Tire

Abstract

This tire comprises a marked portion 2 that is formed on a tire side surface. The marked portion 2 comprises a housing 21 which is formed on the tire side surface and a plurality of ridges 22 which protrude from the bottom surface of the housing 21 and are arranged in parallel in a prescribed direction. The ratio of the height H22 of the ridges 22 to the depth H21 of the housing 21 is within the range of 1.00 ≤ H22 / H21. The pitch length P22 of the plurality of ridges 22 is within the range of 0.05 [mm] ≤ P22 ≤ 0.50 [mm].

Description

tire

[0001] The present invention relates to a tire, and more particularly to a tire that can improve the visibility of a marking and the wax retention performance.

[0002] In recent tires, there is a problem that markings (such as tire manufacturer and tire brand) formed on the tire side portion should be colored black to improve visibility. A technology described in Patent Document 1 is known as a conventional tire that addresses this problem.

[0003] At the same time, there is also a need to prevent the wax applied to the tire side from peeling off and improve the wax retention performance. A technology described in Patent Document 2 is known as a conventional tire that addresses this issue.

[0004] European Patent Application Publication No. 3030432 Japanese Patent Application Laid-Open No. 2021-059261

[0005] An object of the present invention is to provide a tire that can improve the visibility of the markings and the wax retention performance.

[0006] In order to achieve the above object, the tire of the present invention is a tire having a marking portion formed on the tire side surface, wherein the marking portion comprises a housing formed on the tire side surface and a plurality of ridges protruding from the bottom surface of the housing and arranged in parallel in a predetermined direction, wherein the height H22 of the ridges is in the range of 1.00≦H22 / H21 relative to the depth H21 of the housing, and the pitch length P22 of the plurality of ridges is in the range of 0.05 [mm]≦P22≦0.50 [mm].

[0007] In the tire according to the present invention, (1) the marking portion is composed of a plurality of ridges arranged within the housing, and therefore the marking portion is blackened in a plan view of the tire sidewall, improving the visibility of the marking portion and also improving the retention of wax applied to the marking portion. Furthermore, (2) the ridge height H22 is within the above-mentioned range relative to the housing depth H21, making it easier for wax to be applied to the ridge tops, further improving the retention of wax in the marking portion. Furthermore, (3) the pitch length P22 of the plurality of ridges is within the above-mentioned range, improving the blackening effect of the ridges on the marking portion. These advantages result in improved visibility of the marking portion and improved wax retention.

[0008] FIG. 1 is a cross-sectional view in the tire meridian direction showing a tire according to an embodiment of the present invention. FIG. 2 is a plan view showing a tire side portion of the tire shown in FIG. 1. FIG. 3 is an enlarged view showing a marking on the tire side portion shown in FIG. 2. FIG. 4 is an explanatory diagram showing a marking on the tire side portion shown in FIG. 2. FIG. 5 is an explanatory diagram showing a marking on the tire side portion shown in FIG. 2. FIG. 6 is an explanatory diagram showing a marking on the tire side portion shown in FIG. 2. FIG. 7 is an explanatory diagram showing a modified example of the tire shown in FIG. 6. FIG. 8 is an explanatory diagram showing a modified example of the tire shown in FIG. 6. FIG. 9 is an explanatory diagram showing a modified example of the tire shown in FIG. 6. FIG. 10 is a table showing the results of a performance test of a tire according to an embodiment of the present invention.

[0009] The present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these embodiments. Furthermore, the components of these embodiments include those that can be substituted and are obvious substitutes while maintaining the identity of the invention. Furthermore, the multiple modifications described in these embodiments can be arbitrarily combined within the scope obvious to those skilled in the art.

[0010] [Tire] Fig. 1 is a cross-sectional view in the tire meridian direction showing a tire 1 according to an embodiment of the present invention. The figure shows a cross-sectional view of one side region in the tire radial direction of the tire 1 mounted on a rim 20. In this embodiment, a pneumatic radial tire for passenger cars will be described as an example of a tire.

[0011] In the figure, the tire meridian cross section is defined as a cross section of the tire cut by a plane including the tire rotation axis (not shown). The tire equatorial plane CL is defined as a plane that passes through the midpoint of the tire section width defined by JATMA and is perpendicular to the tire rotation axis. The tire width direction is defined as a direction parallel to the tire rotation axis, and the tire radial direction is defined as a direction perpendicular to the tire rotation axis. Point T is the tire ground contact edge, and point Ac is the tire's maximum width position.

