JP2015168302A - pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire having excellent drainage performance while retaining on-snow performance and on-ice performance.SOLUTION: A pneumatic tire 100 includes a plurality of major grooves 1 and 2 which continuously extend in the tire circumferential direction on a tread surface, and partition and form a land part 3. The pneumatic tire is such that: there are included in at least one land part 3, a lateral groove 5 whose one end is opened on one major groove 1 in the major grooves 1 and 2 at both sides, partitioning and forming the land part 3, and extends in the tire width direction, and whose the other end is terminated in the land part 3, a width direction sipe 6a whose one end is opened on one major groove 1, and extends in the tire circumferential direction, and whose the other end is terminated in the land part 3, and a circumferential direction sipe 6b which extends in the tire circumferential direction, and whose both ends are terminated in the land part 3; the other end of the width direction sipe 6a is connected to one end of the circumferential direction sipe 6b; the other end of the lateral groove 5 is connected to the circumferential direction sipe 6b; and the other end of the circumferential direction sipe 6b extends over the connection position with the lateral groove 5 and is terminated in a position extending in the tire circumferential direction.

Description

  The present invention relates to a pneumatic tire.

  Conventionally, pneumatic tires have been proposed that have improved drainage performance while maintaining steering stability on dry road surfaces. In this type of tire, for example, a center sipe that curves and extends from the outer edge of the vehicle outer side between adjacent lateral grooves on the center land portion while gradually decreasing the angle with respect to the tire circumferential direction, and intersects with one lateral groove. A provided pneumatic tire has been proposed (see Patent Document 1).

JP 2013-139166 A

  However, since this sipe has a narrow groove structure, it can be considered that it contributes to the discharge of water, but it cannot be said that the water discharge performance as a whole is sufficient.

  An object of the present invention made in view of such a point is to provide a pneumatic tire with improved drainage performance.

  In order to solve the above-described problem, a pneumatic tire according to the present invention is a pneumatic tire in which a land portion is defined by a plurality of main grooves extending continuously in a tire circumferential direction on a tread surface, and at least one of the above-described pneumatic tires is provided. The land portion has one end that opens into one of the main grooves on both sides that define the land portion and extends in the tire width direction, the other end that terminates in the land portion, and one end that is the one A widthwise sipe that opens in the main groove and extends in the tire width direction, the other end terminates in the land portion, and a circumferential sipe that extends in the tire circumferential direction and both ends terminate in the land portion. The other end of the directional sipe is connected to one end of the circumferential sipe, the other end of the lateral groove is connected to the circumferential sipe, and the other end of the circumferential sipe is connected to the lateral groove. More tire circumference beyond Characterized in that it terminates at a position extending. According to the pneumatic tire of the present invention, drainage performance can be improved.

  In the pneumatic tire of the present invention, it is preferable that the lateral groove is inclined with respect to the tire width direction. According to this configuration, the drainage performance of the tire is further improved.

  In the pneumatic tire of the present invention, it is preferable that the width direction sipe is inclined with respect to the tire width direction. According to this configuration, the drainage performance of the tire is further improved.

  Further, in the pneumatic tire of the present invention, a plurality of sipe coupling bodies formed by coupling the width direction sipe and the circumferential direction sipe are arranged in the tire circumferential direction, and the two sipe couplings adjacent to each other in the tire circumferential direction. The bodies are preferably arranged spaced apart from each other. According to such an arrangement, occurrence of uneven wear of the tire can be suppressed.

  In this specification and claims, “sipe” means a narrow groove having such a groove width that opposing groove wall surfaces come into contact with each other at a tire ground contact portion. In addition, this "tire contact portion" is attached to the applied rim and filled with the specified internal pressure, and comes into contact with the road surface when a load corresponding to the maximum load capacity is applied to the tire stationaryly placed in a vertical posture on the road surface. A tread portion that is a part in the circumferential direction of the tread surface is referred to.

  Further, “extending in the tire width direction” includes not only extending along the tire width direction but also including extending at an angle with respect to the tire width direction.

  Further, “extending in the tire circumferential direction” includes not only extending along the tire circumferential direction but also including extending at an angle with respect to the tire circumferential direction.

