WO2008065947A1 - Pneumatic tire - Google Patents

Abstract

A pneumatic tire simultaneously satisfying both on-ice turning performance and ice braking performance and also simultaneously satisfying both dry turning performance and dry braking performance. The pneumatic tire has a tread pattern (T) having land sections such as blocks (1) in which sipes (10) are formed. First sipes (10) are provided in a region (Ai) on the inner side, in the direction of installation of the tire on the vehicle, of a tire equator line (CL), and second sipes (20) are provided in a region (Ao) on the outer side of the tire equator line (CL). The first sipes (10) each have a recessed or projected engagement section in a cross-section parallel to the tire equator line (CL). In each second sipe (20), an inner wall surface extending in a tire width direction (WD) or in a direction inclined from the tire width direction has rows of grooves and ridges, and each row has a portion inclined in the direction where the sipe are formed.

Description

 Specification

 Pneumatic tire

 Technical field

 [0001] The present invention relates to a pneumatic tire including a tread pattern in which a land portion having a so-called three-dimensional sipe is formed, and is particularly useful as a studless tire (winter tire). Background art

 Conventionally, in order to improve the ice performance of a studless tire, a tire pattern in which a plurality of sipes are arranged in each part (center part, mediate part, shoulder part) is known. By forming such sipes in blocks, the edge effect, water removal effect, and adhesion effect are improved, so the number of sipes tends to increase in recent years.

 [0003] Increasing the number of sipe and increasing the sipe density increases the number of edges, but the number of edges increases, but the rigidity of the entire block decreases and the sipe collapses excessively. As the size becomes smaller and the ground contact area becomes smaller, the ice performance deteriorates. For this reason, so-called 3D sipe (three-dimensional sipe) has been developed as a method of suppressing sipe collapse.

 [0004] For example, the following Patent Document 1 discloses a three-dimensional sipe that is zigzag-connected in the depth direction while the concavo-convex rows on the sipe inner wall surface are alternately inclined in the sipe longitudinal direction (lateral direction). . In this sipe, the uneven row has a zigzag amplitude in the horizontal direction, so the effect of suppressing the movement of the block piece in the horizontal direction is large, but the effect of suppressing the movement in the front-rear direction is small.

 [0005] Further, Patent Document 2 below discloses a three-dimensional sipe in which a corrugated sipe has a reference surface extending in the depth direction, and a concave engaging portion is provided on each of the front side top portion and the back side top portion. It has been done. In this sipe, since the concave engaging portions are provided at the front side top portion and the back side top portion, respectively, the effect of suppressing the movement of the block piece in the front-rear direction is large, and the effect of suppressing the lateral movement is small. .

 [0006] Patent Document 1: Japanese Patent No. 3504632

Patent Document 2: Japanese Patent No. 3516647 Disclosure of the invention

 Problems to be solved by the invention

[0007] However, since the three-dimensional sipe as described above is premised on the provision of the same type in each part of the tread, when the three-dimensional sipe as described above is provided, the ice turning performance and the ice It was difficult to achieve both braking performance. Also for dry performance

It was difficult to achieve both turning performance and braking performance.

[0008] Therefore, an object of the present invention is to provide a pneumatic tire that can achieve both ice turning performance and ice braking performance, and that can achieve both turning performance and braking performance in terms of dry performance. It is in.

 Means for solving the problem

 [0009] The above object can be achieved by the present invention as described below.

 That is, the pneumatic tire according to the present invention is a pneumatic tire having a tread pattern having a land portion in which a plurality of sipes are formed, and the region inside the tire equator line is parallel to the tire equator line. Provide a first sipe (except for the one corresponding to the second sipe) that has a concave or convex engagement part in the cross section, and the tire equator line outer area is the tire width direction or tire width. The inner wall surface extending along the direction inclined from the direction has a concavo-convex row, and a second sipe having a portion in which the concavo-convex row is inclined in the sipe formation direction is provided. Here, “inside of wearing” refers to the area inside the tire equator when the tire is attached to the vehicle, and “outside of wearing” refers to the tire in the state where the tire is attached to the vehicle. The area outside the equator line. The “sipe formation direction” refers to the direction of the center line of the sipe. For example, in the case of a wavy sipe, the center line of amplitude is the sipe formation direction.

