JP2016101882A - Pneumatic tire and method for production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the adhesiveness of a side wall member to another tire constitution member disposed inside the side wall member in response to the thickness distribution of the side wall member in which an air discharge groove is formed.SOLUTION: A side wall member 21 of a pneumatic tire 1 comprises a sticking face 22 to a carcass ply 9. Further, an air discharge groove 26 is formed on the sticking face 22 of the side wall member 21 before vulcanization molding to extend in a tire radial direction in order to discharge outside air included between the sticking face and the carcass ply 9. A width of the air discharge groove 26 has a normal correlation to a thickness of the side wall member.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pneumatic tire and a method for manufacturing the same.

  The manufacturing process of a pneumatic tire includes a molding process and a vulcanization process. In the molding step, a plurality of tire constituent members such as a tread member, a sidewall member, a carcass ply, a bead, a bead filler, and a belt ply are bonded on a molding drum to mold a raw tire. In the vulcanization step, the raw tire is vulcanized and molded in a tire molding vulcanization mold, and a pneumatic tire as a product is obtained.

  Air accumulation is likely to occur between the tire constituent members bonded together in the molding process. If the green tire in which air pockets remain is subjected to the vulcanization process, it may cause a failure such as separation or a poor appearance. It is known that the air in the air pocket is discharged to the outside of the raw tire by performing stitching (rolling) on the bonded tire constituent members before the vulcanization process.

  Patent Documents 1 and 2 disclose that an air discharge groove is formed on the bonding surface of the sidewall member to the carcass ply in order to increase the efficiency of air discharge by stitching.

JP 2004-284165 A JP 2008-126649 A

  However, in the side wall member in which the air discharge groove is formed on the bonding surface to the carcass ply known in the related art including those disclosed in Patent Documents 1 and 2, the thickness distribution of the side wall member Sufficient studies have not been made to make the adhesion of the side wall member to the carcass ply uniform. Such non-uniform adhesion causes a failure such as separation.

  The present invention provides uniform adhesion of a sidewall member to another tire component member with respect to the thickness distribution of the sidewall member in which an air discharge groove is formed on a bonding surface to another tire component member positioned inside. The problem is to make it.

  The first invention is a pneumatic tire formed by vulcanizing a raw tire formed by bonding a plurality of tire constituent members including a sidewall member, wherein the sidewall member is adjacent to another tire. A bonding surface for a tire component member is provided, and air existing between the other tire component member is discharged to the bonding surface of the sidewall member before vulcanization molding to the outside during stitching. The pneumatic exhaust groove is formed to extend in the tire radial direction, and the width of the air exhaust groove has a positive correlation with the thickness of the sidewall member.

  The pressing force that the surface of the side wall member is pressed against other adjacent tire components by stitching is relative to the part where the thickness of the side wall member is thin (the part with a small amount of rubber per unit volume). However, it is relatively small in a portion where the sidewall member is thick (a portion where the amount of rubber per unit volume is large). On the other hand, the width of the air discharge groove has a positive correlation with the thickness of the sidewall member. Therefore, in the portion where the thickness of the sidewall member having a large pressing force is small, the width of the air discharge groove is narrow, and the contact area (for example, the contact area per unit area) with respect to other adjacent tire constituent members is relatively wide. Further, in the portion where the thickness of the sidewall member having a small pressing force is large, the width of the air discharge groove is wide, and the contact area with other adjacent tire constituent members is relatively small. In other words, by making the width of the air discharge groove have a positive correlation with the thickness of the sidewall member, the contact area can be widened at a portion where the pressing force is large, and conversely the contact area can be narrowed at a portion where the pressing force is small. As a result, the adhesiveness to other tire constituent members adjacent to the attachment surface of the sidewall member can be made uniform.

  The depth of the air discharge groove may have a positive correlation with the thickness of the sidewall member.

  The thicker portion of the sidewall member has a relatively larger amount of rubber per unit area than the thinner portion, and the pressing force against other tire constituent members adjacent to the pasting surface is relatively small. By making the depth of the air discharge groove positively correlate with the thickness of the sidewall member, and increasing the volume of the air discharge groove in the thick part of the sidewall member, Can reduce the amount of rubber. As a result, it is possible to increase the pressing force in the portion where the sidewall member is thick. As a result, the adhesion to other tire constituent members adjacent to the attachment surface of the sidewall member can be made more uniform.

