Tire mold and tire demolding device

Abstract

To provide a mold for molding a tire having a simple structure capable of shifting the opening timing of each segment, and a tire demolding device.SOLUTION: The mold 100 for molding a tire includes an annular tread molding part 3 divided into a plurality of segments 4 arranged in a circumferential direction, a closing drive part 7 arranged on an outer side in a radial direction of the tread molding part 3 and moving the segments 4 to a closing position, and an opening drive part 6 moving a part of the segments 4 among the plurality of segments 4 to an opening position located on an outer side in the radial direction with respect to the closing position, and the opening drive part 6 includes a cam mechanism capable of moving along an axial direction of the tread molding part 3 and moving the segments 4 to the opening position by the movement along the axial direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a tire mold and a tire demolding device. [Background technology]

[0002] Patent Document 1 discloses a segment drive device for a tire mold. This segment drive device for a tire mold engages a segment drive unit and segments that constitute the tire mold's container, and the vertical movement of the segment drive unit acts as a guide to move multiple circumferentially divided segments radially to open and close a tread mold section provided on the inner circumferential surface. In this segment drive device for a tire mold, the multiple segments are divided into two different types, first segments and second segments, and these first segments and second segments are alternately arranged on the lower mold side without being raised or lowered. Drive cylinders are provided in association with the first and second segments, and the drive cylinders move the first segments ahead of the second segments. The drive cylinders are provided corresponding to the first and second segments, respectively, and are configured to allow the first and second segments to move independently. In this tire mold segment drive device, the first and second segments are moved radially separately, either continuously or intermittently, with the first segment always reaching the closed position of the tread mold before the second segment. This prevents the raw tire from getting caught between the segments, making it possible to prevent major flashing and extend the life of the tire mold.

[0003] Patent Document 2 discloses a tire vulcanizing apparatus. This tire vulcanizing apparatus includes a plurality of segment molds (an example of segments) arranged in a ring shape along the tire circumferential direction to mold the tire; a support member that rotatably supports the segment molds toward the outside and inside of the tire radial direction around a rotary support portion connected to one end of the segment mold in the tire width direction; and a movement mechanism that moves the segment mold at least by rotation to position the segment mold between a molding position where the tire is molded and a separation position away from the tire. In this tire vulcanizing apparatus, the movement of the plurality of segment molds may be performed at different timings. Patent Document 2, as an example, illustrates a case in which nine segment molds are moved from the molding position to the separation position in three stages, and discloses a case in which three segment molds are moved to the separation position in sequence until all of the segment molds are positioned at the separation position. In this tire vulcanizing apparatus, it is disclosed that the force acting on the tire is further reduced by moving the plurality of segment molds at different timings. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-334740 [Patent Document 2] Japanese Patent Application Publication No. 2018-202787 Summary of the Invention [Problem to be solved by the invention]

[0005] In the prior art, when staggering the timing at which each segment of a tire mold opens, the structure of the tire mold becomes complex. Furthermore, because the mold structure becomes complex in this way, it is not easy to adjust the staggered timing at which each segment opens. Therefore, it is desirable to provide a tire mold and a tire demolding device with a simple structure that allows the timing at which each segment opens to be staggered.

[0006] The present disclosure has been made in consideration of the above circumstances, and its purpose is to provide a tire molding mold and a tire demolding device with a simple structure that allows the timing of opening each segment to be staggered. [Means for solving the problem]

[0007] The tire mold according to the present disclosure for achieving the above object comprises: an annular tread molding portion divided into a plurality of segments arranged in a circumferential direction; a closing drive unit disposed radially outside the tread molding unit and configured to move the segments to a closed position; an open drive unit that moves some of the plurality of segments to an open position that is located radially outward from the closed position, The opening drive unit is The tread molding portion is movable along the axial direction thereof, A cam mechanism is included that moves the segments to the open position upon movement along the axial direction.

