Tire vulcanization apparatus and method

Abstract

The present invention provides a tire vulcanization apparatus and method that suppresses the temperature difference between the upper and lower parts of the vulcanization bladder, thereby reducing variations in the degree of tire vulcanization and further improving the uniformity of the tire. [Solution] During the vulcanization of the green tire G, the portion near the upper end 5a of the bladder 5 held by the upper clamp 6A is set to a horizontal position, and the range between this portion and the upper end 5a, and the angle D1 of the upper end 5a with respect to the horizontal are set to 0° to 30° towards the upper center. The portion near the lower end 5b of the bladder 5 held by the lower clamp 6B is set to a horizontal position, and the range between this portion and the lower end 5b, and the angle D2 of the lower end 5b with respect to the horizontal are set to 10° to 30° towards the lower center, and the value of angle D1 is set to be less than or equal to the value of angle D2. The inner surface of the portion near the lower end 5b is set to the uppermost inner surface 5X on the lower side of the bladder 5, and the drain W is passed over the uppermost inner surface 5X which is below the height of the discharge port 4b and discharged from the discharge port 4b.

Description

Technical Field

[0001] The present invention relates to a tire vulcanizing apparatus and method, and more particularly to a tire vulcanizing apparatus and method capable of suppressing the vertical temperature difference of a vulcanizing bladder, reducing the variation in the degree of vulcanization of a tire, and further improving the uniformity of the manufactured tire.

Background Art

[0002] A method for manufacturing a tire is widely used in which a vulcanizing bladder is inserted into a green tire disposed horizontally inside a tire mold, and steam (heating medium) and nitrogen gas (pressurizing medium) are injected into the vulcanizing bladder in a state where the tire mold is closed to vulcanize the green tire. In such a vulcanizing method using steam and nitrogen gas, since the specific gravity of nitrogen gas is larger than that of steam, inside the expanded vulcanizing bladder, steam exists in a compressed state upward and nitrogen gas exists downward. Further, a part of the steam condenses to become drain and accumulates in the lower side inside the vulcanizing bladder, and the temperature of the lower side of the vulcanizing bladder is lowered by this drain. Therefore, in the vulcanizing bladder during vulcanization, the temperature of the upper side becomes higher than that of the lower side, resulting in a vertical temperature difference. Due to this, there is a problem that the degree of vulcanization varies in the vertical direction when the manufactured tire is vulcanized.

[0003] Various proposals have been made to solve these problems (see, for example, Patent Document 1). Patent Document 1 proposes lowering the lower clamp ring and injecting the internal pressure medium from the medium supply port formed in the lower clamp ring at a smaller injection angle near the equatorial plane of the vulcanizing bladder (see Figure 3, etc.). This is expected to heat the vulcanizing bladder uniformly and rapidly from top to bottom, thereby suppressing the amount of drain. However, this method does not guarantee that the amount of drain will be reliably suppressed. Furthermore, the upper end of the vulcanizing bladder described in Patent Document 1 is held by the upper clamp ring in a substantially horizontal state during the vulcanization of the green tire, but the lower end is held by the lower clamp ring in a folded state facing downward. Therefore, with this vulcanizing bladder, it is difficult to stretch it evenly and symmetrically from top to bottom and press it against the green tire even when expanded. As a result, it is disadvantageous for improving the uniformity of the manufactured tire. Therefore, there is room for improvement in suppressing the temperature difference between the top and bottom of the vulcanizing bladder to reduce variations in the degree of tire vulcanization and to improve the uniformity of the manufactured tire. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 56-28844 [Overview of the project] [Problems that the invention aims to solve]

[0005] The object of the present invention is to provide a tire vulcanization apparatus and method that can suppress the temperature difference between the upper and lower parts of the vulcanization bladder, thereby reducing variations in the degree of vulcanization of the tire, and further improving the uniformity of the manufactured tire. [Means for solving the problem]

