JP5766515B2 - tire - Google Patents

Description

  The present invention relates to a tire in which a plurality of linear circumferential sipes extending in the tire circumferential direction are formed on a land portion.

  Conventionally, pneumatic tires mounted on passenger cars and the like are various in order to achieve both the maneuverability and stability (hereinafter referred to as “steering stability”) of vehicles equipped with pneumatic tires and the drainage performance on wet road surfaces. Tread patterns have been proposed.

  For example, a pneumatic tire in which an inclined groove extending from the vicinity of the tire equator line to the tread shoulder end and a circumferential groove extending in the tire circumferential direction while intersecting the inclined groove is known (for example, a patent) Reference 1). According to such a pneumatic tire, drainage due to the inclined grooves is sufficiently ensured, and drainage is ensured also in the circumferential grooves, so that the drainage is improved as a whole.

  Further, in the pneumatic tire described above, the groove depth of the circumferential groove is set to be shallower than the groove depth of the inclined groove, and the buckling of the block end that tends to occur along the circumferential groove is suppressed. Stability is also improved.

JP 2000-272308 A (FIG. 1)

  By the way, in recent years, an electric vehicle or a hybrid type vehicle in which an internal combustion engine and an electric motor are used together has extremely high torque in a low rotation range as compared with a conventional vehicle using an internal combustion engine as a power source. It has the feature of generating a high driving force from the start.

  For this reason, in a pneumatic tire with a complicated tread pattern, the land block defined by the groove is easily damaged by wear, and the complicated tread widely used in pneumatic tires for automobiles that use an internal combustion engine as a power source. Patterns tend to be avoided in electric and hybrid vehicles.

  However, in order to suppress such wear of the land block, if the land block has a simple shape, it may cause another problem that drainage performance and steering stability are deteriorated.

  Therefore, the present invention has been made in view of such a situation, and even when the torque in a low rotation range is high, such as an electric vehicle or a hybrid vehicle, sufficient drainage performance and driving stability are ensured. The purpose is to provide tires.

The present invention is characterized by a linear circumferential sipe (circumferential sipe 130, 140, which includes a land portion (rib-shaped land portion 40) that contacts the road surface and extends along the tire circumferential direction (tire circumferential direction D _C ). 150) is a plurality of tires (for example, pneumatic tires 10A) formed in the land portion, and the length of the circumferential sipe (length L1A) is a road surface in a state where a normal load is applied to the tires. It is longer than the contact length (contact length L _R ), and a part of the circumferential sipe in the tire circumferential direction is formed so as to overlap with another circumferential sipe in the tread width direction.

  In the above-described feature of the present invention, an end portion (end portion 131A) of the circumferential sipe in the tire circumferential direction may be terminated in the land portion.

  In the above-described feature of the present invention, the land portion has a recessed portion (recessed portion 200) extending from the tire equator line (tire equator line CL) side toward the tread shoulder (tread shoulder 30) and recessed from the land portion. It may be formed.

  In the above-described feature of the present invention, the concave portion is V-shaped in a tread surface view, and a plurality of the concave portions may be formed in the tire circumferential direction.

  In the above-described feature of the present invention, the circumferential sipe may extend to the recess.

  In the above-described feature of the present invention, the recess is formed with a plurality of ridges (the ridges 210) protruding from the bottom portion (bottom portion 205) of the recess, and the ridges are formed in the tread width direction in the circumferential direction. It may be formed at a position different from the direction sipe.

  According to the features of the present invention, it is possible to provide a tire that ensures sufficient drainage and steering stability even when the torque in a low rotation range is high, such as an electric vehicle or a hybrid vehicle.

