JP2013035449A - Tire mounting structure of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a tire to be used in all seasons, in summer and winter, configured to have effective summer performance in one lateral side area of a tread part and effective winter performance in the other side area.SOLUTION: The tire 10 includes three or more peripheral directional grooves 12 formed in the tread part 11, and a land part 13 divided by the peripheral directional grooves 12, and is configured to have effective summer performance in the one lateral side area 11a and configured to have effect in the winter performance in the other side area 11b. A driving wheel-side tire 10 is installed with the side of the area 11a having the effective summer performance facing the vehicle outside, and a driven wheel-side tire 10 is installed with the side of the area 11b having the effective winter performance facing the vehicle outside.

Description

  The present invention relates to a tire mounting structure for a vehicle in which the same type of tire is mounted on a driving wheel and a driven wheel.

  Conventionally, tires of vehicles (automobiles) such as passenger cars are generally the same tires regardless of whether they are on the driving wheel side or driven wheel side, but they run on snowy and frozen road surfaces in winter. Tires suitable for driving, that is, winter tires that excel in winter performance, and summer tires that excel in performance during normal summer roads, such as roads and highways without snow and freezing, that is, summer tires that excel in summer performance In general, summer tires are usually worn during the summer season, and in winter when there is a risk of running on snowy road surfaces or frozen road surfaces, the tires are generally replaced with winter tires.

  However, in order to replace the summer tire and the winter tire, the user must purchase two types of tires for winter and summer and store one of the tires. In addition, the troublesome replacement work as described above is also required. Also, in areas where there is almost no snow even in winter, it is normal to wear tires for summer all year, so it is difficult to run when it snows occasionally, so you can switch to other means of transportation than cars Sometimes, tires for winter are unavoidably purchased.

  In order to solve the above problems, for example, by devising the configuration of the tread part and the mounting form on the vehicle, etc., both the summer performance and the winter performance can be exhibited, and the same tire can be used throughout the summer and winter. Tires that can run all year are desired.

  The tire mounted on the vehicle has a greater contribution to the performance of the tire in the region located on the outer side of the region of the tread portion of the circumferential surface. Therefore, the configuration of the tread portion is defined as one side in the width direction. It has been proposed to use different tires on the other side and change the direction of the tires depending on the mounting position with respect to the front wheels and the rear wheels, thereby making the performance exhibited by the tires different.

  For example, in Patent Document 1, in a truck or a bus, for the purpose of sufficiently exerting the functions of the front wheel and the rear wheel, a portion on one side of the tire circumferential surface is larger in rigidity than the other side and excellent in uneven wear resistance, Use a tire with a portion with excellent driving performance and braking performance on the other side, such as a tire with an asymmetrical pattern with different patterns. In this case, two tires are used as double wheels, and a portion having excellent rigidity against uneven wear is positioned on the adjacent side of both tires, and a portion having excellent driving performance and braking performance is positioned outside the vehicle. It has been proposed to be mounted on.

  However, this proposal takes into account the functionality of uneven wear resistance of the front wheels, which is heavily loaded on the outside of the vehicle when turning, and the functionality of driving and braking performance of the rear wheels. It does not achieve both winter performance and is therefore not intended to eliminate the replacement of summer tires and winter tires.

  Further, Patent Document 2 uses a tire in which the tire tread has an asymmetric pattern when new and wears a point-symmetric pattern centered on the tire equator when worn, and when the tire tread becomes a point-symmetric pattern, the tire is mounted. It has been shown that by rotating without changing the direction of the tire, uneven wear of the tire is corrected.

  However, as in the prior art, the one of Patent Document 2 is used by attaching the same pattern side of the tread portion to the outer side of the vehicle on both the front and rear wheels and all the tires of the driving wheel and the driven wheel. However, it is not intended to achieve both summer performance and winter performance. In winter, it is necessary to replace the summer tire with the winter tire.

Japanese Patent Laid-Open No. 10-71810 JP 2008-260423 A

  The present invention has been made in view of the above, and in a structure in which one type of tire of the same shape is mounted on a driving wheel that exhibits traction of a vehicle and a driven wheel that does not exhibit traction, By changing the direction, it is possible to provide both a summer performance and a winter performance, and provide a vehicle tire mounting structure that can be used throughout the season without requiring tire replacement.

  The present invention relates to a tire mounting structure for a vehicle in which the same type of tire is mounted on one of the front and rear driving wheels and the other driven wheel of the vehicle, the tread portion having three or more circumferential grooves, and the circumferential direction. Using a tire having a land portion defined by a groove, a structure in which the region on one side in the width direction of the tread portion is effective for summer performance, and a region on the other side is effective for winter performance, The tire on the driving wheel side is mounted with the side having the configuration effective for the summer performance outside the vehicle, and the tire on the driven wheel side is mounted with the side having the configuration effective for the winter performance set on the vehicle outside. It is characterized by becoming.