[0006] To achieve the above objective, the tire vulcanizing apparatus of the present invention comprises a cylindrical vulcanizing bladder, a center post through which the vulcanizing bladder is inserted vertically, an upper clamp and a lower clamp supported by the center post and holding the upper and lower ends of the vulcanizing bladder, respectively, and an injection port and an outlet located inside the vulcanizing bladder, wherein a vulcanizing medium is injected into the vulcanizing bladder from the injection port, a green tire placed horizontally inside a closed tire mold is vulcanized by the vulcanizing bladder expanding inside the green tire, and drain generated inside the vulcanizing bladder during the vulcanization of the green tire is discharged to the outside of the vulcanizing bladder from the outlet, wherein during the vulcanization of the green tire, the portion near the upper end of the vulcanizing bladder held by the upper clamp is in a horizontal state, and The range between the vicinity portion and the upper end and the angle of the upper end with respect to the horizontal are set to 0° or more and 30° or less upward toward the center post, the vicinity portion of the lower end of the vulcanizing bladder held by the lower clamp is in a horizontal state, the range between this vicinity portion and the lower end and the angle of the lower end with respect to the horizontal are set to 10° or more and 30° or less downward toward the center post, the range between the vicinity portion of the upper end and the upper end in a horizontal state and the angle of the upper end with respect to the horizontal are set to be less than or equal to the range between the vicinity portion of the lower end and the lower end in a horizontal state and the angle of the lower end with respect to the horizontal, the inner surface of the vicinity portion of the lower end in a horizontal state is the uppermost inner surface at the highest position on the lower side of the vulcanizing bladder, and the height of this uppermost inner surface is set to be less than or equal to the height of the discharge port.

[0007] The present invention provides a tire vulcanization method in which a center post is inserted vertically through a cylindrical vulcanizing bladder, an upper clamp and a lower clamp that hold the upper and lower ends of the vulcanizing bladder are supported on the center post, an injection port and an outlet are arranged inside the vulcanizing bladder, a vulcanizing medium is injected into the vulcanizing bladder from the injection port, a green tire placed horizontally inside a closed tire mold is vulcanized by the vulcanizing bladder expanding inside the green tire, and drain generated inside the vulcanizing bladder during the vulcanization of the green tire is discharged to the outside of the vulcanizing bladder from the outlet, wherein during the vulcanization of the green tire, the portion near the upper end of the vulcanizing bladder held by the upper clamp is made horizontal, and the range between this portion and the upper end and the angle of the upper end with respect to the horizontal are The following features are characterized by setting the angle upward toward the center post to 0° or more and 30° or less, making the portion near the lower end of the vulcanizing bladder held by the lower clamp horizontal, setting the range between this portion and the lower end and the angle of the lower end with respect to the horizontal to 10° or more and 30° or less downward toward the center post, setting the range between the portion near the upper end in a horizontal state and the upper end and the angle of the upper end with respect to the horizontal to be less than or equal to the range between the portion near the lower end in a horizontal state and the lower end and the angle of the lower end with respect to the horizontal, setting the inner surface of the portion near the lower end in a horizontal state to the highest inner surface on the underside of the vulcanizing bladder, and setting the height of this upper inner surface to be less than or equal to the height of the discharge port, thereby allowing the drain accumulated on the underside of the vulcanizing bladder to pass over the upper inner surface and be discharged from the discharge port. [Effects of the Invention]

[0008] According to the present invention, during the vulcanization of the green tire, the area from the upper end of the vulcanizing bladder held by the upper clamp to its vicinity is nearly horizontal (angle with respect to the horizontal is 0° to 30°), and the area from the lower end of the vulcanizing bladder held by the lower clamp to its vicinity is also nearly horizontal (angle with respect to the horizontal is 10° to 30°). Therefore, the inflated vulcanizing bladder is stretched evenly and generally symmetrically, making it easier to press the green tire. As a result, it is advantageous to further improve the uniformity of the manufactured tire.

[0009] Furthermore, the inner surface near the lower end in a horizontal position is the highest point on the lower side of the vulcanizing bladder, and the height of this upper inner surface is set to be lower than or equal to the height of the discharge port. This allows the drain accumulated on the lower side of the vulcanizing bladder to pass over the upper inner surface and be smoothly discharged from the discharge port. In addition, both the area from the upper end of the vulcanizing bladder held by the upper clamp to its vicinity, and the area from the lower end of the vulcanizing bladder held by the lower clamp to its vicinity, are kept in a nearly horizontal position, while the latter is inclined downwards towards the center post at an angle of 10° or more. This is advantageous for securely holding the lower end with the lower clamp while lowering the height position of the area near the lower end in a horizontal position (the upper inner surface) and the height position of the lower clamp. As a result, the amount of drain accumulated on the lower side of the vulcanizing bladder can be reduced, which is advantageous for suppressing the temperature difference between the upper and lower parts of the vulcanizing bladder and reducing variations in the degree of tire vulcanization. [Brief explanation of the drawing]

