JP6472018B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire.

  In general, the tread surface of a pneumatic tire is provided with a colored identification display called an identification line that extends in the tire circumferential direction in order to identify the type of tire. The identification mark is formed by applying a paint with a color different from the color of the tread rubber (usually black) to the surface of the unvulcanized tread rubber. The tread surface of the pneumatic tire after vulcanization molding 1 or more are provided over the entire circumference in the tire circumferential direction. For example, Patent Document 1 discloses that the identification line is formed in a broken line shape having two or more broken parts in the tire circumferential direction in order to reduce the amount of paint used for the identification line.

  Patent Document 2 discloses that a decorative pattern is provided by providing a pattern on the surface film covering at least a part of the outer surface of the tire. However, the surface film of Patent Document 2 is intended to improve tire performance such as wear resistance, and is a technique different from the above identification display that does not contribute to improvement of such tire performance, There is no disclosure about the relationship between the circumferential main grooves and the ribs partitioned thereby and the identification indications.

JP 11-59125 A JP 2005-504671 A

  As described above, the identification display is formed on the surface of the tread rubber in the unvulcanized stage, but a predetermined uneven pattern such as a circumferential main groove is formed on the tread surface during vulcanization molding of the tire. At this time, if the identification display falls on the groove bottom of the circumferential main groove, it is difficult to visually confirm the identification display in the vulcanized pneumatic tire, and it is difficult to detect it by a detection device such as a camera. Since there is also a request to reduce the amount of paint used as described in Patent Document 1, generally the identification display is sufficiently larger than the width of the circumferential main groove as an identification line having a thickness of about 3 mm. It is formed thinly, and there is a concern that the discriminability deteriorates due to the drop of the circumferential main groove into the groove bottom.

  In view of the above points, an object of the present invention is to provide a pneumatic tire that can reduce the drop of the identification display provided on the tread surface into the circumferential main groove.

In the pneumatic tire according to the present embodiment, a rib extending in the tire circumferential direction defined by a circumferential main groove is provided in the tread portion, and a colored identification display extending in the tire circumferential direction is provided on the surface of the rib. The width of the identification display is set larger than the groove width of the circumferential main groove, and the identification display has the same or different basic pattern in the tire circumferential direction having a constant aspect ratio and the same vertical dimension. A row of repeated patterns arranged in parallel without a gap is formed by arranging a plurality of rows without gaps in the tire width direction.
In the manufacturing method of the pneumatic tire according to the present embodiment, ribs extending in the tire circumferential direction defined by the circumferential main grooves are provided in the tread portion, and the colored identification extending in the tire circumferential direction is provided on the surface of the rib. A pneumatic tire manufacturing method in which an indication is provided and a width of the identification indication is set larger than a groove width of the circumferential main groove, the aspect ratio being constant on a tread rubber surface of an unvulcanized tire. There is provided an identification display in which rows of repeated patterns in which the same or different basic patterns having the same vertical dimension are arranged in the tire circumferential direction without any gaps are arranged in a plurality of rows without gaps in the tire width direction, and the unvulcanized The identification indication is provided on the surface of the rib by vulcanizing a tire.

  According to the present embodiment, since the identification indication provided on the rib surface of the tread portion is set wider than the groove width of the circumferential main groove defining the rib, the drop of the identification indication into the circumferential main groove is reduced. It is possible to improve discrimination.

The partial expansion perspective view of the pneumatic tire concerning a 1st embodiment. The principal part enlarged plan view of the tread part of the pneumatic tire. The principal part enlarged plan view of the tread part which shows the example of a change of identification display. The principal part enlarged plan view of the tread part which shows the further example of a change of identification display. The partial expansion perspective view of the pneumatic tire which concerns on 2nd Embodiment.

(First embodiment)
As shown in FIG. 1, a pneumatic tire 10 according to the present embodiment is a tire for passenger cars, and a pair of left and right bead portions 12 and sidewall portions 14 and outer ends of the left and right sidewall portions 14 in the tire radial direction. The tread part 16 which connects parts is provided, The structure similar to a well-known pneumatic tire except the surface structure of the tread part 16 is employable.

  A plurality of (four in this example) straight circumferential main grooves 18 extending in the tire circumferential direction C are provided on the surface of the tread portion 16. In this example, the circumferential main groove 18 is disposed on the outer side in the tire width direction W of the pair of center main grooves 18A and 18A disposed on both sides of the tire equator line and the pair of center main grooves 18A and 18A, respectively. And a pair of shoulder main grooves 18B, 18B.

