Bridgestone Corporation

Kabushiki Kaisha Bridgestone

Makoto Ishiyama

Masafumi Koide

Jun Matsuzaki

Takayuki Fukunaga

Shinsaku Katayama

Hiroyuki Matsumoto

Daisuke Hotta

Takumi Kakara

Takashi Kawai

Masahumi Koide

An aircraft tire management system includes a management device capable of communicating with a tire manufacturer, an MRO-providing company, and an airline through a network, and an acquisition device configured to acquire tire individual information on aircraft tires and wheel individual information on wheels. The acquisition device sends the tire individual information acquired in the tire manufacturer to the management device, sends the tire individual information and the wheel individual information on each aircraft tire fitted on the corresponding wheel acquired in the MRO-providing company to the management device, and sends the wheel individual information acquired in the airline to the management device. The management device links the tire individual information with the wheel individual information, and outputs tire management information including at least tire identification information, location information, and date and time information.

Aircraft tire management system, aircraft tire management device, and aircraft tire program

Driving stability and durability is efficiently improved. Since a protecting layerembedded with reinforcing cordsis disposed between a treadand a belt reinforcing layer, both of the protecting layerand the belt reinforcing layerdecentrally bear a large bending force generated when a pneumatic tireruns on a sharp projection or a difference in level. As a result, even if reinforcing elementsin the belt reinforcing layerare extended by large tension due to fill internal pressure, increase of strain generated in the reinforcing elementscan be effectively suppressed.

Pneumatic tire

A pneumatic tire for motorcycles includes a carcass extending toroidally between a pair of bead portions, at least one ply of a belt layer installed outside thereof in the tire radial direction, and a tread portion radially outside the belt layer. In the tread portion, the 50% region of the developed width of the tread whose center is on the tire equatorial plane is a 'tread center portion', the 25% regions of the developed width of the tread region on either side of the tread center portion are a 'tread side portion', and each tread side portion is divided into three equal parts in the tire width direction defined from the tread end in order as regions A, B and C. The average modulus of elasticity in region B at 100% elongation at 40&#xb0; C. is larger than the average modulus of elasticity in region A and in region C at 100% elongation at 40&#xb0; C.

Pneumatic tire for motorcycle

The present invention aims to provide a pneumatic tire for a motorcycle capable of improving turning performance on a wet road surface as compared to that of conventional tires. The pneumatic tire for a motorcycle comprises a treadconsisting of a tread central portion having a width of 60% of a tread developed width and tread side portions located outside of the tread central portion in the width direction of the tire and a plurality of wide inclined groovesand narrow inclined groovesinclined at an angle of less thandegrees with respect to the circumferential direction of the tire formed in the tread side portion such that the grooves continuously extend over a region of 50% or more of a width of the tread side portion. A groove width of the narrow inclined groovesis set within a range between 0.3 mm and 2.5 mm. A total area of the wide inclined groovesis set to not more than 20% of an area of the tread side portion. Such configuration can satisfy both of drainage performance and block stiffness of the tread contact portion in turning at a high level to obtain a higher grip force in turning on a wet road surface than that of conventional tires.

The pneumatic tire for two-wheeled vehicles including a plurality of tread rubbers constituting a tread wherein a region occupying 15 to 35% in the center of a stretched tread width, which is obtained by stretching the tread with respect to a tire equatorial plane as the center, is defined as a tread central section; the remaining regions at both ends are defined as tread side sections; regions in the respective tread side sections each occupying 4 to 13% from the corresponding tread end toward the center of the stretched tread width are defined as side-section shoulder-end regions; and the remaining regions of the respective tread side sections are defined as side-section near-center regions, a modulus of the tread rubbers for the side-section shoulder-end regions at 100% elongation is smaller than a modulus of the tread rubbers for the side-section near-center regions at 100% elongation, at least at a tread surface.

