JP2024003372A - tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire which makes it possible to improve pin pull-out resistance without deteriorating road surface damage property.

SOLUTION: In a tire including a hole 13 into which a stud pin 20 is inserted in a tread part 1, a flat part 14 exists around the hole 13, the flat part annularly continuous by coinciding with a profile line L of the tread part 1, and a convex part 15 protruded more than the flat part 14 and a concave part 16 recessed more than the flat part 14 are mixed within an annular region A when the annular region A around which a distance from a center O of the hole 13 is 4 mm-8 mm is regulated around the flat part 14.

SELECTED DRAWING: Figure 3

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a tire having a hole in a tread portion into which a stud pin is inserted, and more particularly to a tire that makes it possible to improve pin removal resistance without worsening road surface damage.

A studded tire has a tread portion with a large number of holes into which stud pins are inserted, and is used with a stud pin inserted into each hole (see, for example, Patent Documents 1 to 4).

Studded tires constructed in this manner belong to the category with the best running performance on ice, and this high performance on ice is, of course, brought about by the stud pins. On the other hand, stud pins are becoming smaller year by year in order to improve road damage resistance, which is regulated by law, and there is concern that the pin removal resistance will be worse than before. Pin removal resistance is related to product life and can be said to be one of the most important issues for studded tires these days.

Patent No. 5406921 Patent No. 6099668 Patent No. 6565574 Patent No. 4488099

An object of the present invention is to provide a tire that can improve pin removal resistance without worsening road surface damage.

To achieve the above object, the tire of the present invention is provided with a hole in the tread portion into which a stud pin is inserted, and a flat portion that extends in an annular manner around the hole in line with the profile line of the tread portion. and when an annular region is defined around the flat part with a distance of 4 mm to 8 mm from the center of the hole, within the annular region there is a convex part that is higher than the flat part and a concave part that is more recessed than the flat part. It is characterized by a mixture of ridges and depressions.

In the present invention, in a tire having a hole in the tread portion into which a stud pin is inserted, there is a flat portion surrounding the hole that is continuous in an annular manner and coincides with the profile line of the tread portion, so that the stud pin can be stably held. can do. Then, when an annular area is defined around the flat part with a distance of 4 mm to 8 mm from the center of the hole, within the annular area there are a convex part that is higher than the flat part and a recess that is more depressed than the flat part. Since the stud pins are mixed together, when the stud pin falls down, the force applied in the direction of the fall can be dispersed based on the presence of the recess, and the stud pin can be prevented from falling off. At that time, if the rigidity is extremely reduced due to the presence of the recess, the stud pin may easily fall down and the pin removal resistance may deteriorate, but the presence of the convex part along with the recess within the annular area compensates for the rigidity. I can do it. Therefore, the existence of both the convex portion and the concave portion within the annular region can effectively improve the pin removal resistance. Further, the structure that disperses the force when the stud pin falls down as described above weakens the force with which the stud pin attacks the road surface when driving on a dry road surface, and therefore has the effect of improving road surface damage. Therefore, according to the present invention, pin removal resistance can be improved without worsening road surface damage.

In the present invention, it is preferable that the recesses are arranged on a concentric circle centered on the hole, and that the recess has a shape that is intermittent in a part of the circumferential direction of the concentric circle. If the recesses are continuous in the circumferential direction of a concentric circle centered on the hole, the stud pin will tend to fall down due to lack of rigidity, which is disadvantageous in terms of pin removal resistance. By having such a shape, it is possible to ensure rigidity around the stud pin and prevent the stud pin from falling off.

It is preferable that the recessed portion is disposed at a position that does not overlap with a circumferential line that passes through the center of the hole and is parallel to the tire circumferential direction. This prevents the stud pin from falling down excessively during sudden acceleration and sudden deceleration, and effectively prevents the stud pin from falling off.

It is preferable that the recessed portion is disposed at a position that does not overlap with a width direction line that passes through the center of the hole and is perpendicular to the tire circumferential direction. As a result, when the vehicle makes a sharp turn, the stud pin is prevented from falling down excessively, and it is possible to effectively prevent the stud pin from falling off.

When an inner annular region whose distance from the center of the hole is 4 mm to 6 mm and an outer annular region whose distance from the center of the hole is 6 mm to 8 mm are defined in the annular region, the area of the recess included in the inner annular region is preferably larger than the area of the recess included in the outer annular region. This effectively disperses the force generated when a strong force is applied to the stud pin, thereby increasing the effect of improving pin removal resistance.