1 is a schematic perspective view of a pneumatic tire 10 according to an embodiment of the present invention. 1 is a partially enlarged perspective view of a tread portion of a pneumatic tire 10 according to an embodiment of the present invention. It is sectional drawing of the recessed part 200 along the F3-F3 line | wire shown in FIG. FIG. 3 is a cross-sectional view of a recess 200 taken along line F4-F4 shown in FIG. It is an expansion perspective view of the recessed part 200 which concerns on embodiment of this invention. FIG. 6 is a partial plan view of a tread portion of a pneumatic tire 10A according to a modified example of the present invention.

  Next, an embodiment of a tire (pneumatic tire) according to the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

  Accordingly, specific dimensions and the like should be determined in consideration of the following description. Moreover, the part from which the relationship and ratio of a mutual dimension differ also in between drawings may be contained.

(1) Overall Schematic Configuration of Tire FIG. 1 is a schematic perspective view of a pneumatic tire 10 according to this embodiment. As shown in FIG. 1, the pneumatic tire 10 includes a V-shaped land portion 20 in a tread surface view. The pneumatic tire 10 may be filled with an inert gas such as nitrogen gas instead of air.

Land portion 20 is a portion to come in contact with a road surface, is formed with a plurality in the tire circumferential direction D _C. Between the land portions 20 adjacent in the tire circumferential direction D _C, recesses 200 are formed. Recess 200 is also a similarly V-shaped and the land portion 20, is formed with a plurality in the tire circumferential direction D _C.

A plurality of circumferential sipes 110 and a plurality of circumferential sipes 120 are formed in the land portion 20. Circumferential sipe 110, 120 is a linear thin groove extending along the tire circumferential direction D _C. The groove width along the tread width direction _DT of the circumferential sipes 110 and 120 is preferably 0.4 mm or more and 2.0 mm or less.

A plurality of circumferential sipes 110 are formed on one side (for example, the outer side when the pneumatic tire 10 is mounted on the vehicle) with respect to the tire equator line CL. Specifically, a plurality (specifically six) of the plurality of circumferential sipes 110 are formed along the tread width direction D _T in the same land portion 20 defined by the recess 200. Further, since the land portion 20 is V-shaped in the tread surface view, a plurality of circumferential sipe 110 is formed so as to gradually deviate from each other in the tire circumferential direction D _C.

Similarly, a plurality of circumferential sipes 120 are formed on the other side (for example, the inner side when the pneumatic tire 10 is mounted on the vehicle) with respect to the tire equator line CL. Specifically, a plurality (specifically six) of the plurality of circumferential sipes 120 are formed along the tread width direction D _T in the same land portion 20 partitioned by the recess 200. Further, a plurality of circumferential sipe 120 is also formed so as to gradually deviate from each other in the tire circumferential direction D _C.

Circumferential sipe 110 is of the land portions 20 provided plurality in the tire circumferential direction D _C, is formed in a part of the land portion 20. In the present embodiment, in the tire circumferential direction D _C, a land portion 20 of the circumferential sipes 110 are formed, and the land portions 20 of circumferential sipe 110 is not formed is provided alternately.

Similarly, the circumferential sipe 120 is also in the tire circumferential direction D _C, a land portion 20 of the circumferential sipes 120 are formed, and the land portions 20 of circumferential sipe 120 is not formed is provided alternately . Here, the circumferential sipe 120 is not formed in the land portion 20 where the circumferential sipe 110 is formed. On the other hand, the circumferential sipe 110 is not formed in the land portion 20 where the circumferential sipe 120 is formed.

  The recess 200 has a V shape extending from the tire equator line CL side toward the tread shoulder 30 in the tread surface view. The recessed portion 200 is recessed more than the land portion 20 that contacts the road surface.

As described above, in the pneumatic tire 10, only the circumferential sipes 110 and 120 and the recess 200 form a negative portion that cannot contact the road surface. Further, since the land portion 20 and the recesses 200 are V-shaped in the tread surface view negative portion, specifically, a position circumferential sipe 110, 120 and recesses 200 are formed, in the tire circumferential direction D _C The tread width direction D _T changes outside (or inside) as it travels along.

