JP2012040769A - Tire molding die - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire molding die to manufacture a pneumatic tire wherein work to take out the tire from a die is not complicated, original performance of the projections is spoiled by suppressing the projections after vulcanizing from becoming non-vulcanized, in the pneumatic tire which has projections to generate turbulent flow.SOLUTION: In the tire molding die which has a side mold for printing a sidewall of a green tire which is the tire before vulcanizing, the side mold includes: a surface forming part which forms a surface of the sidewall of the tire; and a first recess which becomes depressed towards a tire width direction outside from a surface forming part. In the first bottom which is the bottom in the first recess, a second recess which becomes depressed towards outside the tire width direction from the first bottom is formed. In a cross-section in the direction which is orthogonal to the tire width direction and the tire circumferential direction, the area of the second bottom which is the bottom in the second recess is smaller than the area of the opening which opens to the first recess in the second recess.

Description

  The present invention relates to a tire molding die for manufacturing a pneumatic tire in which a protrusion for generating a turbulent flow is provided on at least a part of the surface of a side wheel portion.

  In general, an increase in tire temperature in a pneumatic tire promotes a change with time such as a change in material properties, and thus is a factor that decreases the durability of the tire. On the other hand, a pneumatic tire is proposed in which a protrusion that generates turbulent flow is provided on at least a part of the surface of the side wheel portion (see, for example, Patent Document 1). In this pneumatic tire, the air flow generated by the protrusions hits the surface of the sidewall portion, and the surface of the sidewall portion can be cooled.

  In order to form a projection for generating a turbulent flow on the surface of the sidewall portion (referred to as a turbulent flow generation projection), a mold having a recess at a predetermined position where the projection is formed is used. A rubber material for forming the protrusion and the sidewall portion flows into the concave portion of the mold and is vulcanized to form the protrusion on the sidewall portion.

JP 2009-029377 A

  By the way, in the pneumatic tire which provided the protrusion in the side wall part, the following became a problem. That is, at the time of manufacturing a pneumatic tire, an air pocket is easily formed in the concave portion of the mold for forming the projection, and a depression due to the air pocket may be formed on the surface of the projection after molding.

  On the other hand, there are a method of providing an air vent hole so-called vent hole in the concave portion of the mold, and a method of providing an air pocket recess in the bottom surface of the concave portion of the mold. However, if a vent hole is provided in the concave portion of the mold, spew (saddle-like rubber) remains on the surface of the protrusion. On the other hand, if the depression of the air pocket is provided in the concave portion of the mold, the length of the spew can be suppressed to an allowable range, but the unvulcanized portion becomes large in the projection after molding. Specifically, the surface of the rubber that has entered the hollow of the air pocket is in a state where it is in contact with the air instead of the mold, so that it cannot be sufficiently heated and pressurized in the vulcanization process. May be unvulcanized. As a result, in the projection after molding, a crack may occur from the unvulcanized portion, which may cause problems such as cracking of the rubber of the pneumatic tire.

  Furthermore, when the vulcanized tire is taken out from the mold, there has been a problem that unvulcanized rubber adheres to the mold and the operation becomes complicated.

  Therefore, the present invention provides a pneumatic tire having protrusions that generate turbulent flow, and by suppressing the protrusions after vulcanization from becoming unvulcanized, it is not complicated to take out the tire from the mold. An object of the present invention is to provide a tire molding die for manufacturing a pneumatic tire that does not impair the original performance of the protrusion.

  First, the first feature of the present invention is that a tire molding die (tyre) having side molds (lower side mold 31 and upper side mold 33) for molding a sidewall portion of a raw tire that is a tire before vulcanization. In the molding die 10), the side mold is a surface forming portion (sidewall forming surfaces 31a, 33a) that forms the surface of the sidewall portion of the tire, and the raw tire is installed in the tire molding die from the surface forming portion. The first recess (projection forming portions 310 and 330) that is recessed toward the outer side in the tire width direction in the posture is formed, and the first bottom (bottom 311) that is the bottom of the first recess is formed from the first bottom A second recess (air reservoir recess 312) that is recessed outward in the tire width direction is formed, and the tire is positioned in the tire width direction and in a posture in which the tire is mounted on a tire molding die. In the cross section in the direction perpendicular to the circumferential direction, the area of the second bottom portion, which is the bottom portion (bottom portion 312b) in the second recess portion, is larger than the area of the opening portion (opening portion 312a) opening in the first recess portion in the second recess portion. The gist is small.

