JP7381833B2 - pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire with improved wet handling stability performance and passing noise performance.

In recent years, as tire noise regulations have tended to be tightened, technologies have been proposed to improve noise performance while maintaining steering stability and wet performance (for example, due to lateral acceleration of the front wheels) (Patent Document 1) ).

Patent No. 5947824

Patent Document 1 discloses that the first middle sipe includes a full open sipe that communicates from the center main groove to the shoulder main groove, and a first semi-open sipe that communicates with the center main groove at one end and terminates in the first middle land portion at the other end. A full open sipe, a first semi-open sipe, and a second semi-open sipe, including a sipe and a second semi-open sipe whose one end communicates with the shoulder main groove and whose other end terminates within the first middle land portion. , each of which is inclined in the same direction, pneumatic tires are disclosed. In such tires, noise performance can be improved while maintaining handling stability and wet performance by improving the shape of the grooves and sipes provided in the middle land area and shoulder land area. has been done.

In Patent Document 1, for example, referring to FIG. 1, each of the first shoulder land portion 31 and the second shoulder land portion 32 has a first shoulder lateral groove 33 having a substantially arc shape convex on one side in the tire circumferential direction; A plurality of two-shoulder lateral grooves 34 are provided. The extending direction of these grooves is limited to approximately the tire width direction, and moreover, these grooves exist only outside the central region of the land portions 31 and 32 in the tire width direction. For this reason, it cannot be said that the drainage performance is necessarily high, especially in the inner region in the tire width direction of the land portions 31 and 32, since the drainage linkage with the shoulder main grooves 3 and 3 is poor, and as a result, the wet steering stability performance is affected. There is room for improvement.

The present invention has been made in view of the above circumstances , and an object of the present invention is to provide a pneumatic tire with improved wet handling stability performance.

The pneumatic tire according to the present invention has at least two circumferential main grooves on the tread surface, and on each side of the tire width direction of the tire equatorial plane, the tire width is lower than the circumferential main groove located at the outermost side in the tire width direction. A shoulder land portion on the outer side in the width direction and a center land portion on the inner side in the tire width direction than the circumferential main groove located at the outermost side in the width direction of the tire are defined, and the shoulder land portion is provided with sipes and lug grooves. The lug groove is connected to the circumferential main groove, and in the shoulder land portion, the first sipe extends at an angle with respect to the width direction of the tire, and the first sipe extends in a direction different from the first sipe. An extending second sipe is formed.

In the pneumatic tire according to the present invention, the manner in which the sipes and grooves are formed in the shoulder land portion has been improved. As a result, according to the pneumatic tire according to the present invention , wet steering stability performance can be improved.

FIG. 1 is a plan view showing the tread surface of the pneumatic tire of this embodiment. FIG. 2 is a plan view showing a tread surface of a modification of the pneumatic tire shown in FIG. 1. FIG.

Embodiments of the pneumatic tire according to the present invention (basic form and additional forms 1 to 9 shown below) will be described in detail below based on the drawings. Note that these embodiments do not limit the present invention. Furthermore, the constituent elements of the embodiments described above include those that can be easily replaced by those skilled in the art, or those that are substantially the same. Furthermore, the various forms included in the above embodiments can be arbitrarily combined within the range obvious to those skilled in the art.

[Basic form]
Below, the basic form of the pneumatic tire according to the present invention will be explained.

In the following explanation, the tire radial direction refers to the direction perpendicular to the rotation axis of the pneumatic tire, the tire radial inside refers to the side facing the rotation axis in the tire radial direction, and the tire radial outside refers to the side in the tire radial direction. This refers to the side away from the rotation axis. Further, the tire circumferential direction refers to a direction around the rotation axis as the central axis. Furthermore, the tire width direction refers to a direction parallel to the rotational axis, the inside in the tire width direction is the side facing the tire equatorial plane CL (tire equator line) in the tire width direction, and the outside in the tire width direction is the direction in the tire width direction. refers to the side away from the tire equatorial plane CL. Note that the tire equatorial plane CL is a plane that is perpendicular to the rotation axis of the pneumatic tire and passes through the center of the tire width of the pneumatic tire.

FIG. 1 is a plan view showing a tread surface of a pneumatic tire according to an embodiment of the present invention. Note that the symbol CL in FIG. 1 indicates the tire equatorial plane. Further, the tread pattern shown in FIG. 1 is a pattern that is symmetrical between both sides in the tire width direction of the tire equatorial plane CL, but the pneumatic tire of this embodiment is symmetrical between both sides in the tire width direction of the tire equatorial plane CL. It is not limited to asymmetrical patterns, but also includes asymmetrical patterns.

