Pneumatic tire

Abstract

To provide a pneumatic tire having a side wall which is high in design property and excellent in crack resistance.SOLUTION: In a pneumatic tire according to an embodiment, a first display area 10 and a second display area 11 are provided in parallel in a tire circumferential direction in a side wall, a plurality of letters 15 are provided in the first display area 10 and decorations in which a plurality of protrusions 31 are arranged in a recess 30 with respect to a tire surface are made in the second display area 11. The decorations include a first decoration 20 in a shape in which letters are stylized and second decorations 21 which are different in shape from the first decoration 20. The first decoration 20 and the second decorations 21 are arranged adjacently, and a length in a tire radial direction of the first decoration 20 is shorter than lengths in the tire radial direction of the second decorations 21.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a pneumatic tire.

Background Art

[0002] There is known a pneumatic tire provided with a display area in which a plurality of characters are arranged and a display area composed of serrations on a sidewall (see, for example, Patent Document 1). A serration is a structure in which a large number of ridges extending long are arranged at regular intervals inside a wide and shallow recess formed on the tire surface. The ridges inside the recess are called ridges.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in order to enhance the decorativeness of the sidewall, the inventor has considered adding a highly designed decoration to the display area provided with serrations. And the inventor has considered forming the additional decoration also as serrations. However, since the rubber constituting the pneumatic tire becomes thin at the location of the serrations, simply adding serrations may cause problems such as crack generation.

[0005] Therefore, an object of the present invention is to provide a pneumatic tire having a sidewall with high design and good crack resistance.

Means for Solving the Problems

[0006] The pneumatic tire according to the embodiment has a first display area and a second display area provided side by side in the tire circumferential direction on at least one of the sidewalls on both sides in the tire axial direction. A plurality of characters are provided in the first display area, and in the second display area, a decoration in which a plurality of ridges are arranged in a recess with respect to the tire surface is provided. As the decoration, a first decoration having a shape in which characters are designed, and a second decoration having a shape different from that of the first decoration , a third decoration having a different shape from the first decoration and the second decoration are provided, and the first decoration and the second decoration are arranged adjacent to each other, The third decoration is provided at a location inside the tire diameter direction of a part of the first decoration. and the length of the first decoration in the tire radial direction is shorter than the length of the second decoration in the tire radial direction Furthermore, the first decoration, the second decoration, and the third decoration have the same depth of the recess, and the direction and angle of the inclination of the rib with respect to the tire diameter direction are the same. characterized in that.

Effect of the Invention

[0007] Since the sidewall of the pneumatic tire according to the embodiment has the above characteristics, it has high designability and good crack resistance.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0009] First, the overall structure of the pneumatic tire 1 of the present embodiment will be described with reference to FIG. 1. Note that only half of the tire in the tire axial direction is shown in FIG. 1, and the actual pneumatic tire 1 is symmetric about the tire center line C. The vertical direction in FIG. 1 is the tire radial direction, the left-right direction is the tire axial direction, and the direction perpendicular to the paper surface is the tire circumferential direction.

[0010] In the pneumatic tire 1, bead portions 9 are provided on both sides in the tire axial direction (only the right side in FIG. 1). The bead portion 9 is composed of a bead core 9a made of steel wire and a rubber bead filler 9b provided on the radially outer side of the bead core 9a.

[0011] One or more carcass plies 2 are stretched across the bead portions 9 on both sides in the tire axial direction. The carcass ply 2 is a sheet-like member in which a large number of ply cords arranged in a direction perpendicular to the tire circumferential direction are covered with rubber. The carcass ply 2 forms the skeletal shape of the pneumatic tire 1 between the bead portions 9 on both sides in the tire axial direction. Further, the carcass ply 2 is folded back from the inner side to the outer side in the tire axial direction around the bead portion 9 and wound up to the radially outer side of the tire. A rubber chafer 3 is provided at a location on the outer side in the tire axial direction of the portion 2a of the carcass ply 2 wound up to the radially outer side of the tire.

