Pneumatic tire and pneumatic tire mold

Abstract

To provide a pneumatic tire having high design quality by providing glitter based on a strong contract to a 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 that is an outward surface in a tire axial direction located further inward in a tire radial direction than a ground contact end of a tread and further outward in the tire radial direction than a rim line. Each protrusion 31 has a polygonal shape having a first surface 33 rising from the tire side surface 13 at an angle within ±15% with respect to a plane rising at 90° with respect to the tire side surface 13, and a second surface 34 connected to the first surface 33 at a top and rising to be inclined with respect to the tire side surface 13 at an angle of greater than 90°+15%.SELECTED DRAWING: Figure 6

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, providing multiple protrusions on the tire side surface has been considered to improve the design of tires. For example, Patent Document 1 describes that multiple 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 states that this allows an optimal air relaxation layer to be formed on the tire surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-169827 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 conceivable to create a sense of brightness based on strong contrast on the tire side surface. However, the configuration described in Patent Document 1 does not take into consideration the creation of such a sense of brightness, and there is room for improvement in terms of realizing a tire with excellent design.

[0005] An object of the present invention is to provide a pneumatic tire and a mold for molding the same that have high designability by imparting a shiny appearance based on strong contrast to the tire side surface. [Means for solving the problem]

[0006] The pneumatic tire of the present invention comprises a plurality of protrusions formed on the tire side surface, which is the axially outer surface of the tire, radially inward of the ground-contact edge of the tread and radially outward of 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 its 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 mold according to the present invention is a pneumatic tire mold 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. [Effects of the Invention]

[0008] With the pneumatic tire and pneumatic tire mold according to the present invention, the second surface forms a light-reflecting surface on the tire side surface, and the first surface creates a shadow such as a black line, thereby providing a strong contrast to the tire side surface. This makes it possible to create an excellent shine on the tire side surface by utilizing the reflection of light, thereby realizing a tire with excellent design. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a diagram showing a tire contour shape in a meridian cross section of a pneumatic tire that is an example of an embodiment, and is a diagram showing the ranges in which a plurality of protrusions are formed. FIG. [Figure 2A] 1 is a diagram showing an annular portion including two pattern-forming portions formed on 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. [Figure 3] 2C is an enlarged view of a portion of the tire side surface in the circumferential direction, including part A in FIG. 2B, with the contrast between the reflective surface and the shadow area emphasized. [Figure 4] FIG. 4 is an enlarged perspective view corresponding to a portion B in FIG. [Figure 5] 5 is a view of part C in FIG. 4 as seen from the outside in a direction perpendicular to the projection 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] FIG. 6 is an enlarged perspective view of a part of the pattern area shown in FIG. 5 as viewed from the radially outer side of the tire. [Figure 8] FIG. 5 is a cross-sectional view taken along the line DD in FIG. 4. [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 region 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] FIG. 10 is a schematic diagram showing that, after an airflow collides with a protrusion, turbulence causes the airflow to reattach to another protrusion downstream, and the separation point is likely to be located downstream in an embodiment. [Figure 12] FIG. 10 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. [Figure 13] FIG. 10 is a schematic diagram illustrating, using a cylinder Sa, the generation of a wake region due to separated airflow downstream of the tire side surface in the airflow in another example configuration in which the protrusion pitch ratio is less than 2. [Figure 14] FIG. 10 is a schematic diagram illustrating, using a cylinder S as a simulation, how the width of the wake region caused by the separated air flow narrows downstream of the tire side surface in the air flow, increasing the negative pressure reduction effect 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 mold for molding a pneumatic tire in which recesses corresponding to a plurality of protrusions are formed in an embodiment. [Figure 17] FIG. 10 is a cross-sectional view showing a plurality of protrusions formed so as to protrude from different surfaces of the tire side surface in a pneumatic tire according to another example of the embodiment. [Figure 18] FIG. 3 is a view corresponding to FIG. 2B of a pneumatic tire according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an example of an embodiment of a pneumatic tire and a mold for molding the same 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. Furthermore, 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 the tire contour shape in a meridian cross section of a pneumatic tire 1 according to an embodiment, illustrating the ranges in which multiple protrusions are formed. As shown in FIG. 1, the pneumatic tire 1 includes a tread 10, which is the portion that comes into contact with the road surface. Hereinafter, the "pneumatic tire 1" will be referred to as the "tire 1." The tread 10 has a tread pattern including multiple 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 multiple blocks separated in the tire axial direction X. The multiple blocks are separated by circumferential grooves extending in the tire circumferential direction. The tread 10 has a ground contact edge 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) of the tire 1 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, which will be 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 the 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 than 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, inflated to a standard internal pressure, and in a standard, unloaded state.