  Unless otherwise specified, the sipe shape and the like are measured in a no-load state in which a tire is mounted on an applicable rim and filled with air of a specified internal pressure.

  Here, “applicable rim” is an industrial standard effective in the area where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European Tire and RIM Technical Organization's STANDARDDS MANUAL, TRA (The Tile and Rim Association, Inc.) YEAR BOOK OK, etc. Design Rim).

  The “specified internal pressure” refers to a filling air pressure (maximum air pressure) corresponding to the maximum load capacity of the tire, which is specified according to the tire size, described in the above JATMA YEAR BOOK and the like.

  Further, the air here can be replaced with nitrogen gas or other inert gas.

  According to the present invention, a pneumatic tire with improved drainage performance can be provided.

It is a partial development figure showing a tread pattern of a pneumatic tire concerning one embodiment of the present invention. FIG. 2 is an expanded view of a part of the tread pattern of the pneumatic tire according to the embodiment of the present invention shown in FIG. 1.

  Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a pneumatic tire 100 according to an embodiment of the present invention includes one central main groove 1 that extends in the tire circumferential direction at the center of the tread surface and both sides of the central main groove 1 in the tire width direction. And a side main groove 2 extending in the tire circumferential direction. The central main groove 1 and the two side main grooves 2 define two central land portions 3 and two side land portions 4 on the tread surface. However, the configuration of the main groove and the land portion is not limited to this embodiment, and the main groove and the land portion can be configured by various numbers of main grooves and land portions. Further, in the present embodiment, the central main groove 1 and the side main grooves 2 extend linearly along the tire circumferential direction, but may be configured to extend in a zigzag shape, a wave shape, a crank shape, or the like.

  The central main groove 1 extends continuously in the tire circumferential direction at the tread portion tread center portion including the tire equator C. The central main groove 1 plays a role of efficiently discharging water guided from a central lateral groove 5 and a central sipe connector 6 described later in the circumferential direction of the tire.

  In the illustrated example, the side main grooves 2 are two grooves extending in the tire circumferential direction at positions that are substantially equidistant from the central main groove 1 on both sides in the width direction of the tire. The side main grooves 2 serve to efficiently discharge water guided from side lateral grooves 8 and side sipes 7, 9 described later in the circumferential direction of the tire.

  The “main groove” constituting the present invention is the above-described central main groove 1 and side main groove 2 in the present embodiment.

  The central land portion 3 is an area defined by the central main groove 1 and the side main grooves 2. The central land portion 3 is formed with a central lateral groove 5 extending in the tire width direction, a central sipe connector 6 extending in the tire width direction and the circumferential direction, and a side sipe 7 extending in the tire width direction. Note that the “land portion” constituting the present invention is the central land portion 3 in the present embodiment.

  First, in this embodiment, each element which comprises the central land part 3 is explained in full detail.

  One end of the central lateral groove 5 opens in the central main groove 1 and extends in the tire width direction, and the other end terminates in the central land portion 3. The central lateral groove 5 preferably extends while being inclined in the circumferential direction with respect to the tire width direction, and the inclination angle is more preferably in the range of 20 degrees to 40 degrees. This inclination has an effect of facilitating the flow of water sucked from the central land portion 3 through the central lateral groove 5. In the illustrated example, the central lateral groove 5 terminates at a position slightly closer to the side main groove 2 than the center in the width direction of the central land portion 3. As will be described later, the circumferential sipe 6b constituting the central sipe connector 6 is connected at the end position of the central lateral groove 5 and further ends at a position extending in the tire circumferential direction. The “lateral groove” constituting the present invention is the central lateral groove 5 in the present embodiment.

  As shown in the enlarged view of the tread pattern in FIG. 2, the central sipe connector 6 is configured by connecting a width sipe 6 a extending in the tire width direction and a circumferential sipe 6 b extending in the tire circumferential direction. In the illustrated example, the width-direction sipe 6a and the circumferential-direction sipe 6b are smoothly connected via an arc portion. This configuration improves drainage.

