Tire post cure inflation method and device

Abstract

To provide a post-cure inflation method and device for more reliably inflating a tire even when a vertical distance between bead parts immediately after vulcanization becomes too small.SOLUTION: There is provided a post-cure inflation method, comprising: holding upper and lower bead portions Tb of a tire T that is laid down and immediately after vulcanization by a pair of upper and lower holding portions 5a and 5b; holding a state in which the holding portions 5a and 5b are in continuous annular contact with the tire T in a circumferential direction by setting a vertical interval between the holding portions 5a and 5b to a holding interval Di during injection, which is smaller than a vertical interval Db between the upper and lower bead portions Tb of the tire T immediately after vulcanization; injecting a cooling medium C into the tire T by an injection portion 6 to inflate the tire T; expanding the vertical interval between the holding portions 5a and 5b from the holding interval Di during injection to a preset reference interval Dc; and maintaining an inflated state of the tire T.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a method and apparatus for post-cure inflation of a tire, and more specifically, to a method and apparatus for post-cure inflation of a tire that can more reliably inflate a tire even when the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization is too small. [Background technology]

[0002] When a tire using organic fiber cords as a reinforcing material is naturally cooled after vulcanization, the organic fiber cords may shrink excessively and deform into an inappropriate tire shape. In order to prevent such a problem, a post-cure inflation process (hereinafter referred to as a PCI process) is performed in which a cooling medium such as air is injected into the tire immediately after vulcanization and the tire is cooled in an inflated state. Various devices for performing this PCI process have been proposed (for example, see Patent Documents 1 and 2).

[0003] In recent years, the weight of tires has been reduced, and as a result, the vertical distance between the upper and lower bead portions of a tire immediately after vulcanization when the tire is laid on its side may be excessively small. In the PCI process, the upper and lower bead portions are held by a pair of upper and lower holding portions to inflate the tire, but if the vertical distance between the upper and lower bead portions is too small, a gap is generated between the upper portion of the tire held by the lower holding portion and the upper holding portion. When inflating the tire, the cooling medium flows out from this gap, and the tire cannot be sufficiently inflated, making it impossible to carry out the PCI process. Therefore, there is room for improvement in order to inflate the tire more reliably, even if the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization is too small. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 1-154714 [Patent Document 2] Japanese Patent Application Publication No. 6-285871 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a method and apparatus for post-cure inflation of a tire that can more reliably inflate a tire even when the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization is too small. [Means for solving the problem]

