阅读说明：本技术 竞技用轮椅用轮胎 (Tire for wheelchair for sports ) 是由 佐桥耕平 于 2019-12-10 设计创作，主要内容包括：竞技用轮椅用轮胎的特征在于,在轮胎的胎面着地面的、以轮胎赤道为界的两侧的各区域中,在胎面的整周具备平行地排列有多个凹条的抓着区域,该凹条以比所述胎面着地面的轮廓线向轮胎的内侧凹入的形状从胎面端侧沿相对于轮胎赤道倾斜的方向延伸,在所述各区域中具备凹部,该凹部由两条线和将该两条线的顶端相互连结的线划分形成,该两条线从比所述轮胎赤道靠所述抓着区域侧的一点朝向所述抓着区域以放射状延伸。(The tire for wheelchair for sports is characterized in that a grip region in which a plurality of concave strips are arranged in parallel over the entire circumference of the tread is provided in each of both side regions of the tread surface of the tire, the concave strips being recessed inward of the tire from the tread end side in a shape that is recessed from the contour line of the tread surface in a direction inclined with respect to the tire equator, each region being provided with a recess that is defined by two lines extending radially from a point on the grip region side with respect to the tire equator toward the grip region, and a line connecting the tips of the two lines.)

1. A tire for wheelchair for sports, characterized in that,

in each of the regions on both sides of the tread surface of the tire, which are bounded by the tire equator,

a grip region having a plurality of concave strips arranged in parallel over the entire circumference of the tread, the concave strips extending from the tread end side in a direction inclined with respect to the tire equator in a shape that is concave toward the inside of the tire compared with the contour line of the tread surface,

each of the regions includes a concave portion defined by two lines extending radially from a point on the grip region side with respect to the tire equator toward the grip region, and a line connecting the tips of the two lines to each other.

2. The tire for wheelchair for sports according to claim 1,

concave stripes extending in a plurality of directions and intersecting with respect to the tire equator are arranged in the gripping region.

3. The tire for wheelchair for sports according to claim 1 or 2, wherein,

the gripping region has a plurality of sipes extending in a direction inclined with respect to the tire equator.

4. The tire for wheelchair for sports according to claim 3,

the plurality of sipes have pairs of axisymmetric sipe pairs in which adjacent pairs of sipes are in axisymmetric relationship with a line segment orthogonal to the tire equator as an axis of symmetry,

in the axially symmetric sipe pair, each sipe is inclined in a direction away from the axis of symmetry from the tire equator toward the tread end.

5. The tire for wheelchair for sports according to claim 4,

the axially symmetric sipe pairs are arranged with a phase difference along the tire equator between the regions.

Technical Field

The present invention relates to a tire for use in a wheelchair used in various sports, and particularly to a tire for use in a wheelchair for sports having water drainage and gripping ability with the hand of a user sitting on the wheelchair.

Background

In a self-propelled wheelchair in which a wheelchair user controls the movement of tires by his or her own force, hand rims coaxial with the tires are provided on the outer sides of the tires on both sides of a chair portion in the axial direction, and the wheelchair is moved by the user rotating the hand rims with his or her hands.

Particularly, when a sports competition such as tennis is performed while sitting on a wheelchair for the competition, the competitor needs to quickly respond to the development of the competition to change the action, quickly change the position of the competitor himself or herself, and finely adjust the position, so that the movement of the wheelchair needs to be controlled by directly touching the tire with the hand at the time of the scribing and braking of the wheelchair.

Documents of the prior art

Patent document

Patent document 1: specification of U.S. patent No. 7156407

Disclosure of Invention

Problems to be solved by the invention

Here, when the hands of the player directly touch the tire, if the tire has a raised portion, the hands may be injured by the edge of the raised portion or the like. In order to prevent the hands of players from being injured, for example, the surface of a region of a wheelchair tire, which is touched by the hands, is smooth and has no unevenness as described in patent document 1.