[0012] Also, one or more belts 4 are provided on the radially outer side of the carcass ply 2, and a belt reinforcing layer 5 is provided on the radially outer side of the belt 4. The belt 4 is a member formed by covering a large number of steel cords with rubber. The belt reinforcing layer 5 is a member formed by covering a large number of cords made of organic fibers with rubber. A tread rubber 6 is provided on the radially outer side of the belt reinforcing layer 5. A large number of grooves are provided in the tread rubber 6 to form a tread pattern.

[0013] In addition, sidewall rubbers 7 are provided on both sides of the carcass ply 2 in the tire axial direction. The tread rubber 6 and the sidewall rubbers 7 overlap in the beltless tire, and either the tread rubber 6 or the sidewall rubbers 7 may be on the tire surface side. In the beltless tire of FIG. 1, the tread rubber 6 is on the tire surface side. Although not shown, wing rubbers may be provided in the beltless tire. The portion of the sidewall rubber 7 on the inner side in the tire radial direction extends close to the bead portion 9 and covers a part of the rubber chafer 3 from the outer side in the tire axial direction. In the present embodiment, not only the portion where the sidewall rubber 7 appears on the tire surface but also the entire visible range when the pneumatic tire 1 is viewed from the tire axial direction is defined as the sidewall.

[0014] In addition to these members, members such as a belt under pad are provided on the pneumatic tire 1 as necessary.

[0015] Next, the display area of the sidewall will be described.

[0016] As shown in FIG. 2, on at least one of the sidewalls on both sides in the tire axial direction, two first display areas 10 and two second display areas 11 are alternately arranged in the tire circumferential direction. These display areas 10 and 11 are provided in a display band 12 (see FIG. 2) that makes one turn in the tire circumferential direction. The display band 12 is a region having a constant width in the tire radial direction, sandwiched between an inner diameter side line 13 that draws a small-diameter circle and an outer diameter side line 14 that draws a large-diameter circle. These lines 13 and 14 are formed as steps on the tire surface.

[0017] A plurality of characters 15 are arranged in the tire circumferential direction in the first display area 10. By these plurality of characters 15, the manufacturer name, product name, brand, etc. are displayed. These characters 15 have a shape that can be clearly distinguished as to what kind of characters they are for the purpose of displaying the manufacturer name, etc. In addition, each character 15 is formed by being bordered by a boundary line between the portion of the character 15 itself and the surrounding portion.

[0018] Further, as shown in FIGS. 2 and 3, the second display area 11 is provided with a first decoration 20, a second decoration 21, and a third decoration 22. One second display area 11 is provided with one first decoration 20 and one third decoration 22 respectively, and three second decorations 21 are provided. The first decoration 20 is arranged sandwiched between two second decorations 21 from both sides in the tire circumferential direction. Further, the third decoration 22 is provided at a location on the inner diameter side of a part of the first decoration 20.

[0019] The first decoration 20 has a shape in which characters (not necessarily the same characters as those in the first display area 10) are designed. The design of the characters is performed by methods such as thickening the characters, deforming a part of the characters, connecting (or conversely separating) parts that are originally separated in the lines for drawing the characters, simplifying the characters, abstracting the characters, and the like. The degree of design is more advanced than the characters 15 in the first display area 10 and is such that a person can recall the characters when seeing them.

[0020] The first decoration 20 of the present embodiment is one in which the number "7" is designed. Specifically, the number "7" is thickly drawn and has a somewhat trendy shape. The number "7" that is the basis of the design consists of a line extending in the tire circumferential direction of the first stroke and a line extending in the tire radial direction of the second stroke, and both of these two lines are thickly drawn.

[0021] The first decoration 20 in which the number "7" is designed is bordered by a boundary line with the surroundings. As the boundary line, there are a circumferential boundary line extending in the tire circumferential direction and a radial boundary line extending from the inner side in the tire radial direction to the outer side in the tire radial direction.

[0022] As shown in FIG. 4, as the circumferential boundary line of the first decoration 20 in which the number "7" is designed, there are a first circumferential boundary line 23a at the upper end of the portion corresponding to the first stroke line, a second circumferential boundary line 23b at the lower end of the same portion, and a third circumferential boundary line 23c at the lower end of the portion corresponding to the second stroke line.

