Kabushiki Kaisha Bridgestone

Bridgestone Corporation

Akira Kobayakawa

Yasumichi Wakao

Hiroshi Morinaga

Yasuo Ohsawa

Shimpei Maeda

A method, of the present disclosure, of evaluating a tire ground contact property includes mounting a tire on one surface of a flat plate; placing a predetermined load on the tire or placing the tire in a no-load state; irradiating the tire with terahertz waves having a frequency of 0.1 THz to 10 THz from the other surface side of the flat plate or from inside the flat plate, the wavelength of the terahertz waves being greater than the roughness average length in at least a portion of the one surface of the flat plate and/or greater than the roughness average height in at least a portion of the one surface of the flat plate; detecting reflected terahertz waves from the tire; and evaluating the ground contact property of the tire on the basis of the detection result.

Method of evaluating tire ground contact property

An intra-tire power generating apparatus capable of producing high power is provided. The apparatus includes rotary magnets and rotary weights, which rotate in response to variations in centrifugal force and circumferential acceleration working on the tire of a running vehicle, and a coil unit, which is located between two rotary magnets facing each other and generates voltages through electromagnetic induction from the rotary magnets. In the apparatus, the rotary magnets and the rotary weights have an identical center line of rotation. The rotary weights are so formed as to have their center of gravity dislocated from the center line of rotation. The rotary magnets are each provided, in the plane orthogonal to the center line of rotation, with an even number of regions adjoining in the circumferential direction around the center line of rotation, the adjoining regions having different magnetic poles from each other. The two rotary magnets facing each other are so configured as to rotate while maintaining the opposition of their respective regions having mutually opposite magnetic poles. And the coil unit has coil windings, each of which is of a tubular shape surrounding a space through which the magnetic flux generated between the mutually opposite magnetic poles of the two rotating rotary magnets passes.

Intra-tire power generating apparatus

This invention provides a tire () equipped with a sensor (), attached to a rubber member () in the surface of the tire (), for detecting deformation of the tire (). The sensor () is adhered to the rubber member () with the aid of an elastic adhesive formed of a room-temperature moisture cure adhesive agent composed mainly of an acryl modified silicone resin or the like. The adhesive between the sensor () and the rubber member () is cured to form an elastic adhesive layer (). According to the above constitution, the deformation of the rubber member () in the tire surface can be transmitted to the sensor () with high accuracy, and, at the same time, the durability of the sensor () can be improved.

Tire equipped with a sensor and a method of measuring strain amount of the tire

The dynamic state amount of a tire when a load is applied to the tire while running can be estimated accurately and stably by installing tire deformation amount measuring meansA andB at axisymmetrical positions which are equally distant in the axial direction from the center in the axial direction of the tire on the cross-section in the radial direction of the tire on the inner side of the belt portion of a tire tread in the radial direction, such as at the inner surface of the tread, between an inner liner and a ply, between plies or between a ply and a belt to measure the waveforms of deformation of the tire, detecting the contact time which is the time difference between contact edges from the waveforms of deformation, calculating contact length indices kand kfrom the contact time and the wheel speed detected by a wheel speed sensor, calculating the average value k of the above indices kand k, and obtaining a load applied to the tire by using the calculated average value k of the indices of contact length and a mapM showing the relationship between the average value of the indices of contact length and load pre-stored in memory means

Estimation method and apparatus of tire dynamic state amount and tire with sensors

A method for estimating accurately and stably the change of forces exerted on the tire or change of contact condition with the ground of the tire and an apparatus for putting it in operation. Prepare a tire with sensors disposed therein such that the first and the second deformation amount measurement meansA andB positioned on the vehicle body side and on outside, respectively, each of which comprises a lengthy detection portionmade of a conductive rubber member buried in the tire treadand placed in a circumferential direction of the tire and comprises of detection electrodesat both ends of the detection portion; and upon computing contact length with the ground of the tire vehicle body side and on the outside, from detected resistance value of the detection portionincluded in the means ofA and the wheel speed and from the resistance value ofincluded in the means ofA and the wheel speed and from the resistance value ofincluded in the meansB and the wheel speed, respectively, the load exerted on the tire and the lateral force exerted on the tire can be estimated form the average value and the difference value, respectively of the contact length on the vehicle body side and on the outside, respectively.

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Tokyo, Japan

Akira Kobayakawa