JP2014104771A - Pneumatic tire and manufacturing method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire that does not impair uniformity, improves a high-speed durability performance and prevents a single flow caused by a ply-steer.SOLUTION: A tread rubber 10 is formed by a ribbon rubber 20 which is wound around a tire rotary shaft from a winding starting end S1 to a winding terminal E1 without interruption. A position of the winding starting end S1 is located at a tread center part Ce and a position of the winding terminal E1 is located at a tread end T2, and thereby the position of the winding starting end S1 is different from the position of the winding terminal E1 in a tire width direction WD. When a belt inclined side is a side where a cord C of a belt ply 6a outermost-side in a tire radial direction among a plurality of belt plies is inclined to a tire circumferential direction CD, the ribbon rubber 20 is wound while being inclined opposite to the belt inclined side to the tire circumferential direction CD.

Description

  The present invention relates to a pneumatic tire having a tread rubber and a manufacturing method thereof.

  Conventionally, a so-called ribbon winding method has been proposed in which tread rubber is formed on the outer peripheral surface of a substantially cylindrical rotating support body by spirally winding unvulcanized ribbon rubber around the tire rotation axis while overlapping the side edges. Has been.

  As an example of a pneumatic tire in which a tread rubber is formed by a ribbon winding method, for example, in Patent Document 1, a ribbon rubber is wound from a starting point located at a tread central portion in a tire meridian section toward one side in a tire width direction. Then, it is folded back to the other side in the tire width direction at the tread end on one side and wound toward the tread end on the other side beyond the start point, and the winding start end and winding end of the ribbon rubber are the central part of the tread rubber. A pneumatic tire disposed in the vicinity of the tire equator is disclosed.

JP 2006-130880 A

  However, in the pneumatic tire as in Patent Document 1, the winding start end and the winding end of the ribbon rubber are both arranged at the center of the tread, and the winding start end and the winding end of the ribbon rubber overlap with each other when viewed from the tire radial direction. Therefore, it cannot be said that it is preferable from the viewpoint of uniformity.

  Further, since the winding end of the ribbon rubber is arranged at the center of the tread, the force acting on the ground surface becomes uneven, and uniformity such as RRO (radial runout) and RFV (radial force variation) is deteriorated. Furthermore, since a large centrifugal force acts in the center of the tread, a failure starting from the winding end is likely to occur, and the high-speed durability performance deteriorates.

  Further, in a general tire provided with a belt layer composed of a plurality of belt plies having a cord inclined with respect to the tire circumferential direction, it is caused by the expansion and contraction of the cord of the belt ply that is the outermost in the radial direction. As a result, the power of pricetea is developed. The price tear is preferably as small as possible because it causes the tire to flow partly with rolling.

  The present invention has been made paying attention to such a problem, the purpose of which is to improve the high-speed durability performance without impairing the uniformity, and a pneumatic tire that suppresses the single flow of the tire caused by the price tear, and The manufacturing method is provided.

  In order to achieve the above object, the present invention takes the following measures.

That is, the pneumatic tire of the present invention is provided with a belt layer formed of a plurality of belt plies provided on the tread portion and having a cord inclined with respect to the tire circumferential direction, and the tire diameter of the belt layer in the tread portion. With tread rubber placed on the outside in the direction,
The tread rubber is formed of a ribbon rubber wound around the tire rotation axis without interruption from the winding start end to the winding end,
By positioning the winding start end in the tread center and the winding end in the tread end, the positions of the winding start end and the winding end in the tire width direction are different from each other,
When the side of the plurality of belt plies where the belt ply cord on the outermost side in the tire radial direction is inclined with respect to the tire circumferential direction is the belt inclined side, at least a part of the ribbon rubber is in the tire circumferential direction. On the other hand, the belt is wound in a posture inclined to the opposite side to the belt inclined side.

  The central portion of the tread means within 10% of the maximum width of the belt ply that is the outermost in the tire radial direction from the tire equator toward the outer side in the tire width direction. Further, the tread end portion means a range of 20% of the maximum width of the tread rubber from the tread end toward the center side.

