Abstract: An apparatus for manufacturing a pneumatic tire including a rigid core for forming a green tire on an outer face and a vulcanizing mold which can transport the green tire together with the rigid core such that the vulcanizing mold is closed to form a vulcanization space for sealing and storing the green tire between the vulcanizing mold and the rigid core so that the green tire is vulcanized in the vulcanization space, an annular movable seal supported by either one of the vulcanizing mold or the rigid core, and an urging means for urging the movable seal from the one of the vulcanizing mold and the rigid core that supports the annular movable seal toward a surface of the other of the vulcanizing mold and the rigid core, the movable seal being urged by the urging means toward the surface of the other of the vulcanizing mold and the rigid core so as to prevent generation of a gap between the vulcanizing mold and the rigid core when the vulcanizing mold is closed, and to absorb a change in shape of the rigid co

Abstract: A 3-D solid model of a tire vulcanizing mold is constructed on CAD, lamination models the optimum value of the pitch of which is determined in consideration of molding accuracy and processing time are created by dividing this model in a predetermined lamination direction, slice data for each layer corresponding to the lamination pitch of each segment are created, a sector mold of the tire vulcanizing mold is manufactured by a powder sintering method based on the slice data, and the density of a sintered body is controlled by adjusting the output of a laser beam or the exposure time of the laser beam applied to the powders to provide a density distribution on the plane and in the depth direction of a mold element for each layer so as to obtain a tire vulcanizing mold having a hybrid structure.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: A 3-D solid model of a tire vulcanizing mold is constructed on CAD, lamination models the optimum value of the pitch of which is determined in consideration of molding accuracy and processing time are created by dividing this model in a predetermined lamination direction, slice data for each layer corresponding to the lamination pitch of each segment are created, a sector mold of the tire vulcanizing mold is manufactured by a powder sintering method based on the slice data, and the density of a sintered body is controlled by adjusting the output of a laser beam or the exposure time of the laser beam applied to the powders to provide a density distribution on the plane and in the depth direction of a mold element for each layer so as to obtain a tire vulcanizing mold having a hybrid structure.

Abstract: A tire vulcanizing device includes an upper plate and a lower plate which can be relatively displaced toward and away from each other, and a mold for vulcanizing and molding a tire arranged between the upper plate and the lower plate. The mold includes an upper and a lower side mold members arranged on the upper plate side and the lower plate side, respectively, and a plurality of sector mold members arranged between the upper and the lower side mold members. An outer ring for positioning the sector mold members in the radial direction is arranged on the lower plate side. An actuator for opening the sector mold member is arranged on the lower plate, capable of vertical elevation.

Abstract: There is provided a vulcanizing mold for a tire in which the capacity of venting air through between the molding pieces of the sector mold is significantly enhanced. A tread ring for vulcanizing and shaping a tread of the tire comprises plural sector molds which are separately formed in the circumferential direction so as to be brought into surface contact with each other. Each of the sector molds comprises segments and plural movable molding pieces circumferentially aligned and disposed on the inner surface side of the segment, and each of the movable molding pieces of each sector mold is urged away from each other.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: A method for manufacturing a pneumatic tire wherein a green tire formed on the outer surface of a rigid core is transported into a vulcanizing mold together with the rigid core, and the vulcanizing mold is closed to form a vulcanization space for sealing and storing the green tire between the vulcanizing mold and the rigid core. At closure of the vulcanizing mold, an annular movable seal supported by one of the vulcanizing mold and the rigid core is urged toward the surface of the other so as to prevent generation of a gap between the vulcanizing mold and the rigid core at closure of the vulcanizing mold and to absorb change in the shape of the rigid core at vulcanization.

Abstract: A vulcanizing mold for pneumatic tires includes upper and lower base plates, upper and lower sidewall mold members attached to the upper and lower base plates, respectively; and upper and lower tread mold members attached to the upper and lower base plates, respectively. The upper and lower tread mold members are constituted of upper segments and lower segments, respectively. The upper and lower segments can be radially expanded and contracted relative to the upper and lower sidewall mold members, respectively. In operation, the upper and lower sidewall mold members are displaced toward each other so that the upper and lower segments are brought into abutment with each other. Then, a single cam ring is operated to cause all of the segments to be simultaneously displaced radially inwards and relative to the upper and lower sidewall mold members, with the upper segments in abutment with the lower segments.

