Tire

Abstract

To provide a tire in which a plurality of display articles are arranged on an outer surface of a side wall part, which is manufactured through a step of polishing surfaces of the display articles, and whose outer appearance can be made good by polishing the surfaces of the plurality of display articles so that heights of the surfaces are equalized.SOLUTION: In a tire, a plurality of display articles 10 are arranged on an outer surface of a side wall part 2, where at least portions of top surfaces of convex parts 11 constituting outlines of characters, graphics or signs described by the display articles 10 have a color different from a color of the outer surface of the side wall part 2 by exposing a different-colored rubber buried in a portion of the side wall part 2. When a group of a series of the display articles 10 arranged adjacently in a tire circumferential direction is defined as a character row 20 and the display articles 10 positioned at both ends in the tire circumferential direction of the character row are defined as end characters 21, inclination angles Y1 of wall surfaces of outer parts in the tire circumferential direction of the end characters 21 are set to be 5°-10°and the inclination angles Y1 are set to be smaller than an inclination angle Y2 of a wall surface of the other part of the same character row 20.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a tire having indicia depicting letters, figures, or symbols on the outer surface of the sidewall portion. [Background technology]

[0002] Indicia for displaying the manufacturer's name, brand name, etc., may be formed on the outer surface of the sidewall of a tire. In particular, in order to improve the visibility and decorativeness of these indicators, they are formed using a different-colored rubber (e.g., white rubber) that is a different color from the color of the sidewall (generally black) (so-called "white letters"). When manufacturing such tires, at least a portion of the portion corresponding to the sidewall of a green tire (the portion corresponding to the indicator) is formed into a laminated structure of a different-colored rubber layer (white rubber layer) and a cover rubber layer (black rubber layer) that covers the different-colored rubber layer, the green tire is vulcanized, and the indicators are formed as protrusions protruding from the surface of the sidewall. The surface of the protrusions (cover rubber layer) is then polished and removed to expose the white rubber layer, thereby forming the indicators made of different-colored rubber (see, for example, Patent Document 1).

[0003] In such tires, the process of polishing the surface of the indicia (protrusions) is carried out using a dedicated polishing machine (buffing machine) or the like. This machine rotates a polishing body (such as a grindstone) against the side of the tire, which is mounted on a stand and rotates, and polishes the tire's sidewall (indicia) in the thickness direction (the direction of the protrusion height of the protrusions) at intervals preset for each type of tire, polishing so as to expose the embedded rubber of a different color on the tire surface (see, for example, Patent Document 2). When performing the polishing process (buffing process) with such a machine, it is difficult to uniformly polish the amount of polishing (protrusion height) of each indicia included in the string, particularly when polishing (buffing) a string of characters consisting of multiple indicia, which can result in a deterioration in the appearance of the indicia (character string) after polishing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-114732 [Patent Document 2] Japanese Patent Application Publication No. 05-277925 Summary of the Invention [Problem to be solved by the invention]

[0005] The object of the present invention is to provide a tire that has a plurality of markings depicting letters, figures, or symbols on the outer surface of the sidewall portion and is manufactured through a process of polishing the surface of these markings, in which the raised height of the plurality of markings after polishing is made uniform, thereby making it possible to improve the appearance of the tire. [Means for solving the problem]

[0006] In order to achieve the above object, a first tire of the present invention comprises a tread portion extending circumferentially in an annular shape and a pair of sidewall portions disposed on either side of the tread portion, and a plurality of indicia depicting letters, figures, or symbols are formed on the outer surface of the sidewall portion by the shape of the top surfaces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top surfaces of the protrusions constituting each of the plurality of indicia have a different color from the outer surface of the sidewall portion by exposing different-colored rubber embedded in a portion of the sidewall portion. In this tire, when a group of the plurality of indicia objects in which the circumferential spacing between adjacent indicia objects is less than 20 mm is defined as a character string, and a pair of indicia objects located at both ends of the character string in the circumferential direction of the tire is defined as an end character, the inclination angle Y1 formed by the wall surface of the circumferential outer portion of the end character with respect to the normal to the top surface of the end character is in the range of 5° to 10°, and the inclination angle Y1 is smaller than the inclination angle Y2 formed by the wall surfaces of other portions of indicia objects included in the same character string as the end character with respect to the normal to the top surface of each indicia object.

