Pneumatic tire having turbulence generating protrusions provided inside a groove

Patent metadata

Field	Value
Publication number	US-9266398-B2
Application number	US-52638408-A
Country	US
Kind code	B2
Filing date	Feb 8, 2008
Priority date	Feb 9, 2007
Publication date	Feb 23, 2016
Grant date	Feb 23, 2016

Abstract

A pneumatic tire 1 according to the present invention has turbulence generating protrusions on a tire surface, each of the turbulence generating protrusions having a sharp edge part. In the pneumatic tire, the following relationships are satisfied: 0.015≦H/√R≦0.64; 1.0≦p/H≦50.0; 0.1≦H/e≦3.0; 1.0≦L/H≦50.0; and 1.0≦(p−w)/w≦100.0, where “R” is a tire radius, “H” is a protrusion maximum height, “p” is a protrusion circumferential-direction interval, “e” is a protrusion radial-direction interval, “L” is a protrusion radial-direction length, and “w” is a protrusion circumferential-direction length.

First claim

The invention claimed is:

1. A pneumatic tire comprising turbulence generating protrusions on a tire surface, each of the turbulence generating protrusions having a sharp edge part, wherein the following relationships are satisfied:
0.5 mm<H≦5 mm;
0.03≦H/√R≦0.64;
1.0≦p/H≦50.0;
0.1≦H/e≦3.0;
1.0≦L/H≦50.0; and
1.5≦(p−w)/w≦100.0, where
“R” is a tire radius being a distance from a rim center to an outermost position in a tread radial direction,
“H” is a protrusion maximum height being a distance from the tire surface to a position at which each turbulence generating protrusion protrudes farthest from the tire surface,
“p” is a protrusion circumferential-direction interval being an interval between the turbulence generating protrusions adjacent in a tire rotation direction,
“e” is a protrusion radial-direction interval being an interval between the turbulence generating protrusions adjacent in a rotation orthogonal direction substantially orthogonal to the tire rotation direction,
“L” is a protrusion radial-direction length being a maximum length of each turbulence generation protrusion in the rotation orthogonal direction, and
“w” is a protrusion circumferential-direction length being a maximum length of each turbulence generation protrusion in the tire rotation direction,
wherein the turbulence generating protrusions are provided inside a groove on the tire surface.

2. The pneumatic tire according to claim 1 , wherein
an average arrangement density (ρ) of the turbulence generating protrusions is 0.0008 to 13 pieces/cm2.

3. The pneumatic tire according to claim 2 , wherein
the average arrangement density (ρ) of the turbulence generating protrusions decreases gradually from an inner side in a tire radial direction toward an outer side in the tire radial direction.

4. The pneumatic tire according to claim 1 , wherein
the turbulence generating protrusions are arranged at predetermined intervals in respective directions: a direction in which the turbulence is generated to flow in a direction opposite to the tire rotation direction; and a direction orthogonal to the turbulence, and are arranged in a staggered manner in which the turbulence generating protrusions adjacent in the turbulence generation direction are arranged at respective positions shifted from each other.

5. The pneumatic tire according to claim 4 , wherein
a protrusion circumferential-direction center line (CL′) inclines relative to the tire rotation direction by 10° to 20°, towards a rear side thereof in the tire rotation direction being outward in the tire radial direction, from a front side thereof in the tire rotation direction, and
the protrusion circumferential-direction center line (CL′) being a line that connects centers of the respective turbulence generating protrusions adjacent in the tire rotation direction.

6. The pneumatic tire according to claim 1 , wherein
in a protrusion top view being a view in which the turbulence generating protrusion is viewed from top, a front face of the turbulence generating protrusion curves at least partially, the front face being located frontward, in the tire rotation direction, of a protrusion radial-direction center line (CL), and
a front angle (θ 1 ) and a rear angle (θ 2 ) are each set to a value between 45° and 135°, inclusive,
the front angle (θ 1 ) being an angle formed between the tire surface and the front face,
the rear angle (θ 2 ) being an angle formed between the tire surface and a rear face located rearward, in the tire rotation direction, of the protrusion radial-direction center line (CL).

