JP2016093935A - Pneumatic tire and method for production of pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of efficiently discharging air including in plural tire constituents in a green tire formed by sticking the plural tire constituents.SOLUTION: In a pneumatic tire produced by vulcanization-molding a green tire 10 formed by sticking plural tire constituents, the green tire is characterized by including: a tread member 20 which has a tread side air discharge groove 23 for guiding outside the air included between the tread and a sidewall member 30 on at least the face 41 adjacent to the sidewall member 30; and the sidewall member 30 which is adjacent to the tread member 20 via the adjacent face 41 and has a sidewall side air discharge groove 33 crossing with the tread side air discharge groove 23 on at least the adjacent face 41.SELECTED DRAWING: Figure 2

Description

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

  In general, a pneumatic tire is an unvulcanized raw tire formed by bonding 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 on a molding drum. Manufactured by vulcanization molding in a tire molding vulcanization mold. The plurality of tire constituent members constituting the raw tire each have a predetermined thickness. For this reason, when the plurality of tire constituent members are bonded together, stepped portions are easily generated at the end portions of the respective members. Due to the portion, an air pocket is easily generated between the tire constituent members.

  Conventionally, air exhaust grooves are formed in each tire constituent member in order to eliminate air accumulation between the tire constituent members, and air is passed from the air reservoir through the air exhaust grooves by stitching (rolling). Extruding is done. For example, Patent Document 1 discloses forming an air discharge groove extending in a tire radial direction or a tire circumferential direction in a sidewall.

JP 2004-284165 A

  However, the air discharge groove of Patent Document 1 is merely disclosed to be formed so as to extend in the tire radial direction or the tire circumferential direction, and no special consideration has been given to the arrangement of the air discharge groove, and an improvement has been made. There was room for.

  An object of this invention is to provide the pneumatic tire which can discharge | emit efficiently the air interposed between several tire structural members in the state of a raw tire.

  The present invention is a pneumatic tire formed by vulcanization molding a raw tire formed by bonding a plurality of tire constituent members, and the plurality of tire constituent members in an unvulcanized state are A first tire constituent member provided with at least a first air exhaust groove for exhausting air intervening between other adjacent tire constituent members to the outside, at least on a surface adjacent to the other tire constituent member; A second tire constituent member that is adjacent to the first tire constituent member via an adjacent surface and includes a second air exhaust groove that intersects the first air exhaust groove at least on the adjacent surface. It is characterized by that.

  According to this configuration, the first air exhaust groove formed in the first tire constituent member and the second air exhaust groove formed in the second tire constituent member intersect at the adjacent surface. The air pushed out to one of the second air discharge grooves can be dispersed in both the first and second air discharge grooves via the intersection. As a result, the air discharge path can be increased and the amount of accumulated air can be increased, so that the air interposed between the plurality of tire constituent members in the raw tire can be efficiently discharged.

  It is preferable that at least one of the first air discharge groove and the second air discharge groove extends in an inclined direction inclined with respect to a tire radial direction or a tire width direction at least on the adjacent surface.

  According to this configuration, since the groove length of the air discharge groove can be increased as compared with the case where the air discharge groove is provided in the tire radial direction or the tire width direction, the air can be efficiently collected by increasing the air accumulation amount. It can be discharged.

  It is preferable that the inclination direction inclines to the opposite side to the rotation direction of the raw tire at the time of stitching as the stitching tool is moved in the direction of stitching.

  According to this configuration, at the time of stitching, the air discharge groove can be inclined in the push-out direction of the air pushed out by the stitching tool. Thereby, the air between members can be more efficiently discharged.

  It is preferable that the first air discharge groove and / or the second air discharge groove has a linear portion extending linearly at least at a part thereof.

  According to this configuration, the air discharge groove can be easily formed.

  It is preferable that the first air discharge groove and / or the second air discharge groove has an arc portion extending in an arc shape at least partially.

  According to this configuration, the air discharge groove can be formed long, and this makes it easier to increase the amount of accumulated air.

  The invention according to another aspect of the present invention is a method for manufacturing a pneumatic tire, wherein the first air discharge groove for guiding the air interposed between the plurality of tire constituent members to the outside is provided at least in another tire constitution. A first tire constituent member provided on a surface adjacent to the member, and a second air exhaust groove adjacent to the first tire constituent member via the adjacent surface and intersecting the first air exhaust groove, at least A raw tire is formed by bonding the second tire constituent member provided on the adjacent surface, and at least one of the first air discharge groove and the second air discharge groove proceeds in a direction in which the stitching tool is moved. Accordingly, the raw tire is inclined to the opposite side with respect to the direction in which the raw tire is rotated at the time of stitching, and the stitching tool is applied to the raw tire while rotating the raw tire in the direction. By sticking, the air interposed between the plurality of tire constituent members is pushed out to the outside through the first air discharge groove and / or the second air discharge groove, and the green tire is molded in the tire vulcanization mold It is characterized by vulcanization molding.