  According to the tire mounting structure of the present invention, the drive wheel side can sufficiently exhibit traction, and by mounting with the side having a configuration effective for summer performance on the outside of the vehicle, uneven wear of the tire can be prevented. In addition, it is possible to ensure steering stability on a normal DRY road surface and a WET road surface. In addition, the driven wheel side is less likely to have traction than the drive wheel side, so it can be mounted on the outside of the vehicle with a configuration that is effective for winter performance to drive on snowy road surfaces, frozen road surfaces, etc. Winter performance such as drivability and braking performance can be secured. Therefore, both summer performance and winter performance can be achieved, and it can be used throughout the season regardless of whether it is summer or winter.

  In the tire mounting structure of the vehicle, the tread pattern of the tire includes at least an outermost first row on the one side in the width direction and a next second row among land portions defined by circumferential grooves in the tread portion. A summer-oriented pattern in which the region including the land part is effective for summer performance, and the winter direction in which the region including the land part in the outermost first row and the next second row on the other side is effective for winter performance. It shall be a pattern.

  In the tire mounting structure of the vehicle described above, sipes are respectively formed on the land portion of the summer-oriented pattern and the land portion of the winter-oriented pattern in the tread portion of the tire, the sipe of the summer-oriented pattern is straight, and the sipe of the winter-oriented pattern is It shall be wavy. In addition, the sipe density of the summer-oriented pattern may be set smaller than the sipe density of the winter-oriented pattern.

  In the tire mounting structure of the vehicle, the void ratio of the summer pattern in the tread portion of the tire is the same as or larger than the void ratio of the winter pattern, and the see-through void ratio of the summer pattern is that of the winter pattern. A ratio larger than the see-through void ratio is preferable from the viewpoint of hydroplaning performance and steering stability when traveling on a WET road surface.

  In the tire mounting structure of the vehicle, the summer-oriented pattern of the tire is a pattern based on a rib structure in which at least one row of land portions defined by circumferential grooves is continuous in the circumferential direction, and a winter-oriented pattern is in the circumferential direction. It is assumed that the pattern is based on a block structure in which a land portion defined by a groove is divided by a horizontal groove and is intermittent in the circumferential direction.

  In the vehicle tire mounting structure, the tread portion of the tire has four or more circumferential grooves, and the summer pattern includes the outermost land portion on one side in the width direction to the third row land portion. An area can be set. Alternatively, the winter pattern can be set to an area including the outermost land portion on the other side in the width direction to the land portion in the third row.

  In the tire mounting structure of the vehicle, the region of the summer pattern and the region of the winter pattern in the tread portion of the tire are formed of the same rubber material, the rubber hardness at normal temperature is 60 to 80 degrees, and the embrittlement temperature is The viscoelasticity Tα can be −50 ° C. to −30 ° C.

  In the tire mounting structure for a vehicle described above, a region on one side in the width direction in the tread portion of the tire and a region effective on winter performance on the other side in the width direction are formed of two types of rubber materials having different physical properties. The one side region is effective for summer performance by setting the rubber hardness of one region and tan δ (loss tangent) at 35 ° C. higher than the rubber hardness and tan δ of the other region. The other side region can be configured to be effective for winter performance.

  Here, tan δ at 35 ° C. defined in the present invention is obtained by using a viscoelastic spectrometer manufactured by UBM Co., Ltd., with a vulcanization temperature of 183 ° C. and a vulcanization time of 10 minutes, width 5 mm × thickness 1 mm × A sample with a length of 20 mm is a value measured at a temperature of 35 ° C. under conditions of a frequency of 10 Hz, a static strain of 10%, and a dynamic strain of 1%.

  The viscoelasticity Tα defined in the present invention is defined as Tα at a temperature (° C.) at which tan δ reaches a peak under the same measurement conditions as tan δ. The embrittlement temperature is a temperature measured according to JIS K 6261.

  In the tire mounting structure for a vehicle described above, an interface between a rubber material in a region effective in summer performance on one side in the width direction in the tread portion and a rubber material in a region effective in winter performance on the other side in the width direction is one. Near the two circumferential grooves and inclined laterally with respect to the plane perpendicular to the tread surface, and the bottom surfaces of the lateral groove portions extending laterally from the one circumferential groove are formed of the two rubber materials. It is preferable to incline along the interface.

  In the tire mounting structure of the vehicle described above, an indication indicating which side is on the side of the region effective for summer performance and the side surface of the region effective for winter performance is attached, Based on this indication, the drive wheel side is mounted with the region effective for summer performance on the outside of the vehicle, and the driven wheel side is mounted with the region effective for winter performance on the vehicle exterior. be able to.

  As described above, according to the tire mounting structure for a vehicle of the present invention, the driving wheel side is mounted with the side having a configuration effective for the summer performance in the tire tread portion on the outside of the vehicle. Performance suitable for traveling on highways and traveling on WET roads can be demonstrated. Further, on the driven wheel side, the performance required for winter tires such as running on a snowy road surface can be secured by mounting the side having a configuration effective for winter performance on the outside of the vehicle.

  Therefore, with tires attached to the driving wheels and driven wheels of the vehicle, both summer performance and winter performance can be achieved, and it can be used throughout the season regardless of whether it is summer or winter. The accompanying tire change can be made unnecessary. Therefore, it is not necessary to hold two types of tires, a summer tire and a winter tire, and a space for storing a spare tire is not required.

