, For example, It may be 50% with respect to the length (L2) of the through-hole 211, and can be appropriately changed according to the purpose.

  Moreover, although the small diameter area | region 212 and the large diameter area | region 213 in the through-hole 211 were demonstrated as what has a fixed diameter, it is not limited to this, Each diameter may be changing. That is, the diameters of the small-diameter portion 14 and the large-diameter portion 15 in the connection protrusion 13 may also change.

  Moreover, although the through-hole 211 was demonstrated as what is formed in the cylindrical shape penetrated from the 1st side wall 210A to the 2nd side wall 210B, it is not limited to this, It forms other than a cylindrical shape (for example, prism). May be.

  Further, the straight line PL along the extending direction L of the through hole 211 is described as being inclined with respect to the first side wall 210A or the second side wall 210B in the top view of the convex portion 210 (see FIG. 3B). However, the present invention is not limited to this, and may be perpendicular to the first side wall 210A or the second side wall 210B. In this case, the straight line PL may be inclined in a side view of the convex portion 210 (see FIG. 3A).

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1,1A, 1B, 1C ... Pneumatic tire, 10 ... Raw tire, 11 ... Tread, 11A ... Groove, 12 ... Block, 12A, 12B ... Side wall, 13 ... Connection protrusion, 13 ... Border, 14 ... Small diameter part ( 1st portion), 14A ... small diameter connecting portion (first connecting portion), 14S ... small diameter connecting region, 15 ... large diameter portion (second portion), 15A ... large diameter connecting portion (second connecting portion), 16 ... medium Diameter portion, 100, 100A, 100B ... tire vulcanizer, 110 ... side mold, 111 ... lower mold, 111a ... inner peripheral surface, 112 ... upper mold, 112a ... inner peripheral surface, 120 ... sector mold, 121 ... outer Ring, 122 ... segment, 140A ... lower container, 140B ... upper container, 160 ... bladder, 200, 200A, 200B, 200C ... tread molding surface, 210 ... convex, 210A ... first Wall, 210B ... second side wall, 211 ... through hole, 212 ... small diameter region (first region), 212A ... small diameter opening (first opening), 212S ... small diameter opening region, 213 ... large diameter region, 213A ... large Diameter opening (second opening), 214 ... intermediate region (third region), 220 ... concave

Claims (6)

It has an annular tread molding surface that forms a tread pattern on the tread of an unvulcanized pneumatic tire,
The tread molding surface has a plurality of convex portions that form grooves in the tread,
The convex portion is
A first side wall forming one side wall of the convex part;
Forming the other side wall of the convex portion and having at least a second side wall facing the first side wall;
The convex portion is a tire vulcanizing device in which a through-hole penetrating from the first side wall to the second side wall is formed,
In the through hole,
A first region located on the first sidewall side and including a first opening opening in the first sidewall;
A second region located on the second side wall side and including a second opening opening in the second side wall;
The area of the first region in the cross section orthogonal to the extending direction of the through hole is smaller than the area of the second region in the cross section orthogonal to the extending direction of the through hole,
A tire vulcanizer in which a straight line along the extending direction of the through hole is inclined with respect to the first side wall or the second side wall.   2. The tire vulcanizing apparatus according to claim 1, wherein an angle formed between the straight line along the extending direction of the through hole and the first side wall or the second side wall is 30 to 90 degrees.   The tire vulcanizing apparatus according to claim 1 or 2, wherein the first opening opens so as to spread with respect to the first side wall. In the through hole,
A third region located between the first opening and the second opening and connecting the first opening and the second opening is provided;
The tire vulcanizing apparatus according to any one of claims 1 to 3, wherein an angle formed between a surface forming the third region and a surface forming the first opening is 90 to 150 degrees.   The area of the said 1st opening part along the said 1st side wall is larger than the area of the said 1st area | region in the cross section orthogonal to the extension direction of the said through-hole. Tire vulcanizer. A plurality of blocks are formed by a plurality of grooves, and an air provided with a connecting projection that extends from a first side wall that forms one of the blocks to a second side wall that forms the other block adjacent to the one block. A tire containing
The connecting projection is
A first portion located on the first side wall side and including a first connecting portion connected to the first side wall;
A second portion including a second connecting portion located on the second side wall and connected to the second side wall;
The area of the first portion in the cross section orthogonal to the extending direction of the connecting protrusion is smaller than the area of the second portion in the cross section orthogonal to the extending direction of the connecting protrusion,
The area of the said 1st connection part along a said 1st side wall is a pneumatic tire larger than the area of the said 1st part in the cross section orthogonal to the extension direction of the said connection protrusion.

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