[0008] In the tire mold according to the present disclosure, The closing drive portion may be movable along the axial direction between a holding position that holds the segment in the closed position and a release position that allows the segment to move to the open position.

[0009] In the tire mold according to the present disclosure, The axial direction is along the vertical direction, The opening drive may move upward in the vertical direction to move the segments to the open position.

[0010] In the tire mold according to the present disclosure, The opening drive unit includes the cam mechanism: a segment side cam portion fixed to the segment; a hanging portion that moves the segment-side cam portion outward in the radial direction, The segment-side cam portion may be detachable from the segment.

[0011] In the tire mold according to the present disclosure, The cam mechanism includes: a first rail portion formed on the hanging portion; a second rail portion formed on the segment-side cam portion and engaging with the first rail portion, the first rail portion and the second rail portion are inclined with respect to the axial direction such that an upper end side is positioned radially inward relative to a lower end side, As the first rail portion rises in accordance with the rise of the hanging portion, the second rail portion may slide downward and radially outward relative to the first rail portion, moving the segment to the open position.

[0012] In order to achieve the above object, the tire demolding apparatus according to the present disclosure is configured as follows: an annular tread molding portion divided into a plurality of segments arranged in a circumferential direction; an opening drive unit that moves some of the plurality of segments to an open position that is located radially outward of a closed position where a tire is molded, The opening drive unit is The tread molding portion is movable along the axial direction thereof, A cam mechanism is included that moves the segments to the open position upon movement along the axial direction. [Effects of the Invention]

[0013] According to the present disclosure, it is possible to provide a tire molding mold and a tire demolding device with a simple structure that can stagger the timing at which each segment opens. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a side view of a tire mold according to an embodiment of the present invention. [Figure 2] FIG. 10 is a top view of the lower unit before molding begins. [Figure 3] FIG. [Figure 4] FIG. [Figure 5] FIG. [Figure 6] FIG. 10 is a top view of the lower unit immediately after molding. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10] FIG. 9 is a cross-sectional view taken along the line XX in FIG. 8. [Figure 11] FIG. [Figure 12] FIG. 10 is a top view of the lower unit at an intermediate stage of mold opening. [Figure 13] FIG. 10 is a top view of the lower unit after the mold is opened. [Figure 14] 10A and 10B are diagrams illustrating the movement speed of the segments to the open position and the demolding force. [Figure 15] 10A and 10B are diagrams illustrating the movement speed of the segments to the open position and the demolding force. [Figure 16] FIG. 10 is a top view of a demolding mechanism according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0015] A tire mold and a tire demolding device according to an embodiment of the present disclosure will be described with reference to the drawings.

[0016] Fig. 1 shows a tire mold 100 according to this embodiment. Fig. 1 is a side view of the tire mold 100.

[0017] The tire molding mold 100 (hereinafter sometimes referred to as mold 100) comprises an annular tread molding section 3 divided into a plurality of segments 4 arranged in the circumferential direction, a closing drive unit 7 disposed radially outside the tread molding section 3 and configured to move the segments 4 to a closed position, and an opening drive unit 6 configured to move some of the plurality of segments 4 to an open position positioned radially outside the closed position. The opening drive unit 6 is movable along the axial direction of the tread molding section 3 and includes a cam mechanism that moves the segments 4 to the open position by moving along the axial direction.

[0018] The mold 100 has a simple structure and can stagger the timing at which each segment 4 opens, that is, the timing at which each segment 4 starts to move to the open position. The mold 100 will be described in detail below.

[0019] The mold 100 is used to manufacture a tire 200 (see FIG. 2) by molding a green tire made mainly of unvulcanized (before vulcanization) synthetic rubber into a predetermined shape while vulcanizing it.

[0020] As shown in Fig. 1, the mold 100 includes a tread molding section 3 having a plurality of segments 4, an opening drive section 6, and a closing drive section 7, as well as a lower container 1 and an upper container 2. As shown in Figs. 1 and 2, the tread molding section 3 is divided into a plurality of segments 4 arranged in a circular ring shape aligned in the circumferential direction.