[0006] In order to achieve the above object, the present invention provides a tire post-cure inflation method, which comprises holding upper and lower bead portions of a tire immediately after vulcanization, laid on its side, with a pair of upper and lower holding portions, and injecting a cooling medium into the tire to maintain the tire in an inflated state, comprising: The tire is placed on its side and held on the lower holding portion, and a vertical gap between the upper holding portion and the surface of the tire facing the holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected vertical gap becomes zero, The vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, and the pair of upper and lower retaining parts are each abutted against the tire in a circumferentially continuous ring shape, and the tire is inflated with the cooling medium, while the vertical distance between the pair of upper and lower retaining parts is expanded from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state. Another tire post-cure inflation method of the present invention is a tire post-cure inflation method in which upper and lower bead portions of a tire immediately after vulcanization that is laid on its side are held by a pair of upper and lower holding portions, and a cooling medium is injected into the inside of the tire to maintain the tire in an inflated state, characterized in that the tire that is laid on its side is placed on the lower holding portion and held thereon, an outflow pressure of the cooling medium flowing from the inside of the tire to the outside through a vertical gap between the upper holding portion and a surface of the tire facing this holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected outflow pressure becomes zero, thereby making the vertical distance between the pair of upper and lower holding portions an injection time holding distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization that is laid on its side, and the pair of upper and lower holding portions are each brought into contact with the tire in a circumferentially continuous ring shape, and the tire is inflated with the cooling medium, while the vertical distance between the pair of upper and lower holding portions is expanded from the injection time holding distance to a preset reference distance to maintain the tire in an inflated state. Another tire post-cure inflation method of the present invention is a tire post-cure inflation method in which upper and lower bead portions of a tire immediately after vulcanization that is laid on its side are held by a pair of upper and lower holding portions, and a cooling medium is injected into the tire to maintain the tire in an inflated state, characterized in that the tire that is laid on its side is placed on the lower holding portion and held thereon, the contact pressure between the upper holding portion and a surface of the tire facing this holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected contact pressure rises to a preset reference value, thereby making the vertical distance between the pair of upper and lower holding portions an injection time holding distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization that is laid on its side, thereby abutting the pair of upper and lower holding portions against the tire in a circumferentially continuous ring shape, and inflating the tire with the cooling medium, while expanding the vertical distance between the pair of upper and lower holding portions from the injection time holding distance to a preset reference distance to maintain the tire in an inflated state. Another tire post-cure inflation method of the present invention is a tire post-cure inflation method in which upper and lower bead portions of a tire immediately after vulcanization that is laid on its side are held by a pair of upper and lower holding portions, and a cooling medium is injected into the interior of the tire to maintain the tire in an inflated state, characterized in that the tire is laid on its side and held on the lower holding portion, and while injecting the cooling medium into the interior of the tire, the internal pressure of the tire is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected internal pressure rises to a preset reference value, thereby making the vertical distance between the pair of upper and lower holding portions an injection time holding distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization that is laid on its side, and the pair of upper and lower holding portions are each brought into contact with the tire in a circumferentially continuous ring shape, and the tire is inflated with the cooling medium, while the vertical distance between the pair of upper and lower holding portions is expanded from the injection time holding distance to a preset reference distance to maintain the tire in an inflated state. Another tire post-cure inflation method of the present invention is a tire post-cure inflation method in which the upper and lower bead portions of a tire immediately after vulcanization and laid on its side are held by a pair of upper and lower holding portions, and a cooling medium is injected into the tire to maintain the tire in an inflated state, characterized in that an actual value of the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization and laid on its side is grasped in advance for each tire specification, the holding distance at injection is set to 80% to 95% of the actual value, and the vertical distance between the pair of upper and lower holding portions is set to the holding distance at injection smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization and laid on its side, thereby abutting the pair of upper and lower holding portions against the tire in a circumferentially continuous ring shape, and inflating the tire with the cooling medium, while expanding the vertical distance between the pair of upper and lower holding portions from the holding distance at injection to a preset standard distance to maintain the tire in an inflated state.

