Abstract: A method for producing a wet rubber masterbatch uses a single-screw extruder. The single-screw extruder includes a screw, and an external cylinder in which a slit extended along the length direction of the external cylinder (the screw-shaft direction) is formed in an internal wall surface of the external cylinder, and when the width of the slit is represented by A and the clearance between a crest of the screw and the internal wall surface of the external cylinder is represented by B, the following expression (1) is satisfied: 0<AB(Y)/AB(X)<0.9??(1) wherein AB (Y) is the product of A and B at a downstream side along the screw-shaft direction of the external cylinder, and AB (X) is the product of A and B at an upstream side along the screw-shaft direction of the external cylinder.

Abstract: A sipe is formed in a land portion of a tread surface. The sipe has a 3D sipe portion formed into a three-dimensional shape which changes along a depth direction, and a 2D sipe portion formed into a two-dimensional shape which does not change along the depth direction. The 3D sipe portion extends in the depth direction from the tread surface and terminates at a position which does not reach a sipe bottom. The 2D sipe portion extends in the depth direction from a terminated position of the 3D sipe portion and reaches the sipe bottom. The three-dimensional shape of the 3D sipe portion is formed into a sideways V-shaped form which is bent at one position in the depth direction. Both ends of the sipe are closed within the land portion.

Abstract: A tire mold is provided with a groove-like saw cut in an area of a tire molding surface which comes into contact with a side surface of a tire. The saw cut comprises a pair of circumferential saw cuts arranged to be spaced in a tire diametrical direction, a grid-like saw cut which is expanded between the pair of circumferential saw cuts, and a plurality of frame-like saw cuts which are dotted between the pair of circumferential saw cuts. The frame-like saw cuts fringe a closed area which is wider than a smooth area defined by the grid-like saw cut. The grid-like saw cut surrounds the frame-like saw cuts to prevent the frame-like saw cuts from coming into contact with each other. The frame-like saw cuts are coupled to each other via the grid-like saw cut.

Abstract: An objective of the present invention is to provide a pneumatic tire whereby primarily rolling resistance is minimized and noise is minimized. This pneumatic tire tread rubber (5) comprises: a cap part (50) which is formed of non-conductive rubber and configures a grounding surface; a base part (51) which is disposed on the inner side of the cap part (50) in a tire radial direction (RD); and conductive parts (52) which are disposed in both of a pair of lateral end parts which are at ends of the cap (50) in a tire width direction, traverse the inner part of the cap (50) while avoiding a location which covers the grounding surface, and form shapes which connect the grounding surface with the bottom surface (50b) of the cap part (50) in the tire meridian cross-section. The conductive parts (52) are provided with extended sites (52b) which branch off outward to the tire width direction (WD) from conductive paths (52a) which connect the grounding surface with the bottom surface (50b) of the cap part (50).

Abstract: A tire having a rubber member formed by winding a ribbon rubber in uninterrupted fashion about a rotational axis of the tire. The rubber member has a parallel portion at which the ribbon rubber is parallel to a tire circumferential direction at an end toward an exterior in a tire width direction, and an inclined portion at which the ribbon rubber is inclined with respect to the tire circumferential direction in such fashion as to cause the ribbon rubber to be directed from the parallel portion toward an interior in the tire width direction. The ribbon rubber from which the parallel portion is formed is wound in the tire circumferential direction for a wrap angle of not 360° but N ° (N=210 to 300).

Abstract: The pneumatic tire includes a tread portion having lug grooves, and side portions which are contiguously formed with the tread portion. Projections which differ in at least one of a shape and a size are arranged on a side portion in a plurality of rows in a tire radial direction. Opening positions of small lug grooves on both sides of the tread portion are made to agree with a straight line which passes the projection and extends in the tire radial direction.

