Pneumatic tire and mold for molding pneumatic tire

Abstract

To provide a pneumatic tire having high designability by imparting a sense of brilliance based on strong contrast to the tire side surface. [Solution] A tire 1, which is one example of an embodiment, includes a plurality of protrusions 31 formed on a tire side surface 13, which is an axially outer side surface of the tire, on the tire radially inward side of the ground contact edge of the tread and on the tire radially outward side of the rim line. Each protrusion 31 has a polygonal shape having a first surface 33 erected from the tire side surface 13 at an angle in the range of ±15% based on a surface standing upright at 90 degrees to the tire side surface 13, and a second surface 34 connected to the first surface 33 at its apex and rising so as to be inclined at an angle greater than 90 degrees + 15% with respect to the tire side surface 13.

Description

[Technical field]

[0001] The present invention relates to a pneumatic tire and a mold for molding a pneumatic tire, and more particularly to a pneumatic tire having a plurality of protrusions formed on a tire side surface, which is an axially outer surface of the tire radially outward from the rim line. [Background technology]

[0002] In recent years, in order to improve the design of tires, it has been considered to provide a plurality of protrusions on the tire side surface. For example, Patent Document 1 describes that a plurality of protrusions protruding outward from the tire are regularly arranged on the surface of the tire side portion, the maximum width and maximum height of the protrusions are within a predetermined range, and the arrangement interval of the protrusions along the tire surface is greater than 0.1 μm and less than 100 μm. Patent Document 1 describes that this makes it possible to form an optimal air relaxation layer on the tire surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-169827 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, simply arranging a plurality of protrusions regularly on the tire side surface leaves room for improvement in terms of design. Specifically, in order to improve the design of the tire side surface, it is possible to give the tire side surface a sense of shine based on strong contrast. However, the configuration described in Patent Document 1 does not take into consideration the creation of such a sense of shine, and there is room for improvement in terms of realizing a tire with high design.

[0005] An object of the present invention is to provide a pneumatic tire and a molding die thereof that have a high design quality by imparting a sense of shine based on strong contrast to the tire side surface. [Means for solving the problem]

[0006] The pneumatic tire of the present invention has a plurality of protrusions formed on the tire side surface, which is the axially outer side surface of the tire, radially inward from the ground contact edge of the tread and radially outward from the rim line, and each of the plurality of protrusions has a polygonal shape having at least one first surface erected from the tire side surface at an angle in the range of ±15% based on a surface standing upright at 90 degrees to the tire side surface, and at least one second surface connected at an apex to the first surface and erected so as to be inclined at an angle greater than 90 degrees + 15% with respect to the tire side surface.

[0007] The pneumatic tire molding die according to the present invention is a pneumatic tire molding die for molding the pneumatic tire according to the present invention, and has a plurality of recesses on the molding surface corresponding to the plurality of protrusions. Effect of the Invention

[0008] With the pneumatic tire and mold for molding a pneumatic tire according to the present invention, a light reflective surface can be formed on the tire side surface by the second surface, and a shadow area such as a black line can be generated by the first surface, thereby providing a strong contrast to the tire side surface. This makes it possible to create an excellent sense of brilliance on the tire side surface by utilizing the reflection of light, thereby realizing a tire with excellent design. [Brief description of the drawings]

[0009] [Figure 1] FIG. 2 is a diagram showing a tire contour shape in a meridian section of a pneumatic tire that is one example of an embodiment, the diagram showing the ranges in which a plurality of protrusions are formed. [Figure 2A] 1 is a diagram showing an annular portion including two pattern forming portions applied to a tire side surface of a pneumatic tire according to an embodiment. FIG. [Figure 2B] FIG. 2B is an enlarged view of the upper portion of FIG. 2A. [Diagram 3] 2C is an enlarged view of a portion in the circumferential direction of the tire side surface including part A in FIG. 2B, in which the contrast between the reflective surface and the shadow portion is emphasized. [Figure 4] FIG. 4 is an enlarged perspective view corresponding to a portion B in FIG. [Diagram 5] 5 is a view of part C in FIG. 4 as viewed from the outside in a direction perpendicular to the protrusion formation reference surface. [Figure 6] 5 is a perspective view of the pattern-forming portion shown in FIG. 4, seen from a position away in the tire circumferential direction, approaching the tire side surface. FIG. [Figure 7] 6 is an enlarged perspective view of a part of the pattern region shown in FIG. 5 as viewed from the radial outside of the tire. [Figure 8] FIG. 5 is a cross-sectional view taken along the line DD in FIG. [Figure 9] FIG. 9 is an enlarged view of part E in FIG. 8. [Figure 10] FIG. 2 is a diagram illustrating the shape of a portion of a pattern area on a tire side surface as viewed from the outside in a direction perpendicular to a protrusion formation reference surface in an embodiment. [Figure 11] 10 is a schematic diagram showing that, in an embodiment, after an air flow collides with a protrusion, turbulence causes the air flow to reattach to another protrusion downstream, and the separation point is likely to be located downstream. FIG. [Figure 12] 13 is a schematic diagram showing that in the configuration of another example of an embodiment in which the projection pitch ratio is less than 2, the surface of the projections does not generate turbulence, just like a smooth surface. FIG. [Figure 13] FIG. 11 is a schematic diagram showing, by simulating with a cylinder Sa, the generation of a wake region due to a separated air flow on the downstream side of the air flow from a tire side surface in a configuration of another example in which the protrusion pitch ratio is less than 2. [Figure 14] FIG. 13 is a schematic diagram illustrating, by using a cylinder S, how the width of the wake region caused by the separated air flow becomes narrower downstream of the air flow from the tire side surface, thereby increasing the effect of reducing negative pressure in an embodiment. [Figure 15]FIG. 2 is a cross-sectional view showing a mold for molding a pneumatic tire in an embodiment. [Figure 16] FIG. 2 is a perspective view showing a part of a portion of a pneumatic tire molding die in which recesses corresponding to a plurality of protrusions are formed in an embodiment. [Figure 17] FIG. 11 is a cross-sectional view showing a plurality of protrusions formed so as to protrude from different surfaces of a tire side surface in a pneumatic tire according to another example of an embodiment. [Figure 18] FIG. 3 is a view corresponding to FIG. 2B in a pneumatic tire according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an example of an embodiment of a pneumatic tire and a molding die thereof according to the present invention will be described in detail with reference to the drawings. The embodiment described below is merely an example, and the present invention is not limited to the following embodiment. In addition, the present invention includes selective combinations of the respective components of the multiple embodiments and modified examples described below.