The tread portion 10 of the pneumatic tire of this embodiment is made of a rubber material (tread rubber). The surface of the tread portion 10 located at the outermost position in the tire radial direction (tread surface 12) comes into contact with the road surface when the vehicle is running. Further, as shown in FIG. 1, a predetermined tread pattern, which will be described in detail below, is formed on the tread surface 12.

As shown in FIG. 1, the tread surface 12 has at least two circumferential main grooves (three circumferential main grooves 14a, 14b, and 14c shown in the figure) extending in the tire circumferential direction. In this embodiment, the width of the circumferential main groove is 5 to 15 mm, and the depth of the circumferential main groove is 4 to 8 mm.

By forming the circumferential main grooves 14 in this manner, the tread surface 12 has a circumferential main groove located at the outermost side in the tire width direction (as shown in FIG. Shoulder land portions S1, S2 on the outer side in the tire width direction than the circumferential main grooves 14a, 14c) and center land portions C1, C2 on the inner side in the tire width direction than the circumferential main grooves 14a, 14c are defined. There is.

Under the above premise, in this embodiment, as shown in FIG. 1, sipes 16a, 16b and lug grooves 17 are provided in shoulder land portions S1, S2. Specifically, the shoulder land portions S1 and S2 include a first sipe 16a that extends obliquely with respect to the tire width direction, a second sipe 16b that extends in the tire circumferential direction, and a circumferential main sipe 16b that extends in the tire width direction. A lug groove 17 is formed that communicates with the grooves 14a and 14c and extends obliquely with respect to the tire width direction. In the example shown in the figure, the second sipe 16b communicates with both the first sipe 16a and the lug groove 17.

Further, first sipes 16a, second sipes 16b, and lug grooves 17 are formed in the shoulder land portions S1 and S2 at equal intervals in the tire circumferential direction, respectively. Furthermore, the two second sipes 16b, 16b extending from one lug groove 17 are formed at different positions in the tire width direction.

Here, the first sipe 16a may be linear as shown in FIG. 1, or may be curved. Regardless of the shape of the first sipe 16a, the inclination of the straight line connecting both end points thereof can be 55° or less with respect to the tire width direction. The inclination defined in this embodiment means an acute angle or a right angle with a reference direction (for example, tire width direction).

Moreover, the second sipe 16b may be linear as shown in FIG. 1, or may be curved. Regardless of its shape, the second sipe 16b can have an inclination angle of 60° or more and 90° or less with respect to the tire width direction of a straight line connecting both end points thereof.

Furthermore, the lug groove 17 may be linear as shown in FIG. 1, or may be curved. Regardless of its shape, the lug groove 17 can have an inclination angle of 0° or more and 45° or less with respect to the tire width direction of a straight line connecting both end points thereof.

On the other hand, as shown in FIG. 1, the center land portion C1 (C2) has a third sipe 16c that communicates with both the circumferential main grooves 14a, 14b (14b, 14c) on both sides, and a third A fourth sipe 16d is formed extending from the sipe 16c to one side in the tire circumferential direction and terminating within the land portion. In this embodiment, the third sipe 16c and the fourth sipe 16d are each formed at equal intervals in the tire circumferential direction. In addition to the sipes 16c and 16d shown in FIG. 1, the center land portion C1 (C2) may include grooves (for example, grooves whose width and depth are smaller than the circumferential main grooves 14a to 14c) as necessary. (the extending direction and shape are arbitrary) or other sipes can also be formed.

The third sipe 16c may be linear as shown in FIG. 1, or may be curved. Regardless of the shape of the third sipe 16c, the inclination of the straight line connecting both end points thereof can be 40° or less with respect to the tire width direction.

The fourth sipe 16d may be linear as shown in FIG. 1, or may be curved. Regardless of the shape of the fourth sipe 16d, the slope of the straight line connecting both end points of the fourth sipe 16d can be set to 45° or more and 90° or less with respect to the tire width direction.

In this embodiment, the width of the sipes 16a to 16d is 0.2 to 2 mm, and the depth of the sipes 16a to 16d is 1 to 8 mm.