1 is a schematic plan view showing an embodiment of a vehicle tire mounting structure according to the present invention. It is a partial schematic plan view showing an example of a peripheral surface of a tire used in the tire mounting structure of the present invention. It is sectional drawing of a tire same as the above. FIG. 6 is a schematic plan view showing another example of a tire peripheral surface used in the tire mounting structure of the present invention. FIG. 6 is a schematic plan view showing another example of a tire peripheral surface used in the tire mounting structure of the present invention. FIG. 6 is a schematic plan view showing another example of a tire peripheral surface used in the tire mounting structure of the present invention. FIG. 6 is a schematic plan view showing another example of a tire peripheral surface used in the tire mounting structure of the present invention. It is sectional drawing of the tire of another Example. It is a partial expanded sectional view of FIG. It is a partial enlarged side view of a tire. 6 is a schematic plan view of a tire peripheral surface used in a tire mounting structure of Comparative Example 4. FIG.

  Next, embodiments of the present invention will be described based on examples shown in the drawings.

  The tire 10 used in the tire mounting structure according to the present invention is basically configured in the same manner as a conventional tire. For example, as illustrated in the cross-sectional view of FIG. 3, the inner liner 1, the tread rubber 2, and the sidewall 3 are mainly used. Are combined with tire reinforcing members including cords such as the carcass layer 4 and the belt layer 5. Reference numeral 6 in the figure denotes a bead portion including a bead core 7.

  As shown in FIGS. 2 and 4 to 7, the tread portion 11 made of the tread rubber 2 on the tire circumferential surface includes three or more circumferential grooves 12 extending in the tire circumferential direction, There are four or more rows of land portions 13 defined by the directional grooves 12, and the land portions 13 are formed by rib structures that are continuous in the tire circumferential direction, or by lateral grooves 14 that obliquely intersect the circumferential grooves 12, for example. A tread pattern having a block structure that is divided into blocks and intermittent in the circumferential direction or a combination of these is formed. Usually, each land portion 13 is formed with sipes 16, 17 made of narrow grooves having a groove width of 1.5 mm or less.

  In particular, in the tire 10 used in the present invention, a predetermined area in the ground contact surface on one side in the width direction of the tread portion 11 is effective in summer performance, that is, steering stability and resistance to unevenness on the DRY road surface and the WET road surface. It has a structure that emphasizes wearability and other summer performances, and a predetermined area in the ground contact surface on the other side in the width direction has an effect on winter performances, that is, driving performance and braking performance when driving on snowy road surfaces and other winter performances. It is set to make an important configuration. The symbol W in the figure indicates the contact surface equivalent width, 11a indicates a region effective for summer performance, and 11b indicates a region effective for winter performance.

  In order to make a difference in the performance of both the regions 11a and 11b as the region 11a effective in summer performance on one side in the width direction and the region 11b effective in winter performance on the other side, for example, a tread pattern is used. The regions 11a and 11b may be configured differently, or the tread rubber 2 of the tread portion 11 may be configured using two types of rubber materials having different physical properties in the regions 11a and 11b. Further, the different pattern configuration and the use of two kinds of rubber materials having different physical properties can be used in combination.

In the case where the tread pattern has a different pattern configuration in the regions 11a and 11b, the region 11a including at least the outermost first row on the one side in the width direction of the tread portion 11 and the land portion 13 of the next second row is formed in the summer season. A summer-oriented pattern having a configuration effective in performance, and a region 11b including at least the outermost first row and the next second row of land portions 13 on the other side in the width direction is used for winter in a configuration effective in winter performance. A pattern is set, and for example, one or both of the shape and density of the sipe are different between the regions 11a and 11b.
That is, as shown in FIGS. 2, 4, 5, and 7 to be described later, a straight sipe 16 is formed on the land portion 13 of the region 11a on the one side on the summer pattern side, so that it is suitable for winter. A wavy sipe 17 is formed in the region 11b on the other side of the pattern, and the sipe density of the winter pattern is made higher than the sipe density of the summer pattern, thereby making the patterns different in the regions 11a and 11b. . When the sipe shape is straight, it is suitable for summer patterns due to the drainage effect when driving on the WET road surface compared to the wave shape, and when the sipe shape is wavy, the grip property on the snowy road surface is compared with the straight shape. High and suitable for winter patterns. As will be described later, a higher sipe density is suitable for a winter pattern and a lower sipe density for a summer pattern.

  The straight sipe 16 and the wavy sipe 17 may be refracted at a required portion in the length direction or may be curved in the length direction. A sipe having a groove portion extending in a straight line is made into a wave shape, and a sipe without a wave-like portion is made into a straight shape.