Pneumatic tire for two-wheeled vehicle

A pneumatic tirehaving a toroidal carcassand a beltconsisting of belt layersarranged in the outer circumferential side of a crown portionof the carcass. Between the adjacent belt layers, the cordsare crossed with each other with respect to an equatorial plane E of the tire to form cross belt layers. The widest belt layeris a folded belt layer having a body portionand a folded portion. A cordconstituting the folded belt layeris an organic fiber cord. A narrow belt reinforcing layerof rubberized cordsis arranged at least immediately below the width terminal endof the body portionof the folded belt layerwhich terminal endabuts on the folded portion

Pneumatic tire with narrow belt reinforcing layer immediately below with terminal end of folded belt layer

A pneumatic tire for a motorcycle in which partial abrasion is suppressed by making the slip component of a tread lubber in the circumferential direction of tire as uniform as possible in the ground contacting plane. A cushion rubber layerhaving elastic modulus lower than that of the tread rubberis arranged on a spiral belt layer, and an inclination belt layerincluding a cord inclining at an angle of 45 to 90 degrees to the circumferential direction of the tire is arranged on the cushion rubber layer. Consequently, shear deformation of the cushion rubber layerduring traveling can be transmitted to the tread rubberafter being smoothed by the inclination belt layer. As compared with a case not provided with the cushion rubber layerand the inclination belt layer, shear deformation of the tread rubber layercan be reduced relatively because shear deformation occurs in the cushion rubber layerin place of the tread rubber; and since the slip component of the tread rubberin the circumferential direction of the tire becomes substantially uniform in the ground contacting plane, partial abrasion can be suppressed.

The ground contact pressure on land portionsis uniformed so that drivability is improved and uneven wear is suppressed to improve wear resistance. The parts of the carcass layerand belt layeroverlapping with the main groovesare convexly curved toward the outside in the radial direction due to the internal pressure. The reinforcing layeris arranged at the position spaced from the neutral axis of deformation in the compressed side in a certain distance, i.e. radially inside of the radially outermost carcass ply, and the steel cordswhich extend in the direction including the tire width direction and its approximate direction and which act as supports for resisting against the compression force are embedded in the reinforcing layer. As a result, the above-mentioned curved deformation can be effectively suppressed.

Auxiliary grooves are formed in land portions so that the wet performance is improved by the increase in the edge factors of the auxiliary grooves and by the water absorbing actions of the auxiliary grooves . Since the auxiliary grooves are arranged on the shorter diagonal lines of the land portions , the land portions are divided into two triangles approximating equilateral triangles so that the reduction, as caused by providing the auxiliary grooves , of the rigidity of the land portions can be suppressed to the minimum. As a result, the deformation of the land portions is suppressed to maintain the dry performance.

Pneumatic tire including auxiliary grooves

A pneumatic tire in which a block formed in a tread surface has, in a ground contacting surface thereof, a closed sipe which is formed so as to not open onto a groove. The sipe has a first opening formed in the ground-contacting surface of the block, a second opening formed at side surfaces of the block, and a hole which communicates the first opening and the second opening. In accordance with this structure, water taken-in into the sipe from the first opening at the ground-contacting surface of the block is discharged to the second opening contacting at the side surface facing to the groove. As a result, water drainability of the sipe is improved without lowering rigidity of the block. Thus, a ground contacting performance of the block improves. The pneumatic tire therefore has improved performance on wet roads and improved performance on snowy and icy roads without the rigidity of blocks decreasing.

Pneumatic tire including water drainage passage

A pneumatic tire. A central circumferential main groove is disposed to extend along a tire circumferential direction, along a ground contact center line of tread of the pneumatic tire. Inboard side circumferential main grooves and inboard side lateral main grooves, which are continuous with the central circumferential main groove, are provided at an inboard side of the ground contact center line. Outboard side lateral main grooves, which are continuous with the central circumferential main groove, and outboard side slanted longitudinal main grooves, which are continuous with the outboard side lateral main grooves, are disposed at an outboard side of the ground contact center line. Thus, irregular wear of land portions is continuously suppressed and controlling stability is improved. Moreover, water at the ground contact center line, which water is difficult to drain, can be efficiently drained from the ground contact area due to less water resistance. In short, the present invention enables a pneumatic tire with improved tire wear resistance, high wet condition drainage ability and improved controlling stability.

