JP2008254280A - Tire mold, slick tire molding method, and slick tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tire mold capable of suppressing damage of a tread surface, a slick tire molding method, and a slick tire. <P>SOLUTION: The tire mold 1 which molds the slick tire having no groove, and is divided in the direction orthogonal to the mold width direction is equipped with a projecting wear pin 2 on the tread correspondent surfaces 11a, 12a corresponding to the tread surface of the slick tire. The wear pin 2 is formed to be gradually reduced in the direction where a diameter of the projecting part, that is, the diameter of the projected part 22 is projected since a pin wall angle θ is formed by 5 degree or more and 30 degree or less. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tire mold, a slick tire molding method, and a slick tire, and particularly to a tire mold, a slick tire molding method, and a slick tire that can form a wear gauge on a tread surface.

  Slick tires are mounted on vehicles that run on circuits. The slick tire has no groove formed on the tread surface. Therefore, the slick tire is provided with a wear gauge in order to confirm the wear state of the tread rubber constituting the tread surface. The wear gauge is formed in the tread surface so as to be recessed inward in the tire radial direction. Therefore, the wear situation of the tread rubber can be performed by confirming the depth of the wear gauge.

  As shown in Patent Documents 1 and 2, a wear pin capable of forming a wear gauge on a slick tire formed by a tire mold is formed on a tire mold for forming a slick tire. The wear pin protrudes from the tread corresponding surface corresponding to the tread surface of the slick tire.

JP 2005-47215 A JP 2000-255221 A

  By the way, the tire metal mold | die which forms a slick tire is divided | segmented and comprised in the direction orthogonal to a metal mold | die width direction. Therefore, after forming a slick tire by vulcanizing and molding a green tire using a tire mold, the tire mold is moved in the tire width direction of the slick tire when separating the slick tire from the tire mold. It will be. At this time, the wear pins of the tire mold can be removed from the tread surface of the slick tire. However, the wear pin moves in the tire width direction while contacting the tread surface as the tire mold moves in the tire width direction. Therefore, the wear pin moves in the tire width direction from the wear gauge while rubbing the tread surface of the slick tire, which may cause damage to the tread surface.

  This invention is made | formed in view of the above, Comprising: It aims at providing the tire metal mold | die, the slick tire shaping | molding method, and a slick tire which can suppress damage to a tread surface.

  In order to solve the above-described problems and achieve the object, in the present invention, a tread surface of a slick tire is formed in a tire mold in which a slick tire without a groove is formed and divided in a direction perpendicular to the mold width direction. And a wear pin projecting on a tread-corresponding surface, and the wear pin is formed such that the diameter of the projecting portion gradually decreases in the projecting direction.

  According to the present invention, in the tire mold, the wear pin is formed such that the pin wall angle is 5 degrees to 30 degrees with respect to the protruding direction.

  Further, in the slick tire molding method according to the present invention, a procedure for molding a green tire, a procedure for mounting the green tire on the tire mold, and expanding the green tire radially outward to contact the tire mold It includes a procedure, a procedure for heating and vulcanizing the green tire to form the green tire into a slick tire, and a procedure for separating the tire mold in the tire width direction of the slick tire.

  Further, in the present invention, in a slick tire without a groove, a wear gauge that is recessed inward in the tire radial direction is formed on the tread surface, and the wear gauge is formed with a diameter gradually decreasing toward the inner side in the tire radial direction. It is characterized by.

  In the present invention, in the slick tire, the wear gauge is characterized in that the gauge wall angle is formed at 5 to 30 degrees with respect to the protruding direction.

  According to the present invention, the wear pin is gradually reduced in the direction in which the protruding portion protrudes, for example, the pin wall angle is formed from 5 degrees to 30 degrees with respect to the protruding direction. When the slick tires are separated, even if they move in the tire width direction while being in contact with the tread surface, they are not easily caught on the tread surface. Accordingly, since the wear pin hardly rubs the tread surface of the slick tire, damage to the tread surface by the wear pin can be suppressed. Thereby, damage to the tread surface can be suppressed.

  According to the present invention, in the tire mold, the wear pin is chamfered at a portion connected to the tread-corresponding surface.

  In the present invention, in the above slick tire, the wear gauge is characterized in that a portion connected to the tread surface is chamfered.

