JP2013071651A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire capable of improving an airflow around the tire.SOLUTION: At least one tire side portion has a large number of protrusions 9 and a large number of recesses 10, the protrusions 9 are formed as protrusive streaks assuming longitudinal shapes in the radial direction of the tire and arranged at intervals in the circumferential direction of the tire, and the recesses 10 are formed in regions among the protrusions 9, respectively. Since an airflow passing through the tire side S is turned into a turbulent flow by the protrusions 9, the air is restrained from spreading by getting away from the tire side S. Thus, the air resistance of the tire is reduced for improvement in fuel economy. Additionally, since the rubber volume of the tire side S is reduced by the recesses 10, the generation of heat can be suppressed. Furthermore, since the recesses 10 make the air turbulent, the air is further restrained from spreading by getting away from the tire side portion S. Thereby, since the heat exhaustibility of the tire side S is improved, the generation of the heat from the tire and a rise in temperature can be suppressed for an increase in the durability of the tire.

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that improves airflow around the tire.

  Conventionally, in Patent Document 1, in order to effectively reduce the air resistance around the tire and improve the fuel efficiency of a vehicle equipped with the tire, a large number of tire circumferential directions and tire radial directions are provided in a predetermined region of the tire outer surface. There is disclosed a pneumatic tire characterized in that a concave portion and a large number of convex portions (projections) are provided in a mixed manner.

  Conventionally, in Patent Document 2, there is a pneumatic tire provided with a large number of concave portions (dimples) and convex portions (pimples) as a stirring portion on the outer surface of the tire (the outer surface of the side portion) in order to prevent a decrease in durability due to heat generation. It is disclosed.

JP 2010-260376 A JP 2010-30547 A

  The pneumatic tires described in Patent Document 1 and Patent Document 2 described above cause turbulent flow (air agitation) around the tire when the vehicle travels by the recess, and the turbulent flow generation effect (stirring effect) is generated by the convex portion. The effect of improving is shown. In other words, the concave portion causes turbulent flow and air agitation, and the convex portion facilitates turbulent flow and air agitation.

  By the way, according to the research by the inventors, it has been found that further effects can be obtained by arranging the convex portions and the concave portions so as to obtain these functions efficiently.

  This invention is made in view of the above, Comprising: It aims at providing the pneumatic tire which can further improve the airflow around a tire.

  In order to solve the above-described problems and achieve the object, the pneumatic tire of the present invention is a pneumatic tire having a large number of convex portions and a large number of concave portions on at least one tire side portion, wherein the convex portions are: It is formed as a long ridge along the tire radial direction and is arranged at intervals in the tire circumferential direction, and the concave portion is provided in a region between the convex portions. To do.

  According to this pneumatic tire, the air flow passes over the convex portion on the surface of the tire side portion. The convex portion makes the air flow turbulent. For this reason, since a turbulent boundary layer is generated in the portion having the convex portion and the passing air is prevented from spreading away from the tire side portion, the air resistance of the tire is reduced, and the fuel efficiency can be improved. Moreover, according to this pneumatic tire, since the recess is provided in the region between the protrusions, the recess reduces the rubber volume of the tire side portion and turbulent air. For this reason, heat generation is suppressed by reducing the rubber volume. Furthermore, the air turbulence by the recesses further suppresses the air passing between the protrusions from spreading away from the tire side part, and the heat dissipation is improved by the air flow, so the tire heat generation and temperature The rise is suppressed, the durability of the tire can be improved, and by suppressing the spread of the air passing between the convex parts to the outside of the tire side part, the air resistance of the tire is further reduced, and the fuel efficiency Can be improved. Thus, according to this pneumatic tire, the airflow around the tire is further improved by the protrusions of the ridges provided on the tire side part and the recesses provided in the region between the protrusions. be able to.

  In the pneumatic tire of the present invention, the region between the convex portions adjacent in the tire circumferential direction is divided into three regions in the tire circumferential direction, and the regions D1 near the convex portions, The region D2 is defined as a region D2 between the regions D1, and the ratios of the concave portions arranged in the regions D1 and the regions D2 are different.

  According to this pneumatic tire, the air flow around the tire can be further improved by changing the ratio of the concave portions arranged in each of the regions D1 and D2. For example, if the arrangement ratio of the recesses in each area D1 is relatively larger than the arrangement ratio of the depressions in the area D2, the heat dissipation in the area where the air tends to stay and collect in the vicinity of the projection tends to be improved. It becomes. On the other hand, for example, if the arrangement ratio of the concave portions in the region D2 is made relatively larger than the arrangement ratio of the concave portions in each region D1, the air passing between the convex portions is separated from the tire side portion in the region D2. Spreading is further suppressed, and the air resistance of the tire tends to be further reduced. Thus, the effect of improving heat dissipation or reducing the air resistance of the tire can be obtained more remarkably by making the ratio of the concave portions arranged in each region D1 and region D2 different.

  The pneumatic tire of the present invention is characterized in that the ratio of the recesses arranged in each region D1 is made equal and the ratio of the recesses arranged in each region D1 is made larger than that of the region D2. And

  According to this pneumatic tire, since the heat dissipation in each region D1 where air tends to stay and accumulate near the convex portion tends to be further improved, the effect of improving the heat dissipation can be obtained more remarkably. Equalizing the ratio of the recesses disposed in each region D1 is an effect of improving heat dissipation in a pneumatic tire in which the tire rotation direction at the time of vehicle mounting is not specified regardless of the tire rotation direction. Is preferable because it can be obtained equally.

  Moreover, the pneumatic tire according to the present invention is characterized in that the interval between the concave portions is reduced as approaching each convex portion.

  According to this pneumatic tire, the closer to the convex portion, the smaller the interval between the concave portions, so that the heat dissipation near the convex portion where air tends to stay and collect tends to be further improved. Effect can be obtained more remarkably.

  Further, the pneumatic tire of the present invention is characterized in that the ratio of the recesses arranged in each of the regions D1 is made equal and the ratio of the recesses arranged in the region D2 is made larger than each of the regions D1. And

  According to this pneumatic tire, the air passing between the convex portions is further suppressed from spreading away from the tire side portion in the region D2, and the air resistance of the tire tends to be further reduced. The effect of reducing the air resistance can be obtained more remarkably. Equalizing the ratio of the recesses disposed in each region D1 is an effect of improving heat dissipation in a pneumatic tire in which the tire rotation direction at the time of vehicle mounting is not specified regardless of the tire rotation direction. Is preferable because it can be obtained equally.

  The pneumatic tire of the present invention is characterized in that the interval between the concave portions is reduced as the distance from the convex portions increases.

  According to this pneumatic tire, the distance between the concave portions decreases as the distance from the convex portion decreases, so that the air flow is further suppressed from spreading away from the tire side portion, and the air resistance of the tire tends to be further reduced. Therefore, the effect of reducing the air resistance of the tire can be obtained more significantly.

  In the pneumatic tire of the present invention, the tire rotation direction at the time of vehicle mounting is specified, and the ratio of the recesses arranged in the region D1 near the projections on the front side in the tire rotation direction is A, the region When the ratio of the recesses disposed in D2 is B and the ratio of the recesses disposed in the region D1 near the protrusions on the rear side in the tire rotation direction is C, the relation of A> B> C is established. It is characterized by.