[0012] The tire 1 has an annular structure centered on the tire rotation axis, and includes a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a carcass layer 13, a belt layer 14, a tread rubber 15, a pair of sidewall rubbers 16, 16, and a pair of rim cushion rubbers 17, 17 (see Figure 1).

[0013] The pair of bead cores 11, 11 are formed by winding one or more steel bead wires in an annular and multiple manner, and are embedded in the bead portions to form the cores of the left and right bead portions. The pair of bead fillers 12, 12 are disposed on the outer peripheries of the pair of bead cores 11, 11 in the tire radial direction, respectively, to reinforce the bead portions.

[0014] The carcass layer 13 has a single-layer structure consisting of one carcass ply or a multi-layer structure consisting of multiple carcass plies stacked together, and is toroidally laid between the left and right bead cores 11, 11 to form the tire framework. Both ends of the carcass layer 13 are wrapped around and secured to the outside in the tire width direction so as to enclose the bead cores 11 and the bead fillers 12. The carcass ply of the carcass layer 13 is formed by coating multiple carcass cords made of steel or organic fiber material (e.g., aramid, nylon, polyester, rayon, etc.) with coating rubber and rolling them, and has a cord angle (defined as the inclination angle of the carcass cords in the longitudinal direction with respect to the tire circumferential direction) of 80 degrees or more and 100 degrees or less.

[0015] The belt layer 14 is formed by laminating a plurality of belt plies 141 to 143, and is disposed by being wound around the outer periphery of the carcass layer 13. The belt plies 141 to 143 each include a pair of cross belts 141, 142 and a belt cover 143.

[0016] The pair of cross belts 141, 142 are formed by coating a plurality of belt cords made of steel or organic fiber material with coating rubber and rolling them, and have a cord angle (defined as the inclination angle of the belt cords in the longitudinal direction with respect to the tire circumferential direction) of 15 degrees or more and 55 degrees or less in absolute value. The pair of cross belts 141, 142 have cord angles of opposite signs to each other, and are layered with the belt cords' longitudinal directions crossing each other (a so-called cross-ply structure). The pair of cross belts 141, 142 are layered on the tire radially outer side of the carcass layer 13.

[0017] The belt cover 143 is formed by covering a belt cover cord made of steel or organic fiber material with coating rubber, and has a cord angle of 0 degrees or more and 10 degrees or less in absolute value. The belt cover 143 is, for example, a strip material formed by covering one or more belt cover cords with coating rubber, and is formed by winding this strip material spirally around the outer circumferential surfaces of the cross belts 141, 142 multiple times in the tire circumferential direction. The belt cover 143 is disposed to cover the entire area of ​​the cross belts 141, 142.

[0018] The tread rubber 15 is disposed on the outer periphery of the carcass layer 13 and the belt layer 14 in the tire radial direction to form the tread portion of the tire 1. The tread rubber 15 is made of a rubber material with excellent ground contact characteristics and weather resistance, and is exposed over the entire outer periphery of the tire to form the tread surface. A pair of sidewall rubbers 16, 16 are disposed on the outer sides of the carcass layer 13 in the tire width direction to form left and right sidewall portions. A pair of rim cushion rubbers 17, 17 extend from the inner side in the tire radial direction of the left and right bead cores 11, 11 and the turned-up portions of the carcass layer 13 to the outer side in the tire width direction to form the rim fitting surface of the bead portion.

[0019] [Tire Side Portion] Fig. 2 is a plan view showing the tire side portion of the tire shown in Fig. 1. Fig. 3 is an enlarged view showing the marking portion 2 of the tire side portion shown in Fig. 2. In these figures, Fig. 2 shows a plan view of the tire 1 as seen from the axial direction, and Fig. 3 shows a part of the marking portion 2.

[0020] As shown in FIG. 2, the tire 1 includes a marking portion 2 and a peripheral region 3 on the tire side.

