Bridgestone Corporation

Hiroyuki Koseki

Yoshihide Kohno

Yasuo Ohsawa

Shintaro Hatanaka

Norihiko Kaga

Akira Kobayakawa

Shimpei Maeda

Hiroshi Kadowaki

Takuya Yoshimi

This method includes performing adhesion prevention treatment on uncrosslinked rubber powder, which is a material of the rubber product, to prevent mutual adhesion of the uncrosslinked rubber powder, and sequentially and repeatedly forming by supplying raw rubber powder, on which the adhesion prevention treatment has been performed, and irradiating the supplied portion with an electron beam to crosslink the irradiated portion, so that the crosslinked portions are stacked following a shape of the rubber product.

Method of manufacturing rubber product

A method of manufacturing a rubber product by bonding thin pieces on a manufacturing table includes an adhesion prevention treatment step of treating uncrosslinked rubber powder to prevent mutual adhesion, a first raw rubber powder supply step of supplying raw rubber powder, treated for adhesion prevention, onto the surface of the manufacturing table, a first crosslinking step of irradiating with an electron beam to crosslink the irradiated portion, a post-treatment step of aligning the surface of the crosslinked portion with the surface of the manufacturing table, a second raw rubber powder supply step of supplying the raw rubber powder onto the surface of the manufacturing table, including the surface of the crosslinked portion, and a second crosslinking step of irradiating with an electron beam to crosslink the irradiated portion. The post-treatment, second raw rubber powder supply, and second crosslinking steps are sequentially repeated to bond the thin pieces.

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

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

A tire capable of reducing a resistance to a fluid in a groove to improve the wet performances. By forming smaller grooves (or riblets) having a depth set within a range of 0.01 to 0.5 mm at a pitch within a range of 0.01 to 0.5 mm in the walls of a circumferential groove and a transverse groove, more specifically, the resistance to the water flowing in the groove is reduced to improve the drainage efficiency of the groove. By arranging a turbulence generating zone having a number of pointed projections at the groove side faces at the confluence between the circumferential groove and the transverse groove, on the other hand, there is suppressed the separation of the water flow in the vicinity of the confluence. With these constructions, it is possible to improve the wet performances of the tire better than the prior art.

Tire having longitudinally extending smaller grooves formed in the walls of a groove

A pneumatic radial tire having an excellent resistance to uneven wear is provided by optimizing a crown profile of a tread portion, in which at least a radial half section of the crown profile with respect to an equatorial plane of the tire is divided into center and middle and shoulder regions and comprised of a composite arc formed by smoothly connecting at least three arcs having different radii of curvature to each other and each of distances and radii of curvature of these regions satisfies a particular relation.

Pneumatic radial tires with at least three tread radii of curvature

A pneumatic radial tire including a carcass layer having cords embedded therein and arranged perpendicular to an equatorial plane of the tire, and a belt layer including at least one belt ply having a large number of cords embedded therein, the cords including one or more filaments. The cords are disposed radially outside of said carcass layer, arranged substantially in parallel to the equatorial plane of the tire and bent in a wavy or zigzag form. At least those of the cords or filaments located at widthwise outermost locations in the parallel belt ply satisfy the following expression:

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Tokyo, Japan

Yasuo Ohsawa