Tire molding die

Abstract

To provide a tire molding die capable of reducing a driving force necessary for driving a segment in an initial tire release.SOLUTION: A tire molding die 100 includes a die part 40, a holder 41 that supports the die part 40, a ring-shaped tread molding part 3 divided into multiple segments 4 arranged in a circumferential direction, an outer ring 7 that is positioned outside in a radial direction of a ring of the tread molding part 3 and moves along an axial direction of the ring of the tread molding part 3 to open and close the tread molding part 3 in the radial direction, the holder 41 is arranged on the outer side in the radial direction compared to the die part 40, and has, on an outside surface 44 in the radial direction, a guide groove 45 along the vertical direction that is engaged with the outer ring 7, the outer ring 7 has its axis overlapping with a shaft center G of the tread molding part 3 and has a guiding portion 74 that engages the guide groove 45 on its inner surface side and along a vertical direction, as well as a rotation mechanism 77 that allows rotation of the guiding portion 74 in the radial direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tire molding mold. [Background technology]

[0002] Conventionally, as a tire molding mold used when manufacturing a tire by vulcanizing and molding an unvulcanized raw tire, there has been known a tire molding mold in which a circular tread molding portion (tread mold) that molds the tire tread is divided into a plurality of segments arranged in the circumferential direction, and each segment is configured to open and close by moving in the radial direction (see, for example, Patent Documents 1 to 3).

[0003] However, with the above-mentioned conventional tire molding molds, when the tire is released from the tread molding section after vulcanization molding, each segment moves radially outward while maintaining its orientation relative to the tire tread. This causes the tread design surface that molds the tread of each segment, i.e., the entire surface of the mold, to simultaneously peel off from the tread, resulting in the problem that a large driving force is required to drive the segments until they are released from the tire.

[0004] For example, in the initial stage of tire demolding, it is necessary to peel the segment mold from the tread and also to remove the segment protrusions (sipe molds) corresponding to the pattern from the tire's design surface pattern. Therefore, when the segment mold is peeled from the tread, a large driving force is required to release the adhesion between the mold surface and the tread. In addition, there was a problem that a large driving force was required to drive the segment due to undercut resistance when the segment protrusions corresponding to the pattern are removed from the tire's design surface pattern until the segment is demolded from the tire.

[0005] Patent Document 4 discloses a tire molding die that includes an annular tread molding portion divided into multiple segments arranged in the circumferential direction, and a tilting mechanism that tilts the segments radially outward when the tread molding portion is opened radially outward, the tilting mechanism returning the inclination of the segments to their original position after the tread molding portion is opened. It is said that this tire molding die can reduce the driving force required to drive the segments in the initial stage of tire demolding by tilting the segments radially outward when the tread molding portion is opened radially outward. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2000-326332 A [Patent Document 2] JP 2000-334740 A [Patent Document 3] JP 2009-149079 A [Patent Document 4] JP 2023-68580 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the prior art disclosed in Patent Document 4, the inclination of the segments including the mold is controlled in a standard manner, and it is not possible to obtain an optimal inclination state according to, for example, the type of tire, individual differences, or changes in the state of the tire due to fluctuations in the manufacturing environment, and it is not possible to sufficiently reduce the driving force required to drive the segments in the early stage of tire demolding. Therefore, there is still a need to provide a tire molding mold that can reduce the driving force required to drive the segments in the early stage of tire demolding.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and an object of the present invention is to provide a tire molding die that can reduce the driving force required to drive the segments in the initial stage of tire demolding. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a tire molding mold, A ring-shaped tread molding section including a mold section for forming a tread of a tire and a holder for supporting the mold section, the ring-shaped tread molding section being divided into a plurality of segments arranged in a circumferential direction; an annular outer ring that is disposed radially outside the ring of the tread molding portion and moves along the axial direction of the ring of the tread molding portion to move the segments in the radial direction, thereby opening and closing the tread molding portion in the radial direction, The holder includes: Located radially outward of the mold part, a first rail portion that engages with the outer ring and extends in a vertical direction on an outer surface in the radial direction; The outer ring is The axis of the ring overlaps with the axis of the ring of the tread molding portion, The inner surface has a second rail portion that engages with the first rail portion of each holder and extends in the up-down direction, and a rotation mechanism that allows the second rail portion to rotate in the radial direction.