[0023] Also, as shown in FIG. 4, as the radial boundary lines of the first decoration 20, there are a first radial boundary line 24a at the left end of the portion corresponding to the first line of the above, a second radial boundary line 24b at the left end of the portion corresponding to the second line of the above, a third radial boundary line 24c at the right end of the portion corresponding to the second line of the above, and a fourth radial boundary line 24d at the right end of the portion corresponding to the corner of the number "7".

[0024] Among these radial boundary lines, the first radial boundary line 24a, the second radial boundary line 24b, and the third radial boundary line 24c, which account for 3 / 4 of them, are inclined to the right with respect to the tire radial direction (that is, they are inclined to the right as they go toward the outer side of the tire radial direction). The remaining fourth radial boundary line 24d is inclined to the left with respect to the tire radial direction (that is, it is inclined to the left as it goes toward the outer side of the tire radial direction).

[0025] As shown in FIGS. 2 and 3, the three second decorations 21 are each a portion having a shape that does not evoke a character. The three second decorations 21 each extend in the tire circumferential direction while having a predetermined width in the tire radial direction. The maximum widths of the three second decorations 21 in the tire radial direction are the same.

[0026] The three second decorations 21 are each bordered by a boundary line with the surrounding area. As the boundary line, there are a circumferential boundary line extending in the tire circumferential direction and a radial boundary line extending from the inner side to the outer side of the tire radial direction. In each of the second decorations 21, only one circumferential boundary line is provided on the outer side and the inner side of the tire radial direction, and the radial boundary lines connect the right ends and the left ends of these two circumferential boundary lines, respectively.

[0027] As the radial boundary lines of the three second decorations 21, there are a first radial boundary line 25a at the left end of the leftmost second decoration 21, a second radial boundary line 25b at the right end of the leftmost second decoration 21, a third radial boundary line 25c on the outer side in the tire radial direction at the left end of the second second decoration 21 from the left, a fourth radial boundary line 25d on the inner side in the tire radial direction at the left end of the second second decoration 21 from the left, a fifth radial boundary line 25e at the right end of the second second decoration 21 from the left, a sixth radial boundary line 25f at the left end of the rightmost second decoration 21, and a seventh radial boundary line 25g at the right end of the rightmost second decoration 21.

[0028] Among these radial boundary lines, the third radial boundary line 25c and the fourth radial boundary line 25d are connected, thereby forming a single line that bends in the middle.

[0029] Also, among these radial boundary lines, the second radial boundary line 25b, the fourth radial boundary line 25d, the fifth radial boundary line 25e, the sixth radial boundary line 25f, and the seventh radial boundary line 25g are inclined to the right with respect to the tire radial direction. The remaining first radial boundary line 25a and third radial boundary line 25c are inclined to the left with respect to the tire radial direction.

[0030] Further, the third decoration 22 has a shape that fills the lower left space of the first decoration 20 in which the number "7" is designed. The third decoration 22 is also bordered by a boundary line with the surroundings. As shown in FIG. 4, as the boundary line, there are three circumferential boundary lines extending in the tire circumferential direction and three radial boundary lines 27a, 27b, 27c extending from the inner side in the tire radial direction to the outer side in the tire radial direction. All three radial boundary lines 27a, 27b, 27c are inclined to the right with respect to the tire radial direction.

[0031] There are a total of 14 radial boundary lines in the second display area 11, and 11 radial boundary lines, which account for more than 3 / 4 of them, are inclined to the right with respect to the tire radial direction.

[0032] The tire radial length of the above-described first decoration 20 is shorter than the tire radial length of each of the three second decorations 21. Specifically, as shown in FIG. 3, the third circumferential boundary line 23c corresponding to the inner end of the first decoration 20 in the tire radial direction is located on the outer side in the tire radial direction compared to the circumferential boundary lines 26a, 26b, and 26c corresponding to the inner ends of the three second decorations 21 in the tire radial direction. Also, the first circumferential boundary line 23a corresponding to the outer end of the first decoration 20 in the tire radial direction is located on the inner side in the tire radial direction compared to the circumferential boundary lines 26d, 26e, and 26f corresponding to the outer ends of the three second decorations 21 in the tire radial direction. Therefore, on the inner and outer sides of the first decoration 20 in the tire radial direction, there are formed locations 29 (see FIG. 4) that are narrow in the tire radial direction but have no decoration as serrations.

