JP2016002886A - Pneumatic tire and method for mounting the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate large lateral force in a specific direction.SOLUTION: A pneumatic tire 1 has a tread part 2 whose rotation direction N is designated. At the tread part 2 are provided spiral grooves 3 which extend spirally around a tire rotary shaft so as to incline from a first tread end Te side to a second tread end Ti side toward the rotation direction N. The spiral grooves 3 have first groove walls 4 close to the first tread end Te side and second groove walls 5 close to the second tread end Ti side. Between one ends 3e and the other ends 3i of the spiral grooves 3, inclination angles β of the second groove walls 5 to a tread normal line n2 are larger than inclination angles α of the first groove walls 4 to a tread normal line n1.

Description

  The present invention relates to a pneumatic tire capable of generating a large lateral force in a specific direction and a method for mounting the pneumatic tire.

  In general, the road surface may be provided with an inclination called a cant. The cant is an inclination in a direction perpendicular to the traveling direction of the vehicle. Patent Document 1 below describes a pneumatic tire in which a tread portion is provided with a spiral groove extending spirally around a tire rotation axis in order to prevent the tire from being worn by cant. Yes. Since such a pneumatic tire generates a lateral force (conicity force) on one side in the tire axial direction by a spiral groove during traveling, the lateral force and the frictional force due to the cant of the road surface are offset, and the tread portion Expected to prevent uneven wear.

  However, Patent Document 1 below does not fully describe generating a greater lateral force during traveling.

JP 2006-137244 A

  The present invention has been devised in view of the above problems, and based on improving the shape of the spiral groove of the tread portion, a pneumatic tire capable of generating a large lateral force in a specific direction. The main purpose is to provide Another object of the present invention is to provide a method for mounting a pneumatic tire having excellent straight running stability performance or steering response performance using such a pneumatic tire.

  1st invention of this application is a pneumatic tire which has a tread part in which the direction of rotation was specified, and inclines from the 1st tread end side to the 2nd tread end side toward the direction of rotation in the tread part. As described above, a spiral groove extending spirally around the tire rotation axis is provided, and the spiral groove includes a first groove wall on the first tread end side and a second groove wall on the second tread end side. And the inclination angle of the second groove wall with respect to the tread normal from the one end to the other end of the spiral groove is larger than the inclination angle of the first groove wall with respect to the tread normal.

  In the pneumatic tire according to the present invention, it is preferable that a difference between the inclination angle of the first groove wall and the inclination angle of the second groove wall is 5 degrees or less.

  In the pneumatic tire according to the present invention, the tread portion includes a first region where the spiral groove is provided, and a plurality of inclined grooves inclined in the same direction as the inclination of the spiral groove in the tire circumferential direction. It is desirable to include the second region.

  A second invention of the present application is a method for mounting the pneumatic tire according to any one of claims 1 to 3 to a four-wheel vehicle, wherein the front left wheel and the front right wheel are provided in the four-wheel vehicle. In addition, a step of attaching a pneumatic tire such that the generated lateral forces are opposite to each other, and a pneumatic tire attached to the front left wheel on the rear left wheel of the four-wheel vehicle are: A step of installing a pneumatic tire that generates a lateral force in the opposite direction and a lateral force in the direction opposite to that of the pneumatic tire mounted on the right wheel on the front side are generated on the rear right wheel of the four-wheel vehicle. Mounting a pneumatic tire.

  In the method for mounting a pneumatic tire according to the present invention, the front left pneumatic tire and the front right pneumatic tire have the spiral grooves inclined in opposite directions, and the front tire The left wheel pneumatic tire and the rear left wheel pneumatic tire have the spiral grooves inclined in opposite directions, the front right pneumatic tire and the rear right wheel In the pneumatic tire, it is desirable that the direction of inclination of the spiral groove is opposite.

  The pneumatic tire of the present invention has a tread portion in which the rotation direction is specified, and the tire rotation shaft is inclined at the tread portion from the first tread end side to the second tread end side in the rotation direction. A spiral groove extending spirally around is provided. Such a spiral groove generates a lateral force in the tire axial direction from the first tread end side to the second tread end side when the pneumatic tire travels.