  As described above, since at least a part of the ribbon rubber is wound in a posture inclined to the opposite side of the belt inclination side with respect to the tire circumferential direction, a force is developed in a direction to cancel the price tear depending on the winding posture of the ribbon rubber. Thus, it is possible to suppress the single flow of the tire caused by the price tear. Nevertheless, the positions of the winding start end and winding end in the tire width direction are different from each other, which is preferable from the viewpoint of uniformity. Furthermore, since the winding end is located at the tread end, uniformity such as RRO (radial runout) and RFV (radial force variation) is improved and high-speed durability performance is improved as compared with the case where the winding end is located at the center of the tread. It becomes possible.

  In order to further reduce the price tear, the cord of the belt ply located on the outermost side in the tire radial direction extends from one side in the tire width direction to the other side in the tire width direction from the delay side to the advance side in the tire rotation direction. In this case, the ribbon rubber is preferably wound so that the winding density is higher on one side in the tire width direction than on the other side in the tire width direction.

  In order to make it easy to manufacture a tire having a difference in winding density, the ribbon rubber is wound from the starting point located at the center of the tread toward the other side in the tire width direction, and then the tread on the other side in the tire width direction. Folded to one side in the tire width direction at the end, wound toward the tread end on one side in the tire width direction, and terminated at one end of the tread on one side in the tire width direction or the other side in the tire width direction, It is preferable that one side in the tire width direction of the tread rubber is formed in an N layer structure (N is a natural number of 1 or more), and the other side in the tire width direction of the tread rubber is formed in an (N + 1) layer structure.

  In order to further suppress the tire single flow caused by the price tear, the ribbon rubber is spirally wound over the entire region in the tire circumferential direction so as to be inclined to the opposite side of the belt inclined side with respect to the tire circumferential direction. It is preferable.

The pneumatic tire is manufactured by the following manufacturing method. That is, the method for manufacturing a pneumatic tire according to the present invention includes a belt layer including a plurality of belt plies provided on a tread portion and having a cord inclined with respect to a tire circumferential direction, and the belt layer in the tread portion. A method of manufacturing a pneumatic tire comprising a tread rubber disposed on the outer side in the tire radial direction,
A tread rubber molding step of forming the tread rubber by winding the ribbon rubber around the tire rotation axis without interruption from the winding start end to the winding end;
In the tread rubber forming step, the winding start end is arranged in the tread central part and the winding end is arranged in the tread end part so that the positions of the winding start end and the winding end in the tire width direction are different from each other. With
When the side of the plurality of belt plies where the belt ply cord on the outermost side in the tire radial direction is inclined with respect to the tire circumferential direction is the belt inclined side, at least a part of the ribbon rubber is in the tire circumferential direction. On the other hand, the belt is wound in a posture inclined to the opposite side to the belt inclined side.

  By implementing this manufacturing method, the same effects as described above can be achieved.

1 is a tire meridian cross-sectional view showing a pneumatic tire according to an embodiment of the present invention. The figure which shows the manufacturing equipment used at the formation process of a tread rubber. A typical sectional view of ribbon rubber. Sectional drawing which shows the shaping | molding process of a tread rubber roughly. Sectional drawing which shows the shaping | molding process of a tread rubber roughly. Sectional drawing which shows the shaping | molding process of a tread rubber roughly. Sectional drawing which shows the shaping | molding process of a tread rubber roughly. The figure which shows typically the relationship between the inclination attitude | position of the code | cord | chord of the 2nd belt ply which becomes the tire radial direction outer side, and a tire rotation direction. The top view which shows the winding process of ribbon rubber. The conceptual diagram which shows the movement path | route of the ribbon winding position of this embodiment. The conceptual diagram which shows the movement path | route of the ribbon winding position which concerns on other embodiment. The top view which shows the winding process of the ribbon rubber which concerns on other embodiment. The conceptual diagram which shows the movement path | route of the ribbon winding position which concerns on other embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. First, the configuration of the pneumatic tire of the present invention will be described, and then the method for manufacturing the pneumatic tire according to the present invention will be described.

[Composition of pneumatic tire]
A pneumatic tire T shown in FIG. 1 includes a pair of bead portions 1, sidewall portions 2 extending outward in the tire radial direction from each of the bead portions 1, and tire radial direction outer ends of the sidewall portions 2. And a tread portion 3 that is connected to the tread. The bead portion 1 is provided with an annular bead core 1a formed by covering a converging body such as a steel wire with rubber and a bead filler 1b made of hard rubber.

