Tire vulcanizing device

Abstract

To provide a tire vulcanizing device capable of suppressing breakage of a bolt that fixes an engagement pin.SOLUTION: There is provided a tire vulcanizing device, comprising a segment that holds a sector for forming a tread surface, and a container ring that is provided on an outer side in a tire radial direction of the segment. The tire vulcanizing device is configured in that: a groove extending in an up-down direction is provided on the outer side of the segment in the tire radial direction; the container ring includes an engagement pin that engages with the groove when a mold is opened, and a fitting hole into which the engagement pin is fitted; the engagement pin is fixed to the fitting hole with a bolt; a pin-side step that expands in diameter at a position spaced apart in an axial direction of the engagement pin from an outer end in the tire radial direction of the engagement pin is provided at least in a lower portion of the outer peripheral surface of the engagement pin; and the fitting hole is provided with a hole-side step corresponding to the pin-side step.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a tire vulcanizing apparatus. [Background technology]

[0002] A tire vulcanizing apparatus for vulcanizing unvulcanized tires includes segments with sectors attached to their inner peripheries and a container ring placed on the outer periphery of the segments (see, for example, Patent Document 1). Tapered surfaces with the same inclination are formed on the outer periphery of the segments and the inner periphery of the container ring that slides against them. These tapered surfaces are each inclined downward and outward in the tire radial direction. This allows the sectors to move freely in the tire radial direction as the container ring is raised and lowered.

[0003] The outer periphery of each segment is provided with a groove extending in the vertical direction, and the container ring is provided with a cylindrical engagement pin that engages with the groove when the mold is opened. By engaging the engagement pin with the groove, the sectors and segments are lifted when the container ring is raised. At that time, the load of the segments, including the sectors, is applied to the engagement pin.

[0004] When the tire curing mold is repeatedly opened and closed, as shown in FIG. 8(a), the load F9 of the segments including the sector gradually deforms the engagement pin 932, and as shown in FIG. 8(b), a gap G9 is generated between the engagement pin 932 and the fitting hole 933. When the tire curing mold is further repeatedly opened and closed, the load F9 gradually tilts the engagement pin 932 within the fitting hole 933, and as shown in FIG. 8(c), stress concentrates on a part of the bolt B9 (circled part X9 in FIG. 8(c)) that secures the engagement pin 932. When stress concentrates on a part of the bolt B9, there is a risk that the bolt B9 will break and the engagement pin 932 will fall out of the fitting hole 933. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-27633 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present disclosure is to provide a tire vulcanizing apparatus that can suppress breakage of bolts that secure engagement pins. [Means for solving the problem]

[0007] The tire vulcanizing apparatus of the present disclosure comprises segments that hold sectors for forming a tread surface, and a container ring provided on the radially outer side of the segment, wherein a groove extending in the vertical direction is provided on the radially outer side of the segment, the container ring comprises an engagement pin that engages with the groove when the mold is opened, and an insertion hole into which the engagement pin is fitted, the engagement pin is fixed to the insertion hole with a bolt, and at least a lower part of the outer peripheral surface of the engagement pin is provided with a pin-side step that expands in diameter at a position spaced apart from the radially outer end of the engagement pin in the axial direction of the engagement pin, and the insertion hole is provided with a hole-side step that corresponds to the pin-side step. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram schematically illustrating a cross section along a tire meridian cross section of a tire vulcanizing apparatus according to one embodiment. [Figure 2] A cross-sectional view corresponding to Figure 1 showing the sector in an expanded diameter state. [Figure 3] A cross-sectional view corresponding to Figure 1 showing the sector in the raised position. [Figure 4] Enlarged cross-sectional view of the engagement pin of Figure 1 [Figure 5] A diagram showing the state in which a load of a segment including a sector is applied to an engagement pin. [Figure 6] FIG. 10 is an enlarged cross-sectional view of an engagement pin of a tire vulcanizing apparatus according to another embodiment. [Figure 7] FIG. 10 is an enlarged cross-sectional view of an engagement pin of a tire vulcanizing apparatus according to another embodiment. [Figure 8] FIG. 10 is a diagram showing a state in which a load of a segment including a sector is applied to an engagement pin of a conventional example. DETAILED DESCRIPTION OF THE INVENTION

