JP2014162447A - Pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pneumatic tire that can suppress growth of crack generated in a side wall portion by a decorative portion and secure appropriately visibility of the decorative portion.SOLUTION: In the pneumatic tire, a plurality of ridges 11a, 12a and 13a extending in parallel to a first side are provided in quadrilateral patterns 11, 12 and 13 forming a decorative portion 10; the quadrilateral patterns 11, 12 and 13 with different directions of the ridges 11a, 12a and 13a are arranged so that the first sides and the second sides thereof are adjacent to each other; and quadrilateral regions 14 without the ridges 11a, 12a and 13a are formed between the first sides of the quadrilateral patterns 11, 12 and 13 in which directions of the ridges 11a, 12a and 13a are respectively the same and the first sides are adjacent to each other, so that growth of crack can be suppressed by the decorative portion 10 and visibility of the decorative portion 10 can be secured appropriately.

Description

  The present invention relates to a pneumatic tire used in, for example, passenger cars, trucks, buses and the like.

  In general, this type of pneumatic tire is provided with a decorative portion composed of a plurality of ridges on the outer surface of the sidewall portion, and each ridge is formed so as to extend linearly in parallel with the adjacent ridge. Those arranged at equal intervals in the direction are known (for example, see Patent Document 1).

JP 2004-224342 A

  By the way, in the pneumatic tire, each ridge is formed so as to extend linearly in parallel with the adjacent ridge, and is arranged at equal intervals in the tire circumferential direction. When cracks are generated on the outer surface, the cracks are likely to grow along the ridge. In addition, the decorative portion is provided to improve the design of the side wall portion. However, in the conventional example, since each ridge is formed so as to extend in the same direction, depending on the viewing direction, the decorative portion by the ridge and other portions may be provided. There is also a problem in that the brightness of the part is not generated and the visibility of the decorative part is lowered.

  The present invention has been made in view of the above-described problems, and the object of the present invention is to suppress the growth of cracks generated in the sidewall portion by the decorative portion and sufficiently enhance the visibility of the decorative portion. The object is to provide a pneumatic tire that can be secured.

  In order to achieve the above object, the present invention provides a pneumatic tire having a decorative portion on an outer surface of a sidewall portion, wherein the decorative portion is formed to include a plurality of quadrilateral patterns, and each quadrilateral pattern has four sides. A plurality of ridges extending in parallel with the first side of the pattern are provided, and the ridges are arranged at intervals in a direction parallel to the second side adjacent to the first side, and the directions of the ridges are different from each other. The quadrilateral pattern is arranged so that the first side and the second side are close to each other, and the ridge directions are the same and the first sides of the quadrilateral pattern are adjacent to each other. A quadrilateral region having no ridge is formed.

  As a result, when a crack occurs in the quadrilateral pattern, the crack grows in the long side direction of the quadrilateral pattern along the ridge, but in the decorative portion, the first side of the quadrilateral pattern having a different ridge orientation Since the second side is arranged so as to be close to each other, the crack in the quadrilateral pattern is prevented from growing by the ridges of the other quadrilateral pattern, and the growth of the crack is the first of the quadrilateral pattern at the longest. The length of the side is suppressed. Further, since the decorative portion is formed by arranging quadrilateral patterns with different ridge orientations, at least one of the quadrilateral patterns with different ridge orientations when the outer surface of the sidewall portion is viewed from any direction. Visibility is ensured by. In this case, by arranging the quadrilateral patterns of the decorative portion so as to form a weave pattern, a quadrilateral region having no ridge is arranged between the weaves of each quadrilateral pattern, so the texture pattern is clearly Visible.