[0011] FIG. 1 is a diagram showing a tire contour shape in a meridian cross section of a pneumatic tire 1 as an example of an embodiment, and is a diagram showing the range of formation of a plurality of protrusions. As shown in FIG. 1, the pneumatic tire 1 has a tread 10 which is a portion that comes into contact with a road surface. Hereinafter, the "pneumatic tire 1" will be referred to as the "tire 1". The tread 10 has a tread pattern including a plurality of blocks, and is formed in an annular shape along the tire circumferential direction. In the illustrated example, the tread 10 is shown as being formed of a single block, but in reality, the tread 10 includes a plurality of blocks separated in the tire axial direction X. The plurality of blocks are separated by a circumferential groove extending in the tire circumferential direction. The tread 10 has a ground contact end T. In FIG. 1, the tire axial direction is indicated by X, and the tire radial direction is indicated by Y.

[0012] Hereinafter, the configuration of the tire 1 will be described mainly on the vehicle outer side (OUT side) with respect to the center CL in the tire axial direction X. The tire 1 is symmetrical between the vehicle outer side and the vehicle inner side with respect to the shape other than a pattern area including a recessed portion where a protrusion is provided on the tire side surface described later.

[0013] The tire 1 includes a sidewall 12 that is provided at an end on the outer side of the tread 10 in the tire axial direction X and bulges outward most in the tire axial direction X, and a bead (not shown) that is fixed to a wheel rim. The sidewall 12 and the bead are formed in an annular shape along the tire circumferential direction. The sidewall 12 extends inward in the tire radial direction Y from both ends of the tread 10 in the tire axial direction X. A rim strip 18 that forms an outer surface of the bead is provided adjacent to the sidewall 12 at the inner end of the tire 1 in the radial direction Y.

[0014] The tire 1 is a pneumatic tire filled with air at a predetermined pressure. The tread 10 is made of tread rubber. The sidewall 12 is made of a different type of sidewall rubber from the tread rubber.

[0015] In this specification, unless otherwise specified, the dimensions of each part of a tire are dimensions measured when an unused tire is mounted on a standard rim, filled with air to the standard internal pressure, and in a standard, unloaded condition.

[0016] "Ground contact end T" refers to both ends in the axial direction X of the tire in the area that comes into contact with a flat road surface when an unused tire 1 is mounted on a standard rim, inflated to the standard internal pressure, and subjected to a load that is 88% of the standard load at the standard internal pressure.

[0017] Here, a "regular rim" is a rim determined by the tire standard, which is a "standard rim" for JATMA, a "design rim" for TRA, and a "measuring rim" for ETRTO. "Regular internal pressure" is "maximum air pressure" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "INFLATION PRESSURE" for ETRTO. "Regular load" is "maximum load capacity" for JATMA, the maximum value listed in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES" for TRA, and "LOAD CAPACITY" for ETRTO.

[0018] The tire 1 includes a carcass, a belt layer, and an inner liner. The carcass is a cord layer covered with rubber, and forms the framework of the tire 1 that can withstand loads, impacts, air pressure, etc. The belt layer is a reinforcing band disposed between the tread rubber 11 and the carcass. The belt layer tightens the carcass to increase the rigidity of the tire 1. The belt layer is formed by overlapping multiple belts in the tire radial direction Y. Each belt is formed by covering multiple cords arranged in a direction inclined relative to the tire circumferential direction with rubber. In adjacent belts, the cords are inclined in opposite directions relative to the tire circumferential direction so that they cross each other. The cords are formed from steel or the like.

[0019] Between the belt layer and the tread rubber, a belt reinforcing layer is provided, which extends in the tire circumferential direction and covers the entire belt layer in the tire axial direction X. The belt reinforcing layer is formed by covering cords, which extend in the tire circumferential direction, with rubber. The cords are made of organic fibers or the like.

[0020] In the tire 1 of the embodiment, the mounting direction of the front and back of the tire 1 on the vehicle is specified. That is, the outer and inner sides of the vehicle are respectively specified for the tire 1. In Fig. 1, the tire 1 is mounted on the vehicle so that the right side is the outer side (OUT side) of the vehicle and the left side is the inner side (IN side) of the vehicle.

[0021] A symbol called a serial number is generally provided on the side of a tire. The serial number includes information such as a size code, manufacturing time (manufacturing year and week), and manufacturing location (manufacturing factory code). The mounting direction of the tire 1 on the vehicle can be specified by providing a serial number only on the tire side (sidewall 12) facing the outside of the vehicle, or by providing different serial numbers on the side facing the outside of the vehicle and the side facing the inside of the vehicle. A specific example is providing a manufacturing factory code and a size code on both sides of the tire 1, and providing the manufacturing year and week only on the side facing the outside in the width direction of the vehicle.

[0022] In addition, the side of the tire facing the outside of the vehicle may be provided with letters or symbols to indicate that it is on the outside when mounted on the vehicle.

[0023] In addition, a rim protector 19 that protrudes axially outward is provided as part of the rim strip rubber that forms the rim strip 18. The rim line 20 is provided in an annular shape along the circumferential direction of the tire at the apex located at the axially outer end of the rim protector 19. The rim protector 19 has the function of protecting the rim from external damage. The rim line 20 is a line for checking that the tire 1 is mounted on the rim in the correct position by checking the gap with the rim. Although the rim protector 19 is provided in FIG. 1, a configuration without the rim protector 19 is also possible, as shown by the two-dot chain line in FIG. 1. Even in this case, a rim line that is a protrusion formed in an annular shape and protruding axially outward is provided on the side of the tire to check that the tire 1 is mounted on the rim in the correct position.

[0024] In this example, a pattern forming portion including multiple protrusions is provided on a tire side surface 13, which is the outer surface in the tire axial direction X, located inside in the tire radial direction Y of the ground contact edge T of the tread 10 and outside in the tire radial direction Y of the rim line 20.

[0025] FIG. 2A is a diagram showing an annular portion 102 including two pattern-forming portions 100, 101 applied to a tire side surface 13 of a tire 1. FIG. 2B is an enlarged view of the upper portion of FIG. 2A. As shown in FIG. 2A and FIG. 2B, an annular portion 102 having a constant radial length over the entire circumference in the tire circumferential direction is provided on the tire side surface 13 facing the outside of the vehicle. The annular portion 102 includes two pattern-forming portions 100, 101 that are diametrically opposed to each other. The two pattern-forming portions 100, 101 have the same shape and are spaced apart from each other in the tire circumferential direction. Each of the two pattern-forming portions 100, 101 includes straight portions 103a, 103b, 103c, L-shaped portions 104a, 104b, 104c, V-shaped portions 105a, 105b, 105c, and concave portions 106a, 106b, which are pattern regions. Each pattern area has a shape based on straight lines.

