JP6197337B2 - Pneumatic tire - Google Patents

Description

  The present invention relates to a pneumatic tire, and more particularly to a pneumatic tire that achieves both good riding comfort and excellent rim protection.

  In order to prevent the rim flange from being damaged when the vehicle is brought to the road shoulder (curbstone) or over the cat's eye, a rim protection bar may be provided on the low flat tire and the low section tire. Many have been adopted.

  However, the provision of the rim protection bar has an advantage that the rim flange can be protected, but there is also a demerit that the ride comfort deteriorates due to an increase in tire weight and an increase in side rigidity due to its arrangement and shape.

  Various studies have been made on pneumatic tires that can eliminate such disadvantages while taking advantage of such rim protection bars.

  For example, as a pneumatic tire that is lightweight and capable of preventing damage to the rim flange, a rim protect provided on the outer side in the axial direction of the sidewall is provided, and the rim protect has a large number of blocks arranged in the tire circumferential direction. An entering tire has been proposed (Patent Document 1).

  In addition, as a pneumatic tire that has improved curb resistance while suppressing an increase in tire weight, the width on the tire outer wall side extending in the tire circumferential direction along the tire cross-section maximum width position of the sidewall portion is 10 mm or more and 50 mm. A protector comprising a trapezoidal or rectangular land portion having a cross section of 1 mm or more and 5 mm or less in height is provided, and the land portion has a width of 2 mm or less, 0.2 mm or more, and a depth d of 1 mm or more and 5 mm. There has been proposed a pneumatic tire in which the following plurality of slit-shaped notch grooves 3 are formed at substantially equal intervals over the entire circumference of the tire so that the angle with respect to the tire circumferential direction is 10 to 90 ° (Patent Document 2).

  However, these proposals have room for further improvement in terms of the reduction in weight (lightening) due to the provision of a rim protection bar and the compatibility between ride comfort and excellent rim protection. It was

JP 2011-20621 A JP 2006-213128 A

  The object of the present invention is to ensure the protection performance of the rim flange by effectively arranging the rim protection bar in the curb entry direction and specifying the shape of the rim protection bar in view of the above points. In addition, it is an object of the present invention to provide a pneumatic tire having a rim protect bar that suppresses deterioration in ride comfort.

The pneumatic tire of the present invention that achieves the above-described object has the following configuration (1).
(1) A tire for which the rotation direction is specified, and there is a rim protection convex portion in the range of 10% or more and 40% or less near the tire rotation axis when the tire cross-sectional height of the tire side portion is 100%. The protrusions are intermittently arranged in the tire circumferential direction, and each protrusion has a line segment connecting two points so as to have the maximum length on the projection surface, and is radially from the tire center. When the line segment in the range where the extending straight line extends is B, and the vertical line with respect to the line segment B at the intersection of A and B is C, the angle θ formed by A and C starts from C toward the tire rotation direction. in the range of 35 ° or more 55 ° or less Te pneumatic tire characterized by greater in line a than the segment B on the convex portion.

  Such a pneumatic tire of the present invention preferably has any of the following configurations (2) to (10).

(2) The pneumatic tire according to (1), wherein a maximum thickness D from the profile surface of the convex portion is larger than an interval G between the convex portions.
(3) The pneumatic tire according to (1) or (2), wherein a maximum thickness D from the profile surface of the convex portion is larger than a tire radial direction cross-sectional width W of the convex portion.
(4) The air according to any one of (1) to (3), wherein the length of the line segment A is not less than twice the length of the line segment B in the convex portion. Enter tire.
(5) The pneumatic tire according to (4), wherein the convex portion overlaps an adjacent convex portion with respect to a tire radial direction.
(6) The convex portion is connected to at least a partial region of the convex portion adjacent to at least a partial region of the convex portion, according to any one of the above (1) to (5) Pneumatic tire.