[0007] The tire post-cure inflation device of the present invention comprises a pair of upper and lower holding parts for holding upper and lower bead parts of a tire immediately after vulcanization in a laid-on position, and an injection part for injecting a cooling medium into the tire, and the tire is maintained in an inflated state by the cooling medium, and further comprises a gap reduction mechanism for reducing the vertical gap between the upper and lower bead parts of the tire immediately after vulcanization in a laid-on position, The gap reduction mechanism includes a sensor that detects a vertical gap between the upper holding portion and a surface of the tire that faces the upper holding portion and is placed sideways on the lower holding portion, and reduces the vertical gap between the pair of upper and lower holding portions until the vertical gap detected by the sensor becomes zero, The holding distance at the time of injection is set to be smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when the tire is laid on its side. hand The pair of upper and lower retaining portions are each abutted against the tire in a circumferentially continuous ring shape, and while the tire is inflated with the cooling medium, the upper and lower spacing between the pair of upper and lower retaining portions is expanded from the retention spacing at the time of injection to a preset reference spacing, thereby maintaining the tire in an inflated state. Another tire post-cure inflation device of the present invention is a tire post-cure inflation device that includes a pair of upper and lower holding parts that hold upper and lower bead parts of a tire immediately after vulcanization in a laid-on position, and an injection part that injects a cooling medium into the inside of the tire, and the tire is maintained in an inflated state by the cooling medium. The tire post-cure inflation device has a gap reduction mechanism that reduces the vertical gap between the upper and lower bead parts of the tire immediately after vulcanization in a laid-on position, and the gap reduction mechanism is configured to reduce the vertical gap between the upper and lower holding parts and a surface of the tire that is placed on its side and held on the lower holding part, facing the upper holding part, and is configured to reduce the vertical gap between the upper and lower holding parts and the surface of the tire that is placed on its side and held on the lower holding part, facing the upper holding part. a sensor for detecting the outflow pressure of the cooling medium flowing out to each of the bead portions, and by reducing the vertical distance between the pair of upper and lower holding parts until the outflow pressure detected by the sensor becomes zero, an injection holding distance is set to be smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, and the pair of upper and lower holding parts are each abutted against the tire in a circumferentially continuous annular shape, and while the tire is inflated with the cooling medium, the vertical distance between the pair of upper and lower holding parts is expanded from the injection holding distance to a preset reference distance, thereby maintaining the tire in an inflated state. Another tire post-cure inflation device of the present invention is equipped with a pair of upper and lower holding parts for holding upper and lower bead parts of a tire immediately after vulcanization in a laid-on position, and an injection part for injecting a cooling medium into the inside of the tire, and the tire is maintained in an inflated state by the cooling medium. The tire post-cure inflation device has a gap reduction mechanism for reducing the vertical gap between the upper and lower bead parts of the tire immediately after vulcanization in a laid-on position, and the gap reduction mechanism detects the contact pressure between the upper holding part and a surface facing the upper holding part of the tire placed and held on the lower holding part in a laid-on position. The tire is configured to have a sensor that detects the contact pressure detected by the sensor and reduces the vertical distance between the pair of upper and lower holding parts until the contact pressure detected by the sensor rises to a preset reference value, thereby making the injection holding distance smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, and the pair of upper and lower holding parts are each abutted against the tire in a circumferentially continuous annular shape, and while the tire is inflated by the cooling medium, the vertical distance between the pair of upper and lower holding parts is expanded from the injection holding distance to a preset reference distance, thereby maintaining the tire in an inflated state. Another tire post-cure inflation device of the present invention includes a pair of upper and lower holding sections that hold upper and lower bead sections of a tire immediately after vulcanization in a laid-on position, and an injection section that injects a cooling medium into the tire, and the tire is maintained in an inflated state by the cooling medium. The tire post-cure inflation device further includes a gap reduction mechanism that reduces the vertical gap between the upper and lower bead sections of the tire immediately after vulcanization in a laid-on position, and the gap reduction mechanism detects the internal pressure of the tire in a state in which the cooling medium is injected into the tire placed on its side and held in the lower holding section. The tire is configured to have a sensor that detects the internal pressure of the tire and reduces the vertical distance between the pair of upper and lower holding parts until the internal pressure detected by the sensor rises to a preset reference value, thereby making the injection holding distance smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, and the pair of upper and lower holding parts are each abutted against the tire in a circumferentially continuous annular shape, and while the tire is inflated by the cooling medium, the vertical distance between the pair of upper and lower holding parts is expanded from the injection holding distance to a preset reference distance, thereby maintaining the tire in an inflated state. Effect of the Invention