[0026] As will be described in detail later, each pattern region has a plurality of protrusions disposed on the inside. As a result, each pattern forming portion 100, 101 is a portion in which a plurality of protrusions are disposed. Also, each of the plurality of protrusions is a polygonal shape having a first surface that is a smooth surface that serves as a light reflecting surface, and a second surface that is connected to the first surface at its apex and serves as a shadow. As a result, as will be described later, a strong contrast can be provided on the tire side surface 13 by the light reflecting surface and the shadow portion such as a black line, thereby realizing a tire 1 with a high design quality that can utilize light reflection to create an excellent sense of brilliance.

[0027] In this example, the total ratio of the tire circumferential lengths L1, L2 (FIG. 2A) of the pattern forming portions 100, 101 to the entire circumference of the sidewall 12 facing outward in the tire axial direction is 50% or more. This allows the pattern portions with strong contrast to stand out throughout the tire, further improving the design of the tire 1.

[0028] Fig. 3 is an enlarged view of a portion in the circumferential direction of the tire side surface 13 including part A in Fig. 2B, with the contrast between the reflective surface and the shadow part emphasized. Fig. 4 is an enlarged perspective view corresponding to part B in Fig. 3.

[0029] As shown in FIG. 2A and FIG. 2B, each pattern forming portion 100, 101 has a symmetrical shape on both sides in the tire circumferential direction with respect to the tire circumferential center of each pattern forming portion 100, 101. Each pattern forming portion 100, 101 includes multiple types of straight portions 103a, 103b, 103c with different widths and multiple types of L-shaped portions 104a, 104b, 104c with different widths. The straight portions 103a, 103b, 103c are inclined with respect to the tire circumferential direction. Each pattern forming portion 100, 101 also has two types of V-shaped portions 105a, 105b, 105c with different sizes and two types of concave portions 106a, 106b that open to the tire radial outside. A plurality of protrusions are formed on the inside of each shape portion. Even in the same type of pattern region, the size of the protrusions arranged on the inside and the pitch, which is the distance between the tops of the multiple protrusions, are different depending on the position, width, or size.

[0030] For example, as shown in FIG. 3 and FIG. 4, in three types of L-shaped parts 104a, 104b, and 104c with different widths, protrusions 30, 31, and 32 with different unit sizes and pitches are arranged. The following description focuses on the protrusions arranged in the L-shaped parts, but the same applies to protrusions arranged in other shaped parts such as straight parts. In the L-shaped part 104a with the smallest width, multiple protrusions 30 with the smallest unit size among the three types are arranged, and the pitch of the multiple protrusions 30 is also the smallest. In the L-shaped part 104c with the largest width, multiple protrusions 32 with the largest unit size among the three types are arranged, and the pitch of the multiple protrusions 32 is also the largest. In the L-shaped part 104b with an intermediate width, multiple protrusions 31 with the intermediate unit size among the three types are arranged, and the pitch of the multiple protrusions 31 is intermediate between the maximum pitch and the minimum pitch.

[0031] As shown in Fig. 4, the multiple protrusions 31, 32 are arranged inside the L-shaped portions 104b, 104c. As shown in Fig. 3 and Fig. 4, each of the L-shaped portions 104b, 104c includes a recess 109 having a shape in which a circumferential portion 108 extending in the tire circumferential direction is connected to one end of an inclined portion 107 extending in a straight direction inclined with respect to the tire circumferential direction, and multiple protrusions 31, 32 arranged inside the recess 109. The recess 109 is recessed from the sidewall reference surface 14 of the tire toward the tire inner surface, and extends in the extension direction of the inclined portion 107 or the circumferential portion 108 with approximately the same width.

[0032] The sidewall reference surface 14 means the surface of the sidewall 5 facing outward in the tire axial direction in a portion of the tire side surface 13 where no partial irregularities such as protrusions such as side blocks or recesses 109 are formed.

[0033] The multiple protrusions 31, 32 are formed so as to protrude from a bottom surface 110 of the recessed portion 109. The bottom surface 110 of the recessed portion 109 is a reference surface for forming the protrusions, and is a part of the tire side surface 13.

[0034] In the following, the protrusions will be described by using Figs. 5 to 9, taking the protrusion 31 arranged on the L-shaped portion 104b having an intermediate width as a representative. Fig. 5 is a view of part C in Fig. 4, seen from the outside in a direction perpendicular to the bottom surface 110 of the recess 109, which is the protrusion formation reference surface. Fig. 6 is a perspective view of the pattern forming portion 100 shown in Fig. 4, seen from a position approaching the tire side surface 13 and away in the tire circumferential direction. Fig. 7 is an enlarged perspective view of a part of the L-shaped portion 104b, which is the pattern region shown in Fig. 5, seen from the outside in the radial direction of the tire. Fig. 8 is a DD cross-sectional view of Fig. 4. Fig. 9 is an enlarged view of part E in Fig. 8.

[0035] FIG. 5 shows the recess 109 in the inclined portion 107 forming the L-shaped portion 104b and the protrusion 31 on the inside thereof. As shown in FIG. 5, the multiple protrusions 31 are aligned in a first direction K1 along the extension direction of the inclined portion 107. As shown in FIG. 7, each protrusion 31 has a polygonal shape having six sides, each having two first faces 33, two second faces 34, and two third faces 35. In addition, protrusions 31a having a part of the shape of the protrusion 31 are also aligned on both sides of each of the multiple protrusions 31 in the direction of the dashed line K2, which is a second direction slightly inclined with respect to the direction of the arrow J in FIG. 5, which is the tire circumferential direction. The protrusion 31a has a part of the shape of the protrusion 31, is cut by the wall surface 109a of the recess 109, and is connected to the wall surface 109a at the cut portion, and has a partial shape of a shape having six sides. The shape of the protrusion 31 having a shape having six sides will be described in detail below.

