Toyo Tire Corporation

Koji Arakawa

Noriyuki Tsuji

Yutaka Nakamoto

Tire

A pneumatic tires includes a tread, a pair of sidewalls, and a pair of bead portions that are arranged at intervals wider than a rim width of a corresponding regular rim in a non-rim-assembled state. Each of the pair of the bead portions includes a bead base at an inner diameter side end, a bead heel, and a bead back surface extending from an outer diameter side end of the bead heel, to the outer diameter side. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the width direction. In a rim-assembled state, the bead back surface is in close contact with substantially the entire surface of a radial portion of a rim flange of a regular rim.

Pneumatic tire

A pneumatic tire includes a pair of bead portions that are arranged at intervals wider than a regular rim width in a non-rim-assembled state. The bead portion includes a rim protector, a bead base, a bead heel, and a bead back surface. In the non-rim-assembled state, the bead back surface is formed with a recess that is recessed inward in the tire width direction. The bead back surface has a second curved portion constituting a deepest portion of the recess and a third curved portion extending inward in the tire width direction from the rim protector. When a height of the deepest portion is H2, a height H8 of a virtual intersection of a curve obtained by extending the second curved portion and a curve obtained by extending the third curved portion is larger than 1.5 times H10 and smaller than 3.0 times H10.

A tire distortion detection method includes a first step of forming a portion to be detected on a surface of an inner liner, a second step of detecting the portion to be detected in any two states from a formation of a product tire from a tire component including the inner liner to a change for a load condition on the product tire, and a third step of comparing positions of the portions to be detected in the two states obtained in the second step.

Tire distortion detection method

In a rubber friction test method of measuring a friction coefficient of a rubber test specimen by relatively moving the rubber test specimen and a test road surface in a state in which the rubber test specimen is pressed to the test road surface by applying a load, the method includes a step of measuring a resistance force acting on the rubber test specimen while accelerating or decelerating a speed of the relative movement, and a step of calculating the friction coefficient based on the applied load and the measured resistance force.

Rubber friction test method

A rubber adhesion test method in accordance with the present embodiment has step(s) in which rubber test member is pressed against prescribed road surface for a prescribed contact time and is thereafter pulled away therefrom, the pulling force acting thereon when this is pulled away therefrom being measured, this being performed a plurality of times, with the contact time being varied each time, and step(s) in which a relational expression relating adhesive force and contact time in correspondence to pulling force is derived based on the results of the plurality of measurements.

Rubber adhesion test method and rubber adhesion test system

A device for measuring a tire ground state includes a traveling surface, a tire drive unit, a measuring sheet, a protection sheet which covers the measuring sheet, and a backward and forward tensile force application mechanism. A space conducting the protection sheet to a portion below the traveling surface is formed in at least one of a delay side and an advance side of the measuring sheet in the tire forward traveling direction on the traveling surface. The backward and forward tensile force application mechanism has a roller which is arranged within the space, and is structured such as to pull at least one end of the protection sheet fixed to the roller in the tire forward traveling direction from the below of the traveling surface by rotating the roller.

Growing community of inventors

Itami, Japan

Koji Arakawa