  As shown in FIG. 2, one end of the width direction sipe 6 a opens in the central main groove 1 and extends in the tire width direction, and the other end is connected to one end of the circumferential direction sipe 6 b in the central land portion 3. It ends there. The width direction sipe 6a extends while being inclined in the circumferential direction with respect to the tire width direction. The inclination angle is preferably in the range of 40 degrees to 60 degrees. This inclination has an effect of facilitating the flow of water sucked from the central land portion 3 through the central sipe connector 6. In the present embodiment, the direction in which the width direction sipe 6a is inclined with respect to the tire width direction is substantially the same as the central lateral groove 5. Moreover, in this embodiment, although the inclination angle with respect to the tire width direction of the width direction sipe 6a is larger than the inclination angle that the central lateral groove 5 has, the present invention is not limited thereto, and the inclination angle that the central lateral groove 5 has is more. It can be large.

  One end of the circumferential sipe 6b is connected to the width sipe 6a in the central land portion 3 and ends there. The other end of the circumferential sipe 6b terminates at a position extending beyond the connecting position with the central lateral groove 5 and further extending in the tire circumferential direction. In the present embodiment, the circumferential sipe 6b extends along the tire circumferential direction, but may be slightly inclined in the tire width direction. The inclination angle is preferably within 5 degrees with respect to the tire circumferential direction, for example. Thus, since the front-end | tip of the center horizontal groove 5 is connected with the center sipe connection body 6, more water which entered between the central land part 3 and the road surface is guide | induced to the center side groove 5 from the center sipe connection body 6. be able to. By adopting this configuration, the drainage performance of the pneumatic tire 100 can be improved.

  Further, the end position of the other end of the circumferential sipe 6b is selected such that the central sipe coupling bodies 6 arranged adjacent to each other in the tire circumferential direction are separated and do not overlap. Thus, by arrange | positioning so that the center sipe coupling bodies 6 may not overlap, the rigidity of the center land part 3 can be ensured and generation | occurrence | production of partial wear can be suppressed.

  One end of the side sipe 7 opens into the side main groove 2, and the other end terminates in the central land portion 3. The side sipe 7 extends while being slightly inclined in the circumferential direction with respect to the tire width direction. In the illustrated example, this inclination angle is substantially the same as the inclination angle in the central lateral groove 5, but may be different. Further, the side sipe 7 is disposed at a position further extended from the terminal position on the central land portion 3 of the central lateral groove 5. By this side sipe 7, water on the central land portion 3 can be guided into the sipe, and the drainage performance of the tire is improved.

  Next, in this embodiment, each element which comprises the side land part 4 is explained in full detail.

  The side land portion 4 is an area defined by the side main groove 2 and the tread end TE. The tread end TE referred to here is a tread that comes into contact with the road surface when a tire that is assembled to an applicable rim and filled with air at a specified internal pressure is rolled with a load corresponding to the maximum load capacity applied. This is the end of the portion in the tire width direction. The lateral land portion 4 includes lateral lateral grooves 8 extending in the tire width direction, side sipe 9 extending in the tire width direction, side circumferential sipe 10 extending intermittently in the tire circumferential direction, and in the tire width direction. End lateral grooves 11 extending and end sipes 12, 13 extending in the tire width direction are formed.

  The lateral lateral groove 8 has one end opened in the lateral main groove 2 and extends in the tire width direction, and the other end terminates in the lateral land portion 4. The width of the lateral lateral groove 8 gradually decreases as the distance from the lateral main groove 2 increases. In the present embodiment, the length of the lateral lateral groove 8 is about one fifth of the width of the lateral land portion 4. Further, the lateral lateral grooves 8 extend slightly inclined in the circumferential direction with respect to the tire width direction. This inclination has an effect of facilitating the flow of water sucked into the lateral lateral grooves 8 through the lateral lateral grooves 8. The lateral lateral groove 8 is disposed at a position further extended from the terminal position on the central land portion 3 of the central lateral groove 5. By this lateral lateral groove 8, more water on the lateral land portion 4 can be guided into the groove, and the drainage performance is further improved.

  One end of the side sipe 9 opens into the side main groove 2, and the other end terminates in the side land portion 4. The side sipes 9 extend slightly inclined in the circumferential direction with respect to the tire width direction. Note that this inclination angle is substantially the same as the inclination angle in the central lateral groove 5 in the illustrated example. By this side sipe 9, the water on the side land portion 4 can be guided into the sipe, and the drainage performance is further improved.

