Tire molding die

Abstract

To provide a tire molding die that is configured to easily find an event even when a vent plug component comes out of an exhaust hole.SOLUTION: There is provided a tire molding die, comprising: a tire forming surface; an exhaust hole that opens at the tire forming surface; and a vent plug that is fitted into the exhaust hole, wherein the vent plug includes: a locking member that can be locked to a second member that remains in the exhaust hole in the vent plug or a step formed in the exhaust hole when a first member constituting at least a part of the vent plug completely comes out of the exhaust hole; and a connecting member that connects the first member and the locking member.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to tire molding tools. [Background technology]

[0002] A tire molding die is provided with many exhaust holes on the tire forming surface that forms the outer surface of the tire. The exhaust holes allow air to escape between the tire outer surface and the tire forming surface during vulcanization molding, through the inside and outside of the die, thereby preventing the formation of dents called bares. During vulcanization molding, rubber on the outer surface of the tire flows into the exhaust holes. As a result, many rubber protrusions called spews are formed on the outer surface of the vulcanized tire. In response to this, a method is known for suppressing the formation of spews by fitting vent plugs into the exhaust holes.

[0003] A known vent plug is a spring vent that includes a substantially cylindrical housing, a stem that is accommodated in the housing and has a valve body on the tire forming surface side, and a spring that biases the stem toward the tire forming surface side (for example, Patent Document 1). This spring vent opens when the spring biases the stem toward the tire forming surface side, allowing air to be discharged. During vulcanization molding, the tire surface presses the stem to close the spring vent, preventing rubber from flowing into the exhaust hole.

[0004] The spring vent stem disclosed in Patent Document 1 has two retaining parts that prevent it from coming off the housing. As a result, even if one retaining part becomes worn or damaged due to vibrations caused by ultrasonic cleaning or long-term use, the other retaining part can prevent the stem from coming off.

[0005] However, if the two retaining parts become worn or damaged, there is a risk that the stem will fall out of the housing (exhaust hole). There is also a risk that the housing will fall out of the exhaust hole. If the stem or housing becomes stuck to the tire and comes out, it may fall out of the tire and fall into the tire molding die, surrounding equipment, or the tire transport path.

[0006] The stems and housings are black and very small, so they are difficult to find after they fall out. Therefore, if the fallen stems or housings fall onto the tire forming surface and are overlooked, there is a risk that the fallen stems or housings will get mixed into the tire during vulcanization molding. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2017-47658 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present disclosure is to provide a tire molding die that makes it easy to detect a component of a vent plug even if it has fallen out of an exhaust hole. [Means for solving the problem]

[0009] The tire molding mold disclosed herein comprises a tire forming surface, an vent hole opening on the tire forming surface, and a vent plug fitted into the vent hole, the vent plug comprising: a locking member capable of locking with a second member of the vent plug remaining in the vent hole or a step formed in the vent hole when a first member constituting at least a part of the vent plug has completely come out of the vent hole; and a connecting member connecting the first member and the locking member. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view showing a tire molding die according to a first embodiment. [Diagram 2] Enlarged view of area II in Figure 1 showing the vent plug [Diagram 3] FIG. 4 is a cross-sectional view corresponding to FIG. 2, showing a vent plug of a tire molding die according to a second embodiment. [Figure 4] FIG. 11 is a cross-sectional view corresponding to FIG. 2 and showing a vent plug of a tire molding die according to a third embodiment. [Diagram 5] FIG. 11 is a cross-sectional view corresponding to FIG. 2 and showing a vent plug of a tire molding die according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (First embodiment) First, an example of the configuration of a tire molding die 100 according to the first embodiment will be described with reference to Fig. 1. Note that in each figure (as well as Figs. 2 to 5), 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.

[0012] Fig. 1 shows a schematic cross section of a tire molding die 100 (hereinafter, may be simply referred to as "die 100") along a tire meridian cross section. The die 100 shown in Fig. 1 is in a closed state. A tire T is set with the tire axial direction facing up and down. In Fig. 1, the left direction is the outer side in the tire radial direction, and the right direction is the inner side in the tire radial direction.