  According to this, in the second recess, when the raw tire is installed in the tire molding die and pressed, the opening having a large area in the cross section in the direction perpendicular to the tire width direction and the tire circumferential direction is made of rubber. It is blocked. Further, in the second recess, the rubber can be prevented from entering the second recess at a portion having a smaller area than the opening (portion close to the bottom). Therefore, it is possible to reduce the area where the rubber and air are in contact with each other in the second recess. That is, since the rubber | gum of a raw tire has many parts which contact | connect directly with the metal mold | die for tire shaping | molding, it can suppress the part which is not vulcanized. Therefore, in the molded pneumatic tire, it is possible to suppress the cracking of the rubber caused by the unvulcanized portion of the turbulent flow generation projection and the cracking of the rubber of the pneumatic tire generated due to the crack. Can do. As a result, it is possible to manufacture a pneumatic tire that does not impair the original performance of the protrusion.

  The second feature of the present invention relates to the first feature, and is summarized in that a plurality of second recesses are formed.

  The third feature of the present invention relates to the first feature, and is summarized in that a volume per one second recess is 1% or more and 10% or less of the volume of the first recess.

A fourth feature of the present invention relates to the first feature, wherein a plurality of second recesses are formed, and the total volume of the plurality of second recesses is 5% or more and 40% or less of the volume of the first recesses. It is a summary.

  The fifth feature of the present invention is related to the first feature, and is summarized in that the second recess has a cone shape or a column shape.

  According to the features of the present invention, in a pneumatic tire having protrusions that generate turbulent flow, it is not complicated to take out the tire from the mold by suppressing the vulcanized protrusions from becoming unvulcanized. Further, it is possible to provide a tire molding die for manufacturing a pneumatic tire that does not impair the original performance of the protrusion.

FIG. 1 is a partial perspective view including cross sections of a pneumatic tire in a tire width direction and a tire radial direction. FIG. 2 is a cross-sectional view of the tire molding die 10 according to the embodiment of the present invention in the tire width direction. FIG. 3A is an enlarged partial perspective view showing the protrusion forming portion. FIG. 3B is an enlarged sectional view in the tire width direction showing the protrusion forming portion. FIG. 4A is a schematic diagram showing an initial state when a raw tire is placed in a tire molding die and is pressed. FIG. 4B is a schematic view showing a state after a raw tire is installed in a tire molding die and is pressed. FIGS. 5A and 5B are enlarged sectional views in the tire width direction showing the protrusion forming portion according to the modified example. FIG. 6 is an enlarged partial perspective view showing the protrusion forming portion according to the modified example. FIG. 7 is an enlarged partial perspective view showing the protrusion forming portion according to the modified example.

  An embodiment of a pneumatic tire according to the present invention will be described with reference to the drawings. Specifically, (1) the configuration of the pneumatic tire, (2) the configuration of the tire molding die, (3) the configuration of the side mold, (4) the configuration of the air reservoir recess, (5) the rubber at the time of pressurization The state, (6) action / effect, (7) modified example, (8) comparative evaluation, (9) 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, the part from which the relationship and ratio of a mutual dimension differ also in between drawings is contained.

  Further, in the description of the present embodiment, the tire width direction, the tire radial direction, and the tire circumferential direction are defined, but these are all directions in a posture in which the raw tire is mounted on the tire molding die according to the present embodiment. Is shown.

(1) Configuration of Pneumatic Tire First, the configuration of a pneumatic tire manufactured by the tire molding die according to the present embodiment will be described with reference to FIG. FIG. 1 is a partial perspective view including a cross section of the pneumatic tire 100 in the tire width direction and the tire radial direction. Since the pneumatic tire 100 has a line-symmetric configuration with respect to the tire equator line CL, only one side is shown in FIG.

  As shown in FIG. 1, the pneumatic tire 100 includes a pair of bead portions 110 including at least a bead core 101, a bead filler 102, and a bead toe 103, and a carcass layer 111 folded back by the bead core 101.

  Inside the carcass layer 111, an inner liner 112 which is a highly airtight rubber layer corresponding to a tube is provided. Further, a turbulent flow generation projection 120 for generating turbulent flow is provided on the outer side in the tire width direction of the carcass layer 111, that is, on the tire surface 113 a in the sidewall portion 113. As an example, the length of the turbulent flow generation projection 120 in the tire circumferential direction (the width of the turbulent flow generation projection 120 in the tire axial view) is 5 mm, and the length of the turbulent flow generation projection 120 in the tire width direction is 5 mm. The height (height from the sidewall portion 113) is 20 mm. In this embodiment, in FIG. 1, three turbulent flow generation projections 120 are provided, but the present invention is not limited to this, and the number of turbulent flow generation projections 120 is determined depending on the type of tire and application. It can be set appropriately depending on the situation.