[0010] [Figure 1] This is an explanatory diagram illustrating a vertical cross-sectional view of the left half of an embodiment of a tire vulcanization apparatus in which a vulcanizing medium is injected into the inside of a vulcanizing bladder. [Figure 2] This is an explanatory diagram illustrating a tire vulcanization apparatus used to vulcanize the green tire shown in Figure 1. [Figure 3] Figure 2 is an explanatory diagram illustrating a plan view of the lower interior of a tire vulcanizing apparatus. [Figure 4] This is an explanatory diagram illustrating a magnified view of the area around the lower end of the vulcanizing bladder in Figure 2. [Figure 5] Figure 2 is an explanatory diagram illustrating a magnified view of the area around the upper end of the vulcanizing bladder. [Figure 6] Figure 2 is an explanatory diagram illustrating the state in which drain has accumulated inside the vulcanizing bladder. [Figure 7] Figure 6 is an explanatory diagram illustrating, in a plan view, the state in which the drain is discharged from the outlet. [Figure 8] This is an explanatory diagram illustrating the left half of another embodiment of a tire vulcanizing apparatus in a longitudinal cross-sectional view. [Modes for carrying out the invention]

[0011] The tire vulcanization apparatus and method of the present invention will be described below based on the embodiments shown in the figures.

[0012] The embodiment of the tire vulcanizing apparatus 1 (hereinafter referred to as vulcanizing apparatus 1) illustrated in Figures 1 to 5 comprises a cylindrical vulcanizing bladder 5 (hereinafter referred to as bladder 5), a center post 3a through which the bladder 5 is inserted vertically, an upper clamp portion 6c and a lower clamp portion 6c supported by the center post 3a and holding the upper end 5a and lower end 5b of the bladder 5 respectively, an injection port 4a and an outlet port 4b. The central mechanism 3, which includes the center post 3a, is equipped with a disc-shaped upper clamp portion 6c and a lower clamp portion 6c spaced vertically apart on the center post 3a. A vulcanizing mold 7 (hereinafter referred to as mold 7) is installed surrounding the central mechanism 3, and the vulcanizing apparatus 1 further includes opening and closing means (up and down moving plate portion 2 and contailing 15, which will be described later) for opening and closing the mold 7.

[0013] The center post 3a has an inlet 4a and an outlet 4b formed between the upper and lower clamp portions 6c. The inlet 4a and outlet 4b communicate with the injection passage 4c and the discharge passage 4d, respectively, which extend downward from the center post 3a. A heating medium such as steam and a pressurizing medium such as nitrogen gas (hereinafter collectively referred to as the vulcanizing medium M) are injected into the bladder 5 from the inlet 4a through the injection passage 4c. The vulcanizing medium M inside the bladder 5 is discharged to the outside of the bladder 5 from the outlet 4b through the discharge passage 4d. Note that the inlet 4a and outlet 4b can also be located at other positions inside the bladder 5.

[0014] The bladder 5 has a cylindrical body between an annular upper end 5a and an annular lower end 5b. The upper end 5a and the lower end 5b are formed to be thicker than the body. The inner diameters of the upper end 5a and the lower end 5b are set to be substantially the same.

[0015] The upper end portion 5a is held using the upper clamp portion 6c, and the lower end portion 5b is held using the lower clamp portion 6c. More specifically, the upper end portion 5a is held between two upper clamp portions 6c stacked vertically. These two upper clamp portions 6c constitute the upper clamp 6A. The lower end portion 5b is held between one lower clamp portion 6c stacked vertically and the lower bead ring 6d. This lower clamp portion 6c and the lower bead ring 6d constitute the lower clamp 6B.

[0016] The mold 7 is of a sectional type and has an annular upper side mold 7A, an annular lower side mold 7B, and multiple arc-shaped sector molds 7C in plan view. The upper side mold 7A is attached to the lower surface of the upper plate 8. The upper plate 8 and the upper side mold 7A move up and down independently of the vertically moving plate section 2 and the contelling 15.