[0021] The marking portion 2 includes a mark consisting of letters, figures, symbols, or a combination thereof, and particularly includes a trademark that functions as an identification sign indicating the tire manufacturer, tire brand, etc. Furthermore, multiple marking portions 2, 2 are arranged spaced apart in the tire circumferential direction. For example, in the configuration shown in Fig. 2, a mark consisting of a combination of the character string "YOKOHAMA" indicating the tire manufacturer and a logo with a stylized "Y," the initial letter of the name, is stamped on the surface of the tire side. Furthermore, a pair of marking portions 2, 2 are arranged in opposing positions in the tire circumferential direction.

[0022] 3, the radial height H2 of the elements 2A to 2E constituting the marking portion 2 is in the range of 0.05≦H2 / SH≦0.80 relative to the tire cross-sectional height SH, and preferably in the range of 0.10≦H2 / SH≦0.70. This improves the visibility of the marking portion 2.

[0023] The radial height H2 of the elements 2A to 2E is measured as the maximum extension length of the elements 2A to 2E in the tire radial direction.

[0024] The tire section height SH is the distance half the difference between the tire outer diameter and the rim diameter, and is measured with the tire mounted on a specified rim, with a specified internal pressure applied, and in an unloaded state.

[0025] The specified rim refers to the "applicable rim" specified by JATMA, the "design rim" specified by TRA, or the "measuring rim" specified by ETRTO. The specified internal pressure refers to the "maximum air pressure" specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" specified by TRA, or the "inflation pressures" specified by ETRTO. The specified load refers to the "maximum load capacity" specified by JATMA, the maximum value of the "tire load limits at various cold inflation pressures" specified by TRA, or the "load capacity" specified by ETRTO. However, in JATMA, for passenger car tires, the specified internal pressure is 180 kPa, and the specified load is 88% of the maximum load capacity.

[0026] The peripheral region 3 is an area surrounding the marking portion 2 and is formed on the surface of the tire side portion. The peripheral region 3 may be a smooth surface having a smooth surface, or may be an uneven surface that has been subjected to a surface treatment.

[0027] For example, in the configuration of Fig. 2, the peripheral region 3 is a smooth, continuous, smooth surface without grooves or unevenness. The peripheral region 3 is disposed to surround the entire marking portion 2, thereby enhancing the visibility of the marking portion 2. The peripheral region 3 is formed between a pair of narrow ribs 41, 42 extending in the tire circumferential direction, thereby enhancing the design of the tire side portion. The single peripheral region 3 has an annular structure extending around the entire circumference of the tire side portion, thereby surrounding the pair of marking portions 2, 2.

[0028] 2 , the marking portion 2 and the peripheral region 3 are disposed radially outward of the tire maximum width position Ac. More specifically, a pair of narrow ribs 41, 42 extending in the tire circumferential direction are disposed in the region from the tire ground contact edge T to the tire maximum width position Ac (see FIG. 1 ), and the marking portion 2 and the peripheral region 3 are disposed between these narrow ribs 41, 42. This improves the visibility of the marking portion 2. However, this is not limiting, and the marking portion 2 and the peripheral region 3 may be disposed so as to intersect with the tire maximum width position Ac or may be disposed radially inward of the tire maximum width position Ac (not shown).

[0029] The tire maximum width position Ac is defined as the maximum width position of the tire section width.

[0030] The tire cross-sectional width is measured as the straight-line distance between the sidewalls, excluding any patterns or letters on the side of the tire, when the tire is mounted on a specified rim, pressurized to a specified internal pressure, and under no load.

[0031] The tire ground contact edge T is defined as the widest position in the axial direction of the tire at the contact surface between the tire and a flat plate when the tire is mounted on a specified rim, pressurized to a specified internal pressure, and placed perpendicular to a flat plate in a stationary state and subjected to a load corresponding to a specified load.

[0032] The pair of thin ribs 41, 42 have a width of 0.4 mm to 0.8 mm and a height of 0.1 mm to 1.0 mm, and function as a path for discharging residual air during tire vulcanization. This prevents vulcanization defects from occurring in the marking portion 2 and the surrounding area 3. In the configuration shown in Figure 2, the thin rib 41 on the outer diameter side is located at the mold split position of the tire molding die.

[0033] 3, the radial height H2 [mm] of the elements 2A to 2E constituting the marking portion 2, relative to the arrangement interval H4 [mm] of the thin ribs 41, 42 in the tire radial direction, is in the range of 0.30≦H2 / H4≦0.80, and preferably in the range of 0.40≦H2 / H4≦0.70. Also, as shown in FIG. 3, it is preferable that the marking portion 2 is arranged at a distance from the pair of thin ribs 41, 42. This improves the visibility of the marking portion 2.