  A plurality of land portions are defined in the tread portion 16 by the circumferential main grooves 18. Specifically, the tread portion 16 includes a central land portion 20 formed between the pair of left and right center main grooves 18A and 18A, and a pair of left and right intermediate portions formed between the center main groove 18A and the shoulder main grooves 18B. Land portions 22, 22 and a pair of left and right shoulder land portions 24, 24 formed on the outer side in the tire width direction W of the pair of left and right shoulder main grooves 18B, 18B are provided. Among them, the intermediate land portion 20 located in the central portion of the tread portion 16 is formed as a rib extending continuously in the tire circumferential direction C, and is hereinafter referred to as a central rib 20.

  A colored identification display 26 extending in the tire circumferential direction C is provided on the surface (ground contact surface) of the central rib 20. The identification display 26 is a colored layer of a thin film having a color that is conspicuous with respect to the black tread rubber, for example, white, yellow, blue, red, and the like, for example, on the tread rubber surface in the unvulcanized stage. It can be formed by transferring a paint such as a color rubber paint with a transfer roll or the like, or applying a tape having color.

  The identification display 26 is wider than the conventional identification line, and as shown in an enlarged view in FIG. 2, the width w1 of the identification display 26 is larger than the groove width w2 of the center main groove 18A that defines the central rib 20. Is also set larger (w1> w2). Thus, by setting the identification display 26 to be wide, it is possible to reduce the drop of the identification display 26 into the bottom of the center main groove 18A. Although it does not specifically limit, it is preferable that the width | variety w1 of the identification display 26 is more than 15 mm and 30 mm or less, More preferably, it is 20-30 mm. In addition, the width w1 of the identification display 26 is preferably larger than 50% of the width w3 of the central rib 20 (w1> 0.5 × w3), more preferably 70 to 80% of the width w3 of the central rib 20. is there. In this example, the groove width w2 of the center main groove 18A on both sides of the central rib 20 is the same, but the groove widths on both sides may be different. In this case, the width w1 of the identification display 26 is wider. It is preferably larger than the groove width w2 of the center main groove 18A having the groove width.

  The identification display 26 is an identification pattern composed of a repeating pattern in the tire circumferential direction C, and is formed over the entire circumference in the tire circumferential direction C. In this example, the identification display 26 is a continuous pattern design in which basic patterns 28 having a circular contour shape are arranged without gaps in the tire circumferential direction C. More specifically, the aspect ratio of the basic pattern 28 is constant. The circular pattern of the same size is formed in a repeated pattern in which the same pattern is arranged in a line in the tire circumferential direction C without any gap. By setting it as such a repeating pattern, the rubber flow defect of the tread rubber at the time of tire vulcanization molding can be visually confirmed. That is, at the time of vulcanization molding, the tread rubber is pressed against the mold surface while being expanded in the tire radial direction to be molded into a desired uneven shape. At this time, if a rubber flow failure occurs, the tread rubber is evenly distributed in the tire circumferential direction C. There is a case where local expansion or contraction occurs without expansion. On the other hand, if the repetitive pattern identification display 26 as described above is provided, it is easy to determine whether or not the stretched pattern is uniformly extended due to the variation in the deformation of the basic pattern 28 in the tire circumferential direction C, and it is possible to confirm the rubber flow failure. Easy. In addition, by providing such a wide identification display 26 made of a repeated pattern, it is possible to give a conspicuous decorative property when displayed at a retail store, for example.

  Here, the outline of the basic pattern 28 is a concept including not only a perfect circle but also an ellipse. Therefore, the circular pattern as the basic pattern 28 may be a perfect circle or an ellipse at the stage after vulcanization molding. For example, a perfect circle may be formed into an ellipse by vulcanization molding at the stage of an unvulcanized tire (green tire). It may be shaped, and these are collectively called a circular pattern.

  The aspect ratio is a ratio x between the vertical dimension x which is the size of the basic pattern 28 in the tire circumferential direction C and the horizontal dimension y which is the size in the tire width direction W (y = w1 in this example). / Y. The aspect ratio may be, for example, x / y = 1/1 at the stage of an unvulcanized tire. In that case, the degree of expansion in the tire circumferential direction C by vulcanization molding is easy to understand, and visual confirmation of rubber flow failure is possible. It becomes easier. Alternatively, the aspect ratio may be set so that x / y = 1/1 after vulcanization molding in consideration of the expansion ratio in the tire circumferential direction C at the time of vulcanization molding. can do.

  Note that the longitudinal dimension x and the lateral dimension y are the dimensions of the major axis and the minor axis arranged along the tire circumferential direction C and the width direction W (when the contour shape of the basic pattern 28 is circular as in the present embodiment ( In case of a perfect circle, it is equal to the diameter)

  According to the present embodiment described above, since the identification display 26 provided on the surface of the rib 20 of the tread portion 16 is set wider than the groove width w2 of the circumferential main groove 18A that defines the rib 20, the identification display 26 Can be reduced, and discriminability can be ensured. In addition, by configuring the wide identification display 26 with a repeating pattern in the tire circumferential direction C, it is possible to visually confirm the rubber flow failure of the tread rubber at the time of tire vulcanization molding. It can have a decorative appearance that stands out when displayed. Moreover, by using a continuous pattern design in which the basic patterns 28 are arranged without gaps in the tire circumferential direction C, it is possible to make it easier to visually check the rubber flow failure.