  According to this pneumatic tire, the air flow during rotation of the tire flows from the front side in the tire rotation direction to the rear side in the tire rotation direction. In this case, in the region D1 closer to the convex portion on the front side in the tire rotation direction, the air flow immediately after overcoming the convex portion tends to stay and accumulate, and the concave portion is aerodynamically depressed because the convex portion is located on the rear side in the tire rotational direction. The effect of is relatively small. Therefore, by increasing the arrangement ratio A of the recesses in the region D1 closer to the convex portion on the front side in the tire rotation direction than the other (B, C), the tire side portion in the region D1 closer to the convex portion on the front side in the tire rotational direction. The air flow is drawn into the surface of the tire and the effect of improving the heat dissipation by the recess or the effect of reducing the air resistance of the tire is likely to be obtained. Further, by reducing the arrangement ratios B and C of the recesses toward the rear side in the tire rotation direction, the air flow becomes easier to separate from the tire side portion as the convex portion on the rear side in the tire rotation direction is approached. Since it becomes easy for the air flow to get over the rear convex portion, the air resistance of the tire can be reduced and the heat can be easily exhausted to improve the heat dissipation.

  The pneumatic tire of the present invention is characterized in that the interval between the concave portions arranged in the region D1 near the convex portion on the front side in the tire rotation direction is made constant in the longitudinal direction of the convex portion.

  When the tire rotation direction when the vehicle is mounted is specified, as described above, the region D1 near the convex portion on the front side of the tire rotational direction is located on the rear side of the convex portion in the tire rotational direction. Immediately after the flow of air stays and collects easily, the effect of the recess is relatively small aerodynamically. Therefore, by making the interval between the concave portions arranged in the region D1 near the convex portion on the front side in the tire rotation direction constant in the longitudinal direction of the convex portion, the length of the convex portion in the region D1 near the convex portion on the front side in the tire rotational direction. The air flow is drawn into the surface of the tire side portion along the direction, and the effect of improving the heat dissipation by the recess or the effect of reducing the air resistance of the tire can be more easily obtained.

  Moreover, the pneumatic tire of the present invention is characterized in that the interval between the concave portions in the region D2 is increased as it approaches the rear side in the tire rotation direction.

  According to this pneumatic tire, the air flow tends to peel from the tire side portion as it approaches the convex portion on the rear side in the tire rotation direction, and the air flow easily gets over the convex portion on the rear side in the tire rotation direction. While reducing the air resistance of a tire, it can be set as the tendency which is easy to obtain the effect of making it easy to exhaust heat and improving heat dissipation.

  The pneumatic tire according to the present invention is characterized in that the concave portion is not disposed in the region D1 near the convex portion on the rear side in the tire rotation direction.

  According to this pneumatic tire, the concave portion is not arranged in the region D1 near the convex portion on the rear side in the tire rotation direction, that is, the arrangement ratio C is set to 0, so that the air approaches the convex portion on the rear side in the tire rotational direction. The air flow is easy to peel off from the tire side part, and the air flow is easy to get over the convex part on the rear side in the tire rotation direction, so that the air resistance of the tire is reduced and the heat dissipation is improved by improving the heat dissipation Can be more easily obtained.

  Further, in the pneumatic tire according to the present invention, the opening ratio A of the recesses arranged in the region D1 near the projections on the front side in the tire rotation direction is such that the recesses in all the regions D1 and the regions D2 are all. 20 [%] or more and 50 [%] or less, and the opening ratio B of the recesses arranged in the region D2 is 5 [%] or more and 30 [30] with respect to all the recesses in each of the regions D1 and the regions D2. %] Or less.

  According to this pneumatic tire, the opening ratio A of the concave portions disposed in the region D1 near the convex portion on the front side in the tire rotation direction is 20% or more and 50 [%] in all the regions D1 and D2 with respect to the concave portions. The following is an effect of drawing air flow into the surface of the tire side portion in the region D1 near the convex portion on the front side of the tire rotation direction to improve the heat dissipation by the concave portion, or reducing the air resistance of the tire. It is preferable when making it easy to obtain. Moreover, it is convex part of the tire rotation direction back side that the opening ratio B of the recessed part arrange | positioned at the area | region D2 is 5 [%] or more and 30 [%] or less with respect to all the recessed parts of each area | region D1 and area | region D2. As the airflow gets closer to the tire, the air flow is easier to peel off from the tire side, and the air flow easily gets over the convex part on the rear side of the tire rotation direction, reducing the air resistance of the tire and making it easier to exhaust heat and heat dissipation It is preferable for obtaining the effect of improving the.

  Moreover, the pneumatic tire of the present invention is characterized in that the concave portion is formed with a larger volume toward the inner side in the tire radial direction.

  Since the rotational speed of the tire side portion becomes relatively slow as it approaches the inner side in the tire radial direction, increasing the volume of the concave portion closer to the portion makes it possible to reduce the rotational speed on the inner side in the tire radial direction. Further, by suppressing the spread of the air passing between the convex portions to the outside of the tire side portion, the tire heat generation and the temperature rise tend to be suppressed, and the air resistance of the tire tends to be further reduced. Further, in a pneumatic tire in which the tire rotation direction at the time of vehicle mounting is specified, the surface of the tire side portion in the region D1 near the convex portion on the front side in the tire rotation direction even if the rotation speed is slow on the inner side in the tire radial direction. It tends to be easy to obtain an effect of improving the heat dissipation by the recess or reducing the air resistance of the tire by drawing the air flow.

  Moreover, the pneumatic tire of the present invention is characterized in that a longitudinal dimension of the convex portion is 5 [mm] or more.

  When the longitudinal dimension of the projection is less than 5 [mm], it is difficult to obtain an effect of turbulent air flow by the projection. For this reason, when the longitudinal dimension of the convex portion is 5 [mm] or more, the effect of causing turbulent air flow and reducing the air resistance of the tire can be significantly obtained.

  In the pneumatic tire of the present invention, the protruding height of the convex portion is 0.5 [mm] or more and 10.0 [mm] or less.

  When the height of the convex portion is less than 0.5 [mm], since the range in which the convex portion contacts the air is small, the air flow is hardly turbulent, and the effect of reducing the tire air resistance is small. In addition, when the height of the convex portion exceeds 10.0 [mm], the range in which the convex portion comes into contact with air is large, so that the air flow behind the convex portion tends to swell, and the air resistance of the tire Reduction effect is reduced. According to this pneumatic tire, since the convex portion appropriately contacts the air, the air flow becomes turbulent, and the swelling of the air behind the convex portion is reduced. Remarkably can be obtained.

  The pneumatic tire according to the present invention is characterized in that the cross-sectional shape of the convex portion has a vertex and gradually spreads toward the bottom surface side.

  According to this pneumatic tire, since the cross-sectional shape orthogonal to the longitudinal direction of the convex portion approximates a triangular shape, the volume of the convex portion is reduced compared to a rectangular cross section, etc. Since the rubber volume is reduced and the increase in tire weight is suppressed, fuel efficiency can be further improved.