  According to the pneumatic tire and the method of manufacturing the pneumatic tire according to the present invention, air interposed between a plurality of tire constituent members can be efficiently discharged in the state of a raw tire.

The half sectional view in the meridian of the pneumatic tire concerning one embodiment of the present invention. FIG. 3 is an X arrow view of the raw tire of FIG. 1 as viewed from the X arrow of FIG. 2. The enlarged view which expands and shows the Y section of FIG. Sectional drawing in the IV-IV line | wire of FIG. 3 which shows an air discharge groove | channel. Sectional drawing in the IV-IV line of FIG. 3 which shows the modification of an air discharge groove | channel. Sectional drawing in the IV-IV line of FIG. 3 which shows the modification of an air discharge groove | channel. The enlarged view similar to FIG. 3 which shows the effect | action which discharges | emits the air at the time of stitching. The enlarged view similar to FIG. 3 which shows the effect | action which discharges | emits the air at the time of stitching. The enlarged view similar to FIG. 3 which shows the effect | action which discharges | emits the air at the time of stitching. The enlarged view similar to FIG. 3 which shows the air discharge groove | channel which concerns on other embodiment. The enlarged view similar to FIG. 3 which shows the air discharge groove | channel which concerns on other embodiment. The enlarged view similar to FIG. 3 which shows the air discharge groove | channel which concerns on other embodiment.

  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 is different from the actual one. In the following description, the outer side in the tire width direction refers to the direction away from the tread center, and the inner side in the tire width direction refers to the direction toward the tread center.

  FIG. 1 is a half sectional view in the meridian direction of a pneumatic tire 1 according to an embodiment of the present invention. More specifically, a plurality of tire constituent members are attached on a forming drum (not shown). The formed unvulcanized green tire 10 is shown. FIG. 1 also shows the stitching tool 50 with a two-dot chain line. As shown in FIG. 1, the raw tire 10 includes a plurality of tire constituent members such as a tread member 20 (first tire constituent member), a sidewall member 30 (second tire constituent member), a carcass ply 11, and a bead member 12. The inner liner 13, the belt ply 14, the reinforcing ply 15 and the like are bonded together.

  The green tire 10 has a so-called sidewall on tread (SWOT) structure in which an outer diameter side end portion 31 of the sidewall member 30 on the outer side in the tire radial direction overlaps with an outer end portion 21 of the tread member 20 on the outer side in the tire width direction. I am doing. The tread member 20 and the sidewall member 30 are adjacent to each other via the adjacent surface 41. That is, the outer diameter side end portion 31 of the sidewall member 30 covers the surface of the outer end portion 21 of the tread member 20 on the tire circumference via the adjacent surface 41 to form a shoulder portion serving as a tread grounding end region. doing.

  A tread-side air discharge groove 23 (first air discharge groove) is formed in the end portion 21 of the tread member 20 on the outer end surface 22 on the outer side in the tire width direction. On the other hand, a sidewall-side air discharge groove 33 (second air discharge groove) is formed in the sidewall member 30 on the inner end surface 32 on the inner side in the tire width direction. That is, the tread-side air discharge groove 23 and the sidewall-side air discharge groove 33 are formed on the outer end surface 22 of the tread member 20 and the inner end surface 32 of the sidewall member 30 that face each other.

  FIG. 2 shows an X arrow view of the raw tire 10 as viewed from the X direction arrow. As shown in FIG. 2, the tread-side air discharge groove 23 is formed on the outer end surface 22 of the tread member 20 from the inner side to the outer side in the tire radial direction. Similarly, the sidewall-side air discharge groove 33 is formed on the inner end surface 32 of the sidewall member 30 from the inner side to the outer side in the tire radial direction. In the adjacent surface 41 (see also FIG. 1), the tread-side air discharge groove 23 and the sidewall-side air discharge groove 33 intersect at the intersection 42.

  In FIG. 2, a stitching tool 50 is also shown by a two-dot chain line. While the raw tire 10 is rotated in the tire rotation direction R, the stitching tool 50 is moved from the inner side to the outer side in the tire radial direction. Stitching is performed while moving in the moving direction S and pressing the surface of the raw tire 10, and the air interposed between the members of the raw tire 10 is pushed out of the raw tire to bring the members into close contact with each other.

