Pneumatic tire and mold for molding pneumatic tire

Abstract

To provide a pneumatic tire that can improve steering stability on a dry road surface at the time of turning a vehicle and improve braking performance on a wet road surface and abrasion resistance, while suppressing internal heat generation from increasing and reducing air resistance.SOLUTION: A pneumatic tire 1 includes an inner wavy curved surface 30 formed on a tire side surface inside of a vehicle, of a pair of tire side surfaces and an outer wavy curved surface formed on a tire side surface outside of the vehicle. The wavy curved surfaces respectively are made wavy in a tire radial direction and in a tire circumferential direction so that the surfaces have a plurality of mountain-shape protrusions, in the tire radial direction and in the tire circumferential direction, on the corresponding tire side surfaces. Bottom edges of the plurality of inner mountain-shape protrusions 35 of the inner wavy curved surface constituting the plurality of mountain-shape protrusions do not overlap each other, in the tire circumferential direction, on inner mountain-shape protrusion rows 51 adjacently arranged in the tire radial direction. Bottom edges of the plurality of outer mountain-shape protrusions of the outer wavy curved surface overlap each other, in the tire circumferential direction, on outer mountain-shape protrusion rows adjacently arranged in the tire radial direction.SELECTED DRAWING: Figure 5

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 an undulating curved surface provided 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, changes to the shape of tire sidewalls have been considered to improve the design of tires. For example, Patent Document 1 describes the provision of multiple cylindrical protrusions that protrude from the surface of the sidewall and generate turbulence. Patent Document 1 states that turbulence is generated by the edges of the connecting portions between the tip surfaces of the protrusions and the sidewall surface.

[0003] Patent Document 2 describes that a plurality of protrusions that protrude outward from the tire are regularly arranged on the surface of the tire side, 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, which is said to form an optimal air relaxation layer on the tire surface.

[0004] Patent Document 3 describes a configuration in which a tire sidewall is formed with a plurality of mountain-shaped protrusions with varying heights and minute pitches, resulting in an overall undulating shape that is inclined relative to the tire circumferential direction, which is said to improve the rigidity of the sidewall. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2008 / 096879 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-169827 [Patent Document 3] Chinese Patent Application Publication No. 107499068 Summary of the Invention [Problem to be solved by the invention]

[0006] The configurations described in Patent Documents 1 to 3 leave room for improvement in terms of suppressing an increase in internal heat generation in pneumatic tires, reducing air resistance, and improving handling stability when a vehicle turns on dry roads and braking performance and wear resistance on wet roads. [Means for solving the problem]

[0007] A pneumatic tire according to the present invention includes a pair of tire side surfaces that are axially outer surfaces of the tire radially inward of ground contact edges at both axial ends of the tread and radially outward of the rim line, and includes an inner undulating curved surface provided on the tire side surface on the vehicle inner side, and an outer undulating curved surface provided on the tire side surface on the vehicle outer side, and the inner undulating curved surface and the outer undulating curved surface are curved surfaces that undulate in the tire radial direction and the tire circumferential direction so as to have a plurality of chevron-shaped protrusions on the tire side surface on the corresponding side in the tire radial direction and the tire circumferential direction, and the inner undulating curved surface includes a plurality of inner chevron-shaped protrusion rows lined up in the tire radial direction, and the plurality of inner undulating curved surfaces are curved surfaces that undulate in the tire radial direction and the tire circumferential direction so as to have a plurality of chevron-shaped protrusion rows on the tire radial direction and the tire circumferential direction. Each of the angle-shaped projection rows has a plurality of inner angle-shaped projections that constitute the plurality of angle-shaped projections and are lined up in the tire circumferential direction, the bottom edges of the plurality of inner angle-shaped projections in the plurality of inner angle-shaped projection rows do not overlap in the tire circumferential direction between adjacent inner angle-shaped projection rows in the tire radial direction, the outer undulating surface includes a plurality of outer angle-shaped projection rows that are lined up in the tire radial direction, each of the plurality of outer angle-shaped projection rows has a plurality of outer angle-shaped projections that constitute the plurality of angle-shaped projections and are lined up in the tire circumferential direction, and the pneumatic tire is such that the bottom edges of the plurality of outer angle-shaped projections in the plurality of outer angle-shaped projection rows that are adjacent in the tire radial direction overlap in the tire circumferential direction.

[0008] The pneumatic tire molding mold according to the present invention is a pneumatic tire molding mold for molding the pneumatic tire according to the present invention, and has a mold-side curved surface on the molding surface that corresponds to the undulating curved surface, and a plurality of curved surface inner recesses that correspond to the curved surface protrusions are formed on the mold-side curved surface. [Effects of the Invention]

[0009] With the pneumatic tire and pneumatic tire mold of the present invention, the surface area of ​​the pneumatic tire can be increased, thereby suppressing an increase in internal heat generation, and the edgeless curved shape suppresses the generation of turbulence, thereby reducing air resistance, and improving handling stability when the vehicle turns on dry roads, while also improving braking performance and wear resistance on wet roads. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram showing a tire contour shape in a meridian cross section of a vehicle inner half portion of a pneumatic tire that is an example of an embodiment, and is a diagram showing a range in which an inner undulating surface is formed. FIG. [Figure 2] 1 is a perspective view showing a part in the tire circumferential direction of a vehicle-inner end portion of a pneumatic tire according to an embodiment, cut away from other portions. [Figure 3] FIG. 2 is a perspective view showing a partially cutaway annular portion that forms an inner undulating curved surface in the embodiment. [Figure 4] FIG. 2 is an enlarged cross-sectional view of part A in FIG. [Figure 5] 1 is a schematic diagram showing the arrangement positions of a plurality of inner angled protrusions on a portion of the inner wavy surface of a pneumatic tire according to an embodiment in the circumferential direction of the tire. FIG. [Figure 6] FIG. 2 is a diagram showing a tire contour shape in a meridian cross section of a vehicle outer half portion of a pneumatic tire according to an embodiment, and is a diagram showing the range in which an outer undulating surface is formed. [Figure 7] 1 is a schematic diagram showing the arrangement positions of a plurality of outer angled protrusions on a portion of the tire circumferential direction on an outer undulating surface of a pneumatic tire according to an embodiment. FIG. [Figure 8]FIG. 2 is a cross-sectional view showing a mold for molding a pneumatic tire in an embodiment. [Figure 9] 10 is a schematic diagram showing the arrangement positions of a plurality of inner angled protrusions on a portion of the tire circumferential direction on an inner wavy curved surface of a pneumatic tire according to another example of the embodiment. FIG. [Figure 10] 10 is a schematic diagram showing the arrangement positions of a plurality of outer angled protrusions on a portion of the tire circumferential direction on an outer undulating surface of a pneumatic tire according to another example of the embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] FIG. 1 is a diagram showing the tire contour shape in a meridian cross section of the vehicle-inner half of a pneumatic tire 1 according to an embodiment, and is a diagram showing the range in which the inner undulation surface 30 is formed. FIG. 2 is a perspective view showing a circumferential portion of the vehicle-inner end of the pneumatic tire 1, cut away from the rest of the tire. FIG. 3 is a perspective view showing a partially cutaway annular portion 100, where the inner undulation surface 30 is formed, in an embodiment. FIG. 4 is an enlarged cross-sectional view of portion A in FIG. 1. FIG. 5 is a schematic diagram showing the positions of multiple inner angled protrusions 35 on a portion in the tire circumferential direction of the inner undulation surface 30 of the pneumatic tire 1. FIG. 6 is a diagram showing the tire contour shape in a meridian cross section of the vehicle-outer half of the pneumatic tire 1, and is a diagram showing the range in which the outer undulation surface 40 is formed. FIG. 7 is a schematic diagram showing the positions of multiple outer angled protrusions 45 on a portion in the tire circumferential direction of the outer undulation surface of the pneumatic tire 1.