[0021] In the following, the direction along the axis G of the tread molding portion 3 will be referred to as the axial direction. The circumferential direction of the tread molding portion 3 and the same direction will be simply referred to as the circumferential direction. The radial direction of the tread molding portion 3 centered on the axis G and the same direction will be simply referred to as the radial direction, and the outer side in the radial direction will sometimes be simply referred to as the outer side or the radial outer side, and the inner side will sometimes be simply referred to as the radial inner side.

[0022] 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 up-down direction is along the vertical direction, and the up-down direction may be the same as the vertical direction. In other words, the downward direction in the up-down direction may be the same as the downward direction in the vertical direction, and the upward direction in the up-down direction may be the same as the upward direction in the vertical direction.

[0023] In this embodiment, a front view refers to a viewpoint when viewed along the radial direction.

[0024] In Fig. 1, the circumferential direction is shown as direction C. Furthermore, the upward direction in the axial direction is shown as direction U, the downward direction in the axial direction is shown as direction L, the inner side in the radial direction is shown as direction R1, and the outer side in the radial direction is shown as direction R2.

[0025] 1, the lower container 1, the tread molding unit 3, the closing drive unit 7, and the upper container 2 may be collectively referred to as a molding mechanism. Also, the lower container 1, the tread molding unit 3, and the opening drive unit 6 may be collectively referred to as a demolding mechanism (an example of a tire demolding device).

[0026] In the following description, the lower container 1 and the tread molding section 3 of the mold 100 may be collectively referred to as a lower unit. For example, Fig. 2 is a top view of the lower unit.

[0027] 3 to 5 show cross-sectional views of the molding mechanism. The cross sections shown in Fig. 3 to 5 overlap with the axis G and the center of a certain segment 4 in the circumferential direction.

[0028] As shown in Figures 3 to 5, 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.

[0029] 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 may be raised and lowered by an elevator (not shown). The upper container 2 can be raised and lowered up and down relative to the lower container 1 along the axial direction.

[0030] The lower sidewall molding portion 11 and the upper sidewall molding portion 21 are molds that form the side surfaces (sidewalls) of the tire 200. The lower sidewall molding portion 11 and the upper sidewall molding portion 21 are formed in an annular shape that is 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.

[0031] The tread molding section 3 is a unit including a mold that forms 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.

[0032] As described above, the tread molding portion 3 is formed in an annular shape, as shown in Fig. 2. The tire 200 is placed inside the ring of the tread molding portion 3.

[0033] The tread molding portion 3 has a plurality of segments 4 arranged in the circumferential direction. The tread molding portion 3 may be divided into, for example, 5 to 90 segments 4 in the circumferential direction. In this embodiment, a case where the tread molding portion 3 is divided into eight segments 4 is described as an example. The segments 4 are placed directly on the upper surface of the plate portion 10 of the lower container 1. The tread molding portion 3 of this embodiment is configured, as an example, to be divided into eight segments 4 having the same circumferential length. The inner surface of the segments 4 is the design surface of the tread molding portion 3. Hereinafter, the inner surface of the segments 4 may be referred to as the design surface of the segments 4.

[0034] As shown in Figures 4 to 10, the segment 4 can be moved between a closed position (see Figures 4 to 10) in which the design surface of the segment 4 is continuously connected to the design surface of an adjacent segment 4 in the circumferential direction, and an open position (Figures 2, 3, and 11 to 13) in which the design surface of the segment 4 is discontinuous with the design surface of an adjacent segment 4. The open position of the segment 4 is a position outside the closed position of the segment 4. The segment 4 can be moved radially between the open position and the closed position. Note that Figures 11 and 12 show a state in which only some of the segments 4 (two segments 4) are in the open position, and the other segments 4 are in the closed position.

[0035] As will be described later, the segments 4 are moved to the closed position by the closing drive 7 (see FIGS. 3 and 4), and to the open position by the opening drive 6 (see FIGS. 8 to 11), as will be described later.