(effect, etc.)
Conventionally, a plurality of roughly arc-shaped lug grooves that are convex on one side in the tire circumferential direction are provided near the ground contact end of the shoulder land portion, and these lug grooves are different from the widest groove extending in the tire circumferential direction. Many of them terminated on land at both ends without communicating with each other. In the pneumatic tire of the present embodiment, since the lug grooves 17 communicate with the circumferential main grooves 14a, 14c, the circumferential main grooves 14a, 14c are particularly in the inner regions in the tire width direction of the shoulder land portions S1, S2. Due to the drainage interlock between the lug groove 17 and the lug groove 17, excellent drainage performance can be achieved, and in turn, excellent wet steering stability can be achieved (effect 1).

Therefore, according to the pneumatic tire of the present embodiment , excellent wet steering stability can be achieved by the above-mentioned effect 1.

Although not shown, the pneumatic tire according to the present embodiment described above has a meridional cross-sectional shape similar to that of a conventional pneumatic tire. Here, the meridional cross-sectional shape of the pneumatic tire refers to the cross-sectional shape of the pneumatic tire appearing on a plane perpendicular to the tire equatorial plane. The pneumatic tire of this embodiment has a bead portion, a sidewall portion, a shoulder portion, and a tread portion from the inside in the tire radial direction toward the outside in a meridional cross-sectional view of the tire. The pneumatic tire includes, for example, a carcass layer that extends from the tread portion to bead portions on both sides and is wound around a pair of bead cores, and a carcass layer on the outside of the carcass layer in the tire radial direction, for example, in a meridional section view of the tire. A belt layer and a belt reinforcing layer are formed in this order.

In addition, the pneumatic tire of this embodiment is manufactured through normal manufacturing processes, such as a tire material mixing process, a tire material processing process, a green tire molding process, a vulcanization process, and a post-vulcanization inspection process. It is something that can be obtained through time. When manufacturing the pneumatic tire of this embodiment, in particular, on the inner wall of the vulcanization mold, for example, convex portions corresponding to the sipes, lug grooves, and land portions formed in the tread portion shown in FIG. and recesses are formed, and vulcanization is performed using this mold.

[Additional form]
Next, additional embodiments 1 to 9 which can be optionally implemented with respect to the above-mentioned basic embodiment of the pneumatic tire according to the present invention will be explained.

(Additional form 1)
In the basic form, it is preferable that the inclination angle θ1 of the first sipe 16a shown in FIG. 1 with respect to the tire width direction is 45° or less (additional form 1). In order to ensure the rigidity of the shoulder land portions S1 and S2, the tire width direction dimension of the first sipe 16a from the circumferential main groove 14a (14c) to the end position within the land portion is kept constant without being excessively large. In this case, the smaller the inclination angle θ1, the smaller the actual size of the first sipe 16a. In this embodiment, since the inclination angle θ1 is set to 45° or less, the actual size of the first sipe 16a does not become excessively large, and the surface area of the first sipe 16a can be reduced, which improves the passing noise performance. can be further increased.

Further, in this embodiment, since the inclination angle θ1 is set to 45° or less, the surface area of the first sipe 16a can be reduced as described above. Therefore, the rigidity of the shoulder land portions S1 and S2 can be further increased to further improve the wet steering stability performance.

In addition, when the inclination angle θ1 is set to 40° or less, each of the above effects is achieved at a high level, which is more preferable, and when the inclination angle θ1 is set to 35° or less, each of the above effects is achieved at an even higher level. This is extremely desirable.

(Additional form 2)
In the basic form or a form in which additional form 1 is added to the basic form, the inclination angle θ2 of the second sipe 16b with respect to the tire width direction shown in FIG. 1 is 45° or more and 90° or less (additional form 2). is preferred. In the example shown in FIG. 1, the second sipe 16b extends in the tire circumferential direction, and the inclination angle θ2 is 90°.

In order to ensure the rigidity of the shoulder land portions S1 and S2, if the tire circumferential dimension of the second sipe 16b from the first sipe 16a to the lug groove 17 is kept constant without being excessively large, the slope When the angle θ2 is 90°, the actual size of the second sipe 16b becomes the smallest, and when it is less than 45°, the actual size becomes excessively large. In the present embodiment, since the inclination angle θ2 is set to 45° or more and 90° or less, the actual size of the second sipe 16b does not become excessively large, and the surface area of the second sipe 16b can be made small. Passing noise performance can be further improved.

Further, in this embodiment, since the inclination angle θ2 is set to 45° or more and 90° or less, the surface area of the second sipe 16b can be reduced as described above. Therefore, the rigidity of the shoulder land portions S1 and S2 can be further increased to further improve the wet steering stability performance.