  A toroid-like carcass layer 7 is disposed between the pair of bead portions 1 and the ends thereof are locked in a state of being wound up via the bead core 1a. The carcass layer 7 is composed of at least one (two in this embodiment) carcass ply, and the carcass ply is formed by covering a cord that extends at an angle of approximately 90 ° with respect to the tire circumferential direction with a topping rubber. Has been. An inner liner rubber 5 for maintaining air pressure is disposed on the inner periphery of the carcass layer 7.

  In the bead portion 1, a rim strip rubber 4 that is in contact with a rim (not shown) when the rim is mounted is provided outside the carcass layer 7. In the sidewall portion 2, sidewall rubber 9 is provided outside the carcass layer 7. In the present embodiment, the rim strip rubber 4 and the sidewall rubber 9 are each formed of conductive rubber.

  In the tread portion 3, a belt layer 6 composed of a plurality of (two in this embodiment) belt plies is disposed outside the carcass layer 7. Each belt ply is formed by covering a cord extending obliquely with respect to the tire circumferential direction with a topping rubber, and the cords are laminated so that the cords cross each other in opposite directions. In the present embodiment, the radially inner belt ply of the plurality of belt plies is called a first belt ply, and the outermost belt ply of the tire radial direction is called a second belt ply 6a.

  In the tread portion 3, a tread rubber 10 is provided on the outer periphery of the belt layer 6. The tread rubber 10 includes a cap portion 12 that constitutes a ground contact surface, and a base portion 11 that is provided on the inner side in the tire radial direction of the cap portion 12. The base 11 is made of a rubber different from the cap 12.

  Examples of the raw rubber such as the rubber layer described above include natural rubber, styrene butadiene rubber (SBR), butadiene rubber (BR), isoprene rubber (IR), butyl rubber (IIR), and the like. Used in combination with more than one species. These rubbers are reinforced with fillers such as carbon black and silica, and a vulcanizing agent, a vulcanization accelerator, a plasticizer, an anti-aging agent and the like are appropriately blended.

  The tread rubber 10, especially the cap portion 12, is formed by a so-called ribbon winding method. The ribbon winding method is a method of forming a rubber member having a desired cross-sectional shape by winding the unvulcanized ribbon rubber 20 having a small width shown in FIG. 3 in a spiral manner around the tire rotation axis (see FIGS. 2 and 6). is there. The tread rubber 10 formed by the ribbon winding method has a winding start end S1 and a winding end E1 of the ribbon rubber 20 as shown in FIG. The winding start end S1, the winding end E1, and the movement path of the winding position can be confirmed in the tire meridian cross section. Details will be described later.

  Further, a main groove 15 extending in the tire circumferential direction is formed on the surface of the tread rubber 10 by being vulcanized. The tire mold used for the vulcanization process is provided with protrusions, and the main grooves 15 are formed by pressing the protrusions against the tread rubber 10. Although not shown, the tread rubber 10 is also appropriately provided with a transverse groove extending in a direction intersecting the main groove 15.

[Pneumatic tire manufacturing method]
Next, a method for manufacturing the pneumatic tire T will be described. Since the pneumatic tire T can be manufactured in the same manner as the conventional tire manufacturing process except for the point related to the tread rubber 10, the description will focus on the molding process of the tread rubber 10.

  The tread rubber 10 shown in FIG. 1 is formed by the ribbon winding method. As shown in FIG. 2, the molding process of the tread rubber 10 includes a step of winding the ribbon rubber 20 supplied from the ribbon rubber molding device 30 around the rotary support 31 while rotating the rotary support 31. As shown in FIG. 3, the rubber ribbon 20 is made of non-conductive rubber. At the time of winding, the lower side in FIG. 3 is the inner peripheral side facing the rotation support 31. The width and thickness of the ribbon rubber (also referred to as rubber strip) are not particularly limited, but preferably the width is 15 to 40 mm and the thickness is 0.5 to 3.0 mm.

  As shown in FIG. 2, the ribbon rubber molding apparatus 30 is configured to be able to mold the ribbon rubber 20 by extruding rubber. The rotary support 31 is configured to be capable of rotating in the R direction around the shaft 31a and moving in the axial direction. The control device 32 controls the operation of the ribbon rubber molding device 30 and the rotary support 31. In the present embodiment, the cross section of the ribbon rubber 20 is triangular, but is not limited thereto, and may be another shape such as an ellipse or a quadrangle. Further, although the rotary support 31 is configured to be movable in the axial direction, the ribbon rubber molding device 30 may be moved relative to the rotary support 31. That is, it is only necessary that the rotary support 31 is configured to be relatively movable along the axial direction with respect to the ribbon rubber molding apparatus 30.