  Further, the spiral groove has a first groove wall on the first tread end side and a second groove wall on the second tread end side, and the tread method of the second groove wall from one end to the other end of the spiral groove. The inclination angle with respect to the line is formed larger than the inclination angle with respect to the tread normal line of the first groove wall. Such a spiral groove generates a lateral force in the tire axial direction from the first tread end side to the second tread end side due to a difference in rigidity between the first groove wall and the second groove wall at the time of ground contact. Therefore, the pneumatic tire of the present invention can generate a large lateral force.

  The pneumatic tire mounting method of the present invention is a step of mounting a pneumatic tire on a front left wheel and a front right wheel so that the generated lateral forces are opposite to each other in a four-wheel vehicle. And a step to install a pneumatic tire that generates lateral force in the direction opposite to that of the pneumatic tire mounted on the front left wheel on the rear left wheel, and a front right wheel on the rear right wheel Mounting a pneumatic tire that generates a lateral force in a direction opposite to that of the pneumatic tire. In a four-wheeled vehicle equipped with pneumatic tires in this way, for example, during straight traveling where the slip angle is zero, the lateral force acting on the front tire faces the outside of the vehicle and the lateral force acting on the rear tire When the force is directed toward the inside of the vehicle, the conicity forces of the front and rear wheels are offset. Further, since the lateral force acting on the front tire 1 is directed toward the outside of the vehicle, the reaction force against turning is slightly increased, so that excellent straight running stability performance is exhibited.

  Also, in a four-wheeled vehicle equipped with pneumatic tires as described above, for example, when running straight ahead where the slip angle is zero, the lateral force acting on the front tire is directed toward the inside of the vehicle and applied to the rear tire. When the acting lateral force is directed to the outside of the vehicle, the conicity forces of the front wheels and the rear wheels are offset. In addition, since the lateral force acting on the front tire is directed toward the inside of the vehicle, a steering force is generated with agility with respect to the steering wheel operation, so that excellent steering response performance is exhibited.

  In the tire of the present invention, the direction of inclination of the spiral groove coincides with the direction of lateral force acting on the tire. For this reason, even a general user can easily recognize the direction of the lateral force, so that the tire can be mounted so as to be set in a vehicle that is excellent in either straight running stability performance or steering response performance.

It is an expanded view of the tread part of the pneumatic tire of one embodiment of the present invention. It is the sectional view on the AA line of FIG. 1 is a schematic plan view of a four-wheeled vehicle showing an embodiment of a tire mounting method. It is a schematic plan view of the four-wheeled vehicle which shows other embodiment of the mounting method of a tire. It is an expanded view of the tread part of other embodiment. It is an expanded view of the tread part of other embodiment. It is sectional drawing of the pneumatic tire of other embodiment. It is a schematic plan view of a four-wheel vehicle equipped with a tire of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a development view of a tread portion 2 of a pneumatic tire 1 showing an embodiment of the present invention. A pneumatic tire (hereinafter sometimes simply referred to as “tire”) 1 of the present embodiment is suitably used as a tire for a four-wheeled vehicle such as a passenger car, for example. In the tire 1 of the present embodiment, the rotation direction N is designated. The rotation direction N is displayed with characters or the like on a sidewall portion (not shown), for example.

  As shown in FIG. 1, the tread portion 2 has a first tread end Te and a second tread end Ti. The first tread end Te and the second tread end Ti are flat on the tire 1 in a normal state in which the rim is assembled to the normal rim and the normal internal pressure is filled and the normal load is applied and the camber angle is 0 degree. It is defined as the ground contact position on the outermost side in the tire axial direction when grounded. In the present embodiment, the first tread end Te is displayed on the left side, and the second tread end Ti is displayed on the right side. In the normal state, the distance in the tire axial direction between the tread ends Te and Ti is determined as the tread contact width TW. Unless otherwise noted, the dimensions and the like of each part of the tire are values measured in a normal state.

  The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based. For example, “Standard Rim” for JATMA, “Design Rim” for TRA, ETRTO Then "Measuring Rim".

  “Regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. “JAMATA” is the “maximum air pressure”, TRA is the table “TIRE LOAD LIMITS” The maximum value described in “AT VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” in the case of ETRTO. When the tire is for a passenger car, the normal internal pressure is 180 kPa.

  “Regular load” is a load determined by each standard for each tire in the standard system including the standard on which the tire is based. “JATMA” indicates “maximum load capacity”, and TRA indicates “TIRE LOAD”. The maximum value described in “LIMITS AT VARIOUS COLD INFLATION PRESSURES”, “LOAD CAPACITY” in the case of ETRTO. When the tire is for a passenger car, the normal load is a load corresponding to 88% of the load.