Preferably, the recesses are arranged on a plurality of concentric circles centered around the hole. Thereby, when the stud pin falls down, the force applied in the direction of the fall can be effectively dispersed, and the stud pin can be prevented from falling off. In this case, the recesses on the plurality of concentric circles are preferably arranged so as to overlap each other in the radial direction of the concentric circles. Thereby, when the stud pin falls down, the force applied in the direction of the fall can be effectively dispersed, and the stud pin can be prevented from falling off, while the effect of improving road surface damage is increased. Alternatively, the recesses on the plurality of concentric circles may be arranged so as not to overlap each other in the radial direction of the concentric circles. As a result, when the stud pin falls down, the force applied in the falling direction can be effectively dispersed, and rigidity can be ensured to prevent the stud pin from falling down excessively, thereby improving pin pull-out resistance. The improvement effect will be greater.

When the body portion of the stud pin inserted into the hole has a longitudinal direction in a plan view of the tread portion, there is an inner annular region whose distance from the center of the hole is 4 mm to 6 mm within the annular region and a distance from the center of the hole. When defining an outer annular region with a diameter of 6 mm to 8 mm, the recess must be located in the inner annular region at a position that does not overlap with an imaginary line that passes through the center of the hole and is parallel to the longitudinal direction of the body part. is preferred. If the distance between the body part of the stud pin and the recessed part is too close, there is a risk that the pin pull-out resistance will deteriorate due to insufficient rigidity. By arranging the recess at a position that does not overlap with the virtual line, the pin removal resistance can be effectively improved.

The depth Hy of the concave portion satisfies the relationship of 0.05Hs≦Hy≦0.25Hs with respect to the height Hs of the stud pin, and the height Hx of the convex portion satisfies the relationship 0.10Hy≦Hx with respect to the depth Hy of the concave portion. It is preferable to satisfy the relationship ≦0.80Hy. Thereby, the pin removal resistance can be effectively improved.

The tire of the present invention is preferably a pneumatic tire, but may be a non-pneumatic tire. In the case of a pneumatic tire, its interior can be filled with air, an inert gas such as nitrogen, or other gas.

1 is a meridian cross-sectional view showing a pneumatic tire according to an embodiment of the present invention. FIG. 2 is a sectional view showing a stud pin installation portion in the tread portion of the pneumatic tire shown in FIG. 1. FIG. FIG. 2 is a plan view showing a stud pin installation portion in the tread portion of the pneumatic tire shown in FIG. 1. FIG. It is a perspective view showing an example of a stud pin. FIG. 5 is a plan view showing the stud pin of FIG. 4; FIG. 5 is a side view showing the stud pin of FIG. 4; FIG. 5 is a sectional view showing a state in which the stud pin of FIG. 4 is inserted into a hole in a tread portion. (a) to (c) are plan views showing modified examples of the stud pin installation portion, respectively. (a) to (d) are plan views showing other modifications of the stud pin installation portion, respectively. It is a top view which shows the other modification of a stud pin installation part. (a) to (e) are plan views showing still other modifications of the stud pin installation portion, respectively. It is a top view which shows the other modification of a stud pin installation part.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a pneumatic tire according to an embodiment of the present invention, FIGS. 2 and 3 show the stud pin installation part in the tread part, FIGS. 4 to 6 show examples of stud pins, and FIG. 7 shows the stud pin installation part in the tread part. This shows a state in which the pin is inserted into the hole in the tread portion.

As shown in FIG. 1, the pneumatic tire of this embodiment includes a tread portion 1 extending in the tire circumferential direction and forming an annular shape, and a pair of sidewall portions 2, 2 disposed on both sides of the tread portion 1. and a pair of bead portions 3, 3 disposed on the inner side of the sidewall portions 2 in the tire radial direction.

A carcass layer 4 is mounted between the pair of bead portions 3, 3. This carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction, and is folded back from the inside of the tire to the outside around bead cores 5 arranged in each bead portion 3. A bead filler 6 made of a rubber composition and having a triangular cross section is arranged on the outer periphery of the bead core 5.