  In the process of forming the tread rubber 10, first, the base portion 11 is formed on the outer peripheral surface of the rotary support 31 as shown in FIG. 4A. Although not shown, the belt layer 6 is provided in advance on the outer peripheral surface of the rotary support 31 (see FIG. 1), and the base portion 11 is formed thereon. The base portion 11 may be formed by either a so-called extrusion molding method or a ribbon winding method. The extrusion molding method is a method of extruding an unvulcanized belt-like rubber member having a desired cross-sectional shape, and joining the end portions to form an annular shape.

  Here, for convenience of explanation, one side (left side in the figure) of the tire width direction WD in the tire meridian section is WD1, and the other side is WD2 (right side in the figure).

  Next, as sequentially shown in FIGS. 4B, 4C, and 4D, the cap portion 12 is formed on the outer peripheral surface of the base 11, and the tread rubber 10 shown in FIG. 1 is molded. FIG. 5 shows the state of the belt ply 6a (second belt ply in the present embodiment) that is the outermost in the tire radial direction among the plurality of belt plies and the cord C thereof. In this case, with the rotation of the tire, a force called a price tear from the one side WD1 in the tire width direction toward the other side WD2 in the tire width direction appears. As shown in FIG. 6, when the side where the cord C of the second belt ply 6a is inclined with respect to the tire circumferential direction CD is the belt inclined side, as shown in FIG. On the other hand, the belt is wound in a posture inclined to the opposite side to the belt inclined side. By such an inclined posture of the ribbon rubber 20, a force is developed in a direction to cancel the price tear.

  As shown in FIG. 6, the winding pitch P20 of the ribbon rubber 20 is set smaller than the ribbon width W20 of the ribbon rubber 20. As a result, the adjacent ribbon rubbers 20 and 20 are wound spirally in a state where they are in contact with each other. An arrow D indicates a moving direction of the ribbon winding position, and adjacent ribbon rubbers 20 overlap each other along this direction.

  In the present embodiment, as shown in FIG. 6, the ribbon rubber 20 is spirally wound over the entire region in the tire circumferential direction CD in a posture that is inclined to the opposite side to the belt inclined side with respect to the tire circumferential direction CD. It is not limited to this. For example, so-called pitch feed winding can be mentioned. As shown in FIG. 9, in the pitch feed winding, every time the ribbon rubber 20 is wound once along the tire circumferential direction CD, the winding position of the ribbon rubber 20 is inclined to the opposite side of the belt inclined side with respect to the tire circumferential direction CD. Is a way of winding to move. As shown in FIG. 6, the spiral winding is performed in such a manner that almost all of the ribbon rubber 20 is inclined with respect to the tire circumferential direction CD. On the other hand, the pitch feed winding is performed in such a manner that only a part of the ribbon rubber 20 is inclined with respect to the tire circumferential direction CD.

  In the present embodiment, as shown in FIG. 5, an example in which the cord C of the belt ply 6a rises to the right is given, but in the case of the left shoulder rising, the inclined posture of the ribbon rubber is reversed.

  The winding pitch P20 of the ribbon rubber 20 may be constant throughout the tire width direction WD. However, in order to further reduce the price tear, it is preferable that the one side WD1 in the tire width direction and the other side WD2 in the tire width direction are different. Specifically, as shown in FIG. 5, in the tire T in which the rotation direction RO is specified (the tire whose rotation direction or the mounting direction with respect to the vehicle is displayed on the outer surface such as the tire side), the outermost in the tire radial direction. When the cord C of the belt ply 6a is extended from the tire width direction one side WD1 to the tire width direction other side WD2 from the delay side RO2 of the tire rotation direction RO toward the advance side RO1, the ribbon rubber 20 Winding is performed such that the winding density is higher on the one side WD1 in the width direction than on the other side WD2 in the tire width direction. When the thickness of the ribbon rubber 20 is constant, the winding density increases as the winding pitch P20 of the ribbon rubber 20 is reduced, and decreases as the winding pitch P20 is increased. If comprised in this way, the force called conicity which goes to the tire width direction one side WD1 with a high density from the tire width direction other side WD2 with a low density will express in the direction which cancels a price tear.