  The tread portion 2 is provided with a spiral groove 3. The spiral groove 3 spirally extends around the tire rotation axis (not shown) so as to incline from the first tread end Te side to the second tread end Ti side in the rotation direction N. Such a spiral groove 3 generates a lateral force (conicity force) in the tire axial direction from the first tread end Te side to the second tread end Ti side during traveling even in a state where no slip angle is given.

  2 is a cross-sectional view taken along line AA in FIG. As shown in FIG. 2, the spiral groove 3 includes a first groove wall 4 on the first tread end Te side, a second groove wall 5 on the second tread end Ti side, a first groove wall 4 and a second groove. It has a groove bottom 6 between the wall 5.

  The first groove wall 4 and the second groove wall 5 extend inward in the tire radial direction from the tread surface 2 a of the tread portion 2. For example, the first groove wall 4 and the second groove wall 5 extend linearly from the tread surface 2a. The first groove wall 4 and the second groove wall 5 may be curved.

  In the spiral groove 3, from one end 3e to the other end 3i (shown in FIG. 1), the inclination angle β of the second groove wall 5 with respect to the tread normal line n2 is greater than the inclination angle α of the first groove wall 4 with respect to the tread normal line n1. Is also formed large. Such a spiral groove 3 has a difference in rigidity between the first groove wall 4 having a large rigidity and the second groove wall 5 having a small rigidity at the time of ground contact from the first tread end Te side to the second tread end Ti side. A lateral force in the tire axial direction is generated. Therefore, the tire 1 of the present invention can generate a large lateral force in the intended direction using the direction of the spiral of the groove and the angle of the groove wall even when the slip angle is zero. For this reason, the lateral force of each tire of a four-wheel vehicle can be canceled or combined by arranging the tires in any direction, for example, excellent straight running stability and handling response performance, etc. Or a vehicle having a large turning force toward one side can be set.

  The tread normals n1 and n2 are line segments perpendicular to the tread surface 2a at the intersections between the groove walls 4 and 5 and the tread portion 2a.

  The difference (β−α) between the inclination angle β of the second groove wall 5 and the inclination angle α of the first groove wall 4 is preferably 5 degrees or less. When the angle difference (β−α) exceeds 5 degrees, the rigidity difference between the first groove wall 4 and the second groove wall 5 becomes excessively large, and uneven wear is likely to occur. There is a risk that running performance will deteriorate. When the angle difference (β−α) is small, the lateral force may be small. For this reason, the angle difference (β−α) is more preferably 2 to 4 degrees.

  From the viewpoint of effectively exhibiting the above-described action, the inclination angle β of the second groove wall 5 is preferably 2 to 20 degrees.

  In the present embodiment, the inclination angle α of the first groove wall 4 and the inclination angle β of the second groove wall 5 are the same from one end 3e to the other end 3i. Thereby, the rigidity difference of the tread part 2 can be ensured small from the first tread end Te side to the second tread end Ti side. For this reason, for example, since uneven wear such as shoulder drop wear is suppressed, traveling performance is maintained high.

  As shown in FIG. 1, the spiral groove 3 of the present embodiment is linear in a developed view of the tread portion 2. Such a spiral groove 3 can ensure large rigidity of the tread portion 2 between the spiral grooves 3 and can generate a larger lateral force.

  In the present embodiment, the spiral groove 3 is formed as one continuous groove. Such a spiral groove 3 can ensure a smaller difference in rigidity of the tread portion 2 from the first tread end Te side to the second tread end Ti side.

  The angle θ1 of the spiral groove 3 with respect to the tire circumferential direction is preferably 3 to 20 degrees. When the angle θ1 of the spiral groove 3 is less than 3 degrees, the tire axial component of the spiral groove 3 is small, and the lateral force in the tire axial direction may be small. When the angle θ1 of the spiral groove 3 exceeds 20 degrees, the number of turns of the spiral groove 3 (four turns in the present embodiment) becomes small, and thus the lateral force may be reduced. The angle θ1 is more preferably 5 degrees or more.

  The groove width W1 of the spiral groove 3 is preferably 5 to 20 mm. When the groove width W1 of the spiral groove 3 is less than 5 mm, the first groove wall 4 and the second groove wall 5 are deformed so as to lean against each other during traveling, and apparently the first groove wall 4 and the second groove wall 5 There is a risk that the difference in rigidity may be reduced. When the groove width W1 of the spiral groove 3 exceeds 20 mm, the rigidity of the tread portion 2 tends to be small, and the running performance may be deteriorated. From the same viewpoint, the groove depth D1 (shown in FIG. 2) of the spiral groove 3 is preferably 5 to 10 mm.