[0008] According to the present invention, the pair of upper and lower holding parts are each brought into contact with the tire in a continuous ring shape in the circumferential direction by making the holding interval at the time of injection smaller than the vertical interval between the upper and lower bead parts of the tire immediately after vulcanization when the tire is laid on its side. Therefore, even if the vertical interval between the upper and lower bead parts of the tire immediately after vulcanization becomes excessively narrow, it is advantageous to reliably inflate the tire by injecting the cooling medium into the tire. And, since the vertical interval between the pair of upper and lower holding parts is expanded from the holding interval at the time of injection to the standard interval and maintained in an inflated state, an appropriate PCI process is performed on the tire, and excellent tire quality can be ensured. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram illustrating an embodiment of a PCI device as viewed from the front with a tire in cross section. [Diagram 2] 2 is an explanatory diagram illustrating the PCI device of FIG. 1 in a plan view. [Diagram 3] 2 is a cross-sectional view taken along line AA in FIG. 1. [Figure 4] 4 is an explanatory diagram illustrating the movement of the engagement portion of FIG. 3. [Diagram 5] FIG. 2 is an explanatory diagram illustrating a state in which a tire immediately after vulcanization is placed on a lower holding portion. [Figure 6] 6 is an explanatory diagram illustrating a state in which the upper shaft and the lower shaft of FIG. 5 are connected. [Figure 7] 7 is an explanatory diagram illustrating a state in which the vertical distance between the pair of upper and lower holding parts in FIG. 6 is set to the holding distance during injection. FIG. [Figure 8] 8 is an explanatory diagram illustrating a state in which the vertical distance between the pair of upper and lower holding parts in FIG. 7 is expanded to a reference distance. [Figure 9] FIG. 13 is an explanatory diagram illustrating another embodiment of the PCI device as viewed from the front with the tire in cross section. [Figure 10] 10 is an explanatory diagram illustrating the PCI device of FIG. 9 in a plan view. [Figure 11] 10 is an explanatory diagram illustrating a state in which the vertical distance between the pair of upper and lower holding parts in FIG. 9 is set to the holding distance during injection. FIG. [Figure 12] FIG. 13 is an explanatory diagram illustrating another embodiment of the PCI device as viewed from the front with the tire in cross section. [Figure 13] 13 is an explanatory diagram illustrating a state in which the vertical distance between the pair of upper and lower holding parts in FIG. 12 is set to the holding distance during injection. FIG. [Figure 14] FIG. 13 is an explanatory diagram illustrating another embodiment of the PCI device as viewed from the front with the tire in cross section. [Figure 15] 15 is an explanatory diagram illustrating a state in which the vertical distance between the pair of upper and lower holding parts in FIG. 14 is set to the holding distance during injection. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a post cure inflation method and apparatus for tires according to the present invention will be described with reference to the embodiments shown in the drawings.

[0011] A post-cure inflation process (hereinafter referred to as a PCI process) is performed using an embodiment of a post-cure inflation apparatus 1 (hereinafter referred to as a PCI apparatus 1) illustrated in Figures 1 to 4. The procedure for performing this PCI process is the post-cure inflation method (hereinafter referred to as a PCI method) of the present invention.

[0012] In this tire T, thermally shrinkable fiber cords are embedded as reinforcing materials (such as carcass materials). Therefore, when the tire T is naturally cooled after vulcanization, the fiber cords thermally shrink, causing unnecessary deformation in the tire T. Therefore, by cooling the tire T in an inflated state immediately after vulcanization (by performing the PCI process), unnecessary deformation of the tire T is avoided by countering the thermal shrinkage of the fiber cords. The PCI process is performed with the tire T lying on its side immediately after vulcanization. In the tire T lying on its side, the two annular bead portions Tb face each other vertically.

[0013] This PCI device 1 includes a pair of upper and lower holding sections 5a, 5b that hold the upper and lower bead sections Tb of a tire T that is laid on its side immediately after vulcanization, a holding section moving mechanism 8, 8, an injection section 6 that injects a cooling medium C into the interior of the tire T, a gap sensor 9, a pressure sensor 10 that detects the internal pressure Pi of the tire T, and a control section 11.