However, in the wheelchair for sports, it is necessary to rotate the tire from a stopped state at a high speed at the time of rowing, and to stop the rotation of the tire in an emergency at the time of braking, and a higher grip between the hand of the player and the tire is required. In this case, the grip between the tire for a wheelchair having a surface property completely free from irregularities and the hand of the user, which is disclosed in patent document 1, is not sufficient.

Further, the tire for a wheelchair described in patent document 1 does not take into consideration a water drainage property for draining water from the tire in the presence of a water film on a ground contact surface. For example, tires for wheelchair for sports used in outdoor sports such as tennis are also used in wet lands after rainy days or on lawn courses. In this case, if a water film is present on the ground contact surface, the water film is present between the tire and the ground contact surface, and the ground contact of the tire is hindered, resulting in slippage and adverse effects on the game. In order to prevent the slippage of the tire, drainage for draining the moisture adhering to the tire is required.

Accordingly, an object of the present invention is to provide a tire for wheelchair for competition having gripping properties with hands and water drainage properties without damaging the hands of a player.

Means for solving the problems

The inventors have intensively studied a solution to the problem. That is, the present inventors have studied in detail a contact region with a ground contact surface and a contact region with a hand of a tire for a wheelchair for competition, and have found that gripping properties and drainage properties with respect to the hand can be provided by designing the surface properties of each of the contact region with the ground contact surface and the contact region with the hand, and have completed the present invention.

The gist of the present invention is as follows.

The tire for wheelchair for sports according to the present invention is characterized in that a grip region in which a plurality of concave strips are arranged in parallel over the entire circumference of the tread is provided in each of both side regions of the tread surface of the tire, the concave strips extending from the tread end side in a direction inclined with respect to the tire equator in a shape recessed inward of the tire from the contour line of the tread surface, and each of the regions is provided with a concave portion formed by dividing two lines extending radially from one point on the grip region side with respect to the tire equator toward the grip region, and a line connecting the tips of the two lines.

Here, the "tread end" refers to the outer end in the width direction of the formation region of the tread pattern formed in accordance with the requirement of each wheelchair tire.

Unless otherwise specified, the position and the size refer to the position and the size in a state of a product tire.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a tire for a wheelchair for competition having gripping properties with hands and water drainage properties without damaging the hands of a competitor can be provided.

Drawings

Fig. 1 (a) is a view showing a part of a tire according to embodiment 1 of the present invention spread in the tread width direction. Fig. 1 (b) is a schematic sectional view taken along line II-II of fig. 1 (a).

Fig. 2A is a sectional view taken along line III-III of fig. 1 (a).

Fig. 2B is a sectional view taken along the line III-III of fig. 1 (a).

Fig. 3A is an enlarged view of the recess in fig. 1 (a).

Fig. 3B is a diagram showing a modification of the recess.

Fig. 3C is a diagram showing a modification of the recess.

Fig. 3D is a diagram showing a modification of the recess.

Fig. 3E is a diagram showing a modification of the recess.

Fig. 4A is a sectional view taken along a line t1 of fig. 3A.

Fig. 4B is a sectional view taken along a line t1 of fig. 3A.

Fig. 5 is a view showing a part of a tire according to embodiment 2 of the present invention spread in the tread width direction.

Fig. 6 is an enlarged view of a part of the grip region of fig. 5.

Fig. 7 is a view showing a part of a tire according to embodiment 3 of the present invention spread in the tread width direction.

Fig. 8 is a view showing a part of a tire according to embodiment 4 of the present invention spread in the tread width direction.

Detailed Description

(1 st mode)

Hereinafter, the present wheelchair tire for sports will be described in detail with reference to the drawings showing an embodiment of the wheelchair tire for sports (hereinafter, also simply referred to as "tire") according to the present invention.

Fig. 1 (a) shows a part of a tread surface 2 of a tire 1 according to embodiment 1 of the present invention spread in a tread width direction, and fig. 1 (b) is a schematic cross section along line II-II of fig. 1 (a). Fig. 2A shows a cross section along the line III-III in fig. 1 (a). The internal structure of the tire 1 is not limited, and although not shown, from the viewpoint of durability, it is preferable that a carcass spanning between a pair of bead portions be a frame and that the carcass have a tread on the outer side in the tire radial direction.