[0007] A second tire of the present invention for achieving the above object comprises a tread portion extending in the circumferential direction of the tire to form an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, and a plurality of indicia depicting letters, figures or symbols are formed on the outer surface of the sidewall portion by the shapes of the top faces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top face of the protrusions constituting each of the plurality of indicia has a color different from that of the outer surface of the sidewall portion by exposing a different color rubber embedded in a portion of the sidewall portion, in the tire, in which adjacent indicia among the plurality of indicia are different from each other. When a group of markings with a circumferential spacing of less than 20 mm is defined as a character string, and a pair of markings located at both ends of the character string in the tire circumferential direction are defined as terminal characters, the wall surface of the circumferentially outer part of the terminal character is smoothly connected to the outer surface of the sidewall portion via an arc-shaped connecting portion, and the radius of curvature R1 of the connecting portion at the circumferentially outer part of the terminal character is in the range of 1 mm to 2 mm, and the wall surfaces of other parts of the markings included in the same character string as the terminal character are smoothly connected to the outer surface of the sidewall portion via an arc-shaped connecting portion, and the radius of curvature R1 is smaller than the radius of curvature R2 of the connecting portion at the wall surface of the other parts. [Effects of the Invention]

[0008] The inventors have conducted extensive research into the appearance defects of markings in tires manufactured through a process of polishing the surfaces of the convex portions that make up the markings, and have found that when the object to be polished is a string of markings consisting of multiple markings, the first and last markings that the polishing body comes into contact with are likely to be subjected to a load from the polishing body, resulting in a tendency for portions of the end characters to be excessively polished (buffed). More specifically, when the polishing body begins to come into contact with the end character (or when it moves away from the end character), there is a moment when the polishing body comes into contact with only a portion of the end character (the outer portion in the tire circumferential direction), so the load of the polishing body on that portion becomes large, and portions of the end character (particularly the outer portion in the tire circumferential direction) are excessively polished (buffed) (note that other portions of the string of markings are polished (buffed) almost evenly because the polishing body comes into contact with the entire individual markings and the entirety of the polishing body straddling adjacent markings). The present invention is based on this finding, and by reducing the rigidity of the circumferentially outer portion of the terminal character, the load of the polishing body on that portion is distributed and excessive polishing (buffing) of that portion is suppressed, thereby making the raised height of the marking object uniform after polishing and improving its appearance. In the first tire of the present invention, the rigidity of the circumferentially outer portion of the terminal character is reduced by setting the inclination angle Y1 of the wall surface of the terminal character at 5° to 10° as described above and making the inclination angle Y1 smaller than the inclination angle Y2 of the wall surface of other portions of the marking object included in the same character string as the terminal character. In the second tire of the present invention, the rigidity of the circumferentially outer portion of the terminal character is reduced by setting the curvature radius R1 of the connecting portion of the terminal character at the circumferentially outer portion of the terminal character in the range of 1 mm to 2 mm as described above and making the curvature radius R1 smaller than the curvature radius R2 of the connecting portion of other portions of the marking object included in the same character string as the terminal character.

[0009] In this invention, for the sake of convenience, a group of a series of multiple indicia elements in which the circumferential spacing between adjacent indicia elements is less than 20 mm is defined as a "character string." However, since indicia elements depict characters, figures, or symbols, any group of characters, figures, symbols, or a group of indicia elements that combine these elements also falls under the category of a "character string." Similarly, regardless of whether the indicia elements are characters, figures, or symbols, those located at both ends of a "character string" in the circumferential direction of the tire fall under the category of an "end character."

[0010] In the first tire of the present invention, the inclination angle Y2 is preferably in the range of 10° to 20°. This provides a good balance between the inclination angles Y1 and Y2 of the wall surfaces of the outer portion of the final character in the tire circumferential direction and the wall surfaces of other portions of the indicia included in the same character string as the final character, which is advantageous for improving the appearance of the indicia after polishing.

[0011] In the second tire of the present invention, the radius of curvature R2 is preferably in the range of 2 mm to 3 mm, which provides a good balance between the radii of curvature R1 and R2 at the connecting portion of the end character on the outer side in the tire circumferential direction and the connecting portion of other portions of the indicia included in the same character string as the end character, which is advantageous for improving the appearance of the indicia after polishing.