[0016] "Touching edge 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 and inflated to the standard internal pressure, and a load of 88% of the standard load at the standard internal pressure is applied.

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

[0018] The tire 1 comprises a carcass, a belt layer, and an inner liner. The carcass is a cord layer covered with rubber, and forms the skeleton 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 multiple cords arranged in a direction inclined relative to the tire circumferential direction and covered with rubber. The cords of adjacent belts 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] A belt reinforcing layer is provided between the belt layer and the tread rubber, extending in the tire circumferential direction and covering the entire belt layer in the tire axial direction X. The belt reinforcing layer is formed by covering cords extending substantially 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 date (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 to provide a manufacturing factory code and a size code on both sides of the tire 1, and provide the manufacturing year and week only on the side facing the outside of the vehicle width direction.

[0022] In addition, a marking such as a letter or symbol may be provided on the side of the tire facing outward from the vehicle to indicate that the tire is on the outside when mounted on the vehicle.

[0023] Furthermore, 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 of the rim protector 19 that is located at the axially outer end of the tire. The rim protector 19 has the function of protecting the rim from external damage. The rim line 20 is a line that can be used to check the gap between the tire 1 and the rim to ensure that the tire 1 is properly mounted on the rim. Although the rim protector 19 is provided in Figure 1, the configuration may also be such that the rim protector 19 is not provided, as indicated by the two-dot chain line in Figure 1. Even in this case, a rim line, which is a circular protrusion that protrudes axially outward, is provided on the side of the tire to ensure that the tire 1 is properly mounted on the rim.

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

[0025] FIG. 2A is a diagram showing an annular portion 102 including two pattern-forming portions 100, 101 formed on 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 FIGS. 2A and 2B, an annular portion 102 having a constant radial length over the entire circumference of the tire is provided on the tire side surface 13 facing the outboard side 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 a plurality of pattern regions, namely, straight portions 103a, 103b, 103c, L-shaped portions 104a, 104b, 104c, V-shaped portions 105a, 105b, 105c, and concave portions 106a, 106b. Each pattern area has a shape based on straight lines.

[0026] As will be described in detail later, each pattern region has multiple protrusions arranged on the inside. As a result, each pattern forming portion 100, 101 is a portion where multiple protrusions are arranged. Furthermore, each of the multiple protrusions is polygonal, having a first surface that is a smooth surface that reflects light, and a second surface that is connected to the first surface at its apex and forms a shadow. As a result, as will be described later, a strong contrast can be created on the tire side surface 13 between the light reflecting surface and the shadow areas such as black lines, 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 FIGS. 2A and 2B , each pattern portion 100, 101 is symmetrical on both sides of the tire circumferential center of the pattern portion 100, 101. Each pattern portion 100, 101 includes multiple types of straight portions 103a, 103b, and 103c with different widths and multiple types of L-shaped portions 104a, 104b, and 104c with different widths. The straight portions 103a, 103b, and 103c are inclined relative to the tire circumferential direction. Each pattern portion 100, 101 also includes two types of V-shaped portions 105a, 105b, and 105c with different sizes and two types of recessed portions 106a and 106b that open radially outward. Multiple protrusions are formed on the inside of each shaped portion. Even within the same type of pattern region, the size of the protrusions arranged on the inside and the pitch, which is the distance between the apexes of the multiple protrusions, vary depending on the position, width, or size.