(Example of change)
FIGS. 3A to 3E show identification displays 26A to 26E according to the modified example of the first embodiment. These identification indications 26A to 26E are made of a repetitive pattern in the tire circumferential direction C, and are a continuous pattern in which basic patterns 28A to 28E having a circular or rectangular contour shape are arranged in the tire circumferential direction C and the tire width direction W without any gaps. It has a design. Specifically, in an example in which rows 29 of repeated patterns in which basic patterns 28A to 28E having the same aspect ratio and the same size are arranged side by side in the tire circumferential direction C are arranged in two rows in the tire width direction W without gaps. is there. As described above, by providing the basic patterns 28A to 28E side by side not only in the tire circumferential direction C but also in the tire width direction W, it becomes easier to visually confirm the rubber flow failure.

  In the example of FIG. 3A, a circular pattern similar to that of the first embodiment is adopted as the basic pattern 28A, and two rows 29 of repeating patterns of the basic pattern 28A are arranged. Since there are two rows, the width w1 of the identification display 26A is twice the horizontal dimension y of the basic pattern 28A (w1 = y × 2). This also applies to the examples of FIGS. 3 (b) to 3 (e). In this way, when the basic pattern rows are arranged in a plurality of rows, the width of the identification display is an integral multiple of the horizontal dimension of the basic pattern.

  In the example of FIG. 3B, a pattern having a coloring portion between a rectangle and a circle (true circle or ellipse) inscribed therein is defined as a basic pattern 28B. In the example of FIG. 3C, a basic pattern 28C is a pattern in which a rectangle that forms an outline is half colored with the diagonal line as a boundary. In the example of FIG. 3D, a pattern having only a rectangular outline portion as a coloring portion is used as a basic pattern 28D. Therefore, the identification display 26D is formed in a lattice pattern. In the example of FIG. 3E, a basic pattern 28E is obtained by adding a rhombus coloring portion to the inside of the rectangular outline portion of the basic pattern 28D of FIG. 3D.

  FIGS. 4A and 4B show identification displays 26F and 26G according to a further modification of the first embodiment. In the example of FIG. 4 (a), a rectangle forming an outline is divided into four parts by dividing it vertically and horizontally, and a pattern in which two regions on the diagonal line are colored portions is defined as a basic pattern 28F. A continuous pattern design in which the basic patterns 28F are arranged in a line in the tire circumferential direction C without any gap is used as an identification display 26F. Therefore, in this example, the width w1 of the identification display 26F is equal to the horizontal dimension y of the basic pattern 28F.

  In the example of FIG. 4B, the identification display 26G has a continuous pattern design in which the identification displays 26F of FIG. That is, the identification display 26G is an example in which the repeated pattern rows 29 in which the basic patterns 28F are arranged side by side in the tire circumferential direction C are arranged in two rows in the tire width direction W without gaps.

  In addition, the rectangle which makes the outline shape of said basic pattern 28B-28F is a concept containing a square and a rectangle, and the square of aspect ratio x / y = 1/1 may be sufficient in the stage after vulcanization molding, and vulcanization molding A rectangular shape may be used at a later stage. For example, a square shape may be formed into a rectangular shape by vulcanization molding at the stage of an unvulcanized tire. Further, in this case, the vertical dimension x and the horizontal dimension y are equal to the length of a rectangular side disposed along the tire circumferential direction C and the width direction W.

  Regarding the modified examples of FIGS. 3A to 3E and FIGS. 4A and 4B, other configurations and operational effects are the same as those of the first embodiment, and the description thereof is omitted.

(Second Embodiment)
FIG. 5 shows a pneumatic tire 10A according to the second embodiment, and the configuration of the identification display provided on the central rib 20 is different from that of the first embodiment. In this embodiment, the identification display 26H is configured by a character string.

  Specifically, the identification display 26 </ b> H is configured as a repetitive pattern extending in the tire circumferential direction C by repeatedly arranging the character string 30 composed of characters arranged in the tire circumferential direction C in the tire circumferential direction C. Yes. Here, examples of characters include Roman characters, Kanji characters, kana characters, numbers, emoticons, etc., and may be designed characters, or may be used in appropriate combinations. Examples of the character string include a trademark, a manufacturer name, a dealer name, a product name, and a tire size, and these may be appropriately combined. In the illustrated example, the identification display 26 </ b> H is a pattern in which “TOYO TIRES” is used as a character string and this is repeated over the entire circumference in the tire circumferential direction C.