  The pneumatic tire of the present invention is characterized in that the cross-sectional shape of the convex portion has at least one arc.

  According to this pneumatic tire, for example, the convex section is formed so that the cross-sectional shape swells in an arc, or the convex section has a cross-sectional shape that is concave in an arc, so that the volume of the convex section is increased. Since it is smaller than a rectangular cross section, the rubber volume of the convex portion is reduced and the increase in tire weight is suppressed, so that fuel efficiency can be further improved.

  In the pneumatic tire according to the present invention, the depth of the recess is 0.5 [mm] or more and 5.0 [mm] or less.

  When the depth of the recess is less than 0.5 [mm], the range in which the inner surface of the recess contacts the air is small, and the air flow is difficult to be turbulent. Further, when the depth of the recess exceeds 5.0 [mm], the range in which the inner surface of the recess contacts the air is too large, and the air resistance tends to increase, and the original rubber volume in the region having the recess Increases the tire weight. According to this pneumatic tire, the air flow is appropriately turbulent when the inner surface of the concave portion comes into contact with air as appropriate, so that the effect of reducing the air resistance of the tire and the effect of improving heat dissipation are remarkable. Can be obtained.

  The pneumatic tire according to the present invention can further improve the air flow around the tire.

FIG. 1 is a meridional sectional view of a pneumatic tire according to an embodiment of the present invention. FIG. 2 is an external view of the pneumatic tire according to the embodiment of the present invention viewed from the tire width direction. FIG. 3 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 4 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 5 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 6 is a partial external view of the pneumatic tire according to the embodiment of the present invention viewed from the tire width direction. FIG. 7 is a cross-sectional view of a part of the tire side portion of the pneumatic tire according to the embodiment of the present invention cut in the tire circumferential direction. FIG. 8 is a partial external view of the pneumatic tire according to the embodiment of the present invention viewed from the tire width direction. FIG. 9 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 10 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 11 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 12 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 13 is a cross-sectional view of a part of the tire side portion of the pneumatic tire according to the embodiment of the present invention cut in the tire circumferential direction. FIG. 14 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 15 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 16 is a partial external view of the pneumatic tire according to the embodiment of the present invention as viewed from the tire width direction. FIG. 17 is a cross-sectional view of a convex portion. FIG. 18 is a cross-sectional view of a convex portion. FIG. 19 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention. FIG. 20 is a chart showing the results of the performance test of the pneumatic tire according to the example of the present invention.

  Embodiments of the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. The constituent elements of this embodiment include those that can be easily replaced by those skilled in the art or those that are substantially the same. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

  FIG. 1 is a meridional sectional view of a pneumatic tire according to the present embodiment. In the following description, the tire radial direction refers to a direction orthogonal to the rotation axis (not shown) of the pneumatic tire 1, and the tire radial direction inner side refers to the side toward the rotation axis in the tire radial direction, the tire radial direction outer side. Means the side away from the rotation axis in the tire radial direction. Further, the tire circumferential direction refers to a direction around the rotation axis as a central axis. Further, the tire width direction means a direction parallel to the rotation axis, the inner side in the tire width direction means the side toward the tire equator plane (tire equator line) CL in the tire width direction, and the outer side in the tire width direction means the tire width direction. Is the side away from the tire equatorial plane CL. The tire equatorial plane CL is a plane that is orthogonal to the rotation axis of the pneumatic tire 1 and passes through the center of the tire width of the pneumatic tire 1. The tire width is the width in the tire width direction between the portions located outside in the tire width direction, that is, the distance between the portions farthest from the tire equatorial plane CL in the tire width direction. The tire equator line is a line along the tire circumferential direction of the pneumatic tire 1 on the tire equator plane CL. In the present embodiment, the same sign “CL” as that of the tire equator plane is attached to the tire equator line.

  As shown in FIG. 1, the pneumatic tire 1 according to the present embodiment includes a tread portion 2, shoulder portions 3 on both sides thereof, and a sidewall portion 4 and a bead portion 5 that are sequentially continuous from the shoulder portions 3. ing. The pneumatic tire 1 includes a carcass layer 6, a belt layer 7, and a belt reinforcing layer 8.

  The tread portion 2 is made of a rubber material (tread rubber), is exposed at the outermost side in the tire radial direction of the pneumatic tire 1, and the surface thereof is the contour of the pneumatic tire 1. A tread surface 21 is formed on the outer peripheral surface of the tread portion 2, that is, on the tread surface that contacts the road surface during traveling. The tread surface 21 is provided with a plurality of (four in this embodiment) main grooves 22 that are straight main grooves extending along the tire circumferential direction and parallel to the tire equator line CL. The tread surface 21 extends along the tire circumferential direction by the plurality of main grooves 22, and a plurality of rib-like land portions 23 parallel to the tire equator line CL are formed. Although not shown in the figure, the tread surface 21 is provided with a lug groove that intersects the main groove 22 in each land portion 23. The land portion 23 is divided into a plurality of portions in the tire circumferential direction by lug grooves. Further, the lug groove is formed to open to the outer side in the tire width direction on the outermost side in the tire width direction of the tread portion 2. Note that the lug groove may have either a form communicating with the main groove 22 or a form not communicating with the main groove 22.

  The shoulder portion 3 is a portion on both outer sides in the tire width direction of the tread portion 2. Further, the sidewall portion 4 is exposed at the outermost side in the tire width direction of the pneumatic tire 1. The bead unit 5 includes a bead core 51 and a bead filler 52. The bead core 51 is formed by winding a bead wire, which is a steel wire, in a ring shape. The bead filler 52 is a rubber material disposed in a space formed by folding the end portion in the tire width direction of the carcass layer 6 at the position of the bead core 51.

  The carcass layer 6 is configured such that each tire width direction end portion is folded back from the tire width direction inner side to the tire width direction outer side by a pair of bead cores 51 and is wound around in a toroidal shape in the tire circumferential direction. It is. The carcass layer 6 is formed by coating a plurality of carcass cords (not shown) arranged in parallel at an angle in the tire circumferential direction with an angle with respect to the tire circumferential direction being along the tire meridian direction. The carcass cord is made of organic fibers (polyester, rayon, nylon, etc.). The carcass layer 6 is provided as at least one layer.

  The belt layer 7 has a multilayer structure in which at least two belts 71 and 72 are laminated, and is disposed on the outer side in the tire radial direction which is the outer periphery of the carcass layer 6 in the tread portion 2 and covers the carcass layer 6 in the tire circumferential direction. It is. The belts 71 and 72 are made by coating a plurality of cords (not shown) arranged in parallel at a predetermined angle (for example, 20 degrees to 30 degrees) with a coat rubber with respect to the tire circumferential direction. The cord is made of steel or organic fiber (polyester, rayon, nylon, etc.). Further, the overlapping belts 71 and 72 are arranged so that the cords intersect each other.