  According to the present invention, when a crack occurs in the quadrilateral pattern of the decorative portion, the growth of the crack can be suppressed to the length of the first side of the quadrilateral pattern, so that the deterioration of the tire due to the crack is effective. In addition, the appearance defect due to cracks can be reduced. Moreover, since it is possible to visually recognize at least one of the quadrilateral patterns with different ridge orientations when the outer surface of the sidewall portion is viewed from any direction, the visibility of the decorative portion can be ensured, The decorative effect of the sidewall portion by the decorative portion can be enhanced. In this case, by arranging the quadrilateral patterns of the decorative portion so as to form a texture, it is possible to obtain a unique decorative effect in which the decorative portion looks like a woven fabric, and to clearly visually recognize the texture pattern. And the decoration effect can be further enhanced.

The side view of the pneumatic tire which shows the 1st Embodiment of this invention Partial side view of pneumatic tire Enlarged view of the decoration Enlarged sectional view of the decorative part The partial side view of the pneumatic tire which shows the 2nd Embodiment of this invention Enlarged view of the decoration Cross-sectional view showing test results

  1 to 7 show a first embodiment of the present invention, for example, a pneumatic tire for a passenger car. FIG. 2 shows a part of the side surface of the tire in a straight line, but it is actually an arc.

  The pneumatic tire includes a tread portion 1 formed on the tire outer peripheral surface side, sidewall portions 2 formed on both sides in the tire width direction, and bead portions 3 formed on the tire radial direction inner side of the sidewall portions 2. A plurality of decorative portions 10 extending along the tire circumferential direction are provided on the outer surface of the sidewall portion 2.

  The decorative portion 10 is formed by arranging a plurality of first quadrilateral patterns 11, second quadrilateral patterns 12, and third quadrilateral patterns 13 having different sizes in the tire width direction and the tire radial direction. It is formed integrally with the tire by sulfur molding.

  Each first quadrilateral pattern 11 has an angle formed by the first side A1 and the second side B1 adjacent to each other at 90 °, and the first side A1 is longer than the second side B1. It has a quadrilateral (rectangular shape) and is formed so that the first side A1 has a length of 2 mm or more and 20 mm or less. The first quadrilateral pattern 11 is provided with a plurality of ridges 11a extending in a direction parallel to the first side A1, and each ridge 11a is parallel to the second side B1 of the first quadrilateral pattern 11. Are arranged at intervals.

  Each of the second quadrilateral patterns 12 has a parallel angle of 90 ° between the first side A2 and the second side B2 adjacent to each other, and the first side A2 is shorter than the second side B2. It is a quadrilateral (rectangular), and is formed so that the first side A2 has a length of 2 mm or more and 20 mm or less. In this case, in the second quadrilateral pattern 12, the first side A2 is shorter than the first side A1 of the first quadrilateral pattern 11, and the second side B2 is the first side of the first quadrilateral pattern 11. It is formed to be equal to the side B1 of 2. The second quadrilateral pattern 12 is provided with a plurality of ridges 12a extending in a direction parallel to the first side A2, and each ridge 12a is parallel to the second side B2 of the second quadrilateral pattern 12. Are arranged at intervals.

  Each of the third quadrilateral patterns 13 has a parallel angle of 90 ° between the first side A3 and the second side B3 adjacent to each other, and the first side A3 is longer than the second side B3. It is a quadrilateral (rectangular), and is formed so that the first side A3 has a length of 2 mm or more and 20 mm or less. In this case, the third quadrilateral pattern 13 has a first side A3 shorter than the first side A1 of the first quadrilateral pattern 11 and shorter than the first side A2 of the second quadrilateral pattern 12. It is long and the second side B3 is formed to be equal to the second sides B1 and B2 of the first and second quadrilateral patterns 11 and 12. The third quadrilateral pattern 13 is provided with a plurality of ridges 13a extending in a direction parallel to the first side A3, and each ridge 13a is parallel to the second side B3 of the third quadrilateral pattern 13. Are arranged at intervals.

  The decorative portion 10 has a plurality of ridges that do not have a ridge between the first sides A1, A2, and A3 of the quadrilateral patterns 11, 12, and 13 whose first sides are adjacent to each other in the same ridge direction. The non-patterned quadrilateral region 14 is formed. The quadrilateral region 14 is a parallelogram (square) in which the angle between adjacent sides C is 90 ° and the length of each side C is equal, and the length of each side C is the second quadrangle. The pattern 12 is formed so as to be equal to the first side A2.