[0033] The tire radial length of the first decoration 20 (the length in the direction orthogonal to the tire axial direction, not the length along the tire surface) is desirably 75% or more and 80% or less of the tire radial length of the second decoration 21. Also, the tire radial length of the first decoration 20 is desirably 15% or more and 20% or less of the tire section height (the length indicated by H in FIG. 1).

[0034] Such a first decoration 20 is entirely formed as serrations. A cross-sectional view of the serrations is shown in FIG. 5. FIG. 5 is a cross-sectional view taken along line A-A of FIG. 3. As shown in FIG. 5, a serration is a portion formed by a number of ridges 31 extending in one direction being arranged at regular intervals in the tire circumferential direction within a shallow and wide recess 30 formed on the tire surface. Here, the ridge 31 is a convex strip that protrudes from the bottom surface of the recess 30 and extends long along the inner surface of the recess 30.

[0035] Note that each of the above boundary lines consists of a step between the recess 30 and the surrounding portion.

[0036] As the cross-sectional shape in the direction orthogonal to the longitudinal direction of the ridge 31, in addition to the semi-circular shape shown in FIG. 5, there are a triangular shape shown in FIG. 6, a trapezoidal shape shown in FIG. 7, etc. Note that the numerous lines drawn on the first decoration 20 in FIGS. 2 to 4 are the center lines of the ridges 31.

[0037] The pitch P of the ridges 31 (the shortest distance between the vertices of two adjacent ridges 31, see Fig. 5) is, for example, 0.4 mm or more and 2.0 mm or less. Also, the height h of the ridges 31 (see Fig. 5) is, for example, 0.2 mm or more and 3.0 mm or less.

[0038] All the ridges 31 in the first decoration 20 are inclined at the same angle in the same direction with respect to the tire radial direction. As shown in Figs. 2 to 4, these ridges 31 are inclined to the left with respect to the tire radial direction (that is, they are inclined to the left as they go toward the outer side in the tire radial direction). As described above, the first radial boundary line 24a, the second radial boundary line 24b, and the third radial boundary line 24c, which correspond to 3 / 4 of the radial boundary line of the first decoration 20, are inclined to the right with respect to the tire radial direction, and the ridges 31 of the first decoration 20 are inclined in the opposite direction to those radial boundary lines.

[0039] Also, all of the second decoration 21, the third decoration 22, and all the characters 15 are each entirely formed as serrations. And in the first decoration 20, the second decoration 21, the third decoration 22, and the characters 15, the depth of the recesses 30 is the same. Also, in the first decoration 20, the second decoration 21, the third decoration 22, and the characters 15, the cross-sectional shape of the ridges 31, the pitch P, the height h, the inclination direction with respect to the tire radial direction, and the inclination angle with respect to the tire radial direction are the same.

[0040] Note that the lines drawn in the second decoration 21 and the third decoration 22 in Figs. 2 to 4 are the center lines of the ridges 31. Although there are also a number of ridges 31 in the characters 15, they are not shown in the figures.

[0041] As described above, more than 3 / 4 of the radial boundary lines of the radial boundary lines of the second display area 11 are inclined to the right with respect to the tire radial direction, and the ridges 31 of the second display area 11 are inclined in the opposite direction to these radial boundary lines.

[0042] Note that the peripheries of the first decoration 20, the second decoration 21, the third decoration 22, and the characters 15 are smooth surfaces.

[0043] Two first display areas 10 and two second display areas 11 are respectively provided on one side wall, and the above features are common to the two first display areas 10 and the two second display areas 11.

[0044] The first display area 10 and the second display area 11 as described above may also be provided on the side wall on the opposite side of FIG. 1.

[0045] Next, the effects of this embodiment will be described.

[0046] As described above, in the second display area 11 of the pneumatic tire 1 of this embodiment, the second decoration 21 as a typical serration and the first decoration 20 in the shape of a designed character are arranged adjacent to each other. Thereby, the decorativeness of the side wall is enhanced. Here, since the first decoration 20 is also formed as a serration like the second decoration 21, a sense of unity is generated between the first decoration 20 and the second decoration 21, and the decorativeness is enhanced.