  The belt reinforcing layer 8 is disposed on the outer side in the tire radial direction which is the outer periphery of the belt layer 7 and covers the belt layer 7 in the tire circumferential direction. The belt reinforcing layer 8 is formed by coating a plurality of cords (not shown) arranged substantially parallel (± 5 degrees) in the tire circumferential direction and in the tire width direction with a coat rubber. The cord is made of steel or organic fiber (polyester, rayon, nylon, etc.). The belt reinforcing layer 8 shown in FIG. 1 is disposed so as to cover the end of the belt layer 7 in the tire width direction. The configuration of the belt reinforcing layer 8 is not limited to the above, and is not clearly shown in the figure. However, the belt reinforcing layer 8 is configured to cover the entire belt layer 7 or has two reinforcing layers, for example, on the inner side in the tire radial direction. The reinforcing layer is formed so as to be larger in the tire width direction than the belt layer 7 and is disposed so as to cover the entire belt layer 7, and the reinforcing layer on the outer side in the tire radial direction is disposed so as to cover only the end portion in the tire width direction of the belt layer 7. Alternatively, for example, a configuration in which two reinforcing layers are provided and each reinforcing layer is disposed so as to cover only the end portion in the tire width direction of the belt layer 7 may be employed. That is, the belt reinforcing layer 8 overlaps at least the end portion in the tire width direction of the belt layer 7. The belt reinforcing layer 8 is provided by winding a strip-shaped strip material (for example, a width of 10 [mm]) in the tire circumferential direction.

  FIG. 2 is an external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction. FIGS. 3 to 6 are partial views of the pneumatic tire according to the present embodiment as viewed from the tire width direction. It is an external view. As shown in FIG. 2, the pneumatic tire 1 configured as described above includes at least one tire side portion S provided with a plurality of convex portions 9 that protrude outward from the surface of the tire side portion S. In addition, a large number of recesses 10 that are recessed from the surface of the tire side portion S to the inside of the tire are provided.

  Here, the tire side portion S in FIG. 1 refers to a surface that is uniformly continuous from the ground contact end T of the tread portion 2 to the outer side in the tire width direction and from the rim check line L to the outer side in the tire radial direction. Further, the ground contact T is a tread surface 21 of the tread portion 2 of the pneumatic tire 1 when the pneumatic tire 1 is assembled on a regular rim and filled with a regular internal pressure and 70% of the regular load is applied. In the region where the road contacts the road surface, it means both outermost ends in the tire width direction and continues in the tire circumferential direction. The rim check line L is a line for confirming whether or not the tire rim is assembled normally. Generally, on the front side surface of the bead portion 5, the rim check line L is outside the rim flange in the tire radial direction. However, it is shown as an annular convex line that continues in the tire circumferential direction along the portion that is in the vicinity of the rim flange.

  The regular rim is “standard rim” defined by JATMA, “Design Rim” defined by TRA, or “Measuring Rim” defined by ETRTO. The normal internal pressure is “maximum air pressure” defined by JATMA, the maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “INFLATION PRESSURES” defined by ETRTO. The normal load is “maximum load capacity” defined by JATMA, a maximum value described in “TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES” defined by TRA, or “LOAD CAPACITY” defined by ETRTO.

  As shown in FIG. 2, the convex portion 9 is a rubber material formed in the tire radial direction in the range of the tire side portion S (even if the rubber material constituting the tire side portion S is the rubber material). And may be a rubber material different from the above), and a plurality of protrusions are arranged at intervals in the tire circumferential direction. For example, in the case of a tire for a passenger car, the number of the convex portions 9 in the tire circumferential direction is preferably 10 to 70.

  The convex portion 9 may be formed linearly along the tire radial direction as shown in FIG. 3, and is formed linearly inclined with respect to the tire radial direction as shown in FIG. 4. Alternatively, it may be bent as shown in FIG. 5, or may be bent as shown in FIG. As shown in FIG. 2, the convex portions 9 may be arranged at equal intervals in the tire circumferential direction. Although not clearly shown in the drawing, the convex portions 9 adjacent to each other at predetermined intervals in the tire circumferential direction are defined as 1. The group of the convex parts 9 may be arranged at equal intervals in the tire circumferential direction. Moreover, although the convex part 9 is not shown in a figure, you may arrange | position so that length may become different in the tire circumferential direction alternately.

  Moreover, as for the convex part 9, the outer shape at the time of seeing from a tire width direction is a rectangular shape as shown in FIGS. 2-6, although it does not show clearly in a figure, an edge part is circular arc shape, The end may be pointed or triangular.

  Further, the convex portion 9 has a semicircular shape, a semi-elliptical shape, a semi-elliptical shape, a triangular shape, a quadrangular shape, a trapezoidal shape, or a circular shape at least in a cross-sectional shape perpendicular to the longitudinal direction. Is formed. Here, orthogonal to the longitudinal direction of the convex portion 9 means orthogonal to the extending direction, and when the convex portion 9 is curved, it means orthogonal to the tangent of the curved portion. To do.

  The concave portion 10 is provided in a region between the convex portions 9. As shown in FIGS. 3 to 6, the region having the concave portion 10 is adjacent to the virtual straight line connecting the outermost ends in the tire radial direction of the convex portions 9 adjacent to each other in the tire circumferential direction, in the tire circumferential direction. The region between the imaginary straight lines connecting the innermost ends of the respective convex portions 9 in the tire radial direction is referred to. In addition, although the recessed part 10 should just be arrange | positioned at least in the said area | region, you may be provided in the tire side part S outside the said area | region.

  In the recess 10, the opening shape that opens on the surface of the tire side portion S is formed in a circular shape, an elliptical shape, an oval shape, a polygonal shape, or the like (shown as a circular opening shape in FIG. 2). In addition, the recess 10 is formed in a semicircular shape, a semi-elliptical shape, a semi-elliptical shape, a mortar shape, a rectangular shape, or the like.

  For example, as shown in FIG. 2, the recesses are arranged at equal intervals in the tire circumferential direction and the tire radial direction. Moreover, although not shown in the drawing, the recesses 10 may be arranged in a staggered manner, or may be arranged with reference to a quadrangle or a triangle.

  Thus, the pneumatic tire 1 of the present embodiment has a large number of convex portions 9 and a large number of concave portions 10 in at least one tire side portion S, and the convex portions 9 are elongated along the tire radial direction. The protrusions 10 are formed as ridges and are spaced apart in the tire circumferential direction, and the recesses 10 are provided in regions between the protrusions 9.

  FIG. 7 is a cross-sectional view in which a part of the tire side portion of the pneumatic tire according to the present embodiment is cut in the tire circumferential direction. In FIG. 7, the recess 10 is omitted. For example, when the left side in FIG. 7 is the front side in the tire rotation direction and the right side in FIG. 7 is the rear side in the tire rotation direction, the air flow from the front side in the tire rotation direction as indicated by an arrow F in FIG. Flows backward in the direction of rotation. And this air flow passes over the convex part 9 on the surface of the tire side part S. The convex part 9 makes this air flow turbulent. For this reason, since a turbulent boundary layer is generated in the portion having the convex portion 9 and the passing air is prevented from spreading away from the tire side portion S, the air resistance of the tire is reduced, and the fuel efficiency can be improved. It becomes possible.