Abstract: A bead core coating method for coating an annular bead core with a belt-shaped rubber sheet, including the steps of: winding the rubber sheet around an outer circumferential surface of a rotary drum; sticking a central portion of the rubber sheet to an outer surface of the bead core; and winding both ends in the width direction of the rubber sheet stuck on the outer surface of the bead core while sequentially sticking both ends in the width direction along the outer surface of the bead core from the central portion in the width direction toward each end in the width direction, wherein in the step of sticking, air is blown to a gap generated between the central portion in the width direction of the rubber sheet and the outer circumferential surface of the rotary drum at a place where the rubber sheet is peeled from the rotary drum.

Abstract: A bead core coating method for coating an annular bead core with a belt-shaped rubber sheet including the steps of: winding the rubber sheet extruded on an outer circumferential surface of a rotary drum; sticking a part of the rubber sheet to an outer surface of the bead core which is in rotation; and winding a remaining part of the rubber sheet stuck on the outer surface of the bead core while sequentially sticking the remaining part along the outer surface of the bead core, wherein air is blown to a sheet portion including the end that is not stuck to the outer surface of the bead core in the currently-winding rubber sheet in a first direction toward the end along a sheet surface or a second direction inclined toward an outer surface side of the bead core as compared with the first direction.

Abstract: A pneumatic tire includes a sidewall region extending in a tire radial direction, the sidewall region comprises a plurality of protruding regions that protrude in a tire width direction, a dimension in a tire circumferential direction of at least one of the protruding regions is greater than a dimension of a gap in the tire circumferential direction between an adjacent pair of the protruding regions, and the at least one protruding region is provided with a recess at a side face at a side in the tire circumferential direction.

Abstract: A pneumatic tire including: a circumferential groove that extends in a tire circumferential direction and that partitions a contact patch a protrusion that protrudes from a base of the circumferential groove and that interconnects two groove sidewalls at either side in a groove width direction of the protrusion; and a pair of mutually facing slits that are formed at the groove sidewalls of the circumferential groove. The slits do not extend as far as the contact patch, being closed at interiors of the groove sidewalls; and a length in a groove long direction of the slits is not less than a length in the groove long direction of the protrusion.

Abstract: In a rubber friction test method of measuring a friction coefficient of a rubber test specimen by relatively moving the rubber test specimen and a test road surface in a state in which the rubber test specimen is pressed to the test road surface by applying a load, the method includes a step of measuring a resistance force acting on the rubber test specimen while accelerating or decelerating a speed of the relative movement, and a step of calculating the friction coefficient based on the applied load and the measured resistance force.

Abstract: A pneumatic tire includes a sidewall region extending in a tire radial direction, the sidewall region comprises a plurality of protruding regions that protrude in a tire width direction, a dimension in a tire circumferential direction of at least one of the protruding regions is greater than a dimension of a gap in the tire circumferential direction between an adjacent pair of the protruding regions, and the at least one of the protruding regions is provided with a recess at an outer face in the tire radial direction.

Abstract: A rubber adhesion test method in accordance with the present embodiment has step(s) in which rubber test member is pressed against prescribed road surface for a prescribed contact time and is thereafter pulled away therefrom, the pulling force acting thereon when this is pulled away therefrom being measured, this being performed a plurality of times, with the contact time being varied each time, and step(s) in which a relational expression relating adhesive force and contact time in correspondence to pulling force is derived based on the results of the plurality of measurements.

Abstract: A pneumatic tire including: a circumferential groove partitions a contact patch; and a protrusion that protrudes from a base of the circumferential groove and that interconnects two groove sidewalls at either side in a groove width direction of the protrusion. As seen in plan view, at least one of the two groove sidewalls at either side in the groove width direction of the protrusion has a first region that is adjacent to the protrusion, second regions that are present to either side in the groove long direction of the first region, and a first chamfered region that serves as beveling and that is formed at the first region. Presence of the first chamfered region causes an edge where the contact patch and the groove sidewall of the first region intersect to be more relieved than an edge where the contact patch and the groove sidewall of the second region intersect.