  The cross-sectional shape of the air discharge groove may vary depending on the thickness of the sidewall member.

  The sidewall member is provided on a first portion having a first thickness provided on the center side in the width direction, and on both sides in the width direction of the first portion, and extends in the width direction from the first portion side. A second portion whose thickness gradually decreases from the first thickness toward the portion, and the width of the air discharge groove extends from the end portion of the second portion in the width direction of the first portion. You may increase toward the center side.

  In the second invention, a plurality of tire constituent members including a sidewall member are bonded to form a raw tire, and the sidewall member extends in a tire radial direction on a bonding surface with respect to another adjacent tire constituent member. An air discharge groove is formed, and the width of the air discharge groove has a positive correlation with the thickness of the sidewall member, and the pasting of the sidewall member is performed while rotating the raw tire. Pressing a stitching tool against the surface opposite to the surface, exhausting the air interposed between the sidewall member and the other tire constituent member to the outside of the raw tire through the air exhaust groove, Provided is a method for producing a pneumatic tire in which a raw tire is placed in a tire vulcanization mold and vulcanized.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesiveness with respect to another tire structural member arrange | positioned inside the side wall member with respect to the thickness distribution of the side wall member in which the air exhaust groove was formed can be made uniform.

The half sectional view of the meridian direction of the pneumatic tire concerning a 1st embodiment of the present invention. The typical fragmentary perspective view of the sidewall member which concerns on 1st Embodiment of this invention. Sectional drawing in the EE line | wire of FIG. Sectional drawing in the AA line of FIG. 2, a BB line, and CC line. The typical fragmentary perspective view of the sidewall member which concerns on the modification of 1st Embodiment. Sectional drawing similar to FIG. 3 of the side wall member which concerns on the modification of 1st Embodiment. The typical fragmentary perspective view of the sidewall member which concerns on 2nd Embodiment of this invention. Sectional drawing in the EE line | wire of FIG. Sectional drawing in the AA line of FIG. 7, a BB line, and CC line. The typical fragmentary perspective view of the sidewall member which concerns on 3rd Embodiment of this invention. Sectional drawing in the AA line of FIG. 10, a BB line, CC line, and DD line. The typical fragmentary perspective view of the sidewall member which concerns on 4th Embodiment of this invention. Sectional drawing in the AA line of FIG. 11, a BB line, CC line, and DD line.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In addition, the following description is only illustrations essentially and does not intend restrict | limiting this invention, its application thing, or its use. Further, the drawings are schematic, and the ratio of each dimension may be different from the actual one.

(First embodiment)
A pneumatic tire (hereinafter simply referred to as a tire) 1 according to the first embodiment of the present invention shown in FIG. 1 includes a tread portion 2, a pair of side portions 3, and a pair of bead portions 4. Side portions 3 extend in the tire radial direction from both ends of the tread portion 2 in the tire width direction via shoulder portions. A bead portion 4 is provided on the inner end portion 3a side of the side portion 3 in the tire radial direction. The bead unit 4 includes a bead core 5, a bead filler 6, and a chafer 7.

  A carcass 8 is provided between the pair of bead portions 4. In the present embodiment, the carcass 8 includes one carcass ply 9. An inner liner 10 is provided on the innermost peripheral surface of the tire 1. Further, in the tread portion 2, a belt 11 is provided on the outer side in the tire radial direction of the carcass 8. In the present embodiment, the belt 11 includes two belt plies 12 and 13 and a reinforcing ply 14.

  In the present embodiment, the inner surface 3a in the tire radial direction of the side portion 3 is disposed adjacent to the outer side in the tire radial direction of the chafer 7 in the vicinity of the inner end portion 3a in the tire radial direction. The ply 9 is disposed adjacent to the outer side in the tire radial direction.

  The manufacturing process of the tire 1 includes a molding process and a vulcanization process.

  In the molding process, the tire component, that is, the inner liner 10, the chafer 7, the carcass ply 9, the bead core 5, the bead filler 6, and the side wall member 21 serving as the side portion 3 (to be described in detail later with reference to FIG. 2 and subsequent drawings). The belt plies 12 and 13, the reinforcing ply 14, and the tread member to be the tread portion 2 are bonded together on a molding drum (not shown) and shaped into a toroid. In other words, these tire components are assembled on a molding drum to produce an unvulcanized green tire.