  By the way, in the vicinity of the convex portion 9, as shown in FIG. Also, the rubber gauge at the location where the protrusions 9 are provided is thicker than at other locations, so the amount of heat generated by the tire increases, or the temperature of the tire rubber rises due to air with exhaust heat from the engine and brakes. To do. For this reason, there exists a possibility that the heat dissipation on the both sides of the tire circumferential direction of the convex part 9 may fall. In this regard, in the pneumatic tire 1 of the present embodiment, since the recesses 10 are provided in the regions between the protrusions 9, the recesses 10 reduce the rubber volume of the tire side portion S and disturb the air. Let it flow. For this reason, heat generation is suppressed by reducing the rubber volume. Moreover, the air shown by the solid line in FIG. 7 when the recess 10 is provided with respect to the air flow F1 shown by the alternate long and short dash line in FIG. 7 where the recess 10 is not provided due to the turbulent air flow by the recess 10. As in the flow F <b> 2, the air passing between the convex portions 9 is further suppressed from spreading away from the tire side portion S. Thus, by suppressing the spread of the air passing between the convex portions 9 to the outside of the tire side portion S, the heat dissipation is improved by the air flow F2, so that the tire heat generation and the temperature rise are suppressed, The durability of the tire can be improved. Furthermore, the air resistance of the tire is further reduced and the fuel efficiency can be improved by further suppressing the spread of the air passing between the convex portions 9 to the outside of the tire side portion S.

  That is, according to this pneumatic tire 1, the air flow around the tire is respectively generated by the protruding portion 9 of the protrusion provided in the tire side portion S and the recessed portion 10 provided in the region between the protruding portions 9. Further improvements are possible.

  Moreover, as shown in FIGS. 3 to 6, the pneumatic tire 1 according to the present embodiment divides a region between the convex portions 9 adjacent in the tire circumferential direction into three regions in the tire circumferential direction. Each region D1 near each convex portion 9 is defined as a region D2 between each region D1, and the ratio of the concave portions 10 disposed in each region D1 and region D2 is different.

  As shown in FIGS. 3 to 6, the region D <b> 1 has a straight line connecting the midpoints M in the tire radial direction of the adjacent convex portions 9 as a pitch length P, and each region within a range of 1/5 of the pitch length P. This is a region near the convex portion 9. The region D2 is a region between the regions D1 in the range of 3/5 of the pitch length P. As shown in FIGS. 3 to 6, the boundary line between each region D <b> 1 and region D <b> 2 projects the center line G of the convex portion 9 passing through the center of the convex portion 9 along the longitudinal direction of the convex portion 9. It is assumed that the portion 9 is disposed at a position that is 1/5 of the pitch length P from the convex portion 9 based on the arrangement of the portion 9 in the tire circumferential direction.

  According to this pneumatic tire 1, it is possible to further improve the air flow around the tire by making the ratios of the recesses 10 arranged in the respective regions D1 and D2 different. For example, if the arrangement ratio of the recesses 10 in each area D1 is relatively larger than the arrangement ratio of the recesses 10 in the area D2, the area D1 in FIG. This tends to improve the heat dissipation. On the other hand, for example, if the arrangement ratio of the recesses 10 in the region D2 is relatively larger than the arrangement ratio of the recesses 10 in each region D1, the air passing between the protrusions 9 is tire side portions in the region D2. Spreading away from S is further suppressed, and the air resistance of the tire tends to be further reduced. Thus, by making the ratios of the recesses 10 arranged in the respective regions D1 and D2 different, it is possible to obtain the effect of improving the heat dissipation or the effect of reducing the air resistance of the tire more remarkably. Become.

  Note that the arrangement ratio of the recesses 10 means that the opening area and depth of the recesses 10 are constant (the volume of the recesses 10 is constant) and the intervals between the recesses 10 are different even if the intervals between the recesses 10 are different. The area or depth may be varied (the volume of the recess 10). In manufacturing a tire, it is easier and preferable to make the interval between the recesses 10 different by making the opening area and depth of the recesses 10 constant (the volume of the recesses 10 is constant).

  Specifically, the pneumatic tire 1 of the present embodiment is disposed in each region D1, as shown in FIG. 8 which is a partial external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction. The ratio of the concave portions 10 is made equal, and the ratio of the concave portions 10 arranged in each region D1 is made larger than that of the region D2. FIG. 8 illustrates a form in which the convex portion 9 is formed linearly along the tire radial direction and the concave portion 10 is opened in a circular shape.

  According to this pneumatic tire 1, since the heat dissipation in each region D1 where air is likely to stay and collect in the vicinity of the convex portion 9 tends to be improved, the effect of improving the heat dissipation can be obtained more remarkably. It becomes possible. Making the proportion of the recesses 10 arranged in each region D1 equal improves the heat dissipation in a pneumatic tire in which the tire rotation direction at the time of vehicle mounting is not specified regardless of the tire rotation direction. It is preferable in that the same effect can be obtained.

  Furthermore, as shown in FIG. 9 which is a partial external view of the pneumatic tire according to the present embodiment viewed from the tire width direction, the pneumatic tire 1 according to the present embodiment has a concave portion as it approaches each convex portion 9. It is preferable to reduce the arrangement interval of 10. In this case, the opening area and the depth of the recess 10 are constant (the volume of the recess 10 is constant), and the intervals in the tire circumferential direction of the recess 10 are varied. FIG. 9 illustrates an example in which the convex portion 9 is linearly formed along the tire radial direction and the concave portion 10 is opened in a circular shape.

  According to this pneumatic tire 1, the closer to the convex portion 9, the smaller the arrangement interval of the concave portions 10, so that the heat dissipation near the convex portion 9 where air tends to stay and collect tends to be further improved. The effect of improving heat dissipation can be obtained more remarkably.

  Moreover, the pneumatic tire 1 of the present embodiment is a recess disposed in each region D1, as shown in FIG. 10 which is a partial external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction. The ratio of 10 is made equal, and the ratio of the recesses 10 arranged in the region D2 is made larger than each region D1. FIG. 10 illustrates a form in which the convex portion 9 is formed linearly along the tire radial direction and the concave portion 10 is opened in a circular shape.

  According to the pneumatic tire 1, air passing between the convex portions 9 is further suppressed from spreading away from the tire side portion S in the region D <b> 2, and the air resistance of the tire tends to be further reduced. The effect of reducing the air resistance of the tire can be obtained more remarkably. Making the proportion of the recesses 10 arranged in each region D1 equal improves the heat dissipation in a pneumatic tire in which the tire rotation direction at the time of vehicle mounting is not specified regardless of the tire rotation direction. It is preferable in that the same effect can be obtained.

  Furthermore, the pneumatic tire 1 of the present embodiment has a concave portion as it moves away from each convex portion 9 as shown in FIG. 11 which is a partial external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction. It is preferable to reduce the arrangement interval of 10. In this case, the opening area and the depth of the recess 10 are constant (the volume of the recess 10 is constant), and the intervals in the tire circumferential direction of the recess 10 are varied. In addition, FIG. 11 has illustrated the form in which the convex part 9 was formed linearly along the tire radial direction, and the recessed part 10 was opened circularly.

  According to the pneumatic tire 1, the distance between the concave portions 10 decreases as the distance from the convex portion 9 decreases, so that the air flow is further suppressed from spreading away from the tire side portion S, and the air resistance of the tire is further increased. Since it tends to be reduced, the effect of reducing the air resistance of the tire can be obtained more remarkably.