(2) Shape of Circumferential Sipe Next, the shape of the circumferential sipe 110 (120) will be described with reference to FIG. FIG. 2 is a partially enlarged perspective view of the tread portion of the pneumatic tire 10. Since the circumferential sipe 120 has a symmetrical shape with the circumferential sipe 110 with respect to the tire equator line CL, in the following description, the shape of the circumferential sipe 110 will be described.

One end 111 in the tire circumferential direction D _C of the circumferential sipe 110 is communicated with the recess 200. Similarly, the other end portion 112 in the tire circumferential direction D _C of the circumferential sipe 110 is also in communication with the recess 200. That is, the circumferential sipe 110 extends to the recess 200.

  Specifically, the concave portion 200 that communicates with the end portion 111 and the concave portion 200 that communicates with the end portion 112 are adjacent to each other via the land portion 20 where the circumferential sipe 110 is formed.

Circumferential sipe 110, the total length L1 in the tire circumferential direction D _C of the recess 200 recess 200 end 111 are communicated, and that end portion 112 is communicated is longer than the contact length L _R of the pneumatic tire 10. Note that the contact length L _R means that the pneumatic tire 10 contacts the road surface in a state where a normal load is applied to the pneumatic tire 10 set to a normal internal pressure defined by the Japan Automobile Tire Association (JATMA). This is the length of the tread.

Further, since the land portion 20 and the recesses 200 are V-shaped in the tread surface view, a portion in the tire circumferential direction D _C of the circumferential sipes 110, overlap in the tread width direction D _T and another circumferential sipe 110 Formed as follows. For example, the most part in the tire circumferential direction D _C of the tread width direction D _T circumferential sipe 110 formed outside the most tread width direction D _T tread width direction D _T than the circumferential sipes 110 are formed on the outer It is formed so as to overlap with the circumferential sipe 110 formed inside.

(3) Shape of Recess Next, the shape of the recess 200 will be described with reference to FIGS. FIG. 2 is a partially enlarged perspective view of the tread portion of the pneumatic tire 10 as described above. FIG. 3 is a cross-sectional view of the recess 200 taken along line F3-F3 shown in FIG. 4 is a cross-sectional view of the recess 200 taken along line F4-F4 shown in FIG. FIG. 5 is an enlarged perspective view of the recess 200.

As shown in FIGS. 2 to 5, a plurality of raised portions 210 that are raised from the bottom portion 205 of the recessed portion 200 are formed in the recessed portion 200. Ridges 210, cross-sectional shape along the tread width direction D _T is domed (arcuate) are multiply formed along the tread width direction D _T. Thus, since a plurality of raised portions 210 having a dome-shaped cross section are formed in the recess 200 along the tread width direction _DT , the surface of the recess 200 is mainly configured by a curved surface.

The raised portion 210 is formed at a position different from the circumferential sipe 110 in the tread width direction _DT . Specifically, in the tread width direction _DT , the circumferential sipe 110 is formed between the adjacent raised portions 210. Furthermore, the top portion 210a of the raised portion 210 has substantially the same height as the land portion 20 with respect to the bottom portion 205. That is, the top portion 210a is in contact with the road surface in the same manner as the land portion 20.

As shown in FIGS. 3 to 5, a flat intermediate groove 230 is formed between the adjacent raised portions 210. Further, one end portion in the tire circumferential direction D _C of the ridges 210, the inclined portion 211 is gradually inclined toward the bottom portion 205 of the recess 200 is formed. As shown in FIG. 4, the cross-sectional shape along the tire circumferential direction D _C of the inclined portion 211 is curved round.

Further, in the concave portion 200, a width direction groove portion 250 is formed between the inclined portion 211 and the land portion 20. Width groove portion 250 along the end portion in the tire circumferential direction D _C of the land portion 20, extending from the tire equator line CL side to the tread shoulder 30 (see Figure 1).