Abstract: To provide a method of manufacturing a thin rubber member capable of accommodating various-size and manufacturing a thin rubber member having a constant thickness. In the first step, a long rectangular rubber strip having taper portions formed at both end portions in a transverse direction of the long rectangular rubber strip is cut to a predetermined length to thereby form a plurality of segmented rubber strips 36. In the second step, taper portions 36B at both end portions in a transverse direction of the rubber strip 36 are overlapped with one another, and a plurality of the segmented rubber strips 36 is connected to each other in the transverse direction, whereby a rubber sheet 38, the end portions of which are tapered and which has a large area, can be formed. Further, the rubber sheet 38 that can accommodate various sizes can be obtained by changing the length of the segmented rubber strip 36 and the number of connections thereof.

Abstract: A tire vulcanizing device includes an upper plate (1) and a lower plate (2) which can be relatively displaced toward and away from each other, and a mold for vulcanizing and molding a tire arranged between the upper plate and the lower plate. The mold includes an upper and a lower side mold members (3, 12) arranged on the upper plate (1) side and the lower plate (2) side, respectively, and a plurality of sector mold members (13) arranged between the upper and the lower side mold members (3, 12). An outer ring (5) for positioning the sector mold members (13) in the radial direction is arranged on the lower plate (2) side. An actuator means for opening the sector mold member is arranged on the lower plate, capable of vertical elevation.

Abstract: There is provided a vulcanizing mold for a tire in which the capacity of venting air through between the molding pieces of the sector mold is significantly enhanced. A tread ring for vulcanizing and shaping a tread of the tire comprises plural sector molds which are separately formed in the circumferential direction so as to be brought into surface contact with each other. Each of the sector molds comprises segments and plural movable molding pieces circumferentially aligned and disposed on the inner surface side of the segment, and each of the movable molding pieces of each sector mold is urged away from each other.

Abstract: A process for modifying a uniformity of a tire comprising a radial carcass ply of rubberized organic fiber cords is modifications of radial force variation (RFV) and conicity force (COF), which is carried out by dividing RFV- or COF-rejected tire into two portions and applying different thermal hysteresis to these portions under specified conditions.

Abstract: An annular mold having a molding surface for forming a tread pattern of a tire is divided, at least in the peripheral direction, into plural pieces. The plural pieces are disposed adjacent to one another via adjacent surfaces, which are peripheral direction division surfaces, so as to form the annular mold. Substantially an entire molding-surface-side side edge portion of each adjacent surface of the piece is cut-out at a narrow width such that a gap for air venting is formed. Thus, at a low cost, a mold for molding a tire is provided in which there is no spewing, and air can always be reliably vented without a need for applying a vacuum.

Abstract: A mold for tire vulcanization comprises a plurality of segments forming respectively a part of a circular interior complementary to land portions and groove portions of the tread portion of a tire product and being separable from each other in the tire circumferential direction, and each of the segments comprising a plurality of pieces forming said circular interior part and a block supporting the pieces, wherein each of the pieces comprises a combination of a matrix metal and a core made of a different kind of material which is preferably fitted to a through hole of the matrix metal and has a lower coefficient of thermal expansion than that of the matrix metal. In a method of manufacturing the mold, upon casting the matrix metal, the matrix metal is cast around the core with a higher fusion point than that of the matrix metal.

Abstract: A curing mold for pneumatic tires includes a plurality of segments which are detachably adjoined with each other in a direction corresponding to circumferential direction of a product tire. Each segment has a plurality of fitting pieces with fixing portions at both ends at least one which is complementary to part of the land portion of the tire. The fitting pieces are secured to and supported by a supporting block having an inner surface which is complementary to the land and groove portions of the tire, which is formed with fitting grooves for engaging the fixing portions of the fitting pieces therein.

Abstract: An annular metal mold portion forming a tire tread is constructed by assembling a plurality of sector metal molds 2 severed in the circumferential direction, and all or some of the sector metal molds 2 are constructed of a plurality of smaller parts 3 severed in the axial direction as well as in the circumferential direction. Joining surfaces between the sector metal molds themselves each consisting of a plurality of smaller parts are formed of contour surfaces in arbitrary shape of the smaller parts. These contour surfaces are such curved surfaces that at every location a radius of curvature is 5 mm or larger and an inclination angle of a tangential plane with respect to a tire axis is 80 degrees or less.