  The pneumatic tire 1 of the present embodiment is a tire rotation direction when the vehicle is mounted, as shown in FIG. 12 which is a partial external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction. Is specified, and the ratio of the recesses 10 disposed in the region D1 near the convex portion 9 on the front side in the tire rotation direction is A, the ratio of the concave portions 10 disposed in the region D2 is B, and the convex portion on the rear side in the tire rotation direction When the ratio of the recesses 10 arranged in the region D1 closer to 9 is C, the relation of A> B> C is established. FIG. 12 illustrates a form in which the convex portion 9 is formed linearly along the tire radial direction and the concave portion 10 is opened in a circular shape.

  Here, the pneumatic tire 1 in which the tire rotation direction at the time of mounting on the vehicle is specified is not clearly shown in the drawing, but the tire rotation direction is indicated by, for example, an index provided on the sidewall portion 4. That is, the tire rotation direction is defined by assembling the rim according to the designation of the tire rotation direction and mounting the rim on the vehicle.

  FIG. 13 is a cross-sectional view in which a part of the tire side portion of the pneumatic tire according to the present embodiment is cut in the tire circumferential direction. In FIG. 13, the recess 10 is omitted. As shown in FIG. 13, the air flow during the rotation of the tire flows from the front side in the tire rotation direction to the rear side in the tire rotation direction, as indicated by an arrow F in FIG. 13. In this case, since the region D1 near the convex portion 9 on the front side in the tire rotation direction is located on the rear side in the tire rotational direction of the convex portion 9, the air flow immediately after overcoming the convex portion 9 tends to stay and accumulate, In particular, the effect of the recess 10 is relatively small. Therefore, by increasing the arrangement ratio A of the concave portions 10 in the region D1 near the convex portion 9 on the front side in the tire rotation direction as compared with the other (B, C), an air flow F3 indicated by a solid line in FIG. The air flow is drawn into the surface of the tire side portion S in the region D1 near the convex portion 9 on the front side in the tire rotation direction, and the effect of improving the heat dissipation by the concave portion 10 or the effect of reducing the air resistance of the tire is easily obtained. Let it be a trend. Further, by decreasing the arrangement ratios B and C of the recesses 10 toward the rear side in the tire rotation direction, as the air flow F3 indicated by the solid line in FIG. The air flow is easy to peel off from the tire side portion S, and the air flow easily gets over the convex portion 9 on the rear side in the tire rotation direction. Therefore, the air resistance of the tire is reduced, and heat is easily exhausted to reduce heat dissipation. It becomes possible to improve.

  Further, as shown in FIG. 12, the pneumatic tire 1 of the present embodiment is a region D1 near the convex portion 9 on the front side in the tire rotation direction in the pneumatic tire 1 in which the tire rotation direction when the vehicle is mounted is specified. It is preferable to make the interval between the concave portions 10 arranged in the vertical direction constant in the longitudinal direction of the convex portions 9.

  As described above, in the region D1 near the convex portion 9 on the front side in the tire rotation direction, the air flow immediately after overcoming the convex portion 9 is likely to stay and accumulate because the convex portion 9 is located on the rear side in the tire rotational direction. The effect of the recess 10 is aerodynamically relatively small. Therefore, in the region D1 near the convex portion 9 on the front side in the tire rotation direction by making the interval between the concave portions 10 arranged in the region D1 near the convex portion 9 on the front side in the tire rotation direction constant in the longitudinal direction of the convex portion 9, The air flow is drawn into the surface of the tire side part S along the longitudinal direction of the convex part 9, and the effect of improving the heat dissipation by the concave part 10 or the effect of reducing the air resistance of the tire is more likely to be obtained.

  Furthermore, as shown in FIG. 14 which is a partial external view of the pneumatic tire 1 according to the present embodiment as viewed from the tire width direction, the pneumatic tire 1 according to the present embodiment is the tire rotation direction when the vehicle is mounted. In the pneumatic tire 1 in which is designated, it is preferable to increase the arrangement interval of the recesses 10 in the region D2 as it approaches the rear side in the tire rotation direction. FIG. 14 illustrates a form in which the convex portion 9 is formed linearly along the tire radial direction and the concave portion 10 is opened in a circular shape.

  The space | interval of the recessed part 10 means the space | interval of the recessed part 10 in a tire radial direction or a tire circumferential direction. According to this pneumatic tire 1, as the distance between the concave portions 10 in the region D <b> 2 increases as the distance toward the rear side in the tire rotation direction increases, the air flow increases toward the tire side as the distance from the convex portion 9 on the rear side in the tire rotation direction approaches. Since it is easy to peel off from the part S and the air flow easily gets over the convex part 9 on the rear side in the tire rotation direction, the air resistance of the tire is reduced and the effect of improving heat dissipation by making it easier to exhaust heat is obtained. It tends to be easy.

  Furthermore, the pneumatic tire 1 of the present embodiment is a tire rotation direction when the vehicle is mounted, as shown in FIG. 15 which is a partial external view of the pneumatic tire according to the present embodiment viewed from the tire width direction. In the pneumatic tire 1 in which is designated, the concave portion 10 may not be disposed in the region D1 near the convex portion 9 on the rear side in the tire rotation direction. FIG. 15 illustrates a form in which the convex portion 9 is formed linearly along the tire radial direction and the concave portion 10 is opened in a circular shape.

  According to this pneumatic tire 1, the concave portion 10 is not arranged in the region D1 near the convex portion 9 on the rear side in the tire rotation direction, that is, the arrangement ratio C is set to 0, so that the convex portion 9 on the rear side in the tire rotational direction. As the air flow approaches, the air flow easily separates from the tire side portion S and the air flow easily gets over the convex portion 9 on the rear side in the tire rotation direction, so that the air resistance of the tire is reduced and heat is easily exhausted. The effect of improving heat dissipation is more likely to be obtained.

  Furthermore, in the pneumatic tire 1 according to the present embodiment, in the pneumatic tire 1 in which the tire rotation direction at the time of vehicle mounting is specified, the concave portion 10 disposed in the region D1 near the convex portion 9 on the front side in the tire rotation direction. The opening ratio A is 20% to 50% with respect to all the recesses 10 in each of the regions D1 and D2, and the opening ratio B of the recesses 10 arranged in the region D2 is set in each region D1 and region. It is preferable that it is 5 [%] or more and 30 [%] or less with respect to all the recessed parts 10 of D2.

  The opening ratio A of the concave portion 10 disposed in the region D1 near the convex portion 9 on the front side in the tire rotation direction is 20% to 50% with respect to all the concave portions 10 in each of the regions D1 and D2. However, in the region D1 near the convex portion 9 on the front side in the tire rotation direction, an effect of improving the heat dissipation by the concave portion 10 by drawing the air flow into the surface of the tire side portion S or reducing the air resistance of the tire. It is preferable to make it easy to obtain. In addition, the opening ratio B of the recesses 10 disposed in the region D2 is 5% to 30% with respect to all the recesses 10 in each of the regions D1 and D2. The air flow is easily separated from the tire side portion S as the convex portion 9 is approached, and the air flow easily gets over the convex portion 9 on the rear side in the tire rotation direction, thereby reducing the air resistance of the tire and exhausting heat. It is preferable in order to obtain the effect of improving the heat dissipation by facilitating.

