Abstract: A vent plug is mounted in a vent hole open in a molding face of a tire cure mold. The vent plug has a cylindrical housing having a vent path in itself, a stem that is inserted into the housing and serves as a valve element for opening and closing the vent path, and a coil-shaped spring that biases the stem toward a cavity so as to open the vent path. The vent path includes an outer inlet portion open in an annular shape between a valve seat provided to the housing and a head portion of the stem that comes in contact with the valve seat, and an inner inlet portion open in an annular shape on an inner side of the outer inlet portion.

Abstract: A vent plug is mounted in a vent hole open in a molding face of a tire cure mold. The vent plug has a cylindrical housing having a vent path in itself, a stem that is inserted into the housing and serves as a valve element for opening and closing the vent path, and a coil-shaped spring that biases the stem toward a cavity so as to open the vent path. The stem includes a columnar trunk portion and a head portion that comes in contact with a valve seat at an opening portion of the housing to thereby close the vent path. The stem turns as the stem moves along an axial direction.

Abstract: A tread portion of a pneumatic tire is divided into a center region at a center portion in a tire width direction and shoulder regions disposed on both sides of the center region. Each of the center region includes ribs which are formed by a plurality of main grooves extending in a tire circumferential direction. The shoulder region includes: a plurality of inclined grooves which are inclined toward the outside in a tire width direction and toward a direction opposite to a tire rotational direction at the time of advancing a vehicle; and a shoulder block surrounded by the inclined grooves.

Abstract: A pneumatic tire includes a center land portion between two center main grooves, a mediate land portion between a center main groove and a shoulder main groove, and a shoulder land portion between the shoulder main groove and a grounding end (E). Each of the center main grooves extends in a zigzag manner by alternately arranging long first groove portions and short second groove portions that are inclined with respect to a circumferential direction of the tire, respectively. A bulging portion in a tire width direction is formed in the center land portion. Each of the first groove portions of the center main groove is inclined such that a portion to be grounded later heads toward the grounding end (E) side. Each first lateral groove traverses the mediate land portion and the shoulder land portion and forms a notch in the bulging portion in the center land portion.

Abstract: To obtain a uniform ground contact pressure distribution in a pneumatic tire including a zigzag-shaped sipe. In a pneumatic tire according to an embodiment, a land portion formed in a tread portion is provided with a zigzag-shaped sipe extending in a tire circumferential direction. The zigzag-shaped sipe is formed in a zigzag shape by a plurality of lateral sipe portions arranged at intervals in the tire circumferential direction and a plurality of longitudinal sipe portions alternately connecting the end portions thereof. Each longitudinal sipe portion includes an extension portion in which one end portion (for example, an end portion on a rear side in a rotation direction) of both end portions in the tire circumferential direction extends to the one side beyond a connection portion with the lateral sipe portion.

Abstract: In a pneumatic tire in which protrusions (90 and 95) are provided in main grooves (10 and 15) extending in a circumferential direction of the tire, upper surfaces (91 and 96) of the protrusions (90 and 95) are inclined so as to be higher on a tire grounding end side and lower on a tire equator side, surfaces (92 and 97) on stepped sides of the protrusions (90 and 95) extend in the tire width direction, and surfaces (93 and 98) on kick-out sides of the protrusions (90 and 95) are inclined such that a portion closer to the tire equator side approaches to the surfaces (92 and 97) on the stepped sides.

Abstract: To obtain a uniform ground contact pressure distribution in a pneumatic tire in which an edge portion of a land portion is provided with a notch portion. In a pneumatic tire according to an embodiment, an edge portion of a land portion formed in a tread portion is provided with a notch portion having a triangular shape in the plan view. A wavy sipe is provided to extend from an apex corner portion of the notch portion into the land portion and a straight sipe is provided adjacent to the wavy sipe with a gap interposed therebetween to extend into the land portion and to open to the edge portion of the land portion.

Abstract: To provide a pneumatic tire capable of improving rut running performance. In a pneumatic tire according to an embodiment, a shoulder block provided in a shoulder region of a tread portion is provided with a plurality of sipes which are formed at intervals in a tire circumferential direction to extend in a tire width direction. In the plurality of sipes, a dimple is provided on an outside in the tire width direction in relation to each tire ground contact end in a communication state. The dimple includes a portion formed with a wide width from a connection portion with the sipe toward the outside in the tire width direction and maximum width portions of the plurality of dimples are disposed to be offset in the tire width direction.

Abstract: A pneumatic tire includes land portions defined by grooves, and sipes that are formed in the land portions and intersect the grooves. The sipes form acute angle portions and obtuse angle portions with the grooves. Notches are formed in the obtuse angle portions.

Abstract: A pneumatic tire includes blocks (36 and 41) formed by main grooves (10 and 15) extending in a circumferential direction of the tire and lateral grooves (20 and 25) extending in a tire width direction, and notches (50, 60, and 70) in stepped side end portions of the blocks (36 and 41). The lateral grooves (20 and 25) extend obliquely such that a tire grounding end (E) side is grounded later. Portions adjacent to the notches (50, 60, and 70) on the tire grounding end (E) side of the notches (50, 60, and 70) are protrusions (51, 61, and 71) protruding while forming an acute angle toward a tire equator (C) side.

Abstract: A pneumatic tire includes a block (41) formed by being partitioned by a main groove (15) and lateral grooves (20 and 25), and a block traversing sipe (45) which is a sipe longitudinally traversing the block (41), in which the block traversing sipe (45) has a zigzag shape that is constituted by a plurality of longitudinal sipe portions (42) extending in a circumferential direction of the tire, and a lateral sipe portion (43) extending in a tire width direction and connecting end portions of two longitudinal sipe portions (42), and a longitudinal sipe portion (42) closer to a kick-out side of the block (41) has a narrower width.

Abstract: To prevent an interrupted portion in a sipe in a case in which a pneumatic tire with a sipe continuous in a tire circumferential direction has a pitch variation. A pneumatic tire according to an embodiment includes a tread portion 10 in which a plurality of pitch patterns having different pitch lengths are arranged in a tire circumferential direction. A rib extending in the tire circumferential direction of the tread portion is provided with a sipe continuous in the tire circumferential direction. The sipe is formed by repeating a sipe component in the tire circumferential direction and each pitch pattern includes the plurality of sipe components. A position in the sipe component at each boundary between the pitch patterns is set to the same position and a length of the sipe component in the tire circumferential direction is set according to the pitch lengths of the pitch pattern.

Abstract: To provide a pneumatic tire capable of improving rut performance. A pneumatic tire according to an embodiment is a tire having a specified rotation direction. A shoulder region of a tread portion is provided with a shoulder block and a raised portion is provided in an outer extension portion of the shoulder block in a tire width direction in relation to a tire ground contact end. The raised portion includes a corner portion which protrudes from an edge portion of the shoulder block on a front side in the rotation direction toward the front side in the rotation direction.

Abstract: In a pneumatic tire, an annular sipe (80) is provided in a land portion (36), and the annular sipe (80) is constituted by a plurality of independent small sipes (81) extending in a circumferential direction of the annular sipe (80).

Abstract: A pneumatic tire includes a center land portion (30), a mediate land portion (35), a shoulder land portion (40), and shallow grooves (33, 38, and 43) on a surface of each of the land portions (30, 35, and 40), in which the shallow grooves (33 and 43) in the center land portion (30) and the shoulder land portion (40) have many components in a circumferential direction of the tire, and the shallow grooves (38) in the mediate land portion (35) have more components in a tire width direction than the shallow grooves (33 and 43) in the center land portion (30) and the shoulder land portion (40).