[0013] The mold 100 includes a cavity 15 in which the tire T is set, a tire forming surface 1 in contact with the outer surface of the tire T set in the cavity 15, an exhaust hole 6 opening at the tire forming surface 1, and a vent plug 2 fitted into the exhaust hole 6. The exhaust hole 6 connects the inside (cavity 15) of the mold 100 to the outside. During vulcanization molding, air is exhausted between the outer surface of the tire T and the tire forming surface 1 through the exhaust hole 6.

[0014] An aluminum material is exemplified as a material for the tire forming surface 1. This aluminum material is a concept that includes not only pure aluminum-based materials but also aluminum alloys, such as Al-Cu-based, Al-Mg-based, Al-Mg-Si-based, Al-Zn-Mg-based, Al-Mn-based, and Al-Si-based materials.

[0015] The mold 100 includes a tread mold 11 for forming the tread of the tire T, side molds 12, 13 for forming the sidewalls of the tire T, and bead rings 14, 14 into which the bead portions of the tire T are fitted. The tire forming surface 1 includes the inner surface of the tread mold 11 and the inner surfaces of the side molds 12, 13. Although not shown, the inner surface of the tread mold 11 is provided with projections and recesses for forming the tread pattern of the tire T. Although only one exhaust hole 6 opening on the inner surface of the tread mold 11 is depicted in FIG. 1, in reality, a large number of exhaust holes opening on the inner surfaces of the tread mold 11 and the side molds 12, 13 are provided. In addition, although FIG. 1 shows an example in which the exhaust hole 6 extends linearly, the exhaust hole 6 may extend in a curved manner.

[0016] The vent plug 2 is fitted into an exhaust hole 6 opening on the inner surface of the tread mold 11 serving as the tire forming surface 1, but instead of or in addition to this, it is also possible to fit into an exhaust hole opening on the inner surface of the side mold 12 and / or the side mold 13. Also, while Fig. 1 shows a structure in which the mold 100 includes the tread mold 11 and a pair of side molds 12, 13, the present invention is not limited to this, and for example, the mold structure may be one in which the center of the tread mold is divided into two parts, upper and lower.

[0017] Fig. 2 is an enlarged view of region II in Fig. 1. In Fig. 2, the upper direction is the inner side in the tire radial direction, and the lower direction is the outer side in the tire radial direction. Fig. 2 shows an example in which the vent plug 2 is a spring vent, but is not limited to this. The vent plug 2 may be, for example, a cylindrical vent piece.

[0018] As shown in Fig. 2, the vent plug 2 includes a cylindrical housing 3 having an exhaust passage 21 therein, a stem 4 that is inserted into the housing 3 and serves as a valve body for opening and closing the exhaust passage 21, and a biasing member 5 that biases the stem 4 toward the cavity side S1 (the inner side in the tire radial direction in Fig. 2). The housing 3 and the stem 4 are preferably made of steel such as stainless steel or S45C, and may be made of the same metal or different metals. For convenience of illustration, the stem 4, biasing member 5, and a locking member 7 and a connecting member 8 described below are drawn as viewed from the front.

[0019] The housing 3 is fitted (press-fitted) into the vent hole 6 by an interference fit. The housing 3 has an annular top surface 31 facing the cavity 15, a tapered surface 32 that reduces in diameter from the top surface 31 toward the anti-cavity side S2 (the tire radial outside in FIG. 2), and a cylindrical surface 33 that extends from the tapered surface 32 toward the anti-cavity side S2 along the axial direction AD of the housing 3 (vent plug 2). The axial direction AD coincides with the central axial direction of the stem 4 and the central axial direction of the vent hole 6. The top surface 31 is disposed, for example, flush with (i.e., on the same plane as) the tire forming surface 1.

[0020] The end of the housing 3 on the side S2 opposite the cavity is provided with a through hole 34, an inner flange-shaped support portion 35, and a tapered surface 37 that expands in diameter from a bottom surface 36 of the housing 3 toward the cavity side S1. The bottom surface 36 is the end surface of the housing 3 on the side S2 opposite the cavity.