[0014] In the PCI process, the vertical distance between the pair of upper and lower holding parts 5a, 5b is set to a reference distance Dc. This reference distance Dc is the vertical distance between the lowest position of the upper holding part 5a and the highest position of the lower holding part 5b. This reference distance Dc is substantially the same as the vertical distance between the pair of upper and lower bead parts Tb in the mold in which the tire T is vulcanized (the vertical distance between the lowest position of the upper bead part Tb and the highest position of the lower bead part Tb). In other words, the reference distance Dc is set to a dimension substantially the same as the vertical distance between the pair of upper and lower bead parts Tb when the vulcanized tire T is in the mold that is closed.

[0015] The upper holding portion 5a is attached to the upper shaft 2a, and the lower holding portion 5b is attached to the lower shaft 2b. The upper shaft 2a and the lower shaft 2b extend vertically on the same axis, and can be connected and disconnected to each other via a coupler 4. The upper shaft 2a and the lower shaft 2b are connected to form a single support shaft 2. The dashed line CL in the figure indicates the axis of the support shaft 2 (upper shaft 2a and lower shaft 2b).

[0016] The support shaft 2 penetrates through the center of each of the disk-shaped holding portions 5a, 5b in a plan view. At least one of the upper shaft 2a and the lower shaft 2b moves up and down, causing them to approach and move away from each other. In this embodiment, an engagement portion 3 is fixed to the lower end of the upper shaft 2a, and a cylindrical coupler 4 is fixed to the upper end of the lower shaft 2b.

[0017] As illustrated in Fig. 3, in a plan view, four engagement portions 3 extend radially from the upper shaft 2a around the axis CL. A through hole 4b having a shape corresponding to the upper shaft 2a and the four engagement portions 3 is formed in the upper surface of the coupler 4. By forming the through hole 4b, the engagement portion 4a is also formed in the upper surface of the coupler 4. The engagement portion 3 fixed to the lower end of the upper shaft 2a can be inserted vertically through the through hole 4b. Note that in Fig. 3, the inner peripheral edge of the tire T held by the lower holding portion 5b is indicated by a two-dot chain line.

[0018] To explain the connection structure between the upper shaft 2a and the lower shaft 2b in detail, as shown in Fig. 4, when the upper shaft 2a is rotated around the axis CL by a drive motor or the like so that the shape of the through hole 4b matches that of the engagement part 3 fixed to the lower end of the upper shaft 2a, the upper shaft 2a is moved up and down at the rotated position, and the engagement part 3 fixed to the lower end of the upper shaft 2a is inserted vertically through the through hole 4b. After the engagement part 3 is moved downward to insert it through the through hole 4b, the upper shaft 2a is rotated around the axis CL to a position where the engagement part 3 and the engagement part 4a overlap vertically as shown in Fig. 3. Even if the upper shaft 2a is moved upward, the engagement part 3 and the engagement part 4a interfere with each other, restricting the upward movement of the upper shaft 2a, and the upper shaft 2a and the lower shaft 2b are connected to each other to form a single support shaft 2. To release the connection between the upper shaft 2a and the lower shaft 2b, the procedure for connection is performed in reverse. The structure for connecting the upper shaft 2a and the lower shaft 2b is not limited to the structure exemplified in this embodiment, and various known structures can be adopted.

[0019] The upper holding portion 5a holds the upper portion (including the upper bead portion Tb) of the tire T laid on its side. The upper shaft 2a penetrates the center of the upper holding portion 5a in a plan view, and a holding portion moving mechanism 8 (upper holding portion moving mechanism 8) is installed to move the upper holding portion 5a up and down relative to the upper shaft 2a. As the holding portion moving mechanism 8, a known mechanism for moving the upper holding portion 5a up and down using a fluid cylinder, a servo motor, or the like can be used. The upper holding portion 5a can be fixed at a predetermined vertical position of the upper shaft 2a. In addition, the upper holding portion 5a can be moved up and down together with the upper shaft 2a by a fluid cylinder (not shown) or the like.