[0047] In addition, since the length of the first decoration 20 in the tire radial direction is shorter than the length of the second decoration 21 in the tire radial direction, the area of the portion where the rubber is thinned by the first decoration 20 is suppressed to be small. Therefore, cracks are less likely to occur.

[0048] Also, cracks may occur at the inner or outer end of the second decoration 21 in the tire radial direction, and the cracks may extend in the tire circumferential direction. However, in this embodiment, since the first decoration 20 is short in the tire radial direction, there is no serration as the first decoration 20 at the circumferential location of the inner or outer end of the second decoration 21 in the tire radial direction (the non-decorated location 29 in FIG. 4), and the rubber at that location is thick. Therefore, cracks are less likely to extend.

[0049] In this way, the pneumatic tire 1 of this embodiment has a side wall with high design and good crack resistance.

[0050] In addition, in the present embodiment, since the first decoration 20 is disposed with the two second decorations 21 sandwiching it from both sides in the tire circumferential direction, the first decoration 20 having a shape in which characters are designed is more prominent, and the design property of the sidewall is high.

[0051] In addition, in the present embodiment, the depth of the recess 30 is the same between the first decoration 20 and the second decoration 21, and the direction and angle of the inclination of the ridge 31 with respect to the tire radial direction are the same. Therefore, a sense of unity is generated between the first decoration 20 and the second decoration 21, and the decorativeness is enhanced. Further, since the cross-sectional shape, pitch P, and height h of the ridge 31 are also the same between the first decoration 20 and the second decoration 21, the sense of unity between the first decoration 20 and the second decoration 21 is enhanced.

[0052] In addition, the third decoration 22 also has the same characteristics as the first decoration 20 with respect to the recess 30 and the ridge 31. As a result, all the decorations 20, 21, 22 in the second display area 11 have common characteristics with respect to the recess 30 and the ridge 31, so the sense of unity of the entire second display area 11 is enhanced.

[0053] In addition, the characters 15 in the first display area 10 are formed as serrations, and further, since the depth of the recess 30 of the serrations is the same as the depth of the recess 30 in the first decoration 20, a sense of unity is generated between the characters 15 in the first display area 10 and the first decoration 20, and the decorativeness of the sidewall is enhanced. Further, since the direction and angle of the inclination of the ridge 31 with respect to the tire radial direction, the cross-sectional shape of the ridge 31, the pitch P, and the height h are the same between the characters 15 in the first display area 10 and the first decoration 20, the sense of unity between the characters 15 in the first display area 10 and the first decoration 20 is enhanced.

[0054] In addition, when the pneumatic tire 1 is inflated, it is known that recessed streaks extending in the tire radial direction are generated on the sidewall. However, in the present embodiment, since a large number of ridges 31 extend while being inclined with respect to the tire radial direction, the above-mentioned streaks extending in the tire radial direction are difficult to see, and the appearance is good.

[0055] In addition, since each radial boundary line that demarcates the first decoration 20, the second decoration 21, and the third decoration 22 of the second display area 11 extends obliquely with respect to the tire radial direction, the above-mentioned ribs that extend in the tire radial direction during inflation are less visible and the appearance is good.

[0056] Moreover, since 3 / 4 or more of all the radial boundary lines in the second display area 11 are inclined in the same direction with respect to the tire radial direction, the design property of the sidewall is high. Further, since the inclination direction of 3 / 4 or more of all the radial boundary lines in the second display area 11 with respect to the tire radial direction is opposite to the inclination direction of the ridge 31 in the second display area 11 with respect to the tire radial direction, the design property of the sidewall is even higher, and the above-mentioned ribs that extend in the tire radial direction during inflation are even less visible.

[0057] The above embodiments are merely examples, and various modifications can be made to the above embodiments.

[0058] In the above embodiment, the second decoration 21 is arranged on both sides in the tire circumferential direction of the first decoration 20. However, as a modification example, the second decoration 21 may be arranged only on one side in the tire circumferential direction of the first decoration 20. For example, the first decoration 20 may be arranged at the tire circumferential end of the second display area 11, and the second decoration 21 may be arranged adjacent to one side in the tire circumferential direction thereof. Even in such a case, the design property of the sidewall is high and the crack resistance is also good.