[0036] As shown in FIG. 5, each protrusion 31 has a second surface 34 that is two smooth surfaces that form a wide V shape when viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess 109. Also, as shown in FIG. 7, the first surface 33 is connected to the tire radial outer side of each second surface 34 by a ridge line 36 that serves as the apex. More specifically, each protrusion 31 is a polygonal shape having two identical rectangular first surfaces 33 (FIG. 7) that are connected to each other in a V shape and two identical rectangular second surfaces 34 that are connected to each of the two first surfaces 33 by ridge lines 36 and are connected to each other in a V shape. Also, each protrusion 31 has two identical triangular third surfaces 35 that are connected to both ends of the longitudinal direction along the V-shaped ridge line 36 direction. Each protrusion 31 has a symmetrical shape on both sides with respect to the center in the second direction (the direction of the dashed line K2 in FIG. 5). 5, the shape of each of the two second surfaces 34 when each protrusion 31 is viewed in a direction perpendicular to the bottom surface 110 of the recess 109 is a rhombus. The bottom surface 110 has a shape recessed from the sidewall reference surface 14 toward the inner surface of the tire 1 so as to follow the sidewall reference surface 14. The depth of the recess 109 to the bottom surface 110 can be generally uniform. Note that the cross-sectional view of the portion of the bottom surface 110 from which the first surface 33 and the second surface 34 rise can be a straight line.

[0037] 8 and 9, each first surface 33 of each protrusion 31 stands upright from bottom surface 110 of recess 109 at an angle α (FIG. 9) in the range of ±15% with respect to a surface S1 (FIG. 9) that stands upright at 90 degrees to bottom surface 110. Also, each second surface 34 of each protrusion 31 is connected to first surface 33 by a ridge 36, and stands up so as to be inclined with respect to bottom surface 110 at an angle β (FIG. 9) greater than 90 degrees + 15%.

[0038] 9 stands upright from the bottom surface 110 at the same angle α as the surface S1 standing upright at 90 degrees to the bottom surface 110, but may stand upright from the bottom surface 110 at an angle greater than 90 degrees or less than 90 degrees within a range of 90 degrees ±15%. Also, each second surface 34 of each protrusion 31 may stand upright at an angle greater than 90 degrees +30%, or more preferably, at an angle greater than 90 degrees +50%, to the bottom surface 110.

[0039] As a result, the second surfaces 34 form a light reflecting surface on the tire side surface 13, and the first surfaces 33 create shadow areas such as black lines, thereby providing a strong contrast to the tire side surface 13. This allows the tire side surface 13 to have an excellent sense of brilliance by utilizing the reflection of light, thereby realizing a tire 1 with excellent design. Also, as will be described later, at multiple positions on the bottom surface 110 shown in FIG. 5, a quadrangular portion such as a diamond shape can be formed in the portion surrounded by the four second surfaces 34. When the tire side surface 13 is viewed, this quadrangular portion has a brightness intermediate between the second surfaces 34 and the shadow areas such as black lines.

[0040] Height H (FIG. 9) of each protrusion 31 is, for example, 0.15 mm or more and 0.5 mm or less. For example, as shown in FIGS. 6 and 8, the vicinity of the apex of protrusion 31 can be made to protrude outward from opening end 109b of recess 109. For example, the portion including the apex of protrusion 31 can be made to protrude outward from opening end 109b by about 0.1 mm.

[0041] Here, unlike the embodiment, consider a case where each first surface 33 of each protrusion 31 stands upright from the bottom surface 110 of the recess 109 at an angle exceeding +15% with respect to the surface S1 standing perpendicular at 90 degrees to the bottom surface 110 of the recess 109 (for example, as shown by the dashed dotted line γ in FIG. 9 , the angle between the surface S1 and the bottom surface 110 is greater than θ1, which is an angle of +15% with respect to the 90-degree surface S1). In this case, the increase rate of brightness due to the first surface 33 exceeds 15%, making it difficult to produce a contrast between light and dark on the tire side surface 13.

[0042] Also, unlike the embodiment, consider a case where each first surface 33 of each protrusion 31 stands upright from bottom surface 110 of recess 109 at an angle of less than -15% based on a plane that stands upright at 90 degrees to bottom surface 110 (for example, as shown by the dashed dotted line δ in FIG. 9, the angle between bottom surface 110 and the plane S1 of 90 degrees is smaller than θ2, which is an angle of -15% based on the plane S1). In this case, the so-called under angle becomes larger and the difference in brightness on the tire side surface 13 becomes larger, but there is a possibility that the rubber will tear when the molded tire is removed from the mold during molding of the tire, reducing moldability.

[0043] As in the embodiment, each first surface 33 of each protrusion 31 is erected from the bottom surface 110 of the recess 109 at an angle within a range of ±15% based on the surface S1 that stands perpendicular at 90 degrees to the bottom surface 110, thereby preventing such inconveniences, making it easier to create a difference in light and dark on the tire side surface 13, and maintaining good moldability of the tire 1.

[0044] As shown in FIG. 5 and other figures, when viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess 109, the ridges 36 of the second surfaces 34 of two adjacent protrusions 31 in the first direction (the direction of the dashed line K1 in FIG. 5) are aligned parallel to each other. In addition, the ridges 36 of the second surfaces 34 on the other side in the second direction (the right side in FIG. 5) of the protrusion 31 on one side in the first direction (the lower side in FIG. 5) and the protrusion 31a adjacent to one side in the second direction (the left side in FIG. 5) of the protrusion 31 on the other side in the first direction (the upper side in FIG. 5) are aligned parallel to each other. At this time, the two protrusions 31, 31a adjacent to each other in the second direction face each other with a minute gap of, for example, about 0.1 mm between them. The line of this minute gap forms a black line, which can highlight the contrast with the reflective surface.

[0045] In this state, when viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess 109, a rhombus is formed on the bottom surface 110 in the portion surrounded by the three protrusions 31, 31a, and the rhombus is arranged so that a plurality of the rhombus is lined up at least in the first direction. As a result, a regular pattern can be formed inside at least a portion of the pattern region including the inclined portion, in which the rhombus formed by one second surface 34 of the protrusion 31 and the rhombus on the bottom surface 110 are alternately arranged along the first direction. Note that, by widening the width of the inclined portion or reducing the size of each protrusion 31 in at least a portion of the pattern region including the inclined portion, the protrusions 31 having a shape with a plurality of six faces can also be lined up in each of the first direction and the second direction that intersect with each other.

[0046] In addition, some pattern areas such as the L-shaped portions 104a, 104b, 104c and the recessed portions 106a, 106b have circumferential portions extending in the tire circumferential direction, and in the circumferential portions, protrusions 31 having a shape with multiple six sides are arranged along a second direction inclined with respect to the tire circumferential direction.

[0047] 10 is a diagram showing the shape of a part of a pattern area of ​​a tire side surface 13 in an embodiment, as viewed from the outside in a direction perpendicular to a bottom surface 110 of a recess. The pattern area is not limited to the L-shaped portion 104b. For convenience of explanation, the protrusions in FIG. 10 will be explained as protrusions 31. In FIG. 10, the bottom surface 110 is indicated by a sandy portion. Also, the thick straight line portion d indicates the gap between adjacent protrusions 31.