The tire 1 has a grip region 4a and a grip region 4b in a region a1 and a region a2 on both sides of the tread surface 2, which is bounded by the tire equator CL. In the gripping region 4a and the gripping region 4b, a plurality of concave stripes 3a and concave stripes 3b are arranged in parallel in a shape that is recessed more toward the inner side of the tire than the contour line of the tread surface 2, respectively, and the concave stripes 3a and concave stripes 3b extend from the tread end TE side in a direction inclined with respect to the tire equator CL. Hereinafter, the shapes of the concave stripes 3a and 3b will be described in detail by taking the concave stripe 3a as a typical example.

As shown in fig. 2A, the concave stripe 3a is recessed inward of the tire along the line of the surface of the tread land 2, compared with the contour O1 of the tread land 2, that is, when the recessed portion is omitted in the tread width direction cross-sectional view. The recessed shape is not particularly limited, and in the illustrated example, the recessed shape is a curved recessed shape from the contour line O1, and a plurality of recessed strips 3a are arranged in parallel to form a wave shape.

In fig. 1 (a), the concave stripe 3a is illustrated with a solid line to show an extended shape.

The cross-sectional shape of the concave stripe 3a is not limited to the example shown in fig. 2A, and can be appropriately modified to a shape opened in a rectangular shape from the contour O1, for example, as shown in fig. 2B.

When the player directly touches the grip area 4a of the tire 1 with a hand during a wheelchair strike-out for a race, a brake, or the like, the plurality of concave strips 3a arranged in the grip area 4a come into contact with the hand. When the plurality of concave stripes 3a are in contact with the surface of the hand, friction is generated between the concave stripes 3a and the hand, and gripping performance can be exhibited. At this time, since the concave stripe 3a has a shape recessed from the contour line O1 of the tread surface 2, the surfaces of the hand and the finger are not pressed against each other by the component protruding from the contour line O1 of the tread surface 2 and strongly abut against each other, and the grip performance can be improved without damaging the hand of the player.

Here, the concave stripe 3a has a point that it extends in a direction inclined with respect to the tire equator CL. That is, in the sport of tennis or the like, the forward and backward movements are centered particularly in the forward and backward direction, and the hand input direction is also the forward and backward direction. Therefore, by forming the concave stripes 3a in a direction crossing the front-rear direction, i.e., in a direction inclined with respect to the tire equator CL, the gripping force between the tire 1 and the hand can be exerted.

The inclination angle of the concave stripes 3a with respect to the tire equator CL is not particularly limited, but the acute angle θ 1 formed by the concave stripes 3a and the tire equator CL is preferably 30 ° or more. By setting the acute angle θ 1 to 30 ° or more, it is possible to exhibit higher gripping performance with respect to a hand that performs a forward-backward movement. The concave strips 3a may extend in a direction orthogonal to the tire equator CL.

The acute angle θ 2 between the concave strip 3b and the tire equator CL is preferably the same as the acute angle θ 1, but may be a different angle. Further, the concave strips 3b may extend in a direction orthogonal to the tire equator CL. Further, the concave strips 3a and the concave strips 3b may extend in a direction axially symmetrical with respect to the tire equator CL with the tire equator CL as a symmetry axis.

The concave stripe 3a starts from the tread end TE side, that is, the region adjacent to the tread end TE. The player mainly touches the area adjacent to the tread end TE when directly touching the tire 1 with his hand. That is, the player performs the following operations during the rowing and braking of the wheelchair: the tire 1 is rotated by touching an area adjacent to the tread end TE on the side close to the body of the player with a hand. Therefore, by disposing the concave stripe 3a in the region adjacent to the tread end TE, the grip between the hand and the tread ground 2 can be improved.

The concave stripe 3a preferably has a start end at a position 7.0% to 33.0% of the width-direction length WD of the tread land 2 along the outer edge from the tread end TE, and more preferably, the start end is located at the tread end TE. This is because, in particular, a region where the hand of the player has a strong input tends to be located here.