[0010] According to the pneumatic tire of the present invention, the first sipe that greatly suppresses the movement in the front-rear direction is provided in the inner region of the tire equator line that greatly contributes to the braking performance. The area outside the tire equator line, which has a large contribution to the terrain, has a large effect of suppressing lateral movement, and the second sipe is provided, making it possible to achieve both ice turning performance and ice braking performance. As for dry performance, both turning performance and braking performance can be achieved. In other words, the first sipe has a concave or convex engaging portion in a cross section parallel to the tire equator line. It is possible to suppress the movement and improve the braking performance. In the second sipe, the inner wall surface extending along the tire width direction or the direction inclined from the tire width direction has an uneven row, and the uneven row has a portion inclined in the sipe formation direction. When a force is generated, the engagement effect of the concavo-convex rows on the inner wall surface occurs, and the turning performance can be improved by suppressing the lateral movement.

 [0011] In general, it is known that a high load force s is applied to a region outside the wearing when the vehicle turns, and conversely, a contribution to the braking performance is relatively high in a region inside the wearing. In particular, many of the recent vehicles have negative cambers (especially minivans). In this case, the front and back length of the ground contact surface, where the load is greater than the outside of the tire equator, is longer than the outside of the tire.

. Therefore, in such a vehicle, it is particularly effective to provide the first sipe, which has a particularly high effect of suppressing the movement in the front-rear direction, in the region on the inner side of the mounting.

 [0012] In the above, it is preferable that the uneven row of the inner wall surface is provided with a second sipe having a portion inclined to one side in the sipe formation direction and a portion inclined to the opposite side to the portion. Yes. By providing such a second sipe, the engagement effect between the inner wall surface irregularities 歹 IJ is greater when the lateral force of the tire is generated, and the lateral movement is effectively suppressed to improve the turning performance. The ability to squeeze with S.

 [0013] Further, it is preferable that the first sipe has the concave or convex engaging portions at the apexes on both sides in the front-rear direction of the wave sipe. By providing the concave or convex engaging portions at the tops on both sides in the front-rear direction of the wavy sipe, the engagement effect is increased when the front-rear force of the tire is generated, and the movement in the front-rear direction is effectively suppressed. The braking performance can be further increased.

 Brief Description of Drawings

 FIG. 1 is a development view showing an example of a tread pattern in the pneumatic tire of the present invention.

 2 is an enlarged view of a main part showing a block of the tread surface of FIG. 1, (a) is a partially broken perspective view, (b) is a cross-sectional view taken along the line II in (a), (c) Is a cross-sectional view taken along arrow II-II in (a)

 FIG. 3 is an enlarged view of a main part for explaining the relationship between the reference surface and the engaging part in the present invention.

 FIG. 4 is an enlarged view of a main part showing another example of the first sipe according to the present invention.

FIG. 5 is a partially broken perspective view showing the main part of the block forming the second sipe in the present invention. Figure

6] A schematic diagram of the second sipe in the present invention, ω is a cross section of the sipe, (b) is a schematic diagram of the ungrounded state, and (C) is a schematic diagram of the grounded state.

7] A schematic diagram showing another example of the second sipe in the present invention

Explanation of symbols

 1 block

 la Land part tread

 10 First sipe

 10a Top side top

 10b Back side top

 11 Engagement part

 11a Engagement part (front side top)

 l ib engaging part (back side top)

 20 Second sipe

 SI 1st part of 2nd sipe

 S2 Second part of second sipe

 23 Sipe inner wall

 B Reference plane

 D Maximum depth of engagement

 Wl maximum interval

 T tread pattern

 CL tire equator line

PD Tire circumferential direction

WD tire width direction

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a development view showing an example of a tread pattern in the pneumatic tire of the present invention. 2 to 3 are main part views showing an example of the first sipe in the pneumatic tire of the present invention. FIG. 6 is a main part view showing an example of a second sipe in the pneumatic tire of the present invention.

As shown in FIG. 1, the pneumatic tire of the present invention is a block in which a plurality of sipes 10 are formed.