  Moreover, apart from making the shapes and densities of the sipes 16 and 17 different as described above, for example, as in the embodiments of FIGS. 2, 4, 5 and 6 described later, The region 11a on one side in the width direction is a pattern in which at least one row of land portions 13 in the region 11a is continuous in the circumferential direction, that is, a pattern based on a rib structure, and the region 11b on the other side in the width direction is the region A pattern in which the land portion 13 in 11b is divided into a block shape by, for example, a transverse groove 14 that obliquely intersects the circumferential groove 12, that is, a pattern based on a block structure, may be used.

  In particular, the pattern configuration different between the two regions 11a and 11b may be only the difference in the shape and density of the sipes 16 and 17, or only the difference in the land shape between the rib structure and the block structure. As shown in FIGS. 2, 4, and 5, it is desirable to set a summer-oriented pattern and a winter-oriented pattern by using a difference in sipe shape, density, etc., and a rib structure or block structure in combination.

  In the embodiment of FIG. 2, the tread portion 11 of the tire 10 has three circumferential grooves 12 and four rows of land portions 13 (13a, 13b) defined by the circumferential grooves 12, A region 11a including the outermost land portion 13a on the one side in the width direction of the tread portion 11 and the next second row of land portions 13a is formed with straight sipes 16 on both land portions 13a in the region 11a. Thus, a region 11b that is set as a summer-oriented pattern effective in summer performance and includes the outermost land portion 13b on the other side in the width direction of the tread portion 11 and the next second row of land portions 13b, A wavy sipe 17 is formed in both land portions 13b in the region 11b, and the sipe density is higher than that of the straight sipe 16, so that a winter-oriented pattern effective in winter performance is set. Further, the region 11a on the one side has a pattern based on a rib structure in which the second row of land portions 13a are continuous in the circumferential direction, and the outermost land portion 13a is divided by the lateral groove 14a and interrupted. I am doing. The region 11b on the other side has a pattern based on a block structure in which the land portions 13b are divided into blocks by the lateral grooves 14 and intermittent in the circumferential direction.

  The circumferential groove 12 of the tread portion 11 is not necessarily a groove having a relatively large groove width extending linearly in the tire circumferential direction, but a groove extending in a zigzag shape in the tire circumferential direction, or another circumferential groove. The groove may be a straight line or a zigzag shape that is slightly narrower than the groove.

  In the embodiment of FIG. 4, the tread portion 11 includes four circumferential grooves 12, 12c including a slightly narrow groove 12c extending in the circumferential direction in a zigzag shape, and the circumferential grooves 12, 12c. It has five rows of land portions 13 (13a, 13b, 13c) defined by And the area | region 11a including the land part 13c of the 3rd row | line | column from the outermost land part 13a of the width direction one side of the tread part 11 has the straight sipe 16 in the land parts 13a and 13c in this area | region 11a. By being formed, a region 11b that is set as a summer-oriented pattern effective for summer performance and includes the remaining outermost land portion 13b on the other side in the width direction and the next second row of land portions 13b is the region 11b. A wave-shaped sipe 17 is formed in the land portion 13b, and the sipe density is set higher than that of the straight sipe 16, so that it is set as a winter-oriented pattern effective in winter performance. Further, the region 11a on the one side has a pattern based on a rib structure in which the second row of land portions 13a are continuous in the circumferential direction, and the outermost land portion 13a and the third row of land portions 13c are lateral grooves. The pattern is divided by 14a and 14c. The region 11b on the other side has a pattern based on a block structure in which the land portions 13b are divided into blocks by the lateral grooves 14 and intermittent in the circumferential direction.

  In the case of the embodiment of FIG. 5, the tread portion 11 includes four circumferential grooves 12, 12c including a slightly narrow groove 12c similar to the above, and five rows defined by the circumferential grooves 12, 12c. The land portion 13 (13a, 13c, 13b) is included. Then, the outermost land portion 13a on the one side in the width direction of the tread portion 11 and the region 11a of the land portion 13a in the second row form a straight sipe 16 on the land portion 13a in the region 11a. The region 11b, which is set as a summer-oriented pattern effective for summer performance and includes the remaining outermost land portion 13b on the other side in the width direction to the third row land portion 13c, is a land portion 13b in the region 11b. , 13c, and a sipe density higher than that of the straight sipe 16 is set as a winter-oriented pattern effective in winter performance. Further, the region 11a on the one side has a pattern in which the land portions 13a in the second row are continuously formed in a rib shape in the circumferential direction and based on a rib structure, and the outermost land portion 13a has a second lateral groove 14a. The pattern is divided and interrupted. The region 11b on the other side has a pattern based on a block structure in which the land portions 13b and 13c are divided into blocks by the lateral grooves 14 and 14c and are interrupted in the circumferential direction.

  In the embodiment described above, the difference between the sipe shape and the density and the difference in the land portion shape are used together as the summer-oriented pattern of the region 11a on the one side in the width direction of the tread portion 11 and the winter-oriented pattern on the region 11b on the other side in the width direction. In addition, the summer-oriented pattern and the winter-oriented pattern can be set only by the difference in the sipe shape and density, or the difference in the land shape.