[0010] In the tire molding mold according to the present invention, the outer ring has an elastic member that biases the second rail portion outward in the radial direction, The rotation mechanism is disposed along a circumferential direction of the ring of the tread molding portion, The elastic member and the pivot mechanism may be disposed at different positions in the up-down direction.

[0011] In the tire molding mold according to the present invention, The movable rail may further include a restricting portion that restricts a rotation range of the second rail portion.

[0012] In the tire molding mold according to the present invention, Regarding the magnitude of play in the radial direction between the pair of engaging first rail portions and second rail portions, the magnitude of the play in one pair may be different from the magnitude of the play in another pair. Effect of the Invention

[0013] According to the present invention, it is possible to reduce the driving force required to drive the segments in the initial stage of tire demolding. [Brief description of the drawings]

[0014] [Figure 1] FIG. 2 is a cross-sectional view of the tire molding die according to the present embodiment as seen from the front. [Diagram 2] FIG. 2 is a cross-sectional view of a tread molding portion in a plan view. [Diagram 3] FIG. 2 is a cross-sectional front view of a main portion of a tire mold in a closed state. [Figure 4] FIG. 2 is a cross-sectional front view of a main portion of a tire mold in a state in which the mold is beginning to open. [Diagram 5] FIG. 2 is a cross-sectional front view of a main portion of a tire mold in an open state. [Figure 6] FIG. 2 is a cross-sectional front view of a main portion of a tire mold immediately prior to closing. [Figure 7] FIG. 4 is a cross-sectional view of a main portion of another tire molding die. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] A tire molding die according to an embodiment of the present invention will be described with reference to the drawings.

[0016] First embodiment FIG. 1 shows a cross-sectional front view of a tire molding die 100 according to this embodiment (hereinafter, may be referred to as die 100).

[0017] (Summary) The mold 100 is used for manufacturing a tire 200 by molding a green tire, which is mainly made of unvulcanized (before vulcanization) synthetic rubber, into a predetermined shape while vulcanizing the green tire.

[0018] The mold 100 includes a mold section 40 for forming the tread of the tire 200, a holder 41 for supporting the mold section 40, an annular tread molding section 3 divided into a plurality of segments 4 arranged in the circumferential direction, and an outer ring 7 arranged radially outside the ring of the tread molding section 3 and moving along the axial direction of the ring of the tread molding section 3 to move the segments 4 in the radial direction, thereby opening and closing the tread molding section 3 in the radial direction. The holder 41 is arranged radially outside the mold section 40, and has a guide groove 45 (an example of a first rail portion) on an outer surface 44 in the radial direction that engages with the outer ring 7 and extends in the vertical direction. The axis of the outer ring 7 overlaps with the axis G of the ring of the tread molding section 3, and has guide sections 74 (an example of a second rail portion) on the inner side that engage with the guide grooves 45 of the holders 41 and extend in the vertical direction, and a rotation mechanism 77 that allows the guide sections 74 to rotate in the radial direction.

[0019] In the mold 100, it is possible to reduce the driving force required to drive the segments 4 in the initial stage of demolding of the tire 200. In the mold 100, the rotary mechanism 77 allows the guide portion 74 to rotate in the radial direction, so that the segments 4 open in the radial direction as the outer ring 7 moves, and the guide portion 74 rotates in the radial direction due to the resistance when the mold portion 40 is demolded from the tread surface of the tire 200. As a result, the segments 4 are tilted via the guide groove 45 that engages with the guide portion 74, so that the driving force required to drive the segments 4 in the initial stage of demolding is reduced.