  According to the present invention, when the slick tire is separated from the tire mold, the wear pin is chamfered at the portion connected to the tread corresponding surface, so that the portion connected to the tread surface of the wear gauge is chamfered. Therefore, it becomes easy to come off from the wear gauge. Further, even if the wear pin moves in the tire width direction while being in contact with the tread surface, the wear gauge and the tread surface are chamfered, so that the wear pin and the tread surface are not easily caught. Therefore, since the wear pin is less likely to rub the corner portion between the wear gauge and the tread surface, it is possible to suppress the corner portion between the wear gauge and the tread surface from being broken by the wear pin. Thereby, damage to the tread surface can be further suppressed.

  In the present invention, in the above slick tire, the tread rubber constituting the tread surface has a JIS hardness of 40 or less at 100 ° C.

  According to the present invention, the tread rubber constituting the tread surface is soft and easily damaged, but even if the wear pin moves in the tire width direction while in contact with the tread surface, it is difficult to be caught on the tread surface. Damage to the surface can be suppressed. Thereby, damage to the tread surface can be suppressed.

  The tire mold, the slick tire molding method, and the slick tire according to the present invention have an effect that damage to the tread surface can be suppressed.

  Hereinafter, the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiments. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or that are substantially the same.

[Embodiment]
First, a tire mold according to an embodiment will be described. FIG. 1 is a diagram illustrating a configuration example of a tire mold according to an embodiment. FIG. 2 is a diagram illustrating a configuration example of a wear pin. As shown in FIG. 1, the tire mold 1 according to the embodiment is divided into divisions in a direction orthogonal to the mold width direction. In the embodiment, the first tire mold 11 and the second tire mold 12 are divided into two. The inner wall surfaces of the first tire mold 11 and the second tire mold 12 are formed corresponding to the liquid state of the outer peripheral surface of the slick tire 5 (see FIG. 5) to be molded. Here, the inner wall surfaces are tread corresponding surfaces 11a and 12a corresponding to the tread surface 51 (see FIG. 5) of the slick tire 5 to be molded, sidewall corresponding surfaces 11b and 12b corresponding to the sidewall portions, and tire beads. Tire bead corresponding surfaces 11c and 12c corresponding to the portion. Wear pins 2 are provided on the tread corresponding surface 11 a of the first tire mold 11 and the tread corresponding surface 12 a of the second tire mold 12. In the embodiment, a plurality of wear pins 2 are provided at equal intervals in the mold circumferential direction on each tread corresponding surface 11a, 12a.

  The wear pin 2 forms a wear gauge on the tread surface 51 of the slick tire 5. As shown in FIG. 2, the wear pin 2 includes an insertion fixing portion 21 and a protruding portion 22. The insertion fixing portion 21 has a cylindrical shape, and is completely buried when inserted into the recesses formed on the tread corresponding surface 11a of the first tire mold 11 and the tread corresponding surface 12a of the second tire mold 12. Is set to Therefore, when the insertion pin 21 is inserted into the recesses formed in the tread corresponding surface 11a of the first tire mold 11 and the tread corresponding surface 12a of the second tire mold 12, the wear pin 2 is inserted and fixed. Only the protruding portion 21 that is integral with the protruding portion 11 protrudes from the tread corresponding surfaces 11a, 12a.

  The protruding portion 22 is a portion protruding from the tread corresponding surfaces 11 a and 12 a of the wear pin 2. In the embodiment, the protrusion 22 has a circular cross-sectional shape in a direction orthogonal to the central axis A of the wear pin 2. The protrusion 22 is configured by a pin wall surface 23 that is an outer peripheral surface and a tip surface 24 that is a tip surface. Here, the pin wall surface 23 is not formed perpendicular to the tread corresponding surfaces 11a and 12a, and the pin wall angle which is an angle formed by a line parallel to the central axis A of the wear pin 2 is the central axis. Inclined toward A. That is, the wear pin 2 is formed so as to be gradually reduced in the direction in which the diameter of the protruding portion, that is, the diameter of the protruding portion 22 protrudes (direction of arrow B in the figure). Here, the pin wall angle is preferably 5 degrees or more and 30 degrees or less. The pin wall angle is set to 5 degrees or more because if it is less than 5 degrees, the pin wall surface 23 is easily caught on the tread surface 51 of the slick tire 5, and the tread surface 51 of the slick tire 5 is easily rubbed. . In addition, when the pin wall angle is set to 30 degrees, the depth of the wear gauge 6 (see FIG. 6) formed by the wear pins 2 on the tread surface 51 of the slick tire 5 cannot be taken sufficiently. Therefore, in order to obtain a sufficient depth of the wear gauge 6 (see FIG. 6), the diameter of the protrusion 22 is increased, the opening surface of the tread 51 of the wear gauge 6 is widened, and the performance of the slick tire 5 is affected. It is because there is a possibility of giving.