  Stitching (rolling) is performed on the raw tire before the vulcanization process in order to discharge air interposed between the tire constituent members to the outside. FIG. 1 conceptually shows the stitching tool 15. In the stitching, the stitching tool 15 is pressed against the surface of the raw tire while rotating the raw tire in the tire circumferential direction. Further, the stitching tool 15 is moved from the bead part 4 side toward the end part in the tire width direction of the tread part 2 while maintaining the state pressed against the surface of the raw tire. When attention is paid to the sidewall member 21 (side portion 3) during stitching, the profile surface 23 (the outer surface 3c of the side portion 3 in the tire radial direction) of the sidewall member 21 is the inner end portion 24 (side portion in the tire radial direction). 3 from the tire radial direction inner end 24) side, that is, from the bead portion 4 side, to the tire radial direction outer end 25 (side portion 3 outer end portion 3d in the tire radial direction) side, that is, from the tread portion 2 side. The stitching tool 15 is pressed in order. In other words, the pressing position of the sidewall member 21 by the stitching tool 15 is from the inner end 24 in the tire radial direction (end on the bead portion 4 side) to the outer end 25 in the tire radial direction (on the tread portion 2 side). Move toward the (end) side. By the stitching tool 15, the other tire constituent members adjacent to the inner side in the tire radial direction, that is, the chafer 7 and the carcass ply 9, are attached to the bonding surface 22 of the sidewall member 21 (the inner surface 3 b in the tire radial direction of the side portion 3). Pressed against.

  The raw tire after stitching is subjected to a vulcanization process. In the vulcanization process, the green tire is placed in a tire vulcanization mold (not shown) and heated and pressurized. The tire 1 as a product is obtained by this vulcanization molding.

  The sidewall member 21 will be described with reference to FIGS.

  The side wall member 21 is an elongated belt-like rubber member having a substantially constant width as a whole, and has a longitudinal direction (corresponding to the tire circumferential direction of the side portion 3) in the direction indicated by the symbol L in FIG. It has the width direction (equivalent to the tire radial direction of the side part 3) shown with the code | symbol S in a figure. The side wall member 21 has a flat affixing surface 22 (corresponding to the inner surface 3b in the tire radial direction of the side part 3) on one side, and a profile surface 23 (a side part) on the opposite side of the affixing surface 22 3 corresponding to the outer surface 3c in the tire radial direction. The inner end 24 that is one end in the width direction S of the sidewall member 21 corresponds to the inner end 3 a of the side 3 in the tire radial direction. Further, the outer end 25 which is the other end in the width direction S of the sidewall member 21 corresponds to the outer end 3d of the side 3 in the tire radial direction.

  A plurality of air discharge grooves 26 extending in the width direction (tire radial direction) S from the inner end 24 to the outer end 25 are spaced in the longitudinal direction (tire circumferential direction) L on the attachment surface 22 of the sidewall member 21. A plurality are provided with a gap. If the bottom walls of these air discharge grooves 26 are used as a reference, a portion between a pair of adjacent air discharge grooves 26 can be regarded as a protrusion.

  The individual air discharge grooves 26 are provided over the entire width direction S of the attaching surface 22. That is, the air discharge groove 26 is continuously provided from the inner end 24 to the outer end 25 of the sidewall member 21 without interruption.

  The profile surface 23 includes a first profile portion 23 a that is substantially parallel to the pasting surface 22 at the center in the width direction S. The profile surface 23 includes a pair of second profile portions 23b that are flat inclined surfaces extending from both ends of the first profile portion 23a in the width direction S to the inner end portion 24 and the outer end portion 25. These second profile parts 23 b have an inclination approaching the attaching surface 22 toward the inner end part 24 and the outer end part 25. Of the sidewall member 21, a portion including the first profile portion 23a constitutes a first portion 21a having a substantially constant thickness TH, and two portions including the second profile portion 23b have an inner end having a thickness TH. A second portion 21 b that gradually decreases toward the portion 24 and the outer end portion 25 is formed. The profile surface 23 of this embodiment is only an example, and the shape of the profile surface 23 may be different from that of this embodiment.