[0034] [Ridge of Marking Portion] Figures 4 to 6 are explanatory diagrams showing the marking portion 2 in the tire side portion shown in Figure 2. In these figures, Figure 4 shows one element 2A constituting the marking portion 2, Figure 5 is an enlarged perspective view showing a part of the marking portion 2 shown in Figure 4, and Figure 6 is a cross-sectional view taken along line A showing the marking portion 2 shown in Figure 5.

[0035] 4 to 6, the mark portion 2 is made up of a housing 21 and a plurality of ridges 22. Here, as an example, a logo 2A that constitutes the mark portion 2 will be described.

[0036] The housing 21 is a frame-shaped recess formed in the tire side surface, and in a plan view of the tire side, forms the outline of the marking portion 2. The depth H21 of the housing 21 (see FIG. 6) is in the range of 0.10 mm≦H21≦3.00 mm, and preferably in the range of 0.20 mm≦H21≦1.50 mm.

[0037] The depth H21 of the housing 21 is defined as the distance from the edge of the housing 21 (in Figure 6, the surface of the peripheral region 3 surrounding the marking portion 2) to the bottom surface of the housing 21, and specifically, is measured as the distance from the edge of the housing 21 to the bottom of the valley between adjacent ridges 22, 22.

[0038] 5, the ridge 22 is a rib-like convex portion protruding from the bottom surface of the housing 21, and has a cross-sectional shape with a width W22A (see FIG. 6) that narrows toward the top. A plurality of ridges 22 are arranged in parallel in a predetermined direction and filled into the housing 21.

[0039] For example, in the configuration of Fig. 2, as shown in Fig. 4, the logo 2A constituting the marking portion 2 is made up of a combination of multiple thin lines arranged in parallel, and as shown in Fig. 5, the outlines of these thin lines are formed by the edge portions of the housing 21. Similarly, other components constituting the marking portion 2 (for example, elements 2B to 2E in Fig. 3) are made up of thick lines representing letters, and the outlines of the thick lines are formed by the edge portions of the housing 21 (not shown).

[0040] 5, the plurality of ridges 22 have a straight shape with a uniform trapezoidal or triangular cross section. These ridges 22 are aligned longitudinally in one direction and fill the entire area of ​​the housing 21. Both ends of the ridges 22 are connected to the wall surfaces of the housing 21. As a result, the mark of the marking portion 2 is expressed by the housing 21 and the plurality of ridges 22.

[0041] In the above configuration, the marking portion 2 is made up of a plurality of ridges 22 arranged inside the housing 21, so that (1) in a plan view of the tire side portion, the light absorption rate in the marking portion 2 is relatively higher than the light absorption rate in the peripheral region 3. This makes the marking portion 2 relatively black, improving the visibility of the marking portion 2. In addition, (2) since the wax applied to the marking portion 2 is held by the plurality of ridges 22, the wax retention in the marking portion 2 is improved.

[0042] 6 , the height H22 of the ridge 22 is in the range of 1.00≦H22 / H21 relative to the depth H21 of the housing 21. Therefore, the top of the ridge 22 is exposed on the surface of the peripheral region 3 without being buried in the housing 21. This makes it easier to apply wax to the top of the ridge 22, further improving wax retention in the marking portion 2. Furthermore, the height H22 of the ridge 22 is in the range of 0 mm≦H22−H21≦3.50 mm, preferably 0.10 mm≦H22−H21≦1.50 mm, and more preferably 0.20 mm≦H22−H21≦1.00 mm, relative to the depth H21 of the housing 21. The lower limit ensures wax retention in the marking portion 2, while the upper limit prevents deterioration of air resistance in the tire sidewall due to an excessively large ridge height H22.

[0043] The height H22 of the ridge 22 is defined as the distance from the top of the ridge 22 to the bottom surface of the housing 21, as shown in Figure 6, and specifically, is measured as the distance from the top of the ridge 22 to the bottom of the valley between adjacent ridges 22, 22.