The tread width direction length W1 along the outer edge of the tread land 2 in the grip region 4a in which the concave stripes 3a are arranged is preferably 7.0% to 33.0% of the width direction length WD of the tread land 2. By setting the ratio W1/WD to 7.0% or more, the grip with the hands of the player can be sufficiently improved, and by setting the ratio W1/WD to 33.0% or less, the rigidity of the surface of the tread ground 2 can be maintained.

The tire 1 is provided with a grip region 4a in which concave stripes 3a are arranged over the entire circumference of the tread surface 2, so that a high grip can be obtained regardless of which portion of the tire circumferential direction the player's hand contacts during rolling.

The depth d1 of the concave stripe 3a is not particularly limited, but is preferably 0.5mm to 2.0 mm. By setting the depth d1 to 0.5mm or more, the grip with the hand can be sufficiently improved, and by setting the depth d1 to 2.0mm or less, the rigidity of the tread surface 2 can be maintained.

The opening width w10 of the concave stripe 3a is not particularly limited, but is preferably 0.5mm to 2.0 mm. Here, the opening width w10 of the concave stripe 3a is an opening length orthogonal to the extending direction of the concave stripe 3a on the contour line O1. By setting the opening width w10 to 0.5mm or more, the grip with the hand can be further improved, and by setting the opening width w10 to 2.0mm or less, the rigidity of the tread surface 2 can be maintained, and it is possible to prevent foreign matter such as sand from entering the inside of the concave strip 3a to damage the inside of the concave strip 3a, or to prevent the hand of the player from being injured by the entered foreign matter.

The interval between the concave stripes 3a is preferably 0mm to 3.0 mm. Here, the arrangement interval means the shortest distance between the adjacent concave stripes 3 a. In the example shown in fig. 2A, the concave stripes 3a are arranged without an interval, that is, with an arrangement interval of 0 mm. As shown in fig. 2B, when the side wall of the concave strip 3a extends in the tire radial direction, the concave strip 3a is preferably arranged with an interval of 0.5mm to 3.0mm in order to prevent the adjacent concave strips 3a from being integrated while sufficiently gripping the hand.

Further, by arranging the grip region 4a and the grip region 4b in the region a1 and the region a2 on both sides of the tire equator CL, grip between the tire 1 and the hand can be improved regardless of the mounting direction of the tire. That is, as described above, the player performs the following operations during the rowing and braking of the wheelchair: the tire 1 is rotated by touching an area adjacent to the tread end TE on the side close to the body of the player with a hand. The side close to the body of the player is determined according to the mounting direction of the tire, but the grip with the hand can be exerted regardless of the direction in which the tire is mounted. In general, tires for wheelchair for sports are mounted in a negative camber manner in order to facilitate turning operation. In such a mounting pattern, one of the region a1 and the region a2 is mainly in contact with the ground plane, and wear preferentially occurs in a region on the side in contact with the ground plane. When one of the region a1 and the region a2 is worn, the tire 1 is often replaced and used so that the mounting direction thereof is reversed. Therefore, by providing the grip region 4a or the grip region 4b in both the region a1 and the region a2, the grip performance can be exhibited before and after the replacement.

Next, the tire 1 includes the recessed portions 5a and the recessed portions 5b in the region a1 and the region a2, respectively, and the recessed portions 5a and the recessed portions 5b are defined by two lines extending radially from one point on the grip region 4a or the grip region 4b side with respect to the tire equator CL toward the grip region 4a or the grip region 4b, and a line connecting the tips of the two lines to each other.

Fig. 3A shows the recess 5a of fig. 1 in an enlarged manner. The shapes of the concave portions 5a and 5b will be described by taking the concave portion 5a as a typical example. In the region a1, the two lines L1 and L2 each extend from a point E1 on the side of the grip region 4a with respect to the tire equator CL in a radially curved manner toward the grip region 4 a. The distal end E2 of the line L1 on the side of the grip region 4a and the distal end E3 of the line L2 on the side of the grip region 4a are connected to each other by a curved line L3, and the concave portion 5a is formed by the line L1, the line L2, and the line L3. The concave portion 5a has a shape that is opened from the point E1 toward the grasping area 4a side by including two radially extending lines.