[0021] The housing 3 has a slit 38. The slit 38 extends along the axial direction AD from the bottom surface 36 to a position beyond the support portion 35. The gap between the cylindrical surface 33 and the stem 4 and the exhaust hole 6 are communicated by the slit 38. The width W1 of the slit 38 is smaller than the inner diameter D1 of the support portion 35. The inner diameter D1 of the support portion 35 is equal to the outer diameter of the through hole 34. In this embodiment, the housing 3 has a pair of slits 38 (one of them is not shown).

[0022] The stem 4 includes a columnar body 41 and a head 42 integrally connected to the body 41. The body 41 is formed in a cylindrical shape extending in the axial direction AD. A gap through which air can pass is formed between the body 41 and the cylindrical surface 33 surrounding it. A biasing member 5 is disposed in the gap.

[0023] A retaining portion 43 having a diameter larger than that of the through hole 34 is provided at the end of the body 41 on the side S2 opposite the cavity. The retaining portion 43 acts to prevent the stem 4 from coming out of the housing 3.

[0024] The head 42 is formed in a truncated cone shape that tapers toward the anti-cavity side S2. The head 42 has a tapered side surface that corresponds to the tapered surface 32. A gap through which air can pass is formed between the head 42 and the tapered surface 32 that surrounds it by the action of the biasing member 5.

[0025] The biasing member 5 is interposed between the head 42 and the support portion 35, and biases (pushes up) the stem 4 so as to open the exhaust path 21. The biasing member 5 is, for example, a coil spring.

[0026] In Fig. 2, the biasing member 5 pushes up the stem 4, thereby opening the exhaust passage 21 and the vent plug 2 is in an open state. While the vent plug 2 is in an open state, the air in the cavity 15 is discharged to the outside of the mold 100 through the exhaust passage 21 as the outer surface of the tire approaches the tire forming surface 1. The exhaust passage 21 is formed by the gap between the housing 3 and the stem 4 and the slit 38. More specifically, the exhaust passage 21 is formed so as to pass from the gap between the tapered surface 32 and the head 42, through the gap between the cylindrical surface 33 and the body 41, and through the slit 38.

[0027] It is preferable that a step 61 is formed in the exhaust hole 6. The step 61 increases the diameter of the exhaust hole 6 on the anti-cavity side S2. The step 61 is provided on the anti-cavity side S2 further from the vent plug 2, and on the cavity side S1 further from a locking member 7 described later. The step 61 is provided between the vent plug 2 and the locking member 7.

[0028] The vent plug 2 includes a locking member 7 that can be locked to the second member B or the step 61 when the first member A constituting at least a part of the vent plug 2 is completely removed from the exhaust hole 6, and a connecting member 8 that connects the first member A and the locking member 7. With this configuration, when the first member A is completely removed from the exhaust hole 6 (to the cavity side S1), the locking member 7 connected to the first member A is locked to the second member B or the step 61, and the first member A is likely to be in a hanging state. By the first member A being in a hanging state, the first member A becomes easily noticeable to the worker, and it becomes easy to find the first member A that has fallen out. In addition, even if the first member A falls out of the exhaust hole 6, the locking member 7 and the connecting member 8 make it easy for the worker to find the first member A that has fallen out.

[0029] The state in which the first member A has completely come out of the vent hole 6 means that the end of the first member A on the anti-cavity side S2 protrudes beyond the tire forming surface 1 towards the cavity side S1.

[0030] The first member A is a part or all of the members that constitute the vent plug 2. The first member A is preferably the stem 4. With such a configuration, when the stem 4 becomes worn or damaged due to vibrations caused by ultrasonic cleaning or long-term use and comes out of the housing 3, it becomes easy to find the stem 4 that has come out.

[0031] In this embodiment, the first member A is the stem 4, but is not limited to this. For example, the first member A may be the housing 3, and the locking member 7 may be connected to the housing 3. Alternatively, the first member A may be the housing 3 and the stem 4, and different locking members 7 may be connected to both the housing 3 and the stem 4. When the vent plug 2 is a vent piece, the vent piece main body that is fitted into the exhaust hole 6 becomes the first member A, and the locking member 7 is connected to the vent piece main body.

[0032] In this embodiment, the connecting member 8 is preferably attached to the retaining portion 43. This configuration can prevent contact between the connecting member 8 and the housing 3, and can prevent the connecting member 8 from interfering with the operation of the stem 4. The connecting member 8 is attached to the end face S2 of the retaining portion 43 on the opposite cavity side by welding or brazing, but is not limited to this.