  A tread portion 130 in contact with the road surface is provided on the outer side of the carcass layer 111 in the tire radial direction. In addition, a plurality of belt layers 150 that reinforce the tread portion 130 are provided between the carcass layer 111 and the tread portion 130. Although not shown, a well-known tread pattern may be formed on the tire surface 130a of the tread portion 130.

(2) Configuration of Tire Molding Mold Next, a tire molding mold 10 according to the present embodiment will be described with reference to the drawings. FIG. 2 is a sectional view in the tire width direction of the tire molding die 10 in a state in which the sector mold 30, the lower side mold 31, and the upper side mold 33 are combined with each other.

  The unvulcanized tire TR is accommodated in a space (referred to as a vulcanization space) formed between the bladder 20, the sector mold 30, the lower side mold 33, and the upper side mold 31. The tire TR is a general tire including a bead portion, a carcass layer, and a belt layer (not shown). The tire TR has a tread portion TR1 (corresponding to the tread portion 130 in FIG. 1) and sidewall portions TR2 and TR3 (corresponding to the sidewall portion 113 in FIG. 1). Projections TR4 (corresponding to the turbulent flow generation protrusions 120) are formed on the sidewall portions TR2 and TR3.

  The sector mold 30 has a tread pattern forming surface 30a on which irregularities for forming a tread pattern are formed, and an inclined surface 30b. In the cross section in the tire width direction, the sector mold 30 has a lower end portion that is longer than an upper end portion.

  The outer ring 34 has an inclined surface 34a that contacts the inclined surface 30b. In the cross section in the tire width direction of the outer ring 34, the length of the upper end is longer than the length of the lower end.

  Accordingly, when the outer ring 34 is further lowered in the downward direction of the arrow V from the state in which the inclined surface 34a of the outer ring 34 is in contact with the inclined surface 30b of the sector mold 30, the inclined surface 34a of the outer ring 34 and the sector mold 30 inclined surfaces 30b slide.

  At this time, a force acts in a direction in which the sector mold 30, the lower side mold 31, and the upper side mold 33 are in close contact with each other (that is, a direction from the outside of the tire toward the center along the tire radial direction). Thereby, the sector mold 30, the lower side mold 31, and the upper side mold 33 are firmly adhered to each other to form a vulcanization space. The sector mold 30, the lower side mold 31, and the upper side mold 33 can be moved in and out of the tire radial direction by a moving mechanism (not shown). Further, during vulcanization, the heated and pressurized fluid R is blown into the bladder 21, so that the bladder 21 expands inside the tire TR. The tire TR is molded into the sector mold 30, the lower side mold 31, and the upper side mold 33 by the expanded bladder 21.

(3) Configuration of Side Mold Next, the configuration of the side mold will be described with reference to the drawings. FIG. 3A is a partial perspective view showing the protrusion forming portion 310 of the lower side mold 31 in an enlarged manner. FIG. 3B is an enlarged sectional view in the tire width direction showing the protrusion forming portion 310 of the lower side mold 31. For the sake of explanation, the raw tire is not shown in FIG. The lower side mold 31 includes a sidewall forming surface 31a for shaping the sidewall portion TR2 of the tire TR and a protrusion forming portion for forming the protrusion TR4. The protrusion formation part 310 is depressed toward the outer side in the tire width direction from the sidewall formation surface 31a. Similarly, the upper side mold 33 includes a sidewall forming surface 33a and a protrusion forming portion 330. The side wall forming surfaces 31a and 33a constitute a surface forming portion. The protrusion forming portions 310 and 330 constitute a first recess.

  Since the lower side mold 31 and the upper side mold 33 have the same structure, the lower side mold 31 will be described below, and details of the upper side mold 33 will be omitted.

  The protrusion forming portion 310 is recessed outward in the tire width direction from the sidewall forming surface 31a, and an air pocket recess further recessed from the bottom 311 toward the outer side in the tire width direction is formed on the bottom 311 of the protrusion forming portion 310. 312 is formed. The bottom part 311 of the projection forming part 310 constitutes a first bottom part. The air reservoir recess 312 constitutes a second recess.