(4) Advantageous Effects According to the pneumatic tire 10, the circumferential sipes 110, the recess 200 of the end portion 111 are communicated, and the total length L1 in the tire circumferential direction D _C of the recess 200 to end 112 is communicated with the The contact length L _R of the pneumatic tire 10 is longer. A part in the tire circumferential direction D _C of the circumferential sipe 110 (120), are formed in the tread width direction D _T to overlap the other circumferential sipe 110. Specifically, the position where a plurality of circumferential sipe 110 (120) and the recesses 200 are formed is changed in the tread width direction D _T outside (or inside) taken to travel along the tire circumferential direction D _C.

In other words, regardless of the position of the tread of the pneumatic tire 10 for contact with a road surface, always one of the circumferential sipes 110 is a state of the ground contact surface of the pneumatic tire 10 is straddling in the tire circumferential direction D _C. For this reason, rainwater that enters the ground contact surface is discharged outside the contact surface via the circumferential sipe 110, and the drainage of the pneumatic tire 10 can be secured.

  Further, in the pneumatic tire 10, only the circumferential sipes 110 and 120 and the recess 200 constitute a negative portion that cannot contact the road surface. For this reason, the rigidity of the land portion 20 can be remarkably increased as compared with a conventional pneumatic tire having a complicated land portion shape. If the rigidity of the land portion 20 can be increased in this way, the deformation of the land portion 20 with respect to the input to the pneumatic tire 10 is also suppressed, and the handling stability of the automobile equipped with the pneumatic tire 10 is improved.

  That is, according to the pneumatic tire 10, sufficient drainage performance and steering stability can be ensured even when the torque in the low rotation range is high, such as an electric vehicle or a hybrid vehicle.

In the present embodiment, a recess 200 extending from the tire equator line CL side toward the tread shoulder 30 is formed. Further, the recess 200 is V-shaped when viewed from the tread surface, and a plurality of the recesses 200 are formed in the tire circumferential direction. Furthermore, the end portions 111 and 112 of the circumferential sipe 110 (120) communicate with the recess 200. For this reason, rainwater that has entered the ground contact surface is discharged in the tread width direction _DT via the circumferential sipe 110 and the recess 200. Therefore, according to the pneumatic tire 10, necessary and sufficient drainage can be ensured with a minimum groove volume (negative rate).

In the present embodiment, a plurality of raised portions 210 raised from the bottom portion 205 of the recess 200 are formed. The raised portion 210 is formed at a position different from the circumferential sipe 110 (120) in the tread width direction _DT . For this reason, the rigidity of the recess 200 and the periphery of the recess can be increased, and the steering stability of the automobile equipped with the pneumatic tire 10 can be further improved.

Further, according to the pneumatic tire 10, a plurality of raised portions 210 raised from the bottom portion 205 are formed, and the raised portions 210 function in the same manner as a thin rib-shaped land portion. Thus, the ridges 210 that functions similarly to the thin rib-shaped land portion extending along the tire circumferential direction D _C, deformation in the tire circumferential direction D _C of the land portion 20 at the time of braking is suppressed, improving the braking performance To do. Furthermore, since the plurality of raised portions 210 are formed adjacent to each other along the tread width direction _DT , deformation of the land portion 20 with respect to lateral force is suppressed, and cornering power is improved.

(5) Other Embodiments As described above, the contents of the present invention have been disclosed through the embodiments of the present invention. However, it is understood that the description and drawings constituting a part of this disclosure limit the present invention. Should not. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

For example, the embodiment of the present invention can be modified as follows. FIG. 6 is a partial plan view of a tread portion of a pneumatic tire 10A according to a modified example of the present invention. As shown in FIG. 6, the pneumatic tire 10A is provided with a straight rib-like land portion 40 extending along the tire circumferential direction D _C. The rib-like land portion 40 is provided at a position including the tire equator line CL.