[0030] For example, as shown in FIGS. 3 and 4, three L-shaped portions 104a, 104b, and 104c of different widths have protrusions 30, 31, and 32 arranged at different unit sizes and pitches. While the following description focuses on the protrusions arranged on the L-shaped portions, the same applies to protrusions arranged on other shaped portions, such as linear portions. The L-shaped portion 104a, which has the smallest width, has a plurality of protrusions 30 with the smallest unit size among the three, and the pitch between the plurality of protrusions 30 is also the smallest. The L-shaped portion 104c, which has the largest width, has a plurality of protrusions 32 with the largest unit size among the three, and the pitch between the plurality of protrusions 32 is also the largest. The L-shaped portion 104b, which has a medium width, has a plurality of protrusions 31 with the intermediate unit size among the three, and the pitch between the plurality of protrusions 31 is intermediate between the maximum and minimum pitches.

[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 L-shaped portion 104b, 104c includes a recessed portion 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 linear direction inclined with respect to the tire circumferential direction, and the multiple protrusions 31, 32 arranged inside the recessed portion 109. The recessed portion 109 is recessed from the tire sidewall reference plane 14 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 tire side surface 13 facing outward in the tire axial direction of the sidewall 5 in a portion where no partial irregularities such as protrusions such as side blocks or recesses 109 are formed.

[0033] The plurality of 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 using Figs. 5 to 9, taking the protrusion 31 arranged in the L-shaped portion 104b having an intermediate width as a representative. Fig. 5 is a view of portion C in Fig. 4 as 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 as seen from a position closer to 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, as seen from the radially outer side of the tire. Fig. 8 is a cross-sectional view taken along line DD in Fig. 4. Fig. 9 is an enlarged view of portion E in Fig. 8.

[0035] FIG. 5 shows the recess 109 and the protrusion 31 inside the recess 109 in the inclined portion 107 that forms the L-shaped portion 104b. 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 six-sided polygonal shape, with two first faces 33, two second faces 34, and two third faces 35. Furthermore, 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 arrow J in FIG. 5, which is the tire circumferential direction, protrusions 31a having a partial shape of the protrusion 31 are aligned. The protrusions 31a have the shape of a portion of the protrusion 31, are cut by the wall surface 109a of the recess 109, and are connected to the wall surface 109a at the cut portion, forming a partial shape with six sides. The shape of the six-sided protrusions 31 will be described in detail below.

[0036] As shown in FIG. 5, each protrusion 31 has second surfaces 34, which are 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, each protrusion 31 has a shape in which a first surface 33 is connected to the tire radially outer side of each second surface 34 by a ridge line 36 that serves as an apex. More specifically, each protrusion 31 has 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 the ridge line 36 and are also connected to each other in a V-shape. Each protrusion 31 also has two identical triangular third surfaces 35 that are connected to both ends of the longitudinal direction along the V-shaped ridge line 36. Each protrusion 31 has a symmetrical shape on both sides with respect to the center in the second direction (the direction of the dashed dotted line K2 in FIG. 5 ). 5, when each protrusion 31 is viewed in a direction perpendicular to the bottom surface 110 of the recessed portion 109, the shape of each of the two second surfaces 34 is a rhombus. The bottom surface 110 has a shape that is 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 recessed portion 109 to the bottom surface 110 can be approximately the same overall. 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 the bottom surface 110 of the 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 the bottom surface 110. Also, each second surface 34 of each protrusion 31 is connected to the first surface 33 by a ridge line 36, and stands up so as to be inclined with respect to the bottom surface 110 at an angle β (FIG. 9) that is greater than 90 degrees + 15%.

[0038] 9 stands upright from the bottom surface 110 at the same angle α as the surface S1 that stands upright at 90 degrees relative to the bottom surface 110, but may also 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%, relative 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 strong contrast to the tire side surface 13. This allows the tire side surface 13 to have an excellent sense of shine by utilizing the reflection of light, resulting in a tire 1 with excellent design. Also, as will be described later, at multiple positions on the bottom surface 110 shown in FIG. 5, quadrangular areas such as diamonds can be formed in areas surrounded by four second surfaces 34. When the tire side surface 13 is viewed, these quadrangular areas have a brightness intermediate between the second surfaces 34 and shadow areas such as black lines.