[0020] (Detailed explanation) The mold 100 will now be described in detail.

[0021] The mold 100 includes a lower container 1, an upper container 2, a tread molding portion 3, and an outer ring 7 (hereinafter, referred to as the ring 7). As described above, the tread molding portion 3 is formed in an annular shape.

[0022] Hereinafter, the direction along the axis G of the tread molding portion 3 is referred to as the axial direction. The circumferential direction of the tread molding portion 3 and the same direction are simply referred to as the circumferential direction. The radial direction of the tread molding portion 3 and the same direction are simply referred to as the radial direction, and the outer side in the radial direction may be simply referred to as the outer side, and the inner side in the radial direction may be simply referred to as the inner side. In the axial direction, the direction facing the upper container 2 as viewed from the lower container 1 is referred to as the upper side, upward, or top, and the direction facing the lower container 1 as viewed from the upper container 2 is referred to as the lower side, downward, or bottom. In this embodiment, the top view refers to the viewpoint when looking down from above along the axial direction.

[0023] The lower container 1 is a seat for the mold 100. The upper container 2 and the tread molding section 3 are placed on the lower container 1. The lower container 1 has a plate section 10 and a lower sidewall molding section 11 placed on the upper surface of the plate section 10.

[0024] The upper container 2 has a plate portion 20 and an upper sidewall molding portion 21 fixed to the lower surface of the plate portion 20. The upper container 2 supports a ring 7 by suspending it. In this embodiment, the ring 7 is suspended from the upper container 2 with its upper end portion fixed to a position outside the upper sidewall molding portion 21. The upper container 2 is capable of moving up and down relative to the lower container 1 along the axial direction.

[0025] The lower sidewall molding portion 11 and the upper sidewall molding portion 21 are dies that form the side portions (sidewalls) of the tire 200. The lower sidewall molding portion 11 and the upper sidewall molding portion 21 are formed in annular shapes that are coaxial with the tread molding portion 3. The upper surface of the lower sidewall molding portion 11 and the lower surface of the upper sidewall molding portion 21 are design surfaces that mold the side surfaces of the tire 200.

[0026] The tread molding section 3 is a unit including a mold for forming the tread surface of the tire 200. The inner surface of the tread molding section 3 is a design surface that forms the tread surface of the tire 200. The tread molding section 3 is placed directly on the upper surface of the plate section 10 of the lower container 1.

[0027] Fig. 2 shows a cross-sectional plan view (top view) of the tread mold portion 3. As shown in Fig. 2, the tread mold portion 3 is divided into a plurality of segments 4 arranged in the circumferential direction.

[0028] The tread mold portion 3 may be divided into, for example, 5 to 90 segments 4 in the circumferential direction. As shown in FIG. 1, the segments 4 may be placed directly on the upper surface of the plate portion 10 of the lower container 1. FIG. 2 illustrates an example in which the tread mold portion 3 is divided into nine segments 4 each having the same circumferential length. The inner surface of the segments 4 is the design surface of the tread mold portion 3. Hereinafter, the inner surface of the segments 4 may be referred to as the design surface of the segments 4.

[0029] The segment 4 is movable between a closed position (see FIG. 2) where the design surface of the segment 4 is continuous with the design surface of another segment 4 adjacent in the circumferential direction, and an open position where the design surface of the segment 4 is discontinuous with the design surface of the other adjacent segment 4. In other words, the open position of the segment 4 is a position outside the closed position of the segment 4. The segment 4 is movable, for example, along the radial direction between the open position and the closed position.