  For example, in the embodiment of FIG. 6, as in the embodiment of FIG. 2, in the case of having three circumferential grooves 12 and four rows of land portions 13 (13 a, 13 b), one side in the width direction of the tread portion 11. The region 11a on the side has a summer-oriented pattern based on a rib structure that is effective for summer performance by continuing the second row of land portions 13a in a rib shape in the tire circumferential direction, and the region 11b on the other side. The inner land portions 13b are divided into blocks by the lateral grooves 14 and are intermittently connected in the circumferential direction to form a winter pattern based on a block structure that is effective for winter performance. The land portions 13 (13a, 13b) of both the regions 11a, 11b are both formed with a straight sipe 16, but the sipe density of the region 11b on the other side of the winter pattern is the summer pattern. Is higher than the sipe density of the region 11a on the one side.

  In the case of the embodiment of FIG. 7, as in the embodiment of FIG. 2, one having one circumferential direction groove 12 and four rows of land portions 13 (13 a, 13 b) in the width direction of the tread portion 11. The region 11a and the region 11b on the other side in the width direction have a block structure pattern in which the land portions 13a and 13b are point-symmetric on the left and right, and the shapes of the sipes 16 and 17 formed on the land portions 13a and 13b By making it straight in the region 11a on one side, a summer-oriented pattern effective in summer performance, and making it wavy in the region 11b on the other side, and by making its sipe density higher than the region 11a on the one side The case where it sets as a winter direction pattern is shown. Thus, even in the case of a bilaterally symmetric pattern or a point symmetric pattern due to the rib structure or block structure, the difference in shape and density between the straight sipe 16 and the waved sipe 17 can be changed in the summer. The winter performance can be varied.

  In practice, the shape of the land portion 13 defined by the circumferential groove 12 as described above is changed to a pattern based on the rib structure and a pattern based on the block structure, and the sipe 16 formed on each land portion, It is more preferable that the shape of 17 is straight and wavy, and that the sipe density is different, so that the summer performance and the winter performance can be reliably expressed.

  The summer pattern may be any pattern shape as long as it is effective for summer performance.

  That is, when the summer-oriented pattern is a pattern based on the rib structure, it is not necessary that all the land portions 13 in the region of the summer-oriented pattern have a rib structure that is completely continuous in the tire circumferential direction. As long as one row of land portions 13 has a rib structure that is continuous in the tire circumferential direction, the other land portions may be substantially intermittent by a lateral groove or the like. For example, in the case of each of the embodiments shown in FIGS. 2 and 4 to 6 described above, a rib structure in which the second row of land portions 13a is continuous in the circumferential direction from the outermost side in the region 11a on one side in the width direction is used. The outer land portion 13a is divided by the transverse groove 14a to form an intermittent pattern. In some cases, the land portion 13a may be substantially continuous in the tire circumferential direction by forming a part of the groove portion 14a-1 of the lateral groove 14a as a groove having the same width as the sipe or a shallow groove. Further, the land portions 13c in the third row in FIG. 4 are in the form of blocks that are divided in the circumferential direction by being divided by a lateral groove 14c that is refracted at the center in the width direction of the land portion.

  In the present invention, the land divided only by the narrow groove sipe 16 from the outermost side of the region 11a in the pattern of FIGS. 2, 4, 5 and 6 as in the second row land portion 13a. The part has a rib structure that is substantially continuous in the circumferential direction.

  In addition, as the winter pattern, any pattern shape may be used as long as the pattern is effective in winter performance, but in practice, when the summer pattern is a pattern based on a rib structure, It is preferable that all the land portions 13 in the winter-oriented pattern region 11b have a block structure that is intermittent in the tire circumferential direction. In the case of forming a wavy sipe 17 in each land portion as a winter-oriented pattern and increasing the sipe density to have a pattern configuration effective for winter performance, the land portion is not necessarily a block structure. However, although some land portions may have a rib structure, in practice, it is preferable that all land portions have a block structure as shown in the figure.

As described above, the sipe density of the winter pattern is higher than the sipe density of the summer pattern, in other words, the sipe density of the summer pattern, as described above. The density is preferably set to be smaller than the sipe density of the winter pattern. The sipe density of the summer pattern is set to 40 to 80 (index) with respect to the sipe density 100 of the winter pattern. For example, with respect to the sipe density 0.080~0.010 (mm / mm ²⁾ of the summery pattern is preferably set to a sipe density of winter use pattern 0.050~0.130 (mm / mm ^2). That is, for the sipe 16 with a winter pattern, it is better to increase the sipe density in order to ensure winter performance such as grip when traveling on a snowy road surface. In the case of a summer pattern, rigidity is maintained and uneven wear is prevented. In order to maintain the performance when traveling on a normal road surface such as the above, it is better to lower the sipe density, so it is preferable to set the sipe density as described above.