[0033] The second member B is a member of the vent plug 2 that is different from the first member A and is fitted into the exhaust hole 6. The second member B remains in the exhaust hole 6 when the first member A is removed. In this embodiment, the second member B is the housing 3, and the locking member 7 is not connected to the second member B, but this is not limited to this. For example, a locking member may also be connected to the housing 3, which is the second member B.

[0034] The connecting member 8 is a long and thin member extending along the axial direction AD. The connecting member 8 is preferably a flexible member. This allows the connecting member 8 to bend and change the orientation of the locking member 7, making it easier to insert the locking member 7 into the housing 3 when inserting (attaching) the stem 4 into the housing 3. In addition, the bending of the connecting member 8 makes it easier for the locking member 7 to be locked to the second member B or the step 61.

[0035] The connecting member 8 is preferably a wire. With such a configuration, when the first member A comes out, the connecting member 8 bends, and the locking member 7 becomes more likely to lock onto the second member B or the step 61. The connecting member 8 is preferably made of metal (for example, steel or stainless steel). FIG. 2 shows an example in which the connecting member 8 is a wire rope extending linearly, but this is not limited thereto. For example, the connecting member 8 may be a rod-shaped member or a plate-shaped member. The connecting member 8 may also be a member extending in a zigzag shape or a spiral shape along the axial direction AD.

[0036] It is preferable that the connecting member 8 is a color different from that of the first member A. For example, when the stem 4, which is the first member A, is black, it is preferable that the connecting member 8 is a color different from black. With such a configuration, the connecting member 8 is more noticeable to the worker, making it easier to find the first member A that has come out of the exhaust hole 6. The color of the connecting member 8 may be the color of the material of the connecting member 8 (for example, silver), or may be a color that has been colored by painting or the like.

[0037] The outer diameter D2 of the connection member 8 is preferably smaller than the outer diameter of the through hole 34 (the inner diameter D1 of the support portion 35). This allows the connection member 8 to be inserted into the housing 3 when the stem 4 is inserted (attached) into the housing 3. As a result, if the locking member 7 can also be inserted into the housing 3, the stem 4 to which the locking member 7 is connected can be inserted into the housing 3 after the housing 3 is fitted into the exhaust hole 6. If the locking member 7 cannot be inserted into the housing 3, the locking member 7 and the connection member 8 may be inserted into the exhaust hole 6 from the anti-cavity side S2, the connection member 8 may be inserted into the housing 3, and then the connection member 8 may be attached to the stem 4 on the cavity side S1 before the stem 4 is inserted into the housing 3.

[0038] The locking member 7 is formed in a shape that allows it to be locked to the second member B or the step 61. When the locking member 7 is locked to the second member B or the step 61, the first member A connected to the locking member 7 protrudes from the through hole 6 and hangs down, making it easily noticeable to the worker.

[0039] The distance Ds1 in the axial direction AD between the locking member 7 and the end of the first member A on the side S2 opposite to the cavity is greater than the length L1 in the axial direction AD of the second member B (the housing 3 in this embodiment). As a result, when the locking member 7 is completely removed from the exhaust hole 6 to the tire forming surface 1 side (the cavity side S1), the locking member 7 is locked to the second member B, and the first member A is in a state of protruding from the exhaust hole 6 and hanging down. In addition, the contact distance of the locking member 7 with the second member B and the exhaust hole 6 is increased, and the force of the first member A coming out can be weakened. As a result, the locking member 7 is easily locked to the second member, and the first member A is less likely to fall out of the exhaust hole 6. Furthermore, when the first member A is pushed out to the cavity side S1 for replacement, the connection member 8 can be pushed out further to the cavity side S1 than the tire forming surface 1 before the locking member 7 is locked to the second member B. This allows the connection member 8 to be cut on the cavity side S1, eliminating the need to pass the locking member 7 through the second member B and retrieve it from the exhaust hole 6, facilitating replacement of the first member A. When the connection member 8 is cut, the locking member 7 can be retrieved from the anti-cavity side S2.