  FIG. 7 conceptually shows the movement path of the winding position of the ribbon rubber 20 in the tread rubber molding step shown in FIG. The ribbon rubber is wound around the tire meridian section from the starting point located at the tread center portion Ce toward the other side WD2 in the tire width direction. Next, the tire is folded back to one side WD1 in the tire width direction at the tread end P2 on the other side WD2 of the tire width direction and wound toward the tread end P1 on the one side WD1 in the tire width direction. Next, it is folded back to the other side WD2 in the tire width direction at the tread end P1 on the one side WD1 in the tire width direction, and ends at the end point E1 located at the tread end T2 on the other side WD2 in the tire width direction. With such a winding method, the tire width direction one side WD1 of the tread rubber 10 has an N layer structure (N = 2 in this embodiment), and the tire width direction other side WD2 of the tread rubber 10 is (N + 1). It becomes a layer structure. As a result, if the winding pitch is adjusted so that the thickness of the tread rubber 10 is constant, the structure will naturally have a difference in winding density between the one side WD1 and the other side WD2 in the tire width direction, and it is easy to manufacture. Become.

  As shown in FIG. 7, the tread central portion Ce means the range of 10% of the maximum width WB of the belt ply 6a that is the outermost in the tire radial direction from the tire equator CL toward the outer side in the tire width direction WD. . Further, the tread end portions T1 and T2 mean a range of 20% of the maximum tread rubber width W from the tread ends P1 and P2 toward the center side. The winding start end S1 and the winding end E1 of the ribbon rubber are arranged so that the positions in the tire width direction WD are different.

  The winding end E1 is disposed at the tread end portions T1 and T2, but is preferably disposed outside the ground contact end in the tire width direction. The ground contact edge is the outermost position of the ground contact surface in the tire width direction WD. The ground contact surface is a surface that is assembled to a regular rim and filled with a regular internal pressure so that the tire is placed vertically on a flat road surface and contacts the road surface when a normal load is applied. The regular rim is a standard rim defined in JIS D4202, etc. as a rule, and the regular load is 0 of the maximum load (design normal load in the case of passenger car tires) defined in JIS D4202 (specifications of automobile tires). .8 times the load, and the normal internal pressure is the air pressure commensurate with the above maximum load.

  Further, it is preferable that the winding start end S1 and the winding end E1 are arranged 180 degrees apart in the tire circumferential direction and symmetrical with respect to the tire rotation axis as viewed from the tire rotation axis.

  Furthermore, it is preferable that the winding end E1 is disposed at a location where the main groove 15 extending in the tire circumferential direction CD is formed. Specifically, the winding end E1 is disposed on the inner side in the tire radial direction of the main groove 15 in the tire meridian cross section.

  As described above, the pneumatic tire according to the present embodiment includes the belt layer 6 that is provided in the tread portion 3 and includes a plurality of belt plies having cords that are inclined with respect to the tire circumferential direction CD. A tread rubber 10 disposed on the outer side of the belt layer 6 in the tire radial direction, and the tread rubber 10 is formed of a ribbon rubber 20 wound around the tire rotation axis without interruption from the winding start end S1 to the winding end E1. Since the winding start end is located at the tread center and the winding end is located at the tread end, the positions of the winding start end S1 and the winding end E1 in the tire width direction are different from each other, and the tire diameter is the largest of the plurality of belt plies. The cord C of the belt ply 6a on the outer side in the direction is inclined with respect to the tire circumferential direction CD. When the side that has the belt inclined side, at least a portion of Ribongomu 20 is wound in a posture inclined in the opposite side to the belt inclined side with respect to the tire circumferential direction CD.