7. The pneumatic tire according to claim 1 , wherein in a protrusion top view being a view in which each turbulence generating protrusion is viewed from top, a front convex part is provided frontward, in the tire rotation direction, of protrusion radial-direction center line (CL), the front convex part protruding frontward in the tire rotation direction.

8. The pneumatic tire according to claim 1 , wherein
in a protrusion top view being a view in which each turbulence generating protrusion is viewed from top, a front face located frontward, in the tire rotation direction, of protrusion radial-direction center line (CL) has a front inner point (Q 1 ) located at an innermost position in a tire radial direction, and a front outer point (Q 2 ) located at an outermost position in the tire radial direction,
the front inner point (Q 1 ) being located frontward, in the tire rotation direction, of the front outer point (Q 2 ).

9. The pneumatic tire according to claim 1 , wherein
in a protrusion top view being a view in which each turbulence generating protrusion is viewed from top, at least one of a rear convex part and a rear concave part is provided rearward, in the tire rotation direction, of protrusion radial-direction center line (CL),
the rear convex part protruding rearward in the tire rotation direction, the rear concave part being concave frontward in the tire rotation direction.

10. The pneumatic tire according to claim 1 , wherein
an inner angle (θ 3 ) and an outer angle (θ 4 ) are each set to a value between 45° and 135°, inclusive, the inner angle (θ 3 ) being an angle formed between the tire surface and an inner face located at an innermost position in a tire radial direction, the outer angle (θ 4 ) being an angle formed between the tire surface and an outer face located at an outermost position in the tire radial direction.

11. The pneumatic tire according to claim 1 , wherein
a front maximum angle (θ 5 ) and a rear maximum angle (θ 6 ) are each set to a value between 45° and 135°, inclusive,
the front maximum angle (θ 5 ) being an angle formed between a most-protruded position and a position where the tire surface intersects with a front face located frontward, in the tire rotation direction, of protrusion radial-direction center line (CL), the most-protruded position protruding farthest from the tire surface,
the rear maximum angle (θ 6 ) being an angle formed between the most-protruded position and a position where the tire surface intersects with a rear face located rearward, in the tire rotation direction, of protrusion radial-direction center line (CL).

12. The pneumatic tire according to claim 1 , wherein an inner maximum angle (θ 7 ) and an outer maximum angle (θ 8 ) are each set to a value between 45° and 135°, inclusive,
the inner maximum angle (θ 7 ) being an angle formed between a most-protruded position and a position where the tire surface intersects with an inner part located at an innermost position in a tire radial direction,
the most-protruded position protruding farthest from the tire surface, the outer maximum angle (θ 8 ) being an angle formed between the most-protruded position and a position where the tire surface intersects with an outer part located at an outermost position in the tire radial direction.

13. The pneumatic tire according to claim 1 , wherein the following relationship is satisfied:
0.1≦H/√R≦0.64.

14. The pneumatic tire according to claim 1 , wherein the turbulence generating protrusions are also provided on sidewalls.

15. The pneumatic tire according to claim 1 , wherein the following relationship is satisfied:
2 mm≦L≦15 mm.

16. The pneumatic tire according to claim 1 , the turbulence generating protrusions are also provided on sidewalls and sidewall reinforcing layers, formed in a crescent-shape in the cross section, are formed inward in a tread width direction of a carcass layer.

17. The pneumatic tire according to claim 1 , wherein the following relationship is satisfied:
0.

Assignees

• Yamaguchi Masashi
• Bridgestone Corp

Inventors

• Yamaguchi Masashi

Classifications

• B60C2013/026

  provided at the interior side only · CPC title

• B60C11/042

  further characterised by the groove cross-section · CPC title

• B60C11/01

  Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered · CPC title

• B60C17/0045

  comprising grooves or ribs, e.g. at the inner side of the insert · CPC title

• B60C2011/1361

  with protrusions extending from the groove bottom · CPC title