[0009] An example of the configuration of a tire vulcanizing apparatus 100 (hereinafter, may be simply referred to as "vulcanizing apparatus 100") that vulcanizes an unvulcanized tire will be described with reference to Fig. 1. Note that in each figure (similarly to Figs. 2 to 8), the dimensional ratios in the drawing do not necessarily match the actual dimensional ratios, and the dimensional ratios between the drawings do not necessarily match either.

[0010] In each drawing, the first direction D1 is the tire axial direction D1 that is parallel to the tire rotation axis of the pneumatic tire T (hereinafter also simply referred to as "tire T"), and the second direction D2 is the tire radial direction D2 that is the diameter direction of the tire T. The direction around the tire rotation axis is called the tire circumferential direction.

[0011] In the tire radial direction D2, the inner side is the side closer to the tire rotation axis, and the outer side is the side farther from the tire rotation axis. The tire meridian cross section is a cross section that includes the tire rotation axis and is perpendicular to the tire equatorial plane, and the tire equatorial plane is a plane that is perpendicular to the tire rotation axis and is located at the center of the tire T in the tire axial direction D1.

[0012] Fig. 1 is a schematic diagram showing a cross section along the tire meridian cross section of a vulcanizing apparatus 100. The vulcanizing apparatus 100 is equipped with a tire vulcanizing mold 1 (hereinafter, may be simply referred to as "vulcanizing mold 1"). In Fig. 1, the vulcanizing mold 1 is in a mold-closed state, and a tire T (unvulcanized tire) is set with the tire axial direction D1 facing up and down.

[0013] The vulcanization mold 1 includes a tread mold 11 that forms the tread of the tire T, an upper side mold 12 and a lower side mold 13 that form the sidewalls of the tire T, and bead rings 14 and 15 into which the bead portions of the tire T are fitted.

[0014] The tread mold 11 is made up of a plurality of sectors 11a divided in the tire circumferential direction, and these sectors are gathered together to form a ring when the mold is closed. The vulcanization mold 1 according to this embodiment is a segmented mold equipped with such a divided type tread mold 11.

[0015] The vulcanization mold 1 has a tire molding surface 16 that comes into contact with the outer surface of the set tire T. The tire molding surface 16 includes the inner surface of the tread mold 11 and the inner surfaces of the side molds 12 and 13. Although not shown in the figure, the inner surface of the tread mold 11 has projections and recesses for forming the tread pattern of the tire T.

[0016] The vulcanization mold 1 is provided with vent holes (not shown) that discharge air that is present between the outer surface of the unvulcanized tire and the tire molding surface 16 during vulcanization molding. The vent holes are also called vent holes and are formed to open into the tire molding surface 16.

[0017] The vulcanizing apparatus 100 is provided with an exhaust line (not shown) that communicates with the vent hole. During vulcanization molding, excess air between the outer surface of the unvulcanized tire and the tire molding surface 16 is discharged from the vent hole to the outside via the exhaust line.

[0018] The vulcanization apparatus 100 includes segments 2 that hold sectors 11a (tread molds 11), and container rings 3 that are provided on the outer side of the segments 2 in the tire radial direction D2. A plurality of segments 2 are provided corresponding to each sector 11a. The outer portion of the segment 2 in the tire radial direction D2 and the inner portion of the container ring 3 in the tire radial direction D2 are inclined downward and outward in the tire radial direction D2. These portions slide as the container ring 3 is raised and lowered, allowing the sectors 11a to move freely in the tire radial direction D2. The segments 2 and the container ring 3 will be described in detail later.

[0019] The vulcanization apparatus 100 includes an upper platen (not shown) that supports the upper side mold 12, a lower platen 4 that supports the lower side mold 13, and an arm (not shown) that supports the container ring 3. The upper platen is configured to be able to move up and down, and the segments 2 are supported on the lower surface of the upper platen so that they can slide along the tire radial direction D2. The arm is attached to a guide (not shown) that is erected on the upper surface of the upper platen so that it can move up and down. As the arm moves up and down relative to the guide, the container ring 3 moves up and down relative to the segments 2.

