The Yokohama Rubber Co., Ltd.

Yukio Tozawa

Susumu Imamiya

Hiroshi Iizuka

Kazuhiro Shimura

Tomohiko Kogure

Akira Kuramori

Sadakazu Takei

Hiroyuki Kaido

Tadanobu Nagumo

Hisao Kato

Issei Nakakita

Hisao Katoh

Yasuhiro Mizumoto

Masaru Hirai

Masatoshi Kozima

An evaluation method for pneumatic tires and a system thereof, is provided, capable of appropriately evaluating an adverse effect, such as deterioration, of tire temperature by expressing severity of a temperature imposed on a member of tire made of rubber or the like in quantitative and convenient manners. Detection counts are calculated for each detected temperature according to a detection counts calculating unitbased on information of temperatures of pneumatic tires detected by a temperature sensor of a temperature detector. Temperature severity numbers of the pneumatic tires are calculated from a computing equation by a severity calculating unitbased on the detection counts and contribution coefficients of deterioration of tire rubber with temperatures stored in a contribution coefficient storageas parameters. Using the calculated temperature severity number, a determination unitdetermines thermal deterioration of the tire.

Evaluation method for pneumatic tires and system thereof

This invention provides a tire warning device which detects tensile forces of at least one of reinforcing cords of a carcass ply or belt ply of a pneumatic tire and provides a warning on the basis of the tensile forces detected. The tire warning device includes a strain sensor to be attached to the at least one reinforcing cord for sensing a strain of the at least one reinforcing cord, transmitting means for transmitting a signal sensed by the strain sensor, receiving means for receiving a sensed signal from the transmitting means, processing means that calculates the tensile forces of the at least one reinforcing cord on the basis of the sensed signal input from the receiving means and determines whether the warning is provided or not on the basis of the calculated tensile forces, and warning means for providing the warning based on the determination of the processing means.

Tire warning device detecting tensile forces of reinforcing cord and pneumatic tire having the same

Disclosed is a pneumatic tire effectively controlling uneven wear occurring in the vicinity of a main groove even if a groove width of the main groove is narrowed due to change in tread radius during inflation. In the pneumatic tire, with regard to the main groove having its groove width narrowed during inflation among a plurality of main grooves provided on a tread surface, both groove walls are inclined so that the groove width becomes wider toward the groove bottom, and a protrusion dividing the groove space in the tire width direction is provided at the groove bottom.

Pneumatic tire including protrusion dividing groove space of main groove having groove width narrowed during inflation

A system for notifying a driver in a vehicle of a level of danger of an occurrence of tire failure according to the present invention has a danger level assessment device which calculates a danger level assessment value indicating an index showing a probability of the occurrence of the failure from a measured tire inflation pressure and a measured tire running speed, using a characterized danger level assessing function to assess the danger level according to the calculated value. The characterized assessing function is a function of a tire running speed and of a tire inflation pressure, in which a value of the function monotonously increases as the tire running speed increase and as the tire inflation pressure decreases. The danger level assessment value is obtained by adding a cumulative value determined according to usage history of the tire to a value calculated from the danger level assessing function with the measured tire running speed and the measured tire inflation pressure.

System for notifying person of level of danger of occurrence of tire failure

Disclosed is a pneumatic tire effectively controlling uneven wear occurring in the vicinity of a main groove even if a groove width of the main groove is narrowed due to change in tread radius during inflation. In the pneumatic tire, with regard to a zigzag-shaped main groove having the groove width narrowed during inflation among a plurality of main grooves provided on the tread surface, an inclination angle of a groove wall near the shoulder with respect to the tread surface is made relatively large in a bent portion near the shoulder, an inclination angle of a groove wall near the center with respect to the tread surface is made relatively large in a bent portion near the center, and regions where the inclination angles of the opposed groove walls are different from each other are uncontinuously arranged in the tire circumferential direction.

Pneumatic tire having zig-zag circumferential main grooves

A pneumatic tire having improved rolling resistance and increased resistance to separation between coat rubber and steel cords embedded therein. The steel cord is formed from two intertwisted steel filaments containing 0.80-0.92 weight percent of carbon. The rubber coat has 100% elastic modulus of 35-55 kg/cm.sup.2. Each of the cords and the rubber coat has a specified mean cross-sectional area (Sa, Sb). The cords are spaced apart from each other by a specified distance across the junction of adjacent belts.

Pneumatic tire with 1.times.2 steel belt cords

A pneumatic radial tire for passenger cars and heavy duty use is disclosed, which tire has a rubber coated steel cord layer in its belt portion. The cord consists of a pair of steel filaments whose preform ratio 'K' is set in the range of 2.05-K.sub.1 .ltoreq.K.sub.2 &lt;2.50-K.sub.1. Conformance to this preform ratio 'K' provides filaments with periodically alternate contact and non-contact regions longitudinally of the cord.

Pneumatic radial tire with 1x2 steel belt cord

A pneumatic radial tire containing a steel cord/rubber composite reinforcement structure wherein the steel cord comprises a plurality of steel filaments embedded in a rubber layer. The steel cord made up of the filaments is flattened out in the form of a generally cross-sectionally flat, oblong, elongated strip having a specified dimensional parameter such that the filaments in the resulting reinforcement are held out of contact with each other and the overall dimensions of the flat cord are uniform throughout the length thereof

Pneumatic radial tire including steel cords of flat oblong

A pneumatic radial tire arrangement for a vehicle wherein each tire has a belt structure formed of two belt layers respectively made of steel cords and aromatic polyamide fiber cords and which have their edge portions folded back. Each tire is mounted to the vehicle with the folded back portion of the steel cord belt layer located towards the outer side of the vehicle to reduce steering pull during high speed performance of the vehicle.

Pneumatic radial tire arrangement for vehicle

Disclosed is a high hardness rubber composition having a hardness of at least 92, which comprises 100 parts by weight of a rubber, 55 to 95 parts by weight of soft black having an average particle size of 40 to 80 millimicrons, 5 to 30 parts by weight of a thermosetting resin and a small amount of a curing agent, the sum of the amounts of the soft black and thermosetting resin being 60 to 100 parts by weight per 100 parts by weight of the rubber. This high hardness rubber composition is advantageously used as a tire reinforcement for the rim cushion portion or for both the rim cushion portion and bead filler.

Growing community of inventors

Hiratsuka, Japan

Yukio Tozawa