Pneumatic tire having tread including inboard side area and outboard side area

In a pneumatic tire of the present invention, a pair of circumferential main grooves with a tire equatorial plane interposed therebetween, and another pair of circumferential main grooves at a tire axial direction outer side and inner side of the former pair of circumferential main grooves, are provided in a central area of a tread. A groove width center line of the circumferential main grooves at the tire axial direction outermost side and innermost side is disposed at a position 30% to 40% of a ground contact half width distanced from the tire equatorial plane. Further, outboard side slanted longitudinal main grooves, and slanted lateral main grooves having ends which open into at least one of the circumferential main grooves and other ends which open into contact ground end in the vehicle width direction, are disposed on the tread. Accordingly, irregular wear of land portions can be suppressed, controlling stability can be improved, and water at the ground contact surface can be efficiently drained from the ground contact surface with less drag from the water, even if the tread width of the tire is wide. In short, a pneumatic tire is provided in which high wet condition drainage performance, controlling stability and tire wear resistance can be altogether improved.

Pneumatic tire including three circumferential grooves

A method of designing a tire which takes into consideration actual conditions in the presence of a fluid, such as drainage performance, on-snow performance, noise performance, and the like. A tire model and a fluid model including the shape, structure, and the like are constructed, and a road surface condition is inputted (steps to ). Boundary conditions during tire rolling or tire nonrolling are set (step ), deformation calculation and fluid calculation of the tire model are performed (steps to ), and a boundary surface between the tire model and the fluid model is recognized to update the boundary conditions (steps and ). The result of calculation is outputted as the result of estimation, and based on this result of estimation, main travel paths of the fluid, i.e., streamlines, are adopted (step ), grooves are formed along the determined streamlines so that a tire model with patterns is constructed (steps and ), and the draft design having satisfactory performance is adopted (steps to ).

METHOD OF DESIGNING A TIRE, METHOD OF DESIGNING A VULCANIZING MOLD FOR A TIRE, METHOD OF MAKING A VULCANIZING MOLD FOR A TIRE, METHOD OF MANUFACTURING A PNEUMATIC TIRE, AND RECORDING MEDIUM WITH TIRE DESIGNING PROGRAM RECORDED THEREON

When a single performance or a plurality of antinomical performances are to be achieved, the best mode of a tire is designed under a given constraint condition. Each of blocks included in two pitch groups designated in a pitch array is modeled ( ), an objective function representing a tire performance evaluation physical amount, a constraint condition for restricting a tire shape, and a design variable which is an angle of a wall surface determining each of block shapes are determined ( ). Next, the design variable is varied continuously by r to determine a modified model ( to ). A value of the objective function of the modified model and a value of the constraint condition are calculated, and a sensitivity of the objective function and a sensitivity of the constraint condition are determined ( ). A variation amount of the design variable which minimizes a difference between block rigidities is estimated, a modified shape model is determined, the objective function is calculated, and by using a value of the design variable, a block shape of each of the pitch groups in the pitch array forming the tire is determined ( to ).

Pneumatic tire designing method

When a single performance or a plurality of antinomical performances are to be obtained, the best mode of a tire is designed under a given condition. A basic shape model using one block as a reference shape is obtained (,). An object function representing a tire performance evaluation physical amount, a constraint condition for restricting the tire shape, and a design variable which is an angle of a wall surface which determines the block shape are determined (,). Next, the design variable is varied continuously by &Dgr;r,to determine a modified shape model (,to,). A value of the object function of the modified shape model and a value of the constraint condition are calculated, and a sensitivity of the object function and a sensitivity of the constraint condition are determined (,). A variation amount of the design variable which minimizes a standard deviation of block rigidities is estimated, a modified shape model is determined, an object function value is calculated, and a block shape forming the tire is determined by using the value of the design variable (,to,).

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Kodaira, Japan

Makoto Ishiyama