Bridgestone Corporation

Wsl Institute for Snow and Avalanche Research Slf

Tatsuya Nakai

Yasuo Shibata

Tatsuhiko Hatano

Masaki Wada

Masafumi Koide

Eisuke Seta

Ietomo Matsunaga

Tadashi Wakiyama

Shoji Hayashi

Martin Schneebeli

Denes Szabo

Henning Loewe

Martin Heggli

Felix Hempel

Matthias Jaggi

Jorg Graupeter

A vulcanization mold including blades having a distal end side and pullout is performed smoothly without causing any failure and a pneumatic tire. A vulcanization mold in which a blade has a proximal end, a blade distal end side expanded in a thicknesswise direction on the distal end side, and a blade connection portion that connects the proximal end portion and the blade distal end side is a vulcanization mold in which a sweep area is the difference where a cross sectional area of the blade connection is subtracted from an area blade distal end side to a mold surface with a width equal to a maximum width of a thickness of the blade distal end side in a cross sectional shape perpendicular to a tire widthwise direction of the blade is smaller in circumferential end side regions than in a circumferential central side region of the sector mold.

Vulcanization mold and pneumatic tire manufactured with the mold

A vulcanization mold in which a blade has a blade proximal end portion, a blade distal end side thick portion expanded in a thicknesswise direction on the distal end side, and a blade connection portion that connects the portions to each other, is a vulcanization mold wherein a sweep area that is the difference where a cross sectional area of the blade connection portion is subtracted from an area from the blade distal end side thick portion to a mold surface with a width equal to a maximum width of a thickness of the blade distal end side thick portion in a cross sectional shape perpendicular to a tire widthwise direction of the blade is smaller at the blades in circumferential end portion side regions than at the blades in a circumferential central portion side region of the sector mold. Further, a pneumatic tire is manufactured using the vulcanization mold.

A vulcanization mold is a mold including blades having a distal end side thick portion and pullout is performed smoothly by the mold without causing any failure, and a pneumatic tire. A vulcanization mold in which a blade or has a blade proximal end portion, a blade distal end side thick portion expanded in a thicknesswise direction on the distal end side, and a blade connection portion that connects the blade proximal end portion and the blade distal end side thick portion to each other is a vulcanization mold in which a blade density that is a number of blades implanted on a sector mold per unit length in a circumferential direction is lower at the blades in circumferential end portion side regions than at the blades in a circumferential central portion side region of the sector mold. Further, a pneumatic tire is manufactured using the vulcanization mold.

An object is to improve noise performance of a tire while enhancing movement performance thereof. At least one of the land portions () includes an outer wall surface () positioned on a vehicle outer side, an inner wall surface () positioned on a vehicle inner side, a tread surface () on an outer side in a tire radial direction, an outer edge () of the tread surface () in contact with the outer wall surface (), and an inner edge () of the tread surface () in contact with the inner wall surface (). The tread surface () is formed in a convex shape which is smoothly curved between the outer edge () and the inner edge () and which has a top portion () most protruded outward in the tire radial direction, in a cross section of the land portion () in a tire width direction. A relationship of Do &#x3c;Di is satisfied when a distance between the top portion () and the outer edge () in the tire radial direction is denoted as Do, and a distance between the top portion () and the inner edge() in the tire radial direction is denoted as Di. The top portion () is positioned closer to the inner edge () side from a center (P) of the land portion () in the tire width direction.

Tire

Disclosed is a method for predicting tire performance in which a tire model, which comprises a tread pattern capable of imparting deformation by means of ground contact and/or transfer, and a snow model, in which a snow-covered road surface that comes into contact with the tire model is represented, are used to predict tire performance on the snow-covered road surface on the basis of physical quantities that occur in at least either of the tire model and the snow model. The snow model is modeled as an elasto-plastic body or an elastic body, the nonlinearity of the volume compression property of snow is represented by the relationship between the density or volume strain of the snow and the pressure of the snow, and the shear property of the snow is represented by the relationship between the yield stress of the snow and the pressure of the snow.

Tire performance prediction method and method of designing tire

Growing community of inventors

Tokyo, Japan

Tatsuya Nakai