[0040] In the case where the second member B is not present, such as when the locking member 7 is connected to the housing or the ventlid main body, the distance Ds1 is greater than the distance Ds2 from the tire forming surface 1 to the step 61. When the locking member 7 is to be locked to the step 61, the locking member 7 is preferably disposed on the outer circumferential side relative to the central axis of the vent hole 6, and more preferably disposed in contact with the vent hole 6. This makes it easier to lock the locking member 7 to the step 61.

[0041] The outer diameter D3 (width D3) of the locking member 7 is preferably larger than the inner diameter D1 of the support portion 35. This makes it easier for the locking member 7 to lock to the support portion 35 when the first member A is the stem 4. In this embodiment, the outer diameter D3 (width D3) of the locking member 7 is larger than the inner diameter D4 of the end S2 of the second member B (housing 3) on the side opposite the cavity, but is not limited to this. The outer diameter D3 (width D3) of the locking member 7 is preferably smaller than the inner diameter of the exhaust hole 6. This makes it possible to prevent the locking member 7 from constantly coming into contact with the exhaust hole 6 and to prevent the operation of the stem 4 from being hindered.

[0042] The locking member 7 is preferably formed in a brush shape. That is, the locking member 7 is preferably provided with a plurality of elastically deformable bristles 71. With such a configuration, the locking member 7 is bent, so that, for example, when inserting (attaching) the stem 4 into the housing 3, the locking member 7 can be inserted into the through hole 34 or the slit 38 of the housing 3. This makes it easier to arrange the locking member 7 on the side S2 opposite the cavity from the first member A. In addition, since the first member A comes out of the exhaust hole 6 while the plurality of bristles 71 of the locking member 7 are in contact with the second member B or the step 61, the force of the first member A coming out can be weakened. This makes it easier to lock the bristles 71 of the locking member 7 to the second member B or the step 61.

[0043] The bristles 71 are preferably arranged radially from the axial center of the locking member 7. That is, the locking member 7 is preferably formed into a cylindrical shape by the bristles 71. This makes it easier to lock the locking member 7 to the second member B or the step 61. Note that the bristles 71 may be arranged, for example, in only one direction intersecting with the axial direction AD.

[0044] When the locking member 7 is formed in a brush shape, it is preferable that the length L2 in the axial direction AD of the locking member 7 is greater than the length L1 in the axial direction AD of the housing 3. This increases the length of contact between the multiple bristles 71 of the locking member 7 and the second member B (housing 3) or the exhaust hole 6, and weakens the force with which the first member A (stem 4) comes out. As a result, it becomes easier to lock the bristles 71 of the locking member 7 to the second member B or the step 61.

[0045] It is preferable that the locking member 7 is a color different from that of the first member A. For example, when the stem 4, which is the first member A, is black, it is preferable that the locking member 7 is a color different from black. This makes the locking member 7 more noticeable to the worker, making it easier to find the first member A when it falls out of the exhaust hole 6. The color of the locking member 7 may be the color of the material of the locking member 7 (for example, silver), or may be a color colored by painting or the like. The locking member 7 may be the same color as the connecting member 8, or a color different from that of the connecting member 8.

[0046] Second embodiment Next, a second embodiment of the tire molding die 100 will be described with reference to Fig. 3. Since the second embodiment can be configured similarly to the first embodiment except for the configuration described below, the common features will be omitted and differences will be mainly described. The same reference numerals will be used for the configuration already described in the first embodiment, and duplicated explanations will be omitted. Fig. 3 is a view corresponding to Fig. 2 showing the vent plug 2 of the tire molding die 100 according to the second embodiment. For convenience of explanation, the housing 3 shown in Fig. 3 is rotated 90 degrees relative to the circumferential direction of the exhaust hole 6 from the housing 3 shown in Fig. 2.

[0047] In the second embodiment, the connection member 8 is attached to the body 41 of the stem 4 as shown in FIG. 3. The connection member 8 is a wire. A ring portion 81 is formed on the end of the connection member 8 on the cavity side S1 along a direction intersecting (perpendicular to) the axial direction AD. The ring portion 81 is bent with respect to the axial direction AD. The ring portion 81 is formed after the wire, which is the connection member 8, is wound around the body 41, and the connection member 8 is attached to the stem 4. FIG. 3 shows an example in which the ring portion 81 is provided in the gap of the spring, which is the biasing member 5, but the ring portion 81 may be provided on the end of the biasing member 5 on the anti-cavity side S2.