[0036] As shown in Figures 2 to 4, the segment 4 has a mold section 40 whose inner surface is a design surface that forms the tread surface of the tire 200, a holder 41 that supports the mold section 40, and a container 42 that holds the holder 41. The holder 41 and the container 42 may be integrated. In the segment 4, the mold section 40, the holder 41, and the container 42 are arranged in this order from the inside to the outside in the radial direction. The mold section 40, the holder 41, and the container 42 are fixed by bolts or the like to form an integrated segment 4.

[0037] The mold section 40 has, on its design surface, protrusions that form grooves in the tread of the tire 200 and protrusions that form sipes. The protrusions on the design surface of the mold section 40 may be provided in any shape to match the desired shape of the tread or the shape of the sipes. The ends of the mold section 40 in the circumferential direction are shaped to follow the ends of the adjacent mold section 40.

[0038] The outer surface 44 of the segment 4 (container 42) is an inclined surface in which the upper end side of the segment 4 is positioned more inward than the lower end side. The outer surface 44 is an arc-shaped surface along the circumferential direction.

[0039] A fixing groove 45 is formed on the outer surface 44, extending linearly in the vertical direction from the lower end to the upper end of the outer surface 44. A guide plate portion 65 (see FIG. 1) is attached to the fixing groove 45, as will be described later.

[0040] As shown in FIGS. 3 and 4, the inner surfaces of the upper and lower ends of the segment 4 face the outer surfaces of the upper sidewall molding portion 21 and the lower sidewall molding portion 11, respectively, in the radial direction.

[0041] The segment 4 moves between an open position and a closed position along the radial direction while being placed on the upper surface of the plate portion 10 of the lower container 1. The segment 4 may move between the open position and the closed position while being guided by a guide groove 14, for example. The guide groove 14 may be formed on the plate portion 10 along the radial direction. The segment 4 may have, at its bottom, a protruding guided portion 49 that protrudes downward, for example, and that is engaged with and guided by the guide groove 14.

[0042] In this embodiment, the segment 4 is permitted to move in the radial direction but prohibited from moving in the axial direction due to engagement of the guided portion 49 with the guide groove 14. In this embodiment, the guide groove 14 may have a so-called T-slot (dovetail) shape in which the circumferential width of the opening of the upper surface of the groove (the upper portion of the groove in the axial direction) is smaller than the circumferential width of the bottom portion of the groove (the lower portion in the axial direction). The guided portion 49 may have a T-shaped cross section as viewed in the radial direction (a shape in which the circumferential width of the lower portion in the axial direction is wider than the circumferential width of the upper portion in the axial direction).

[0043] The closing drive unit 7 is disposed outside and above the tread molding unit 3. The closing drive unit 7 is a member for moving the segments 4 to the closed position and for holding the segments 4 in the closed position.

[0044] The closing drive unit 7 is formed in an annular shape (in this embodiment, annular) when viewed from above. The closing drive unit 7 has a cylindrical shape with the axis G as the center of the cylinder. The closing drive unit 7 has an inner inclined surface 74 that faces inward and is inclined so that the diameter gradually decreases toward the top. The inner inclined surface 74 faces inward and is an arc-shaped surface that is inclined linearly with respect to the axial direction so that the upper end side is located more inward than the lower end side, and that follows the circumferential direction. The inner inclined surface 74 engages with the outer surface 44 of the holder 41, which is the outer portion of the segment 4.

[0045] The closing drive unit 7 is movable between a holding position (see FIGS. 4 to 10) in which the segment 4 is held in the closed position, and a release position (see FIG. 5) in which the segment 4 is allowed to move to the open position.

[0046] In this embodiment, the closing drive unit 7 rises and falls as the upper container 2 rises and falls. The upper container 2 and the closing drive unit 7 may be raised and lowered by a separately provided elevator (not shown). In this embodiment, the holding position is the lowest position of the closing drive unit 7. The release position is a position where the lower end of the closing drive unit 7 is higher than the upper end of the tread molding section 3 (segment 4). The closing drive unit 7 and the operation associated with the engagement between the closing drive unit 7 and the segment 4 will be described later.