[0040] The 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 top of the protrusion 31 can be made to protrude outward from the opening end 109b of the recess 109. For example, the portion including the top of the protrusion 31 can be made to protrude outward from the 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 a surface S1 that stands upright 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 formed with 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 create a contrast between light and dark on the tire side surface 13.

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

[0043] As in the embodiment, each first surface 33 of each protrusion 31 is erected from the bottom surface 110 at an angle within a range of ±15% based on the surface S1 that stands upright at 90 degrees to the bottom surface 110 of the recess 109, 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 ridge lines 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. The ridge lines 36 of the second surfaces 34 of the protrusion 31 on one side in the first direction (the lower side in FIG. 5) and the protrusion 31a adjacent to the protrusion 31 on the other side in the first direction (the upper side in FIG. 5) are aligned parallel to each other. In this case, the two adjacent protrusions 31, 31a 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, enhancing 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 diamond shape is formed on the bottom surface 110 in the area surrounded by the three protrusions 31, 31a, and a plurality of these diamond shapes are arranged in at least the first direction. This allows a regular pattern to be formed inside at least a portion of the pattern area including the inclined portions, in which diamond shapes formed by one second surface 34 of the protrusions 31 and diamond shapes on the bottom surface 110 are arranged alternately along the first direction. Note that, by widening the width of the inclined portions or reducing the size of each protrusion 31 in at least a portion of the pattern area including the inclined portions, it is also possible to arrange protrusions 31 having a shape with multiple six sides in each of the first and second directions that intersect with each other.

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

[0047] 10 is a diagram illustrating the shape of a portion of the pattern region of the tire side surface 13 in an embodiment, as viewed from the outside in a direction perpendicular to the bottom surface 110 of the recess. The pattern region is not limited to the L-shaped portion 104b. For ease of explanation, the protrusions in FIG. 10 will be described 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 the ridge lines 36 of the two second surfaces 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 portions 104b shown in FIGS. 4 and 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 portions 104a shown in FIGS. 3 and 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 portions 104c shown in FIGS. 4 and 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 the first pattern region, the second pattern region, and the 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] As with the L-shaped portion, the recessed portions 106a and 106b shown in FIG. 2B also have two types of pattern regions with different widths, each with a different pitch P of the multiple protrusions. However, the pitch P of the multiple protrusions may also be the same in multiple types of pattern regions with different widths. For example, the three types of straight line portions 103a, 103b, and 103c shown in FIGS. 2B and 3 have different widths, but their respective pitches P are the same as the pitch P1 of the L-shaped portion 104a. In FIG. 2B, the pattern region with the minimum pitch P1 is indicated by PA1, the pattern region with the maximum pitch P3 is indicated by PA3, and the pattern region with the intermediate pitch P2 is indicated by PA2. Because the pitch P of the multiple protrusions is different in the multiple types of pattern regions, different brightness can be achieved at multiple positions on the tire side surface 13 due to differences in the spacing of the second surface, which serves as a reflective surface, as shown in FIG. 3. As the pitch P increases, the area of ​​the second surface corresponding to the pitch P can be increased when the gap between adjacent protrusions is kept as small as 0.1 mm, making it easier to make the second surface shine. Conversely, as the pitch P decreases, 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 and Lc of the diamond shape of each second surface 34 when 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. If Lb and Lc are less than 0.8, the highlighted portion is significantly reduced. On the other hand, if Lb and Lc are more than 1.2, the highlighted portion is significantly increased compared to the bottom surface 110, which has a lower brightness than the second surface 34, making it difficult to create a difference in brightness on the tire side surface 13. Note that Lb and Lc may be different from each other.

[0051] 10, when the pitch P is 1, the lateral 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 preferably 0.5 or more and 0.7 or less. If Ld is less than 0.5, the area of ​​the diamond-shaped portion with low lightness is significantly reduced. On the other hand, if Ld exceeds 0.7, the area of ​​the diamond-shaped portion with low lightness becomes too large compared to the highlight portion, reducing the effect of the highlight portion on the tire side surface 13.