[0048] As shown in FIG. 10, the minimum distance between intersections G of ridges 36 of two second faces 34, which are the vertices of each protrusion 31, is defined as the pitch P. The pitch P is, for example, 1.0 mm or more and 5.0 mm or less. The pitch P2 of the L-shaped portion 104b shown in FIG. 4 and FIG. 5 is the intermediate pitch of the three types of L-shaped portions. The intermediate pitch is, for example, 2.0 mm. The pitch P1 of the L-shaped portion 104a shown in FIG. 3 and FIG. 6 is the minimum pitch of the three types of L-shaped portions. The minimum pitch is, for example, 1.0 mm. The pitch P3 of the L-shaped portion 104c shown in FIG. 4 and FIG. 6 is the maximum pitch of the three types of L-shaped portions. The maximum pitch is, for example, 3.0 mm. Furthermore, L-shaped portion 104a, L-shaped portion 104b, and L-shaped portion 104c correspond to a first pattern region, a second pattern region, and a third pattern region, respectively, and have different pitches P1, P2, and P3. Pitch P is used as a general term for multiple types of pitches.

[0049] Similarly to the L-shaped portion, the concave portions 106a and 106b shown in FIG. 2B have two different pattern regions with different widths, and the pitches P of the multiple protrusions are different. On the other hand, the pitches P of the multiple protrusions may be made the same in the multiple pattern regions with different widths. For example, the three straight line portions 103a, 103b, and 103c shown in FIG. 2B and FIG. 3 have different widths, but the pitches P of each of them are made the same as the pitch P1 of the L-shaped portion 104a. In FIG. 2B, the pattern region having the smallest pitch P1 is indicated by PA1, the pattern region having the largest pitch P3 is indicated by PA3, and the pattern region having the intermediate pitch P2 is indicated by PA2. Since the pitches P of the multiple protrusions are different in the multiple pattern regions, as shown in FIG. 3, it is possible to produce different brilliance at multiple positions on the tire side surface 13 due to the difference in the intervals of the second surface that serves as the reflective surface. As the pitch P becomes larger, when the gap between adjacent protrusions is kept as small as 0.1 mm, the area of ​​the second surface corresponding to the pitch P can be increased, making it easier to make the second surface shine. Conversely, as the pitch P becomes smaller, the second surface corresponding to the pitch P becomes less likely to shine. This makes it easier to create contrast on the tire side surface 13 by varying the ease of shining in different pattern areas, thereby further improving the design.

[0050] 10, when the pitch P is 1, the longitudinal dimensions Lb, Lc of the diamond of each second surface 34 as viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess are preferably 0.8 or more and 1.2 or less. When Lb, Lc is less than 0.8, the highlighted portion is greatly reduced. On the other hand, when Lb, Lc exceeds 1.2, the highlighted portion is greatly increased compared to the bottom surface 110, which has a lower brightness than the second surface 34, so that it is difficult to generate a difference in brightness on the tire side surface 13. Note that Lb, Lc may be different from each other.

[0051] 10, when the pitch P is 1, it is preferable that the short-side dimension Ld of the diamond of the bottom surface 110 of the recess 109 when viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess 109 is 0.5 or more and 0.7 or less. If Ld is less than 0.5, the area of ​​the diamond portion with low brightness is significantly reduced. On the other hand, if Ld exceeds 0.7, the area of ​​the diamond portion with low brightness is too large compared to the highlight portion, and the effect of the highlight portion on the tire side surface 13 is reduced.

[0052] Returning to FIG. 8, the protrusion pitch ratio P / H, which is the ratio between the pitch P of adjacent protrusions 31 and the height H of the protrusions 31, is 2 or more and 14 or less. More preferably, the protrusion pitch ratio P / H is 2 or more and 10 or less, and even more preferably, the protrusion pitch ratio P / H is 2 or more and 6 or less. This allows the position where the airflow separates from the tire side surface 13 to be shifted further downstream, toward the rear in the tire traveling direction. This allows the width of the wake region formed on the downstream side of the airflow of the tire 1 and where the speed of the airflow is reduced to be reduced, thereby suppressing an increase in the air resistance of the tire 1. In addition, by making the protrusion pitch ratio P / H 2 or more, when the gap between adjacent protrusions 31 is kept very small, such as 0.1 mm, the area of ​​the second surface 34 can be increased while suppressing an increase in the height of the protrusions 31, thereby enhancing the light reflection effect. The larger the protrusion pitch ratio P / H, the higher the light reflection effect can be.

[0053] FIG. 11 is a schematic diagram showing that, in an embodiment, after an airflow indicated by an arrow U1 collides with a protrusion 31 on a bottom surface 110, the airflow reattaches to another protrusion 31 on the downstream side due to turbulence, and the separation point is likely to be located downstream. In the embodiment, the above-mentioned protrusion pitch ratio P / H is 2 or more and 6 or less, so that the airflow that collides with the protrusion 31 on the bottom surface 110 becomes turbulent and moves downstream, and the turbulent flow collides again with another protrusion 31 on the downstream side, and this is repeated. As a result, the separation point of the airflow on the tire side surface 13 is likely to shift downstream. Therefore, as described later, on the downstream side of the airflow of the tire, the width of the wake region that is formed by the part sandwiched from both sides by the separated flow of air from the separation position on the tire side surface 13 and becomes negative pressure can be reduced. Therefore, the pressure resistance due to the formation of the protrusion 31 can be reduced, and an increase in air resistance can be suppressed.

[0054] FIG. 12 is a schematic diagram showing that in another example configuration in which the projection pitch ratio P / H is less than 2, the surface of the projections 31b does not generate turbulence, similar to a smooth surface. When the projection pitch ratio P / H is less than 2, as shown in FIG. 12, the density of the multiple projections 31b per unit area of ​​the tire side surface 13 increases. As a result, the tire side surface 13 becomes similar to a smooth surface in relation to the airflow indicated by the arrow U2, making it difficult for turbulence to occur in the airflow. For this reason, the separation point of the airflow on the tire side surface 13 is unlikely to shift downstream. Therefore, the effect of reducing negative pressure is reduced, and the effect of suppressing an increase in air resistance is reduced.

[0055] On the other hand, if the protrusion pitch ratio P / H exceeds 14, the amount of protrusions 31 formed on the tire side surface 13 decreases, and the effect of reducing negative pressure decreases. In this case as well, the effect of suppressing an increase in air resistance decreases. From the viewpoint of suppressing an increase in air resistance of the tire 1, it is more preferable that the protrusion pitch ratio P / H be 2 or more and 6 or less.