(4) Configuration of Air Reservoir Recess Next, the configuration of the air reservoir recess will be described with reference to the drawings. As shown in FIGS. 3A and 3B, the air reservoir recess 312 has an area of the bottom 312 b of the air reservoir recess in the cross section in a direction perpendicular to the tire width direction and the tire circumferential direction. It is configured to be smaller than the area of the opening 312 a that opens to the bottom 311. That is, the air reservoir recess 312 has a shape that tapers from the opening 312a toward the bottom 312b. In the cross section in the direction orthogonal to the tire width direction and the tire circumferential direction, the area of the bottom 312b is formed to be 90% or less with respect to the area of the opening 312a.

  Further, the volume of the air reservoir recess 312 is smaller than the volume of the protrusion forming portion 310. The volume of one air reservoir recess 312 is formed to be 1% or more and 10% or less of the volume of the protrusion forming portion 310.

  Further, as shown in FIGS. 3A and 3B, in the present embodiment, two air reservoir recesses 312 are formed with respect to one protrusion forming portion 310. The total volume of the two air reservoir recesses 312 is formed to be 5% or more and 40% or less with respect to the volume of the protrusion forming portion 310.

(5) State of rubber during pressurization Next, with reference to the drawings, the state of rubber when a raw tire is placed in the tire molding die 10 according to the present embodiment and pressed will be described. FIG. 4A is a schematic diagram showing an initial state when a raw tire is placed in a tire molding die and is pressed. FIG. 4B is a schematic view showing a state after a raw tire is installed in a tire molding die and is pressed.

  As shown in FIG. 4A, as the bladder 21 expands, a part of the sidewall rubber of the raw tire TR enters the protrusion forming part 310. When the rubber of the raw tire TR enters the protrusion forming part 310, the air in the protrusion forming part 310 is trapped in the air reservoir recess 312 (arrow shown in FIG. 4A).

  Further, a part of the rubber of the raw tire TR that has entered the protrusion forming portion 310 enters the air reservoir recess 312 as shown in FIG. Here, since the volume of the air reservoir recess 312 is smaller than the volume of the protrusion forming portion 310, the air is compressed inside the air reservoir recess 312 by the rubber. For this reason, the rubber that has entered the air reservoir recess 312 remains when the internal pressure of the air compressed in the air reservoir recess 312 and the pressing force of the rubber are substantially balanced. FIG. 4B shows an example of the state of the raw tire TR when the internal pressure of the air compressed in the air reservoir recess 312 and the pressing force of the rubber are substantially balanced.

  Note that the amount of rubber entering the inside of the air reservoir recess 312 is adjusted by appropriately determining the ratio of the volume of the air reservoir recess 312 to the volume of the protrusion forming portion 310 without being limited to the example shown in FIG. can do.

(6) Actions / Effects Next, actions and effects of the tire molding die 10 according to the present embodiment will be described.

  In the present embodiment, the tire molding die 10 includes a sidewall forming surface 31a that forms the surface of the sidewall portion of the tire, and a projection forming portion 310 that is recessed outward from the sidewall forming surface 31a in the tire width direction. The bottom portion 311 that is the bottom portion of the projection forming portion 310 is formed with an air pocket recess 312 that is recessed from the bottom portion 311 toward the outer side in the tire width direction, and is orthogonal to the tire width direction and the tire circumferential direction. In the cross section, the area of the bottom 312b in the air reservoir recess 312 is configured to be smaller than the area of the opening 312a.

  According to this, the air reservoir recess 312 has a shape that tapers from the opening 312a toward the bottom 312b. For this reason, in the vulcanization step, the opening 312a having a large area in the cross section of the air reservoir recess 312 in the tire width direction and the direction orthogonal to the tire circumferential direction is blocked by the rubber and part of the rubber of the raw tire TR. Enters the air reservoir recess 312. Further, the rubber that has entered the air reservoir recess 312 stays in a portion having a smaller area than the opening 312a (portion close to the bottom 312b). Therefore, it is possible to reduce the area where the rubber and the air are in contact with each other in the air reservoir recess 312. That is, since the rubber of the raw tire TR has a large number of portions that are in direct contact with the tire molding die, the portion that is not vulcanized can be suppressed. Therefore, in the molded pneumatic tire, it is possible to suppress the cracking of the rubber caused by the unvulcanized portion of the turbulent flow generation projection and the cracking of the rubber of the pneumatic tire generated due to the crack. Can do. As a result, it is possible to manufacture a pneumatic tire that does not impair the original performance of the protrusion.