A plurality of circumferential sipes, specifically, circumferential sipes 130, 140, and 150 are formed in the rib-like land portion 40. Circumferential sipe 130, 140, 150 is a linear fine groove along the tire circumferential direction D _C. Some in the tire circumferential direction D _C of the circumferential sipe 130 is overlapped with a portion in the tire circumferential direction D _C of the circumferential sipes 140 in the tread width direction D _T. A part in the tire circumferential direction D _C of the circumferential sipes 140, which overlaps with a portion in the tire circumferential direction D _C of the circumferential sipes 150 in the tread width direction D _T.

The end portion 131A in the tire circumferential direction D _C of the circumferential sipe 130 is terminated within the rib-like land portion 40. The same applies to the circumferential sipes 140 and 150.

The length L1A of the circumferential sipe 130 is longer than the contact length L _R of the pneumatic tire 10A. Note that the contact length L _R is a tread portion where the pneumatic tire 10A contacts the road surface in a state where a normal load is applied to the pneumatic tire 10A set to the normal internal pressure, as with the pneumatic tire 10 described above. Is the length of

  Even with the pneumatic tire 10A having such a shape, as in the case of the pneumatic tire 10 described above, even when the torque in the low rotation range is high, such as an electric vehicle or a hybrid type vehicle, sufficient drainage performance and steering stability are ensured. Can be secured.

In the pneumatic tire 10 (10A), the circumferential sipes 110, 120 (130, 140, 150), was the tire circumferential direction D _C parallel straight, the circumferential sipes, the tire circumferential direction D _C and may not necessarily parallel, but may be inclined at 10 degrees or less with respect to the tire equator line CL. Further, the circumferential sipe does not necessarily have to be a complete straight line in the tread surface view, and may be gently bent.

  As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is determined only by the invention specifying matters according to the scope of claims reasonable from the above description.

10, 10A ... Pneumatic tire
20 ... Rikube
30 ... tread shoulder
40 ... Rib-shaped land
110, 120, 130, 140, 150 ... Circumferential sipe
111, 112… End
131A… End
200 ... recess
205… Bottom part
210 ... Uplift
210a ... top
211 ... Inclined part
230 ... Intermediate groove
250 ... Width direction groove

Claims (8)

A tire including a land portion that contacts a road surface, and a plurality of linear circumferential sipes extending along the tire circumferential direction are formed in the land portion,
The length of the circumferential sipe is longer than the contact length with the road surface in a state where a normal load is applied to the tire,
A portion of the circumferential sipe in the tire circumferential direction overlaps with other circumferential sipe in the tread width direction ,
In the land portion, extending from the tire equator line side toward the tread shoulder, a recessed portion that is recessed from the land portion is formed,
The concave portion is V-shaped in a tread surface view and is formed in a plurality in the tire circumferential direction,
A tire in which a land portion where the circumferential sipe is formed and a land portion where the circumferential sipe is not formed are alternately provided in the tire circumferential direction . In the concave portion, a plurality of raised portions protruding from the bottom portion of the concave portion are formed along the tread width direction,
  The tire according to claim 1, wherein the raised portion has an arc shape in cross section along the tread width direction. The tire according to claim 1 , wherein the circumferential sipe extends to the recess. Before SL ridges, tire according to claim 2 in the tread width direction, which is formed at a position different from the circumferential sipe.   The tire according to claim 1, wherein a part of the circumferential sipe in the tire circumferential direction overlaps with another circumferential sipe adjacent in the tread width direction.   The tire according to claim 2, wherein a top portion of the raised portion has substantially the same height as the land portion with reference to a bottom portion of the concave portion.   At one end in the tire circumferential direction of the raised portion, an inclined portion that is gradually inclined toward the bottom portion of the concave portion is formed,
  The tire according to claim 2, wherein a widthwise groove portion is formed in the concave portion between the inclined portion and the land portion.   The tire according to claim 2, wherein a flat intermediate groove is formed between the adjacent raised portions.

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