Abstract: A pneumatic tire includes, on a tread surface, at least one water absorption hole that includes a narrow-diameter portion on the tread surface side and a wide-diameter portion, on the hole bottom side, with a larger diameter than the narrow-diameter portion. In a reference state, the water absorption hole extends at an inclination relative to the normal direction of the tread surface, an average cross-sectional area of the narrow-diameter portion in a cross-section perpendicular to the extending direction of the narrow-diameter portion over the extension length thereof is 0.2 to 20 mm2, and the diameter of the wide-diameter portion is 1.4 or more times that of the narrow-diameter portion in the cross-section perpendicular to the extending direction of the narrow-diameter portion. In a transparent plan view from the tread surface side in the reference state, the opening of the narrow-diameter portion to the tread surface overlaps the wide-diameter portion.

Abstract: 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.

Abstract: A pneumatic tire includes a tread portion and at least one sipe on a tread surface of the tread portion. The sipe includes a first sipe portion on the tread surface side, a second sipe portion on a sipe bottom side, and a wide-diameter portion, between the first sipe portion and the second sipe portion, having a sipe width larger than a sipe width of the first sipe portion and a sipe width of the second sipe portion. At least a bottom portion of the wide-diameter portion is included in an intermediate tread rubber layer located at an intermediate position in a tire radial direction between a tread rubber layer forming the tread surface and a tread rubber layer on an innermost side of the tread portion in the tire radial direction.

Abstract: 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.

Abstract: A pneumatic tire, wherein, in a state of being mounted on a rim, defining the rim diameter as D, the length from the rim position representing the rim diameter D to the maximum tire radial height as SH, the rim flange height as G, the rim flange radius as R2, and the bead filler height Hbf as the tire radial height with respect to the rim position representing the rim diameter D, the bead filler height Hbf is less than or equal to a value obtained by the following formula: {SH?(G?R2)}/4+(G?R2). The cord is provided in at least one part from a bead portion to a sidewall portion 3 at an angle of 0 to 10° to the circumferential direction.

Abstract: In a pneumatic tire (1) that achieves both ride comfort and steering stability at a high level, a bead core (5) has a ratio of the maximum width of the core to the height of the core of 0.8 or less in a cross-section in the tire width direction. A cord (9) is provided in at least one part from a bead portion (2) to a sidewall portion (3) at an angle of 0 to 10° with respect to the circumferential direction. The cord (9) has an inflection point in a stress-strain curve, with a low elastic modulus in a low-strain region at or below the inflection point, and a high elastic modulus in a high-strain region above the inflection point.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: The reduction of noise in the rotation of the tire and the improvement of resistance to hydroplaning are established and also the resistance to uneven wear is improved, in which four circumferential main grooves 2-5 are formed asymmetrically, and a sum of groove volume in a circumferential direction in lateral grooves formed in a shoulder land part row 7 as a portion of an axially inner side per unit width is made smaller than a sum of groove volume in the circumferential direction in lateral grooves 11 formed in a shoulder land part row 9 as a portion of an axially outer side and a land part row 6 in a central region is rendered into a rib, and slant grooves 13 extending at an average inclination angle of not less than 45° with respect to a widthwise direction of the tread are arranged in a second inner land part row 8 located at a side of an equatorial line adjacent to the shoulder land part row 7 at the axially inner side and these slant grooves 13 are opened to the circumferential main groove located adja

Abstract: This invention relates to a tire suitable in a passenger car, particularly a tire being high in the resistance to hydroplaning on a wet road surface and low in the tire noise and having an asymmetric tread pattern.

Abstract: A tire capable of reducing a resistance to a fluid in a groove to improve the wet performances. By forming smaller grooves (or riblets 20) 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.

Abstract: A method of simulating tire performance of the present invention includes the steps of: (a) preparing a tire model by dividing a patterned tire, which includes a pattern formed from a plurality of land portions, into plural parts, and expressing each part by a part model formed from a large number of divisional elements, and combining a plurality of the part models; (b) expressing a suspension as a suspension model formed from a large number of divisional elements; and (c) analyzing performance of the patterned tire in a state in which the patterned tire is in use, by using, as one numerical computational model, a first numerical computational model including the tire model and a second numerical computational model including the suspension model. In accordance with the present invention, when simulating tire performance, creation of a model and change between plural patterns can be easily performed.

Abstract: A tire capable of reducing a resistance to a fluid in a groove to improve the wet performances. By forming smaller grooves (or riblets 20) 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.

Abstract: 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.

Abstract: 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:d.times.a/.lambda..sup.2 .ltoreq.0.005and the cords or filaments in the parallel belt ply satisfy the following expression:a/.lambda..ltoreq.0.1wherein d is a filament diameter of the cords or filaments; .lambda. is a wavelength of the form; and a is one half of the amplitude of the form.