It is more preferable to set the inclination angle θ2 to 50° or more and 90° or less, since the above effects are achieved at a high level, and it is more preferable to set the inclination angle θ2 to 55° or more and 90° or less. This is extremely preferable because each of these is played at an even higher level.

(Additional form 3)
In the basic form or a form in which at least one of additional form 1 and additional form 2 is added to the basic form, an area of 30% or more and 70% or less of the tire width direction area of the first sipe 16a shown in FIG. It is preferable that there is a region where the second sipe 16b is formed (additional form 3). Here, the formation area of the second sipe 16b refers to the entire area where the second sipe 16b is formed, and even a partial area that deviates from the above range is not included in this embodiment. .

In the example shown in FIG. 1, the tire width direction region of the first sipe 16a is represented by the symbol L1. Here, the innermost position in the tire width direction is defined as the 0% position, and the outermost position in the tire width direction is defined as the 100% position. In this embodiment, the second sipe 16b is formed in the area from the 30% position to the 70% position. That is, the second sipe 16b is not brought too close to the circumferential main groove 14a (14c), and the second sipe 16b is not brought too close to the ground contact edge at the outermost position in the width direction of the tire in the area indicated by the symbol L1. Not yet. As a result, the rigidity near the circumferential main grooves 14a (14c) of the shoulder land portions S1 and S2 can be increased, and the rigidity near the contact edges can be increased, and wet steering stability performance can further be improved. .

In addition, when the formation area of the second sipe 16b is present in an area of 35% or more and 65% or less of the area of the first sipe 16a in the tire width direction, the above-mentioned effects are achieved at a high level. preferable. Furthermore, if the formation area of the second sipe 16b is present in an area of 40% or more and 60% or less of the area of the first sipe 16a in the tire width direction, each of the above effects is achieved at an even higher level. Highly preferred.

(Additional form 4)
In the basic form or a form in which at least one of Additional Forms 1 to 3 is added to the basic form, the tire circumferential dimension of the second sipe 16b is 35% of the pitch length of the first sipe 16a. % or more and 65% or less (additional form 4).

In the example shown in FIG. 1, the tire circumferential dimension of the second sipe 16b is represented by the symbol L2, and the pitch length of the first sipe 16a is represented by the symbol P1. In this embodiment, by setting the tire circumferential dimension of the second sipe 16b to 35% or more of the pitch length of the first sipe 16a, a sufficient surface area of the second sipe 16b can be secured. can. Therefore, the drainage performance of the shoulder land portions S1 and S2 can be further improved, and the wet steering stability performance can be further improved.

On the other hand, by setting the tire circumferential dimension of the second sipe 16b to 65% or less of the pitch length of the first sipe 16a, it is possible to suppress the surface area of the second sipe 16b from becoming excessively large. As a result, passing noise performance can be further improved.

In addition, by setting the tire circumferential direction dimension of the second sipe 16b to 37% or more and 62% or less of the pitch length of the first sipe 16a, each of the above effects can be achieved at an even higher level. By setting the ratio to 60% or less, each of the above effects can be achieved at an extremely high level.

(Additional form 5)
FIG. 2 is a plan view showing a tread surface of a modification of the pneumatic tire shown in FIG. 1. FIG. In the basic form or a form in which at least one of additional forms 1 to 4 is added to the basic form, at least two second sipes (the same In the example shown in the figure, it is preferable that the two sipes 16b, 16b) extend on the same side in the tire circumferential direction (additional form 5).

By communicating at least two second sipes with each of the first sipes 16a shown in FIG. 2, drainage performance can be further improved. Furthermore, by extending each of the second sipes on the same side in the tire circumferential direction as the first sipe 16a, drainage performance can be efficiently improved, especially for tires whose rotation direction is specified. I can do it. As described above, according to the pneumatic tire of the type shown in FIG. 2, wet steering stability performance can be further improved.

(Additional form 6)
In the basic form or a form in which at least one of Additional Forms 1 to 5 is added to the basic form, the center land portions C1 and C2 shown in FIG. 1 or 2 are located on both sides in the tire width direction. A third sipe 16c that communicates with at least one (both in both figures) of the circumferential main grooves 14a, 14b (14b, 14c) and has an inclination angle θ3 of 45° or more and less than 90° with respect to the tire width direction; It is preferable that a fourth sipe 16d is formed which communicates with the sipe 16c and extends in the tire circumferential direction (additional form 6).