[0030] 3 to 6 show cross-sectional views of the main parts of the mold 100 as viewed in the circumferential direction. FIG. 3 shows the case where the segments 4 are in the closed position, and FIG. 4 to FIG. 6 show the case where the segments 4 are in the open position. The ring 7 is disposed on the outer side and upper side of the tread molding section 3. The ring 7 engages with each of the segments 4. The ring 7 moves the segments 4 to the closed position (see FIG. 3) and the open position (see FIG. 4 to FIG. 6). The ring 7 is movable between a holding position (see FIG. 3) in which the segments 4 are held in the closed position, and a release position (see FIG. 4 to FIG. 6) in which the segments 4 are in the open position. FIG. 4 shows a cross-section of the mold 100 when the segments 4 start to open. FIG. 5 shows a cross-section of the mold 100 when the segments 4 are further opened from the state shown in FIG. 4. FIG. 6 shows a cross-section of the mold 100 immediately before the segments 4 are closed.

[0031] In this embodiment, the ring 7 rises and falls as the upper container 2 rises and falls. The ring 7 may be raised and lowered by an elevator (not shown). In this embodiment, the holding position is the position at which the ring 7 is lowest. Also, the release position is a position at which the ring 7 is higher than the holding position. The ring 7 and the operation associated with the engagement between the ring 7 and the segment 4 will be described later.

[0032] 3 to 6, the segment 4 has a mold part 40 whose inner surface is a design surface that forms the tread surface of the tire 200, and a holder 41 that supports the mold part 40. The mold part 40 and the holder 41 are disposed on the inner side and below the ring 7.

[0033] The mold section 40 has protrusions on its design surface that form grooves in the tire tread and protrusions that form sipes. The protrusions on the design surface of the mold section 40 may be provided in any shape according to the desired shape of the tread or the sipe. The ends of the mold section 40 in the circumferential direction are shaped to match the ends of the adjacent mold sections 40.

[0034] The holder 41 is disposed adjacent to the outside of the mold part 40, and supports the outer part of the mold part 40. The inner part of the holder 41 is formed, for example, in a concave shape in which the inner part in the axial direction is recessed outward more than both axial ends, and the mold part 40 is supported by the holder 41 with its outer part fitted into the recess.

[0035] The outer surface 44 of the holder 41 is an inclined surface in which the upper end side of the holder 41 is located more inward than the lower end side. The outer surface 44 is an arc-shaped surface along the circumferential direction when viewed from above (see FIG. 2). A guide groove 45 (an example of a first rail portion) is formed on the outer surface 44, extending linearly along the up-down direction from the lower end to the upper end of the outer surface 44. The guide groove 45 has a so-called T-slot (dovetail) shape in which the circumferential width of the opening on the upper surface of the groove (the opening along the up-down direction formed on the outer surface 44) is smaller than the circumferential width of the bottom part (inner part) of the groove. The guide groove 45 engages with the ring 7, as described later.

[0036] The inner surfaces of the upper and lower ends of the holder 41 face the outer surfaces of the upper sidewall molding portion 21 and the lower sidewall molding portion 11, respectively.

[0037] The holder 41 may move between the open position and the closed position while being placed on the upper surface of the plate portion 10 of the lower container 1. The holder 41 may be spaced apart from the upper surface of the plate portion 10 in the open position (see FIG. 5).

[0038] 1, the ring 7 has a cylindrical shape with the axis G as the center of the cylinder. The ring 7 engages with an outer surface 44 or a guide groove 45 of a holder 41 which is an outer portion of the segment 4.

[0039] 3 to 6, the ring 7 has an inner peripheral portion 72 on which a ring inner inclined surface 73 is formed, the ring inner inclined surface 73 facing inward and inclining so that the diameter gradually decreases toward the top. The ring inner inclined surface 73 faces inward, is inclined linearly with respect to the axial direction, and is an arc-shaped surface along the circumferential direction so that the upper end side is located more inward than the lower end side.

[0040] The ring inner circumference 72 is provided with a rail-shaped guide portion 74 (an example of a second rail portion) that runs along the vertical direction and along the ring inner inclined surface 73, a rotation mechanism 77 that allows the guide portion 74 to rotate radially, and a biasing portion 8 that biases the guide portion 74 outward.