On the other hand, a plurality of belt layers 7 are embedded in the outer peripheral side of the carcass layer 4 in the tread portion 1 . These belt layers 7 include a plurality of reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to cross each other between layers. In the belt layer 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set, for example, in the range of 10° to 40°. As the reinforcing cord for the belt layer 7, a steel cord is preferably used. At least one belt cover layer 8 made of reinforcing cords arranged at an angle of, for example, 5° or less with respect to the circumferential direction of the tire is disposed on the outer circumferential side of the belt layer 7 for the purpose of improving high-speed durability. There is. As the reinforcing cord for the belt cover layer 8, organic fiber cords such as nylon and aramid are preferably used.

Note that the tire internal structure described above is a typical example of a pneumatic tire, but is not limited thereto. Furthermore, the tread pattern formed on the tread portion 1 is not particularly limited either.

In the pneumatic tire described above, circumferential grooves 11 extending in the circumferential direction of the tire are formed in the tread portion 1, and a plurality of land portions 12 are defined by these circumferential grooves 11. These land portions 12 are divided into a large number of blocks by, for example, lateral grooves (not shown) extending in the width direction of the tire. A plurality of holes 13 into which stud pins 20 are inserted are formed in the land portion 12 of the tread portion 1 . As shown in FIGS. 4 to 6, the stud pin 20 includes a columnar body portion 21, a tip portion 22 disposed on the distal end side of the body portion 21, and a tip portion 22 disposed on the proximal end side of the body portion 21. It is composed of a flange portion 23. The tip portion 22 is made of a material that is harder than the body portion 21. The flange portion 23 has a larger outer diameter than the body portion 21. The stud pin 20 is arranged in the tread part 1 so that the body part 21 and the flange part 23 are inserted into the hole 13, while the tip part 21 protrudes from the profile line L of the tread part 1 (see FIG. 7). . Since the inner diameter of the hole 13 is slightly smaller than the outer diameter of the body portion 21 of the stud pin 20, the stud pin 20 inserted into the hole 13 is firmly held against the tread portion 1.

In a tire having holes 13 into which stud pins 20 are inserted in the tread portion 1, as shown in FIGS. There is a flat portion 14 having an annular shape. The profile line L of the tread portion 1 is a circular arc that forms the outline of the tread portion 1 in a meridian section of the tire. 2 and 3, there is a portion around the hole 13 that is slightly shallower than the profile line L for design reasons, but this portion is not necessarily necessary.

In FIG. 3, a virtual circle C1 where the distance X1 from the center O of the hole 13 is 4 mm, a virtual circle C2 where the distance X2 from the center O of the hole 13 is 6 mm, and a distance X3 from the center O of the hole 13 are A virtual circle C3 having a diameter of 8 mm is depicted. Here, an annular region A is defined around the flat portion 14, the distance from the center O of the hole 13 being 4 mm to 8 mm. The annular area A is an area sandwiched between the virtual circle C1 and the virtual circle C3. The annular region A is composed of an inner annular region Ai whose distance from the center O of the hole 13 is 4 mm to 6 mm and an outer annular region Ao whose distance from the center O of the hole 13 is 6 mm to 8 mm. At this time, within the annular region A, there are a plurality of convex portions 15 that are raised toward the outer side in the tire radial direction than the flat portion 14 and a plurality of recessed portions 16 that are depressed toward the tire radial direction inward than the flat portion 14. These convex portions 15 and concave portions 16 are mixed in the annular region A. In FIG. 3 and subsequent drawings, the recess 16 is shaded for ease of understanding.

As described above, in the tire including the hole 13 in the tread portion 1 into which the stud pin 20 is inserted, there is a flat portion 14 around the hole 13 that is continuous in an annular manner and coincides with the profile line L of the tread portion 1. Therefore, as shown in FIG. 7, in a state where the stud pin 20 is inserted into the hole 13 of the tread portion 1, the stud pin 20 can be stably held. Moreover, when an annular area A is defined around the flat part 14 with a distance of 4 mm to 8 mm from the center O of the hole 13, within the annular area A there is a convex part 15 that is higher than the flat part 14 and a flat part 14. Since there are concave portions 16 that are more concave, when the stud pin 20 falls down, the force applied in the direction of the fall is dispersed based on the presence of the concave portions 16, thereby preventing the stud pin 20 from falling off. can. At this time, if the rigidity is extremely reduced due to the presence of the recess 16, the stud pin 20 may easily fall down and the pin removal resistance may deteriorate. Rigidity can be supplemented. Therefore, the existence of both the convex portion 15 and the concave portion 16 within the annular region A can effectively improve the pin removal resistance. Furthermore, the structure that disperses the force when the stud pin 20 collapses as described above weakens the force with which the stud pin 20 attacks the road surface when driving on a dry road surface, and therefore has the effect of improving road surface damage. Thereby, the pin removal resistance can be improved without worsening the road surface damage property.

