Bridgestone Corporation

Shintaro Hatanaka

Isao Kuwayama

Hiroyuki Matsumoto

Kentaro Kozuki

Jun Watanabe

Yasuo Ohsawa

Shingo Hiura

A pneumatic radial tire for passenger vehicles that satisfies a defined relationship between sectional width SW and outer diameter OD of the tire, and includes only two circumferential main grooves extending in a tire circumferential direction on a tread contact surface, a barycenter of the circumferential main grooves being positioned in a half portion of the tire on a vehicle-mounted outward side, which is one side of the tire in a tread width direction with a tire equatorial plane as a boundary. A drop height (or ground contact length relationship, or tread gauge relationship) is also defined.

Pneumatic radial tire for passenger vehicles

A pneumatic radial tire for passenger vehicles that satisfies a defined relationship between sectional width SW and outer diameter OD of the tire, and includes only two circumferential main grooves extending in a tire circumferential direction on a tread contact surface, a barycenter of the circumferential main grooves being provided to a half portion of the tire on a vehicle-mounted inward side, which is one side of the tire in a tread width direction with a tire equatorial plane as a boundary. A drop height (or ground contact length relationship, or tread gauge relationship) is also defined.

A method of measuring a height of water on ice of the present disclosure comprises emitting terahertz radiation having a frequency of 10 THz or less toward a first surface of the ice; and measuring transmitted or reflected radiation of the terahertz radiation to measure the height of the water on the ice from a result of the measurement.

Method of measuring height of water on ice

The pneumatic tire includes, on a tread surface, at least two circumferential main grooves and at least one rib-like land portion defined by two of the circumferential main grooves. The rib-like land portion includes neither grooves nor sipes that extend to include a widthwise center line of the rib-like land portion. The rib-like land portion includes a one-end-open sipe and a both-end-closed sipe. The one-end-open sipe has a widthwise sipe portion and a circumferential sipe portion, the widthwise sipe portion extending in tire width direction from one end of the one-end-open sipe and being terminated within the rib-like land portion, and the circumferential sipe portion being located closer to the widthwise center line than the both-end-closed sipe, extending in tire circumferential direction from the widthwise sipe portion, and being terminated at another end of the one-end-open sipe.

Pneumatic tire

A pneumatic tire comprises, in a tread surface: at least two circumferential main grooves continuously extending in a tire circumferential direction; and at least one rib-like land portion each defined by two adjacent circumferential main grooves from among the at least two circumferential main grooves. The rib-like land portion has: a circumferential sipe including a circumferential sipe portion extending in the tire circumferential direction; and a both-end closed sipe having both ends terminating within the rib-like land portion. When a land portion width of the rib-like land portion is evenly divided by three where a region at a center in a tire width direction is a center region and regions on both sides of the center region in the tire width direction are side regions, the circumferential sipe portion is located only in the center region, and the both-end closed sipe is located in any of the side regions.

When a tire is attached to a rim and set to an internal pressure of 250 kPa or more, a ratio SW/OD of the tire is 0.26 or less in the case where SW of the tire is less than 165 (mm), and SW and OD satisfy a relationship 2.135&#xd7;SW+282.3&#x2264;OD in the case where SW is 165 (mm) or more. The tread rubber has dynamic storage modulus E' of 6.0 MPa to 12.0 MPa, and loss tangent tan &#x3b4; of 0.05 to 0.15. In at least one land portion, sipes are arranged with a predetermined pitch length L, and a land portion width W, a tire widthwise sipe component total length Ws of the sipes, the pitch length L, and a tire circumferential sipe component total length Ls of the sipes satisfy relationships 0.4W&#x2264;Ws&#x2264;1.2W and 0.6L&#x2264;Ls&#x2264;3L.

Passenger vehicle pneumatic radial tire

A pneumatic radial tire for a passenger vehicle according to the present invention has an appropriate relationship between a tire cross-sectional width SW and a tire outer diameter OD. Also, a method of using the pneumatic radial tire for a passenger vehicle according to the present invention is to use the above radial tire with at least specified internal pressure.