[0041] The rotation mechanism 77 may have, for example, a bearing portion arranged along the circumferential direction. The rotation mechanism 77 has a through hole or a groove formed along the circumferential direction as an example of a bearing portion. The rotation mechanism 77 may be arranged at the upper end or the lower end of the ring inner circumferential portion 72. In the present embodiment, as an example, the case where the rotation mechanism 77 is a groove arranged at the upper end of the ring inner circumferential portion 72 is shown.

[0042] The guide portions 74 are arranged in the circumferential direction at the same intervals as the intervals between adjacent segments 4 in the circumferential direction, and in the same number as the segments 4.

[0043] The guide portion 74 has a rotating portion 75 at its upper or lower end, which fits into a groove of the rotating mechanism 77 and has a rotating shaft 76 that serves as the center of rotation. In this embodiment, the rotating portion 75 is disposed at the upper end of the guide portion 74. The rotating portion 75 extends outward from the upper end of the guide portion 74. The rotating shaft 76 is, for example, a rod-shaped shaft member that runs along the radial direction. The rotating shaft 76 of the guide portion 74 is rotatably supported by the rotating mechanism 77, and the guide portion 74 is allowed to rotate toward and away from the ring inner inclined surface 73, i.e., to rotate in the radial direction.

[0044] The guide portion 74 has a T-shaped cross section when viewed along the extending direction. In other words, the guide portion 74 has a wider circumferential width on the side away from the ring inner circumferential portion 72 than on the side close to the ring inner circumferential portion 72. When no inward external force is applied to the guide portion 74, the guide portion 74 is disposed so as to extend from the lower end to the upper end of the ring inner circumferential portion 73 along the ring inner circumferential portion 72 in a state of contact with the ring inner circumferential portion 73. Hereinafter, the position of the guide portion 74 in a state of contacting and along the ring inner circumferential portion 73 may be referred to as the initial position.

[0045] Each guide portion 74 fits into the guide groove 45 of the segment 4 at the same position in the circumferential direction, and engages with it so as to be able to tow the segment 4 outward. In this embodiment, with the lower surface of the cross bar portion of the T-shaped guide portion 74 (the outer surface 74a of the guide portion 74) abutting against the lower surface of the cross bar portion of the T-shaped guide groove 45 (the inner surface 45a of the guide groove 45), the guide portion 74 engages with the guide groove 45 so as to be able to tow the segment 4 outward.

[0046] As an example, the biasing portion 8 may include an elastic member 81 having an inner end supported on the ring outer circumferential portion 70, a through hole 82 formed in the ring 7 along the radial direction, and a pin member 85 having at least a portion inserted into the through hole 82, an inner end connected to the guide portion 74, and an outer end biased outward by the elastic member 81.

[0047] The biasing portion 8 is disposed at a different position in the up-down direction from the rotation mechanism 77, and is disposed at the lower end of the ring 7 in this embodiment.

[0048] The elastic member 81 may be, for example, a coil spring. When the elastic member 81 is a coil spring, the elastic member 81 may be disposed such that the axial direction of the coil is aligned with the radial direction.

[0049] The diameter (inner diameter) of the through hole is larger than the diameter of the pin member 85. This allows the pin member 85 to swing in the axial direction of the through hole within the through hole .

[0050] The hole shape of the through hole 82 may be, for example, a circular shape or an elliptical shape. If the hole shape of the through hole 82 is, for example, an elliptical shape, the pin member 85 can easily swing along the major axis of the elliptical shape.

[0051] A step portion 82a having a stepped structure in which the diameter of the inner portion is narrower than that of the outer portion may be formed in the through hole 82. In this embodiment, the elastic member 81 has an inner end supported by the step portion 82a in a state in which at least a portion of the elastic member 81 is inserted into the through hole 82, and biases the pin member 85 outward.