[0020] The lower holding portion 5b holds the lower portion (including the lower bead portion Tb) of the tire T that has been laid down on its side. The lower holding portion 5b has a connecting portion 4 that is integrated with the lower shaft 2b penetrating the center portion in a plan view, and a holding portion moving mechanism 8 (lower holding portion moving mechanism 8) that moves the lower holding portion 5b up and down is installed. The lower holding portion 5b can be fixed at a predetermined vertical position of the coupler 4 (lower shaft 2b) by the lower holding portion moving mechanism 8. The lower holding portion 5b can be moved up and down together with the lower shaft 2b and the coupler 4. As the holding portion moving mechanism 8, a known mechanism that moves the lower holding portion 5b up and down using a fluid cylinder, a servo motor, or the like can be used.

[0021] The injection unit 6 injects the cooling medium C, such as air, into the inside of the tire T. A known compressor or the like can be used as the injection unit 6. In this embodiment, the cooling medium C is injected into the inside of the tire T from an injection port 6a formed in the lower holding portion 5b. The injection port 6a is not limited to being formed in the lower holding portion 5b, but may be formed in the upper holding portion 5a, the support shaft 2, or the coupler 4, and may be formed in a plurality of locations rather than in one location.

[0022] Each of the holding part moving mechanisms 8, 8 may be any mechanism capable of reducing the vertical distance between the pair of upper and lower holding parts 5a, 5b to the holding distance Di during injection, which will be described later. If the vertical distance between the pair of upper and lower holding parts 5a, 5b is reduced to the holding distance Di during injection by moving both of the pair of upper and lower holding parts 5a, 5b up and down, a holding part moving mechanism 8, 8 for moving each of the holding parts 5a, 5b up and down is required. If the vertical distance between the pair of upper and lower holding parts 5a, 5b is reduced to the holding distance Di during injection by moving one of the pair of upper and lower holding parts 5a, 5b up and down, only a holding part moving mechanism 8 for moving one of the holding parts 5a, 5b up and down is required.

[0023] The gap sensor 9 detects the vertical gap g between the upper retaining portion 5a and the surface of the tire T facing the retaining portion 5a (the periphery of the upper bead portion Tb). The gap sensor 9 can be of various known non-contact types such as a photoelectric sensor. The vertical gap g detected by the gap sensor 9 is input to the control unit 11. The gap sensors 9 are installed at locations spaced apart in the circumferential direction around the axis CL. In this embodiment, the gap sensors 9 are installed at three locations at equal intervals in the circumferential direction, but it is preferable to install the gap sensors 9 at two to four locations at equal intervals.

[0024] The pressure sensor 10 may be of any of various known types capable of detecting the internal pressure Pi of the tire T. The internal pressure Pi detected by the pressure sensor 10 is input to the control unit 11.

[0025] The control unit 11 performs various calculation processes using the input data. The control unit 11 also controls the movements of the components of the PCI device 1 based on the input data and the calculation results. Various known computers can be used as the control unit 11. The above-mentioned reference interval Dc is input to and stored in the control unit 11.

[0026] One of the features of the PCI device 1 is that it has a gap reduction mechanism 7 that sets the vertical gap between the pair of upper and lower holding parts 5a, 5b to an injection-time holding gap Di that is smaller than the vertical gap Db between the upper and lower bead parts Tb of the tire T immediately after vulcanization that is laid on its side. In this embodiment, a holding part moving mechanism 8 that moves the lower holding part 5b up and down, a gap sensor 9, and a control part 11 function as the gap reduction mechanism 7.

[0027] An example of the procedure of a PCI process according to the PCI method will be described below.

[0028] In the PCI device 1 illustrated in Fig. 5, the upper shaft 2a and the upper holding portion 5a are in a standby position spaced far above the coupler 4, the lower shaft 2b, and the lower holding portion 5b. With the upper shaft 2a and the upper holding portion 5a in the standby position, the tire T immediately after vulcanization, which is laid on its side, is placed and held on the lower holding portion 5b. The lower bead portion Tb is held by the lower holding portion 5b, and the uppermost position of the lower holding portion 5b and the uppermost position of the lower bead portion Tb are substantially at the same level.