Pneumatic radial tire for a passenger vehicle and method of using the same

To reduce noise while suppressing increase in rolling resistance, without affecting the formation of a carcass line, provided is a pneumatic tirecomprising an inner liner. The thickness of the inner linerat least in part of a side portionis 1.5 mm or more. When the tireis mounted to a rim, and an internal pressure of 250 kPa or more is applied to the tire, in a case where a sectional width SW of the tire is less than 165 mm, a ratio of the sectional width SW to an outer diameter OD of the tire, SW/OD, is 0.26 or less; and in a case where the sectional width SW of the tire is 165 mm or more, the sectional width SW and the outer diameter OD of the tire satisfy a relation expression OD&#x2265;2.135&#xd7;SW+282.3.

The present invention provides: a pneumatic radial tire for a passenger car, the tire having cross sectional width SW and outer diameter OD satisfying a predetermined relationship formula when the tire is assembled with a rim and inflated at internal pressure of at least 250 kPa; a tire-rim assembly formed by assembling bead portions of said tire with the rim; and a method for using a tire, including preparing a pneumatic radial tire for a passenger car in which cross sectional width SW and outer diameter OD of the tire satisfy a predetermined relationship formula, and using the tire at internal pressure of at least 250 kPa.

Pneumatic radial tire for passenger vehicle, method for using the tire, and tire-rim assembly including the tire

An object of the present invention is to adequately control relationship between a cross sectional width SW and an outer diameter OD of a pneumatic radial tire for a passenger vehicle. The tire is further characterized in that, provided that each half portion in the tire width direction of a ground contact surface of the tire is divided in the tire width direction into three equal portions including a tire-width-direction center portion, a tire-width-direction intermediate portion and a tire-width-direction outer portion from the tire-width-direction center side, rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to the tire-width-direction outer side portion is lower than rigidity in the tire circumferential direction of the belt reinforcing layer in a region in the tire width direction thereof corresponding to the tire-width-direction center portion.

Pneumatic radial tire for passenger vehicle

Provided is a pneumatic radial tire for a passenger vehicle, having a carcass constituted of plies as radially-disposed cords and toroidally provided across a pair of bead portions, and including: a belt constituted of one or more belt layers; and a tread, which are disposed in this order on the outside in the radial direction of the carcass, in which: a section width SW and an outer diameter OD of the tire have a ratio of SW/OD&#x2264;0.26 when SW&#x3c;165 (mm), and SW and OD satisfy a relationship formula OD&#x2265;2.035&#xd7;SW+282.3 when SW&#x2265;165 (mm); and provided that V1 represents a volume of rubber lying inside in the tire width direction than the both ends in the width direction of a maximum-width belt layer having a maximum width in the tire width direction among the belt layers while lying outside in the tire radial direction than the reinforcing member which is the outermost layer of the belt layers in the tire radial direction at the center position in the tire width direction, and that V2 represents a total volume of all the grooves formed in a surface of the tread, V1 and V2 has a ratio V2/V1&#x2264;20%.

Pneumatic radial tire for a passenger vehicle and method of using the tire

A pneumatic tire that makes steering stability, rolling resistance performance, and noise performance compatible includes a carcass toroidally extending between two bead portions; an inclined belt, with inclined belt layer(s) including cords that extend at an inclination relative to a tire circumferential direction, and a circumferential belt, with circumferential belt layer(s) including cords that extend along the tire circumferential direction, radially at an outer side of a crown portion of the carcass; and a tread at an outer side of the circumferential belt in the tire radial direction. An inclination angle of the cords in the inclined belt layers is 35&#xb0; to 90&#xb0;, the circumferential belt has a higher tire circumferential direction rigidity per unit width in a central region including a tire equator than in other regions, and in a surface region including the tire equator, the tread includes a land portion continuous in the tire circumferential direction.

Tire

A pneumatic tire includes a tread portion, carcass, inclined belt, and circumferential belt. The inclined belt is formed by inclined belt layer(s) including cords inclined relative to the tire circumferential direction. A circumferential main groove is provided in the tread portion. The inclined belt includes a high-angle inclined belt layer in which the cords are at an inclination angle of 35&#xb0; to 90&#xb0; relative to the tire circumferential direction. In at least one tread half portion, an edge of the high-angle inclined belt layer in the tire width direction is positioned further outward in the tire width direction than the circumferential main groove disposed furthest outward in the tire width direction. The interval in the tire width direction from the edge to the center of the circumferential main groove is 0.2Wto 0.35W, where Wis the width of the high-angle inclined belt layer in the tire width direction.

Growing community of inventors

Kodaira, Japan

Shintaro Hatanaka