  Further, the protruding portion 22 is formed such that the pin wall angle at the boundary with the insertion fixing portion 21 of the pin wall surface 23 is further inclined toward the central axis A of the wear pin 2. That is, the wear pin 2 has a tread-corresponding surface when the insertion fixing portion 21 is inserted into a recess formed in the tread-corresponding surface 11a of the first tire mold 11 and the tread-corresponding surface 12a of the second tire mold 12. The connection part 25 which is a part connected with 11a and 12a is chamfered. In the embodiment, the connecting portion 25 is chamfered. In addition, it is preferable that the C chamfering amount of the connection part 25 is 0.5 mm or more and 2.0 mm or less.

  Further, the protruding portion 22 is chamfered at the boundary portion between the pin wall surface 23 and the tip surface 24. In the embodiment, the boundary portion between the pin wall surface 23 and the tip surface 24 is rounded. The R chamfering amount at the boundary portion between the pin wall surface 23 and the tip surface 24 is preferably about 2.0 mm.

  Next, a slick tire molding method for molding a slick tire using the tire mold 1 according to the embodiment will be described. FIG. 3 is a diagram illustrating a flow of the slick tire molding method according to the embodiment. FIG. 4 is a diagram showing the relationship between the tire mold and the green tire. FIG. 5 is a diagram illustrating a configuration example of a slick tire formed by a tire mold. FIG. 6 is a diagram showing a wear gauge.

  First, as shown in FIG. 3, a green tire is molded (step ST1). Here, each member constituting the slick tire 5 (see FIG. 5) such as a belt, a carcass, a tread rubber (cap tread rubber, an under tread rubber, a side tread rubber), and a bead wire manufactured in the previous process is used. A green tire (raw tire) 4 (see FIG. 4) is molded by a molding machine (not shown).

  Next, the molded green tire 4 is mounted on the tire mold 1 (step ST2). Here, the first tire mold 11 in which the wear pin is inserted and fixed in the concave portion of the tread corresponding surface 11a and the second tire mold 12 in which the wear pin is inserted and fixed in the concave portion of the tread corresponding surface 12a are separated from each other. Then, the molded green tire 4 is arranged between the first tire mold 11 and the second tire mold 12, and the first tire mold 11 and the second tire mold 12 are integrated by a fixing means (not shown). To fix. At this time, the bladder main body 31 of the bladder apparatus 3 (see FIG. 4) is disposed inside the green tire 4.

  Next, the green tire 4 is expanded by the bladder device 3 (step ST3). Here, as shown in FIG. 4, the bladder device 3 inflates a bladder main body 31 disposed inside the green tire 4, pressurizes the green tire 4 with the bladder main body 31, and then moves the green tire 4 radially outward. Extend towards. Thereby, the outer peripheral surface of the green tire 4 is brought into contact with the tread corresponding surfaces 11a and 12a, the sidewall corresponding surfaces 11b and 12b, and the tire bead corresponding surfaces 11c and 12c, which are the inner wall surfaces of the tire mold 1.

  Next, as shown in FIG. 3, the green tire is heated by the bladder device 3 (step ST4). Here, the bladder apparatus 3 is in a state in which the green tire 4 is in contact with the tread corresponding surfaces 11a and 12a, the sidewall corresponding surfaces 11b and 12b, and the tire bead corresponding surfaces 11c and 12c, which are the inner wall surfaces of the tire mold 1. In a state where the tire 4 is pressurized, the green tire 4 is heated by introducing, for example, heated steam into the bladder main body 31. Thereby, the green tire 4 is vulcanized and the slick tire 5 is molded as shown in FIG. As shown in FIG. 4, the wear pin 2 enters the tread of the green tire 4 when the green tire 4 is formed into the slick tire 5. Therefore, the molded slick tire 5 is formed with a wear gauge 6 to which the outer shape of the wear pin 2 is transferred, as shown in FIG.