According to the above configuration, high drainage can be provided to the tire 1. In other words, particularly when playing tennis, the straight-forward movement and the backward movement of the wheelchair for sports are centered. At this time, the tread surface 2 is in contact with the ground surface centering on the tire equator CL and the region adjacent to the tire equator CL. When the tread surface 2 comes into contact with a wet ground contact surface, moisture on the ground contact surface is sucked into the recess 5a from the tire equator CL side and is discharged to the tread end TE side along the radial shape as the tire 1 rotates. This improves drainage and prevents slippage of the tire 1. The recessed portion 5a has a shape that is axisymmetric with respect to the symmetry axis s1, with a line segment along the tread width direction from the point E1 as the symmetry axis s 1. The shape of the tire is axisymmetric with respect to the symmetry axis s1 along the tread width direction, so that the moisture discharge from the tire equator CL side to the tread end TE side is facilitated.

Further, the distance r1 in the tread width direction between the tire equator CL and the point E1 of the recessed portion 5a is preferably such that the point E1 of the recessed portion 5a is located at a position 5% to 15% of the width direction length WD of the tread land 2 along the outer edge from the tire equator CL in the tread width direction. As described above, since the contact pressure with the ground contact surface tends to increase in the region centered on the tire equator CL, particularly during the forward movement and the backward movement, the water discharge performance can be more efficiently improved by disposing the concave portion 5a in such a range.

The maximum length w1 of the recessed portion 5a in the width direction along the outer edge of the tread land 2 is preferably 7.0% to 33.0% of the width direction length WD of the tread land 2. By setting the ratio w1/WD to 7.0% or more, moisture in the ground contact surface can be sufficiently absorbed, and by setting the ratio w1/WD to 33.0% or less, the tread surface 2 can sufficiently grip the ground contact surface.

More specifically, the maximum length w1 in the width direction of the recess 5a is preferably 1.0mm to 5.0 mm. The maximum width length w1 is set to 1.0mm or more, whereby moisture on the ground contact surface can be sufficiently sucked in, and the maximum width length w1 is set to 5.0mm or less, whereby the tread surface 2 can sufficiently grip the ground contact surface.

The maximum length h1 of the recessed portion 5a in the tread circumferential direction is preferably 1.0mm to 10.0 mm. The maximum length h1 in the tread circumferential direction is set to 1.0mm or more, and moisture in the contact surface can be sufficiently absorbed, and the maximum length h1 in the tread circumferential direction is set to 10.0mm or less, and the tread surface 2 can sufficiently grip the contact surface.

The inclination angle θ 3 and the inclination angle θ 4, which are acute angles formed by the line segment t1 of the connection point E1 and the tip end E2 and the line segment t2 of the connection point E1 and the tip end E3 of the concave portion 5a and the symmetry axis s1, are preferably 20 ° to 70 °. By setting the inclination angle θ 3 and the inclination angle θ 4 within the above range, the drainage action from the tire equator CL side toward the tread end TE side can be promoted.

The inclination angle θ 3 and the inclination angle θ 4 are preferably the same angle, but may be different angles.

Fig. 4A is a sectional view taken along a line t1 of fig. 3A. The shape of the concave portion 5a in the tire radial direction is not particularly limited, but it is preferable that the depth in the tire radial direction gradually decreases from the point E1 toward the apex E2 to efficiently drain water from the tire equator CL side toward the tread end TE side. As shown in fig. 4B, the concave portion 5a may extend with a constant tire radial depth from the tire equator CL side to the tread end TE side, or may have a variable depth.

The maximum depth d2 in the tire radial direction of the recessed portion 5a is preferably 0.5mm to 2.0 mm. By setting the maximum depth d2 of the recessed portion 5a to 0.5mm or more, moisture on the ground contact surface can be sufficiently sucked into the recessed portion 5a, and by setting the maximum depth d2 of the recessed portion 5a to 2.0mm or less, the durability and rigidity of the surface of the tread on the ground 2 can be maintained.