[0056] The effects of the embodiment will be described in more detail with reference to Fig. 13 and Fig. 14. Fig. 13 is a schematic diagram showing, by simulating a cylinder Sa, the generation of a wake region 40 due to a separated air flow downstream of the air flow from a tire side surface 13 in another example configuration in which the protrusion pitch ratio is less than 2. In Fig. 13, many turbulent flows are formed inside the wake region 40. In Fig. 13 and Fig. 14, the tire is shown simulated by a cylinder Sa.

[0057] In another example shown in FIG. 13, the above-mentioned projection pitch ratio is less than 2, so that the tire side surface 13 does not generate turbulence as in the case of a smooth surface. In this case, consider that an air flow shown by a broken line collides with the surface of the cylinder Sa as the tire side surface 13 as the vehicle rotates during running. In this case, a positive pressure is generated on the air flow upstream side of the cylinder Sa so as to press the cylinder Sa downstream. Then, when the air flow flows from the air flow upstream side of the cylinder Sa to the downstream side along the surface of the cylinder Sa, the air flow separates from the surface of the cylinder Sa at positions C1 and C2 in FIG. 13. Then, a wake region 40 where negative pressure is generated is formed by a portion sandwiched from both sides by the separated air flows from the separation position of the cylinder Sa. In the case of FIG. 13, the width (vertical length in FIG. 13) of this wake region 40 is large, so the effect of reducing the negative pressure is small. For this reason, when the projection pitch ratio is less than 2, the effect of suppressing the increase in pressure resistance in the tire is low, so the effect of suppressing the increase in air resistance is small.

[0058] Fig. 14 is a schematic diagram showing, by using a cylinder S, how the width of the wake region 40 caused by the separated air flow narrows downstream of the air flow from the tire side surface 13, thereby enhancing the effect of reducing negative pressure in the embodiment. In Fig. 14, the formation of multiple protrusions 31 on the tire side surface 13 on both sides in the tire axial direction is simulated by small protrusions formed on the surface of the cylinder S.

[0059] As shown in FIG. 14, in the embodiment, since the projection pitch ratio is 2 or more and 14 or less, the separation point of the airflow from the tire side surface 13 is likely to shift to downstream positions C3 and C4 for the reasons described in FIG. 11. This makes it possible to reduce the width of the wake region 40 that is formed on the downstream side of the cylinder S simulating the tire, in a portion sandwiched from both sides by the separated flow of air from the separation position on the surface of the cylinder S and becomes negative pressure. FIG. 14 simulates the formation of multiple projections 31 on the tire side surface 13 on both sides in the tire axial direction, but even if multiple projections having first and second surfaces are formed only on the tire side surface 13 on the vehicle outer side as in the embodiment, the width of the wake region 40 is reduced. As a result, in the embodiment, the effect of suppressing the increase in pressure resistance in the tire is enhanced, and the increase in air resistance can be suppressed.

[0060] In addition, the multiple protrusions may be formed on the tire side surface 13 within a tire radial direction Y range (the range indicated by the arrow η in FIG. 1 ) that is 25% or more and 65% or less when the tire radial direction position of the rim line 20 is set to 0 and the tire cross-sectional height Ht is set to 100.

[0061] According to this configuration, the protrusions can be provided in the range from the vicinity of the outer end in the tire axial direction (P in FIG. 1) of the tire side surface 13 corresponding to the maximum tire width, that is, the outer portion in the tire radial direction Y, where the air flow is likely to hit, to the outer peripheral portion of the tire, which is easily noticeable and has a high effect of improving the design.

[0062] Fig. 15 is a cross-sectional view showing a tire molding die of an embodiment. Fig. 16 is a perspective view showing a part of a portion in which recesses 80 corresponding to a plurality of protrusions of the tire molding die are formed in the embodiment. The pneumatic tire of this embodiment is formed by a tire molding die 70. Hereinafter, the tire molding die 70 will be referred to as the die 70. The die 70 is a die for molding the tire 1 shown in Figs. 1 to 10 described above. The die 70 can provide an excellent sense of sparkle on the tire side surface 13 by utilizing light reflection, thereby realizing a tire with excellent design.

[0063] Hereinafter, each member will be described according to the tire axial direction X and tire radial direction Y of the tire 1 described above formed by the mold 70.

[0064] The mold 70 has a tread mold 71 for molding the surface of the tread of the tire 1, and a pair of side molds 72 for molding the surfaces of the sidewalls.

[0065] The tread mold 71 has a body 74 having a tread molding surface 73 , and a protrusion 75 protruding from the tread molding surface 73 .

[0066] The main body 74 is made of a metal material, for example, an aluminum alloy. As the aluminum alloy, for example, AC4 series, AC7 series, etc. are preferably used. The protrusion 75 is a portion that forms a circumferential groove in the tire 1. The protrusion 75 is made of the same material as the metal material that constitutes the main body 74.

[0067] The side mold 72 has a main body 76 having side molding surfaces 77a, 77b, and the side molding surface 77a for forming the tire side surface on the outer side of the vehicle has a plurality of protrusions 78 protruding outward from the side molding surface 77a. The main body 76 is made of the same metal material as the main body 74. The plurality of protrusions 78 are portions that form a plurality of recesses 109 in the tire 1, each of which has a plurality of projections protruding from a bottom surface 110.

[0068] The tread mold 71 is a sector shape in a plan view formed by dividing an annular body into several parts in the circumferential direction. The tread mold 71 divided into several parts forms a continuous body in an annular shape so as to have an inner diameter corresponding to the outer diameter of the tire 1 to be molded in a mold clamped state described later. The upper side mold 72 is annular, fixed to the lower surface of an upper plate (not shown) constituting the vulcanization molding machine, and rises and falls with the rise and fall of a first lifting member (not shown). The lower side mold 72 is annular, fixed to the floor surface, and fixed to the lower surface of a lower plate (not shown) constituting the vulcanization molding machine. The vulcanization molding machine raises and lowers a plurality of segments (not shown) provided one for each tread mold 71 on the outside of the tread mold 71 divided into several parts by the first lifting member. At the same time as the first lifting member rises and falls, the vulcanization molding machine slides and moves the inclined surfaces of the outer peripheral surfaces of the plurality of segments in the vertical direction on an inclined cylindrical surface provided at the lower end of a second lifting member (not shown) that rises and falls independently of the first lifting member. As a result, the vulcanization molding machine reciprocates the multiple segments in the radial direction relative to the central axis of the annularly continuous tread mold 71. As a result, the vulcanization molding machine switches the mold 70 between a mold clamped state and a mold open state.