  Moreover, the pneumatic tire of this embodiment is produced by the following manufacturing method. That is, the pneumatic tire manufacturing method according to the present embodiment includes a belt layer 6 including a plurality of belt plies provided on the tread portion 3 and having a cord inclined with respect to the tire circumferential direction CD, and the tread portion 3. And a tread rubber 10 disposed outside the belt layer 6 in the tire radial direction in which a ribbon rubber 20 is wound around the tire rotation axis without interruption from the winding start end S1 to the winding end E1. A tread rubber molding step of forming the tread rubber 10 by the step, and in the tread rubber forming step, the winding start end S1 and the winding start end S1 are arranged at the tread center portion and the winding end end is arranged at the tread end portion. The positions of the winding end E1 in the tire width direction WD are different from each other. In addition, when the cord C of the belt ply 6a that is the outermost in the tire radial direction among the plurality of belt plies is inclined with respect to the tire circumferential direction CD, at least a part of the ribbon rubber 20 is used. Winding is performed in such a manner that it is inclined to the opposite side of the belt inclination side with respect to the tire circumferential direction CD.

  As described above, since at least a part of the ribbon rubber is wound in a posture inclined to the opposite side of the belt inclination side with respect to the tire circumferential direction, a force is developed in a direction to cancel the price tear depending on the winding posture of the ribbon rubber. Thus, it is possible to suppress the single flow of the tire caused by the price tear. Nevertheless, the positions of the winding start end S1 and the winding end E1 in the tire width direction WD are different from each other, which is preferable from the viewpoint of uniformity. Furthermore, since the winding end is located at the tread end, uniformity such as RRO (radial runout) and RFV (radial force variation) is improved and high-speed durability performance is improved as compared with the case where the winding end is located at the center of the tread. It becomes possible.

  In particular, in the present embodiment, the cord C of the belt ply 6a located on the outermost side in the tire radial direction increases from the tire width direction one side WD1 to the tire width direction other side WD2 from the delay side RO2 to the advance side RO1 in the tire rotation direction RO. The ribbon rubber 20 is wound such that the winding density is higher on the one side WD1 in the tire width direction than on the other side WD2 in the tire width direction.

  According to this configuration, a force called price tear is developed from the tire width direction one side WD1 toward the tire width direction other side WD2 as the tire rotates. However, since the winding density of the ribbon rubber 20 is higher on the one side WD1 in the tire width direction than on the other side WD2 in the tire width direction, a force called conicity appears in the direction of canceling the price tear, thereby further reducing the price tear. It becomes possible.

  Furthermore, in this embodiment, the ribbon rubber 20 is wound from the starting point S1 located at the tread center portion Ce toward the other side WD2 in the tire width direction, and then at one side in the tire width direction at the tread end P2 of the other side WD2 in the tire width direction. Folded back to WD1, wound around tread end P1 on one side WD1 in the tire width direction, and terminated at tread end portion T2 on the other side WD2 in the tire width direction, so that one side in the tire width direction of tread rubber 10 has N layers. The structure (N is a natural number of 1 or more) is formed, and the other side in the tire width direction of the tread rubber is formed in an (N + 1) layer structure.

  According to this configuration, it is possible to appropriately wind the ribbon rubber while changing the positions of the winding start end S1 and the winding end E1 of the ribbon rubber 20 in the tire width direction WD. Furthermore, if the winding pitch is adjusted so that the thickness of the tread rubber 10 is constant, the structure will naturally have a difference in winding density between the one side WD1 and the other side WD2 in the tire width direction. Tires with a difference are easy to manufacture.

  Further, in the present embodiment, the ribbon rubber 20 is spirally wound over the entire region in the tire circumferential direction CD in such a posture that the ribbon rubber 20 is inclined to the side opposite to the belt inclined side with respect to the tire circumferential direction CD.

  According to this configuration, since the force for canceling the price tear is stronger than that of the pitch feed winding, it is possible to further suppress the single flow of the tire caused by the price tear.

  Further, in the present embodiment, the winding start end S1 and the winding end E1 are arranged 180 degrees apart in the tire circumferential direction and symmetrical with respect to the tire rotation axis as viewed from the tire rotation axis. According to this configuration, uniformity such as RFV (radial force variation) is improved and the contact pressure distribution on the circumference is uniform, so that high-speed durability performance can be improved.

  Further, in the present embodiment, the winding end E1 is disposed at a location where the main groove 15 extending in the tire circumferential direction CD is formed. The formation location of the main groove 15 is such that the thickness of the rubber is reduced, and accordingly, heat generation during high-speed rotation is suppressed, so that failure due to heat generation can be suppressed, and high-speed durability performance can be further improved.

[Other Embodiments]
(1) The movement path of the winding position of the ribbon rubber 20 may be reversed not only as shown in FIG. 7 but also as shown in FIG.