  In the present embodiment, the tread portion 2 is not provided with a configuration having an edge component such as a groove or siping except for the spiral groove 3. Thereby, the rigidity difference of the tread part 2 is ensured further smaller.

  FIG. 3 shows a development view of the tread portion 2 of another embodiment of the present invention. As shown in FIG. 3, in this embodiment, the tread portion 2 includes a first region 11 in which the spiral groove 3 is provided, and an inclined groove 12 that is inclined in the same direction as the inclination of the spiral groove 3. And a plurality of second regions 13 provided therein. Such a tread portion 2 also generates a lateral force on one side in the tire axial direction because the spiral groove 3 and the inclined groove 12 have components in the tire axial direction and the inclination directions thereof are the same.

  In the present embodiment, the inclined groove 12 is formed as a lug groove that extends from the second tread end Ti inward in the tire axial direction and does not communicate with the spiral groove 3. The inclined groove 12 is not limited to such an embodiment, and may be a closed type lug groove whose both ends terminate in the tread portion 2.

  The width Wa in the tire axial direction of the second region 13 is preferably 25% to 50% of the tread contact width TW. Thereby, the lateral force generated by the second region 13 and the lateral force generated by the first region 11 are combined in a well-balanced manner, and a large lateral force is generated as the tire 1. The width Wa of the second region 13 is a length between both ends 12e and 12i of the inclined groove 12 in the tire axial direction.

  In the present embodiment, the first region 11 is provided on the first tread end Te side, and the second region 13 is provided on the second tread end Ti side. Note that the present invention is not limited to such an embodiment. For example, the first region 11 may be provided on the second tread end Ti side, and the second region 13 may be provided on the first tread end Te side (illustrated). (Omitted). Further, the first region 11 is provided at the center of the tread portion 2 including the tire equator C, and the second region 13 is provided at two locations on the first tread end Te side and the second tread end Ti side from the center portion. It is also possible to adopt a mode (not shown).

  As shown in FIG. 4, in this embodiment, the tread portion 2 is not provided with a groove other than the spiral groove 3 and the inclined groove 12. That is, the grooves provided in the tread portion 2 of this embodiment all have the same inclination direction. Therefore, a large lateral force is effectively generated.

  In order to effectively exhibit the above-described action, the groove width W2 of the inclined groove 12 is preferably 5 to 20 mm, for example. The groove depth (not shown) of the inclined groove 12 is preferably 5 to 15 mm, for example. The angle θ2 of the inclined groove 12 with respect to the tire axial direction is preferably 10 to 45 degrees, for example. In addition, it is desirable to provide 4 to 6 inclined grooves 12 with respect to the ground contact surface when the normal tire 1 is loaded with a normal load and grounded to a flat surface with a camber angle of 0 degree.

  FIG. 5 is another embodiment of the tread portion 2. FIG. 5 is a development view of the circumference of the tire in which the vertical axis indicates the angle in the tire circumferential direction and the horizontal axis indicates the tire axial direction. As shown in FIG. 5, the tread portion 2 is provided with a plurality of spiral grooves 3. Such a spiral groove 3 generates a large lateral force because the tire axial component increases. In the present embodiment, two spiral grooves 3a and 3b are provided. In order to effectively exhibit the above-described operation, it is desirable that two or three spiral grooves 3 are provided. The plurality of spiral grooves 3 desirably have the same inclination angle in order to ensure a large rigidity of the tread portion 2.

  FIG. 6 is a cross-sectional view of another embodiment of the spiral groove 3. As shown in FIG. 6, in this embodiment, from one end 3e to the other end 3i (shown in FIG. 1), the inclination angle α of the first groove wall 4 and the inclination angle β of the second groove wall 5 are Increasing gradually. Such a spiral groove 3 can generate a greater lateral force on the second tread end Ti side than on the first tread end Te side. For this reason, a larger lateral force can be generated as a whole of the tire 1 while ensuring a large rigidity on the first tread end Te side.