[0047] 7, 8, 9, and 11 is a member that moves upward in the vertical direction to move some of the multiple segments 4 to an open position that is located radially outward from the closed position. As will be described later, the opening drive unit 6 includes a cam mechanism that moves the segments 4 to the open position. Note that the cam mechanism in this embodiment is a mechanical element that changes the direction of movement, and its form is not important.

[0048] 8, 9, and 11 illustrate an example in which the opening drive unit 6 moves a pair of target segments 4, 4 around the axis G to an open position located radially outward from the closed position. The opening drive unit 6 is movable along the axial direction of the tread molding unit 3. Note that FIGS. 7, 8, and 11 show cross-sectional views of the demolding mechanism. The cross sections shown in FIGS. 7, 8, and 11 overlap with the axis G and the center of a certain segment 4 in the circumferential direction.

[0049] The opening drive unit 6 has a main body 60 and guide plate units 65, 65 (an example of a segment side cam unit) that engage with the main body 60 while fixed to the segment 4 and move the segment 4 to the open position by upward movement of the main body 60 along the axial direction.

[0050] The main body 60 has a beam portion 61 extending along the radial direction (horizontal direction) and hanging portions 62, 62 extending downward from both ends of the beam portion 61.

[0051] The hanging portion 62 is a member that hangs the guide plate portion 65 and moves the guide plate portion 65 outward.

[0052] As shown in Figures 7, 8, and 10, the radially inner portion of the hanging portion 62 faces inward and is formed with an inner inclined portion 63 having an inclined surface that is linearly inclined with respect to the axial direction so that the upper end side is located more inward than the lower end side. A guide groove 64 (an example of a first rail portion) is formed in the inner inclined portion 63 and extends linearly in the up-down direction from the lower end to the upper end. That is, the guide groove 64 is inclined with respect to the axial direction so that the upper end side is located more inward in the radial direction than the lower end side. The guide groove 64 may have a so-called T-slot (dovetail) shape, for example, in which the circumferential width of the opening of the upper surface of the groove (the inner portion of the groove in the radial direction) is smaller than the circumferential width of the bottom portion of the groove (the outer portion of the groove in the radial direction).

[0053] The guide plate portion 65 is a plate-like member for pulling the segment 4 outward to move it to the open position. The guide plate portion 65 is fixed to the fixing groove 45 with connectors such as pins or bolts, with its plate surface aligned in the radial direction. The guide plate portion 65 is detachable from the segment 4. With its radially inner end fixed to the fixing groove 45 of the segment 4, the guide plate portion 65 engages its radially outer end with the guide groove 64, and moves the main body 60 upward in the axial direction to move the segment 4 to the open position.

[0054] The guide plate portion 65 has its radially outer end engaged with the guide groove 64, and when the main body 60 moves upward in the axial direction, its end is aligned with the guide groove 64 of the inner inclined portion 63 and is pushed outward, thereby moving the segment 4 to the open position.

[0055] At the radially outer end of the guide plate portion 65, a rail portion 66 (an example of a second rail portion) having a T-shaped cross section when viewed along the axial direction (a shape in which the circumferential width of the radially outer portion is wider than the circumferential width of the radially inner portion) may be formed as an engaging portion that engages with the guide groove 64.

[0056] The rail portion 66 is inclined with respect to the axial direction so that the upper end side is positioned radially inward relative to the lower end side. In this embodiment, the rail portion 66 of the guide plate portion 65 fits into the guide groove 64 (see, for example, FIG. 10), so that the guide plate portion 65 is allowed to slide along the inner inclined portion 63 while being pulled outward (see FIGS. 8 and 11).

[0057] In this way, the opening drive unit 6 has the hanging unit 62 and the guide plate unit 65 as a cam mechanism that moves the segments 4 to the open position by movement of the main body 60 along the axial direction.