[0012] In the tire of the present invention, when the angle formed by a pair of tangents drawn from the tire rotation axis to both circumferential ends of the terminal character is defined as the character width X (unit: °) of the terminal character, the outer circumferential portion of the terminal character is preferably a portion in the tire circumferential direction that is further outward in the tire direction than a position 0.25 to 0.75 times the character width X from the outer circumferential end of the terminal character in this way. By specifying the range of the outer circumferential portion of the terminal character in the tire direction (i.e., the portion that is likely to be subjected to excessive load from the polishing body), it is possible to more effectively achieve the effects of setting the above-mentioned inclination angles Y1, Y2 and radii of curvature R1, R2, which is advantageous for improving the appearance of the displayed object after polishing.

[0013] In the tire of the present invention, when a pair of tangents is drawn from the tire rotation axis to both circumferential ends of the terminal character, the distance between the pair of tangents at the tire radial center of the terminal character is preferably 20 mm or more. If the distance between the pair of tangents at the tire radial center of the terminal character (i.e., the character width of the terminal character) is large in this way, the grinding body is likely to contact only a part of the terminal character (the outer part in the tire circumferential direction) when it begins to contact the terminal character (or when it moves away from the terminal character), so by setting the above-mentioned inclination angles Y1, Y2 and curvature radii R1, R2 in such a tire, the effects of the present invention can be more effectively achieved. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a meridian cross-sectional view of a pneumatic tire according to an embodiment of the present invention. [Figure 2] 1A and 1B are explanatory diagrams schematically showing the state of a display object before and after polishing. [Figure 3] 1 is a schematic diagram showing an example of a display object (character string) according to an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view schematically showing a display object according to an embodiment of the present invention. [Figure 5] FIG. 10 is a cross-sectional view schematically showing a display object according to another embodiment of the present invention. [Figure 6] 1A and 1B are schematic diagrams illustrating the character width and the like of the display of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The configuration of the present invention will be described in detail below with reference to the accompanying drawings.

[0016] When the tire of the present invention is a pneumatic tire as shown in FIG. 1 , it comprises a tread portion 1 that contacts the road surface, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3 arranged radially inward of the sidewall portions 2. In FIG. 1 , the symbol CL denotes the tire equator, and the symbol E denotes the ground-contact edge. Although not depicted in FIG. 1 because it is a meridian cross-section, the tread portion 1, sidewall portions 2, and bead portions 3 each extend in the tire circumferential direction and form an annular shape, thereby constituting the basic toroidal structure of a pneumatic tire. The following explanation using FIG. 1 is basically based on the meridian cross-section shape shown, but each tire component extends in the tire circumferential direction and forms an annular shape.

[0017] A carcass layer 4 is installed between a pair of left and right bead portions 3. The carcass layer 4 includes a plurality of reinforcing cords extending in the tire radial direction and folded back from the inner side to the outer side in the tire width direction around a bead core 5 arranged in each bead portion 3. A bead filler 6 is arranged on the outer periphery of the bead core 5, and this bead filler 6 is wrapped by the main portion and folded back portion of the carcass layer 4. Meanwhile, a plurality of belt layers 7 (two layers in FIG. 1 ) are embedded on the outer periphery of the carcass layer 4 in the tread portion 1. Each belt layer 7 includes a plurality of reinforcing cords inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged so as to cross each other between the layers. In these belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set, for example, in the range of 10° to 40°. Furthermore, at least one belt reinforcing layer 8 (two layers in FIG. 1 ) is provided on the outer periphery of the belt layer 7. The belt reinforcing layer 8 includes organic fiber cords oriented in the tire circumferential direction. In the belt reinforcing layer 8, the organic fiber cords are set at an angle of, for example, 0° to 5° with respect to the tire circumferential direction.

[0018] As described below, the present invention relates to indicia formed on the surface of the tire sidewall portion 2, and therefore the basic structure (cross-sectional structure) of the tire is not limited to the general structure described above. Furthermore, the following description will be based on a pneumatic tire (a tire filled with air, an inert gas such as nitrogen, or other gases) as shown in Fig. 1 etc., but the present invention can be applied to various tires, including non-pneumatic tires, as long as the tire has indicia depicting letters, figures, or symbols on the outer surface of the sidewall portion and is manufactured through a process of polishing the surface of the indicia.