[0052] The pin member 85 is, for example, a bolt having a bolt head 85a. In this embodiment, the pin member 85 is, for example, a bolt having a bolt head 85a. The pin member 85 is inserted through the through hole 82. The pin member 85 is also inserted through the inside of a coil of an elastic member 81, which is a coil spring. The pin member 85 has an inner end connected (for example, screw-connected) to the guide portion 74, and the inner surface of the bolt head 85a is biased outward by the elastic member 81. As a result, the guide portion 74 is biased outward by the elastic member 81 via the pin member 85.

[0053] The operation of the ring 7 and the segments 4 is as follows: When the upper container 2 descends, the ring 7 descends accordingly, causing the ring inner inclined surface 73 to come into contact with the outer surface 44 of the holder 41, urging the outer surface 44 inward toward the closed position, and moving the segments 4 inward (see FIG. 6).

[0054] When the ring 7 is in the holding position, the ring inner inclined surface 73 abuts against the outer surface 44 to hold the outer surface 44 in the closed position (see FIG. 3).

[0055] Furthermore, when the ring 7 rises from the holding position, the ring 7 pulls the segments 4 outward or upward via the guide grooves 45 on the outer surface 44 (see Figs. 4 and 5). Specifically, this is as follows.

[0056] When the upper container 2 rises, the ring 7 rises accordingly. As a result, the guide groove 45 slides downward and outward relative to the guide portion 74, as shown in FIG.

[0057] As the guide groove 45 slides downward relative to the guide portion 74, the guide portion 74 of the ring 7 pulls the guide groove 45 of the segment 4 outward. As a result, as the guide groove 45 slides downward relative to the guide portion 74, the segment 4 is pulled outward by the ring 7 via the guide portion 74 and the guide groove 45 and moves. When the segment 4 is opened, it moves away from the adjacent segment 4. In other words, as the ring 7 rises, the segments 4 spread out radially along the radial direction, and the tread molding portion 3 opens in the radial direction.

[0058] When the segment 4 is pulled outward by the ring 7 and moves, the resistance generated when the mold portion 40 is peeled off from the tread of the tire 200 (hereinafter referred to as mold release resistance) and the undercut resistance generated when the sipe mold on the design surface of the mold portion 40 comes out of the sipes in the tread of the tire 200 act on the segment 4 as a reaction force to the pulling force. As a result, an inward pulling force acts on the guide portion 74 via the guide groove 45. When the guide portion 74 is pulled, the guide portion 74 rotates by the rotating mechanism 77, and the lower end side moves away from the ring inner inclined surface 73 against the biasing force of the elastic member 81.

[0059] The rotation range of the guide portion 74 increases as the depth of the step portion 82a in the through hole 82 increases, and decreases as the depth of the step portion 82a in the through hole 82 decreases. That is, the rotation range of the guide portion 74 can be restricted by adjusting the installation depth of the step portion 82a in the through hole 82 (an example of a restricting portion).

[0060] The rotation range of the guide portion 74 may be set by disposing a restricting member (another example of a restricting portion) that restricts the rotation of the guide portion 74. Figs. 3 to 6 show a case where a stopper 79 (another example of a restricting portion) is disposed as a restricting member at the upper end of the ring 7. The stopper 79 is disposed above the rotation mechanism 77 and the rotating portion 75. The inner end of the stopper 79 is disposed so as to overlap with the rotating portion 75 in a top view. The guide portion 74 is permitted to rotate within a range until the rotating portion 75 abuts against the lower surface of the stopper 79.

[0061] 4, by rotating the guide portion 74 so as to move away from the ring inner inclined surface 73, the upper end side of the guide portion 74 is raised outward compared to the initial posture. Due to this change in posture of the guide portion 74, the upper end side of the segment 4 is pulled outward via the guide portion 74 and the guide groove 45, and the upper end side moves and inclines more outward than the lower end side.