  With reference to FIG. 3, the tread side air discharge groove 23 and the sidewall side air discharge groove 33 will be specifically described. FIG. 3 is an enlarged view of a Y portion in FIG. 2, and shows the vicinity of the intersection 42 of each air discharge groove 23, 33. As shown in FIG. 3, a plurality of tread-side air discharge grooves 23 are formed substantially in parallel at a groove pitch P1 so as to be inclined at an inclination angle A1 with respect to the tire radial direction. The inclination angle A1 is formed so as to incline in the opposite direction to the tire rotation direction R during stitching as the stitching tool 50 moves in the moving direction S (see FIG. 2), that is, from the inside to the outside in the tire radial direction. Has been.

  A plurality of sidewall-side air discharge grooves 33 are formed substantially in parallel at a groove pitch P2 so as to be inclined at an inclination angle A2 with respect to the tire radial direction. The inclination angle A2 is formed so as to incline in the opposite direction to the tire rotation direction R during stitching as the stitching tool 50 moves in the moving direction S (see FIG. 2), that is, from the inside to the outside in the tire radial direction. Has been. The inclination angle A2 is different from the inclination angle A1, and in this embodiment, the inclination angle A2 is set larger than the inclination angle A1.

  Note that one of the inclination angles A1 and A2 is preferably set to 45 ° to 60 °, and the other is configured to intersect with the one at an intersection angle of 10 ° to 20 °. That's fine. The groove pitches P1 and P2 are set to 6 mm to 8 mm, for example. Further, the groove pitches P1 and P2 and the inclination angles A1 and A2 are such that when the sidewall member 30 is attached to the tread member 20, the plurality of tread side air discharge grooves 23, the plurality of sidewall side air discharge grooves 33, Are set so as to intersect at the adjacent surface 41.

  That is, one of the tread-side air discharge grooves 23 intersects with one of the sidewall-side air discharge grooves 33 at at least one intersection 42. By crossing the air discharge grooves 23 and 33 on the adjacent surface 41, it is possible to prevent the air discharge grooves 23 and 33 from matching with each other. As a result, problems remaining in the pneumatic tire are prevented.

  4A to 4C are cross-sectional views taken along the line IV-IV in FIG. 3, and are cross-sectional views of the air discharge grooves 23 and 33. 4A, in the present embodiment, the tread side air discharge groove 23 and the sidewall side air discharge groove 33 are formed in a substantially trapezoidal shape. Thereby, at the time of vulcanization molding, the air discharge grooves 23 and 33 are easily closed from the groove bottom side, and the air discharge grooves 23 and 33 are eliminated so that air remains in the vulcanized pneumatic tire. It is preventing. The groove width W1 of each of the air discharge grooves 23 and 33 is preferably 0.1 mm to 0.5 mm, and the groove depth D1 is preferably 0.1 mm to 0.3 mm.

  The cross-sectional shape of each of the air discharge grooves 23 and 33 is not limited to a trapezoidal shape. For example, the air discharge grooves 23 and 33 may be formed in a triangular shape as shown in FIG. 4B or in a semicircular shape as shown in FIG. 4C. Also good. That is, the cross-sectional shape of each of the air discharge grooves 23 and 33 may be formed so that the groove width becomes narrower from the opening side toward the groove bottom side, and various groove shapes can be adopted.

  Next, a method for manufacturing the pneumatic tire 1 from the raw tire 10 described above will be described.

  First, as shown in FIG. 1, a plurality of tire constituent members are bonded on a forming drum (raw tire forming step). At this time, the tread member 20 and the sidewall member 30 are bonded together so that the tread-side air discharge groove 23 and the sidewall-side air discharge groove 33 intersect on the adjacent surface 41.

  At this time, an air pocket tends to be generated between the tire constituent members. Specifically, when the tread member 20 is pasted on the carcass ply 11, a step 43 is formed due to the end 21 of the tread member 20, and the sidewall member 30 is further pasted, An air reservoir 44 resulting from the portion 43 is generated. For this reason, in order to eliminate the air pocket 44, stitching is performed next (stitching step).