  The profile surface 23 of the side wall member 21 at the time of stitching is in order from the inner end portion 24 (end portion on the bead portion 4 side) to the outer end portion 25 (end portion on the tread portion 2 side) in order. The tire component, that is, the chafer 7 and the carcass ply 9 is pressed by the stitching tool 15. In other words, the pressing position by the stitching tool 15 moves from the inner end 24 in the tire radial direction of the sidewall member 21 toward the outer end 25. Air interposed between the sidewall member 21 and the chafer 7 or the carcass ply 9 is captured by the air discharge groove 26 by stitching, and is discharged from the outer end 25 side of the air discharge groove 26 to the outside of the raw tire. The

  Referring to FIGS. 2 and 4, the width W of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the center in the width direction S and from the center toward the outer end 25. It is gradually decreasing. By changing the width W in this way, the width W of the air discharge groove 26 in the first portion 21a of the sidewall member 21 having a constant thickness TH (relatively thick thickness TH) TH is relatively larger than the width W of the second portion 21b (thickness TH is equal to or less than the thickness of the first portion 21a) in which TH gradually decreases toward the inner end 24 and the outer end 25. That is, the width W of the air discharge groove 26 has a positive correlation with the thickness TH of the sidewall member 21. In other words, the width W of the air discharge groove 26 is wide at the portion where the thickness TH is thick, and the width W of the air discharge groove 26 is narrow at the portion where the thickness TH is thin.

  The thickness TH of the side wall member 21 is thin as the pressing force pressed against the other tire constituent members adjacent to the bonding surface 22 of the side wall member 21 by the stitching tool 15, that is, the chafer 7 or the carcass ply 9. It is relatively large in the part (part where the amount of rubber per unit volume is small). In the present embodiment, the pressing force of the attaching surface 22 at the second portion 21b (in particular, near the inner end 24 and the outer end 25) where the thickness TH gradually decreases toward the inner end 24 and the outer end 25. Is relatively large. On the other hand, in the portion where the thickness TH of the sidewall member 21 is thick (the portion where the amount of rubber per unit volume is large), the affixing surface 22 of the sidewall member 21 with respect to the chafer 7 and the carcass ply 9 by the stitching tool 15. The pressing force pressed is relatively small. In the present embodiment, the pressing force of the attaching surface 22 in the first portion 21a having a constant thickness TH is relatively small.

  As described above, the pressing force of the attachment surface 22 of the sidewall member 21 during stitching decreases as the thickness TH of the sidewall member 21 increases, and conversely increases as the thickness TH decreases. On the other hand, the width W of the air discharge groove 26 has a positive correlation with the thickness TH of the sidewall member 21 as described above. Accordingly, the width of the air discharge groove 26 is a portion where the thickness TH of the sidewall member 21 having a large pressing force is thin (in the present embodiment, particularly in the vicinity of the inner end 24 and the outer end 25 of the second portion 21b). W is narrow, and the contact area (for example, the contact area per unit area) of the attaching surface 22 with respect to the chafer 7 and the carcass ply 9 is relatively wide. On the other hand, in the portion where the thickness TH of the sidewall member 21 with a small pressing force (the first portion 21a in this embodiment) is large, the width W of the air discharge groove 26 is wide, and the contact area with respect to the chafer 7 and the carcass ply 9 is Relatively narrow. That is, by making the width W of the air discharge groove 26 have a positive correlation with the thickness TH of the sidewall member 21, the contact area is widened in the portion where the pressing force is large, and conversely in the portion where the pressing force is small. Can be narrowed. As a result, the adhesiveness of the affixing surface 22 to the chafer 7 and the carcass ply 9 can be made uniform with respect to the distribution of the thickness TH of the sidewall member 21.

  As shown most clearly in FIG. 3, the depth D of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the center in the width direction S, and from the center to the outer end 25. It is gradually decreasing. By changing the depth D, the depth D of the air discharge groove 26 in the first portion 21a of the sidewall member 21 having a constant thickness TH is set such that the thickness TH is equal to the inner end 24 or the outer side. It becomes relatively deeper than the depth D of the second portion 21 b that gradually decreases toward the end portion 25. That is, the depth D of the air discharge groove 26 has a positive correlation with the thickness TH of the sidewall member 21. In other words, the depth D of the air discharge groove 26 is deep in the portion where the thickness TH is thick, and the depth D of the air discharge groove 26 is shallow in the portion where the thickness TH is thin.