  Further, regarding the configuration of the circumferential groove 12 of the tread portion 11, a void ratio indicating a ratio of the circumferential groove to the ground contact area in the pattern region, and a land portion when the circumferential groove is viewed in the tire circumferential direction. For the see-through void ratio, which indicates the ratio of non-existent, the void ratio of the summer pattern is the same as or larger than the void ratio of the winter pattern, and the see-through void ratio of the summer pattern is It is preferable that the ratio be greater than the see-through void ratio of the pattern. Therefore, the void ratio of the summer pattern is 100 to 120 (index) with respect to the void ratio 100 of the winter pattern, and the see-through void ratio of the summer pattern is 130 to 250 with respect to the see-through void ratio 100 of the winter pattern. (Index). For example, when the void ratio of the winter pattern is 25.0 to 38.0% and the see-through void ratio is 8.5 to 16.0%, the void ratio of the summer pattern is 25.0 to 43.0%, The see-through void ratio is 18.4 to 34.5%. As a result, it is possible to ensure drainage when traveling on a wet road surface such as a normal road surface or a highway without snow.

  The void ratio and the see-through void ratio can be easily set depending on whether the pattern is based on a rib structure or a pattern based on a block structure, as shown in the figure.

  As the rubber material of the tread portion 12 for setting the summer-oriented pattern and the winter-oriented pattern, a rubber material similar to the conventional one can be used. For example, as rubber material, rubber hardness at normal temperature as a vulcanized tire (according to JIS K 6253, at 23 ° C. for a sample vulcanized at a heating temperature of 183 ° C. and a vulcanization time of 10 minutes, The rubber hardness measured using a type A durometer is 60 to 80 degrees, preferably 65 to 75 degrees, the embrittlement temperature (JIS K 6261) is −50 ° C. or less, and tan δ is measured under the same measurement conditions as tan δ below. A rubber material having a physical property in which the viscoelasticity Tα indicated by the temperature at which the peak value reaches -50 ° C to -30 ° C is preferably used.

  When the summer-oriented pattern and the winter-oriented pattern regions 11a and 11b are set as described above, and the performances of both the regions 11a and 11b are different depending on the pattern, the regions 11a and 11b as shown in FIG. One kind of rubber material can be used, or two kinds of rubber materials having different physical properties can be used for both regions 11a and 11b as shown in FIG.

  That is, as described above, when a summer-oriented pattern is set in the region 11a on one side in the width direction of the tread portion 11 and a winter-oriented pattern is set in the region 11b on the other side, the region effective in summer performance as shown in FIG. 11a and the region 11b effective in winter performance, using different rubber materials, the physical properties of both the regions 11a and 11b, particularly the rubber hardness (JIS K 6253 A), and tan δ (loss tangent at 35 ° C.) It is preferable that the rubber hardness and tan δ on the side of the region 11a effective for summer performance are made higher than those of the region 11b effective for winter performance, respectively. For example, the rubber hardness of the region 11b effective for winter performance is 46 to 68 degrees, and the width obtained at a vulcanization temperature of 183 ° C. and a vulcanization time of 10 minutes using a viscoelastic spectrometer manufactured by UBM Co., Ltd. For a sample of 5 mm × thickness 1 mm × length 20 mm, tan δ measured at a temperature of 35 ° C under the conditions of a frequency of 10 Hz, a static strain of 10%, and a dynamic strain of 1% is 0.240 to 0.265, which is effective for summer performance. The rubber hardness of the region 11a on the side of the surface is 60 to 75 degrees, and tan δ is 0.266 to 0.285.

  Thus, by using materials having different physical properties as the rubber material of both the regions 11a and 11b, the summer performance is further enhanced in the summer-oriented region 11a in combination with the summer-oriented pattern, and the winter-oriented region 11b. Then, combined with the winter pattern, winter performance is further enhanced.

  When using the rubber materials having different physical properties such as the rubber hardness and tan δ, the tread pattern is not necessarily the same as the summer-oriented pattern and the winter region on one side and the other side in the width direction as in the illustrated embodiment. For example, in a laterally symmetrical pattern or an asymmetric pattern that is not divided into orientation patterns, a rubber material having physical properties is used in one region in the width direction and another region in the width direction. By making tanδ different, it is also possible to express the effects of summer performance and winter performance, respectively. In practice, as described above, it is preferable that the summer-oriented pattern and the winter-oriented pattern are set and the rubber material is further different as described above.

  As described above, when two types of rubber materials having different physical properties are used for, for example, a summer-oriented pattern region 11a effective in summer performance and a winter-oriented pattern region 11b effective in winter performance, The interface of the rubber material is in the vicinity of one circumferential groove 12 (12c), and is inclined laterally with respect to a plane perpendicular to the surface of the tread portion 11. In this case, as shown in FIG. 9, the bottom surface of the lateral groove portion 14c (or 14b) extending laterally from the one circumferential groove 12c (or 12) and terminating is inclined along the interface between the two rubber materials. It is preferable to suppress the undulation at the interface of the rubber material having different physical properties and ensure the uniformity of the tire.

  In the vehicle tire mounting structure of the present invention, as described above, the region 11a on the one side in the width direction of the tread portion is effective in summer performance, for example, a summer-facing pattern in which sipes are straight as shown in the figure, and / or A summer-oriented pattern based on a rib structure is formed, and the region 11b on the other side in the width direction is based on a configuration effective for winter performance, for example, a winter-oriented pattern having a sipe wave shape and / or a block structure as shown in the figure. One type of tire 10 having the same shape and having a winter pattern is arranged and used at all tire mounting positions of the vehicle.