  The wear gauge 6 is formed in the tread surface 51 of the slick tire 5 so as to be recessed inward in the tire radial direction, that is, in the direction of arrow E in the figure. In the embodiment, the wear gauge 6 has a circular cross-sectional shape in a direction orthogonal to the central axis C of the wear gauge 6. The wear gauge 6 includes a bottom surface 61, a gauge wall surface 62, and a connection surface 63. The bottom surface 61 is formed by transferring the tip surface 24 of the wear pin 2. The gauge wall surface 62 is formed by transferring the pin wall surface 23 of the wear pin 2. The connection surface 63 is formed by transferring the chamfered surface of the connection portion 25 of the wear pin 2. Accordingly, the gauge wall surface 62 is not formed perpendicular to the tread surface 51, and the gauge wall angle, which is an angle formed by the line parallel to the central axis C of the wear gauge 6, is directed toward the central axis C. Inclined. That is, the wear gauge 6 is formed such that its diameter gradually decreases toward the inside in the tire radial direction (in the direction of arrow E in the figure). The gauge wall angle is the same as the pin wall angle of the wear pin 2 and is not less than 5 degrees and not more than 30 degrees.

  The wear gauge 6 is formed by the connecting portion 25 of the wear pin 2 such that the gauge wall angle at the boundary with the tread surface 51 in the gauge wall surface 61 is further inclined toward the central axis C of the wear gauge 6. The That is, the wear gauge 6 is chamfered at a portion where the gauge wall surface 61 and the tread surface 51 are connected. In the embodiment, C-chamfering is performed to form the connection surface 63. In addition, the C chamfering amount of the portion connecting the gauge wall surface 61 and the tread surface 51 is the same as the C chamfering amount of the connection portion 25 of the wear pin 2 and is 0.5 mm or more and 2.0 mm or less. The wear gauge 6 is chamfered at the boundary between the gauge wall surface 61 and the bottom surface 62. In the embodiment, since the boundary portion between the pin wall surface 23 and the tip surface 24 of the wear pin 2 is chamfered, the boundary portion between the gauge wall surface 61 and the bottom surface 62 is chamfered. The R chamfering amount at the boundary portion between the gauge wall surface 61 and the bottom surface 62 is about 2.0 mm, where the boundary portion between the pin wall surface 23 and the tip surface 24 of the wear pin 2 is the same as the R chamfering amount.

  Next, the first tire mold 11 and the second tire mold 12 are separated (step ST5). Here, at the time of vulcanization molding, the first tire mold 11 and the second tire mold 12 that are integrated with each other by releasing the fixing by the fixing means are respectively in the mold width direction, that is, the molded slick tire 5. The tires are separated in the tire width direction. At this time, the wear pin 2 comes out of the wear gauge 6 formed on the slick tire 5 and moves in the tire width direction while contacting the tread surface 51. Here, since the wear pin 2 is formed by gradually decreasing the diameter of the protruding portion, that is, the diameter of the protruding portion 22 in the protruding direction, when the slick tire 5 is separated from the tire mold 1, the tread surface Even if the tire 51 moves in the tire width direction while being in contact with 51, it is difficult to be caught on the tread surface 51. Therefore, since the wear pin 2 is less likely to rub the tread surface 51 of the slick tire 5, damage to the tread surface 51 by the wear pin 2 can be suppressed. In addition, when the slick tire 5 is separated from the tire mold 1, the wear pin 2 is chamfered because the connecting portion 25 is chamfered, so that the portion connecting the tread surface 51 of the wear gauge 6 is chamfered. It becomes easy to come off from the wear gauge 6. Even if the wear pin 2 moves in the tire width direction while being in contact with the tread surface 51, the wear gauge 6 and the tread surface 51 are chamfered, so that the wear pin 6 is caught at the corner of the tread surface 51. It becomes difficult. Therefore, the wear pin 2 is less likely to rub the corners of the wear gauge 6 and the tread surface 51, so that the corners of the wear gauge 6 and the tread surface 51 can be prevented from being broken by the wear pin 2. As a result, damage to the tread surface 51 can be suppressed.