  As shown in FIG. 4, each ridge 11a, 12a, 13a is formed of a ridge portion having a quadrangular cross section, and its height H is 0.2 mm or more and 1 mm or less, and a direction parallel to the second sides B1, B2, B3. Is formed such that the interval P of the gap is 0.3 mm or more and 3 mm or less.

  In the decoration part 10, the dimensions of each side of each quadrilateral pattern 11, 12, 13 and the quadrilateral region 14 are formed so as to satisfy the following expressions (1) to (2).

A1>A3> A2 (1)
B1 = B2 = B3 (2)
A1 = 2 x B1 +3 x A2 (3)
A2 = C (4)
A3 = B3 +2 x A2 (5)
In this case, the second and third quadrilateral patterns 12 and 13 having the same orientation of the ridges 12a and 13a and the first quadrilateral pattern 11 having the different orientations of the ridge 11a and the first quadrilateral pattern 1 Between the columns arranged so that the side and the second side are close to each other, the first quadrilateral pattern 11 having the same ridge 11a direction is arranged between the third quadrilateral pattern 13 having the different ridges 13a. As shown in FIG. 2, rows arranged in such a manner that the first side and the second side are close to each other in the horizontal direction are alternately arranged vertically and horizontally with the quadrilateral region 14 in between. Thus, each quadrilateral pattern 11, 12, 13 is arranged so as to form a texture.

  In the pneumatic tire configured as described above, when cracks occur in the decorative portion 10 of the sidewall 1 due to rubber deterioration or external force, the growth of the cracks is caused by the ridges 11a of the quadrilateral patterns 11, 12, and 13, respectively. It is suppressed by 12a and 13a. For example, when a crack occurs in the first quadrilateral pattern 11, the crack grows along the ridge 11 a, but in the decorative portion 10, the first quadrilateral pattern 13 having a different direction of the ridge 13 a is different. Since the side A3 is arranged so as to be close to the second side B1 of the first quadrilateral pattern 11, cracks in the first quadrilateral pattern 11 grow by the ridge 13a of the third quadrilateral pattern 13. Is prevented. Thereby, the growth of cracks is suppressed to the length of the first side A1 of the first quadrilateral pattern 11 at the longest.

  Further, the design of the sidewall portion 2 is enhanced by the decorative portion 10, but the decorative portion 10 includes the second and third quadrilateral patterns 12, 13 in which the ridges 12a, 13a are oriented in the tire radial direction, and the ridge Since the first and second quadrilateral patterns 11 and 13 whose directions 11a and 13a are in the tire circumferential direction are arranged, at least the ridges 12a and 13a in the tire radial direction and the ridges 11a and 13a in the tire circumferential direction are arranged. On the other hand, visibility is ensured, and the brightness and darkness between the decorative portion 10 and other portions are generated when the outer surface of the sidewall portion 2 is viewed from any direction. In this case, since each quadrilateral pattern 11, 12, 13 of the decoration part 10 is arranged so as to form a texture extending vertically and horizontally, a decoration effect that makes the decoration part 10 look like a fabric is obtained, and each of the four sides Since the quadrangular region 14 having no ridge is arranged between the vertical and horizontal rows of the shape patterns 11, 12, and 13, the texture pattern can be clearly recognized.