[0069] In the mold 70 thus configured, a green tire is placed on the lower tread mold 71 so that the tire axial direction is aligned vertically in the mold open state. Then, an inflatable bladder is placed inside the green tire, and the bladder is inflated by supplying air to the bladder. Then, while the outer surface of the bladder holds the inner surface of the green tire, the first lifting member and the second lifting member are raised and lowered to close the mold 70. The rubber of the green tire is pressed against the tread molding surface 73 and the side molding surfaces 77a, 77b by the pressure from the mold 70, and a heat exchange medium adjusted to a predetermined temperature is constantly flowed between the member fixing the upper plate and the member fixing the lower plate. This causes the rubber of the green tire to be vulcanized, and a tire 1 of a predetermined shape is completed.

[0070] In this embodiment, a plurality of protrusions 78 for forming a recess 109 with a plurality of protrusions protruding are formed on a side molding surface 77a for forming the tire side surface 13 on the vehicle outer side. The top surface of the protrusion 78 corresponds to the bottom surface 110 of the recess 109.

[0071] As shown in FIG. 16, a plurality of recesses 80 corresponding to a plurality of protrusions provided on the tire side surface 13 are formed on the top surface 78a of the protrusion 78. The recesses 80 are recessed from the top surface 78a in a substantially V-shape, and have a shape corresponding to the protrusion having six sides. Specifically, the recess 109 has two rectangular first faces 83 that are continuous in a V-shape when viewed in a direction perpendicular to the top surface 78a, two rectangular second faces 84 that are connected to each of the first faces 83 by a valley line of the valley, and two triangular third faces 85 provided at both ends of the recess 80 in the longitudinal direction. The first face 83, the second face 84, and the third face 85 of the recess 80 respectively form the first face 33, the second face 34, and the third face 35 of the protrusion of the tire 1.

[0072] The multiple recesses 80 of the mold can be formed by drilling holes in the top surfaces 78a of the protrusions 78 of the mold. For example, the drilling can be performed by NC machining using a cutting tool such as an end mill, laser machining, or electric discharge machining.

[0073] FIG. 17 is a cross-sectional view showing a plurality of protrusions 31, 31c formed to protrude from different surfaces of the tire side surface 13a in a tire according to another embodiment. In the configuration of this example, the tire side surface 13a has a plurality of protrusions 31 protruding from the bottom surface 110 of the recess 109 and a plurality of protrusions 31c protruding from the sidewall reference surface 14 on the outer side of the recess 109. The shapes of the plurality of protrusions 31, 31c are the same as the protrusions 31 formed in the tire 1 shown in FIGS. 1 to 10. In this example, the reflection of light by the reflective surface of the protrusions 31c on the sidewall reference surface 14 becomes more noticeable. Therefore, it is easier to give contrast to the tire side surface 13c. In this case, the height of the protrusions 31c on the sidewall reference surface 14 is greater than the height of the protrusions 31 protruding from the bottom surface 110 of the recess 109. For this reason, it is preferable to have the protrusions 31 protrude from the bottom surface 110 of the recess 109 as in the configuration shown in FIGS. 1 to 10 in terms of suppressing an increase in air resistance. In the configuration of this example, the protrusion 31 in the recess 109 may be omitted, and only a plurality of protrusions 31c may be formed on the sidewall reference plane 14 on the tire side surface 13. In this example, other configurations and functions are similar to those of FIGS. 1 to 10, 15, and 16.

[0074] FIG. 18 is a view corresponding to FIG. 2B in a tire according to another embodiment. In this example, an annular portion 112 including two pattern-forming portions 111 applied to the tire side surface 13 is provided. FIG. 18 shows only one of the two pattern-forming portions 111. The two pattern-forming portions 111 have the same shape and are spaced apart from each other in the tire circumferential direction. Each pattern-forming portion 111 has a plurality of pattern regions 113, 114, 115, 116, 117, and 118 based on a curve including a plurality of spiral portions. Each of the plurality of pattern regions has a plurality of curved portions with different widths. The plurality of curved portions have a plurality of recesses along the longitudinal direction of the curve, and a plurality of protrusions are formed so as to rise from the bottom surface of each recess 9. The shape of each protrusion formed on the curved portion is the same as the protrusion 31 formed on the tire 1 shown in FIGS. 1 to 10. The plurality of protrusions may be arranged distributed in the curved direction instead of being arranged in a straight line. In addition, the plurality of protrusions may be arranged in the same direction in the tire circumferential direction or in a direction inclined relative to the tire circumferential direction. In this example, other configurations and functions are similar to those in Figures 1 to 10, 15, and 16.

[0075] Although not shown in the figures, as another example of the embodiment, the multiple protrusions of the same shape arranged on the tire side surface may be two or more types of protrusions arranged in different directions in the tire circumferential direction or in a direction inclined to the tire circumferential direction. In this case, it is possible to produce different senses of brilliance at multiple positions on the tire side surface due to different orientations of the second surface, which serves as a reflective surface, without changing the size of the protrusions or the pitch of the multiple protrusions. This also improves the design of the tire side surface.

[0076] In the above embodiment, protrusions having a first surface and a second surface, such as protrusion 31, are formed only on the tire side surface 13 facing the outside of the vehicle, but a configuration in which the mounting direction of the tire is not specified may be adopted by forming protrusions on the tire side surfaces on both sides of the vehicle.

[0077] Also, the protrusion arrangement area may be formed over the entire tire circumferential direction of the tire side surface, or the protrusion arrangement area may be formed in three or more separate positions in the tire circumferential direction. Also, a plurality of protrusions may be formed in a line in the tire circumferential direction or in a direction inclined at a predetermined angle to the tire circumferential direction. This makes it easier to reduce air resistance on the tire side surface. Meanwhile, by randomly arranging a plurality of protrusions on the tire side surface, it becomes easier to reduce air resistance in response to various changes in the tire travel direction, tire rotation direction, and wind flow in the direction of wind blowing up near the contact surface.

[0078] In the above embodiment, the protrusion provided on the tire side surface is a polygonal shape having six sides including two first sides and two second sides, but the protrusion may be a polygonal shape having at least one first side and one second side. For example, the protrusion may have only one first side erected from the tire side surface at an angle in the range of ±15% based on a surface standing upright at 90 degrees to the tire side surface, and only one second side connected at its apex to the first side and rising so as to be inclined at an angle greater than 90 degrees + 15% to the tire side surface, and may be a polygonal shape having four sides including third sides at both ends.