[0020] The vulcanization device 100 includes a tire vulcanization bladder 5 (hereinafter, sometimes simply referred to as the "bladder 5"), which is a rubber bag body, a central mechanism 6 provided in the center of the vulcanization mold 1, and supply and discharge lines (not shown) that communicate with the inside of the bladder 5.

[0021] Bladder 5 is placed inside an unvulcanized tire (tire T) set in vulcanization mold 1. Bladder 5 expands and deforms when a high-temperature, high-pressure vulcanization medium is supplied from a supply line, and contracts and deforms when the vulcanization medium filled inside is discharged through a discharge line. Bladder 5 is supported by a central mechanism 6. Specifically, an upper end of bladder 5 is supported by an upper clamp 61 of the central mechanism 6, and a lower end of bladder 5 is supported by a lower clamp 62 of the central mechanism 6.

[0022] The vulcanization molding of the tire T is performed in the mold closed state shown in FIG. 1. A heat source Hs such as an electric heater or a steam jacket is provided inside the container ring 3, and by heating the container ring 3, the vulcanization mold 1 is heated through the segments 2. The tire T is heated by the heated vulcanization mold 1 and the high-temperature, high-pressure vulcanization medium, and vulcanization molding is performed. After vulcanization molding is completed, the sector 11a is expanded in diameter (see FIG. 2) and raised, and the mold is opened (see FIG. 3). FIG. 2 is a cross-sectional view corresponding to FIG. 1 showing the state in which the sector 11a is expanded in diameter, and FIG. 3 is a cross-sectional view corresponding to FIG. 1 showing the state in which the sector 11a is raised. Although FIG. 3 shows the state in which only the sector 11a is raised, in reality, the upper side mold 12 and the bead ring 14 are also raised together with the sector 11a when the mold is opened.

[0023] The center mechanism 6 includes a center post 63 extending in the vertical direction (tire axial direction D1) at the center of the vulcanization mold 1. The center post 63 is arranged spaced apart on the inner side in the tire radial direction D2 relative to the vulcanization mold 1. An upper clamp 61 and a lower clamp 62 are attached to the center post 63. At least a portion of each of the upper clamp 61 and the lower clamp 62, together with the bladder 5, is configured to be detachable from the center post 63.

[0024] The segment 2 includes a segment-side tapered surface 21 that slopes downward and outward in the tire radial direction D2, and a sliding member 22 that slides against the container ring 3. The segment-side tapered surface 21 is provided on the outer periphery of the segment 2 (outside in the tire radial direction D2), and the sliding member 22 is provided on the segment-side tapered surface 21. The sliding member 22 extends in the up-down direction.

[0025] Grooves 23 extending in the up-down direction are provided on the outer side of the segment 2 in the tire radial direction D2. In this embodiment, the grooves 23 are provided on the sliding member 22. In the extending direction of the grooves 23, the upper ends of the grooves 23 are closed and the lower ends of the grooves 23 are open.

[0026] The container ring 3 has a container ring side tapered surface 31 (hereinafter, may be simply referred to as "tapered surface 31") that slopes downward and outward in the tire radial direction D2, an engagement pin 32 that engages with the groove 23 (at the upper end) when the mold is opened (when the container ring 3 is raised), and a fitting hole 33 into which the engagement pin 32 is fitted. The engagement pin 32 is fixed in the fitting hole 33 with a bolt B1.

[0027] The tapered surface 31 is inclined in the same direction as the segment-side tapered surface 21. In this embodiment, the tapered surface 31 slides against a sliding member 22 provided on the segment-side tapered surface 21, allowing the sector 11a to move freely in the tire radial direction D2.