 Equipped with a tread pattern T with land areas such as 1. In the present embodiment, an example is shown in which a block 1 divided by a circumferential groove 2, lateral grooves 3, 5, and oblique grooves 4 is formed, and six rows of blocks 1 are arranged in the tire width direction.

Each block 1 is formed with a plurality of rows of sipes 10 in the tire width direction, and both ends of each sipes 10 are limited to the force that opens in the grooves adjacent to the blocks 1. Depending on the pattern configuration, it can be used appropriately depending on whether it is fastened inside the side wall of the block 1 without being exposed from the side wall of the block 1 or only one side.

[0019] The pneumatic tire of the present invention includes a first sipe 10 having a concave or convex engaging portion 11 in a cross section parallel to the tire equator line CL in a region Ai on the inner side of the tire equator line CL. (Except those corresponding to the second type 20). In the present embodiment, as shown in FIGS. 2 to 3, the first sipe 10 shows an example in which concave engaging portions 11 are provided on the top portions 10 a and 10 b on both sides in the front-rear direction of the wave sipe. In this embodiment, instead of the concave engaging portion 11, a convex engaging portion 11 may be provided.

 [0020] From the viewpoint of improving ice braking performance and dry braking performance, the first sipe 10 preferably accounts for 60% or more of the types provided in the area Ai on the wearing side, and more than 80% More than 90% is preferable.

 [0021] The first sipe 10 has a reference plane B extending in the depth direction from a wavy line on the surface of the block 1, and the reference plane B has substantially the same cross-sectional shape at any depth. Yes. The wavy line is not limited to a sine wave! /, But may be any shape such as a wavy line obtained by alternately combining a straight line and a curved line, a rectangular wave, or a zigzag shape.

 [0022] The period of the wavy line is preferably 1.5 to 4 mm for suitably expressing the so-called waveform sipe characteristics, and the amplitude (the sum of the heights of the tops on both sides) is preferably 1 to 2 mm. Also, the depth of the first sipe 10 is preferably 3 to 1 Omm! /.

[0023] As shown in Fig. 2 (b), the front side top portion 10a of the reference surface B is provided with an engaging portion 11a having a concave longitudinal section, and the back side top portion 10b is shown in Fig. 2 (c). Is provided with an engaging portion l ib having a concave longitudinal section. Both the engaging portion 11a and the engaging portion l ib are formed as conical concave surfaces. In the present invention, the force due to the shape of the engaging portions 11a, l ib As shown in FIG. 3, the maximum depth D from the reference plane B of the engaging portions 11a, l ib of the first sipe 10 is 0.5 ~; 1. 5mm is preferable. When the maximum depth D is less than 0.5 mm, the effect of suppressing the collapse of the first sipe 10 tends to be insufficient. When the maximum depth D exceeds 1.5 mm, the resistance increases during demolding after tire vulcanization molding. There is a direction.

 [0025] The maximum distance W1 in the depth direction of the boundary line 12 between the engaging portions 11a, l ib and the reference plane B is preferably 0.5 to 2.5 mm. If the maximum distance W1 is less than 0.5 mm, the effect of suppressing the collapse of the block 1 tends to be insufficient, and if it exceeds 2.5 mm, the relative engagement portion is related to the maximum depth D. Since the inclination angle of 11a and l ib becomes small, the effect of suppressing the collapse of block 1 tends to be insufficient.

 [0026] When a plurality of engaging portions 11a, l ib are provided at the top and bottom, the vertical distance of the maximum depth portion is preferably 0.5 to 1.5 mm. Further, although the engaging portion 11a and the engaging portion l ib may be provided at different heights, it is preferable to provide them at the same height in order to reduce the influence due to the block falling direction.

 [0027] In the present invention, the smaller the groove width of the first sipe 10, the greater the force of preventing the block 1 from collapsing by the engaging portion, and if the groove width is too small, the edge portion is generated. In order to reduce the effect, the groove width is preferably 0.2 to 0.7 mm.

 [0028] In the present invention, the effect of suppressing the collapse of the block 1 by the engaging portions 11a and l ib is large. Therefore, by increasing the number of the first sipes 10 and increasing the sipe density, the edge effect is increased and the edge effect is obtained. It can be further increased. From this point of view, in the present invention, the sipe density is preferably from 0.3; 2 to 0.3 mm / mm2, more preferably from 0.15 to 0.3 mm / mm2.