[0059] In addition, at least a part of the depth of the recess 30 or the inclination direction, the inclination angle, the cross-sectional shape, the pitch P, or the height h of the ridge 31 with respect to the tire radial direction may be different from others in a part of the first decoration 20, the second decoration 21, the third decoration 22, and the character 15. In particular, since the character 15 is located away from the first decoration 20, the second decoration 21, and the third decoration 22, the depth of the recess 30 or the characteristics of the ridge 31 may be different from those of the first decoration 20, the second decoration 21, and the third decoration 22.

Explanation of Reference Numerals

[0060] C…Tire center line, 1…Pneumatic tire, 2…Carcass ply, 2a…Turn-up portion, 3…Rubber chafer, 4…Belt, 5…Belt reinforcing layer, 6…Tread rubber, 7…Sidewall rubber, 9…Bead portion, 9a…Bead core, 9b…Bead filler, 10…First display area, 11…Second display area, 12…Display band, 13…Inner diameter side line, 14…Outer diameter side line, 15…Characters, 20…First decoration, 21…Second decoration, 22…Third decoration, 23a…First circumferential boundary line, 23b…Second circumferential boundary line, 23c…Third circumferential boundary line, 24a…First radial boundary line, 24b…Second radial boundary line, 24c…Third radial boundary line, 24d…Fourth radial boundary line, 25a…First radial boundary line, 25b…Second radial boundary line, 25c…Third radial boundary line, 25d…Fourth radial boundary line, 25e…Fifth radial boundary line, 25f…Sixth radial boundary line, 25g…Seventh radial boundary line, 26a…Circumferential boundary line, 26b…Circumferential boundary line, 26c…Circumferential boundary line, 26d…Circumferential boundary line, 26e…Circumferential boundary line, 26f…Circumferential boundary line, 27a…Radial boundary line, 27b…Radial boundary line, 27c…Radial boundary line, 29…Location without decoration, 30…Indentation, 31…Ridge

Claims

1. In a pneumatic tire in which a first display area and a second display area are provided side by side in the tire circumferential direction on at least one of the sidewalls on both sides in the tire axial direction, a plurality of characters are provided in the first display area, and a decoration in which a plurality of ridges are arranged in a recess with respect to the tire surface is provided in the second display area, as the decoration, a first decoration having a shape in which characters are designed into a pattern, a second decoration having a shape different from that of the first decoration, and a third decoration having a shape different from those of the first decoration and the second decoration are provided, the first decoration and the second decoration are arranged adjacent to each other, the third decoration is provided at a location radially inside a part of the first decoration in the tire diameter direction, the length of the first decoration in the tire diameter direction is shorter than the length of the second decoration in the tire diameter direction, the first decoration, the second decoration, and the third decoration have the same depth of the recess and the same direction and angle of inclination of the ridges with respect to the tire diameter direction, a pneumatic tire.

2. The pneumatic tire according to claim 1, wherein the first decoration and the second decoration have the same depth of the recess and the same direction and angle of inclination of the ridges with respect to the tire diameter direction.

3. The first decoration and the second decoration are each bordered by a boundary line with the surroundings, and as the boundary line, a circumferential boundary line extending in the tire circumferential direction and a radial boundary line extending from the inside in the tire diameter direction to the outside in the tire diameter direction are provided, The pneumatic tire according to claim 2, wherein the inclination direction of more than 3 / 4 of the radial boundary lines in the tire diameter direction in the second display area is opposite to the inclination direction of the ridges in the tire diameter direction in the first decoration and the second decoration.

4. The pneumatic tire according to any one of claims 1 to 3, wherein the first decoration is arranged sandwiched between the two second decorations from both sides in the tire circumferential direction.

5. The pneumatic tire according to any one of claims 1 to 3, wherein the second decoration is arranged only on one side in the tire circumferential direction of the first decoration.

6. The plurality of characters in the first display area are formed by arranging a plurality of ridges side by side in a recess with respect to the tire surface, The pneumatic tire according to any one of claims 1 to 5, wherein the first decoration and the plurality of characters in the first display area have the same depth of the recess.

Images