  Moreover, in the pneumatic tire 1 of the present embodiment, as shown in FIG. 16 which is a partial external view of the pneumatic tire according to the present embodiment as viewed from the tire width direction, the recess 10 is formed on the inner side in the tire radial direction. It is preferable that the volume is increased toward the surface. FIG. 16 illustrates a form in which the convex portion 9 is linearly formed along the tire radial direction and the concave portion 10 is opened in a circular shape.

  The volume of the recess 10 varies depending on the depth of the recess 10 or the area of the opening of the recess 10. For example, FIG. 16 illustrates a mode in which the depth of the recess 10 is constant and the area of the opening is gradually increased toward the inside in the tire radial direction. Since the rotation speed of the tire side portion S is relatively slow as it approaches the inner side in the tire radial direction, the rotation speed is slower on the inner side in the tire radial direction by increasing the volume of the concave portion closer to the portion. However, by further suppressing the spread of the air passing between the convex portions 9 to the outside of the tire side portion S, the tire heat generation and the temperature rise tend to be suppressed, and the tire air resistance is further reduced. Become. Further, in the pneumatic tire 1 in which the tire rotation direction at the time of vehicle mounting is specified, even if the rotation speed is slow inside the tire radial direction, the tire side portion It tends to be easy to obtain an effect of improving the heat dissipation by the recess 10 by reducing the air flow to the surface of S or reducing the air resistance of the tire. Although FIG. 16 shows the pneumatic tire 1 in which the tire rotation direction when the vehicle is mounted is designated, the pneumatic tire 1 may not be designated when the vehicle is mounted. It is possible to obtain the above effect of increasing the volume of the concave portion 10 toward the radially inner side.

  In the pneumatic tire 1 of the present embodiment, it is preferable that the longitudinal dimension of the convex portion 9 is 5 [mm] or more.

  When the longitudinal dimension of the convex portion 9 is less than 5 [mm], it is difficult to obtain an effect of turbulent air flow by the convex portion 9. For this reason, when the longitudinal dimension of the convex portion 9 is set to 5 [mm] or more, it becomes possible to remarkably obtain the effect of turbulent air flow and reducing the air resistance of the tire.

  In the pneumatic tire 1 of the present embodiment, it is preferable that the protruding height of the convex portion 9 is 0.5 [mm] or more and 10.0 [mm] or less.

  When the height of the convex portion 9 is less than 0.5 [mm], since the range in which the convex portion 9 contacts the air is small, the air flow is hardly turbulent and the effect of reducing the tire air resistance is small. . Moreover, when the height of the convex part 9 exceeds 10.0 [mm], since the range in which the convex part 9 contacts air is large, the air flow behind the convex part 9 tends to swell, and the tire The effect of reducing air resistance is reduced. In this regard, according to the pneumatic tire 1 of the present embodiment, the convex portion 9 appropriately contacts the air, whereby the air flow is turbulent, and the swelling of the air behind the convex portion 9 is reduced. The effect of reducing the air resistance of the tire can be significantly obtained. In addition, in order to obtain the effect which reduces the air resistance of a tire more notably, it is preferable that the height of the convex part 9 shall be 1 [mm] or more and 5 [mm] or less. In addition, the range whose height of the convex part 9 is 0.5 [mm] or more and 10.0 [mm] or less is preferable in a pneumatic tire for passenger cars, and in the case of a pneumatic tire having a large outer diameter for heavy loads. Is not limited to this range and exceeds the range for passenger cars.

  Moreover, in the pneumatic tire 1 of the present embodiment, it is preferable that the cross-sectional shape of the convex portion 9 has a vertex and gradually spreads toward the bottom surface side.

  That is, the cross-sectional shape orthogonal to the longitudinal direction of the convex portion 9 approximates a triangular shape, and thus the volume of the convex portion 9 is reduced compared to a rectangular cross section, etc. The fuel consumption can be further improved because the tire weight is reduced and the increase in tire weight is suppressed.

  In the pneumatic tire 1 of the present embodiment, it is preferable that the cross-sectional shape of the convex portion 9 has at least one arc.

  For example, as shown in FIG. 17 which is a cross-sectional view of the convex portion, the cross-sectional shape of the convex portion 9 is formed so as to swell with an arc, or as shown in FIG. 18 which is a cross-sectional view of the convex portion, Since the cross-sectional shape of the convex portion 9 is formed so as to be recessed with an arc, the volume of the convex portion 9 is smaller than that of a rectangular cross section, etc., so the rubber volume of the convex portion 9 is reduced and the tire weight is increased. Therefore, fuel consumption can be further improved.

  In the pneumatic tire 1 of the present embodiment, the depth of the recess 10 is preferably 0.5 [mm] or more and 5.0 [mm] or less.

  When the depth of the concave portion 10 is less than 0.5 [mm], the range in which the inner surface of the concave portion 10 is in contact with air is small, so that the air flow is less likely to be turbulent. Further, when the depth of the recess 10 exceeds 5.0 [mm], the range in which the inner surface of the recess 10 contacts the air is too large, and the air resistance tends to increase, and the region having the recess 10 originally exists. Since the rubber volume of the tire increases, the tire weight increases. In this regard, according to the pneumatic tire 1 of the present embodiment, the air flow is appropriately turbulent by appropriately contacting the inner surface of the recess 10 with the air, the effect of reducing the air resistance of the tire, The effect of improving the heat dissipation can be remarkably obtained. In addition, the range where the depth of the recessed part 10 is 0.5 [mm] or more and 5.0 [mm] or less is preferable in the pneumatic tire for passenger cars, and in the case of a pneumatic tire having a large outer diameter for heavy loads. Not limited to this range, it exceeds the range for the passenger car.

  In addition, the pneumatic tire 1 mentioned above is applied not only for passenger cars but also for heavy loads and run-flat pneumatic tires. In the case of a passenger car, the effect is obtained as described above. Further, in the case of heavy loads, particularly at a heavy load, the convex portion 9 suppresses the deformation of the tire when the tire side portion S is compressed, and the concave portion 10 increases the temperature when the tire side portion S is compressed. Suppress and improve durability. Also in the case of run-flat, particularly during puncture, the convex portion 9 further suppresses the deformation of the tire when the tire side portion S is compressed, and the concave portion 10 increases the temperature when the tire side portion S is compressed. To improve durability.

  In this example, performance tests on fuel efficiency and load durability were performed for a plurality of types of pneumatic tires with different conditions (see FIGS. 19 and 20).

  In this performance test, a pneumatic tire having a tire size of 185 / 65R15 was assembled on a regular rim and filled with a regular internal pressure.

  In the fuel efficiency performance test, the pneumatic tire is mounted on a small front wheel drive vehicle with a displacement of 1500 [cc] + motor assist, and this test vehicle uses a test course with a circumference of 2 [km] at a speed of 100 [hours]. km / h] was measured for 50 laps. Then, based on the measurement result, the fuel efficiency improvement rate is index-evaluated using the conventional pneumatic tire as a reference (100). This index evaluation shows that the fuel efficiency improvement rate is improved as the value increases.