  5A to 5C sequentially show the action of pushing out air from the air reservoir 44 (see FIG. 1) at the time of stitching, and shows the region stitched first by hatching. First, referring to FIG. 5A, while rotating the raw tire 10 in the tire rotation direction R, the stitching tool 50 is moved in the movement direction S from the inner side to the outer side in the tire radial direction while pressing the surface of the raw tire 10. Let The moving speed of the stitching tool in the tire radial direction is set so that the circumferential trajectory pressing on the surface of the raw tire 10 overlaps with a predetermined pitch in each of the front and rear laps. Stitching is performed over almost the entire surface of the wall member 30 in the range from the inner side to the outer side in the tire radial direction.

  First, the air interposed in the adjacent surface 41 is pushed out to the air discharge grooves 23 and 33 by the stitching tool 50. Next, as shown in FIG. 5B, the air discharged into the air discharge grooves 23 and 33 moves along the extending direction of the air discharge grooves. Next, as shown in FIG. 5C, at the intersection 42 of each air discharge groove 23, 33, the air discharged to one air discharge groove is also discharged to the other air discharge groove. That is, since the air can be dispersed in all directions at the intersection 42, the route for discharging the air can be increased, and the air can be discharged efficiently.

  Moreover, the air discharge grooves 23 and 33 are inclined to the opposite side with respect to the tire rotation direction R during stitching as the stitching tool 50 moves in the moving direction S, that is, from the inner side to the outer side in the tire radial direction. The air discharge grooves 23 and 33 can be inclined in the direction in which the air is pushed out by the stitching tool 50, whereby the air can be discharged more efficiently.

  In this way, air in which the interposition of air between the tire constituent members is suppressed by vulcanizing and molding the raw tire 10 subjected to stitching in a tire vulcanization mold (not shown). An inset tire is manufactured (vulcanization molding step).

  According to the raw tire described above, the following effects can be exhibited.

  Since the tread-side air discharge groove 23 and the sidewall-side air discharge groove 33 intersect at the adjacent surface 41, the air that is interposed between the tread member 20 and the sidewall member 30 is used as the air discharge groove 23, It can be pushed out to one side of 33 and dispersed in both air discharge grooves 23, 33 via the intersection 42. As a result, the air discharge path can be increased and the amount of accumulated air can be increased, so that the air interposed between the plurality of tire constituent members in the raw tire can be efficiently discharged.

  Since the air discharge grooves 23 and 33 are inclined with respect to the tire radial direction, the air discharge paths of the air discharge grooves 23 and 33 can be made longer than when the air discharge grooves are provided in the tire radial direction. Air can be efficiently discharged by increasing the amount of accumulated air.

  Since the air discharge grooves 23 and 33 are inclined to the opposite side with respect to the tire rotation direction R during stitching as the stitching tool 50 moves in the moving direction S, they are pushed out by the stitching tool 50 during stitching. The air discharge groove extends in the direction in which the air is pushed out. Thereby, at the time of stitching, the air interposed between the tread member 20 and the sidewall member 30 can be more efficiently discharged.

  Since the air discharge grooves 23 and 33 are formed linearly, the air discharge grooves 23 and 33 can be easily formed.

  In the above embodiment, the air discharge grooves 23 and 33 are configured in a straight line. However, as shown in FIG. 6, for example, the sidewall-side air discharge grooves 33 may be formed in an arc shape. Thereby, the air discharge path of the air discharge groove 33 can be lengthened, and the amount of accumulated air can be further increased. Further, the air discharge grooves 23 and 33 may be formed so as to intersect each other on the adjacent surface 41. Although not illustrated, the tread side air discharge groove 23 may be formed on an arc, and both the air discharge grooves 23 are formed. 33 may be formed on an arc.

  Moreover, in the said embodiment, although both the air exhaust grooves 23 and 33 were inclined, as shown in FIG. 7, you may incline at least one and may form the other in a tire radial direction. Moreover, in the said embodiment, although the groove pitch P1, P2 of both the air discharge grooves 23 and 33 was substantially equivalent, as shown in FIG. 8, the groove pitch P2 of the side wall side air discharge groove 33 is made more, for example. It may be fine. Thereby, the accumulation amount of air can be increased.

  In the above embodiment, the SWOT structure has been described as an example. However, the present invention is not limited to this, and a tread over sidewall (TOS) in which the end portion 21 of the tread member 20 overlaps the end portion 31 of the sidewall member 30 is described. It may be applied to the structure. Moreover, you may form not only in the adjacent surface 41 of the tread member 20 and the sidewall member 30, but in the adjacent surface with another tire structural member. Moreover, it is applicable not only to the adjacent surfaces of two tire constituent members but also to the adjacent surfaces of three or more tire constituent members.