[0062] Due to this inclination, the mold section 40 moves outward while inclining the upper end side outward with respect to the tread of the tire 200, that is, while gradually releasing (peeling) from the tread from the upper part to the lower part of the mold section 40, so that the maximum value of the mold release resistance can be reduced. Also, it is possible to reduce the undercut resistance when the protrusions (sipes) of the mold section 40 corresponding to the design surface pattern (tread pattern) of the tire 200 come out of this pattern. As a result, it is possible to reduce the driving force required to drive the segments 4 in the early stage of releasing the tire 200 from the mold.

[0063] In this embodiment, the inclination state of the segments 4 when the tread molding portion 3 is opened in the radial direction automatically changes according to the magnitude of the demolding resistance and the undercut resistance. Specifically, if the demolding resistance or the undercut resistance increases, the inclination of the segments 4 increases, and thus the demolding resistance and the undercut resistance are automatically adjusted to be smaller. Therefore, compared to the case where a predetermined inclination state is achieved at a predetermined timing or position, the driving force required to drive the segments in the early stage of demolding of the tire 200 can be further reduced.

[0064] As shown in Fig. 5, after the mold section 40 is completely released from the tread, the guide section 74 returns to its initial position due to the biasing force of the elastic member 81. Note that Fig. 5 shows a state in which the ring 7 further rises after the mold section 40 is completely released from the tread, and the segment 4 is suspended by the ring 7.

[0065] As described above, the guide portion 74 returns to the initial position after the mold portion 40 is completely released from the tread, so that when the ring 7 descends again toward the holding position, the guide portion 74 is in the initial position. Therefore, when the ring 7 descends again toward the holding position, the segments 4 are moved inward with the guide portion 74 in the initial position (see FIGS. 6 and 3).

[0066] In this manner, the ring 7 moves the segments 4 between the closed and open positions to radially open and close the tread molding portion 3. Then, the segments 4 are pulled open in the radial direction as the ring 7 moves, and when the mold portion 40 is released from the tread surface of the tire 200, the segments 4 are inclined together with the guide portion 74, so that the driving force required to drive the segments 4 in the initial stage of release is reduced.

[0067] (Modification) As described in the above embodiment, the guide portion 74 of the ring 7 fits into the guide groove 45 and engages with it so as to be able to pull the segment 4 outward. Since the guide groove 45 and the guide portion 74 slide relative to each other, a predetermined gap is necessary as play at the sliding contact portion between the guide groove 45 and the guide portion 74.

[0068] For example, regarding the size of the play in the radial direction in a pair of the guide grooves 45 and the guide portions 74 that engage with each other (hereinafter simply referred to as the size of the play), if the size of the play between a certain pair of the guide grooves 45 (the guide grooves 45 of the first segment 4) and the guide portion 74 is made different from the size of the play between another pair of the guide grooves 45 (the guide grooves 45 of the second segment 4) and the guide portion 74, the timing at which the guide groove 45 of the first segment 4 starts to be pulled by the engaged guide portion 74 can be made different from the timing at which the guide groove 45 of the second segment 4 starts to be pulled by the engaged guide portion 74, so that the driving force required to drive the segments in the initial stage of demolding of the tire 200 can be further reduced in some cases. Note that an example of the size of the play is the distance between the inner surface of the guide portion 74 and the outer surface of the guide groove 45 when the ring inner inclined surface 73 abuts against the outer surface 44 of the holder 41 and biases the outer surface 44 inward toward the closed position. Figure 7 shows a case in which the distance t between the outer surface 74a of the guide portion 74 and the inner surface 45a of the guide groove 45 when the ring inner inclined surface 73 abuts against the outer surface 44 of the holder 41 and urges the outer surface 44 inward toward the closed position is larger than the distance t in the case of Figure 3.

[0069] In this manner, it is possible to provide a tire molding die that can reduce the driving force required to drive the segments in the initial stage of tire demolding.

[0070] [Another embodiment] (1) In the above embodiment, the ring inner circumferential portion 72 has the biasing portion 8 that biases the guide portion 74 outward. However, the biasing portion 8 is not essential and can be omitted.