  In the above embodiment, it is preferable that the tread rubber used for the slick tire 5 has a JIS hardness (JIS K6253) at 100 ° C. of 40 or less. That is, it is preferable to soften the tread rubber constituting the tread surface 51 of the slick tire 5. In this case, the tread rubber 51 constituting the tread surface 5 is soft and easily damaged. However, even if the wear pin 2 moves in the tire width direction while being in contact with the tread surface 51, the wear pin is not easily caught on the tread surface 51. 2, damage to the tread surface 51 can be suppressed. Thereby, when using the rubber | gum 40 or less by JIS hardness (JISK6253) in 100 degreeC as a tread rubber for the slick tire 5, damage to the tread surface 51 can be suppressed remarkably.

  Moreover, in the said embodiment, although the connection part 25 of the wear pin 2 is chamfered, this invention is not limited to this. R may be chamfered. In this case, the connection surface 63 of the wear gauge 6 has a curved section in the axial direction.

  Moreover, in the said embodiment, although the cross-sectional shape in the direction orthogonal to the central axis A of the wear pin 2 was circular, this invention is not limited to this, Ellipse shape etc. may be sufficient.

  Below, the slick tire produced | generated by the slick tire shaping | molding method using the conventional wear pin and the slick tire produced | generated by the slick tire shaping | molding method using the wear pin concerning this invention were compared. The conventional slick tire and the slick tire of the present invention have a common tire size of 250 (ground contact width (mm)) / 515 (outer diameter (mm))-13 (rim diameter (inch)). In the conventional slick tire and the slick tire of the present invention, 20 wear gauges are formed by 20 wear pins.

  Here, the diameter D (mm) is the diameter of the protruding portion at the location where the pin wall surface of the wear pin (excluding the connecting portion if it has a connecting portion) and the tread corresponding surface intersect (see FIG. 2). ). That is, the diameter D (mm) is a diameter at a location where the gauge wall surface of the wear gauge (excluding the connection surface if it has a connection surface) and the tread surface (see FIG. 6). The height H (mm) is the height from the tread-corresponding surface to the tip surface of the wear pin (see FIG. 2). That is, the height D (mm) is the depth from the tread surface to the bottom surface of the wear gauge (see FIG. 6). The top radius R (mm) is the R chamfering amount at the boundary between the pin wall surface and the tip surface of the wear pin (see FIG. 2). That is, the top radius R (mm) is the R chamfering amount at the boundary between the gauge wall surface and the bottom surface of the wear gauge (see FIG. 6). The pin wall angle θ (°) is the pin wall angle of the wear pin (see FIG. 2). That is, the pin wall angle θ (°) is the gauge wall angle of the wear gauge (see FIG. 6). Moreover, the presence or absence of chamfering is whether or not C chamfering is performed at the boundary portion between the pin wall surface of the wear pin and the tread-corresponding surface. That is, the presence / absence of chamfering is whether or not a chamfering is performed at the boundary between the gauge wall surface of the wear gauge and the tread surface, and a connection surface is formed. The rubber hardness is the rubber hardness of the tread rubber and is the JIS hardness at 100 ° C. The degree of damage (%) is the ratio of the number of damaged parts to% of the number of all wear pins when the slick tire is separated from the tire mold. That is, the lower the damage degree (%), the less the tread surface is damaged.

  The “conventional example” has a diameter D (mm) = 6, a height H (mm) = 4, a top radius R (mm) = 2, a pin wall angle θ (°) = 0, and a wear pin without chamfering. A slick tire formed from a green tire having a tread rubber hardness of 31 by the slick tire forming method used.

  “Example 1” has a diameter D (mm) = 6, a height H (mm) = 4, a top radius R (mm) = 2, a pin wall angle θ (°) = 3, and a wear pin without chamfering. A slick tire formed from a green tire having a tread rubber rubber hardness of 31 by a slick tire molding method using

  Further, “Example 2” has a diameter D (mm) = 6, a height H (mm) = 4, a top radius R (mm) = 2, a pin wall angle θ (°) = 5, and a wear pin without chamfering. A slick tire formed from a green tire having a tread rubber rubber hardness of 31 by a slick tire molding method using

  “Example 3” has a diameter D (mm) = 6, a height H (mm) = 4, a top radius R (mm) = 2, a pin wall angle θ (°) = 30, and a wear pin without chamfering. A slick tire formed from a green tire having a tread rubber rubber hardness of 31 by a slick tire molding method using

  “Example 4” has a diameter D (mm) = 6, a height H (mm) = 4, a top radius R (mm) = 2, a pin wall angle θ (°) = 5, and a chamfer (C chamfering). This is a slick tire formed from a green tire having a rubber hardness of 31 of a tread rubber by a slick tire forming method using a wear pin having a quantity of 1 mm).