  (2) In the present embodiment, the non-conductive rubber is used for the ribbon rubber 20, but a conductive rubber may be used, or a ribbon rubber obtained by superimposing the non-conductive rubber and the conductive rubber may be used. 2 shows an example in which one ribbon rubber molding apparatus 30 is used, but a so-called two-shot system using a plurality of ribbon rubber molding apparatuses 30 may be used.

  (3) If the tire width direction one side WD1 of the tread rubber 10 can be formed in an N layer structure and the tire width direction other side WD2 can be formed in an (N + 1) layer structure, an arbitrary movement path can be adopted. For example, as shown in FIG. 10, the tire width direction one side WD1 of the tread rubber 10 may have a two-layer structure, and the tire width direction other side WD2 of the tread rubber 10 may have a three-layer structure.

  The structure employed in each of the above embodiments can be employed in any other embodiment. The specific configuration of each unit is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 10 ... Tread rubber 20 ... Ribbon rubber 3 ... Tread part 6 ... Belt layer 6a ... Belt ply which exists in the tire radial direction outermost side S1 ... Winding start end E1 ... Winding end WD ... Tire width direction WD1 ... Tire width direction one side WD2 ... Tire width Direction other side RO ... Tire rotation direction RO1 ... Tire rotation direction advance side RO2 ... Tire rotation direction delay side T1, T2 ... Tread end CD ... Tire circumferential direction C ... Code Ce ... Tread center

Claims (5)

A belt layer formed of a plurality of belt plies provided on the tread portion and having a cord inclined with respect to the tire circumferential direction; and a tread rubber disposed on the outer side in the tire radial direction of the belt layer in the tread portion. Prepared,
The tread rubber is formed of a ribbon rubber wound around the tire rotation axis without interruption from the winding start end to the winding end,
By positioning the winding start end in the tread center and the winding end in the tread end, the positions of the winding start end and the winding end in the tire width direction are different from each other,
When the side of the plurality of belt plies where the belt ply cord on the outermost side in the tire radial direction is inclined with respect to the tire circumferential direction is the belt inclined side, at least a part of the ribbon rubber is in the tire circumferential direction. On the other hand, the pneumatic tire is wound in such a manner as to be inclined to the side opposite to the belt inclination side.   When the cord of the belt ply located on the outermost side in the tire radial direction extends from one side in the tire width direction to the other side in the tire width direction from the delay side in the tire rotation direction toward the advance side, the ribbon rubber The pneumatic tire according to claim 1, wherein the pneumatic tire is wound so that the winding density is higher on one side in the width direction than on the other side in the tire width direction.   The ribbon rubber is wound from the start point located at the center of the tread toward the other side in the tire width direction, and then folded back to the one side in the tire width direction at the tread end on the other side in the tire width direction, and the tread end on one side in the tire width direction Is wound at the tread end on either the tire width direction one side or the tire width direction other side, so that one side of the tread rubber in the tire width direction is an N-layer structure (N is a natural number of 1 or more) The pneumatic tire according to claim 1, wherein the other side in the tire width direction of the tread rubber is formed in a (N + 1) layer structure.   The pneumatic tire according to any one of claims 1 to 3, wherein the ribbon rubber is wound spirally over the entire region in the tire circumferential direction in a posture that is inclined to the opposite side of the belt inclined side with respect to the tire circumferential direction. A belt layer formed of a plurality of belt plies provided on the tread portion and having a cord inclined with respect to the tire circumferential direction; and a tread rubber disposed on the outer side in the tire radial direction of the belt layer in the tread portion. A pneumatic tire manufacturing method comprising:
A tread rubber molding step of forming the tread rubber by winding the ribbon rubber around the tire rotation axis without interruption from the winding start end to the winding end;
In the tread rubber forming step, the winding start end is arranged in the tread central portion and the winding end is arranged in the tread end portion so that the positions of the winding start end and the winding end in the tire width direction are different from each other. With
When the side of the plurality of belt plies where the belt ply cord on the outermost side in the tire radial direction is inclined with respect to the tire circumferential direction is the belt inclined side, at least a part of the ribbon rubber is in the tire circumferential direction. On the other hand, a method for manufacturing a pneumatic tire is characterized by winding in a posture inclined to the opposite side of the belt inclined side.

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