 [0029] The engaging portion 11 of the first sipe 10 may be, for example, as shown in FIGS. 4 (al) to (b2). In addition, (al) and (bl) in Fig. 4 are longitudinal sectional views, and (a2) and (b2) in Fig. 4 are front views of the protruding wall facing the sipe.

 [0030] FIGS. 4 (al) and (a2) show an example in which the engaging portion 11 having a concave longitudinal section is formed of a hemispherical concave surface. With a hemispherical concave surface, a higher engagement force can be easily obtained than with a conical concave surface.

In FIG. 4 (bl) and (b2), the engaging portions 11 having a concave longitudinal section are substantially perpendicular to each other. In this example, the boundary line is formed by a concave surface consisting of two horizontal surfaces. In this engaging portion 11, the force that reduces the engaging force in the lateral direction (the direction perpendicular to the paper surface in FIG. 4 (bl)). Since the reference surface B of the first sipe 10 is corrugated, the engaging force in the lateral direction is You can get enough. Similarly to the above, the engaging portion may be formed of a concave surface made of a horizontal cylindrical surface.

 On the other hand, in the pneumatic tire of the present invention, the inner wall surface 23 extending along the tire width direction WD or the tire width direction force is concave in the region Ao outside the tire equator line CL. There is provided a second sipe 20 having a row and a portion in which the concavo-convex row is inclined in the sipe formation direction. In this embodiment, as shown in FIGS. 5 to 6, the uneven portion of the inner wall surface 23 has a first portion S 1 inclined to one side in the tire width direction WD, and the first portion S 1 is reversed. An example is shown in which a second sipe 20 having a second portion S2 inclined to the side is provided.

 [0033] From the viewpoint of improving the ice turning performance and the dry turning performance, the second sipe 20 preferably accounts for 60% or more of the types provided in the area Ao outside the wearing. More than 90% is preferable.

 FIG. 5 is a partially broken perspective view showing the main part of the block according to the present invention. In FIG. 5, the inner wall surface 23 of the second sipe 20 is exposed by breaking a part of the block 1 so that the uneven shape of the inner wall surface 23 is easily componentized.

 In the present embodiment, the first portion S 1, the second portion S 2, and the first portion S 1 are sequentially connected in the depth direction, and the boundary line between the first portion S 1 and the second portion S 2 is An example is shown in which a second sipe 20 is provided in a plane parallel to the land tread la.

 [0036] The cross-sectional shape perpendicular to the concavo-convex row of the second sipe 20 is not limited to a shape close to a sine wave, and any of a wavy line, a square wave, a shape close to a zigzag shape, or the like, in which straight lines and curves are alternately combined. Shape may be sufficient. The period of unevenness in this cross-sectional shape (for example, the distance between the convex and convex tops) is an amplitude that is preferably 1.5 to 5 mm (the sum of the heights of the tops on both sides) in order to achieve the characteristics of the so-called corrugated sipe. ) Is preferably 1.5 to 5 mm.

[0037] The period and amplitude of the unevenness of the first part S1 and the second part S2 may be the same or different, but it is preferable that the period and amplitude of both are the same. Further, when the period and amplitude of the first part S 1 and the second part S 2 are changed, it is preferable to adjust the period and amplitude so that the boundary part between both is continuous. As a result, both are smoothly connected by the wavy boundary line. The inclination direction of the concave-convex row of the first portion SI and the inclination direction of the second portion S2 can be asymmetric with respect to the normal direction of the land tread la.

 Next, the size and the like of each part will be described. The width in the normal direction of each of the first part S1 or the second part S2 in the present invention is preferably 1.5 to 3 mm. The entire depth of the second sipe 20 is preferably 40 to 80% of the main groove depth, that is, 4 to 8 mm. Therefore, the number of consecutive stages of the first part S 1 and the second part S2 is more preferably 3 to 2 to 4 stages.

 [0039] The inclination angle with respect to the normal direction of each of the first portion S1 or the second portion S2 is most preferably 45 °, preferably 30 to 70 °. If the angle is smaller than 30 °, the engagement action between the ridges and the ridges on the sipe inner wall surface 23 when the block is collapsed tends to be small, and if it is larger than 70 °, a bending force is relatively generated near the ground contact surface. The length tends to increase, and the contact pressure tends to be uneven within the block.