In order to optimize the buffering effect of the recess 16, the maximum width of the recess 16 measured in the radial direction from the center O of the hole 13 is preferably 0.5 mm or more and less than 2 mm. Furthermore, in order to optimize the pin removal resistance, the area ratio of the recess 16 in the annular region A is 10% to 50%, and the area ratio of the convex part 15 in the annular region A is 10% to 90%. The area ratio of the convex portion 15 and the concave portion 16 to the annular region A is preferably less than 90%.

In the above pneumatic tire, as shown in FIG. 3, the recess 16 is arranged on a concentric circle P1 centered on the hole 13, and the recess 16 has an intermittent shape in a part of the circumferential direction of the concentric circle P1. . In FIG. 3, a plurality of convex portions 15 and a plurality of concave portions 16 are alternately arranged at intervals on a concentric circle P1. Further, a plurality of convex portions 15 are arranged at intervals on a concentric circle P2 set outside the concentric circle P1 with the hole 13 as the center. If the recess 16 is continuous in the circumferential direction of the concentric circle P1 centered on the hole 13, the stud pin 20 tends to fall down due to insufficient rigidity, which is disadvantageous in terms of pin removal resistance. However, since the recess 16 has an intermittent shape in a part of the circumferential direction of the concentric circle P1, rigidity around the stud pin 20 can be ensured and the stud pin 20 can be prevented from falling off.

FIGS. 8(a) to 8(c) each show a modification of the stud pin installation portion. In FIG. 8(a), the convex portion 15 is disposed on a concentric circle P2 and has a continuous shape in the circumferential direction of the concentric circle P2, and the concave portion 16 is disposed on the concentric circle P1 and has a shape continuous in the circumferential direction of the concentric circle P1. It has a continuous shape. In FIG. 8(b), the convex portion 15 is disposed on a concentric circle P2 and has a continuous shape in the circumferential direction of the concentric circle P2, and the concave portion 16 is disposed on the concentric circle P1 and has a shape continuous in the circumferential direction of the concentric circle P1. It has an intermittent shape in some parts. In FIG. 8(c), the convex portion 15 is disposed on a concentric circle P2 and has a continuous shape in the circumferential direction of the concentric circle P2, and the concave portion 16 is disposed on a concentric circle P1 and has a circular shape in plan view. have. In this way, the shape and arrangement of the convex portions 15 and concave portions 16 can be changed depending on the required performance and design.

FIGS. 9(a) to 9(d) each show other modifications of the stud pin installation portion. In the embodiment shown in FIG. 1 described above, the convex portion 15 and the concave portion 16 are arranged symmetrically on the concentric circles P1 and P2. In contrast, in FIGS. 9(a) to 9(c), the convex portion 15 and the concave portion 16 are asymmetrically arranged on the concentric circle P1. Moreover, in FIG. 9(d), a part of the convex portion 15 is linear.

FIG. 10 shows still another modification of the stud pin installation portion. In FIG. 10, the recessed portion 16 is disposed at a position that does not overlap with a circumferential line Lc that passes through the center O of the hole 13 and is parallel to the tire circumferential direction. In this case, during sudden acceleration and sudden deceleration, the stud pin 20 is prevented from falling down excessively, and the stud pin 20 can be effectively prevented from falling off.

Further, in FIG. 10, the recessed portion 16 is disposed at a position that does not overlap the width direction line Lw passing through the center O of the hole 13 and orthogonal to the tire circumferential direction. In this case, when the vehicle makes a sharp turn, the stud pin 20 is prevented from falling down excessively, and the stud pin 20 can be effectively prevented from falling off.

In FIG. 3, an inner annular region Ai whose distance from the center O of the hole 13 is 4 mm to 6 mm and an outer annular region Ao whose distance from the center O of the hole 13 is 6 mm to 8 mm are defined in the annular region A. . The inner annular area Ai is an area sandwiched between virtual circles C1 and C2, and the outer annular area Ao is an area sandwiched between virtual circles C2 and C3. At this time, the area of the recess 16 included in the inner annular region Ai is preferably set larger than the area of the recess 16 included in the outer annular region Ao. By arranging a relatively large number of recesses 16 in the inner annular region Ai in this manner, the force generated when a strong force is applied to the stud pin 20 is effectively dispersed, thereby improving the pin pullout resistance. can be increased.