[0019] In the present invention, as shown in Figure 1, a display 10 is provided on the outer surface of at least one of the pair of sidewall portions 2. The display 10 depicts letters, figures, or symbols using the shape of the top surfaces of protrusions 11 that protrude from the outer surfaces of the sidewall portions 2. The display 10 of the present invention has a different color from the outer surfaces of the sidewall portions by exposing different-colored rubber 12 embedded in part of the sidewall portions 2 at least in part of the top surfaces of the protrusions 11 that make up the display 10. Since the outer surfaces of tire sidewall portions are generally black, it is preferable that the different-colored rubber be white rubber from the standpoints of visibility and decorativeness.

[0020] More specifically, the protrusion 11 constituting the marker 10 is formed as a laminate of different-colored rubber 12 embedded in the sidewall portion 2 and a cover rubber 13 covering the different-colored rubber 12, as shown in FIG. 2(a). Then, by polishing and removing the surface of this protrusion 11 (the cover rubber 13 and a part of the different-colored rubber 12), the different-colored rubber 12 is exposed as shown in FIG. 2(b), and the marker 10 is formed with at least a part of the top surface of the marker 10 being made of the different-colored rubber 12. Note that FIG. 2(b) shows the state where the area above the dashed line in FIG. 2(a) has been polished and removed. Because it is manufactured as described above, strictly speaking, the top surface of the protrusion 11 of the present invention is made of the different-colored rubber 12 except for the peripheral portion derived from the cover rubber 13.

[0021] In the present invention, as shown in FIG. 3 , a plurality of the above-described display objects 10 are provided, and these plurality of display objects 10 constitute a character string 20. More specifically, the character string 20 is a group of a series of display objects 10, among the plurality of display objects 10, in which the circumferential distance between adjacent display objects 10 is less than 20 mm. In the illustrated example, a character string 20 consisting of 10 circles and a character string 20 consisting of four triangles are provided. Note that, since the distance between the former and latter (the circumferential distance between the display object 10 furthest from the back of the display objects 10 included in the former character string 20 and the display object 10 furthest from the front of the display objects 10 included in the latter character string 20) is 20 mm or more, the former and latter are interpreted as separate character strings 20. In addition, in such a character string 20, a pair of display objects 10 located at both ends in the tire circumferential direction (the display objects 10 hatched in FIG. 3 ) are defined as end characters 21 in the present invention.

[0022] In a first aspect of the present invention, as shown in Fig. 4, the inclination angle Y1 formed by the tire circumferentially outer portion of the final character 21 with respect to the normal to the top surface 21b of the final character 21 is set to 5° to 10°, preferably 5° to 7°. The inclination angle Y1 is set to be smaller than the inclination angle Y2 formed by the wall surfaces 10a of other portions of the objects 10 included in the same character string 20 (objects 10 other than the final character 21 of the same character string 20 and portions other than the tire circumferentially outer portion of the final character 21) with respect to the normal to the top surface 10b of each object 10. The inclination angle Y2 is preferably 10° to 20°.

[0023] In a second embodiment of the present invention, as shown in Fig. 5, the wall surface 21a of the circumferentially outer portion of the final character 21 is smoothly connected to the outer surface of the sidewall portion 2 via an arc-shaped connecting portion 21c, and the curvature radius R1 of the connecting portion 21c at the circumferentially outer portion of the final character 21 is set to 1 mm to 2 mm, preferably 1 mm to 1.5 mm. Furthermore, the wall surfaces 10a of other portions of the indicia 10 included in the same character string 20 (i.e., portions of the indicia 10 other than the final character 21 of the same character string 20 and portions other than the circumferentially outer portion of the final character 21) are also smoothly connected to the outer surface of the sidewall portion 2 via arc-shaped connecting portions 10c, and the curvature radius R1 is set to be smaller than the curvature radius R2 of the connecting portions 10c at the wall surfaces of other portions. The curvature radius R2 is preferably 2 mm to 3 mm.

[0024] By setting the inclination angles Y1, Y2 and the curvature radii R1, R2 in this way, it is possible to reduce the rigidity of the circumferentially outer portions of the end character 21, which are prone to excessive polishing, and to distribute the load of the polishing body on those portions, thereby preventing those portions from being excessively polished (buffed). This makes it possible to make the raised height of the indicia 10 after polishing uniform within the character string 20, improving its appearance (the appearance of the character string 20 as a whole).