[0017] The lower side mold 7B is fixedly attached to the upper surface of the lower plate 9 fixed to the base. Each sector mold 7C is attached to the inner peripheral surface of the corresponding segment 10.

[0018] An upper bead ring 6d is attached to the lower surface on the inner peripheral side of the upper side mold 7A. The upper bead ring 6d abuts on the vicinity of the upper end portion 5a. A lower bead ring 6d is attached to the upper surface on the inner peripheral side of the lower side mold 7B. The lower bead ring 6d abuts on the vicinity of the lower end portion 5b.

[0019] Each sector mold 7C (segment 10) is annularly arranged around the central mechanism 3. That is, each sector mold 7C (segment 10) is arranged in an annular shape in a plan view, and the annular center thereof is indicated by a dashed-dotted line CL. The central mechanism 3 (center post 3a) is arranged at the annular center CL. This annular center CL is the annular center of the upper side mold 7A and the lower side mold 7B. Although the left half of the vulcanizing device 1 is shown in FIGS. 1 and 2, the right half has substantially the same structure as the left half.

[0020] The outer peripheral surface of each segment 10 is inclined outwardly from top to bottom. Each segment 10 has a guide groove extending in the vertical direction along the outer peripheral inclined surface.

[0021] A cylindrical container ring 15 is installed on the lower surface of the vertically moving plate portion 2 that moves up and down above the central mechanism 3. The center of the container ring 11 is set around the central mechanism 3 (annular center CL) and moves up and down on the outer peripheral side of each segment 10. The inner peripheral surface of the container ring 11 is inclined outwardly from top to bottom. The inner peripheral inclined surface of the container ring 11 and the outer peripheral inclined surface of each segment 10 are arranged to face each other.

[0022] Multiple guide keys are arranged at circumferential intervals on the inner circumferential inclined surface of the container ring 11. These guide keys extend vertically along the inner circumferential inclined surface of the container ring 11. Each guide key engages with a guide groove of the corresponding segment 10, and the guide key (inner circumferential inclined surface of the container ring 11) and the guide groove (outer circumferential inclined surface of each segment 10) slide against each other.

[0023] Next, we will explain an example of the procedure for manufacturing a tire by vulcanizing a green tire G using this vulcanizing apparatus 1.

[0024] When vulcanizing the green tire G, the mold 7 is opened wide, and the green tire G is placed horizontally on the lower side mold 7B. The lower bead portion Gb of the green tire G is placed on the lower bead ring 6d. The bladder 5 is slightly expanded to hold the green tire G in place.

[0025] Next, the upper side mold 7A is moved downward along with the upper plate 8, which is in an upper standby position, and the container ring 11 and each segment 10 are moved downward along with the vertically moving plate 2. As a result, each segment 10 is placed on the upper surface of the lower plate 9, and each segment 10 is sandwiched between the upper plate 8 and the lower plate 9.

[0026] Next, by moving the container ring 11 further downward together with the vertically moving plate 2, the outer circumferential inclined surface of each segment 10 is pressed against the inner circumferential inclined surface of the downwardly moving container ring 11. As a result, each sector mold 7C moves closer to the annular center CL, and these sector molds 7C are assembled in an annular shape, closing the mold 7.

[0027] Next, as illustrated in Figure 1, a heating medium and a pressurizing medium are sequentially injected into the bladder 5 as the vulcanizing medium M through the injection port 4a. This causes the bladder 5 to expand sufficiently, and the green tire G is pressed against the inner surface of the mold 7 and vulcanized, as illustrated in Figures 2 to 5. Once the predetermined vulcanization time has elapsed and vulcanization is complete, the tire (pneumatic tire) is manufactured.

[0028] As illustrated in Figure 4, during the vulcanization of the green tire G, the portion near the lower end 5b of the bladder 5, which is held by the lower clamp 6B, is in a horizontal state. This portion is the horizontal length H. To maintain good durability of the bladder 5, it is preferable that this horizontal length H be 10 mm or more, for example, 10 mm to 20 mm. The position of one end of this portion coincides with the position of the end of the bead portion Gb of the green tire G. The range between this portion (the horizontal length H portion) and the lower end 5b, and the lower end 5b itself, are continuous extensions, but the angle D2 between them with respect to the horizontal is set to 10° to 30° downward toward the center pole 3a. Furthermore, to maintain good durability of the bladder 5, it is preferable that the range between this portion and the lower end 5b, and the connection portion to this portion, be formed in an arc shape, and the size of the arc (the size of the arc on the outer surface of the bladder 5) be 5 mm or more (5 mm to 10 mm).