[0048] The maximum outer diameter D2 of the connecting member 8 (excluding the ring portion 81) is smaller than the width W1 (see FIG. 2) of the slit 38. This allows the connecting member 8 to be disposed within the slit 38, and prevents the operation of the stem 4 from being hindered by attaching the connecting member 8 to the body 41.

[0049] In this embodiment, the locking member 7 is formed in a tag-like shape (a substantially rectangular plate-like shape). The thickness direction of the locking member 7 is a direction intersecting the axial direction AD (a direction perpendicular to the paper surface in FIG. 3). The locking member 7 is preferably shaped so that it can be inserted through the slit 38 or through-hole 34 when inserting (attaching) the stem 4 into the housing 3. This allows the stem 4 connected to the locking member 7 to be inserted into the housing 3 after the housing 3 is fitted into the exhaust hole 6. The locking member 7 may be formed in a circular or rectangular shape in a cross section perpendicular to the axial direction AD.

[0050] Third embodiment Next, a third embodiment of the tire molding die 100 will be described with reference to Fig. 4. Since the third embodiment can be configured similarly to the second embodiment except for the configuration described below, the common points will be omitted and differences will be mainly described. The same reference numerals will be used to designate components already described in the second embodiment, and duplicated explanations will be omitted. Fig. 4 is a view corresponding to Fig. 2 and showing the vent plug 2 of the tire molding die 100 according to the third embodiment.

[0051] 4, the stem 4 has a through hole 44 for attaching the connection member 8. The through hole 44 is preferably provided in the retaining portion 43. This can prevent the connection member 8 from coming into contact with the housing 3, and can prevent the operation of the stem 4 from being hindered by the connection member 8.

[0052] The connection member 8 is a wire. A loop portion 81 is formed along the axial direction AD on the cavity side S1 of the connection member 8. The loop portion 81 is formed after the wire, which is the connection member 8, is passed through the through hole 44, and the connection member 8 is attached to the stem 4.

[0053] (Fourth embodiment) Next, a fourth embodiment of the tire molding die 100 will be described with reference to Fig. 5. The fourth embodiment can be configured similarly to the first embodiment except for the configuration described below, so commonalities will be omitted and differences will be mainly described. Configurations already described in the first embodiment will be given the same reference numerals and duplicated explanations will be omitted. Fig. 5 is a view corresponding to Fig. 2 and showing the vent plug 2 of the tire molding die 100 according to the fourth embodiment.

[0054] In the fourth embodiment, the connection member 8 is a wire, and the locking member 7 is formed in a spring shape, as shown in Fig. 5. The locking member 7 is formed, for example, by processing a part of the wire that is the connection member 8.

[0055] It is preferable that the gap G1 of the locking member 7 is larger than the length L3 in the axial direction AD of the support portion 35. This makes it easier to rotate the locking member 7 by fitting the support portion 35 into the gap G1 of the locking member 7. As a result, the locking member 7 can be rotated and passed through the support portion 35, making it easier to insert the locking member 7 into the housing 3.

[0056] [1] As described above, the tire molding mold 100 disclosed herein comprises a tire forming surface 1, an vent hole 6 opening at the tire forming surface 1, and a vent plug 2 fitted into the vent hole 6, and the vent plug 2 comprises a locking member 7 that can lock with a second member B of the vent plug 2 that remains in the vent hole 6 or a step 61 formed in the vent hole 6 when a first member A constituting at least a part of the vent plug 2 has completely come out of the vent hole 6, and a connecting member 8 that connects the first member A and the locking member 7.

[0057] According to this configuration, when the first member A completely comes out of the exhaust hole 6, the locking member 7 connected to the first member A is locked to the second member B or the step 61, and the first member A is likely to be in a hanging state. As a result, the first member A is in a hanging state, making it easier for the worker to notice the first member A and to find the pulled-out first member A.

[0058] [2] In the tire molding die 100 of [1] above, the vent plug 2 may be configured to include a cylindrical housing 3 having an exhaust passage 21 therein that communicates with the exhaust hole 6, and a stem 4 that is inserted into the housing 3 and serves as a valve body that opens and closes the exhaust passage 21, and the first member A may be the stem 4.