[0052] Returning to FIG. 8 , for the multiple protrusions 31, the protrusion pitch ratio P / H, which is the ratio of the pitch P of adjacent protrusions 31 to 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 reduces the width of the wake region formed on the downstream side of the airflow of the tire 1, where the airflow speed is reduced, thereby suppressing an increase in the air resistance of the tire 1. Furthermore, by setting the protrusion pitch ratio P / H to 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.

[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 the bottom surface 110, turbulence causes the airflow to reattach to another protrusion 31 downstream, and the separation point is likely to shift downstream. In this embodiment, the protrusion pitch ratio P / H is 2 or greater and 6 or less, so that the airflow that collides with the protrusion 31 on the bottom surface 110 becomes turbulent and heads downstream, and this turbulent flow again collides with another protrusion 31 downstream, and this process is repeated. This makes it easier for the separation point of the airflow on the tire side surface 13 to shift downstream. Therefore, as described below, the width of the wake region, which is formed by the portion sandwiched on both sides by the separated airflow from the separation position on the tire side surface 13 and experiences negative pressure, can be reduced on the downstream side of the airflow of the tire. This reduces the pressure resistance caused by the formation of the protrusions 31, thereby suppressing an increase in air resistance.

[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 arrow U2, making it difficult for turbulence to occur in the airflow. As a result, the separation point of the airflow on the tire side surface 13 is less likely to shift downstream. Therefore, the effect of reducing negative pressure is reduced, and the effect of suppressing an increase in air resistance is also 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 negative pressure reduction effect is reduced. In this case, the effect of suppressing an increase in air resistance also 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 using Figures 13 and 14. Figure 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 a tire side surface 13 in the air flow in another example configuration in which the protrusion pitch ratio is less than 2. In Figure 13, many turbulent flows are formed inside the wake region 40. In Figures 13 and 14, the tire is shown simulated by the cylinder Sa.

[0057] In another example shown in FIG. 13 , the protrusion pitch ratio is less than 2, so that the tire side surface 13, like a smooth surface, does not generate turbulence as described above. In this case, consider the case where an airflow, indicated by a broken line, collides with the surface of the cylinder Sa, which serves as the tire side surface 13, as the tire rotates during vehicle travel. In this case, a positive pressure is generated on the airflow upstream side of the cylinder Sa, pushing the cylinder Sa downstream. Then, as the airflow flows downstream along the surface of the cylinder Sa from the airflow upstream side of the cylinder Sa, it separates from the surface of the cylinder Sa at positions C1 and C2 in FIG. 13 . Then, a wake region 40, where negative pressure exists, is formed in the area sandwiched between the separated airflows 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 negative pressure reduction effect is small. Therefore, when the protrusion pitch ratio is less than 2, the effect of suppressing an increase in pressure resistance in the tire is low, and therefore the effect of suppressing an increase in air resistance is also small.

[0058] 14 is a schematic diagram illustrating, in an embodiment, a cylinder S simulating that the width of a wake region 40 caused by a separated air flow narrows downstream of the air flow from the tire side surface 13, thereby enhancing the negative pressure reduction effect. 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, the protrusion pitch ratio is 2 or more and 14 or less. Therefore, for the reasons explained in FIG. 11 , the separation point of the airflow from the tire side surface 13 is likely to shift to downstream positions C3 and C4. This makes it possible to reduce the width of a wake region 40 that is formed on the downstream side of the cylindrical body S simulating a tire, in a portion sandwiched on both sides by the separated airflow from the separation point on the surface of the cylindrical body S and that experiences negative pressure. FIG. 14 simulates the formation of multiple protrusions 31 on the tire side surface 13 on both axial sides of the tire. However, even in the case where multiple protrusions 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 an increase in pressure resistance in the tire is enhanced, thereby suppressing an increase in air resistance.

[0060] Furthermore, the multiple protrusions may be configured to be formed on the tire side surface 13 within a range in the tire radial direction Y (the range indicated by the arrow η in FIG. 1 ) of 25% or more and 65% or less when the tire radial 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 a range from the vicinity of the outer end in the tire axial direction (P in Figure 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 where the protrusions are easily noticeable and have a great effect on improving the design.