[0025] In this case, if the inclination angle Y1 is less than 5°, the rigidity of the terminal character 21 will be significantly reduced, and there is a risk that the durability of the display object 10 (terminal character 21) will not be sufficiently ensured. If the inclination angle Y1 is more than 10°, the rigidity will not be sufficiently reduced, making it difficult to properly achieve the above-mentioned effects. If the inclination angle Y1 is greater than the inclination angle Y2, the rigidity of the terminal character 21 will be high, contrary to the intention of the present invention, and the load on the terminal character 21 will not be able to be distributed. If the inclination angle Y2 is less than 10°, the difference in rigidity between the terminal character 21 and other parts will not be sufficiently ensured, and the effect of uniforming the height of the display object 10 after polishing will not be fully expected.

[0026] Similarly, if the radius of curvature R1 is less than 1 mm, the rigidity of the terminal letter 21 will be significantly reduced, and there is a risk that the durability of the display object 10 (terminal letter 21) will not be sufficiently ensured. If the radius of curvature R1 exceeds 2 mm, the rigidity of the terminal letter 21 will not be sufficiently reduced, making it difficult to properly achieve the above-mentioned effects. If the radius of curvature R1 is greater than the radius of curvature R2, the rigidity of the terminal letter 21 will be higher, contrary to the intention of the present invention, and the load on the terminal letter 21 will not be able to be distributed. If the radius of curvature R2 is less than 2 mm, the difference in rigidity between the terminal letter 21 and other parts will not be sufficiently ensured, and the effect of uniforming the height of the display object 10 after polishing will not be fully expected.

[0027] The above conditions for the inclination angles Y1 and Y2 and the curvature radii R1 and R2 may be satisfied simultaneously. That is, in the tire circumferentially outer portion of the terminal character 21, the inclination angle Y1 may be set to 5° to 10°, preferably 5° to 7°, and the curvature radius R1 may be set to 1 mm to 2 mm, preferably 1 mm to 1.5 mm, and further, the inclination angle Y1 may be set smaller than the inclination angle Y2, and the curvature radius R1 may be set smaller than the curvature radius R2. Combining conditions in this manner can more efficiently reduce the rigidity of the tire circumferentially outer portion of the terminal character 21, which is prone to excessive polishing, and is advantageous for suppressing excessive polishing (buffing) of that portion.

[0028] In the present invention, the area where the rigidity should be reduced is the circumferentially outer portion of the terminal character 21, where excessive polishing is likely to occur. As shown in Figure 6, when the angle formed by a pair of tangents drawn from the tire rotation axis to both circumferential ends of the terminal character 21 is defined as the character width X (unit: °) of the terminal character 21, the area is preferably 0.25 to 0.75 times the character width X from the outer end of the terminal character 21, and more preferably 0.5 to 0.75 times the character width X. By specifying the range of the circumferentially outer portion of the terminal character 21 (i.e., the area where excessive load is likely to be applied to the polishing body), the effects of setting the inclination angles Y1 and Y2 and the radii of curvature R1 and R2 can be more effectively achieved, which is advantageous for improving the appearance of the display object 10 after polishing. If the circumferentially outer portion of the terminal character 21 (the portion where the inclination angle Y1 and the curvature radius R1 are set within the above ranges) is smaller than the above ranges, it is not possible to sufficiently distribute the load on the terminal character 21. If the circumferentially outer portion of the terminal character 21 (the portion where the inclination angle Y1 and the curvature radius R1 are set within the above ranges) is larger than the above ranges, the inclination angle Y1 and the curvature radius R1 of almost the entire terminal character 21 will be small, which may make it difficult to ensure sufficient rigidity of the terminal character 21.

[0029] According to the findings of the inventors of the present invention, when the grinding body begins to contact the terminal character (or when it moves away from the terminal character), the grinding body tends to contact only a portion of the terminal character 21 (the outer portion in the tire circumferential direction), which results in excessive grinding of that portion of the terminal character 21 (the outer portion in the tire circumferential direction).From this perspective, the wider the character width of the terminal character 21, the more likely it is that the grinding body will contact only a portion of the terminal character 21 (the outer portion in the tire circumferential direction), and the present invention is effective when applied to such tires.In other words, as shown in Figure 6, when a pair of tangents is drawn from the tire rotation axis to both circumferential ends of the terminal character 21, it is preferable that the distance W between the pair of tangents at the tire radial center position of the terminal character 21 be 20 mm or more. If the distance between the pair of tangents at the tire radial center position of the terminal character 21 (i.e., the character width of the terminal character 21) is large in this way, the grinding body is likely to abut only a part of the terminal character 21 (the outer part in the tire circumferential direction) when it begins to hit the terminal character 21 (or when it moves away from the terminal character 21).Therefore, by setting the above-mentioned inclination angles Y1, Y2 and curvature radii R1, R2 in such a tire, the effects of the present invention can be more effectively achieved.