  Thus, according to the present embodiment, the decorative portion 10 provided on the outer surface of the sidewall portion 2 is formed so as to include a plurality of first, second and third quadrilateral patterns 11, 12, 13. Each quadrilateral pattern 11, 12, 13 is provided with a plurality of ridges 11a, 12a, 13a extending in parallel with the first side of each quadrilateral pattern 11, 12, 13 and each ridge 11a, 12a, 13a. Are arranged at intervals in a direction parallel to the second side adjacent to the first side, and the quadrilateral patterns 11, 12, 13 having different ridges 11a, 12a, 13a in directions are mutually connected to the first side. Between the first sides of the quadrilateral patterns 11, 12, and 13, the ridges 11 a, 12 a, and 13 a are arranged in the same direction and the first sides are adjacent to each other. With ridges 11a, 12a, 13a When the crack is generated in the quadrilateral pattern 11, 12, 13, the growth of the crack is suppressed to the length of the first side of the quadrilateral pattern 11, 12, 13. Can do. Thereby, while being able to suppress effectively deterioration of the tire by a crack, the appearance defect by a crack can also be reduced.

  Further, since the decorative portion 10 is formed by arranging quadrilateral patterns 11, 12, 13 in which the directions of the ridges 11a, 12a, 13a are different, the ridge 11a, At least one of the quadrilateral patterns 11, 12, and 13 in which the directions of 12a and 13a are different can be visually recognized, and the visibility of the decorative portion 10 can be sufficiently ensured.

  In this case, by arranging the quadrilateral patterns 11, 12, and 13 of the decorative portion 10 so as to form a texture extending vertically and horizontally, a unique decorative effect that makes the decorative portion 10 look like a woven fabric is obtained. Since the quadrilateral region 14 having no ridge is arranged between the column and the row of the quadrilateral patterns 11, 12, and 13, the texture pattern can be clearly seen and the decoration effect can be further enhanced. .

  Further, since the quadrilateral region 14 is formed without a pattern, the texture patterns of the quadrilateral patterns 11, 12, and 13 can be made more conspicuous, which is extremely effective in improving the decoration effect.

  Furthermore, since the length of the first side A1, A2, A3 of each quadrilateral pattern 11, 12, 13 is set to 2 mm or more and 20 mm or less, the length of the first side A1, A2, A3 is too short. There is no deterioration in workability due to an increase in the number of the shape patterns 11, 12, 13 and the length of the first sides A1, A2, A3 is too long, and the effect of suppressing cracks may be reduced. There is no advantage.

  In addition, since the height H of the ridges 11a, 12a, 13a of each quadrilateral pattern 11, 12, 13 is set to 0.2 mm or more and 1 mm or less, the height of the ridges 11a, 12a, 13a is too low, and the crack suppressing effect. Is not lowered, and there is an advantage that a molding defect at the time of vulcanization molding due to the height of the ridges 11a, 12a, 13a being too high does not occur.

  Furthermore, since the interval P between the ridges 11a, 12a, 13a in the direction parallel to the second side of each quadrilateral pattern 11, 12, 13 is set to 0.3 mm or more and 3 mm or less, the interval between the ridges 11a, 12a, 13a is There is no deterioration in workability due to being too small, and the interval between the ridges 11a, 12a, 13a is too large, and the decorative effect of the quadrilateral patterns 11, 12, 13 due to the brightness of the ridges 11a, 12a, 13a is reduced. There is an advantage that there is nothing.

  Further, since the quadrilateral region 14 is formed so that the length of one side is 1 mm or more and 5 mm or less, the quadrilateral region 14 is not too small and the visibility of the decorative portion 10 is not lowered. Has an advantage that the crack suppression effect is not lowered due to being too large.

  In the first embodiment, the decorative portion 10 is formed by the first, second and third quadrilateral patterns 11, 12, 13 and the quadrilateral region 14 having different first side lengths. However, for example, as in the second embodiment shown in FIGS. 5 and 6, the decorative portion 20 is formed by the first and second quadrilateral patterns 11 and 12 and the quadrilateral region 14. You may do it. In this case, in the second embodiment, the first and second quadrilateral patterns 11 and 12 having the same orientation of the ridges 11a and 12a are arranged with the first quadrilateral pattern 11 having the different orientations of the ridge 11a in between. By arranging the columns and rows arranged so that the first side and the second side are close to each other in the vertical direction alternately in the vertical and horizontal directions with the quadrilateral region 14 in between, FIG. As shown, the quadrilateral patterns 11, 12, 13 are arranged so as to form a texture.