[0029] In the case of a tire T with a thin tire side portion immediately after vulcanization, the upper bead portion Tb is likely to sag due to the influence of a decrease in rigidity of the upper tire side portion, etc. As a result, the vertical distance Db between the upper and lower bead portions Tb of the tire T becomes smaller than the reference distance Dc.

[0030] Next, as illustrated in Fig. 6, the upper shaft 2a is moved downward from the standby position to the connected position together with the upper holding portion 5a. At this connected position, as illustrated in Figs. 3 and 4, the engagement portion 3 and the engagement portion 4a are vertically overlapped to connect the upper shaft 2a and the lower shaft 2b via the coupler 4 to form a single support shaft 2. In this embodiment, when the upper shaft 2a and the lower shaft 2b are connected as illustrated in Fig. 6, the vertical distance between the pair of upper and lower holding portions 5a, 5b is configured to be the reference distance Dc.

[0031] Since the vertical interval Db between the upper and lower bead portions Tb is smaller than the reference interval Dc, a large vertical gap g is generated between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, as illustrated in FIG. 7, the vertical positions of the upper shaft 2a and the upper holding portion 5a are fixed, and the lower holding portion 5b is moved upward together with the lower shaft 2b and the coupler 4 by the lower holding portion moving mechanism 8 while the vertical gap g is detected by the gap sensor 9. The lower holding portion 5b is moved upward together with the lower shaft 2b and the coupler 4 until the vertical gap g detected by the gap sensor 9 becomes zero, thereby reducing the vertical gap between the pair of upper and lower holding portions 5a, 5b. The vertical gap between the pair of upper and lower holding portions 5a, 5b when the vertical gap g becomes zero becomes the holding interval Di at the time of injection.

[0032] By setting the vertical distance between the pair of upper and lower holding portions 5a, 5b to the holding distance Di during injection, the pair of upper and lower holding portions 5a, 5b each abuts on the tire T in a circumferentially continuous annular shape. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower holding portions 5a, 5b.

[0033] 6, the upper holding portion 5a can be moved downward by the upper holding portion moving mechanism 8 while the vertical position of the upper shaft 2a is fixed and the vertical positions of the lower holding portion 5b together with the lower shaft 2b and the coupler 4 are kept fixed, and the vertical gap g is detected by the gap sensor 9. Then, the upper holding portion 5a is moved downward until the vertical gap g detected by the gap sensor 9 becomes zero, and the vertical distance between the pair of upper and lower holding portions 5a, 5b is set to the holding distance Di during injection. By moving the upper holding portion 5a in this manner, the pair of upper and lower holding portions 5a, 5b can also be brought into contact with the tire T in a continuous annular shape in the circumferential direction.

[0034] In a state where the pair of upper and lower holding parts 5a, 5b are in contact with the tire T in a continuous annular shape in the circumferential direction, the cooling medium C supplied from the injection part 6 does not substantially flow out to the outside of the tire T, so that the tire T can be smoothly inflated by the cooling medium C. Therefore, as illustrated in Fig. 8, while the tire T is inflated by the cooling medium C injected into the tire T, the vertical interval between the pair of upper and lower holding parts 5a, 5b is expanded from the injection holding interval Di to a preset reference interval Dc to maintain the tire T in an inflated state. When the vertical interval between the pair of upper and lower holding parts 5a, 5b is the reference interval Dc, the lowest position of the upper holding part 5a and the lowest position of the upper bead part Tb are substantially at the same level, and the highest position of the lower holding part 5b and the highest position of the lower bead part Tb are substantially at the same level.