[0030] The present invention will be further explained below with reference to examples, but the scope of the present invention is not limited to these examples. [Example]

[0031] Tires were produced as Conventional Example 1, Comparative Examples 1 and 2, and Examples 1 to 9, each having a tire size of 215 / 65R16C 109 / 107Q and the basic structure (cross-sectional structure) illustrated in FIG. 1 , with the indicia structure being such that the inclination angle Y1, inclination angle Y2, radius of curvature R1, radius of curvature R2, and the range (percentage relative to character width X) of the outer portion of the end character in the tire circumferential direction (portion to which the inclination angle Y1 and / or radius of curvature R1 is applied) were set as shown in Tables 1 and 2.

[0032] In all examples, the process of polishing the surface of the display object (protrusion) was carried out by mounting each tire on a wheel with a rim size of 16 x 6.5, inflating it to an internal pressure of 200 kPa, and then mounting it on a dedicated polishing machine (buffing machine).

[0033] The surface condition of the markings and the amount of rubber used for these pneumatic tires were evaluated by the following evaluation methods, and the results are shown in Tables 1 and 2.

[0034] Surface condition of the display The surface condition of the markings (characters) formed on each tire was visually inspected. The evaluation results were rated as "poor" if the outer edge of the end character in the tire circumferential direction was excessively buffed, and "good" if there was no difference in the height of the raised portion of the character after buffing (no excessive buffing).

[0035] [Table 1]

[0036] [Table 2]

[0037] As is clear from Tables 1 and 2, the tires of Examples 1 to 9 suppressed excessive polishing (buffing) on ​​the circumferential outer side of the end letters, and were able to improve the surface condition of the indicia (preventing differences in protrusion height after polishing). On the other hand, in Comparative Example 1, because both the inclination angles Y1 and Y2 were small, the rigidity of the entire character string decreased, and it was not possible to improve the surface condition. In Comparative Example 2, because both the curvature radii R1 and R2 were small, the rigidity of the entire character string decreased, and it was not possible to improve the surface condition.

[0038] The present disclosure encompasses the following inventions. Invention [1] A tire comprising a tread portion extending in the circumferential direction of the tire and forming an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, wherein a plurality of indicia depicting letters, figures, or symbols are formed on the outer surface of the sidewall portion by the shape of the top surfaces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top surfaces of the protrusions constituting each of the plurality of indicia have a different color from the outer surface of the sidewall portion by exposing different colored rubber embedded in a portion of the sidewall portion, When a group of the plurality of marking elements in which the circumferential distance between adjacent marking elements is less than 20 mm is defined as a character string, and a pair of marking elements located at both ends of the character string in the tire circumferential direction are defined as end characters, The inclination angle Y1 formed by the wall surface of the tire circumferential outer portion of the end character with respect to the normal direction of the top surface of the end character is in the range of 5° to 10°, The tire is characterized in that the inclination angle Y1 is smaller than the inclination angle Y2 that the wall surfaces of other parts of the indicia included in the same character string as the terminal character make with respect to the normal direction of the top surface of each indicia. Invention [2] The tire according to invention [1], wherein the inclination angle Y2 is in the range of 10° to 20°. Invention [3] A tire comprising a tread portion extending in the circumferential direction of the tire to form an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, wherein a plurality of indicia depicting letters, figures, or symbols are formed on the outer surface of the sidewall portion by the shape of the top surfaces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top surface of the protrusions constituting each of the plurality of indicia has a different color from the outer surface of the sidewall portion by exposing different colored rubber embedded in a portion of the sidewall portion, When a group of the plurality of marking elements in which the circumferential distance between adjacent marking elements is less than 20 mm is defined as a character string, and a pair of marking elements located at both ends of the character string in the tire circumferential direction are defined as end characters, a wall surface of the end character at an outer portion in the tire circumferential direction smoothly connects to an outer surface of the sidewall portion via an arc-shaped connecting portion, and a curvature radius R1 of the connecting portion at the outer portion in the tire circumferential direction of the end character is in a range of 1 mm to 2 mm; The wall surface of another part of the indicia included in the same character string as the terminal character is smoothly connected to the outer surface of the sidewall portion via an arc-shaped connecting portion, and the radius of curvature R1 is smaller than the radius of curvature R2 of the connecting portion of the wall surface of the other part. Invention [4] The tire according to invention [3], characterized in that the radius of curvature R2 is in the range of 2 mm to 3 mm. Invention [5] When the angle formed by a pair of tangents drawn from the tire rotation axis to both ends of the circumferential direction of the terminal character is defined as the character width X (unit: °) of the terminal character, The tire according to any one of inventions [1] to [4], wherein the circumferentially outer portion of the terminal character is a portion that is circumferentially outer than a position that is 0.25 to 0.75 times the character width X from the circumferentially outer end of the terminal character. Invention [6] A tire according to any one of inventions [1] to [5], characterized in that when a pair of tangents are drawn from the tire rotation axis to both circumferential ends of the terminal character, the distance between the pair of tangents at the tire radial center position of the terminal character is 20 mm or more. [Explanation of symbols]