The recesses 5a are preferably arranged at equal intervals over the entire circumference of the tread surface 2. More preferably, 80 to 320 are arranged over the entire circumference of the tread surface 2. By arranging 40 or more in the region on the side bounded by the tire equator CL at equal intervals, the drainage can be further improved, and by setting 160 or less, the rigidity of the tread surface 2 can be maintained.

The concave portion 5a is not limited to the example shown in fig. 1 and 3A, and can be appropriately modified into a shape shown in fig. 3B to 3E, for example. The recessed portion 5c in fig. 3B is a triangular shape defined by two sides L4 and L5 extending radially from the point E10 toward the grip region 4a and a side L6 connecting the tips of the two sides to each other, and is axisymmetric with respect to a line segment s1 extending from the point E10 in the tread width direction. The recessed portion 5d illustrated in fig. 3C is a triangular shape defined by a side L7 extending from the point E20 toward the grip region 4a in a direction inclined with respect to the tread width direction, a side L8 extending from the point E20 toward the grip region 4a in the tread width direction, and a side L9 connecting the side L7 and the side L8 to each other. The concave portion 5E illustrated in fig. 3D is a semicircular shape defined by curved arc-shaped curves L10 and L11 extending radially from the point E30 toward the grip region 4a and a line segment L12 connecting the curve L10 and the curve L11 to each other. The concave portion 5f illustrated in fig. 3E has a crescent shape defined by arc-shaped curves L13 and L14 extending radially from the point E40 toward the grip region 4a and an arc-shaped curve L15 connecting the curve L13 and the curve L14 to each other.

Further, it is preferable that both of the region a1 and the region a2 have a substantially smooth surface shape having no unevenness other than the dimples 5a on the tire equator CL side than the gripping region 4a and the gripping region 4 b. According to the above configuration, the grip with the ground plane can be improved when the ground plane is dry. The recessed portions 5a and 5b can also function as wear indicators for grasping the wear state of the tire 1.

Further, the recessed portions 5a and 5b are preferably arranged with a phase difference along the tire equator CL between the region a1 and the region a 2. In the present specification, for example, the component X and the component Y "are arranged along the tire equator CL with a phase difference" and the component X and the component Y "may be different in position from each other with respect to the tire equator CL". The purpose of this is to prevent variation in the amount of wear in the tread width direction.

(2 nd mode)

Next, a tire 10 according to embodiment 2 of the present invention will be described with reference to fig. 5 and 6. Fig. 5 shows a part of the tread surface 20 of the tire 10 according to embodiment 2 of the present invention spread in the tread width direction, and fig. 6 is an enlarged view of a part of the grip region of fig. 5. In fig. 5 and 6, the same components as those in fig. 1 are denoted by the same reference numerals as those in fig. 1, and descriptions thereof are omitted.

In fig. 5, concave stripes 30a and 30b, concave stripes 30c and concave stripes 30d extending in a plurality of directions and intersecting with respect to the tire equator CL, are arranged in the gripping region 40a and the gripping region 40b, respectively. The recessed strips 30a and 30b in the grip area 40a, and the recessed strips 30c and 30d in the grip area 40b follow the shape and size of the recessed strip 3a described above, respectively.

Hereinafter, the grip region 40a and the grip region 40b will be described as a typical example. The concave stripes 30a and the concave stripes 30b extend in a plurality of directions and intersect each other, and a lattice pattern is formed on the tread land 2. According to the above configuration, in the grip region 40a, the concave stripes can be arranged at a higher density than in the case where the concave stripes are inclined in a single direction with respect to the tire equator CL, and therefore, the grip with the hand can be further improved.

The angle θ 5 formed by the concave bar 30a and the concave bar 30b is arbitrary, but it is preferable that the concave bar 30a and the concave bar 30b are orthogonal to each other at 90 °. If the angle formed by the concave bar 30a and the concave bar 30b is 90 °, an acute angle smaller than 90 ° is not formed in any direction, and therefore, the hand can be prevented from being injured by the corner formed by the concave bar 30a and the concave bar 30 b.