  1 shows, for example, the same shape of the tire 10 having the tread pattern shown in FIG. 4 on the driving wheel side (front wheel) and the driven wheel side (rear wheel) in the front-wheel drive FF vehicle, respectively, in different directions inside and outside the vehicle. It shows the case of mounting. The tire 10 having the same shape of the tread pattern shown in FIG. 2, FIG. 5, FIG. 6, and FIG.

  That is, the tire 10 is placed on the wheel axle 21 on the drive wheel side with the region 11a effective in summer performance on one side in the width direction of the tread portion 11 mainly facing the region 11a of the summer-oriented pattern toward the outside of the vehicle. The tire 10 is mounted on the wheel axle 22 on the driven wheel side, with the region 11a effective for summer performance on the inside, and the region 11b effective for winter performance on the other side in the width direction. The region 11b of the winter pattern is mounted with the vehicle facing outward.

  The tires mounted on the drive wheel side and the driven wheel side are the same in the rear-wheel drive FR vehicle. On the drive wheel side, for example, the region of the summer-oriented pattern that is effective for summer performance is set on the vehicle outer side. The tire is mounted on the driven wheel side, for example, with the winter pattern side having an effect on winter performance on the outside of the vehicle. Further, in the case of a front-wheel drive vehicle, all the drive wheels may be fitted with tires with the region having an effect on summer performance in the same manner as described above.

  In order to facilitate a work operation for mounting the same tire 10 in a different direction, as shown in FIG. 10, for example, the region 11a side of the summer-oriented pattern that is effective in summer performance and / or winter performance For example, on the side of the tire on the side of the region 11b of the winter-oriented pattern, which indicates which side is the outer side of the driving wheel or the outer side of the driven wheel, for example, “DRIVE SIDE / It is preferable to provide signs 18 such as characters, figures, symbols, etc. such as “NODRIVE SIDE” and / or “SUMMER SIDE / WINTER SIDE”. Thereby, when the tire 10 is attached to and mounted on the wheel axle of the vehicle, it can be easily confirmed whether it is the outer side of the driving wheel or the outer side of the driven wheel, and the mounting operation can be facilitated.

  As described above, the tire mounting direction is different between the driving wheel side and the driven wheel side of the vehicle, and on the driving wheel side that can exhibit traction, the region 11a that is effective in summer performance is mounted with the side outside the vehicle. As a result, it is possible to ensure steering stability during driving on a DRY road surface or a WET road surface particularly on ordinary roads and highways, and to exhibit performance required in summer. In addition, on the driven wheel side where it is difficult to obtain traction with respect to the driving wheel, the driving performance and braking performance can be secured by attaching the region 11b effective for winter performance to the outside of the vehicle, and the snowy road surface can be secured. It can demonstrate winter performance such as snow performance required when traveling. That is, the vehicle as a whole can achieve both summer performance and winter performance, and can be used throughout the season regardless of whether it is summer or winter, and it is not necessary to hold two types of tires for summer and winter. This eliminates the need for tire replacement.

  Hereinafter, in a domestic FF vehicle (compact car with a displacement of 1300 cc class), when the tire mounting structure of the present invention is applied (Examples 1 to 8) and according to a conventional tire mounting structure (Comparative Examples 1 to 4) ) And the following comparative test. The results are shown in “Table 2” below.

  The tires used were all tires of tire size 175 / 65R14, Example 1 and Example 4 were the tread pattern tires of FIG. 2, Example 2 and Example 5 were the tread pattern tires of FIG. 4, Example 3 5 and Example 6 are the tread pattern tires of FIG. 5, Example 7 is the tread pattern tires of FIG. 6, and Example 8 is the tread pattern tires of FIG. 7, each having the configuration shown in Table 1 below. doing. Moreover, as tread rubber of each tire of an Example, Examples 1 to 3 and Examples 7 and 8 have rubber hardness, embrittlement temperature, and viscoelasticity Tα as shown in Table 1 below. Using a single rubber material, Examples 4 to 6 are for rubber hardness in summer (region effective in summer performance), tan δ at 35 ° C., and winter (region effective in winter performance). Two kinds of rubber materials having different physical properties having rubber hardness and tan δ were used.

  Comparative Examples 1-3 are the tread pattern tires of FIG. 2 and Comparative Example 4 are the tread pattern tires of FIG. 11, which are the same single rubbers as in Examples 1-3 and Examples 7 and 8, respectively. Material was used.

-DRY Stability The driver's sensory evaluation is performed on the driving stability by running on the DRY road surface, and this is shown as an index, with the larger index value being good.

-WET stability The driver's sensory evaluation is performed on the driving stability by running the vehicle on a wet surface with a water depth of 2 mm, and this is shown as an index. The higher index value is better.

・ Snow performance The driver's sensory evaluation is performed by running the vehicle on a snowy road surface, and this is shown as an index. The higher index value is better.