[0071] (2) In the above embodiment, an example was described in which a stopper 79 for restricting the rotation range of the guide portion 74 is disposed at the upper end of the ring 7. However, the stopper 79 is not essential and can be omitted.

[0072] (3) In the above embodiment, the rotating mechanism 77 is disposed at the upper end of the ring inner circumferential portion 72, and the rotating portion 75 is disposed at the upper end of the guide portion 74. However, the rotating mechanism 77 and the rotating portion 75 may be disposed at the lower end of the ring inner circumferential portion 72 and the lower end of the guide portion 74, respectively. In the case of such an arrangement, the direction of inclination of the segments 4 when the tread molding portion 3 is opened in the radial direction is opposite to that described in the above embodiment, and the lower end side of the segments 4 is pulled outward via the guide portion 74 and the guide groove 45, and the lower end side moves and inclins more outward than the upper end side.

[0073] (4) In the above embodiment, a case has been described in which the rotating mechanism 77 has a bearing portion such as a through hole or a groove, and the guide portion 74 has the rotating shaft 76 such as a shaft member in the rotating portion 75. However, the relationship between the rotating mechanism 77 and the rotating portion 75 may be reversed. That is, the rotating portion 75 may have a bearing portion such as a through hole or a groove, and the rotating mechanism 77 may have a shaft member that is axially supported by the bearing portion.

[0074] In addition, the configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradiction arises. Furthermore, the embodiments disclosed in this specification are illustrative, and the embodiments of the present invention are not limited thereto, and can be appropriately modified within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0075] The present invention is applicable to tire molding dies. [Explanation of symbols]

[0076] 1: Lower container 10: Board part 100: Mold (tire mold) 11: Lower sidewall molding 2: Upper container 20: Board part 200: Tire 21: Upper sidewall molding 3: Tread molding section 4: Segment 40: Mold section 41: Holder 44:Outer surface 45: Guide groove (first rail part) 45a: face 7: Ring (outer ring) 70: Ring outer circumference 72: Inner circumference of ring 73: Inner inclined surface of the ring (inner surface) 74: Guide part (second rail part) 74a :face 75: Rotating part 76: Rotating shaft 77: Rotating mechanism 79: Stopper 8: Pressurizing section 81: Elastic member 82: Through hole 82a: Stepped section 85: Pin member 85a: Bolt head G: Axial center t: gap

Claims

1. A ring-shaped tread molding section including a mold section for forming a tread of a tire and a holder for supporting the mold section, the ring-shaped tread molding section being divided into a plurality of segments arranged in a circumferential direction; an annular outer ring that is disposed radially outside the ring of the tread molding portion and moves along the axial direction of the ring of the tread molding portion to move the segments in the radial direction, thereby opening and closing the tread molding portion in the radial direction, The holder includes: Located radially outward of the mold part, a first rail portion that engages with the outer ring and extends in a vertical direction on an outer surface in the radial direction; The outer ring is The axis of the ring overlaps with the axis of the ring of the tread molding portion, A tire molding die having, on its inner surface, a second rail portion that engages with the first rail portion of each of the holders and extends in the up-down direction, and a rotation mechanism that allows the second rail portion to rotate in the radial direction.

2. the outer ring has an elastic member that biases the second rail portion outward in the radial direction, The rotation mechanism is disposed along a circumferential direction of the ring of the tread molding portion, 2. The tire mold according to claim 1, wherein the elastic member and the pivot mechanism are disposed at different positions in the up-down direction.

3. The tire mold according to claim 1 or 2, further comprising a restricting portion that restricts a rotation range of the second rail portion.

4. 3. The tire molding mold according to claim 1, wherein the magnitude of play in the radial direction between a pair of engaging first rail portions and second rail portions is different between a pair of engaging first rail portions and another pair of engaging second rail portions.

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