  A portion of the sidewall member 21 having a large thickness TH (the first portion 21a in the present embodiment) is a portion having a small thickness TH (in the second embodiment, the second portion 21b, in particular, the inner end portion 24 and the outer end portion). The amount of rubber per unit area of the attaching surface 22 is relatively large and the pressing force of the attaching surface 22 against the chafer 7 and the carcass ply 9 is relatively small. By making the depth D of the air discharge groove 26 have a positive correlation with the thickness TH of the sidewall member 21, the volume of the air discharge groove 26 in the portion where the thickness TH of the sidewall member 21 is thick is increased. The amount of rubber per unit area of the attaching surface 22 in this portion can be reduced. As a result, it is possible to increase the pressing force at the portion where the thickness TH of the sidewall member 21 is thick. Therefore, by making the depth D of the air discharge groove 26 have a positive correlation with the thickness of the sidewall member 21, the chafer 7 on the attaching surface 22 and the distribution of the thickness TH of the sidewall member 21 The adhesion to the carcass ply 9 can be further uniformized.

  As shown most clearly in FIG. 4, the shape of the cross section (hereinafter simply referred to as the cross-sectional shape) of each air discharge groove 26 perpendicular to the direction in which it extends (the width direction S of the side wall member 21) is air. The entire length of the discharge groove 26 is semicircular. In other words, the cross-sectional shape of the air discharge groove 26 is constant from the inner end 24 to the outer end 25 of the sidewall member 21. In the present embodiment and the second to fourth embodiments described later, the cross-sectional shape of the air discharge groove 26 is not particularly limited. However, the width W needs to increase from the bottom wall of the air discharge groove 26 toward the opening, and the width W needs to be maximum at the opening.

  5 and 6 show a modification of the first embodiment. The modification of FIG. 5 differs from the first embodiment only in the manner in which the width W of the air discharge groove 26 changes. Specifically, the width W of the air discharge groove 26 in the first portion 21 a of the sidewall member 21 is constant, and the width of the air discharge groove 26 toward the inner end portion 24 and the outer end portion 25 in the second portion 21 b. W gradually decreases. The modification of FIG. 6 differs from the first embodiment only in the manner in which the depth D of the air discharge groove 26 changes. Specifically, the depth D of the air discharge groove 26 in the first portion 21 a of the sidewall member 21 is constant, and in the second portion 21 b, the air discharge groove 26 is directed toward the inner end portion 24 and the outer end portion 25. The depth D is gradually reduced.

  Hereinafter, second to fourth embodiments of the present invention will be described. In these embodiments, points not particularly mentioned are the same as those in the first embodiment. In the drawings relating to these embodiments, the same or similar elements as those in the first embodiment are denoted by the same or similar reference numerals.

(Second Embodiment)
In the second embodiment of the present invention shown in FIGS. 7 to 9, the width W of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the central portion in the width direction S, and from the central portion. It gradually decreases toward the outer end 25 and has a positive correlation with the thickness TH of the sidewall member 21. By making the width W of the air discharge groove 26 have a positive correlation with the thickness TH of the sidewall member 21, the contact area of the attaching surface 22 with respect to the chafer 7 or the carcass ply 9 is widened in a portion where the pressing force is large. On the contrary, the contact area of the affixing surface 22 with respect to the chafer 7 and the carcass ply 9 can be narrowed at the portion where the pressing force is small. As a result, the adhesiveness of the affixing surface 22 to the chafer 7 and the carcass ply 9 can be made uniform with respect to the distribution of the thickness TH of the sidewall member 21.

  As shown most clearly in FIG. 8, the depth D of each air discharge groove 26 is constant from the inner end 24 to the outer end 25 of the sidewall member 21. In other words, the depth D of the air discharge groove 26 is the same in the first portion 21 a and the second portion 21 b of the sidewall member 21.

  As shown most clearly in FIG. 9, the sectional shape of each air discharge groove 26 is all semi-elliptical in the entire length direction of the air discharge groove 26. In other words, the cross-sectional shape of the air discharge groove 26 is constant from the inner end 24 to the outer end 25 of the sidewall member 21.

(Third embodiment)
In the third embodiment of the present invention shown in FIGS. 10 and 11, the width W of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the center in the width direction S, and from the center. It gradually decreases toward the outer end 25 and has a positive correlation with the thickness TH of the sidewall member 21. By setting the width W of the air discharge groove 26, the adhesiveness of the attachment surface 22 to the chafer 7 and the carcass ply 9 can be made uniform with respect to the distribution of the thickness TH of the sidewall member 21.