 [0040] The groove width of the second sipe 20 is preferably 0.2 to 0.7 mm in order to appropriately express the edge effect while appropriately suppressing the collapse of the block. 0.2 to 0.4 mm Is more preferable.

[0041] In the present invention, the effect of suppressing the collapse of the block 1 by the second portion 22 is large, so by increasing the number of the second sipes 20 and increasing the sipe density, the number of edges can be increased to further enhance the edge effect. Can do. From this point of view, in the present invention, the sipe density is preferably from 0.3; 2 to 0.3 mm / mm2, more preferably from 0.15 to 25 mm / mm2.

 [0042] The second sipe 20 is normally formed with a plurality of forces for one block 1. The adjacent second sipe 20 has the same shape but different wave shape, inclination angle, uneven period, and amplitude. Also good. However, in order to improve the demoldability after vulcanization molding, it is preferable that the adjacent second sipes 20 have the same shape.

 [0043] In the present invention, it is sufficient that the first portion and the second portion have portions alternately arranged in the depth direction of the sipe. For example, as shown in Figs. 7 (a) to (c). A sipe shape as shown may be used. In this figure, the ridges protruding from the back side of the paper surface are shown as 11 and the ridges protruding from the front side of the paper surface are shown as 12 in the sipe unevenness row.

[0044] In FIG. 7 (a), the first part S1 and the second part S2 are connected in series, and the third part S3 extends in the normal direction of the land part tread on the tread side thereof. Is an example in which This rhino Also in the case of the slab, the first portion SI and the second portion S2 can obtain the engaging action between the ridges and the ridges on the inner wall surface of the sipe when the block is collapsed. Further, the presence of the third portion S3 does not increase the bending length acting on the second portion S2, so that the uniformity of the ground pressure in the block can be improved as in the case of the above-described embodiment.

 [0045] FIG. 7 (b) shows an example in which the number of consecutive stages of the first part S1 and the second part S2 is four. In the case of this sipe, compared with the case of the three-stage configuration, the uniform lifetime of the ground pressure in the block can be further increased.

 [0046] In FIG. 7 (c), instead of directly connecting the first part S1 and the second part S2, the first part S1 and the second part S2 are interposed via a short fourth part S4. This is an example in which The fourth part S4 may be a wavy sipe extending in the normal direction of the land tread, or a shape in which the first part S1 and the second part S2 are continuous with a curved surface. By interposing such a fourth part S4, it is possible to improve the demoldability after vulcanization molding while maintaining the effect of suppressing the collapse of the block and the uniformity of the contact pressure within the block to some extent. it can.

 [0047] The pneumatic tire of the present invention is the same as a normal pneumatic tire except that it includes the tread pattern T as described above, and any conventionally known material, shape, structure, manufacturing method, etc. are disclosed in the present invention. Can be adopted.

 [0048] The pneumatic tire of the present invention is particularly useful as a studless tire because it exhibits the above-described effects and is excellent in ice performance.

 [0049] [Other Embodiments]

 Hereinafter, other embodiments of the present invention will be described.

 (1) In the above-described embodiment, the example in which the block having the shape shown in FIG. 1 is formed is shown. The force S and the block are not limited to this shape, but are substantially square, parallelogram, V-shaped. It may be a pentagonal or curved key block. Further, instead of the block, a rib extending linearly in the tire circumferential direction, a rib extending zigzag in the tire circumferential direction, or a lug may be formed.

[0051] (2) In the above-described embodiment, the force S indicating an example in which a plurality of rows of sipes are formed in the tire width direction, and the sipe formation direction (the direction of the center line) is inclined from the tire width direction. The direction may be the same. However, from the viewpoint of balancing tire turning performance and braking performance, The angle formed between the tire direction and the tire width direction is preferably 0 ° to 45 °, more preferably 0 ° to 20 °, and still more preferably 0 ° to 10 °.

[0052] (3) In the above-described embodiment, an example in which the sipe is formed so as to be perpendicular to the block surface is shown. However, the sipe is slightly (eg, 15 ° or less) with respect to the normal of the block surface. ) It may be tilted.