[0013] As shown in Figures 1, 2, and 6, a pneumatic tire 1 has a tread 10, which is a 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 a plurality of blocks, and is formed in an annular shape along the tire circumferential direction. In Figures 1 and 6, the tread 10 is shown as being formed of a single block, but in reality, as shown in Figure 2, the tread 10 includes a plurality of blocks 11a, 11b separated in the tire axial direction X. The plurality of blocks 11a, 11b are separated by a circumferential groove 11c (Figure 2) extending in the tire circumferential direction. The tread 10 has ground-contact edges T1, T2 (Figures 1 and 6). In Figures 1, 2, and 6, the tire axial direction is indicated by X, the tire radial direction is indicated by Y, and the tire circumferential direction is indicated by α.

[0014] Hereinafter, the configuration of the tire 1 will be described by dividing it into a portion on the vehicle inner side (IN side) and a portion on the vehicle outer side (OUT side) with respect to the center CL in the tire axial direction X. The mounting direction of the front and back sides of the tire 1 on the vehicle is specified. That is, the tire 1 is specified to have two sides that are to be the inner side and the outer side in the vehicle width direction. In Figs. 1 and 6, the tire 1 is mounted on the vehicle so that the right side is the inner side in the vehicle width direction (IN side) and the left side is the outer side in the vehicle width direction (OUT side).

[0015] 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 identified by providing a serial number only on the tire side surface 13a facing the outside of the vehicle, or by providing different serial numbers on the tire side surface 13a facing the inside of the vehicle and the tire side surface 13b facing the outside of the vehicle (FIG. 6). 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 in the vehicle width direction.

[0016] Furthermore, a marking such as a letter or symbol may be provided on the tire side surface 13a facing the outside of the vehicle to indicate that the tire is on the outside when mounted on the vehicle.

[0017] The tire 1 includes sidewalls 12a, 12b that are provided at the outer ends of the tread 10 in the tire axial direction X and bulge outward most in the tire axial direction X, and beads 15 ( FIG. 2 ) that are fixed to the rim of a wheel. The sidewalls 12a, 12b and the beads 15 are formed in an annular shape along the tire circumferential direction. The sidewalls 12a, 12b extend 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 15 is provided adjacent to the sidewalls 12a, 12b at the inner ends of the tire 1 in the radial direction Y.

[0018] The tire 1 is a pneumatic tire filled with air at a predetermined pressure. The tread 10 is made of tread rubber. The sidewalls 12a, 12b are made of a different type of sidewall rubber than the tread rubber.

[0019] 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 the standard internal pressure, and in a standard, unloaded state.

[0020] "Track edges T1, T2" refer 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.

[0021] 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.

[0022] 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 framework of the tire 1 that can withstand loads, impacts, air pressure, etc. The belt layer is a reinforcing band placed between the tread rubber 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 made of steel or the like.

[0023] 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.

[0024] 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 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 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 Figures 1 and 6, a configuration without the rim protector 19 is also possible, as indicated by the two-dot chain line in Figures 1 and 6. 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.

[0025] In this example, of a pair of tire side surfaces 13a, 13b that are axially outer surfaces of the tire located radially inward of ground contact edges T1, T2 at both axial ends of the tread 10 and radially outward of the rim line 20, the tire side surface 13a on the vehicle inner side is provided with an annular portion 100 including an inner undulating curved surface 30. Of the pair of tire side surfaces 13a, 13b, the tire side surface 13b on the vehicle outer side is provided with an annular portion 200 including an outer undulating curved surface 40. The inner undulating curved surface 30 and the outer undulating curved surface 40 are curved surfaces that undulate radially and circumferentially so that the corresponding tire side surfaces 13a, 13b have multiple angle-shaped protrusions 35, 45 in the tire radial and circumferential directions.

[0026] First, the annular portion 100 including the inner undulating curved surface 30 provided on the tire side surface 13a on the vehicle inner side will be described with reference to FIGS.

[0027] As shown in FIG. 2 , an annular portion 100 having a constant length in the tire radial direction is provided on the tire side surface 13a facing the vehicle interior side. The annular portion 100 is formed by an inner undulating surface 30 protruding axially outward from the bottom of an annular recess 37. Hereinafter, the inner undulating surface 30 will be referred to as an undulating surface 30. The undulating surface 30 undulates in the tire radial and circumferential directions so as to have a plurality of inner angled protrusions 35 constituting a plurality of angled protrusions 35, 45 in the tire radial and circumferential directions. The apexes 31 of the inner angled protrusions 35 that protrude furthest outward from the tire and the plurality of valley points 38 that are recessed furthest toward the tire interior are each provided at the same pitch throughout the tire circumferential direction and at the same pitch in the tire radial direction. As will be described later, the tire of the present invention may be configured to include, instead of the annular portion 100 having the annular recessed portion 37 on the inside of which an annular undulating surface is formed, an arc-shaped portion provided at one or more positions around the tire circumferential direction of the tire side surface 13a and having an arc-shaped recessed portion on which an arc-shaped undulating surface is formed in the tire circumferential direction,

[0028] The undulating surface 30 is formed inside an annular recess 37 provided along the tire circumferential direction on the tire side surface 13a on the vehicle inner side. The annular recess 37 is recessed from the sidewall reference surface 14a toward the tire inner surface with the same radial width in the tire.