The third sipe 16c communicates with the circumferential main groove at least at one end thereof, and its maximum dimension in the tire width direction is the dimension between the two circumferential main grooves. When the dimension of the third sipe 16c in the tire width direction is constant, when the inclination angle θ3 is increased, the actual dimension of the third sipe 16c becomes larger. In this embodiment, since the inclination angle θ3 is set to 45° or more, the actual size of the third sipe 16c can be sufficiently secured, the surface area of the third sipe 16c can be increased, and the wet steering stability can be improved. can be further increased. Note that when the inclination angle θ3 is 90°, the actual size of the third sipe 16c is ∞. Therefore, in this embodiment, the inclination angle θ3 is set to be less than 90°.

Note that by setting the inclination angle θ3 to 50° or more, the above effect can be achieved at an even higher level, and by setting the inclination angle θ3 to 55% or more, the above effect can be achieved at an extremely high level.

(Additional forms 7, 8)
In the basic form or a form in which at least one of additional forms 1 to 6 is added to the basic form, the circumferential main grooves 14a, 14c shown in FIG. 1 or 2 communicate with the first sipe 16a. A recess 18 is formed in the portion (additional form 7), and/or a communicating portion between the circumferential main grooves 14a, 14b, 14c and the third sipe 16c shown in FIG. 1 or 2, Preferably, a recess 20 is formed (additional form 8).

By forming the recesses 18 and 20, drainage performance can be improved. In addition, by forming the recesses 18 and 20, it is possible to suppress blistering of the land portions near the communication points between the circumferential main grooves 14a and 14c and the first sipe 16a when the vehicle is running. As described above, according to the present embodiment, it is possible to uniform ground pressure, improve uneven wear resistance, and achieve excellent wet steering stability over a long period of time.

(Additional form 9)
In the basic form or a form obtained by adding at least one of additional forms 1 to 8 to the basic form, a directional pattern (additional form 9) is preferable. Here, the directional pattern refers to a pattern in which the direction of rotation of the vehicle is specified. For example, in the example shown in FIG. 1, since there are two directions in which the second sipe 16b extends from the first sipe 16a, the rotation direction is not specified and the pattern is non-directional. On the other hand, in the example shown in FIG. 2, since the second sipe 16b extends from the first sipe 16a in only one direction, the rotation direction is specified and the pattern is a directional pattern.

In the tire shown in FIG. 2, if the communication side of the second sipe 16b with the first sipe 16a is used as the stepping side, and the lug groove side of the second sipe 16b is used as the kicking side, the tire shown in FIG. Drainage performance is much higher than when using a water pump, making it possible to achieve better drainage performance and wet steering stability.

The tire size is 185/65R15, and the circumferential main grooves 14a to 14c, the first sipe 16a, the second sipe 16b, the third sipe 16c, the fourth sipe 16d, and the lug groove 17 shown in FIG. 1 or 2 are used. Pneumatic tires of Invention Example 1 to Invention Example 9 were prepared, which were equipped with the following and satisfied each of the conditions shown in Tables 1 to 3. On the other hand, the tire size is 185/65R15, and the circumferential main grooves 14a to 14c, the first sipe 16a, the second sipe 16b, the third sipe 16c, and the fourth sipe 16d are shown in FIG. 1 or 2. In addition, shoulder land portions S1 and S2 have lug grooves 33 and 34 as shown in FIG. ), and a conventional pneumatic tire satisfying each of the conditions shown in Tables 1 to 3 was manufactured.

Note that the terms used in each of the conditions shown in Tables 1 to 3 (shoulder land areas S1, S2, center land areas C1, C2, first sipe 16a, second sipe 16b, third sipe 16c, fourth sipe) 16d, lug groove 17, recesses 18, 20, L1, L2, P1, θ1 to θ3) all indicate the constituent members and dimensions indicated by the respective symbols shown in FIG. 1 or 2.

Each test tire (each example and conventional example) was mounted on a rim of size 5.5J, the air pressure was set to 210 kPa, and these were mounted on a front engine/front drive type vehicle with a displacement of 1500 cc. All of these test tires were evaluated for passing noise performance and wet handling stability performance as follows. These results are shown in Tables 1 to 3.