 [0053] (4) In the above-described embodiment, the force same block showing an example in which the sipe in which the concavo-convex rows on the inner wall surface according to the present invention are inclined in a zigzag manner is applied to all the sipes in the tread pattern. It may be applied only to a part of the sipe, or may be applied only to a land part such as a part of a plurality of blocks. When the sipe according to the present invention is applied to only a part of the blocks, it is particularly effective to apply the sipe to the block provided in the shoulder portion of the tire.

 (5) In the above-described embodiment, the example of the first sipe shown in FIGS. 2 to 4 has been shown. However, the first sipe may be a concave or convex engagement in a cross section parallel to the tire equator line. Any sipe described in the following patent document may be applied to the present invention as long as it has a joint.

 [0055] That is, examples of the first sipes include JP-A-4-310407, JP-A-5-58118, JP-A-12-6619, JP-A-10-80923, JP-A-12-17733. Examples disclosed in No. 0 publication and the like.

 (6) In the above-described embodiment, the force S shown in the example of the second sipe shown in FIGS. 5 to 7, and as the second sipe, the inner wall surface extending along the tire width direction has an uneven row. In addition, as long as the concavo-convex row has a portion inclined in the tire width direction, any of the services described in the following patent documents can be applied to the present invention.

 That is, examples of the second sipe include those disclosed in Japanese Patent Application Laid-Open No. 10-258615, Japanese Patent Application Laid-Open No. 11 208223, Japanese Patent No. 3504632, and the like.

 Example

 [0058] Examples and the like specifically showing the configuration and effects of the present invention will be described below. The performance evaluation of tires was performed as follows.

[0059] (1) Ice braking performance

Install tires on actual vehicle (domestic 3000cc class FR sedan) and load conditions for 1 passenger The braking distance when the ABS was operated by running on a frozen road and applying braking force at a speed of 40 km / h was evaluated as an index. The evaluation is shown in the index display when the conventional product (Comparative Example 1) is set to 100. The larger the value, the better the result.

 [0060] (2) Ice turning performance

 The tires were mounted on the same actual vehicle as in (1) above, and the same road surface was run on the Remnise Kart curve (8-shaped curve: R = 25m yen) under the load conditions of one passenger, and the lap time was evaluated as an index. . The evaluation is shown as an index when the conventional product (Comparative Example 1) is set to 100. The larger the value, the better the result.

 [0061] (3) Dry braking performance

 Install the tire on the same actual vehicle as in (1) above, run on a dry road under the load condition of one passenger, and apply the braking force at a speed of 100 km / h as an index to determine the braking distance as an index. evaluated. The evaluation is shown as an index when the conventional product (Comparative Example 1) is set to 100. The larger the value, the better the result.

 [0062] (4) Dry turning performance

 Mount the tire on the same actual vehicle as in (1) above, run on a dry road surface with a load of 1 passenger on the Remnice Kate curve (Figure 8 curve: R = 25m yen), and conduct a sensory test on steering stability Evaluated by index. The evaluation is shown as an index when the conventional product (Comparative Example 1) is set to 100. The larger the number, the better the result.

 [0063] Comparative Example 1 (Conventional product)

 In the tread pattern shown in Fig. 1 !, a normal corrugated sipe (with the surface groove shape extending in the depth direction) with the following dimensions is formed to form a radial tire of size 205 / 65R15 Manufactured. Table 1 shows the results of each performance evaluation described above using this tire. The sipe depth was 7 mm, the sipe groove width was 0.3 mm, the period was 4 mm, the amplitude was 1.8 mm, and the sipe interval was 4 mm.

 [0064] Comparative Example 2

In the tread pattern shown in Fig. 1, radial tires of size 205 / 65R15 were manufactured by forming sipes as shown in Fig. 2 in the areas inside and outside the installation. Table 1 shows the results of each performance evaluation described above using this timer. At that time, set the sipe depth to 7 mm, sipe 'groove width 0 · 3mm, period 4mm, amplitude 1 · 8mm, sipe spacing 4mm, engaging depth from block surface 3mm and 6mm, radius 0.75mm, depth 1 A conical concave engaging part of 00 mm was formed.