[0028] FIG. 4 is an enlarged cross-sectional view of the engagement pin 32 of FIG. 1. As shown in FIG. 4, the engagement pin 32 is fitted into the fitting hole 33, with a portion of it (an engagement portion 322, described later) protruding from the tapered surface 31. In this embodiment, the engagement pin 32 is fitted into the fitting hole 33 along the central axis CL1 of the engagement pin 32 up to the bottom surface 33a of the fitting hole 33. The central axis CL1 of the engagement pin 32 in the fitted state and the central axis of the fitting hole 33 substantially coincide with each other. The engagement pin 32 is preferably formed in a substantially cylindrical shape. This allows the engagement pin 32 to engage with the groove 23 more smoothly than when the engagement pin 32 is formed in a rectangular parallelepiped shape or the like. This is because if the engagement pin 32 has an edged shape, such as a rectangular parallelepiped shape, there is a risk of interference between the edge and the groove 23. The engagement pin 32 is not limited to the above shape and may be formed in a rectangular parallelepiped, elliptical cylindrical, semi-cylindrical, or other shape.

[0029] The fitting hole 33 is provided on the lower side of the container ring 3 and opens at the tapered surface 31. The fitting hole 33 is a hole that extends from the tapered surface 31 along the tire radial direction D2. In this embodiment, the fitting hole 33 is a hole that extends along a direction perpendicular to the tapered surface 31. The fitting hole 33 is formed in a shape that allows the engagement pin 32 to be fitted therein. The fitting hole 33 is preferably formed in a substantially cylindrical shape.

[0030] At least a lower portion of the outer peripheral surface of the engagement pin 32 is provided with a first pin-side step 321 (hereinafter, may be simply referred to as a "pin-side step 321") that expands in diameter at a position spaced apart from an outer end 32a of the engagement pin 32 in the tire radial direction D2 in the axial (central axis CL1) direction of the engagement pin 32. The fitting hole 33 is provided with a hole-side step 331 that corresponds to the pin-side step 321. That is, at least a lower portion of the side wall surface of the fitting hole 33 is provided with the hole-side step 331 that expands in diameter at a position spaced apart from a bottom surface 33a of the fitting hole 33 in the axial direction of the fitting hole 33. With this configuration, when the upper part of the engagement pin 32 engages with the groove 23 and a load of the segment 2 including the sector downward (hereinafter, sometimes simply referred to as the "load of the segment 2") is applied, the pin-side step 321 provided on the lower part of the engagement pin 32 comes into contact with the hole-side step 331 provided on the fitting hole 33, preventing the engagement pin 32 from tilting within the fitting hole 33. This prevents stress from concentrating on a part of the bolt B1, preventing the bolt B1 from breaking. Furthermore, because the bolt B1 is less likely to break than in the conventional example, it becomes easier for a maintenance technician to discover that the engagement pin 32 is tilted within the fitting hole 33 before the bolt B1 breaks.

[0031] Specifically, when the vulcanization mold is repeatedly opened and closed, as shown in FIG. 5( a), the load F1 of the segment 2 gradually deforms the engagement pin 32, and as shown in FIG. 5( b), a gap G1 is generated between the engagement pin 32 and the fitting hole 33. At this time, the load F1 of the segment 2 generates a rotational force (moment) around the lower part of the engagement pin 32 (near the opening of the fitting hole 33) as a fulcrum. However, the pin-side step 321 comes into contact with the hole-side step 331, thereby mitigating the contact between the upper part of the engagement pin 32 (circled area Y in FIG. 5( b)) and the fitting hole 33 caused by the rotational force. This suppresses deformation of the upper part of the engagement pin 32 due to the load F1 of the segment 2. Furthermore, as shown in FIG. 5( c), even after the gap G1 is generated between the engagement pin 32 and the fitting hole 33, the pin-side step 321 continues to come into contact with the hole-side step 331, thereby suppressing tilting of the engagement pin 32 within the fitting hole 33. These prevent stress from concentrating on a part of the bolt B1 that secures the engagement pin 32 (the circled part X1 in FIG. 5(c)), and prevent the bolt B1 from breaking.