[0044] 6, the pitch length P22 of the ridges 22 is in the range of 0.05 mm≦P22≦0.50 mm, and preferably in the range of 0.05 mm≦P22≦0.30 mm. Therefore, the ridges 22 are densely arranged. This improves the blackening effect of the ridges 22 on the marking portion 2.

[0045] 6, the width W22A of the top of the ridge 22, relative to the width W22B of the base of the ridge 22, is in the range of 0≦W22A / W22B≦0.90, preferably 0.10≦W22A / W22B≦0.70. The lower limit prevents deterioration in the processability of the marking portion 2 caused by the top of the ridge 22 being too thin, while the upper limit improves the blackening effect of the ridge 22 on the marking portion 2. The width W22B of the base of the ridge 22, relative to the pitch length P22 of the multiple ridges 22, is in the range of 0.05≦W22B / P22≦0.80, preferably 0.05≦W22B / P22≦0.50.

[0046] The widths W22A and W22B of the ridges 22 are measured as widths in a cross section perpendicular to the longitudinal direction of the ridges 22. The width W22B of the base of the ridges 22 is defined as the width of the contact area between the ridges 22 and the bottom surface of the housing 21, and is specifically measured as the distance between imaginary lines connecting the valley bottoms of adjacent ridges 22, 22.

[0047] 7 to 9 are explanatory diagrams showing modified examples of the tire 1 shown in Fig. 6. In these figures, the same components as those shown in Fig. 6 are denoted by the same reference numerals, and the description thereof will be omitted.

[0048] 6, the ridges 22 each have a trapezoidal cross section when viewed perpendicular to the longitudinal direction. This means that the tops of the ridges 22 have wide top surfaces. This configuration is preferable because the ridges 22 can be easily processed.

[0049] 7, the ridges 22 each have a triangular cross section when viewed perpendicular to the longitudinal direction. As a result, the apex of the ridge 22 has a very narrow width W22A. This configuration is preferable in that the ridges 22 improve the blackening effect of the marking portion 2.

[0050] 6, the tops of the ridges 22 protrude outside the housing 21. Therefore, the height H22 of the ridges 22 is in the range of 0 mm < H22 - H21 relative to the depth H21 of the housing 21. This configuration is preferable because it enhances the wax retention effect of the ridges 22.

[0051] 8, the height H22 of the ridge 22 is set so that the top surface of the ridge 22 is flush with the surface of the peripheral region 3. Therefore, the height H22 of the ridge 22 has a relationship of H22-H21=0 [mm] with respect to the depth H21 of the housing 21. Even with this configuration, the wax retention effect of the ridge 22 is enhanced compared to a configuration in which the top of the ridge 22 is buried within the housing 21 (H22-H21<0 [mm]).

[0052] 6, the peripheral area 3 is a smooth surface, which is preferable in that the visibility of the marking portion 2 consisting of the housing 21 and the plurality of ridges 22 is improved.

[0053] However, the present invention is not limited to this, and the peripheral region 3 may have a textured surface as shown in Fig. 9. The textured surface may be formed by arranging a plurality of uneven portions, for example, a plurality of longitudinal ridges or grooves, or a plurality of hemispherical or conical protrusions or depressions (not shown). This improves the retention of wax in the symbol portion 2 and the peripheral region 3.

[0054] 9 , the uneven surface of the peripheral region 3 is formed by an arrangement of multiple uneven portions 31, 32. Furthermore, the pitch length P3 of the multiple uneven portions 31, 32, relative to the pitch length P22 of the multiple ridges 22 constituting the marking portion 2, is within the range of 0.20≦P3 / P22≦5.00, and preferably within the range of 0.30≦P3 / P22≦3.00. Furthermore, the height H3 of the multiple uneven portions 31, 32, relative to the height H22 of the multiple ridges 22 constituting the marking portion 2, is within the range of 0.30≦H3 / H22≦1.00, and preferably within the range of 0.50≦H3 / H22≦0.80. Therefore, the pitch length P3 of the multiple uneven portions 31, 32 is shorter than the pitch length P22 of the multiple ridges 22 constituting the marking portion 2. Furthermore, the height H3 of the multiple uneven portions 31, 32 is smaller than the height H22 of the multiple ridges 22 constituting the marking portion 2. This improves the visibility of the marking portion 2.