  Further, in the above embodiment, the case where the stitching tool is moved from the inner side to the outer side in the tire radial direction and the stitching is performed has been described as an example. It can also be applied when moving from the outside to the inside. In this case, each air discharge groove may be inclined to the opposite side with respect to the tire rotation direction at the time of stitching as the stitching tool moves, that is, from the outer side to the inner side in the tire radial direction.

  Moreover, although the said embodiment demonstrated taking the case of the air exhaust groove extended along a tire radial direction as an example, you may apply not only to this but to the air exhaust groove extended along a tire width direction. In this case, for example, in a raw tire having a TOS structure, an air discharge groove is provided between the outer end of the tread member in the tire width direction and the outer end of the sidewall member in the tire radial direction. Just do it. Also, the tread portion can be suitably applied to a case where a plurality of tire constituent members are laminated, and an air discharge groove may be provided on an adjacent surface of each tire constituent member. Each air discharge groove should just incline to the opposite side to the tire rotation direction at the time of stitching as it advances in the direction in which the stitching tool is moved.

  Next, the verification test was implemented about the effect demonstrated above. 10 tires and 10 comparative examples were produced by stitching and vulcanizing raw tires in which tread members and sidewall members were bonded to each other with a common tire size. The pneumatic tire according to the example is the pneumatic tire 1 described in the above embodiment, and air discharge grooves that are inclined with respect to the tire radial direction are formed on adjacent surfaces of the tread member and the sidewall member. Each air discharge groove was provided so as to be inclined to the opposite side with respect to the tire rotation direction at the time of stitching as the stitching tool moved in the moving direction.

  The pneumatic tire according to the comparative example has no air discharge groove. And about each pneumatic tire, the presence or absence of the air interposed between a tread member and a sidewall member was investigated. As a result, in the pneumatic tire according to the comparative example, air was interposed between the tread member and the sidewall member. However, in the pneumatic tire according to the example, the air was interposed between the tread member and the sidewall member. Was not intervening.

DESCRIPTION OF SYMBOLS 10 Raw tire 11 Carcass ply 12 Bead member 13 Inner liner 14 Belt ply 15 Reinforcement ply 20 Tread member 21 Outer end portion 22 Outer end surface 23 Tread side air discharge groove 30 Side wall member 31 Outer diameter side end portion 32 Inner end surface 33 Side wall Side air discharge groove 41 Adjacent surface 42 Intersection 43 Step 44 Air pool 50 Stitching tool

Claims (6)

A raw tire formed by laminating a plurality of tire constituent members, is a pneumatic tire formed by vulcanization molding,
The plurality of tire constituent members in an unvulcanized state,
First tire constituent member provided with at least a first air discharge groove for exhausting air intervening between other tire constituent members adjacent to each other at the time of stitching on at least a surface adjacent to the other tire constituent member When,
A second tire constituent member that is adjacent to the first tire constituent member via the adjacent face and includes a second air exhaust groove that intersects the first air exhaust groove at least on the adjacent face. A pneumatic tire.   2. The at least one of the first air discharge groove and the second air discharge groove extends in an inclined direction inclined with respect to a tire radial direction or a tire width direction at least on the adjacent surface. Pneumatic tires.   The pneumatic according to claim 2, wherein the inclination direction is inclined to an opposite side to a rotation direction of the raw tire at the time of stitching as the stitching tool is moved in a direction to move at the time of stitching. tire.   The said 1st air exhaust groove and / or the said 2nd air exhaust groove have a linear part extended in linear form in at least one part, The Claim 1 or Claim 3 characterized by the above-mentioned. Pneumatic tire.   5. The first air discharge groove and / or the second air discharge groove has an arc portion extending in an arc shape at least at a part thereof, according to claim 1. Pneumatic tire. A pneumatic tire manufacturing method comprising:
A first tire constituent member having a first air discharge groove for guiding air interposed between a plurality of tire constituent members to the outside at least on a surface adjacent to the other tire constituent member; A raw tire is formed by laminating a second tire constituent member that is adjacent to one tire constituent member and that has a second air exhaust groove that intersects the first air exhaust groove at least on the adjacent surface; As at least one of the first air discharge groove and the second air discharge groove advances in the direction in which the stitching tool is moved, the first air discharge groove and the second air discharge groove are inclined to the opposite side to the direction in which the raw tire is rotated during stitching. And
By pressing the stitching tool against the raw tire while rotating the raw tire in the direction, the air interposed between the plurality of tire constituent members is changed to the first air discharge groove and / or the second. Extrude to the outside through the air discharge groove,
A method for producing a pneumatic tire, wherein the green tire is vulcanized and molded in a tire vulcanization mold.

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