[0079] The present disclosure is further illustrated by the following embodiments. Configuration 1: A plurality of protrusions formed on the tire side surface, which is the axially outer surface of the tire, on the tire radially inner side of the ground contact edge of the tread and on the tire radially outer side of the rim line, Each of the multiple protrusions has a polygonal shape having a first surface that stands upright from the tire side surface at an angle in the range of ±15% based on a surface that is perpendicular to the tire side surface at 90 degrees, and a second surface that is connected to the first surface at its apex and rises up so as to be inclined at an angle greater than 90 degrees + 15% with respect to the tire side surface. Configuration 2: Each of the plurality of protrusions is polygonal in shape having two identical rectangular first surfaces connected to each other in a V-shape, two identical rectangular second surfaces connected to each of the two first surfaces and connected to each other in a V-shape, and two identical triangular third surfaces connected to both ends of the longitudinal direction along the ridge line direction of the V-shape, and each of the two second surfaces has a rhombus shape when viewed in a direction perpendicular to the tire side surface. 2. A pneumatic tire according to claim 1. Configuration 3: A method for manufacturing a semiconductor device comprising the steps of: providing a first pattern area and a second pattern area; and a pitch that is a distance between apexes of a plurality of the protrusions arranged in the first pattern area is different from a pitch that is a distance between apexes of a plurality of the protrusions arranged in the second pattern area. 3. A pneumatic tire according to claim 1 or 2. Configuration 4: The plurality of protrusions having the same shape and arranged on the tire side surface include two or more types of protrusions arranged in different directions in the tire circumferential direction or in a direction inclined relative to the tire circumferential direction. The pneumatic tire according to any one of the first to third aspects. Configuration 5: The plurality of protrusions are formed on the tire side surface so as to protrude from a bottom surface of a recess that is recessed from a sidewall reference plane toward the tire inner surface. The pneumatic tire according to any one of the first to fourth aspects. Configuration 6: The ratio P / H of the pitch P, which is the distance between the apexes of adjacent projections, to the height H of the projections, is 2 or more and 14 or less. The pneumatic tire according to any one of the first to fifth aspects. Configuration 7: The ratio P / H is 2 or more and 10 or less. 7. A pneumatic tire according to claim 6. Configuration 8: The ratio P / H is 2 or more and 6 or less. 8. A pneumatic tire according to claim 7. Configuration 9: The ratio of the total circumferential length of the portion where the plurality of protrusions are arranged to the entire circumference of the sidewall is 50% or more. The pneumatic tire according to any one of the first to eighth aspects. Configuration 10: The protrusion is formed on the tire side surface within a tire radial range of 25% to 65% when the tire radial position of the rim line is 0 and the tire cross-sectional height is 100. The pneumatic tire according to any one of the first to ninth aspects. Configuration 11: A pneumatic tire molding die for molding the pneumatic tire according to any one of configurations 1 to 10, A mold for molding a pneumatic tire has a molding surface having a plurality of recesses corresponding to the plurality of protrusions. [Explanation of symbols]

[0080] 1 pneumatic tire (tire), 10 tread, 12 sidewall, 13, 13a, 13b tire side surface, 14 sidewall reference surface, 18 rim strip, 19 rim protector, 20 rim line, 30, 31, 32, 31a, 31b, 31c protrusion, 33 first surface, 34 second surface, 35 third surface, 36 ridge, 40 wake region, 70 tire molding mold, 71 tread mold, 72 side mold, 73 tread molding surface, 74 main body, 75 protrusion, 76 main body, 77a, 77b side molding surface, 78 protrusion, 78a top surface, 80 recess, 100, 101 pattern forming portion, 102 annular portion, 103a, 103b straight portion, 104a, 104b, 104c L-shaped part, 105a, 105b V-shaped part, 106a, 106b concave part, 107 inclined part, 108 circumferential part, 109 concave part, 109a wall surface, 109b open end, 110 bottom surface, 111 pattern forming part, 112 annular part, 113,114,115,116,117,118 Pattern area, T ground edge.

Claims

1. The tire has a plurality of protrusions formed on a tire side surface, which is an axially outer surface of the tire, on the inner side of the ground contact edge of the tread and on the outer side of the rim line in the tire radial direction, Each of the plurality of protrusions has at least one first surface erected from the tire side surface at an angle in the range of ±15% based on a surface standing upright at 90 degrees to the tire side surface, and at least one second surface connected to the first surface at an apex and rising so as to be inclined at an angle greater than 90 degrees + 15% with respect to the tire side surface, and has a polygonal shape having two identical rectangular first surfaces connected to each other in a V-shape, two identical rectangular second surfaces connected to each of the two first surfaces and connected to each other in a V-shape, and two identical triangular third surfaces connected to both ends of the longitudinal direction along the ridge line direction of the V-shape, each of the two second surfaces has a rhombus shape when viewed in a direction perpendicular to the tire side surface, and the two first surfaces and the two second surfaces face in different directions from each other. Pneumatic tires.

2. The projections have a first pattern region and a second pattern region, and a pitch between apexes of the plurality of projections arranged in the first pattern region is different from a pitch between apexes of the plurality of projections arranged in the second pattern region. The pneumatic tire according to claim 1.

3. the plurality of protrusions having the same shape and arranged on the tire side surface include two or more types of protrusions arranged in different directions in the tire circumferential direction or in a direction inclined relative to the tire circumferential direction; The pneumatic tire according to claim 1.

4. The plurality of protrusions are formed on the tire side surface so as to protrude from a bottom surface of a recess that is recessed from a sidewall reference plane toward an inner surface of the tire. The pneumatic tire according to claim 1.

5. a ratio P / H of a pitch P, which is a distance between the apexes of adjacent protrusions, to a height H of the protrusions is 2 or more and 14 or less; The pneumatic tire according to claim 1.

6. The ratio P / H is 2 or more and 10 or less; The pneumatic tire according to claim 5.

7. The ratio P / H is 2 or more and 6 or less; The pneumatic tire according to claim 6.

8. The ratio of the total circumferential length of the portion where the plurality of protrusions are arranged to the entire circumference of the sidewall is 50% or more. The pneumatic tire according to claim 1.

9. the protrusion is formed on the tire side surface within a tire radial range of 25% to 65% when the tire radial position of the rim line is set to 0 and the tire cross-sectional height is set to 100; The pneumatic tire according to claim 1.

10. A mold for molding a pneumatic tire for molding the pneumatic tire according to any one of claims 1 to 9, A mold for molding a pneumatic tire has a molding surface having a plurality of recesses corresponding to the plurality of protrusions.

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