The surface state of the treads of tires cured in a vulcanization mold manufactured by 3D printing represents an optimal compromise between cost, appearance, and grip performance of the tire. The texture is formed by an arrangement of contiguous elements of pyramidal shape, each element of pyramidal shape having a base of parallelogram type positioned on the tread surface, and an apex situated at a normal distance H from the base in the range 0.15 mm to 0.5 mm.

A tire vulcanization mold includes a side molding surface, a mark forming stencil plate for forming a convex mark at an outer surface of a side portion, an attachment recess provided in the side molding surface, and a screw fixing the stencil plate to the attachment recess. The stencil plate is formed larger than the attachment recess so as to cover the attachment recess, and a peripheral portion of the stencil plate is in contact with an opening peripheral portion of the attachment recess.

A method is for producing a profile segment of a segmented casting-vulcanizing mold for vehicle tires, the molding area of which molds a segment of the tread profile of a tire to be vulcanized, including the steps: creating a rigid model segment having a casing-like tread surface; milling the profile positive of the tread into the casing-like tread surface of the model segment to obtain the master model; creating a flexible impression from the master model; creating a rigid plaster cast from the impression to form a casting core segment; casting all of the annular, placed-together casting core segments with an aluminium-magnesium alloy to obtain a vulcanizing mold, subsequently divided into profile segments. A plasma coating is applied to the tread of the model segment, into which the profile positive of the tread is subsequently milled to obtain the master model. Plasma coating gives the master model a defined roughness.

A vulcanizing bladder 3 comprises a first bladder 11 configured to contact with an inner circumferential surface of an unvulcanized tire (T) and a second bladder 12 arranged inside the first bladder 11. A first fluid G1 is to be supplied between the first bladder 11 and the second bladder 12, and a second fluid G2 is to be supplied to an inside of the second bladder 12. At least one of an inner circumferential surface 11s of the first bladder 11 and an outer circumferential surface 12s of the second bladder 12 is provided with a guide groove 31 extending in a tire axial direction through which the first fluid G1 can pass.

A tire mold capable of imparting appropriate amounts of heat according to regions of an uncured tire is provided. The tire mold includes a base mold and a pattern mold which is fitted to the base mold and has a surface part for molding a tread pattern on the tire. A heat adjusting agent for adjusting amounts of heat to be transmitted to the tire via the surface part of the pattern mold is placed in a hollow cavity formed between the base mold and the pattern mold or inside the base mold.

A sipe is provided to a land portion provided to a tread of a pneumatic tire. The sipe is formed of a wide portion having a groove width W1 and a narrow portion having a groove width W2 narrower than the groove width W1. The wide portion extends in a sipe depth direction D at both ends in a sipe length direction L and extends in the sipe length direction L at an upper end in the sipe depth direction D. The narrow portion is surrounded by the wide portion on three sides including both sides in the sipe length direction L and an opening side in the sipe depth direction D and extends to a sipe bottom. Consequently, chipping of rubber is suppressed by reducing pulling resistance of a sipe plate at the time of die releasing of a tire while suppressing breakage of the sipe plate.

A tire vulcanizing mold is disclosed capable of accurately providing a clearance, from which air existing between a green tire and a side mold is released, on a side shaping surface and thereby preventing shaping defect. The tire vulcanizing mold includes an upper and lower pair of side molds having side shaping surfaces, each of which shapes a sidewall of a tire. Each of the side molds includes a side mold main body, plural pieces, and a clearance provided between the side mold main body and each of the pieces. The side mold main body includes plural recesses, each of which is closed in a tire circumferential direction and a tire radial direction and is opened to a side shaping surface, at spaced intervals in the tire circumferential direction. Each of the pieces is fitted into the recess and forms the side shaping surface with the side mold main body.

A tire vulcanization mold 10 of an embodiment includes a side mold 14 having a side molding surface 20 for molding a side wall portion. The side mold 14 includes: a side mold body 24 having a plurality of recesses 30 provided at intervals in a tire circumferential direction; a plurality of side pieces 26 fitted into the recesses 30 and forming an annular side molding surface 20 together with the side mold body 24; and a plurality of vent gaps 28 provided between side surfaces 26A on both sides in the tire circumferential direction of the side pieces 26 and wall surfaces 30A of the recesses 30. An inner end 26E in a tire radial direction of the side piece 26 is positioned inwardly in the tire radial direction from an inner end 20E in the tire radial direction of the side molding surface 20.

A tire vulcanization mold 10 of an embodiment includes a side mold 14 having a side molding surface 20 for molding a side wall portion. The side mold 14 includes: a side mold body 24 having recesses 30 provided in the side molding surface 20; a side piece 26 fitted into the recess 30 to form a vent gap 28 with a wall surface of the recess; and a replacement piece 44 for displaying information closely fitted into a mounting hole 42 provided in the side molding surface 20 without a gap therebetween. The replacement piece 44 is provided in the side piece 26 or in the side mold body 24 so as not to span the side piece 26 and the side mold body 24.

Die (1) representing a tread pattern model for a tread of a tire to be molded. The die is made up of a plurality of blocks (2) separated by grooves (4), at least a part of the die having surfaces provided with textures (5).