FIGS. 11(a) to 11(e) each show still other modifications of the stud pin installation portion. In FIGS. 11A to 11E, the recesses 16 are arranged on two of a plurality of concentric circles P1 to P3 centered on the hole 13. In FIGS. That is, in FIG. 11(a), the concave portions 16 that are continuous along the concentric circles P1 and P2 are arranged on the concentric circles P1 and P2, and the convex portions 15 that are continuous along the concentric circle P3 are arranged on the concentric circle P3, The portion between the recesses 16, 16 arranged on the concentric circles P1, P2 is at the height of the profile line L. In FIG. 11(b), concave portions 16 continuous along concentric circles P1 and P3 are arranged on concentric circles P1 and P3, and convex portions 15 continuous along concentric circle P2 are arranged on concentric circle P2. In FIGS. 11(c) and 11(d), concave portions 16 having an intermittent shape are arranged on a part of the circumferential direction of the concentric circles P1 and P2, and convex portions 15 that are continuous along the concentric circle P3 are arranged on the concentric circles P1 and P2. They are arranged on a concentric circle P3. In FIG. 11(e), convex portions 15 and concave portions 16 having an intermittent shape in a part of the circumferential direction of the concentric circles P1 and P2 are arranged alternately on the concentric circles P1 and P2, respectively, and convex portions that are continuous along the concentric circle P3. The portion 15 is arranged on the concentric circle P3. By arranging the recesses 16 on a plurality of concentric circles P1 to P3 centered on the hole 13 in this way, when the stud pin 20 falls down, the force applied in the direction of the fall is effectively dispersed, and the stud pin 20 can be prevented from falling off.

In particular, as shown in FIGS. 11(a) and 11(b), when the recesses 16 on a plurality of concentric circles P1 to P3 are arranged so as to overlap each other in the radial direction of the concentric circles P1 to P3, the stud pin 20 When the vehicle falls down, the force applied in the direction of the fall can be effectively dispersed to prevent the stud pin 20 from falling off, while increasing the effect of improving road surface damage. Further, as shown in FIGS. 11(c) to 11(e), when the recesses 16 on the plurality of concentric circles P1 to P3 are arranged so as not to overlap each other in the radial direction of the concentric circles P1 to P3, the stud pin 20 When the stud pin 20 falls down, the force applied in the direction of the fall can be effectively dispersed, and the rigidity can be ensured to prevent the stud pin 20 from falling down excessively, so the pin removal resistance is greatly improved. Become.

FIG. 12 shows still another modification of the stud pin installation portion. As shown in FIG. 5, the body portion 21 of the stud pin 20 has a dimension D1 in a first direction and a second direction perpendicular to the first direction in a plan view of the tread portion 1 (i.e., a plan view of the stud pin 20). , the dimension D1 is larger than the dimension D2, and the first direction is the longitudinal direction T. In this way, when the body portion 21 of the stud pin 20 has the longitudinal direction T in a plan view of the tread portion 1, the distance from the center O of the hole 13 in the annular region A is 4 mm to 6 mm, as shown in FIG. When defining an inner annular region Ai with a distance of 6 mm to 8 mm from the center O of the hole 13, the recess 16 passes through the center O of the hole 13 within the inner annular region Ai and reaches the body portion 21. It is preferable that it is placed at a position that does not overlap with the imaginary line Tx that is parallel to the longitudinal direction T of. In other words, if the distance between the body part 21 of the stud pin 20 and the recessed part 16 is too short, there is a risk that the pin slipout resistance will deteriorate due to insufficient rigidity. By arranging the recessed portion 16 at a position that does not overlap with the imaginary line Tx parallel to the longitudinal direction T of the portion 21, the pin removal resistance can be effectively improved.