  In addition, the index value of the said performance is a value on the basis of the comparative example 1 (index | index 100) in any of Examples 1-8 and Comparative Examples 1-4.

  As a result of the above test, by using the mounting structure of the present invention, any of Examples 1 to 8 can ensure excellent winter performance while suppressing a decrease in summer performance as compared with Comparative Examples 1 to 4. Both performances were compatible.

  DESCRIPTION OF SYMBOLS 1 ... Inner liner, 2 ... Tread rubber, 3 ... Side wall, 4 ... Carcass layer, 5 ... Belt layer, 6 ... Bead part, 7 ... Bead core, 10 ... Tire, 11 ... Tread part, 12, 12c ... Circumferential groove , 13, 13a, 13b, 13c ... land portion, 14, 14a, 14c ... transverse groove, 14b ... transverse groove portion, 14c-1 ... some groove portions, 16 ... straight sipe, 17 ... wavy sipe.

Claims (12)

A vehicle tire mounting structure in which the same type of tire is mounted on one of the front and rear driving wheels and the other driven wheel of the vehicle,
A tire having three or more circumferential grooves and land portions defined by the circumferential grooves in the tread portion, where the region on one side in the width direction of the tread is effective for summer performance, the region on the other side Tires having a configuration effective for winter performance are used, the tires on the driving wheel side are mounted with the side having the configuration effective for summer performances outside the vehicle, and the tires on the driven wheel side are the winter season tires. A tire mounting structure for a vehicle, characterized in that the vehicle is mounted with the side having a configuration effective in performance on the outside of the vehicle.   Of the land portions defined by circumferential grooves in the tread portion of the tire tread pattern, the region including at least the outermost first row on the one side in the width direction and the land portion in the next second row is in summer performance. The summer-oriented pattern having an effective configuration, and the region including at least the outermost first row and the next second row of land on the other side is a winter-oriented pattern having a configuration effective for winter performance. Vehicle tire mounting structure.   The sipe is formed in each of the land portion of the summer-oriented pattern and the land portion of the winter-oriented pattern in the tread portion of the tire, and the sipe of the summer-oriented pattern is straight and the sipe of the winter-oriented pattern is wavy. A tire mounting structure for a vehicle as described in 1.   The sipe is formed in each of the land portion of the summer-oriented pattern and the land portion of the winter-oriented pattern in the tread portion of the tire, and the sipe density of the summer-oriented pattern is set smaller than the sipe density of the winter-oriented pattern. 4. A tire mounting structure for a vehicle according to 3.   The void ratio of the summer-oriented pattern in the tread portion of the tire is the same as or larger than the void ratio of the winter-oriented pattern, and the see-through void ratio of the summer-oriented pattern is larger than the see-through void ratio of the winter-oriented pattern. 5. The vehicle tire mounting structure according to any one of 4 above.   A summer-oriented pattern in the tread portion of the tire is a pattern based on a rib structure in which a land portion is continuous in the circumferential direction and is defined by a circumferential groove, and a winter-oriented pattern is defined by a circumferential groove and the land portion is divided by a lateral groove. The tire mounting structure for a vehicle according to any one of claims 2 to 5, wherein the structure is based on a block structure that is intermittent in the circumferential direction.   The tire tread portion has four or more circumferential grooves, and the summer-facing pattern is set in a region including the outermost land portion on one side in the width direction to the land portion in the third row. The vehicle tire mounting structure according to any one of -6.   The tread portion of the tire has four or more circumferential grooves, and the winter pattern is set in a region including the outermost land portion on the other side in the width direction to the third row land portion. The vehicle tire mounting structure according to any one of 2 to 6.   The region of the summer pattern and the region of the winter pattern in the tread portion of the tire are formed of the same rubber material, the rubber hardness at normal temperature is 60 to 80 degrees, the embrittlement temperature is −50 ° C. or less, and the viscoelasticity Tα is It is -50 degreeC--30 degreeC, The tire mounting structure of the vehicle of any one of Claims 1-8.   A region effective in summer performance on one side in the width direction in the tread portion of the tire and a region effective in winter performance on the other side in the width direction are formed of two kinds of rubber materials having different physical properties, The tire mounting of a vehicle according to any one of claims 1 to 8, wherein rubber hardness in a region effective for performance and tan δ at 35 ° C are higher than rubber hardness and tan δ in a region effective for winter performance. Construction.   In the tread, the interface between the rubber material in the region effective in summer performance on one side in the width direction and the rubber material in the region effective in winter performance on the other side in the width direction is in the vicinity of one circumferential groove. And a bottom surface of a lateral groove portion extending laterally from the one circumferential groove is inclined along an interface between the two rubber materials. Item 11. A vehicle tire mounting structure according to Item 10.   At least one side of the tire that is effective for summer performance and the side of the region that is effective for winter performance is marked with an indicator that indicates which side is on the drive wheel side. 12. The vehicle according to claim 1, wherein the side of the region effective for summer performance is mounted on the outside of the vehicle and the side of the driven wheel on the side of the region effective for winter performance is mounted on the vehicle outer side. Tire mounting structure.

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