[0032] The pin-side step 321 (face) faces outward in the tire radial direction D2. The hole-side step 331 (face) faces inward in the tire radial direction D2 (toward the segment 2). It is preferable that the outer end 32a of the engagement pin 32 contacts the bottom surface 33a of the fitting hole 33.

[0033] The pin-side step 321 is preferably provided around the entire circumference of (the outer circumferential surface of) the engagement pin 32. The hole-side step 331 is preferably provided around the entire circumference of (the side wall surface of) the fitting hole 33. With this configuration, the contact area between the pin-side step 321 and the hole-side step 331 increases, further preventing the engagement pin 32 from tilting inside the fitting hole 33 due to the load of the segment 2. Furthermore, providing the steps 321, 331 around the entire circumference makes it easier to process the steps 321, 331.

[0034] 4, the length L1 from the outer end 32a of the engagement pin 32 to the pin-side step 321 is preferably 50% or less of the length L2 of the engagement pin 32 in the direction of the central axis CL1. That is, the pin-side step 321 is preferably provided outward in the tire radial direction D2 from the center of the engagement pin 32 in the direction of the central axis CL1. This makes it possible to prevent a decrease in the strength of the engagement pin 32 due to the provision of the pin-side step 321. The length L1 is more preferably 40% or less of the length L2, even more preferably 30% or less of the length L2, and even more preferably 20% or less of the length L2.

[0035] The length L3 from the bottom surface 33a of the fitting hole 33 to the hole-side step 331 is preferably 50% or less of the depth Dp of the fitting hole 33. The length L3 is more preferably 40% or less of the depth Dp, and even more preferably 30% or less of the depth Dp.

[0036] The radial width W1 of the pin-side step 321 of the engagement pin 32 is preferably 1 mm or more. This ensures a contact margin between the pin-side step 321 and the hole-side step 331. The width W1 is more preferably 2 mm or more. The same applies to the width of the hole-side step 331.

[0037] The angle θ1 formed between the pin-side step 321 and the enlarged diameter surface 32b of the engagement pin 32 is preferably 70 degrees or more, more preferably 80 degrees or more, and even more preferably 85 degrees or more. The angle θ1 is preferably 110 degrees or less, more preferably 100 degrees or less, and even more preferably 95 degrees or less. In this embodiment, the angle θ1 is 90 degrees, but is not limited to this. The same applies to the angle formed between the hole-side step 331 and the side wall surface of the fitting hole 33.

[0038] The engagement pin 32 has an engagement portion 322 that engages with (the upper end of) the groove 23. The engagement portion 322 is a portion of the engagement pin 32 that protrudes from the fitting hole 33 (the tapered surface 31). In this embodiment, a second pin-side step 323 is provided around the entire outer circumferential surface of the engagement pin 32. The second pin-side step 323 reduces in diameter between the first pin-side step 321 and the inner end 32c of the engagement pin 32 in the tire radial direction D2. By providing the second pin-side step 323, the outer diameter Dm3 of the engagement portion 322 can be adjusted to match the outer diameter of a conventional engagement pin, allowing the conventional segment 2 to be used as is. The second pin-side step 323 is provided at a position spaced from the first pin-side step 321 toward the inner end 32c of the engagement pin 32 in the axial (center axis CL1) direction. Note that the present invention is not limited to the above, and the engagement pin 32 does not necessarily have to have the second pin-side step 323.

[0039] The second pin-side step 323 is located closer to the segment 2 than the first pin-side step 321, and the engagement portion 322 is located closer to the segment 2 than the second pin-side step 323. The second pin-side step 323 is preferably located so as to be substantially flush with the tapered surface 31, or on the opposite side of the tapered surface 31 from the segment 2 (outside in the tire radial direction D2). This makes it possible to prevent the second pin-side step 323 from coming into contact with the segment 2 (slide member 22) when engaging with the groove 23.