  In the present embodiment, a plurality of air reservoir recesses 312 are formed. According to this, the shape of the turbulent flow generation projection can be stabilized. Specifically, by forming a plurality of air reservoir recesses 312, the volume per one of the air reservoir recesses 312 can be reduced. As a result, it is possible to reduce the area in which the rubber and air of the raw tire TR are in contact with each other in the air reservoir recess 312 and suppress the unvulcanized portion of the turbulent flow generation projection in the molded pneumatic tire. can do. Here, if the shape of the turbulent flow generation projection, such as its height and edge, is not properly formed, the effect of suppressing the temperature rise of the pneumatic tire will be reduced. The mold 10 is very effective.

  In the present embodiment, the volume of the air reservoir recess 312 is 1% or more and 10% or less of the volume of the protrusion forming portion 310. If the volume of the air reservoir recess 312 is less than 1%, the capacity is insufficient, and the air driven into the air reservoir recess 312 may not be contained in the air reservoir recess 312. In this case, a depression is formed on the surface of the turbulent flow generation projection 120 after molding. On the other hand, if the volume of the air reservoir recess 312 exceeds 10%, the amount of rubber entering the air reservoir recess 312 becomes too large, thereby causing a protrusion (spew) due to the air reservoir recess 312 on the surface of the turbulent flow generation projection 120. Will be formed.

  In the present embodiment, a plurality of air reservoir recesses 312 are formed, and the total volume of the plurality of air reservoir recesses 312 is not less than 5% and not more than 40% of the volume of the protrusion forming portion 310. If the total volume of the plurality of air reservoir recesses 312 is less than 5%, the capacity is insufficient, and the air driven into the air reservoir recesses 312 may not be stored in the air reservoir recesses 312. In this case, a depression (bear) is formed on the surface of the turbulent flow generation projection 120 after molding. On the other hand, if the total volume of the plurality of air reservoir recesses 312 exceeds 40%, the amount of rubber entering the air reservoir recesses 312 becomes too large, so that the protrusion of the air reservoir recesses 312 on the surface of the turbulent flow generation projections 312. A part (spy) will be formed.

  In addition, according to the tire molding die according to the present embodiment, no air vent hole, so-called vent hole is provided, and therefore, in the pneumatic tire after molding, it is necessary to cut the surface of the turbulent flow generation projection. There will be no spew left. Further, no depression (bear) is formed on the surface of the turbulent flow generation projection 120 formed on the molded pneumatic tire. Therefore, it is possible to manufacture a pneumatic tire that does not impair the original performance of the protrusion without causing air accumulation or spew.

(7) Modification Example Next, a modification example of the tire molding die 10 according to the present embodiment will be described with reference to FIGS. 5 (a), 5 (b), 6, and 7.

  The tire molding die 10 according to the present embodiment can be modified as follows.

  In the tire manufacturing mold according to the present embodiment, the number of air reservoir recesses 312 formed in the protrusion forming part 310 for forming the turbulent flow generation protrusion 120 of the sidewall part is not limited to two, Three may be sufficient as shown to Fig.5 (a). Moreover, as shown in FIG.5 (b), four may be sufficient. The number of air reservoir recesses 312 formed in the protrusion forming portion 310 for forming the turbulent flow generation protrusion 120 in the sidewall portion can be appropriately changed according to the shape of the tire and the application.

  Moreover, the shape of the air pocket recessed part 312 formed in the metal mold | die 10 for tire molding which concerns on this embodiment can be changed as follows. FIGS. 6 and 7 are views when the projection forming part 310 and the air reservoir recess 312 formed in the tire molding die 10 are viewed through the tire molding die 10 for the sake of explanation. It is.

  As shown in FIG. 6A, the air reservoir recess 312 may be formed with a cylindrical recess that is further recessed outward from the bottom 312 a of the air reservoir recess 312 in the tire width direction. As shown in FIG.6 (b), it may be formed so that the cylindrical recessed part with a small volume may be connected as it goes to a tire width direction outer side. As shown in FIG.6 (c), you may form so that the cylindrical recessed part with two small volumes may be connected from the recessed part of a cylinder. Moreover, as shown to Fig.7 (a), (b), a cone shape or a quadrangular pyramid shape may be sufficient. As shown in FIGS. 7C and 7D, a cylindrical or rectangular parallelepiped recess whose volume decreases toward the outer side in the tire width direction may be connected.