[0029] The sidewall reference surface 14a refers to the surface of the tire side surface 13a facing outward in the axial direction of the sidewall 12a in a portion where partial irregularities such as protrusions of side blocks or recesses are not formed.

[0030] The undulating surface 30 is formed to protrude in the tire axial direction inside the annular recess 37 so that valleys and peaks are alternately repeated in the tire circumferential direction and the tire radial direction, with valley points 38 at multiple positions in the tire radial direction on the bottom surface of the annular recess 37 in the tire circumferential direction. As a result, the undulating surface 30 is formed to rise in the tire axial direction from the bottom surface of the annular recess 37. Therefore, the undulating surface 30 changes periodically in the tire circumferential direction and the tire radial direction.

[0031] In this example, as shown in the schematic diagram of FIG. 5 , the undulating surface 30 includes multiple inner angle-shaped projection rows 51 aligned in the tire radial direction. FIG. 5 corresponds to a view of a portion of the undulating surface 30 in the tire circumferential direction as viewed from the tire axially outer side, with the insides of the multiple circles indicating the bottom edges of the inner angle-shaped projections 35 of the inner angle-shaped projection rows 51, and the centers of the multiple X-shapes on the inside of the circles indicating the vertices 31 of the inner angle-shaped projections 35. As shown in FIG. 5 , each inner angle-shaped projection row 51 has multiple inner angle-shaped projections 35 aligned in the tire circumferential direction, and the bottom edges of the multiple inner angle-shaped projections 35 in the multiple inner angle-shaped projection rows 51 adjacent in the tire radial direction do not overlap in the tire circumferential direction. As a result, an annular region 54 is formed between the inner angle-shaped projection rows 51 adjacent in the tire radial direction, which is a region along the tire circumferential direction indicated by the hatched area in FIG. 5 and where no inner angle-shaped projections 35 exist. Therefore, as will be described later, wet braking performance, which is braking performance on wet roads, and wear resistance can be improved.

[0032] Furthermore, in the undulating surface 30 of this example, the opposite circumferential ends of the multiple inner angled projections 35 of the inner angled projection rows 51 adjacent to each other in the tire radial direction do not overlap in the tire radial direction.

[0033] At positions overlapping the annular regions 54 and between the multiple inner angle-shaped-projection rows 51, there are undulating portions 52 that undulate in the tire circumferential direction. Valley points 38 are located at multiple positions in the tire circumferential direction of the undulating portions 52. In FIG. 5, the valley points 38 are indicated by the centers of crosses. However, the amount of undulation in the height direction of the undulating portions 52 is smaller than the amount of undulation in the height direction of the inner angle-shaped-projection row 51. The apex 31 of the inner angle-shaped projection 35 is located axially outermost on the undulating surface 30, and the valley point 38 is located axially innermost on the undulating surface 30, on the tire inner surface side.

[0034] The phases of the apexes 31 of the multiple inner angle-shaped projection rows 51 match among the multiple inner angle-shaped projection rows 51. The phases of the valley points 38 of the undulation portion 52 are located between the apexes 31 of the inner angle-shaped projection rows 51 in the tire circumferential direction.

[0035] In FIG. 5, a plurality of broken lines extending in the tire circumferential direction indicate either the inner angled projection row 51 or the undulation portion 52.

[0036] Furthermore, in this example, when the tire circumferential pitch of the undulation surface 30 is Pr (FIG. 3) and the tire radial pitch of the undulation surface 30 is Pd (FIG. 3), it is preferable that Pd>Pr and Pr / Pd is equal to or greater than 0.2 and less than 1. According to this configuration, the tire circumferential pitch Pr is small, so that the rubber of the tire side surface 13a can improve the tire radial rigidity at many positions in the tire circumferential direction while ensuring ease of slippage in the tire circumferential direction at multiple positions in the tire radial direction, making it easier to achieve both improved wet braking performance and improved handling stability.

[0037] Both ends of the undulating surface 30 in the tire radial direction are connected to the wall surfaces of both ends of the annular recess 37 in the tire radial direction. A height H1 (FIG. 4) from a valley point 38 of the undulating surface 30 to an apex 31 of the angled protrusion 35 is slightly larger than a depth D1 (FIG. 4) from an opening end 39 of the annular recess 37 to the valley point 38 on the bottom surface. As a result, the vicinity of the apex 31 of each inner angled protrusion 35 protrudes outward beyond the opening end 39 of the annular recess 37.

[0038] 4, the height H1 of the undulating surface 30 is, for example, 0.3 mm or more and 1.1 mm or less. Meanwhile, the depth D1 of the annular recess 37 is 0.2 mm or more and 1.0 mm or less, and it is preferable that the vicinity of the apex 31 of the inner angled protrusion 35 protrudes outward from the opening edge 39 of the annular recess 37 by 0.1 mm or more. By having the vicinity of the apex 31 of the inner angled protrusion 35 protrude outward from the opening edge 39 of the annular recess 37 in this manner, the presence of the undulating surface 30 can be emphasized from the outside, thereby improving the design of the tire side surface 13a.

[0039] 3, the tire circumferential pitch Pr of the undulating surface 30, which is the distance between vertices 31 of the inner angle-shaped protrusions 35 in the tire circumferential direction, is 3 mm or more and 80 mm or less. Preferably, the tire circumferential pitch Pr is 20 mm or more and 30 mm or less.