[0029] As illustrated in Figure 5, during the vulcanization of the green tire G, the area near the upper end 5a of the bladder 5, which is held by the upper clamp 6A, is in a horizontal state. This area is the portion with a horizontal length H. To maintain good durability of the bladder 5, it is preferable that this horizontal length H be 10 mm or more, for example, 10 mm to 20 mm. The position of one end of this area coincides with the position of the end of the bead portion Gb of the green tire G. The area between this area (the portion with a horizontal length H) and the upper end 5a, and the upper end 5a itself, are continuous extensions, but the angle D1 between them with respect to the horizontal is set to 0° to 30° upwards toward the center pole 3a. In this embodiment, since the angle D1 is set to 0°, the area between the area near the upper end 5a and the upper end 5a, and the upper end 5a itself, extend horizontally in the same way as this area. Note that in Figure 5, the case where the angle D1 is greater than 0° is hypothetically shown with a dashed line. When the angle D1 is greater than 0°, it is preferable for the area between this vicinity and the upper end 5a, and the connection between this vicinity and the upper end 5a, to be formed in an arc shape in order to maintain good durability of the bladder 5. The size of the arc (the size of the arc on the outer surface of the bladder 5) should be 5 mm or more (5 mm to 10 mm).

[0030] Here, the value of angle D1 is set to be less than or equal to the value of angle D2. That is, when comparing the portion from the upper end 5a to its vicinity (the portion with horizontal length H) with the portion from the lower end 5 to its vicinity (the portion with horizontal length H), the degree of horizontality of both is the same, or the portion from the upper end 5a to its vicinity (the portion with horizontal length H) is closer to horizontal.

[0031] Furthermore, the inner surface of the portion near the lower end 5b (i.e., the portion with horizontal length H) is the highest point on the lower inner surface of the bladder 5, which is the uppermost inner surface 5X. The lower side of the bladder 5 refers to the area of ​​the bladder 5 that contacts the lower side portion of the green tire G in a horizontally positioned state, extending from the bead portion Gb. The height of this uppermost inner surface 5X is set to be lower than or equal to the height of the discharge port 4b. More specifically, the height of this uppermost inner surface 5X is the same as, or lower than, the lowest point of the discharge port 4b.

[0032] In this embodiment, the upper surface of the lower clamp portion 6c has a convex portion 6e and a concave portion 6f, and as illustrated in Figure 3, the convex portion 6e and the concave portion 6f are alternately arranged in the circumferential direction around the center CL of the central mechanism 3 (center post 3a). Since the discharge port 4b is formed at the same height as the concave portion 6f, the height of the uppermost part 5X on the inner surface is the same as, or lower than, the height of the concave portion 6f.

[0033] As illustrated in Figure 6, during the vulcanization of the green tire G, some of the injected heating medium, steam, condenses and accumulates as drain W at the bottom of the bladder 5. In this embodiment, the height of the highest point on the lower inner surface of the bladder 5, the uppermost inner surface 5X, is set to be less than or equal to the height of the discharge port 4b. Therefore, the drain W accumulated at the bottom of the bladder 5 flows over the uppermost inner surface 5X towards the discharge port 4b, as illustrated in Figures 6 and 7, and can then be discharged to the outside of the bladder 5 via the discharge passage 4d. In other words, the uppermost inner surface 5X does not obstruct the flow of the drain W accumulated at the bottom of the bladder 5 towards the discharge port 4b, allowing the drain W to flow smoothly towards the discharge port 4b.