(passing noise performance)
Passing noise performance was evaluated according to the tire noise test method specified in ECE R117-02 (ECE Regulation No.117 Revision 2). In this test, the test vehicle was run sufficiently before the noise measurement section, the engine was stopped before the section, and the maximum noise value (dB) in the noise measurement section was measured by ± with respect to the reference speed. A speed range of 10 km/hour was divided into eight or more speeds at approximately equal intervals, and the average was taken as the passing noise (outside the vehicle). The maximum noise value in dB is the sound measured through an A-weighted frequency correction circuit using a stationary microphone installed 7.5 m laterally from the center line of travel and 1.2 m above the road surface at the midpoint of the noise measurement section. pressure [dB(A)]. Note that the sound pressure shown in Tables 1 to 3 was evaluated as an index with the conventional example set as 100. In Tables 1 to 3, the higher the numerical value, the lower the sound pressure, that is, the higher the passing noise performance.

(Wet handling stability performance)
Wet steering stability performance was evaluated by evaluating the average lateral acceleration when the vehicle ran five laps around a 30 m radius turning path at a limit speed on a wet road surface with a water depth of approximately 1 mm at an outdoor tire testing site. Note that the average lateral acceleration shown in Tables 1 to 3 was evaluated as an index with the conventional example set as 100. In Tables 1 to 3, the higher the numerical value, the higher the average lateral acceleration, that is, the higher the wet steering stability performance.

According to Tables 1 to 3, the shoulder land portion is provided with sipes and lug grooves, and in the shoulder land portion, the first sipe extends at an angle with respect to the tire width direction, and the first sipe extends in the tire circumferential direction. Regarding the pneumatic tires of Invention Examples 1 to 9, which fall within the technical scope of the present invention, in which a second sipe is formed, all of the pneumatic tires of the prior art examples that do not fall within the technical scope of the present invention It can be seen that the passing noise performance and wet handling stability performance are improved in a well-balanced manner compared to the standard tires.

10 Tread portion 12 Tread surface 14a, 14b, 14c Circumferential main groove 16a, 16b, 16c, 16d Sipe 17 Lug groove 18, 20 Concave portion C1, C2 Center land portion CL Tire equatorial plane L1 Tire width direction of first sipe 16a Area L2 Dimension in the tire circumferential direction of the second sipe 16b P1 Pitch length of the first sipe 16a S1, S2 Shoulder land portion θ1 Inclination angle of the first sipe 16a with respect to the tire width direction θ2 Tire width of the second sipe 16b Inclination angle with respect to the direction θ3 Inclination angle of the third sipe 16c with respect to the tire width direction

Claims (9)

A shoulder land portion comprising at least two circumferential main grooves on the tread surface, and on each side of the tire width direction of the tire equatorial plane, an outermost circumferential main groove in the tire width direction than the outermost circumferential main groove in the tire width direction; A pneumatic tire defined by a center land portion located on the inner side in the width direction of the tire than the circumferential main groove located on the outermost side in the width direction of the tire,
A sipe and a lug groove are provided in the shoulder land portion,
The lug groove communicates with the circumferential main groove,
In the shoulder land portion, a first sipe extending obliquely with respect to the tire width direction and a second sipe extending in a direction different from the first sipe are formed,
In the center land portion, a third sipe that communicates with at least one of the circumferential main grooves located on both sides in the tire width direction and has an inclination angle of 45° or more and less than 90° with respect to the tire width direction; A pneumatic tire characterized in that a fourth sipe is formed which communicates with the sipe and extends in the circumferential direction of the tire. The pneumatic tire according to claim 1, wherein the first sipe has an inclination angle of 45° or less with respect to the tire width direction. The pneumatic tire according to claim 1 or 2, wherein the second sipe has an inclination angle of 45° or more and 90° or less with respect to the tire width direction. The pneumatic tire according to any one of claims 1 to 3, wherein the second sipe is formed in an area of 30% or more and 70% or less of the area of the first sipe in the tire width direction. The pneumatic tire according to any one of claims 1 to 4, wherein the tire circumferential dimension of the second sipe is 35% or more and 65% or less of the pitch length of the first sipe. The pneumatic tire according to any one of claims 1 to 5, wherein at least two of the second sipes extend from each of the first sipes to the same side in the tire circumferential direction. The pneumatic tire according to any one of claims 1 to 6, wherein a recess is formed in a communicating portion between the circumferential main groove and the first sipe. The pneumatic tire according to claim 1, wherein a recess is formed in a communicating portion between the circumferential main groove and the third sipe. A pneumatic tire according to any one of claims 1 to 8, which is a directional pattern.