[0040] Furthermore, when the circumferential pitch of the undulation surface 30 is Pr and the height of the undulation surface 30 is H1, the radius of curvature of the curved surfaces of the peaks and valleys of the undulation surface 30 in the circumferential direction of the tire is equal to or greater than (Pr / 2) and equal to or less than ((Pr / H1)+Pr). The radius of curvature of the curved surfaces of the peaks and valleys in the circumferential direction of the tire may be the same or different. For example, the radius of curvature of the curved surfaces of the peaks in the circumferential direction of the tire may be greater than the radius of curvature of the curved surfaces of the valleys. In this case, a wider area of ​​the tire side surface 13a can receive input from the road surface to the tire, thereby increasing rigidity.

[0041] Furthermore, since the undulating surface 30 is formed so as to rise from the bottom surface of the annular recess 37 in the tire axial direction as described above, it becomes easier to equalize the volume of the tire rubber, it becomes easier to form the undulating surface 30, and the weight of the entire tire can be reduced.

[0042] As described above, on the tire side surface 13a on the vehicle inner side of the tire 1, referring to the schematic diagram of Figure 5, the undulating surface 30 undulates in the tire radial direction and the tire circumferential direction so as to have a plurality of inner angled protrusions 35 in the tire radial direction and the tire circumferential direction. Furthermore, the undulating surface 30 includes a plurality of inner angled protrusion rows 51 aligned in the tire radial direction. Each inner angled protrusion row 51 has a plurality of inner angled protrusions 35 aligned in the tire circumferential direction, and the bottom edges of the plurality of inner angled protrusions 35 in the plurality of inner angled protrusion rows 51 do not overlap in the tire circumferential direction between inner angled protrusion rows 51 adjacent in the tire radial direction.

[0043] This increases the surface area of ​​the tire 1, thereby suppressing an increase in internal heat generation, and the edgeless curved shape suppresses the generation of turbulence, thereby reducing air resistance. Furthermore, the wet braking performance and wear resistance of the tire 1, which is its braking performance on wet roads, can be improved. Specifically, the undulating curved surface 30 allows the multiple inner chevron-shaped protrusions 35 of the multiple inner chevron-shaped protrusion rows 51 to be aligned at a position close to the tire circumferential direction. Therefore, due to the undulations in the tire radial direction, the rubber on the tire side surface 13a is more likely to move in the shear direction in the tire's fore-and-aft direction during wet braking, with the rubber partially shifting in an appropriate manner, causing it to move in the direction of travel with an appropriate partial shift. This improves wet braking performance and wear resistance.

[0044] In addition, since tires are generally mounted on a vehicle with a negative camber, when the vehicle is traveling straight, the tire tilts downward toward the outside of the vehicle, making the contact pressure of the tread at the tire's inner edge more likely to be higher than that of the tread at the tire's outer edge. At this time, the undulating surface 30 can increase the tire's contact area. More specifically, at the tire's radially outer edge of the undulating surface 30, multiple inner chevron-shaped protrusions 35 are closely spaced in the tire circumferential direction, making it easier for the rubber near the tire side surface 13a at the bottom of the tire 1 to flexibly deform vertically in response to changes in the road surface. This tends to increase the contact area of ​​the tread at the tire's inner edge. This further improves wet braking performance and wear resistance. Furthermore, the circumferential undulation of the undulating surface 30 allows the rubber of the tire side surface 13a to adequately absorb vertical movement, thereby maintaining steering stability.

[0045] Next, the annular portion 200 including the outer undulating curved surface 40 provided on the tire side surface 13b on the vehicle outer side will be described with reference to FIGS.

[0046] As shown in FIG. 6 , an annular portion 200 having a constant length in the tire radial direction is provided on the tire side surface 13b facing the vehicle outboard side. Similar to the annular portion 100 shown in FIGS. 2 and 4 , the annular portion 200 is formed by an outer undulating surface 40 protruding axially outward from the bottom of an annular recess. Hereinafter, the outer undulating surface 40 will be referred to as the undulating surface 40. Similar to the undulating surface 30, the undulating surface 40 undulates in the tire radial and circumferential directions to have a plurality of outer angled protrusions 45 constituting a plurality of angled protrusions 35, 45 in the tire radial and circumferential directions. The peaks 41 of the angled protrusions 45 that protrude furthest outward from the tire and the valley points 48 that are recessed furthest toward the tire inboard side are arranged at the same pitch throughout the tire circumferential direction and at the same pitch in the tire radial direction. As will be described later, the tire of the present invention may be configured to include, instead of the annular portion 200 having an annular recessed portion on the inside of which an annular undulating surface is formed, an arc-shaped portion provided at one or more positions in the circumferential direction of the tire on the tire side surface 13b, and having an arc-shaped recessed portion on which an arc-shaped undulating surface is formed in the circumferential direction of the tire.

[0047] 7, the undulating surface 40 is formed inside an annular recess provided along the tire circumferential direction on the tire side surface 13b on the vehicle outer side. The annular recess is recessed from the sidewall reference surface 14b toward the tire inner surface with the same radial width.

[0048] The sidewall reference surface 14b refers to the surface of the tire side surface 13b facing outward in the tire axial direction of the sidewall 12b in a portion where partial irregularities such as protrusions of side blocks or recesses are not formed.

[0049] The undulating surface 40 includes multiple outer angle-shaped protrusion rows 61a, 61b aligned in the tire radial direction. Each outer angle-shaped protrusion row 61a, 61b has multiple outer angle-shaped protrusions 45 aligned in the tire circumferential direction. Furthermore, unlike the undulating surface 30 shown in FIG. 5 , the undulating surface 40 has the vertices 41 of the multiple outer angle-shaped protrusion rows 61a, 61b undulating in the tire circumferential direction shifted in phase by half a pitch between two adjacent outer angle-shaped protrusion rows 61a, 61b in the tire radial direction. Furthermore, between the adjacent outer angle-shaped protrusion rows 61a, 61b in the tire radial direction, a undulating portion 62 extends in the tire circumferential direction while changing in a wavy shape on both sides in the tire radial direction. The undulating portion 62 changes in a wavy shape in the height direction and in both the tire radial and circumferential directions. Valley points 48 are located at multiple positions in the undulating portion 62 in the tire circumferential direction. The dashed lines, circles, X-shapes, and crosses in FIG. 7 have the same meanings as in FIG.