(7) The pneumatic tire according to any one of the above (1) to (6), wherein a maximum thickness D in the cross-sectional direction of the convex portion for rim protection is 3 mm or more and 30 mm or less from a profile line.
(8) The pneumatic tire according to any one of the above (1) to (7), wherein a tire radial direction cross-sectional width W of the rim protection convex portion is 3 mm or more and 15 mm or less.
(9) The pneumatic tire according to any one of the above (1) to (8), wherein an interval G between the adjacent rim protection convex portions is 1 mm or more and 10 mm or less at the shortest portion.
(10) the rim protection protrusion is with respect to the normal to the tire profile lines, any of the above, characterized in that it is disposed inclined in a range of 4 5 ° or less (1) - (9) Pneumatic tire described in 2.

  According to the pneumatic tire of the present invention according to claim 1, the rim protect bar is effectively arranged in the curb entry direction, and the shape of the rim protect bar is specified to thereby improve the protection performance of the rim flange. Provided is a pneumatic tire that is secured and suppresses deterioration in ride comfort.

  In particular, according to the pneumatic tire of the present invention according to any one of claims 2 to 10, the book having the above-described effects of the pneumatic tire of the present invention according to claim 1 more clearly and effectively. An inventive pneumatic tire is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure explaining the pneumatic tire of this invention, (a) is tire meridian direction sectional drawing explaining the position which provides a rim protect bar, (b) is a tire explaining one example of a rim protect bar. It is the principal part enlarged view which showed the shape which projected the rim protect bar from the rotating shaft direction, and the example of arrangement | positioning. It is a model figure for demonstrating the curb approach angle (theta) in the pneumatic tire of this invention. It is a model figure for demonstrating the preferable relationship of the maximum thickness D from the profile surface of the convex part for rim protection in the pneumatic tire of this invention, and the space | interval G between convex parts. (A)-(c) projected the relationship with the line segment A, the line segment B, and the perpendicular line C about the rim protection convex part of the example of various aspects in the pneumatic tire of this invention. It is a model figure demonstrated combining with a shape. (A)-(c) is a model figure explaining the example of various aspects regarding the overlap of the convex part for adjacent rim protection in the pneumatic tire of this invention. FIG. 5 is a model diagram showing a form in which each of the rim protection convex portions in the pneumatic tire of the present invention is connected to adjacent rim protection convex portions by a partial region on the bottom side. It is the model figure which showed one preferable example of the convex part for rim protection in the pneumatic tire of this invention.

  Hereinafter, the pneumatic tire of the present invention will be described in more detail.

  As shown in FIG. 1A, the pneumatic tire of the present invention is a tire 1 in which the tire rotation direction R is designated, and the tire cross-section height H of the tire side portion 2 is 100%. A rim protection convex portion 3 is provided in a region Z having a height within a range of 10% to 40% near the tire rotation axis. As shown in FIG. 1B, the convex portion is in the tire circumferential direction. It is arranged intermittently.

  Then, as shown in FIG. 1B, each of the convex portions extends in the radial direction from the tire center with A being a line segment connecting two points so as to have the maximum length on the projection plane. A straight line (when the line segment in the range extending to the center point of the projected figure of the convex portion is B, when the vertical line to the line segment B at the intersection P of the line segments A and B is C, the line segment A and The angle θ formed by the vertical line C (from the vertical line C as a starting point) is in the range of 0 ° to 55 ° in the same direction as the tire rotation direction D, and the line segment is more than the line segment B on the convex portion. A is larger (longer).

The above-described relationship will be described in detail. As shown in FIG. 2, the angle θ is determined from the tire center at the center line position where the tire radius is Rjdia, the height of the curb 4 is h, and the rim protect 3 is provided. When the radius is Rrim, it is defined by the following equation (a).
θ = cos ⁻¹ ((Rjdia−h) / Rrim)

  This angle θ should be the curb entry angle that enters toward the curb tire. The angle θ is in the range of 0 ° to 55 °, and the line segment A is more than the line segment B on the convex portion. By configuring so that is larger (longer), the rigidity of the convex part with respect to the curb entry direction can be secured, so that the rim protection performance is not impaired, while the other direction (for example, tire diameter) Since the rigidity can be reduced with respect to (direction), it is possible to prevent the ride comfort from being deteriorated by providing a rim protector.