[0039] 1 Tread section 2 Sidewall 3 Bead section 4 carcass layers 5 bead core 6 Bead filler 7 Belt Layer 8 Belt reinforcement layer 10 Display items 10a Wall 10b Top surface 10c Connection 20 Strings 21 End Characters 21a Wall 21b Top surface 21c Connection CL Tire Equator E Ground end

Claims

1. A tire comprising a tread portion extending in the circumferential direction of the tire to form an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, wherein a plurality of indicia depicting letters, figures or symbols are formed on the outer surface of the sidewall portion by the shapes of the top surfaces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top surface of the protrusions constituting each of the plurality of indicia has a color different from that of the outer surface of the sidewall portion by exposing different colored rubber embedded in a portion of the sidewall portion, When a group of the plurality of marking objects in which the circumferential distance between adjacent marking objects is less than 20 mm is defined as a character string, and a pair of marking objects located at both ends of the character string in the tire circumferential direction are defined as end characters, an inclination angle Y1 formed by a wall surface of the tire circumferential outer portion of the terminal character with respect to a normal direction of the top surface of the terminal character is in a range of 5° to 10°; The tire is characterized in that the inclination angle Y1 is smaller than the inclination angle Y2 that the wall surfaces of other parts of the indicia included in the same character string as the terminal character make with respect to the normal direction of the top surface of each indicia.

2. 2. The tire according to claim 1, wherein the inclination angle Y2 is in the range of 10° to 20°.

3. A tire comprising a tread portion extending in the circumferential direction of the tire to form an annular shape, and a pair of sidewall portions disposed on both sides of the tread portion, wherein a plurality of indicia depicting letters, figures or symbols are formed on the outer surface of the sidewall portion by the shapes of the top surfaces of protrusions protruding from the outer surface of the sidewall portion, and at least a portion of the top surface of the protrusions constituting each of the plurality of indicia has a color different from that of the outer surface of the sidewall portion by exposing different colored rubber embedded in a portion of the sidewall portion, When a group of the plurality of marking objects in which the circumferential distance between adjacent marking objects is less than 20 mm is defined as a character string, and a pair of marking objects located at both ends of the character string in the tire circumferential direction are defined as end characters, a wall surface of the terminal character at an outer portion in the tire circumferential direction smoothly connects to an outer surface of the sidewall portion via an arc-shaped connecting portion, and a curvature radius R1 of the connecting portion at the outer portion in the tire circumferential direction of the terminal character is in a range of 1 mm to 2 mm, The wall surfaces of other parts of the indicia included in the same character string as the terminal character are smoothly connected to the outer surface of the sidewall portion via arc-shaped connecting portions, and the radius of curvature R1 is smaller than the radius of curvature R2 of the connecting portions of the wall surfaces of the other parts.

4. 4. The tire according to claim 3, wherein the radius of curvature R2 is in the range of 2 mm to 3 mm.

5. When the angle formed by a pair of tangents drawn from the tire rotation axis to both ends of the terminal character in the circumferential direction is defined as the character width X (unit: °) of the terminal character, The tire according to any one of claims 1 to 4, wherein the outer circumferential portion of the terminal character is a portion in the tire circumferential direction that is more outer than a position that is 0.25 to 0.75 times the character width X from the outer end of the terminal character in the tire circumferential direction.

6. The tire according to any one of claims 1 to 4, characterized in that when a pair of tangents is drawn from the tire rotation axis to both circumferential ends of the terminal character, the distance between the pair of tangents at the tire radial center position of the terminal character is 20 mm or more.

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