[0050] Furthermore, in the undulating surface 40, the bottom edges of the multiple outer angle-shaped projections 45 in the multiple outer angle-shaped projection rows 61a, 61b overlap in the tire circumferential direction between radially adjacent outer angle-shaped projection rows 61a, 61b. As a result, the outer angle-shaped projections 45 of radially adjacent outer angle-shaped projection rows 61a, 61b overlap in the tire circumferential direction by an overlap amount d1 in the tire circumferential direction. Therefore, unlike the area between the radially adjacent outer angle-shaped projection rows 61a, 61b of the undulating surface 30 shown in FIG. 5, no annular area is formed between the radially adjacent outer angle-shaped projection rows 61a, 61b that runs along the tire circumferential direction and where no outer angle-shaped projections 45 exist. This improves steering stability on dry roads, as will be described later.

[0051] Furthermore, in the undulating surface 40 of this example, the opposite circumferential ends of the outer angled projections 45 of the outer angled projection rows 61a, 61b adjacent to each other in the tire radial direction do not overlap in the tire radial direction.

[0052] Furthermore, both ends of the undulating surface 40 in the tire radial direction are connected to wall surfaces at both ends in the tire radial direction of an annular recess formed in the tire side surface 13b. The relationship between the tire circumferential pitch and tire radial pitch of the undulating surface 40, the height of the undulating surface 40 being greater than the depth of the annular recess, and the relationship between the tire circumferential pitch Pr and the height of the undulating surface 40 are the same as those in the case of the undulating surface 30.

[0053] As described above, on the tire side surface 13b on the vehicle outer side of the tire 1, the undulating surface 40 undulates in the tire radial and circumferential directions so as to have a plurality of outer angled protrusions 45 in the tire radial and circumferential directions. Furthermore, the undulating surface 40 includes a plurality of outer angled protrusion rows 61a, 61b aligned in the tire radial direction. Each of the outer angled protrusion rows 61a, 61b has a plurality of outer angled protrusions 45 aligned in the tire circumferential direction. Furthermore, the bottom edges of the plurality of outer angled protrusions 45 in the plurality of outer angled protrusion rows 61a, 61b overlap in the tire circumferential direction between the outer angled protrusion rows 61a, 61b adjacent in the tire radial direction.

[0054] This increases the surface area of ​​the tire 1, thereby suppressing internal heat generation, and the edgeless curved shape suppresses turbulence, thereby reducing air resistance. Furthermore, steering stability on dry roads can be improved. Specifically, the undulating curved surface 40 of the tire side surface 13b has a plurality of angled protrusions 45 arranged in the tire radial direction at multiple positions in the tire circumferential direction. In this case, the bottom edges of the outer angled protrusions 45 in the outer angled protrusion rows 61a, 61b of adjacent outer angled protrusion rows 61a, 61b in the tire radial direction overlap in the tire circumferential direction. This makes it difficult for each outer angled protrusion 45 in each angled protrusion row 61a, 61b to deform both in the tire circumferential direction and in a direction inclined relative to the tire circumferential direction, thereby increasing the rigidity per unit area of ​​the tire side surface 13b.

[0055] Generally, when a tire is mounted on a vehicle with a negative camber, the camber angle in the negative direction of the tire on the outer side of the vehicle becomes smaller during cornering, which tends to increase the contact pressure of the tread at the outer edge of the tire. In this example, the undulating surface 40 increases the rigidity per unit area of ​​the tire side surface 13b of the tire on the outer side of the vehicle during cornering. This increases the rigidity in the tire radial direction of the outer portion of the tire on the outer side of the vehicle during cornering on dry roads, thereby improving steering stability. As a result, tire 1, combined with the effect of the undulating surface 30 of the tire side surface 13a, improves steering stability during cornering on dry roads, while also improving braking performance and wear resistance on wet roads.

[0056] Furthermore, according to the tire 1 of the embodiment, even if mud gets into multiple valleys of the undulating curved surfaces 30, 40 on each tire side surface 13a, 13b during running, the angled protrusions 35 bend in the tire radial direction during running, thereby expanding and contracting the spacing between the valleys. This allows the mud that has gotten into the valleys to be easily discharged, improving mud discharge performance.

[0057] Also, as shown in FIGS. 1 and 6, in the embodiment, the undulation surfaces 30, 40 may be configured to be formed on the tire side surfaces 13a, 13b on the respective undulation surfaces 30, 40 within a tire radial direction Y range (within the ranges indicated by arrows η1, η2 in FIGS. 1 and 6) of 25% to 65% 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.

[0058] According to this configuration, the undulating surfaces 30, 40 can be provided in the range from the vicinity of the axially outer ends (P1, P2 in FIG. 1) of the tire side surfaces 13a, 13b corresponding to the maximum tire width, respectively, in the outer portions in the tire radial direction Y, where the air flow is likely to hit, to the outer peripheral portions of the tire that are easily noticeable and have a significant effect on improving the design.

[0059] Fig. 8 is a cross-sectional view showing a tire molding mold of the embodiment. The tire 1 of the present embodiment is formed using a tire molding mold 70. Hereinafter, the tire molding mold 70 will be referred to as the mold 70. The mold 70 is a mold that molds the tire 1 shown in Figs. 1 to 7 described above. The mold 70 makes it possible to realize a tire 1 that is able to suppress an increase in internal heat generation, reduce air resistance, and improve handling stability when the vehicle corners on dry roads and braking performance and wear resistance on wet roads.

[0060] 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.

[0061] 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 72a, 72b for molding the surfaces of the sidewalls.

[0062] 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 .

[0063] 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.

[0064] Of the pair of side molds 72a, 72b, the first side mold 72a includes a main body 76a having a side molding surface 77a for forming the tire side surface 13a on the vehicle inner side. The side molding surface 77a has an annular protrusion 78 that protrudes outward from the side molding surface 77a. The main body 76a is made of the same metal material as the main body 74. The annular protrusion 78 is a part that forms, in the tire 1, an annular recess 37 (FIGS. 2 and 4) having an undulating curved surface 30 on the inner side.

[0065] Of the pair of side molds 72a, 72b, the second side mold 72b includes a main body 76b having a side molding surface 77b for forming the tire side surface 13b on the vehicle outer side. The side molding surface 77b has an annular protrusion 81 that protrudes outward from the side molding surface 77b. The main body 76b is made of the same metal material as the main body 74. The annular protrusion 81 is a portion that forms an annular recess in the tire 1, the annular recess having an undulating curved surface 40 on the inside.