  In the “conventional example”, the damage degree (%) = 90, in the “Example 1”, the damage degree (%) = 80, in the “Example 2”, the damage degree (%) = 50, and in the “Example 3”, the damage degree (%). %) = 20, and in “Example 4”, the degree of damage (%) = 0.

  As is apparent from Table 1, the pin wall angle θ (°) <0, that is, the slick tire molding method using a wear pin in which the diameter of the projecting portion gradually decreases in the projecting direction was molded from the green tire. “Example 1 to Example 4” which are slick tires have a pin wall angle θ (°) = 0, that is, a slick tire molding method using a wear pin in which the diameter of the protruding portion is constant in the protruding direction. As a result, the degree of damage (%) is reduced compared to the “conventional example” which is a slick tire formed from a green tire, and damage to the tread surface can be suppressed. In particular, “Example 2 to Example 4”, which are slick tires formed from green tires by a slick tire forming method using a wear pin having a pin wall angle θ (°) of 5 ≦ θ ≦ 30, As compared with the “conventional example”, damage to the tread surface can be reliably suppressed. Furthermore, “Example 4”, which is a slick tire formed from a green tire by a slick tire forming method using chamfered wear pins, significantly suppresses tread surface damage compared to “conventional example”. Is done.

  As described above, the tire mold, the slick tire molding method, and the slick tire according to the present invention are useful for a slick tire in which a wear gauge is formed on the tread surface, and are suitable for suppressing damage to the tread surface. .

It is a figure which shows the structural example of the tire metal mold | die concerning Embodiment. It is a figure which shows the structural example of a wear pin. It is a figure which shows the flow of the slick tire shaping | molding method concerning embodiment. It is a figure which shows the relationship between a tire metal mold | die and a green tire. It is a figure which shows the structural example of the slick tire shape | molded by the tire metal mold | die. It is a figure which shows a wear gauge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Tire mold 11 1st tire mold 11a Tread corresponding surface 11b Side wall corresponding surface 11c Tire bead corresponding surface 12 2nd tire mold 12a Tread corresponding surface 12b Side wall corresponding surface 12c Tire bead corresponding surface 2 Wear pin 21 Insertion fixing Part 22 Projection part 23 Pin wall surface 24 Tip surface 25 Connection part 3 Bladder device 31 Bladder body 4 Green tire 5 Slick tire 51 Tread surface 6 Wear gauge 61 Bottom surface 62 Gauge wall surface 63 Connection surface

Claims (8)

In the tire mold formed into a slick tire without a groove and divided in the direction perpendicular to the mold width direction,
A wear pin protruding on the tread corresponding surface corresponding to the tread surface of the slick tire,
The tire mold is characterized in that the wear pin is formed so that the diameter of the protruding portion gradually decreases in the protruding direction.   2. The tire mold according to claim 1, wherein the wear pin has a pin wall angle of 5 degrees to 30 degrees with respect to a protruding direction.   The tire mold according to claim 1 or 2, wherein the wear pin is chamfered at a portion connected to the tread-corresponding surface. The procedure for molding green tires,
A procedure for mounting a green tire on the tire mold according to any one of claims 1 to 3,
Extending the green tire radially outward and contacting the tire mold;
The green tire is heated and vulcanized to form the green tire into a slick tire,
Separating the tire mold in the tire width direction of the slick tire;
A slick tire molding method comprising: In slick tires without grooves,
A wear gauge recessed on the inner side in the tire radial direction is formed on the tread surface,
The slick tire is characterized in that the wear gauge is formed with a diameter gradually decreasing toward an inner side in a tire radial direction.   The slick tire according to claim 5, wherein the wear gauge has a gauge wall angle of 5 degrees to 30 degrees with respect to the protruding direction.   The slick tire according to claim 5 or 6, wherein the wear gauge is chamfered at a portion connected to the tread surface.   The slick tire according to any one of claims 5 to 7, wherein the tread rubber constituting the tread surface has a JIS hardness at 100 ° C of 40 or less.

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