[0062] Fig. 15 is a cross-sectional view showing a tire molding mold of an embodiment. Fig. 16 is a perspective view showing a portion of a portion of the tire molding mold in an embodiment where recesses 80 corresponding to a plurality of protrusions are formed. The pneumatic tire of this embodiment is formed using a tire molding mold 70. Hereinafter, the tire molding mold 70 will be referred to as mold 70. Mold 70 is a mold used to mold the tire 1 shown in Figs. 1 to 10 above. Mold 70 can impart an excellent shine to the tire side surface 13 by utilizing light reflection, thereby realizing a tire with excellent design.

[0063] Hereinafter, each member will be described in accordance with the tire axial direction X and tire radial direction Y of the tire 1 molded 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 protrusions 75 are portions that form circumferential grooves in the tire 1. The protrusions 75 are made of the same material as the metal material that makes up the main body 74.

[0067] The side mold 72 has a main body 76 with side molding surfaces 77a, 77b, and the side molding surface 77a, which forms the tire side surface on the outer side of the vehicle, has a plurality of protrusions 78 that protrude 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 parts that form a plurality of recesses 109 in the tire 1, with the plurality of protrusions rising from a bottom surface 110.

[0068] The tread mold 71 has a fan shape in a plan view, formed by dividing an annular body into multiple parts in the circumferential direction. The multiple divided tread molds 71 ​​form a continuous annular body with an inner diameter corresponding to the outer diameter of the tire 1 to be molded when in a clamped state, as described below. The upper side mold 72 is annular and fixed to the lower surface of an upper plate (not shown) constituting the vulcanization molding machine, and moves up and down as a first lifting member (not shown) moves up and down. The lower side mold 72 is annular and fixed to the floor surface and to the lower surface of a lower plate (not shown) constituting the vulcanization molding machine. The vulcanization molding machine raises and lowers multiple segments (not shown), one for each tread mold 71, outside the multiple divided tread molds 71, using a first lifting member. Simultaneously with the raising and lowering of the first lifting member, the vulcanization molding machine slides the inclined surfaces of the outer peripheral surfaces of the multiple segments up and down on an inclined cylindrical surface provided at the lower end of a second lifting member (not shown) that moves up and down 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 configured in this manner, a green tire is placed on the lower tread mold 71 with the tire axial direction aligned vertically when the mold is open. An inflatable bladder is then placed inside the green tire, and air is supplied to the bladder to inflate it. Then, with the inner surface of the green tire held by the outer surface of the bladder, 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 side molding surfaces 77a, 77b by the pressure from the mold 70, and a heat exchange medium adjusted to a predetermined temperature is constantly flowing between the member fixing the upper plate and the member fixing the lower plate. This vulcanizes the rubber of the green tire, completing a tire 1 with a predetermined shape.

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

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

[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, NC machining using a cutting tool such as an end mill, laser machining, or electric discharge machining can be used for the drilling.

[0073] FIG. 17 is a cross-sectional view showing multiple 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 multiple protrusions 31 protruding from the bottom surface 110 of the recessed portion 109 and multiple protrusions 31c protruding from the sidewall reference surface 14 outside the recessed portion 109. The shapes of the multiple protrusions 31, 31c are similar to the protrusions 31 formed in the tire 1 shown in FIGS. 1 to 10. In this example, light reflection by the reflective surface of the protrusions 31c on the sidewall reference surface 14 becomes more noticeable. This makes it easier to add 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 recessed portion 109. Therefore, in terms of suppressing an increase in air resistance, it is preferable to have the protrusions 31 protrude from the bottom surface 110 of the recessed portion 109, as in the configuration shown in FIGS. 1 to 10. 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 diagram corresponding to FIG. 2B of a tire according to another embodiment. In this example, an annular portion 112 including two pattern-forming portions 111 is provided on the tire side surface 13. 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 in the tire circumferential direction. Each pattern-forming portion 111 has multiple pattern regions 113, 114, 115, 116, 117, and 118 based on curves and including multiple spiral portions. Each of the multiple pattern regions has multiple curved portions with different widths. The multiple curved portions have multiple recesses along the longitudinal direction of the curves, and multiple protrusions are formed so as to rise from the bottom surface of each recess 9. The shape of each protrusion formed in the curved portion is similar to the protrusions 31 formed on the tire 1 shown in FIGS. 1 to 10. The multiple protrusions may not be arranged in a linear direction but may be dispersed in the curved direction. 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 the same as those in Figures 1 to 10, 15, and 16.