In the above pneumatic tire, the depth Hy of the recess 16 (see FIG. 2) satisfies the relationship of 0.05Hs≦Hy≦0.25Hs with respect to the height Hs of the stud pin 20 (see FIG. 6), and the convex portion 15 (see FIG. 2) preferably satisfies the relationship 0.10Hy≦Hx≦0.80Hy with respect to the depth Hy of the recess 16. Thereby, the pin removal resistance can be effectively improved. If the depth Hy of the concave portion 16 and the height Hx of the convex portion 15 deviate from the above ranges, the effect of improving pin removal resistance will be reduced. For example, when the height Hs of the stud pin 20 is 9 mm to 10 mm, the depth Hy of the recess 16 is in the range of 0.5 mm to 2.0 mm, and the height Hx of the convex part 15 is 0.2 mm to 1.0 mm. can be in the range of

In a pneumatic tire with a tire size of 205/55R16 and a hole in the tread portion into which a stud pin is inserted, the presence or absence of a flat portion formed around the hole, the presence or absence of a recess in an annular region, and the presence or absence of a convexity in an annular region. presence or absence of recesses, presence or absence of intermittent recesses, presence or absence of recesses that overlap with the circumferential line passing through the center of the hole, presence or absence of recesses that overlap with the width direction line that passes through the center of the hole, area of the recess included in the inner annular region, outer annular area. The area of the recess included in the area, the area ratio of the recess in the annular area, the area ratio of the convex part in the annular area, the number of recesses that overlap in the radial direction of concentric circles, the stud pin that passes through the center of the hole in the inner annular area The pneumatic tires of the conventional example, comparative examples 1 to 4, and examples 1 to 9 were manufactured in which the presence or absence of a recess that overlaps with an imaginary line parallel to the longitudinal direction of the body part was set as shown in Tables 1 and 2. did. The stud pin is inserted into the hole so that the longitudinal direction of the body portion is oriented in the width direction of the tire.

These test tires were evaluated for pin removal resistance and road damage resistance using the following test methods, and the results are also shown in Tables 1 and 2.

Pin removal resistance:
Each test tire was assembled onto a wheel with a rim size of 16 x 6.5J and mounted on a front-wheel drive vehicle with a displacement of 1.4L, and the air pressure specified by the vehicle was applied as air pressure, and the test tire was run in the specified city driving mode on an outdoor test course consisting of an asphalt road surface. After driving 20,000km, we measured the number of pins that came out. The evaluation results were expressed as an index using the reciprocal of the measured value and taking the conventional example as 100. The larger the index value, the better the pin removal resistance.

Road surface damage:
Each test tire was assembled onto a wheel with a rim size of 16 x 6.5 J, mounted on a front wheel drive vehicle with a displacement of 1.4 L, and the air pressure was set to 250 kPa. After running twice, the amount of road wear was measured based on the difference in weight between the plates before and after the test. The evaluation results were expressed as an index using the reciprocal of the measured value and taking the conventional example as 100. The larger the index value, the smaller the amount of road surface wear and the better the road surface damage resistance.

As can be seen from Tables 1 and 2, the tires of Examples 1 to 9 had improved road surface damage resistance and pin removal resistance when compared with the conventional example. On the other hand, in the tires of Comparative Examples 1 and 2, although there were concave portions in the annular region, there were no convex portions in the annular region, so that the pin removal resistance was deteriorated due to insufficient rigidity. In the tire of Comparative Example 3, although there were convex portions in the annular region, there were no concave portions in the annular region, and therefore no improvement in pin removal resistance could be obtained. In the tire of Comparative Example 4, the pin removal resistance deteriorated because there was no flat part around the hole.