  The preferable range of θ is in the direction in which the above-described effect becomes smaller as it approaches 0 °, and is preferably in the range of 35 to 55 °.

  In the present invention, as shown in FIG. 3, the maximum thickness D from the profile surface of the convex portion 3 is preferably larger than the gap G between the convex portions 3. This is because the rim protection performance can be further increased, and more preferably, the maximum thickness D is at least twice the gap G between the convex portions 3 in order to further increase the rim protection performance. Moreover, it is preferable that the maximum thickness D from the profile surface of the convex part 3 is larger than the cross-sectional width W of the convex part 3 in the tire radial direction. This is because the rim protection performance can be further increased, and more preferably, the maximum thickness D is not less than three times the cross-sectional width W of the convex portion 3 in the tire radial direction in order to further increase the rim protection performance. is there.

  In order to clearly obtain the effect of the present invention, it is preferable that the length of the line segment A in the convex portion 3 is twice or more than the length of the line segment B.

  Furthermore, the projection 3 has a parallelogram shape, a wave shape, a kamaboko shape, etc. as shown in FIGS. 4A to 4C in addition to the elliptical shape shown in FIG. It may be. In any case, the length of the line segment A is preferably at least twice as long as the length of the line segment B.

  Moreover, it is preferable that the convex part 3 whose length of said line segment A is 2 times or more with respect to the length of the line segment B overlaps with the adjacent convex part 3 in a tire radial direction. By configuring in this way, more protrusions 3 can be arranged in the circumferential direction without reducing the size of the protrusions, and the protrusions 3 support each other at the time of curb contact, Higher rim protection performance can be demonstrated. In other words, the larger the number of convex portions in the circumferential direction, the more the curb entry angle (the shape in which the convex portions effectively contact the curb) can be secured when viewed around the tire, and the rim protection performance is improved. .

  This relationship will be described with reference to the model diagrams shown in FIGS. 5A to 5C. FIG. 5A shows an aspect in which the convex portions are large and the number of convex portions in the circumferential direction is large. Because they support each other, the rim protection performance is great and the ride comfort is good. In FIG. 5A, a portion (area) supported by the convex portions is depicted as a rectangle in a model manner. In (b), although the convex portions are large, the number of convex portions in the circumferential direction is small, the rim protection performance is medium, and the riding comfort is good. In (c), although the convex portions are small, the number of convex portions in the circumferential direction is large and the rim protection performance is medium, and the ride comfort is good.

  Moreover, it is preferable that the said convex part is connected with the partial area | region of the convex part which at least the partial area | region of this convex part 3 adjoins with the bottom part side mutually. FIG. 6 is a model diagram showing the form, which is the same as that shown in FIG. 3 except that the convex portions 3 are connected to each other by the adjacent convex portion 3 and the partial region 5 on the bottom side. The form which is done is shown. By configuring in this way, it is possible to improve the rim protection while minimizing the deterioration of ride comfort. The preferable thickness d of the partial region is in the range of 0.1 to 0.5 times the maximum thickness D from the profile surface of the convex portion 3. When larger than 0.5 times, it is a direction where the effect of providing the convex part 3 intermittently becomes scarce, and the riding comfort is lowered.

  Further, the maximum thickness D (FIG. 3) from the profile surface of the rim protection convex portion 3 is preferably 3 mm or more and 30 mm or less from the profile line. This is because the rim protection performance can be surely exhibited, and more preferably 4 to 10 mm.

  Moreover, it is preferable that the tire cross-sectional width (radial direction) W (FIG. 3) of the rim protection convex portion 3 is 3 mm or more and 15 mm or less. This is because the rim protection performance can be surely exhibited.

  Furthermore, it is preferable that the gap G (FIG. 3) between adjacent rim protection convex portions is 1 mm or more and 10 mm or less at the shortest portion. This is to ensure that the rim protection performance is exhibited.

  Further, as shown in FIG. 7, it is also preferable that the rim protection convex portion 3 is disposed so as to be inclined in the range of 0 ° to 45 ° with respect to the normal to the tire profile line. With this configuration, the convex portion is inclined with respect to the curb entry direction (for example, laid in the reverse direction), whereby breakage of the convex portion and the like can be favorably prevented.