[0075] Although not shown in the drawings, 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 relative to the tire circumferential direction. In this case, without changing the size of the protrusions or the pitch of the multiple protrusions, different brightness can be achieved at multiple positions on the tire side surface by changing the orientation of the second surface, which serves as the reflective surface. 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 the tire mounting direction may be unspecified by forming protrusions on the tire side surfaces on both sides of the vehicle.

[0077] Furthermore, the protrusion arrangement region may be formed over the entire tire circumferential surface, or the protrusion arrangement region may be formed in three or more separate positions in the tire circumferential direction. Furthermore, multiple protrusions may be formed in a row in the tire circumferential direction or in a direction inclined at a predetermined angle relative to the tire circumferential direction. This facilitates reducing air resistance on the tire side surface. Meanwhile, randomly arranging multiple protrusions on the tire side surface facilitates reducing air resistance in response to various changes in the direction of tire travel, the direction of tire rotation, and the wind flow in the direction of wind around the contact patch.

[0078] Furthermore, in the above embodiment, the protrusion provided on the tire side surface has a polygonal shape with six sides including two first sides and two second sides, but the protrusion may have a polygonal shape with at least one first side and one second side. For example, the protrusion may have only one first side standing upright from the tire side surface at an angle within a range of ±15% based on a surface that stands upright at 90 degrees to the tire side surface, and only one second side connected to the first side at its apex and inclined at an angle greater than 90 degrees + 15% to the tire side surface, and may have a polygonal shape with 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 contact edge of the tread and on the tire radially outer side of the rim line, Each of the plurality of 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 upright at 90 degrees to the tire side surface, and a second surface that is connected to the first surface at its apex and rises so as to be inclined at an angle greater than 90 degrees + 15% to the tire side surface. Configuration 2: Each of the plurality of protrusions has a polygonal shape including 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. 10. The pneumatic tire according to claim 1. Configuration 3: A projection having a first pattern area and a second pattern area, wherein a pitch that is a distance between vertexes of the plurality of protrusions arranged in the first pattern area is different from a pitch that is a distance between vertexes of the plurality of protrusions arranged in the second pattern area. 3. The pneumatic tire according to claim 1 or 2. Configuration 4: The plurality of protrusions of the same shape 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 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: P / H, which is the ratio of the pitch P, which is the distance between the apexes of adjacent protrusions, to the height H of the protrusions, 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. The 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 mold 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 line, 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, located radially inward of the ground contact edge of the tread and radially outward of the rim line, a first surface extending from the tire side surface at an angle within a range of ±15% with respect to a surface that is perpendicular to the tire side surface at 90 degrees relative to the tire side surface; and a 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% relative to the tire side surface.

2. each of the plurality of protrusions has a polygonal shape including 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. The pneumatic tire according to claim 1 .

3. The projections have a first pattern area and a second pattern area, and a pitch that is a distance between vertexes of the plurality of projections arranged in the first pattern area is different from a pitch that is a distance between vertexes of the plurality of projections arranged in the second pattern area. The pneumatic tire according to claim 1 .

4. the plurality of protrusions of the same shape 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 .

5. the plurality of protrusions are formed on the tire side surface so as to protrude from a bottom surface of a recessed portion recessed from a sidewall reference plane toward the tire inner surface, The pneumatic tire according to claim 1 .

6. a ratio P / H of a pitch P, which is the 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 .

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

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

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 claim 1 .

10. the protrusion is formed on the tire side surface within a range in the tire radial direction of 25% to 65% when the tire radial direction 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 .

11. A pneumatic tire mold for molding the pneumatic tire according to any one of claims 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.

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