[0059] According to such a configuration, when the stem 4 becomes worn or damaged due to vibrations caused by ultrasonic cleaning or long-term use and falls out of the housing 3, the fallen out stem 4 can be easily found.

[0060] [3] In the tire molding mold 100 of [2] above, the stem 4 may be provided with a removal prevention portion 43 that prevents the stem 4 from coming out of the housing 3, the removal prevention portion 43 being provided at the end of the stem 4 opposite the tire forming surface 1 (the anti-cavity side S2), and the connecting member 8 may be attached to the removal prevention portion 43.

[0061] According to such a configuration, contact between the connection member 8 and the housing 3 can be suppressed, and the operation of the stem 4 can be prevented from being hindered by the connection member 8.

[0062] [4] In the tire molding die 100 of any one of the above items [1] to [3], the connection member 8 is preferably a wire.

[0063] According to such a configuration, when the first member A is pulled out, the connecting member 8 is bent, and the locking member 7 can be easily locked to the second member B or the step 61.

[0064] [5] In the tire molding mold 100 of any one of the above [1] to [4], the connection member 8 is preferably configured to have a color different from that of the first member A.

[0065] According to such a configuration, the connection member 8 is easily noticeable to an operator, and the first member A that has come out from the exhaust hole 6 can be easily found.

[0066] [6] In the tire molding die 100 of any one of the above items [1] to [5], the locking member 7 is preferably formed in a brush shape.

[0067] According to this configuration, by bending the locking member 7, for example, when inserting (attaching) the stem 4 into the housing 3, the locking member 7 can be inserted into the through hole 34 or the slit 38 of the housing 3. This makes it easier to arrange the locking member 7 on the side S2 opposite the cavity relative to the first member A. Also, since the first member A comes out of the exhaust hole 6 while the multiple bristles 71 of the locking member 7 come into contact with the second member B or the step 61, the force with which the first member A comes out can be weakened. This makes it easier to lock the locking member 7 to the second member B or the step 61.

[0068] The tire molding die 100 is not limited to the configurations of the above-described embodiments, and is not limited to the above-described effects. Needless to say, various modifications can be made to the tire molding die 100 without departing from the spirit of the present invention. For example, it is possible to arbitrarily select one or more of the configurations, methods, etc. according to the above-described first to fourth embodiments and adopt them in the configurations, methods, etc. according to the other embodiments. [Explanation of symbols]

[0069] 1... tire forming surface, 2... vent plug, 21... exhaust passage, 3... housing, 31... top surface, 32... tapered surface, 33... cylindrical surface, 34... through hole, 35... support portion, 36... bottom surface, 37... tapered surface, 38... slit, 4... stem, 41... body, 42... head, 43... retention portion, 44... through hole, 5... biasing member, 6... exhaust hole, 61... step, 7... locking member, 71... bristles, 8... connecting member, 81... ring portion, 11... tread mold, 12... side mold, 13... side mold, 14... bead ring, 15... cavity, 100... tire molding die, T... tire

Claims

1. A tire forming surface; An exhaust hole opening on the tire forming surface; A vent plug is fitted into the exhaust hole, The vent plug is a locking member that can be locked to a second member of the vent plug that remains in the exhaust hole or a step formed in the exhaust hole when a first member constituting at least a part of the vent plug is completely removed from the exhaust hole; a connecting member that connects the first member and the locking member.

2. the vent plug comprises a cylindrical housing having an exhaust passage therein that communicates with the exhaust hole, and a stem that is inserted into the housing and serves as a valve body that opens and closes the exhaust passage, The tire mold according to claim 1 , wherein the first member is the stem.

3. The stem includes a retaining portion that prevents the stem from coming out of the housing, The retaining portion is provided on an end portion of the stem opposite to the tire forming surface, The tire molding die according to claim 2 , wherein the connecting member is attached to the retaining portion.

4. The tire mold according to claim 1 , wherein the connecting member is a wire.

5. The tire mold of claim 1 , wherein the connecting member has a different color than the first member.

6. The tire molding mold according to any one of claims 1 to 5, wherein the locking member is formed in a brush shape.

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