  As shown in FIG. 11, in this embodiment, the depth D of each air discharge groove 26 is constant from the inner end 24 to the outer end 25 of the sidewall member 21.

  As shown in FIG. 11, the cross-sectional shape of the air discharge groove 26 changes continuously. Specifically, the cross-sectional shape of the air discharge groove 26 is substantially V-shaped at the inner end 24 side and the outer end 25 side, and is semi-elliptical at the center in the width direction of the first portion 21a. The region between the center in the width direction of the portion 21a and the inner end 24 and the outer end 25 has an intermediate shape between a V shape and a semi-elliptical shape.

(Fourth embodiment)
In the fourth embodiment of the present invention shown in FIGS. 12 and 13, the width W of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the center in the width direction S, and from the center. It gradually decreases toward the outer end 25 and has a positive correlation with the thickness TH of the sidewall member 21. By setting the width W of the air discharge groove 26, the adhesiveness of the attachment surface 22 to the chafer 7 and the carcass ply 9 can be made uniform with respect to the distribution of the thickness TH of the sidewall member 21.

  As shown in FIG. 13, the depth D of each air discharge groove 26 gradually increases from the inner end 24 of the sidewall member 21 to the center in the width direction S and gradually decreases from the center toward the outer end 25. doing. By setting the depth D of the air discharge groove 26, the adhesiveness of the attachment surface 22 to the chafer 7 and the carcass ply 9 can be made more uniform with respect to the distribution of the thickness TH of the sidewall member 21.

  As shown in FIG. 13, the cross-sectional shape of each air discharge groove 26 continuously changes. Specifically, the cross-sectional shape of the air discharge groove 26 is substantially V-shaped at the inner end 24 side and the outer end 25 side, and is semi-elliptical at the center in the width direction of the first portion 21a. The region between the center in the width direction of the portion 21a and the inner end 24 and the outer end 25 has an intermediate shape between a V shape and a semi-elliptical shape.

DESCRIPTION OF SYMBOLS 1 Tire 2 Tread part 3 Side part 3a Inner edge part 3b Inner surface 3c Outer surface 3d Outer edge part 4 Bead part 5 Bead core 6 Bead filler 7 Chafer 8 Carcass 9 Carcass ply 10 Inner liner 11 Belt 12, 13 Belt ply 14 Reinforcement ply 15 Stitching tool 21 Side wall member 21a 1st part 21b 2nd part 22 Pasting surface 23 Profile surface 23a 1st profile part 23b 2nd profile part 24 Inner edge part 25 Outer edge part 26 Air exhaust groove

Claims (5)

A raw tire formed by bonding a plurality of tire constituent members including a sidewall member is a pneumatic tire formed by vulcanization molding,
The sidewall member includes a bonding surface for another adjacent tire constituent member,
On the bonding surface of the sidewall member before the vulcanization molding, an air discharge groove for discharging the air interposed between the other tire constituent members at the time of stitching to the outside is provided in the tire radial direction. Formed to extend,
The pneumatic tire has a positive correlation between the width of the air discharge groove and the thickness of the sidewall member. The pneumatic tire according to claim 1, wherein the depth of the air exhaust groove has a positive correlation with the thickness of the sidewall member. The pneumatic tire according to claim 1 or 2, wherein a cross-sectional shape of the air discharge groove is changed according to a thickness of the sidewall member. The sidewall member is
A first portion having a first thickness provided on the center side in the width direction;
A second portion that is provided on both sides in the width direction of the first portion and has a thickness that gradually decreases from the first thickness toward the end in the width direction from the first portion side;
The width | variety of the said air exhaust groove is increasing toward the center side of the width direction of the said 1st part from the said edge part of the said 2nd part, The any one of Claims 1-3. Pneumatic tire. A plurality of tire constituent members including a sidewall member are bonded to form a raw tire, and an air discharge groove extending in the tire radial direction is formed on the side wall member on a bonding surface with respect to another adjacent tire constituent member. The width of the air discharge groove has a positive correlation with the thickness of the sidewall member,
While rotating the raw tire, a stitching tool is pressed against the surface opposite to the affixing surface of the sidewall member, and the air interposed between the sidewall member and the other tire constituent member, Discharged to the outside of the raw tire through the air discharge groove,
A method for producing a pneumatic tire, wherein the green tire is placed in a tire vulcanization mold and vulcanized.

Images