[0058] The flow of operation of the mold 100 will be described below.

[0059] 3 to 5 show the operation of the molding mechanism. As shown in Fig. 3, first, with each segment 4 positioned in the open position, a tire 200 before molding (before vulcanization) is placed in the mold 100 (lower unit). Then, the lower unit is placed in a state where it overlaps with the upper container 2 and the closing drive unit 7 in the axial direction. At this time, the lower unit is positioned below the upper container 2 and the closing drive unit 7 in the axial direction.

[0060] Thereafter, when the closing drive unit 7 is lowered from the release position to the holding position, the inner inclined surface 74 comes into contact with the outer surface 44, as shown in Figure 4, and urges the outer surface 44 inward. This moves the segment 4 to the closed position. The tire 200 is molded by moving the segment 4 to the closed position.

[0061] After the tire 200 has been vulcanized and molded, the closing drive unit 7 is raised to the release position as shown in Fig. 5. Thereafter, if necessary, the lower unit may be moved to a position where it does not axially overlap with the upper container 2 and the closing drive unit 7. Immediately after the closing drive unit 7 is raised from the holding position to the release position (immediately after molding), each segment 4 remains in the closed position as shown in Figs. 5 and 6. Note that Fig. 6 shows a top view of the lower unit immediately after molding.

[0062] 7 to 11 show the operation of the demolding mechanism. As shown in Fig. 7, after the tire 200 has been vulcanized and molded, the opening drive unit 6 is positioned above the lower unit in the axial direction and overlaps with the lower unit in the axial direction. At this time, it is preferable that the guide plate unit 65 is fitted into the rail unit 66.

[0063] The opening drive unit 6 is lowered from the state shown in FIG. 7 to a state in which the guide plate units 65, 65 are fitted into the fixing grooves 45, 45 of a pair of segments 4, 4 that are symmetrical about the axis G, as shown in FIG. 8. In this state, the guide plate units 65, 65 are fixed to the fixing grooves 45, 45 of the segments 4, 4 with connectors such as pins or bolts. FIG. 9 shows a top view (top view) of the demolding mechanism in this state. The opening drive unit 6 is engaged with a pair of segments 4, 4 (two segments 4 that are part of the eight segments 4) that are symmetrical about the axis G. FIG. 10 is a cross-sectional view taken along the X-X arrows in FIG. 8. As shown in FIG. 10, the inner end of the guide plate unit 65 is fitted into and fixed to the fixing groove 45, and the rail unit 66, which is the outer end of the guide plate unit 65, is fitted into and engaged with the guide groove 64.

[0064] 11, when the main body 60 of the opening drive unit 6 is raised, the guide plate portion 65 fixed to the segment 4 is pulled outward while its rail portion 66 slides downward and radially outward relative to the guide groove 64. Since the segment 4 is prohibited from moving axially by the engagement of the guided portion 49 with the guide groove 14, when the segment 4 moves to the open position, the segment 4 slides on the upper surface of the plate portion 10 and does not move away from the plate portion 10. Note that "the segment 4 slides on the upper surface of the plate portion 10 and does not move away from the plate portion 10" simply means that at least a part of the segment 4 is in contact with the upper surface of the plate portion 10, and does not exclude, for example, the case where the segment 4 is inclined radially inward or outward.

[0065] When raising the main body 60 of the opening drive unit 6, the lower unit may be fixed to a floor surface or a pedestal to prevent the lower unit from rising as the main body 60 rises, but this is usually not necessary. As in this embodiment, the force required to release the tight contact between the surfaces (surfaces facing the tread) of the mold parts 40 of some (e.g., two) of the multiple segments 4 (e.g., eight) and the tread (tread surface) of the tire 200 is sufficiently smaller than the force required to simultaneously release the tight contact between the surfaces of the mold parts 40 of all segments 4 and the tread of the tire 200. Therefore, the upward tractive force applied by the opening drive unit 6 to the lower unit when releasing the tight contact between the surfaces of the mold parts 40 of some of the multiple segments 4 and the tread of the tire 200 is sufficiently smaller than the mass (weight) of the lower unit. Therefore, even if the lower unit is not fixed to the floor or a base, the lower unit does not normally rise due to its own weight as the main body 60 rises, and some of the multiple segments 4 can be moved to the open position by the opening drive unit 6. In other words, the lower unit does not rise due to its own weight.