[0066] 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 having an inner diameter corresponding to the outer diameter of the tire 1 to be molded when in a mold clamping state, which will be described later. The upper first side mold 72a is annular, fixed to the underside of an upper plate (not shown) that constitutes a vulcanization molding machine, and rises and falls as a first lifting member (not shown) rises and falls. The lower second side mold 72b is annular, fixed to the floor surface, and fixed to the underside of a lower plate (not shown) that constitutes a vulcanization molding machine. The vulcanization molding machine raises and lowers multiple segments (not shown), each provided for one tread mold 71, outside the multiple divided tread molds 71, using a first lifting member. At the same time as the first lifting member moves up and down, 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. In this way, the vulcanization molding machine moves the multiple segments back and forth radially relative to the central axis of the annularly continuous tread mold 71. In this way, the vulcanization molding machine switches the mold 70 between a mold clamped state and a mold open state.

[0067] 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.

[0068] In this embodiment, an annular protrusion 78 is formed on a side molding surface 77a for forming the tire side surface 13a on the vehicle inner side to form an annular recessed portion 37 having an inner undulating surface 30 on the inner side. An apex 78a of the annular protrusion 78 corresponds to the valley point 38 of the valley portion of the annular recessed portion 37. Furthermore, a mold side curved surface 80 is formed on the side surface of the annular protrusion 78 so as to undulate in the circumferential and radial directions in correspondence with the inner undulating surface 30.

[0069] Additionally, on the side molding surface 77b for forming the tire side surface 13b on the vehicle outer side, an annular protrusion 81 is formed for molding an annular recessed portion having an outer undulating surface 40 on the inside. The apex 81a of the top of the annular protrusion 81 corresponds to the valley point of the valley of the annular recessed portion. Furthermore, on the side surface of the annular protrusion 81, a mold side curved surface 82 is formed so as to undulate in the circumferential and radial directions in correspondence with the outer undulating surface 40.

[0070] The tire obtained using the above tire 1 and mold 70 can suppress an increase in internal heat generation, reduce air resistance, and improve handling stability when the vehicle turns on dry roads, as well as braking performance and wear resistance on wet roads.

[0071] Fig. 9 is a schematic diagram showing the arrangement positions of multiple inner angled protrusions 35 on a portion of the tire circumferential direction on an undulating surface 30a of a tire 1a according to another example of the embodiment. Fig. 10 is a schematic diagram showing the arrangement positions of multiple outer angled protrusions 45 on a portion of the tire circumferential direction on an undulating surface 40a of a tire 1a according to another example of the embodiment.

[0072] In the configuration of this example, as shown in Fig. 9, a wavy surface 30a is provided in an annular recess formed in a tire side surface 13a. Similar to the wavy surface 30 shown in Fig. 5, the wavy surface 30a undulates in the tire radial and circumferential directions so as to have a plurality of inner angled protrusions 35 in the tire radial and circumferential directions. Furthermore, the wavy surface 30a includes a plurality of inner angled protrusion rows 51a, 51b aligned in the tire radial direction. Each inner angled protrusion row 51a, 51b has a plurality of inner angled protrusions 35 aligned in the tire circumferential direction, and the bottom edges of the multiple inner angled protrusions 35 in the multiple inner angled protrusion rows 51a, 51b do not overlap in the tire circumferential direction between inner angled protrusion rows 51a, 51b adjacent in the tire radial direction.

[0073] Furthermore, in this example, on the undulating surface 30a, the tire circumferentially opposite ends of the multiple inner angle-shaped projections 35 of the inner angle-shaped projection rows 51a, 51b adjacent in the tire radial direction overlap in the tire radial direction. Therefore, the inner angle-shaped projections 35 of the inner angle-shaped projection rows 51a, 51b adjacent in the tire radial direction overlap in the tire radial direction by an overlap amount d2 in the tire circumferential direction.

[0074] As a result, in the undulating surface 30a of this example, the inner angled protrusions 35 of the angled-protrusion rows 51a, 51b are less likely to deform in a direction inclined relative to the tire circumferential direction, increasing the rigidity per unit area of ​​the tire side surface 13a, thereby further improving steering stability on dry roads.

[0075] As shown in FIG. 10 , a wavy surface 40a is provided in an annular recess formed in the tire side surface 13b. Similar to the wavy surface 40 shown in FIG. 7 , the wavy surface 40a undulates in the tire radial and circumferential directions to have multiple outer angled protrusions 45 in the tire radial and circumferential directions. Furthermore, the wavy surface 40a includes multiple outer angled protrusion rows 61c, 61d aligned in the tire radial direction. Each outer angled protrusion row 61c, 61d has multiple outer angled protrusions 45 aligned in the tire circumferential direction, and the bottom edges of the multiple outer angled protrusions 45 in the multiple outer angled protrusion rows 61c, 61d adjacent in the tire radial direction overlap in the tire circumferential direction. Therefore, the outer angled protrusions 45 of the outer angled protrusion rows 61c, 61d adjacent in the tire radial direction overlap by a tire radial overlap amount d3 in the tire circumferential direction.

[0076] Furthermore, in this example, on the undulating surface 40a, the tire circumferentially opposite ends of the multiple outer angle-shaped projections 45 of the outer angle-shaped projection rows 61c, 61d adjacent to each other in the tire radial direction overlap in the tire radial direction. Therefore, the outer angle-shaped projections 45 of the outer angle-shaped projection rows 61c, 61d adjacent to each other in the tire radial direction overlap by an overlap amount d4 in the tire radial direction.

[0077] As a result, in the undulating surface 40a of this example, the outer angled protrusions 45 of the angled protrusion rows 61c, 61d are less likely to deform in any of the tire circumferential direction, the tire radial direction, and directions inclined relative to the tire circumferential direction. This further increases the rigidity per unit area of ​​the tire side surface 13a. This further improves steering stability on dry roads. In this example, the other configurations and functions are the same as those of Figures 1 to 8.

[0078] As a combination of undulation surfaces to be provided on the tire side surfaces 13a, 13b, either a combination of the undulation surface 30 shown in Fig. 5 with the undulation surface 40a shown in Fig. 10, or a combination of the undulation surface 30a shown in Fig. 9 with the undulation surface 40 shown in Fig. 7, can be used. On the other hand, of the combinations of the undulation surfaces 30, 30a and the undulation surfaces 40, 40a, the combination of the undulation surface 30a shown in Fig. 9 with the undulation surface 40a shown in Fig. 10 is preferred in terms of achieving the best balance between improved handling stability when the vehicle turns on dry roads and improved braking performance and wear resistance on wet roads.