[0055] [Applicable Objects] In this embodiment, as described above, a pneumatic tire has been described as an example of a tire. However, the present invention is not limited to this, and the configuration described in this embodiment can be applied to other tires as desired within the scope of what is obvious to those skilled in the art. Examples of other tires include airless tires and solid tires.

[0056] [Effects] As described above, [1] the tire 1 includes a marking portion 2 formed on the tire side surface (see FIGS. 1 and 2). The marking portion 2 is composed of a housing 21 formed on the tire side surface and a plurality of ridges 22 that protrude from the bottom surface of the housing 21 and are arranged in parallel in a predetermined direction (see FIGS. 5 and 6). The height H22 of the ridges 22, relative to the depth H21 of the housing 21, is in the range of 1.00≦H22 / H21 (see FIG. 6). The pitch length P22 of the plurality of ridges 22 is in the range of 0.05 mm≦P22≦0.50 mm.

[0057] In this configuration, (1) since the marking portion 2 is made up of a plurality of ridges 22 arranged within the housing 21, the marking portion 2 is blackened in a plan view of the tire sidewall, improving the visibility of the marking portion 2 and also improving the retention of wax applied to the marking portion 2. Also, (2) since the height H22 of the ridges 22 is within the above range relative to the depth H21 of the housing 21, wax is easily applied to the tops of the ridges 22, further improving the retention of wax in the marking portion 2. Furthermore, (3) since the pitch length P22 of the plurality of ridges 22 is within the above range, the blackening effect of the ridges 22 on the marking portion 2 is improved. These advantages result in improved visibility of the marking portion 2 and improved wax retention.

[0058] [2] In the tire 1 described in [1] above, the height H22 of the ridge 22 is in the range of 0 mm≦H22−H21≦3.50 mm relative to the depth H21 of the housing 21 (see FIG. 6 ). The lower limit ensures wax retention in the marking portion 2, while the upper limit has the advantage of suppressing deterioration of air resistance in the tire sidewalls due to an excessively large ridge height H22.

[0059] [3] In the tire 1 described in [2] above, the height H22 (see FIG. 6) of the ridge 22 is in the range of 0.10 mm≦H22−H21 relative to the depth H21 of the housing 21. This configuration has the advantage that the ridge 22 of the marking portion 2 protrudes outward from the housing 21, thereby improving the retention of wax in the marking portion 2.

[0060] [4] In addition, in the tire 1 according to any one of the above items [1] to [3], the depth H21 (see FIG. 6) of the housing 21 is in the range of 0.10 mm≦H21≦3.00 mm. The lower limit ensures the depth H21 of the housing 21, thereby ensuring the effects of improving the visibility and wax retention of the marking portion 2, while the upper limit has the advantage of suppressing deterioration in the processability of the marking portion 2 caused by the depth H21 of the housing 21 being too deep.

[0061] [5] In addition, in the tire 1 according to any one of the above [1] to [4], the width W22A of the top of the ridge 22 is in the range of 0 < W22A / W22B ≦ 0.90 relative to the width W22B of the base of the ridge 22 (see FIG. 6 ). The lower limit prevents deterioration in the processability of the marking portion 2 caused by the ridge 22 being too thin, and the upper limit improves the blackening effect of the marking portion 2 by the ridge 22.

[0062] [6] In addition, in the tire 1 according to any one of the above [1] to [5], the peripheral region 3 surrounding the marking portion 2 is a smooth surface (see FIGS. 2 and 3), which has the advantage of improving the visibility of the marking portion 2.

[0063] [7] In the tire 1 according to any one of the above [1] to [5], the peripheral region 3 surrounding the marking portion 2 is an uneven surface having a surface treatment (see FIG. 9 ). This has the advantage of improving wax retention in the marking portion 2 and the peripheral region 3.

[0064] [8] In the tire 1 described in [7] above, the uneven surface of the peripheral region 3 of the tire 1 is formed by arranging a plurality of uneven portions 31, 32 (see FIG. 9). Furthermore, the pitch length P3 of the plurality of uneven portions 31, 32 is shorter than the pitch length P22 of the plurality of ridges 22 that form the marking portion 2 (P3<P22). This has the advantage of improving the visibility of the marking portion 2 in the peripheral region 3.