(3 rd mode)

Next, a tire 101 according to embodiment 3 of the present invention will be described with reference to fig. 7. Fig. 7 shows a part of a tread surface 201 of a tire 101 according to embodiment 3 of the present invention spread in a tread width direction. In fig. 7, the same components as those in fig. 1 and 5 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 7, the gripping regions 40a and 40b have a plurality of sipes 6a and 6b, sipes 6c and sipes 6d, respectively, extending in a direction inclined with respect to the tire equator CL. Hereinafter, the grip region 40a will be described as a typical example. In the illustrated example, the sipes 6a and 6b extend from the end of the gripping region 40a on the tread end TE side to the end on the tire equator CL side.

According to the above configuration, the player can be prevented from slipping his hand with respect to the tread surface 201 during sweating during a game. That is, when the player sweats during the course of a game, if a sweat water film exists between the fingers, palm, and tread surface, the grip between the hand and the tread surface is hindered, and the hand slips against the tread surface. Then, in the tread surface 201, since the sipe is provided in the grip region 40a, when the grip region 40a is brought into contact with a wet hand, moisture of sweat is sucked into the sipe 6a and the sipe 6b, and is discharged to the tread end TE side with the rotation of the tire. Thus, the sipes 6a and 6b provide the tire 101 with water drainage, and prevent the hand from slipping with respect to the tread surface 201.

It is preferable that the plurality of sipes 6a and 6b have a plurality of pairs of axisymmetric sipe pairs 60A, and in the axisymmetric sipe pair 60A, a pair of adjacent sipes 6a and 6b are in an axisymmetric relationship with respect to a line segment orthogonal to the tire equator CL, that is, a line segment along the tread width direction as the symmetry axis s 10. In the illustrated example, an axisymmetric sipe pair 60A is formed on the entire circumference of the tread surface 201. Further, in the axially symmetric sipe pair 60A, each of the sipes 6a and 6b is preferably inclined in a direction away from the axis of symmetry s10 from the tire equator CL toward the tread end TE. According to the above configuration, it is possible to more efficiently remove sweat from the tire equator CL side toward the tread end TE side.

The inclination angles θ 6 and θ 7 of each of the sipes 6a and 6b with respect to the symmetry axis s10 are preferably 20 ° to 70 °. According to the above configuration, drainage from the tire equator CL side to the tread end TE side can be promoted.

The opening width w3 of the sipe 6a and the sipe 6b orthogonal to the extending direction is preferably 2.0mm to 8.0 mm. By setting the opening width w3 of the sipe 6a and the sipe 6b to 2.0mm or more, a sufficient water drainage function can be provided, and by setting the opening width w3 of the sipe 6a and the sipe 6b to 8.0mm or less, the rigidity of the tread land 201 can be maintained.

Further, the maximum depth d4 of the sipes 6a and 6b is preferably 0.5mm to 2.0 mm. By setting the maximum depth d4 of the sipe 6a and the sipe 6b to 0.5mm or more, it is possible to impart a sufficient drainage function to the sipe 6a and the sipe 6b, and by setting the maximum depth d4 of the sipe 6a and the sipe 6b to 2.0mm or less, it is possible to maintain the rigidity of the tread surface 201.

Further, as shown in fig. 7, it is preferable that the point E1 of the recessed portion 5a is located on the symmetry axis s10 of the axisymmetric sipe pair 60A. According to this structure, the moisture sucked into the recessed portion 5a flows along the sipes 6a and 6b when being discharged to the tread end TE side with the rotation of the tire, thereby promoting the drainage.

Further, when the point E1 is located on the symmetry axis s10 of the axisymmetric sipe pair 60A, by making the inclination angles θ 6 and θ 7 of the respective sipes 6a and 6b with respect to the symmetry axis s10 coincide with the inclination angles θ 3 and θ 4 of the recessed portion 5a, drainage from the tire equator CL side toward the tread end TE can be further promoted.