(8) Comparative Evaluation A pneumatic tire having a turbulent flow generation protrusion manufactured using the tire molding die of the present embodiment and a turbulent flow generation protrusion manufactured using a conventional tire molding die. Comparison with pneumatic tires. Note that the tire molding die used for comparison has a projection forming portion and two air reservoir recesses at both ends of the projection forming portion. In Comparative Example 1 and Examples 1 to 5, the shape of the air reservoir recess is different, and the conditions are shown below.

  Comparative Example 1: The air reservoir recess has a cylindrical shape.

  Examples 1 and 2: It is the shape of the air pocket recessed part which concerns on embodiment, and is a substantially cone shape.

  Examples 3 and 4: As shown in FIG. 7 (c), the shape of the air reservoir according to the modified example is formed by stacking two types of cylinders having different volumes, and the protrusion forming portion A columnar shape with a large volume is provided on the near side.

As an evaluation method, a pneumatic tire was manufactured using a tire molding die in which these air pockets were formed, and the areas of unvulcanized rubber were compared on the surface of the turbulent flow generation projection. Further, the comparison results show that Comparative Example 1 is 100%, and the smaller the value, the less unvulcanized rubber. The evaluation results are shown in Table 1 below.

  As shown in Table 1, the pneumatic tire manufactured using the tire molding die according to Examples 1 to 4 is compared with the pneumatic tire manufactured using the tire molding die according to Comparative Example 1. It was proved that there was significantly less unvulcanized rubber on the surface of the turbulent flow generation projection.

(9) 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 and examples will be apparent to those skilled in the art. For example, the embodiment of the present invention can be modified as follows.

  In the tire molding die according to the embodiment, the case where the air reservoir recess 312 having the same shape is formed in the projection forming portion for forming the turbulent flow generation projection 120 in the sidewall portion has been described. However, an air reservoir recess 312 having a different shape may be formed for one protrusion forming portion 310.

  Further, the shape of the turbulent flow generation projection 120 is not limited to the rectangular shape shown in FIG. For example, the surface of the turbulent flow generation projection may be inclined or a curved surface. Moreover, the width | variety of a processus | protrusion may differ in an edge part and a center part.

  Further, the projection forming portion 312 formed on the tire molding die 10 is not limited to the concave portion for forming the turbulent flow generation projection 120. For example, the present invention can be applied to any part where it is difficult to trim the spew remaining in the molded product.

  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 10 ... Tire molding die, 30 ... Sector mold, 30a ... Tread pattern formation surface, 30b ... Inclined surface, 31 ... Lower side mold, 31a, 33a ... Side wall formation surface, 33 ... Upper side mold, 34 ... Outer Ring, 34a ... inclined surface, 100 ... tire, 101 ... bead core, 101 ... the bead core, 102 ... bead filler, 103 ... bead toe, 110 ... bead part, 111 ... carcass layer, 112 ... inner liner, 113 ... sidewall part, DESCRIPTION OF SYMBOLS 113 ... Tread part, 113a ... Tire surface, 120 ... Protrusion for turbulent flow generation, 130 ... Tread part, 150 ... Belt layer, 310 ... Protrusion formation part, 311 ... Bottom part, 312 ... Air reservoir recessed part, 312a ... Opening part, 312b ... bottom, 330 ... projection formation

Claims (5)

In a mold for molding a tire having a side mold that molds a sidewall portion of a raw tire that is a tire before vulcanization,
The side mold is
A surface forming portion for forming a surface of the sidewall portion of the tire;
A first recess recessed from the surface forming portion toward the outer side in the tire width direction in a posture in which the raw tire is mounted on the tire molding die;
The first bottom that is the bottom of the first recess is formed with a second recess that is recessed from the first bottom toward the outside in the tire width direction,
In the cross section in the direction perpendicular to the tire circumferential direction in the posture where the tire width direction and the raw tire are mounted on the tire molding die,
The area of the second bottom that is the bottom of the second recess is:
A mold for molding a tire, wherein the mold is smaller than an area of an opening opening in the first recess in the second recess. The second recess is
The tire mold according to claim 1, wherein a plurality of the molds are formed. The volume per one of the second recesses is
2. The mold for molding a tire according to claim 1, wherein the mold is 1% or more and 10% or less of a volume of the first recess. A plurality of the second recesses are formed,
2. The tire molding die according to claim 1, wherein the total volume of the plurality of second recesses is not less than 5% and not more than 40% of the volume of the first recesses. The second recess is
The tire mold according to claim 1, wherein the mold is a cone shape or a column shape.

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