[0034] Furthermore, both the area from the upper end 5a of the bladder 5 to its vicinity and the area from the lower end 5b of the bladder 5 to its vicinity are kept nearly horizontal, while the latter is tilted downwards by 10° or more toward the center post 3a. This is advantageous for securely holding the lower end 5b with the lower clamp 6B while lowering the height position of the vicinity of the lower end 5b (uppermost part of the inner surface 5X) and the height position of the upper surface of the lower clamp portion 6c (height position of the recess 6f). As a result, the amount of drain W accumulating on the underside of the bladder 5 can be reduced, thereby suppressing the temperature difference between the upper and lower parts of the bladder 5 and enabling the vulcanization of the green tire 5. In other words, it is advantageous for reducing variations in the degree of vulcanization of the manufactured tires.

[0035] Furthermore, during the vulcanization of the green tire G, the area from the upper end 5a of the bladder 5 held by the upper clamp 6A to its vicinity is nearly horizontal (angle D1 with respect to the horizontal is between 0° and 30°), and the area from the lower end 5b of the bladder 5 held by the lower clamp 6B to its vicinity is also nearly horizontal (angle D2 with respect to the horizontal is between 10° and 30°). Therefore, the inflated bladder 5 is stretched evenly and symmetrically from top to bottom, making it easier to press against the green tire G. As a result, this is advantageous for further improving the uniformity of the manufactured tire.

[0036] When the angle D2 is less than 10°, it is difficult to lower the height position of the area near the lower end 5b (uppermost part of the inner surface 5X) and the height position of the upper surface of the lower clamp portion 6c (height position of the recess 6f) while ensuring sufficient thickness of the lower clamp portion 6c to securely hold the lower end 5b. When the angle D2 is greater than 30°, it becomes difficult to make the expanded bladder 5 stretched evenly and symmetrically from top to bottom, and it is disadvantageous to maintain good durability of the bladder 5.

[0037] To maintain good durability of the bladder 5, it is preferable to keep angles D1 and D2 close to 0°. The upper end 5a side of the bladder 5, unlike the lower end 5b side, is not directly related to problems caused by the drain W. Therefore, it is also possible to set angle D1 to 0° and angle D2 to 10° or more and 30° or less. That is, as illustrated in Figure 6, it is also possible to use a bladder 5 that is not symmetrical with respect to the height center Hz of the bladder 5.

[0038] On the other hand, in order for the inflated bladder 5 to press against the green tire G while being stretched evenly and symmetrically from top to bottom, it is preferable to use a bladder 5 like the embodiment of the vulcanizing apparatus 1 shown in Figure 8. This bladder 5 has a symmetrical shape with respect to the height center Hz of the bladder 5. That is, in this bladder 5, the value of angle D1 and the value of angle D2 are set to the same value.

[0039] Generally, the bladder 5 is manufactured in a cylindrical shape, and is used by being mounted on the central mechanism 3. Instead of manufacturing and using such a cylindrical bladder 5, it is also possible to use a bladder 5 in which the area around the upper end 5a and lower end 5b is pre-formed into the shapes exemplified in Figures 2 and 6. That is, the area near the upper end 5a during vulcanization of the green tire G as exemplified in Figures 2 and 6, the area between this area and the upper end 5a, the area near the upper end 5a and the lower end 5b, the area between this area and the lower end 5b, and the lower end 5b can all be manufactured in the same form (a specification having predetermined angles D1, D2 and horizontal length H).

[0040] The bladder 5, manufactured according to the specifications described above, is attached to the central mechanism 3 for use. In this way, pre-molding and forming the aforementioned part of the bladder 5 to the same shape as the shape when the green tire G is vulcanized is advantageous in ensuring that the green tire G is reliably formed to that shape during vulcanization.

[0041] This vulcanizing apparatus 1 may also be equipped with injection nozzles, agitators, etc., that have the function of stirring the vulcanizing medium M inside the bladder 5. Various known types of injection nozzles, agitators, etc. can be used. [Explanation of Symbols]

[0042] 1. Vulcanizing apparatus 2. Vertically movable plate section 3 Central mechanism 3a Center Post 4a inlet 4b Outlet 4c injection path 4d discharge channel 5. Bladder for vulcanization 5a Upper end 5b Lower end 5X Lower inner top 6A Upper clamp 6B Lower clamp 6c clamp section 6d beading 6e convex part 6f recess 7. Vulcanizing mold 7A Upper side mold 7B Lower side mold 7C Sector Mold 8. Top plate 9. Lower plate 10 segments 11 Container Rings G Green Tire Gb bead section M. Vulcanization medium (heating medium, pressurizing medium) W Drain