  Next, a method for mounting a tire having conicity on a four-wheel vehicle as in this embodiment will be described. FIG. 7 is a schematic plan view of the four-wheeled vehicle T on which the tire 1 provided with the spiral groove 3 of the present embodiment is mounted. As shown in FIG. 7, a four-wheeled vehicle (hereinafter may be simply referred to as “vehicle”) T has a front left wheel F1, a right wheel F2, a rear left wheel R1, and a right wheel R2. In the mounting method of the present embodiment, the first step of attaching the tire 1 to the front left wheel F1 and the front right wheel F2, the second step of attaching the tire 1 to the rear left wheel R1, and the rear right And a third step of attaching the tire 1 to the wheel R2. The traveling direction of the vehicle T is the direction D.

  In the first step, the tire 1 is attached to the front left wheel F1 and the front right wheel F2 so that the generated lateral forces are opposite to each other. Specifically, the tire 1 of the front left wheel F1 and the tire 1 of the front right wheel F2 are opposite in the direction of inclination of the spiral groove 3. More specifically, the spiral groove 3 of the tire 1 of the front left wheel F1 and the spiral groove 3 of the front right wheel F2 are both arranged in a direction inclined toward the vehicle outer direction in the rotational direction N.

  In the second step, the tire 1 that generates lateral force in the opposite direction to the tire 1 attached to the front left wheel F1 is attached to the rear left wheel R1. Specifically, the tire 1 of the front left wheel F1 and the tire 1 of the rear left wheel R1 are attached so that the spiral grooves 3 are inclined in opposite directions. In the present embodiment, the spiral groove 3 of the rear left wheel R1 is arranged in a direction inclined toward the vehicle inner side in the rotation direction N.

  In the third step, the tire 1 that generates lateral force in the opposite direction to the tire 1 attached to the front right wheel F2 is attached to the rear right wheel R2. Specifically, the tire 1 of the right wheel F2 on the front side and the tire 1 of the right wheel R2 on the rear side are attached so that the inclination direction of the spiral groove 3 is reversed. In the present embodiment, the spiral groove 3 of the right wheel R2 on the rear side is arranged in a direction inclined toward the vehicle inner side in the rotation direction N.

  In the vehicle T to which the tire 1 is attached in this manner, the lateral force acting on the front tire 1 is directed to the outer side of the left wheel F1 and the right wheel F2 when the vehicle is traveling straight with a slip angle of zero. Since the lateral force acting on the tire 1 faces both the left wheel R1 and the right wheel R2 toward the inside of the vehicle, the concentric forces of the front and rear wheels are offset. Further, since the lateral force acting on the front tire 1 is directed toward the outside of the vehicle, the reaction force against turning is slightly increased, so that excellent straight running stability performance is exhibited.

  FIG. 8 shows another embodiment of a vehicle T on which the tire 1 is mounted by the tire mounting method of the present embodiment. As shown in FIG. 8, in this vehicle T, the spiral groove 3 of the front left wheel F1 and the spiral groove 3 of the front right wheel F2 are both arranged in a direction inclined toward the vehicle inner side in the rotational direction N. . Further, the spiral groove 3 of the rear left wheel R1 and the spiral groove 3 of the rear right wheel R2 are arranged in a direction inclined toward the vehicle outer side in the rotational direction N. In the case of such a vehicle T, when traveling straight ahead with a slip angle of zero, the lateral force acting on the front tire 1 faces both the left wheel F1 and the right wheel F2 toward the inside of the vehicle and acts on the rear tire. Since the lateral force faces both the left wheel R1 and the right wheel R2 toward the outside of the vehicle, the consity forces of the front wheels and the rear wheels are offset. Further, since the lateral force acting on the front tire 1 is directed toward the inside of the vehicle, the steering force is generated with agility with respect to the steering operation, so that excellent steering response performance is exhibited.

  In the tire 1 of the present embodiment, the direction of the inclination of the spiral groove 3 and the direction of the lateral force acting on the tire 1 coincide with each other, so even a general user can easily recognize the direction of the lateral force. it can. Therefore, by adopting the tire mounting method of the present embodiment, a general user can set a vehicle that is excellent in either straight running stability performance or steering response performance.

  In addition, by mounting the tire 1 with the inclination of the spiral groove 3 in the same direction on all four wheels, for example, the vehicle can exhibit excellent straight running stability performance on a road surface provided with a cant.

  As mentioned above, although embodiment of this invention was explained in full detail, it cannot be overemphasized that this invention is not limited to illustrated embodiment, and can be deform | transformed and implemented in a various aspect.