[0065] [9] In the tire 1 according to the above [7] or [8], the uneven surface of the peripheral region 3 is formed by arranging a plurality of uneven portions 31, 32 (see FIG. 9). Also, a height P3 of the plurality of uneven portions 31, 32 is smaller than a height H22 of the plurality of ridges 22 that constitute the marking portion 2 (H3<H22). This has the advantage of improving the visibility of the marking portion 2 in the peripheral region 3.

[0066] FIG. 10 is a table showing the results of performance tests on the tire according to the embodiment of the present invention.

[0067] In this performance test, several types of test tires were evaluated for (1) visibility of the markings and (2) wax retention. Test tires with a tire size of 235 / 50R18 were mounted on rims with a rim size of 18x7½J, and an internal pressure of 230 kPa was applied to the test tires.

[0068] (1) In the evaluation of the visibility of the markings, an inspector visually inspects the tire side of the test tire from a distance of 5 m and performs a sensory evaluation of the visibility of the markings, particularly the degree of blackening of the markings. This evaluation is performed using an index evaluation with the comparative example as the standard (100), and the larger the value, the better.

[0069] (2) To evaluate wax retention, a water-based tire wax containing red coloring was applied to the sidewall of the test tire, and the test tire was exposed to an outdoor exposure test site. After one month, an inspector visually evaluated the amount of wax remaining on the marking area. This evaluation was performed using an index based on the comparative example (100), with the higher the index value, the better.

[0070] 1 and 2, and the marking portion 2 is composed of a housing 21 and a plurality of ridges 22 (see FIGS. 5 and 6). The peripheral region 3 surrounding the marking portion 2 is composed of a smooth surface, and the marking portion 2 and the peripheral region 3 are disposed between a pair of thin ribs 41, 42. The radial height H2 [mm] of the marking portion 2 is 18 [mm], and the spacing H4 [mm] between the thin ribs 41, 42 is 25.5 [mm].

[0071] As the test results show, the test tires of the examples have improved visibility of the markings and wax retention.

[0072] 1 tire; 11 bead core; 12 bead filler; 13 carcass layer; 14 belt layer; 141, 142 cross belt; 143 belt cover; 15 tread rubber; 16 sidewall rubber; 17 rim cushion rubber; 20 rim; 2 marking portion; 21 housing; 22 ridge; 3 peripheral region; 31 uneven portion; 41, 42 narrow rib

Claims

1. A tire having a logo portion formed on a tire side surface, wherein the logo portion comprises a housing formed on the tire side surface and a plurality of ridges protruding from the bottom surface of the housing and arranged in parallel in a predetermined direction, the height H22 of the ridge is in the range of 1.00 ≦ H22 / H21 with respect to the depth H21 of the housing, and the pitch length P22 of the plurality of ridges is in the range of 0.05 [mm] ≦ P22 ≦ 0.50 [mm].

2. The tire according to claim 1, wherein the height H22 of the ridge is in the range of 0 [mm] ≦ H22 - H21 ≦ 3.50 [mm] with respect to the depth H21 of the housing.

3. The tire according to claim 2, wherein the height H22 of the ridge is in the range of 0.10 [mm] ≦ H22 - H21 with respect to the depth H21 of the housing.

4. The tire according to any one of claims 1 to 3, wherein the depth H21 of the housing is in the range of 0.10 [mm] ≦ H21 ≦ 3.00 [mm].

5. The tire according to any one of claims 1 to 4, wherein the width W22A of the top of the ridge is in the range of 0 < W22A / W22B ≦ 0.90 with respect to the width W22B of the base of the ridge.

6. The tire according to any one of claims 1 to 5, wherein the peripheral region surrounding the logo portion is a smooth surface having a smooth surface.

7. The tire according to any one of claims 1 to 5, wherein the peripheral region surrounding the logo portion is a concavo-convex surface having a surface treatment.

8. The tire according to claim 7, wherein the concavo-convex surface of the peripheral region is formed by arranging a plurality of concavo-convex portions, and the pitch length P3 of the plurality of concavo-convex portions is shorter than the pitch length P22 of the plurality of ridges constituting the logo portion.

9. The tire according to claim 7 or 8, wherein the concavo-convex surface of the peripheral region is formed by arranging a plurality of concavo-convex portions, and the height P3 of the plurality of concavo-convex portions is smaller than the height H22 of the plurality of ridges constituting the logo portion.

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