  The width w1 of the identification display 26H (in this case, the width of the character string 30 in the tire width direction W) is set to be larger than the width w2 of the center main groove 18A that defines the central rib 20, as in the first embodiment. Thus, the drop of the identification display 26H into the center main groove 18A can be reduced. Further, the width w1 of the identification display 26H is larger than 50% of the width w3 of the central rib 20, and more preferably 70 to 80% of the width w3 of the central rib 20.

  According to 2nd Embodiment, since the identification display 26H is comprised from the repeating pattern of the character string 30, the decorativeness which is conspicuous at the time of the display in a retail store, for example can be given. Moreover, it is also possible to visually confirm the rubber flow failure of the tread rubber at the time of tire vulcanization molding by confirming the presence or absence of deformation variation of the character string 30. Further, in terms of tire identification, not only changing the color, but also including, for example, a product name and a tire size in a character string allows easy identification. About 2nd Embodiment, the other structure and effect are the same as that of 1st Embodiment, and description is abbreviate | omitted.

(Other embodiments)
In the said 1st Embodiment, it was set as the structure which arrange | positions the row | line | column 29 which consists of the repeating pattern of the basic patterns 28 and 28A-28F 1 row | line | column or 2 rows, but you may provide 3 or more rows. Further, when a plurality of rows are provided, even if the rows have different basic patterns, they can be arranged in combination as long as they have a constant aspect ratio and the same size. For example, the basic patterns 28A shown in FIG. 3 may be combined with the row 29 of the basic pattern 28E shown in FIG. 3E to sandwich the row 29 of one basic pattern 28E between the rows 29 of the two basic patterns 28A. .

  In the first embodiment, the same basic pattern 28, 28A to 28F is a repeated pattern in the tire circumferential direction C. However, if the aspect ratio is constant and has the same size, different basic patterns are used for the tire circumference. The identification display may be configured with no gap in the direction. In other words, the continuous pattern design for the identification display is a pattern in which basic patterns having the same size and the same aspect ratio are arranged in the tire circumferential direction or the tire circumferential direction and the tire width direction without gaps. If so, the basic pattern may be composed of one kind or a combination of two or more kinds.

  In the second embodiment, the identification display H is composed of only the character string 30. However, the repetition of the basic pattern 28 and the character string 30 as in the first embodiment may be combined. Furthermore, the identification display is not limited to the repeating pattern in the tire circumferential direction as in the first and second embodiments, and may be constituted by, for example, a simple thick line.

  In the above embodiment, the identification indication 26 is provided on the central rib 20 of the tread portion 16. However, if the intermediate land portion 22 and the shoulder land portion 24 are ribs extending continuously in the tire circumferential direction C, they are provided on these ribs. Moreover, you may provide not only one rib but a several rib.

  Although some embodiments have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

  The present invention can be used for various types of pneumatic tires such as tires for passenger cars and tires for heavy loads such as trucks and buses.

DESCRIPTION OF SYMBOLS 10,10A ... Pneumatic tire, 16 ... Tread part, 18 ... Circumferential main groove, 20 ... Center rib, 26, 26A-H ... Identification display, 28, 28A-F ... Basic pattern, 30 ... Character string, w1 ... Width of identification display, w2 ... width of center main groove, w3 ... width of center rib, C ... tire circumferential direction

Claims (3)

A rib extending in the tire circumferential direction defined by a circumferential main groove is provided in the tread portion, and a colored identification display extending in the tire circumferential direction is provided on a surface of the rib, and the width of the identification display is the circumference. Set larger than the groove width of the direction main groove,
In the identification display, repeated pattern rows in which the same or different basic patterns having the same aspect ratio and the same vertical dimension are arranged in the tire circumferential direction without any gaps are arranged in a plurality of rows without gaps in the tire width direction. Formed pneumatic tire.   The pneumatic tire according to claim 1, wherein the width of the identification display is larger than 50% of the width of the rib. A rib extending in the tire circumferential direction defined by a circumferential main groove is provided in the tread portion, and a colored identification display extending in the tire circumferential direction is provided on a surface of the rib, and the width of the identification display is the circumference. A pneumatic tire manufacturing method set larger than the groove width of the direction main groove,
On the tread rubber surface of an unvulcanized tire, there are multiple rows of repeating patterns in which the same or different basic patterns having the same aspect ratio and the same vertical dimensions are arranged side by side in the tire circumferential direction with no gaps in the tire width direction. A method for manufacturing a pneumatic tire, wherein identification indications arranged in a row are provided, and the identification indication is provided on a surface of the rib by vulcanizing the unvulcanized tire.

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