A pneumatic tire for a passenger car of size 235 / 50R18 having the basic pattern of FIG. 1 or FIG. 3 and the spiral groove cross section of FIG. 2 was prototyped based on the specifications in Table 1, and the lateral force and steering stability performance of each sample tire And wet performance was tested. The main common specifications and test methods for each sample tire are as follows.
Groove depth of spiral groove: 8mm
Inclination angle β of the second groove wall: 10 degrees Width Wa / TW of the second region in the tire axial direction: 50%

<Side Force (Conicity Force)>
A lateral force variation (LFV) was measured using a tire uniformity testing machine in accordance with JASO C607: 2000 “Uniformity testing method for automobile tires”. Lateral force variation corresponds to the magnitude of lateral force. The results were expressed as an index with the average value of 20 sample tires determined and the value of Comparative Example 1 taken as 100. The larger the value, the better the lateral force.
Rims: 18x7JJ
Speed: 100km / h (high speed)
Internal pressure: 200kPa
Longitudinal load: 4.0kN

<Straight running stability and steering wheel response performance>
A test tire is mounted on a rear-wheel drive vehicle with a displacement of 3500 cc under the mounting conditions shown in FIGS. 6 and 7 and the following conditions, and a test driver places the vehicle on a test course on an asphalt road surface. The vehicle was run at a speed of 100 km / h, and the driving characteristics related to the straight-line stability at this time and the steering wheel response at the lane change were evaluated by the driver's sensuality. As a comparative example, the tire shown in FIG. 8 was also tested. The results are displayed in a 10-point method with 10 points being the perfect score. The larger the value, the better.
Rims: 18x7JJ
Internal pressure: 200kPa
Table 1 shows the test results.

  As a result of the test, it can be confirmed that the tire of the example has a greater lateral force than the tire of the comparative example. Further, the vehicle in which the sample tire is mounted by the tire mounting method of the example is superior in either the straight running stability performance or the steering response performance than the vehicle in which the sample tire is mounted by the tire mounting method of the comparative example. I can understand that. In addition, the same test was carried out by changing the tire size, but showed the same tendency as the test result. Furthermore, the tire having the cross section of FIG. 5 was also tested, and the same result as in this test was obtained.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 2 Tread part 3 Spiral groove 3e One end 3i Other end 4 1st groove wall 5 2nd groove wall (alpha) The inclination angle of 1st groove wall (beta) The inclination angle of 2nd groove wall N Rotation direction Te 1st tread edge Ti Second tread end

Claims (5)

A pneumatic tire having a tread portion with a specified rotation direction,
A spiral groove extending spirally around the tire rotation axis is provided in the tread portion so as to be inclined from the first tread end side to the second tread end side in the rotation direction,
The spiral groove has a first groove wall on the first tread end side and a second groove wall on the second tread end side,
A pneumatic tire characterized in that, from one end to the other end of the spiral groove, an inclination angle of the second groove wall with respect to a tread normal line is larger than an inclination angle of the first groove wall with respect to a tread normal line.   The pneumatic tire according to claim 1, wherein a difference between the inclination angle of the first groove wall and the inclination angle of the second groove wall is 5 degrees or less. The tread portion includes a first region in which the spiral groove is provided;
The pneumatic tire according to claim 1 or 2, including a second region in which a plurality of inclined grooves that are inclined in the same direction as the inclination of the spiral groove are provided in the tire circumferential direction. A method for mounting the pneumatic tire according to any one of claims 1 to 3 on a four-wheel vehicle,
In the four-wheel vehicle, attaching a pneumatic tire to the front left wheel and the front right wheel so that the generated lateral forces are opposite to each other;
Attaching a pneumatic tire that generates lateral force in a direction opposite to that of the pneumatic tire mounted on the front left wheel to the rear left wheel of the four-wheel vehicle;
Mounting a pneumatic tire that generates a lateral force in a direction opposite to that of the pneumatic tire mounted on the front right wheel on the rear right wheel of the four-wheel vehicle. How to put in tires. In the front left pneumatic tire and the front right pneumatic tire, the direction of inclination of the spiral groove is opposite,
In the front left pneumatic tire and the rear left pneumatic tire, the direction of the inclination of the spiral groove is opposite,
The method for mounting a pneumatic tire according to claim 4, wherein the front right-hand pneumatic tire and the rear right-hand pneumatic tire have the spiral grooves inclined in opposite directions.

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