[0079] In the above embodiment, the tire side surfaces 13a, 13b are provided with the annular portion 100 including the undulating surface 30 and the annular portion 200 including the undulating surface 40, which are continuously formed around the entire circumference in the tire circumferential direction. However, in the above embodiment, instead of the annular portions 100, 200, the tire side surfaces may be provided with an arc-shaped portion that is formed only in a portion of the tire circumferential direction or in multiple locations in the tire circumferential direction and has an arc-shaped recessed portion with an arc-shaped undulating surface formed inside. The arc-shaped portion has an undulating surface that undulates in the tire radial and circumferential directions, formed inside the arc-shaped recessed portion along the tire circumferential direction, so as to have multiple angle-shaped protrusions in the tire radial and circumferential directions. The arc-shaped portion is preferably formed in a band-like area extending in the tire circumferential direction that covers 25% or more of the entire circumference in the tire circumferential direction. The undulating surface may also be formed in, for example, four or more locations in the tire circumferential direction. Furthermore, when the undulating surfaces are arranged at multiple positions in the tire circumferential direction, the total circumferential length of each undulating surface is preferably 50% or more of the total circumferential length of the tire at the radial position of the undulating surface. Regarding the range of the undulating surface in the tire circumferential direction, the proportion of the total circumferential length of the portion where the undulating surface is arranged to the entire circumference of the sidewall is preferably 50% or more, more preferably 80% or more, and most preferably the entire circumference (100%).

[0080] In addition, instead of the annular protrusions 78, 81 formed on the side molding surfaces 77a, 77b of the mold 70 shown in Figure 8, multiple arc-shaped portions having arc-shaped mold side curved surfaces for molding an arc-shaped undulating surface may be formed.

[0081] In the above embodiment, the undulating surface 30 or 40 is formed inside the annular or arc-shaped recess formed in the tire side surfaces 13a, 13b. However, an undulating surface may be formed that protrudes axially outward from the sidewall reference plane of the tire side surface, and that undulates in the tire radial and circumferential directions so as to have multiple angle-shaped protrusions in the tire radial and circumferential directions.

[0082] In addition, in the tire of the above embodiment, a plurality of curved protrusions may be provided on the surface of the undulating curved surface. In addition, in the tire mold of the above embodiment, the molding surface may have a mold-side curved surface corresponding to the undulating curved surface, and a plurality of curved recesses corresponding to the curved protrusions may be formed on the mold-side curved surface. With this configuration, the plurality of curved protrusions on the undulating curved surface are likely to create contrast on the tire side surface. Furthermore, the plurality of curved protrusions on the undulating curved surface are likely to cause air separation. This reduces the negative pressure of the air flowing along the undulating curved surface, thereby reducing air resistance.

[0083] In each of the above embodiments, although not shown in the drawings, markings such as letters, symbols, etc. may be provided on the undulating surface. In each of the above embodiments, when the undulating surface is provided at a portion of the sidewall in the circumferential direction or at multiple positions in the circumferential direction, markings such as letters, symbols, etc. may be provided on a curved surface or smooth surface that is located at the same position in the tire radial direction as the undulating surface and does not have the undulating surface.

[0084] The present disclosure is further illustrated by the following embodiments. Configuration 1: A pair of tire side surfaces that are axially outer surfaces of the tire that are radially inward of the ground contact edges at both axial ends of the tread and radially outward of the rim line, the tire having an inner undulating curved surface provided on the tire side surface that is on the inner side of the vehicle, and an outer undulating curved surface provided on the tire side surface that is on the outer side of the vehicle, the inner undulating curved surface and the outer undulating curved surface are curved surfaces that undulate in the tire radial direction and the tire circumferential direction so as to have a plurality of mountain-shaped protrusions in the tire radial direction and the tire circumferential direction on the tire side surface on the corresponding side, the inner undulating surface includes a plurality of inner angle-shaped projection rows aligned in the tire radial direction, each of the plurality of inner angle-shaped projection rows having a plurality of inner angle-shaped projections that constitute the plurality of angle-shaped projections and are aligned in the tire circumferential direction, bottom edges of the plurality of inner angle-shaped projections in the plurality of inner angle-shaped projection rows do not overlap in the tire circumferential direction between inner angle-shaped projection rows that are adjacent in the tire radial direction, the outer undulating surface includes a plurality of outer angle-shaped projection rows aligned in the tire radial direction, each of the plurality of outer angle-shaped projection rows having a plurality of outer angle-shaped projections that constitute the plurality of angle-shaped projections and are aligned in the tire circumferential direction, and bottom edges of the plurality of outer angle-shaped projections in the plurality of outer angle-shaped projection rows that are adjacent in the tire radial direction overlap in the tire circumferential direction. Pneumatic tires. Configuration 2: The undulating surface of at least one of the inner undulating surface and the outer undulating surface is provided continuously over the entire circumference in the tire circumferential direction. 10. The pneumatic tire according to claim 1. Configuration 3: A recessed portion recessed in the tire axial direction from a sidewall reference plane on one of the tire side surfaces is formed in at least one of the pair of tire side surfaces, and the undulating surface on one of the tire side surfaces is formed so as to rise in the tire axial direction from a bottom surface of the recessed portion. 3. The pneumatic tire according to claim 1 or 2. Configuration 4: The undulating surface of at least one of the inner undulating surface and the outer undulating surface varies periodically in the tire circumferential direction and the tire radial direction, the pitch of one of the undulating surfaces is 3 mm or more and 80 mm or less, and the height of one of the undulating surfaces is 0.3 mm or more and 1.1 mm or less. 4. The pneumatic tire according to any one of claims 1 to 3. Configuration 5: A radius of curvature of a curved surface between peaks and valleys of one of the undulating surfaces is (Pr / 2) or more and ((Pr / H1)+Pr) or less, where Pr is the pitch of one of the undulating surfaces in the tire circumferential direction and H1 is the height of one of the undulating surfaces. 5. The pneumatic tire according to claim 4. Configuration 6: On the inner wavy curved surface, in the inner angle-shaped projection rows adjacent to each other in the tire radial direction, opposite end portions in the tire circumferential direction of the plurality of inner angle-shaped projections overlap in the tire radial direction. 6. A pneumatic tire according to any one of claims 1 to 5. Configuration 7: In the outer wavy surface, in the outer angle-shaped projection rows adjacent to each other in the tire radial direction, opposite end portions in the tire circumferential direction of the plurality of outer angle-shaped projections overlap in the tire radial direction. 7. The pneumatic tire of any one of claims 1 to 6. Configuration 8: The undulation surface of at least one of the inner undulation surface and the outer undulation surface is formed on the tire side surface on the side of one of the undulation surfaces within a tire radial range of 25% to 65% when the tire radial position of the rim line or the tire axially outer end of the rim protector is set to 0 and the tire cross-sectional height is set to 100. 8. The pneumatic tire of any one of configurations 1 to 7. Configuration 9: A pneumatic tire mold for molding the pneumatic tire according to any one of Configurations 1 to 8, a first side mold having a first mold-side curved surface on its molding surface that corresponds to the outer undulation curved surface; and a second side mold having a second mold-side curved surface on its molding surface that corresponds to the inner undulation curved surface. Mold for molding pneumatic tires. [Explanation of symbols]