  The material constituting the rim protection convex portion 3 does not need to be a special material, and may be a conventionally used material.

EXAMPLES 1-6, COMPARATIVE EXAMPLES 1-2, CONVENTIONAL EXAMPLE Hereinafter, the pneumatic tire of this invention is demonstrated by an Example.

  225 / 45R17 was used as a test tire for each of the examples and comparative examples, which were attached to a JATMA standard rim 17 × 6.5JJ, and the tire internal pressure was set to 180 kPa. The test vehicle was a sedan vehicle with a displacement of 2.0 liters.

  The tire outer diameter was 634 mm, the rim protect outer diameter was 496 mm, the curb height was 150 mm, and the ride comfort and rim protect performance were tested. The curb entry angle θ was set to three types: −5 ° (Comparative Example 1), 47 ° (Examples 1 to 6), and 70 ° (Comparative Example 2). Conventional example 1 is one in which rim protection is continuously provided in a band shape. The details of the shape of the other protrusions are as described in Table 1.

  Each test tire was evaluated for ride comfort and rim protection performance. The standard of evaluation is that 225 / 45R17, which is a general size having a rim protection convex part, was tested at the standard air pressure of the vehicle. As an evaluation, an average value of n number 3 was calculated and used as the score of the test tire. The larger the score, the better.

  As can be seen from Table 1, the pneumatic tire according to the present invention is excellent in both ride comfort and rim protection performance.

1: Tire 2: Tire side part 3: Rim protect (Rim protect convex part)
4: Curb 5: Partial region where adjacent convex portions are connected on the bottom side θ: Curb entry angle R: Tire rotation direction (specified direction)
D: Maximum thickness in the cross-sectional direction of the rim protection convex portion G: Distance between adjacent rim protection convex portions W: Tire cross-sectional width of the rim protective convex portion (radial direction)

Claims (10)

There is a rim protection convex portion in the range of 10% or more and 40% or less near the tire rotation axis when the tire has a specified rotational direction and the tire cross-section height of the tire side portion is 100%. The part is intermittently arranged in the tire circumferential direction, and each convex part has a line segment connecting two points so as to have the maximum length on the projection plane, and a straight line extending in the radial direction from the tire center Assuming that the range of the line segment is B, and the vertical line with respect to the line segment B at the intersection of A and B is C, the angle θ formed by A and C is 35 ° toward the tire rotation direction starting from C. or in the range of 55 ° or less, pneumatic tire characterized by greater in line a than the segment B on the convex portion.   The pneumatic tire according to claim 1, wherein a maximum thickness D from the profile surface of the convex portion is larger than a gap G between the convex portions.   The pneumatic tire according to claim 1 or 2, wherein a maximum thickness D from the profile surface of the convex portion is larger than a tire radial direction cross-sectional width W of the convex portion.   The pneumatic tire according to any one of claims 1 to 3, wherein in the convex portion, the length of the line segment A is not less than twice the length of the line segment B.   The pneumatic tire according to claim 4, wherein the convex portion overlaps the adjacent convex portion with respect to the tire radial direction.   The pneumatic tire according to claim 1, wherein the convex portion is connected to at least a partial region of the convex portion adjacent to at least a partial region of the convex portion.   The pneumatic tire according to any one of claims 1 to 6, wherein a maximum thickness D in the cross-sectional direction of the convex portion for rim protection is 3 mm or more and 30 mm or less from a profile line. The pneumatic tire according to any one of claims 1 to 7, wherein a cross-sectional width W of the rim protection convex portion in a tire radial direction is 3 mm or more and 15 mm or less.   The pneumatic tire according to any one of claims 1 to 8, wherein a distance G between adjacent rim protection convex portions is 1 mm or more and 10 mm or less at the shortest portion. It said rim protection protrusion is pneumatic tire according to any one of claims 1 to 9 to the normal to the tire profile line, characterized in that it is disposed inclined in a range of 4 5 ° or less .

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