[0066] Figure 12 shows a top view of the lower unit (tread molding section 3) at an intermediate stage of mold opening, where only two of the eight segments 4 have moved to the open position and the rest remain in the closed position.

[0067] By repeating the operation of moving the two segments 4 to the open position as described above, all of the segments 4 are moved to the open position, as shown in Figure 13, and mold opening of the lower unit (tread molding section 3) is completed. That is, in the demolding mechanism of the mold 100 (see Figure 1) according to this embodiment, the timing at which each segment 4 is opened can be staggered with a simple structure such as the opening drive section 6. Furthermore, in the mold 100, by staggering the timing at which each segment 4 is opened, the maximum value of the tractive force (driving force) required to pull the main body 60 upward when opening the tread molding section 3 (when releasing the tight contact between the surface of the mold section 40 of the segment 4 and the tread of the tire 200) can be made smaller than when each segment 4 is opened simultaneously.

[0068] When all of the segments 4 are moved to the open position and the mold opening of the tread molding section 3 is completed, the molded (vulcanized) tire 200 can be removed from the lower unit.

[0069] In addition, when moving the segment 4 from the state shown in Figure 8 to the open position as shown in Figure 11, the movement speed of the segment 4 to the open position relative to the rising speed of the main body 60 of the opening drive unit 6 can be adjusted by changing the structure of the cam mechanism, i.e., the shape of the hanging part 62 and the guide plate part 65.

[0070] Fig. 14 shows a case where the inclination angle θ of the guide groove 64 and the rail portion 66 that runs along the guide groove 64 with respect to the axial direction is angle θ1. Fig. 15 shows a case where the inclination angle θ of the guide groove 64 and the rail portion 66 that runs along the guide groove 64 with respect to the axial direction is angle θ2. For example, if the angle θ2 (see Fig. 15) is smaller than the angle θ1 (see Fig. 14), the speed at which the segments 4 move to the open position relative to the rising speed of the main body 60 when the inclination angle θ of the rail portion 66 with respect to the axial direction is angle θ2 will be slower than when the inclination angle θ of the rail portion 66 with respect to the axial direction is angle θ1.

[0071] That is, by increasing or decreasing the inclination angle θ, it is possible to increase or decrease the speed at which the segment 4 moves to the open position relative to the rising speed of the main body 60. In other words, by increasing or decreasing the inclination angle θ, it is possible to increase or decrease the traction force (hereinafter referred to as demolding force) that pulls the main body 60 upward, which is required to release the adhesion between the surface of the mold section 40 of the segment 4 and the tread of the tire 200. In this embodiment, the guide plate section 65 is freely attachable to the segment 4, and any shape of the main body 60 (hanging section 62) can be used, so the required demolding force can be easily adjusted.

[0072] For example, by setting the inclination angle θ so that the demolding force does not exceed the mass (weight) of the lower unit, it is possible to avoid the lower unit from rising when releasing the adhesion between the surface of the mold section 40 of the segment 4 and the tread of the tire 200.

[0073] (Variation) In the above embodiment, the opening drive unit 6 engages with the main body 60 while being fixed to the main body 60 and the segments 4, and has guide plate units 65, 65 that move the segments 4 to the open position by upward movement along the axial direction of the main body 60. The main body 60 has a beam unit 61 extending along the radial direction (horizontal direction) and hanging units 62, 62 extending downward from both ends of the beam unit 61, and the hanging unit 62 hangs the guide plate unit 65, and the opening drive unit 6 moves two of the eight (plural) segments 4 to the open position by moving the guide plate unit 65 outward by upward movement along the axial direction of the main body 60.