  In the load durability performance test, the pneumatic tire was mounted on a regular rim, and the air pressure was set to 180 [kPa]. The speed of the pneumatic tire was 81 [km / h] in an environment controlled to an ambient temperature of 38 ± 3 [° C.] using a drum tester having a steel surface with a smooth drum surface and a diameter of 1707 [mm]. The total distance traveled until the tire breaks by increasing the load by 13 [%] every 2 hours from 88 [%] of the maximum load specified by JATMA was measured. Based on the measurement results, the load durability is index-evaluated using the conventional pneumatic tire as a reference (100). This index evaluation shows that the load durability is improved as the numerical value increases.

  In FIG. 19, the conventional pneumatic tire does not have convex portions and concave portions at the tire side portions on both sides. Moreover, the pneumatic tire of the comparative example is provided with protrusions on the ridges on the tire side portions on both sides, but does not have a recess between the protrusions. In addition, the convex part has a uniform length along the tire radial direction, is arranged at equal intervals in the tire circumferential direction, is provided in the tire circumferential direction, has a width of 3 [mm], and has a pitch length P of 51 [mm].

  On the other hand, in FIGS. 19 and 20, the pneumatic tires of Examples 1 to 18 are provided with convex portions on the tire side portions on both sides, and are provided with concave portions between the convex portions. In addition, the convex part has a uniform length along the tire radial direction, is arranged at equal intervals in the tire circumferential direction, is provided in the tire circumferential direction, has a width of 3 [mm], and has a pitch length P of 51 [mm]. In addition, the opening area and depth of the recesses are constant (the volume is constant) in Examples 1 to 12 and 14, and the openings are constant in Examples 13 and 15 to 18. The area (volume) is different. And as for the pneumatic tire of Example 1- Example 3, the opening ratio (arrangement ratio) of a recessed part is each area | region D1 = area | region D2, Comprising: The space | interval of a recessed part is made equal. Further, in the pneumatic tires of Examples 4 to 6, the opening ratio (arrangement ratio) of the recesses is region D1 = region D1, and region D1> region D2. Among them, in Example 6, the interval between the concave portions is arranged to be smaller as the convex portion is approached. In the pneumatic tires of Example 7 and Example 8, the opening ratio (arrangement ratio) of the recesses is region D1 = region D1, and region D1 <region D2. Among them, in Example 8, the interval between the concave portions is arranged to become smaller as the distance from the convex portion increases. In the pneumatic tires of Examples 9 to 18, the rotation direction of the tire is specified, and the opening ratios (arrangement ratios) A, B, and C of the recesses have a relationship of A> B> C. Among them, in the pneumatic tires of Example 11, Example 12, and Example 18, the distance in the tire radial direction between the recesses in the region D1 on the front side in the tire rotation direction is constant. In the pneumatic tires of Example 12 and Example 18, the arrangement interval of the recesses in the region D2 on the rear side in the tire rotation direction is increased. In the pneumatic tires of Examples 14 to 18, no recess is provided in the apex region D1 on the rear side in the tire rotation direction. In the pneumatic tire of Example 16, the cross-sectional shape of the convex portion is a triangle (isosceles triangle). In the pneumatic tires of Examples 17 and 18, the cross-sectional shape of the convex portion is formed by a recess having a circular arc on two sides (see FIG. 18).

  And as shown to the test result of FIG. 19 and FIG. 20, it turns out that the pneumatic tire of Example 1- Example 18 has improved fuel consumption and load durability.

DESCRIPTION OF SYMBOLS 1 Pneumatic tire 9 Convex part 10 Concave part S Tire side part T Grounding end L Rim check line D1 Area | region near convex part D2 Area | region between each area | region D1

Claims (17)

In a pneumatic tire having a large number of convex portions and a large number of concave portions on at least one tire side portion,
The convex portions are formed as elongated protrusions along the tire radial direction, and are arranged at intervals in the tire circumferential direction,
The pneumatic tire according to claim 1, wherein the concave portion is provided in a region between the convex portions.   The region between the convex portions adjacent in the tire circumferential direction is divided into three regions in the tire circumferential direction to form the regions D1 near the convex portions and the regions D2 between the regions D1, 2. The pneumatic tire according to claim 1, wherein the ratio of the concave portions arranged in each of the regions D <b> 1 and the region D <b> 2 is made different.   The ratio of the said recessed part arrange | positioned at each said area | region D1 is made equal, and the ratio of the said recessed part arrange | positioned at each said area | region D1 is made larger than the said area | region D2, The pneumatic of Claim 2 characterized by the above-mentioned. tire.   The pneumatic tire according to claim 3, wherein an interval between the concave portions is reduced as approaching each convex portion.   The ratio of the said recessed part arrange | positioned at each said area | region D1 is made equal, and the ratio of the said recessed part arrange | positioned at the said area | region D2 is made larger than each said area | region D1, The pneumatic of Claim 2 characterized by the above-mentioned. tire.   The pneumatic tire according to claim 5, wherein an interval between the concave portions is reduced as the distance from each convex portion increases.   The tire rotation direction at the time of mounting on the vehicle is specified, and the ratio of the recesses arranged in the region D1 near the projections on the front side of the tire rotation direction is A, and the ratio of the recesses arranged in the region D2 is The relationship of A> B> C is established, where C is the ratio of the concave portions arranged in the region D1 near the convex portion on the rear side in the tire rotation direction. Pneumatic tire.   The pneumatic tire according to claim 7, wherein the interval between the concave portions arranged in the region D <b> 1 near the convex portion on the front side in the tire rotation direction is made constant in the longitudinal direction of the convex portion.   9. The pneumatic tire according to claim 7, wherein an interval between the concave portions in the region D <b> 2 is increased as approaching the rear side in the tire rotation direction.   The pneumatic tire according to any one of claims 7 to 9, wherein the concave portion is not disposed in the region D1 near the convex portion on the rear side in the tire rotation direction.   The opening ratio A of the concave portions arranged in the region D1 near the convex portion on the front side in the tire rotation direction is 20% to 50% with respect to the concave portions in each of the regions D1 and the regions D2. The opening ratio B of the recesses disposed in the region D2 is 5% to 30% with respect to the recesses in all the regions D1 and the region D2. The pneumatic tire according to any one of claims 7 to 10.   The pneumatic tire according to any one of claims 1 to 11, wherein the concave portion is formed to increase in volume toward the inner side in the tire radial direction.   The pneumatic tire according to any one of claims 1 to 12, wherein a longitudinal dimension of the convex portion is 5 mm or more.   The pneumatic tire according to any one of claims 1 to 13, wherein a protruding height of the convex portion is not less than 0.5 [mm] and not more than 10.0 [mm].   The pneumatic tire according to any one of claims 1 to 14, wherein a cross-sectional shape of the convex portion has a vertex and gradually spreads toward a bottom surface side.   The pneumatic tire according to any one of claims 1 to 15, wherein a cross-sectional shape of the convex portion has at least one arc.   The depth of the said recessed part is 0.5 [mm] or more and 5.0 [mm] or less, The pneumatic tire as described in any one of Claims 1-16 characterized by the above-mentioned.

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