[0085] 1, 1a pneumatic tire (tire), 10 tread, 11a, 11b block, 11c circumferential groove, 12a, 12b sidewall, 13a, 13b tire side surface, 14a, 14b sidewall reference surface, 15 bead, 18 rim strip, 19 rim protector, 20 rim line, 30, 30a inner undulating surface (undulating surface), 31 vertex, 35 inner chevron protrusion, 37 annular recess, 38 valley point, 39 opening edge, 40 outer undulating surface (undulating surface), 41 vertex, 45 outer chevron protrusion, 51, 51a, 51b inner chevron protrusion row, 52 undulation portion, 54 annular region, 61a, 61b, 61c, 61d outer chevron protrusion row, 62 undulation portion, 70 Tire molding mold, 71 tread mold, 72a first side mold, 72b second side mold, 73 tread molding surface, 74 main body, 75 protrusions, 76a, 76b main body, 77a, 77b side molding surface, 78 annular protrusion, 78a vertex, 80 mold side curved surface, 81 annular protrusion, 81a vertex, 82 mold side curved surface, 100, 200 annular portion, T1, T2 ground contact edge.

Claims

1. The tire has a pair of tire side surfaces that are axially outer surfaces of the tire that are radially inward of the ground contact edges at both axial ends of the tread and radially outward of the rim line, and the tire has an inner undulating curved surface provided on the tire side surface that is on the inner side of the vehicle, and an outer undulating curved surface provided on the tire side surface that is on the outer side of the vehicle, the inner undulating curved surface and the outer undulating curved surface are curved surfaces that undulate in the tire radial direction and the tire circumferential direction so as to have a plurality of mountain-shaped protrusions in the tire radial direction and the tire circumferential direction on the tire side surface on the corresponding side, the inner undulating surface includes a plurality of inner angle-shaped projection rows aligned in the tire radial direction, each of the plurality of inner angle-shaped projection rows having a plurality of inner angle-shaped projections that constitute the plurality of angle-shaped projections and are aligned in the tire circumferential direction, bottom edges of the plurality of inner angle-shaped projections in the plurality of inner angle-shaped projection rows do not overlap in the tire circumferential direction between inner angle-shaped projection rows that are adjacent in the tire radial direction, the outer undulating surface includes a plurality of outer angle-shaped projection rows aligned in the tire radial direction, each of the plurality of outer angle-shaped projection rows having a plurality of outer angle-shaped projections that constitute the plurality of angle-shaped projections and are aligned in the tire circumferential direction, and bottom edges of the plurality of outer angle-shaped projections in the plurality of outer angle-shaped projection rows that are adjacent in the tire radial direction overlap in the tire circumferential direction. Pneumatic tires.

2. the undulating surface of at least one of the inner undulating surface and the outer undulating surface is provided continuously over the entire circumference in the tire circumferential direction; The pneumatic tire according to claim 1 .

3. a recessed portion recessed in the tire axial direction from a sidewall reference plane on one of the tire side surfaces is formed in at least one of the pair of tire side surfaces, and the undulating surface on one of the tire side surfaces is formed so as to rise in the tire axial direction from a bottom surface of the recessed portion. The pneumatic tire according to claim 1 .

4. the undulation surface of at least one of the inner undulation surface and the outer undulation surface varies periodically in the tire circumferential direction and the tire radial direction, the pitch of one of the undulation surfaces is 3 mm or more and 80 mm or less, and the height of one of the undulation surfaces is 0.3 mm or more and 1.1 mm or less; The pneumatic tire according to claim 1 .

5. a radius of curvature of a curved surface between peaks and valleys of one of the undulating surfaces is (Pr / 2) or more ((Pr / H1)+Pr) or less, where Pr is a pitch of the one of the undulating surfaces in the tire circumferential direction and H1 is a height of the one of the undulating surfaces; The pneumatic tire according to claim 4.

6. On the inner wavy curved surface, between the inner angle-shaped projection rows adjacent in the tire radial direction, opposite end portions in the tire circumferential direction of the plurality of inner angle-shaped projections overlap in the tire radial direction. The pneumatic tire according to claim 1 .

7. On the outer wavy curved surface, between the outer angle-shaped projection rows adjacent in the tire radial direction, opposite end portions in the tire circumferential direction of the plurality of outer angle-shaped projections overlap in the tire radial direction. The pneumatic tire according to claim 1 .

8. the undulation surface of at least one of the inner undulation surface and the outer undulation surface is formed on the tire side surface on one of the undulation surfaces within a tire radial range of 25% to 65% when the tire radial position of the rim line or the tire axially outer end of the rim protector is set to 0 and the tire cross-sectional height is set to 100; The pneumatic tire according to claim 1 .

9. A pneumatic tire mold for molding the pneumatic tire according to any one of claims 1 to 8, a first side mold having a first mold-side curved surface on its molding surface that corresponds to the outer undulation curved surface; and a second side mold having a second mold-side curved surface on its molding surface that corresponds to the inner undulation curved surface. Mold for molding pneumatic tires.

Images