  In the illustrated example, the side circumferential sipe 10 is a sipe extending in the tire circumferential direction at a position slightly closer to the side main groove 2 than the tread end TE on the side land portion 4. The lateral circumferential sipe 10 extends along the tire circumferential direction in this example. Moreover, the side circumferential direction sipe 10 smoothly guides the water on the side land portion 4 in the tire circumferential direction, and improves the drainage performance of the tire. And since the side circumferential direction sipe 10 is provided with two or more intermittently in the tire circumferential direction, the side land part 4 is not parted by the side circumferential direction sipe 10. With this configuration, an increase in rolling resistance caused by energy loss due to deformation of the side land portion 4 can be suppressed as compared with a case where the circumferential sipe is continuous in the tread circumferential direction.

  In the illustrated example, the end lateral groove 11 is provided so as to extend from one end of the side circumferential sipe 10 in the tire width direction beyond the tread end TE. In the illustrated example, the end lateral grooves 11 extend in the tire width direction from every other side circumferential sipe 10 arranged in the tire circumferential direction. In the illustrated example, the groove width of the end lateral groove 11 is substantially the same as the groove width of the central lateral groove 5. One end of the end lateral groove 11 is disposed at an intersection position between a straight line further extended from the end position on the central land portion 3 of the central lateral groove 5 and one end of the side circumferential sipe 10. The inclination angle of the end lateral groove 11 with respect to the tire width direction gradually decreases as it approaches the tread end TE. The end lateral groove 11 serves to discharge water guided by the side circumferential sipe 10 from the tread end TE.

  The end sipes 12 and 13 are sipes disposed at substantially equal intervals on both sides in the tire circumferential direction of the end lateral groove 11. One end of each of the end sipes 12 and 13 is located at a position slightly closer to the tread end TE than the center in the tire width direction of the side land portion 4 and is located away from the side circumferential sipe 10. The end sipes 12, 13 extend from the one end beyond the tread end TE in the tire width direction. In particular, the end sipes 12 and 13 are sipes parallel to the end lateral grooves 11. The end sipes 12 and 13 also serve to guide the water on the side land portion 4 into the sipe and to discharge the water from the tread end TE to the outside.

  Although the present invention has been described based on the drawings and embodiments, it should be noted that those skilled in the art can easily make various changes and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications are included in the scope of the present invention. For example, the functions included in each component can be rearranged so as not to be logically contradictory, and a plurality of components can be combined into one or divided. It should be understood that these are included within the scope of the present invention.

1 Central main groove (main groove)
2 Side main groove (main groove)
3 Central land (land)
4 Side land 5 Central lateral groove (horizontal groove)
6 Central sipe connector 6a Width sipe 6b Circumferential sipe 7 Side sipe 8 Side lateral groove 9 Side sipe 10 Side circumferential sipe 11 End lateral groove 12 End sipe 13 End sipe 100 Pneumatic tire

Claims (4)

A pneumatic tire having a land portion defined by a plurality of main grooves extending continuously in a tire circumferential direction on a tread surface,
At least one of the land portions is
A lateral groove that opens in one main groove of the main grooves on both sides that define the land portion and extends in the tire width direction, and the other end terminates in the land portion;
A widthwise sipe having one end opened in the one main groove and extending in the tire width direction, and the other end terminating in the land portion;
A circumferential sipe extending in the tire circumferential direction and having both ends terminating in the land portion,
The other end of the width sipe is connected to one end of the circumferential sipe;
The other end of the lateral groove is connected to the circumferential sipe,
2. The pneumatic tire according to claim 1, wherein the other end of the circumferential sipe terminates at a position extending in the tire circumferential direction beyond the connecting position with the lateral groove.   The pneumatic tire according to claim 1, wherein the lateral groove is inclined with respect to the tire width direction.   The pneumatic tire according to claim 1, wherein the width-direction sipe is inclined with respect to the tire width direction. A plurality of sipe joints formed by connecting the width direction sipe and the circumferential direction sipe are arranged in the tire circumferential direction,
The pneumatic tire according to any one of claims 1 to 3, wherein the two sipe connectors adjacent to each other in the tire circumferential direction are spaced apart from each other.

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