The present disclosure includes the following inventions.
Invention [1] In a tire having a hole in the tread portion into which a stud pin is inserted, a flat portion is present around the hole and extends in an annular manner in line with the profile line of the tread portion, and around the flat portion When an annular region is defined at a distance of 4 mm to 8 mm from the center of the hole, a convex portion that is more protruding than the flat portion and a recess that is more concave than the flat portion are mixed in the annular region. A tire featuring:
Invention [2] The tire according to Invention [1], wherein the recessed portion is arranged on a concentric circle centered on the hole, and the recessed portion has an intermittent shape in a part of the circumferential direction of the concentric circle.
Invention [3] The tire according to Invention [2], wherein the recessed portion is disposed at a position that does not overlap with a circumferential line that passes through the center of the hole and is parallel to the tire circumferential direction.
Invention [4] The tire according to Invention [2], wherein the recessed portion is disposed at a position that does not overlap with a width direction line that passes through the center of the hole and is orthogonal to the tire circumferential direction.
Invention [5] When an inner annular region whose distance from the center of the hole is 4 mm to 6 mm and an outer annular region whose distance from the center of the hole is 6 mm to 8 mm are defined in the annular region, the inner annular region The tire according to any one of inventions [1] to [4], wherein the area of the recess included in the annular region is larger than the area of the recess included in the outer annular region.
Invention [6] The tire according to any one of Inventions [1] to [5], wherein the recesses are arranged on a plurality of concentric circles centered on the hole.
Invention [7] The tire according to Invention [6], wherein the recesses on the plurality of concentric circles are arranged so as to overlap each other in the radial direction of the concentric circles.
Invention [8] The tire according to Invention [6], wherein the recesses on the plurality of concentric circles are arranged so as not to overlap each other in the radial direction of the concentric circles.
Invention [9] An inner annular region in which the body portion of the stud pin inserted into the hole has a longitudinal direction in plan view of the tread portion, and a distance from the center of the hole is 4 mm to 6 mm within the annular region. and an outer annular region having a distance of 6 mm to 8 mm from the center of the hole, the recess passes through the center of the hole in the inner annular region and is parallel to the longitudinal direction of the body part. The tire according to any one of inventions [1] to [8], characterized in that the tire is arranged at a position that does not overlap with an imaginary line.
Invention [10] The depth Hy of the concave portion satisfies the relationship 0.05Hs≦Hy≦0.25Hs with respect to the height Hs of the stud pin, and the height Hx of the convex portion is the depth Hy of the concave portion. The tire according to any one of inventions [1] to [9], characterized in that the tire satisfies the relationship: 0.10Hy≦Hx≦0.80Hy.

1 Tread portion 2 Sidewall portion 3 Bead portion 4 Carcass layer 5 Bead core 6 Bead filler 7 Belt layer 8 Belt cover layer 11 Circumferential groove 12 Land portion 13 Hole 14 Flat portion 15 Convex portion 16 Recess portion 20 Stud pin 21 Body portion 22 Chip Part 23 Flange part

Claims (10)

In a tire having a hole in the tread portion into which a stud pin is inserted, there is a flat portion around the hole that is continuous in an annular manner and coincides with the profile line of the tread portion, and the center of the hole is located around the flat portion. When an annular region is defined at a distance of 4 mm to 8 mm from tire. The tire according to claim 1, wherein the recessed portion is arranged on a concentric circle centered on the hole, and the recessed portion has an intermittent shape in a part of the circumferential direction of the concentric circle. 3. The tire according to claim 2, wherein the recess is disposed at a position that does not overlap with a circumferential line that passes through the center of the hole and is parallel to the tire circumferential direction. 3. The tire according to claim 2, wherein the recess is disposed at a position that does not overlap with a widthwise line passing through the center of the hole and perpendicular to the tire circumferential direction. When an inner annular region whose distance from the center of the hole is 4 mm to 6 mm and an outer annular region whose distance from the center of the hole is 6 mm to 8 mm are defined in the annular region, the inner annular region includes 5. The tire according to claim 1, wherein the area of the recess included in the outer annular region is larger than the area of the recess included in the outer annular region. The tire according to any one of claims 1 to 4, wherein the recesses are arranged on a plurality of concentric circles centered on the hole. The tire according to claim 6, wherein the recesses on the plurality of concentric circles are arranged so as to overlap each other in the radial direction of the concentric circles. The tire according to claim 6, wherein the recesses on the plurality of concentric circles are arranged so as not to overlap each other in the radial direction of the concentric circles. The body portion of the stud pin inserted into the hole has a longitudinal direction in a plan view of the tread portion, and there is an inner annular region within the annular region having a distance of 4 mm to 6 mm from the center of the hole; When defining an outer annular region having a distance from the center of 6 mm to 8 mm, the recess is defined within the inner annular region by an imaginary line passing through the center of the hole and parallel to the longitudinal direction of the body part. The tire according to any one of claims 1 to 4, characterized in that the tires are arranged in non-overlapping positions. The depth Hy of the concave portion satisfies the relationship 0.05Hs≦Hy≦0.25Hs with respect to the height Hs of the stud pin, and the height Hx of the convex portion is 0 with respect to the depth Hy of the concave portion. The tire according to any one of claims 1 to 4, characterized in that the tire satisfies the relationship: .10Hy≦Hx≦0.80Hy.

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