[0040] The length L4 from the inner end 32c of the engagement pin 32 in the tire radial direction D2 to the second pin-side step 323 (the length L4 of the engagement portion 322) is longer than the length L1 from the outer end 32a of the engagement pin 32 to the first pin-side step 321. The length L4 of the engagement portion 322 is, for example, 1.5 times or more and 2.5 times or less the length L1. In this embodiment, the length L4 of the engagement portion 322 is twice the length L1, but is not limited to this.

[0041] The outer diameter Dm1 of the outer end 32a of the engagement pin 32 is smaller than the outer diameter Dm2 of the expanded diameter surface 32b of the engagement pin 32. The outer diameter Dm1 of the outer end 32a is substantially the same as the outer diameter Dm3 of the inner end 32c (engagement portion 322) of the engagement pin 32. The length L2 of the engagement pin 32 is larger than the minimum diameter (outer diameters Dm1, Dm3) of the engagement pin 32. The length L2 of the engagement pin 32 is smaller than the maximum diameter (outer diameter Dm2) of the engagement pin 32.

[0042] The engagement pin 32 is fixed to the fitting hole 33 by a bolt B1. The nominal diameter of the bolt B1 is preferably 50% or more of the minimum diameter (outer diameter Dm1) of the engagement pin 32. This configuration increases the fixing force of the engagement pin 32 to the fitting hole 33, and prevents the bolt B1 from loosening. This prevents stress from concentrating on one part of the bolt B1, and prevents the bolt B1 from breaking due to the load of the segment 2. In this embodiment, the nominal diameter of the bolt B1 is M16, but is not limited to this.

[0043] The threaded portion of bolt B1 is positioned so as to face the segment 2 side. It is preferable that the amount by which the threaded portion of bolt B1 protrudes from tapered surface 31 toward segment 2 is 1 mm or less. This configuration can prevent the bolt B1 from breaking due to the shear force generated when the engagement pin 32 engages with the groove 23. In this embodiment, the threaded portion of bolt B1 does not protrude from tapered surface 31 toward segment 2. That is, the inner end of bolt B1 in the tire radial direction D2 is positioned on the opposite side from segment 2 (outside in the tire radial direction D2) of tapered surface 31.

[0044] The safety factor of bolt B1 against the load of segment 2 is preferably 3 times or more. For example, when the threaded portion of bolt B1 protrudes 1 mm from tapered surface 31 toward segment 2, the weight of segment 2 including the sector is 80 kg to 110 kg, and the safety factor is 25, the nominal diameter required to prevent bolt B1 (material: SCM435) from bending is 4.8 to 5.3 mm. The required nominal diameter is calculated, for example, from bending moment, bending stress, safety factor, and section modulus. In this embodiment, the nominal diameter of bolt B1 is 3 to 3.3 times the required nominal diameter calculated above.

[0045] The engagement pin 32 has a female thread 324 that screws into the bolt B1. The central axis CL2 of the bolt B1 (the central axis of the female thread 324) is preferably offset from the central axis CL1 of the engagement pin 32. This makes it possible to prevent the engagement pin 32 from rotating within the fitting hole 33 when the engagement pin 32 is fixed to the fitting hole 33 with the bolt B1. The central axis CL2 of the bolt B1 (the central axis of the female thread 324) is preferably located above the central axis CL1 of the engagement pin 32. This increases the strength of the lower side of the engagement pin 32 and prevents the pin-side step 321 from being deformed due to contact with the hole-side step 331. In this embodiment, the central axis CL2 of the bolt B1 is substantially parallel to the central axis CL1 of the engagement pin 32.

[0046] The amount Ap of protrusion of the female thread 324 from the tapered surface 31 toward the segment 2 is preferably 1 mm or less. This configuration prevents a decrease in the strength of the engagement pin 32 due to the provision of the female thread 324, and prevents the engagement pin 32 from being deformed or broken when engaging with the groove 23.

[0047] The length of engagement between the female thread 324 and the bolt B1 is preferably 50% or more of the length L2 of the engagement pin 32. This increases the fixing force of the engagement pin 32 to the fitting hole 33, and prevents the bolt B1 from loosening. As a result, stress is prevented from concentrating on one part of the bolt B1, and the bolt B1 is prevented from breaking due to the load of the segment 2.