[0074] However, the number of segments 4 moved in one upward movement along the axial direction of the main body 60 is not limited to two. The number of segments 4 moved in one upward movement along the axial direction of the main body 60 may be less than the total number of segments 4, and may be, for example, one or three. If the total number of segments 4 is eight, the number of segments 4 moved in one upward movement along the axial direction of the main body 60 may be seven or less.

[0075] When the number of segments 4 moved in one upward movement along the axial direction of the main body 60 is three, for example, as shown in Fig. 16, the main body 60 can have branch portions 611, 612, 613 that are arranged at equal intervals along the circumferential direction and extend along the radial direction, instead of the beam portion 61 (see Fig. 9, etc.). Hanging portions 62 (see Fig. 1, etc.) may be provided at the outer ends of the branch portions 611, 612, 613, respectively.

[0076] In this way, it is possible to provide a tire mold having a simple structure that allows the timing at which each segment opens to be staggered.

[0077] It should be noted that the embodiments disclosed in this specification are merely examples, and the embodiments of the present disclosure are not limited to these, and can be modified as appropriate within the scope of the purpose of the present disclosure. [Industrial Applicability]

[0078] The present disclosure is applicable to tire molds and tire demolding devices. [Explanation of symbols]

[0079] 1: Lower container 10: Board part 100: Mold (tire mold) 11: Lower sidewall molding part 14: Guide groove 2: Upper container 20: Board part 200: Tire 21: Upper sidewall molding part 3: Tread molding section 4: Segment 40: Mold section 41: Holder 42: Container 44:Outer surface 45: Fixing groove 49: Information department 6: Open drive unit 60: Main unit 61:Beam part 611: Branch 612: Branch 613: Branch 62: Hanging part 63: Inner slope 64: Guide groove 65: Guide board section 66: Rail section 7: Closing drive unit 74: Inner inclined surface C: Direction G: Axis L: Direction R1: Direction R2: Direction U: Direction θ: Inclination angle θ1: Angle θ2: Angle

Claims

1. an annular tread molding portion divided into a plurality of segments arranged in a circumferential direction; a closing drive unit disposed radially outside the tread molding unit and configured to move the segments to a closed position; an open drive unit that moves some of the plurality of segments to an open position that is located radially outward from the closed position, The opening drive unit is The tread molding portion is movable along the axial direction thereof, a cam mechanism for moving said segments to said open position upon movement along said axial direction;

2. 2. The tire mold according to claim 1, wherein the closing drive unit is movable along the axial direction between a holding position that holds the segment in the closed position and a release position that allows the segment to move to the open position.

3. The axial direction is along the vertical direction, The tire mold according to claim 2 , wherein the opening drive unit moves upward in the vertical direction to move the segments to the open position.

4. The opening drive unit includes the cam mechanism: a segment side cam portion fixed to the segment; a hanging portion that moves the segment-side cam portion outward in the radial direction, 4. The tire mold according to claim 3, wherein the segment-side cam portion is detachable from the segment.

5. The cam mechanism includes: a first rail portion formed on the hanging portion; a second rail portion formed on the segment-side cam portion and engaging with the first rail portion, the first rail portion and the second rail portion are inclined with respect to the axial direction such that an upper end side is positioned radially inward relative to a lower end side, 5. The tire mold according to claim 4, wherein the second rail portion slides downward and radially outward relative to the first rail portion as the first rail portion rises in association with the rise of the hanging portion, thereby moving the segment to the open position.

6. an annular tread molding portion divided into a plurality of segments arranged in a circumferential direction; an opening drive unit that moves some of the plurality of segments to an open position that is located radially outward of a closed position where a tire is molded, The opening drive unit is The tread molding portion is movable along the axial direction thereof, a tire demolding device including a cam mechanism that moves the segments to the open position by movement along the axial direction.

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