  About Example 1-6 of this invention and the conventional example, when the crack growth-proof property and the visibility of the decoration part were tested, the result shown in FIG. 7 was obtained.

  In the conventional example, one having no decorative portion in the sidewall portion was used, and in Examples 1 to 5, the decorative portion was formed by a quadrilateral pattern having different ridge directions. In this case, in Examples 1, 3, 5 and 6, the angle θ formed by the first side and the second side of the quadrilateral pattern is 90 °, and in Example 2, the first side of the quadrilateral pattern And the second side has an acute angle θ of 45 °, and the fourth embodiment uses an acute angle angle θ of 45 ° formed by the first side and the second side of the quadrilateral pattern. It was. In this test, the first side length A1 and the second side length B1 of the first quadrilateral pattern of Examples 1 to 6 are set, but these lengths A1 and B1 are set. Is determined, the lengths of the other lengths A2, B2, A3, B3, and C can be obtained by the above equations (1) to (5).

In the crack growth resistance test, tires having a tire size of 205 / 55R16 were used. In addition, the crack growth resistance was evaluated by applying an air pressure of 100 kPA, a speed of 80 km / h, a load of 4.5 kN, and irradiating ozone with a concentration of 100 pphm from a position 10 mm away from the outer surface of the sidewall. The length of the crack after the lapse of time was evaluated. If any crack of 15 mm or more has occurred, the evaluation is 100, and if any crack of 6 to 14 mm has occurred, the evaluation is 101 to 115, and even one crack of 5 mm or less has occurred. If the crack length is less than 5 mm, the evaluation was 116 to 130.

  In the visibility test, we examined whether or not the decorative part could be visually recognized when 20 people's monitors stood and viewed each at a position 1 m away in a direction inclined 45 ° to the left with respect to the tire width direction. Aggregated and indexed. The higher the index, the better the visibility.

  As a result of the test, it was found that Examples 1 to 6 were superior in crack growth resistance and visibility to the conventional example.

  2 ... sidewall portion, 10 ... decoration portion, 11 ... first quadrilateral pattern, 11a ... ridge, 12 ... second quadrilateral pattern, 12a ... ridge, 13 ... third quadrilateral pattern, 13a ... ridge, 14 ... quadrilateral region, 20 ... decoration part.

Claims (7)

In a pneumatic tire having a decorative portion on the outer surface of the sidewall portion,
Forming the decorative part to include a plurality of quadrilateral patterns;
Each quadrilateral pattern is provided with a plurality of ridges extending in parallel with the first side of the quadrilateral pattern, and the ridges are arranged at intervals in a direction parallel to the second side adjacent to the first side. ,
Arranging the quadrilateral patterns with different ridge orientations so that the first side and the second side are close to each other,
A pneumatic tire characterized in that a quadrilateral region having no ridge is formed between first sides of a quadrilateral pattern in which the directions of ridges are the same and the first sides are adjacent to each other. 2. The pneumatic tire according to claim 1, wherein the decorative portion is formed such that a quadrilateral pattern having different ridge orientations forms a texture. The pneumatic tire according to claim 1 or 2, wherein the quadrilateral region is formed without a pattern. The pneumatic tire according to claim 1, 2, or 3, wherein the quadrilateral pattern is formed such that the length of the first side is 2 mm or more and 20 mm or less. The pneumatic according to claim 1, 2, 3, or 4, wherein the quadrilateral pattern is formed by a parallelogram whose acute angle formed by the first side and the second side is 45 ° or more. tire. The pneumatic tire according to claim 1, 2, 3, 4, or 5, wherein the quadrilateral pattern is formed so that a ridge has a height of 0.2 mm to 1 mm. The pneumatic tire according to claim 1, 2, 3, 4, 5 or 6, wherein the quadrilateral region is formed so that one side has a length of 1 mm to 5 mm.

Images