Claims

1. A tire vulcanizing apparatus comprising a cylindrical vulcanizing bladder, a center post through which the vulcanizing bladder is inserted vertically, an upper clamp and a lower clamp supported by the center post and holding the upper and lower ends of the vulcanizing bladder, respectively, and an injection port and an outlet located inside the vulcanizing bladder, wherein a vulcanizing medium is injected into the vulcanizing bladder from the injection port, and a green tire, which is placed horizontally inside a closed tire mold, is vulcanized by the vulcanizing bladder expanding inside the green tire, and drain generated inside the vulcanizing bladder during the vulcanization of the green tire is discharged to the outside of the vulcanizing bladder from the outlet, During the vulcanization of the green tire, the portion near the upper end of the vulcanizing bladder held by the upper clamp is in a horizontal state, and the range between this portion and the upper end, and the angle of the upper end with respect to the horizontal, are set to be between 0° and 30° upward toward the center post; the portion near the lower end of the vulcanizing bladder held by the lower clamp is in a horizontal state, and the range between this portion and the lower end, and the angle of the lower end with respect to the horizontal, are set to be between 10° and 30° downward toward the center post; and the range between the portion near the upper end and the upper end in a horizontal state, and the angle of the upper end with respect to the horizontal, are set to be less than or equal to the range between the portion near the lower end and the lower end in a horizontal state, and the angle of the lower end with respect to the horizontal. A tire vulcanizing apparatus in which the inner surface of the portion near the lower end in a horizontal position is the highest inner surface at the lower side of the vulcanizing bladder, and the height of this upper inner surface is set to be less than or equal to the height of the discharge port.

2. The tire vulcanizing apparatus according to claim 1, wherein the length of the portion near the upper end in a horizontal position and the length of the portion near the lower end in a horizontal position are 10 mm or more.

3. The tire vulcanizing apparatus according to claim 1 or 2, wherein the range between the vicinity of the upper end in a horizontal state and the upper end, and the angle of the upper end with respect to the horizontal, and the range between the vicinity of the lower end in a horizontal state and the lower end, and the angle of the lower end with respect to the horizontal are set to be the same.

4. A tire vulcanization method comprising: inserting a center post vertically through a cylindrical vulcanizing bladder; supporting an upper clamp and a lower clamp that hold the upper and lower ends of the vulcanizing bladder, respectively, on the center post; arranging an injection port and an outlet inside the vulcanizing bladder; injecting a vulcanizing medium into the vulcanizing bladder from the injection port; vulcanizing a green tire, which is positioned horizontally inside a closed tire mold, by the vulcanizing bladder expanding inside the green tire; and discharging the drain generated inside the vulcanizing bladder during the vulcanization of the green tire to the outside of the vulcanizing bladder from the outlet, During the vulcanization of the green tire, the portion near the upper end of the vulcanizing bladder held by the upper clamp is made horizontal, and the range between this portion and the upper end, and the angle of the upper end with respect to the horizontal are set to 0° or more and 30° or less upward toward the center post; the portion near the lower end of the vulcanizing bladder held by the lower clamp is made horizontal, and the range between this portion and the lower end, and the angle of the lower end with respect to the horizontal are set to 10° or more and 30° or less downward toward the center post; and the range between the portion near the upper end and the upper end in a horizontal state, and the angle of the upper end with respect to the horizontal are set to be less than or equal to the range between the portion near the lower end and the lower end in a horizontal state, and the angle of the lower end with respect to the horizontal. A method for vulcanizing a tire, wherein the inner surface of the portion near the lower end in a horizontal position is made the highest inner surface at the bottom of the vulcanizing bladder, the uppermost part of the inner surface, and the height of this uppermost part of the inner surface is set to be less than or equal to the height of the discharge port, and the drain accumulated at the bottom of the vulcanizing bladder is discharged from the discharge port by passing over the uppermost part of the inner surface.

5. The method for vulcanizing a tire according to claim 4, wherein the vulcanizing bladder is manufactured to have the same shape as the portion near the upper end of the green tire during vulcanization, the area between this portion and the upper end, the upper end, the portion near the lower end, the area between this portion and the lower end, and the lower end.

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