[0048] The fitting length L5 of the engagement pin 32 into the fitting hole 33 is preferably 50% or more of the length L2 of the engagement pin 32. This configuration increases the fixing force of the engagement pin 32 in the fitting hole 33 and prevents the engagement pin 32 from tilting within the fitting hole 33. This prevents the bolt B1 from breaking due to the load of the segment 2. It is more preferable that the fitting length L5 of the engagement pin 32 be 60% or more of the length L2 of the engagement pin 32.

[0049] The fitting length of the engaging pin 32 (depth Dp of the fitting hole 33) is preferably 20% or more of the thickness T1 of the container ring 3 in the direction of the central axis CL2, and more preferably 30% or more of the thickness T1 of the container ring 3.

[0050] [1] As described above, the tire vulcanizing apparatus 100 according to this embodiment comprises a segment 2 that holds the sector 11a for forming the tread surface, and a container ring 3 provided on the outer side of the segment 2 in the tire radial direction D2, and a groove 23 extending in the vertical direction is provided on the outer side of the segment 2 in the tire radial direction D2, and the container ring 3 comprises an engagement pin 32 that engages with the groove 23 when the mold is opened, and an insertion hole 33 into which the engagement pin 32 is inserted, and the engagement pin 32 is fixed in the insertion hole 33 with a bolt B1, and at least a lower part of the outer peripheral surface of the engagement pin 32 is provided with a pin-side step 321 that expands in diameter at a position spaced from the outer end 32a of the engagement pin 32 in the tire radial direction D2 in the direction of the axis (center axis CL1) of the engagement pin 32, and the insertion hole 33 is provided with a hole-side step 331 corresponding to the pin-side step 321.

[0051] With this configuration, when the upper part of the engagement pin 32 engages with the groove 23 and a load is applied downward from the segment 2 including the sector 11a, the pin-side step 321 provided at the lower part of the engagement pin 32 comes into contact with the hole-side step 331 provided in the fitting hole 33, preventing the engagement pin 32 from tilting within the fitting hole 33. This prevents stress from concentrating on a part of the bolt B1 that secures the engagement pin 32, preventing the bolt B1 from breaking.

[0052] [2] In the tire vulcanizing apparatus 100 according to the above embodiment [1], it is preferable that the pin-side step 321 is provided around the entire circumference of the engaging pin 32.

[0053] This configuration increases the contact area between the pin-side step 321 and the hole-side step 331, further preventing the engagement pin 32 from tilting in the fitting hole 33 due to the load of the segment 2. This prevents stress from concentrating on a part of the bolt B1 that secures the engagement pin 32, and prevents the bolt B1 from breaking.

[0054] [3] In the tire vulcanizing apparatus 100 according to the above embodiment [1] or [2], it is preferable that the nominal diameter of the bolt B1 is 50% or more of the minimum diameter (Dm1) of the engaging pin 32.

[0055] This configuration increases the fixing force of the engagement pin 32 in the fitting hole 33, and prevents the bolt B1 from loosening. This prevents stress from concentrating on a part of the bolt B1, and prevents the bolt B1 from breaking due to the load of the segment 2.

[0056] [4] In the tire vulcanizing apparatus 100 according to any one of the above embodiments [1] to [3], it is preferable that the segment 2 side of the container ring 3 is provided with a tapered surface 31 that slopes downward and outward in the tire radial direction D2, the engagement pin 32 has a female thread 324 that screws into the bolt B1, and the protrusion amount Ap of the female thread 324 from the tapered surface 31 toward the segment 2 side is 1 mm or less.

[0057] According to this configuration, the reduction in strength of the engagement pin 32 caused by providing the female thread 324 is suppressed, and the engagement pin 32 is prevented from being deformed or broken when engaged with the groove 23.

[0058] [5] In the tire vulcanizer 100 according to any one of the above embodiments [1] to [4], it is preferable that the fitting length L5 of the engaging pin 32 into the fitting hole 33 is 50% or more of the length L2 of the engaging pin 32.