[0065] Comparative Example 3

 In the tread pattern shown in Fig. 1, radial tires of size 205 / 65R15 were manufactured by forming sipes as shown in Fig. 5 in the areas inside and outside the mounting. Table 1 shows the results of each performance evaluation described above using this timer. At that time, the depth of the entire sipe is 6.9 mm, the groove width is 0.3 mm, the sipe interval is 4 mm, the amplitude of the upper and lower first parts is 1.5 mm, the period is 4. Omm, the width in the spring direction is 2.3 mm, The inclination angle was 45 °, the amplitude of the second part was 1.5 mm, the period was 4. Omm, the width in the normal direction was 2.3 mm, and the inclination angle was 45 °.

[0066] Example 1

 In the tread pattern shown in FIG. 1, a first sipe as shown in FIG. 2 (the dimensions are the same as in Comparative Example 2) is formed on the inner area of the mounting, and a second sipe as shown in FIG. A radial tire of size 205 / 65R15 was manufactured by forming a sipe (the dimensions were the same as in Comparative Example 3). Table 1 shows the results of each performance evaluation described above using this tire.

[0067] Example 2

 In Example 1, instead of the first sipe shown in FIG. 2, a conical convex engagement portion having a radius of 0.75 mm and a depth of 1.00 mm was formed at the top of the corrugated sipe, A first sipe was formed in the same manner as in Example 1 to produce a radial tire of size 205 / 65R15. Table 1 shows the results of each performance evaluation described above using this tire.

[0068] Example 3

 Example 1 is the same as Example 1 except that instead of the first sipe shown in FIG. 2, a conical concave engaging portion having a radius of 0.75 mm and a depth of 1.00 mm is formed on a straight sipe. Thus, the first sipe was formed to produce a radial tire of size 205 / 65R15. Table 1 shows the results of each performance evaluation described above using this timer.

[0069] Comparative Example 4

In Example 1, a radial tire was manufactured in the same manner as in Example 1 except that the second sipe was formed on the inner region of the mounting and the first sipe was formed on the outer region of the mounting. It was. Table 1 shows the results of each performance evaluation described above using this tire.

[table 1]

表 1の結果が示すように、実施例；!〜 3では、アイス旋回性能とアイス制動性能とを 両立させることができ、ドライ性能についても旋回性能と制動性能を両立させることが できる。これに対して、装着内側と外側とに同じ三次元サイプを形成した比較例 2〜3 では、アイス旋回性能又はアイス制動性能の何れかの改善効果が小さぐドライ性能 についても同様の結果であった。また、装着内側と外側に設けるサイプを逆にした比 較例 4では、アイス旋回性能とアイス制動性能の両者の改善効果が小さぐドライ性 能についても同様の結果であった。

As shown in the results of Table 1, in Examples;! To 3, it is possible to achieve both ice turning performance and ice braking performance, and it is possible to make both turning performance and braking performance compatible with dry performance. On the other hand, in Comparative Examples 2 to 3 in which the same three-dimensional sipe was formed on the inner side and the outer side, the same result was obtained with respect to the dry performance in which the improvement effect of either ice turning performance or ice braking performance was small. It was. Moreover, in Comparative Example 4 in which the sipe provided on the inner side and the outer side was reversed, the same result was obtained for the dry performance in which the improvement effect of both the ice turning performance and the ice braking performance was small.

Claims

The scope of the claims  [1] In a pneumatic tire having a tread pattern having a land portion in which a plurality of sipes are formed,  A first sipe (except for the one corresponding to the second sipe) having a concave or convex engaging portion in a cross section parallel to the tire equator line is provided in a region inside the tire equator line, and the tire equator In the region outside the line, the inner wall surface extending along the tire width direction or the direction inclined from the tire width direction has a concavo-convex row, and the concavo-convex row has a portion inclined in the sipe formation direction. A pneumatic tire characterized by providing sipes. [2] The pneumatic chamber according to claim 1, wherein the concave-convex row on the inner wall surface is provided with a second sipe having a portion inclined to one side in the sipe formation direction and a portion inclined to the opposite side to the portion. Tya.  [3] The pneumatic tire according to [1] or [2], wherein the first sipe has the concave or convex engaging portions at the apexes on both sides in the front-rear direction of the wave sipe.