Further, the axially symmetric sipe pair 60A is preferably arranged at equal intervals over the entire circumference of the tread surface 201. More preferably, in the region a1, 40 to 160 pairs of axisymmetric sipes 60A are arranged at equal intervals over the entire circumference of the tread land 201. By arranging 40 or more pairs of axisymmetric sipes 60A in a region on one side of the boundary between the tire equator CL, the drainage performance can be further improved, and by setting the pairs of axisymmetric sipes 60A to 160 or less, the rigidity of the tread footprint surface 201 can be maintained.

From the viewpoint of uniformity and uniformity of wear in the tread width direction, the pair of axisymmetric sipes 60A formed in the gripping region 40A and the pair of axisymmetric sipes 60B formed in the gripping region 40B are preferably arranged with a phase difference along the tire equator CL between the region a1 and the region a 2.

(4 th mode)

Next, a tire 102 according to embodiment 4 of the present invention will be described with reference to fig. 8. Fig. 8 shows a part of the tread surface 202 of the tire 102 according to embodiment 4 of the present invention spread in the tread width direction. In fig. 8, the same components as those in fig. 1, 5, and 7 are denoted by the same reference numerals, and the description thereof is omitted.

As shown in fig. 8, a tire 102 includes a widthwise groove 7a and a widthwise groove 7b having a larger opening width than the sipe 6a and the sipe 6b instead of the sipe 6a and the sipe 6b of the tire 101 of embodiment 3. In addition, instead of the sipes 6c and 6d, the gripping region 40b is provided with widthwise grooves 7c and 7 d. The widthwise grooves 7a and 7b extend in the tire widthwise direction like the sipes 6a and 6b, and extend from the end of the gripping region 40a on the tread end TE side to the end on the tire equator CL side. In the illustrated example, the width direction groove 7a and the width direction groove 7b are inclined with respect to the tire width direction.

Hereinafter, unless otherwise specified, the widthwise grooves 7a and 7b may have the same configuration as the sipes 6a and 6 b.

Regarding the widthwise grooves 7a and 7b, when the widthwise grooves 7a are taken as a typical example, the opening width w4 of the widthwise grooves 7a orthogonal to the extending direction is preferably 0.5mm to 5.0 mm. By setting the opening width w4 to 0.5mm or more, sufficient drainage can be provided even in the time of more sweats for athletes such as midsummer, and by setting the opening width w4 to 5.0mm or less, a decrease in rigidity of the tread surface 202 can be suppressed.

The depth d5 of the widthwise groove 7a in the tire radial direction is preferably 0.5mm to 2.0 mm. By setting the depth d5 of the widthwise groove 7a to 0.5mm or more, high drainage can be imparted to the tire 102, and by setting the depth d5 of the widthwise groove 7a to 2.0mm or less, a decrease in rigidity of the tread surface 202 can be suppressed.

Preferably, the width-direction groove 7a and the width-direction groove 7b have a plurality of pairs of axisymmetric width-direction groove pairs 70A, and of the pairs of axisymmetric width-direction grooves 70A, the adjacent pair of width-direction grooves 7a and width-direction grooves 7b are in an axisymmetric relationship with respect to a line segment orthogonal to the tire equator CL, that is, a line segment along the tread width direction as the symmetry axis s 11. The axially symmetric widthwise groove pair 70A can have the same structure as the axially symmetric sipe pair 60A.

Description of the reference numerals

1. 10, 101, 102, tire; 2. 20, 201, 202, tread footprint; 3a, 3b, 3c, 3d, 30a, 30b, concave strips; 4a, 4b, 40a, 40b, a gripping area; 5a, 5b, 5c, 5d, 5e, 5f, a recess; 6a, 6b, 6c, 6d, sipes; 60A, 60B, an axisymmetric sipe pair; 7a, 7b, a width direction groove; 70A, 70B, an axisymmetric widthwise slot pair; CL, tire equator; TE, tread end; a1, a2, region; o1, contour line; e1, E10, E20, E30, E40, dots; t1, t2, line segment; l1, L2, L3, line; l4, L5, L6, edge; l7, L8, L9, edge; l10, L11, curve; l12, line segment; l13, L14, L15, curve; s1, s2, s10, axis of symmetry.