[0059] This configuration increases the fixing force of the engagement pin 32 to the fitting hole 33, and further prevents the engagement pin 32 from tilting within the fitting hole 33. This prevents stress from concentrating on a part of the bolt B1 that fixes the engagement pin 32, and prevents the bolt B1 from breaking.

[0060] The tire vulcanizing apparatus 100 is not limited to the configuration of the above-described embodiment, and is not limited to the above-described effects. Furthermore, it goes without saying that various modifications can be made to the tire vulcanizing apparatus 100 without departing from the gist of the present invention. For example, it goes without saying that one or more of the configurations, methods, etc. related to the various modified examples described below may be arbitrarily selected and adopted in the configurations, methods, etc. related to the above-described embodiment.

[0061] (A) In this embodiment, the pin-side step 321 is provided around the entire circumference of the engagement pin 32, but this is not limited to this. For example, as shown in Fig. 6, the pin-side step 321 may be provided only on the lower part of the engagement pin 32. The hole-side step 331 is similar to the pin-side step 321.

[0062] (B) In this embodiment, one pin-side step 321 is provided on the outer periphery of the engagement pin 32, but this is not limiting. For example, as shown in FIG. 7, a configuration may be adopted in which a plurality of pin-side steps 321 are provided on the outer periphery of the engagement pin 32. In such a configuration, the plurality of pin-side steps 321 are provided in a staircase shape. The same applies to the hole-side step 331 as to the pin-side step 321.

[0063] (C) In this embodiment, the groove 23 is provided on the sliding member 22, but this is not limiting. For example, the groove 23 may be provided on the segment-side tapered surface 21. In such a configuration, the sliding member 22 may be provided on the tapered surface 31. [Explanation of symbols]

[0064] 100... tire vulcanization apparatus, 1... tire vulcanization mold, 11... tread mold, 11a... sector, 12... upper side mold, 13... lower side mold, 14... bead ring, 15... bead ring, 16... tire molding surface, 2... segment, 21... segment side tapered surface, 22... sliding member, 23... groove, 3... container ring, 31... container ring side tapered surface, 32... engagement pin, 32a... outer side end, 32b...expansion surface, 32c...inner end, 321...first pin side step, 322...engagement portion, 323...second pin side step, 324...female thread, 33...insertion hole, 33a...bottom surface, 331...hole side step, 4...lower platen, 5...tire vulcanization bladder, 6...center mechanism, 61...upper clamp, 62...lower clamp, 63...center post, B1...bolt, CL1, CL2...center axis, Hs...heat source, T...pneumatic tire

Claims

1. a segment holding a sector for forming a tread surface; a container ring provided on the outer side of the segment in the tire radial direction, A groove extending in the up-down direction is provided on the outer side of the segment in the tire radial direction, the container ring includes an engagement pin that engages with the groove when the mold is opened, and an engagement hole into which the engagement pin is fitted; The engagement pin is fixed to the fitting hole with a bolt, a pin-side step that expands in diameter at a position spaced apart from the outer end of the engagement pin in the axial direction of the engagement pin from the outer end in the tire radial direction of the engagement pin is provided at least in a lower part of the outer peripheral surface of the engagement pin; The tire vulcanizing apparatus, wherein the fitting hole is provided with a hole-side step corresponding to the pin-side step.

2. The tire vulcanizing apparatus according to claim 1 , wherein the pin-side step is provided around the entire circumference of the engagement pin.

3. 2. The tire vulcanizing apparatus according to claim 1, wherein the nominal diameter of the bolt is 50% or more of the minimum diameter of the engagement pin.

4. a tapered surface inclined downward and outward in the tire radial direction is provided on the segment side of the container ring, The engagement pin has a female thread that threadably engages with the bolt, 2. The tire vulcanizing apparatus according to claim 1, wherein the amount of protrusion of the female thread from the tapered surface toward the segment is 1 mm or less.

5. 5. The tire vulcanizing apparatus according to claim 1, wherein the length of the engagement pin inserted into the insertion hole is 50% or more of the length of the engagement pin.

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