Abstract: An antivibration device capable of securing a thickness dimension of a stopper rubber without changing a gap between a connecting member and a stopper wall portion. A connecting member includes a base surface and a receding surface located to recede beyond the base surface in a direction to go away from a stopper wall portion, the base surface and the receding surface face the stopper wall portion, and a stopper rubber includes an inner fitting portion at which the connecting member is internally fitted. Thus, it is possible to secure a thickness dimension of the stopper rubber without changing a gap between the connecting member and the stopper wall portion.

Abstract: A non-pneumatic tire includes a support structure for supporting a load from a vehicle. The support structure includes an inner annular portion, an outer annular portion concentrically provided on an outer side of the inner annular portion, and a plurality of connecting portions which connect the inner annular portion and the outer annular portion to each other and are provided in a tire circumferential direction independently of one another, the plurality of connecting portions are configured such that elongated plate-like first connecting portions and elongated plate-like second connecting portions are arrayed along the tire circumferential direction, a plate thickness is smaller than a plate width, a plate thickness direction is oriented to the tire circumferential direction, and a plate thickness at a tire radial direction inner end coupled to the inner annular portion is larger than a plate thickness at a tire radial direction center portion.

Abstract: A non-pneumatic tire includes a support structure for supporting a load from a vehicle. The support structure includes an inner annular portion, an outer annular portion concentrically provided on an outer side of the inner annular portion, and a plurality of connecting portions which connect the inner annular portion and the outer annular portion to each other and are provided in a tire circumferential direction independently of one another, the plurality of connecting portions are configured such that elongated plate-like first connecting portions and elongated plate-like second connecting portions are arrayed along the tire circumferential direction, an angle ? and an angle ?, the angles being formed by an inner circumferential surface of the outer annular portion and both side surfaces of each of the connecting portions, both surfaces facing the tire circumferential direction, are 75° or more and 120° or less.

Abstract: A non-pneumatic tire includes a support structure for supporting a load from a vehicle. The support structure includes an inner annular portion, an outer annular portion concentrically provided outside the inner annular portion, and a plurality of connecting portions which connect the inner annular portion and the outer annular portion to each other and are provided in a tire circumferential direction independently of one another, and the plurality of connecting portions are configured such that elongated plate-like first connecting portions and elongated plate-like second connecting portions are arrayed along the tire circumferential direction, the first connecting portions being extended from one side in a tire width direction of the inner annular portion to other side in a tire width direction of the outer annular portion, and the second connecting portions being extended from other side.

Abstract: In a non-pneumatic tire, at least one of a first connecting portions extends in such fashion as to be directed from one side in a tire width direction of an inner annular portion to the other side in a tire width direction of an outer annular portion, at least one of a second connecting portions extends in such fashion as to be directed from the other side in the tire width direction of the inner annular portion to the one side in the tire width direction of the outer annular portion, such that, the at least one second connecting portion appears to intersect the at least one first connecting portion, and that a maximum dimension in a tire radial direction of at least one of the closed spaces is greater than or equal to a maximum dimension in the tire width direction of the at least one closed space.

Abstract: In a pneumatic tire, a first stereoscopic sipe has a fixed sipe width over a sipe depth direction, a second stereoscopic sipe has large width portions having a sipe width wider than a sipe width of the second stereoscopic sipe on a surface of the tread rubber in the inside of the tread rubber, in a vehicle inner side region of the tread rubber disposed on an inner side when the pneumatic tire is mounted on the vehicle, a total of surface lengths of the first stereoscopic sipes is larger than a total of surface lengths of the second stereoscopic sipes, and in a vehicle outer side region of the tread rubber disposed on an outer side when the pneumatic tire is mounted on the vehicle, a total of surface lengths of the second stereoscopic sipes is larger than a total of surface lengths of the first stereoscopic sipes.