[0035] In this embodiment, the upper shaft 2a and the upper retaining portion 5a are kept fixed in their vertical positions, and the lower shaft 2b and the coupler 4 are free to move vertically together with the lower retaining portion 5b. As a result, the upper and lower bead portions Tb are held by the upper and lower pair of retaining portions 5a, 5b, respectively, and the tire T is inflated, while the lower retaining portion 5b moves downward together with the lower shaft 2b and the coupler 4. The downward moving engaging portion 4a interferes with the engaging portion 3, thereby stopping the downward movement of the lower retaining portion 5b, and the vertical distance between the pair of upper and lower retaining portions 5a, 5b is maintained at the reference distance Dc.

[0036] The lower holding portion 5b can be moved downward together with the lower shaft 2b and the coupler 4 by the lower holding portion moving mechanism 8, thereby enlarging the vertical distance between the pair of upper and lower holding portions 5a, 5b from the holding distance Di during injection to the standard distance Dc. Alternatively, the upper holding portion 5a can be moved upward by the upper holding portion moving mechanism 8, thereby enlarging the vertical distance between the pair of upper and lower holding portions 5a, 5b from the holding distance Di during injection to the standard distance Dc.

[0037] The control unit 11 controls the amount of cooling medium C injected from the injection unit 6 so that the internal pressure Pi detected by the pressure sensor 10 falls within a predetermined range, and maintains the tire T in an inflated state and cools it for a predetermined time. Then, when the predetermined cooling time has elapsed, the PCI process ends. Thereafter, the upper shaft 2a and the lower shaft 2b are released from connection, and the upper shaft 2a and the upper holding unit 5a are moved upward to the standby position, and the tire T for which the PCI process has been completed is removed from the PCI device 1.

[0038] As described above, by making the holding interval Di at the time of injection smaller than the vertical interval Db between the upper and lower bead portions Tb of the tire T immediately after vulcanization when laid on its side, the pair of upper and lower holding portions 5a, 5b are each brought into a state of being in contact with the tire T in a continuous ring shape in the circumferential direction. By bringing the tire T into this state, even if the vertical interval Db between the upper and lower bead portions Tb of the tire T immediately after vulcanization becomes excessively narrow, it is advantageous for reliably inflating the tire T by injecting the cooling medium C into the tire T. Subsequently, the vertical interval between the pair of upper and lower holding portions 5a, 5b is expanded from the holding interval Di at the time of injection to the reference interval Dc to maintain the tire T in an inflated state, so that an appropriate PCI process can be performed on the tire T. As a result, deformation of the tire T caused by thermal contraction of the fiber cord can be avoided, and excellent tire quality can be ensured.

[0039] Next, other embodiments will be described. The embodiment of the PCI device 1 illustrated in Fig. 9 to Fig. 11 differs from the first embodiment illustrated in Fig. 1 to Fig. 4 in that a pressure sensor 10a is provided instead of the gap sensor 9, and the other configurations are substantially the same as those of the first embodiment. The pressure sensor 10a detects the outflow pressure Pa of the cooling medium C flowing out from inside to outside of the tire T through a vertical gap g between the upper holding portion 5a and a surface of the tire T facing the holding portion 5a (the peripheral portion of the upper bead portion Tb).

[0040] The pressure sensor 10a may be of various known types capable of detecting the outflow pressure Pa of the cooling medium C. The outflow pressure Pa detected by the pressure sensor 10a is input to the control unit 11. The pressure sensors 10a are installed at locations spaced apart in the circumferential direction around the axis CL. In this embodiment, the pressure sensors 10a are installed at three locations at equal intervals in the circumferential direction, but it is preferable to install the pressure sensors 10a at two to four locations at equal intervals. In this embodiment, the holding part moving mechanism 8 that moves the lower holding part 5b up and down, the pressure sensors 10a, and the control unit 11 function as the interval reduction mechanism 7.

[0041] An example of the procedure of the PCI process according to this embodiment will now be described.

[0042] 9, the tire T is placed on the lower holding portion 5b and held, and the upper axle 2a and the lower axle 2b are connected via a coupler 4 to form a single support axle 2, which is the same as in the first embodiment. There is a large vertical gap g between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, in this embodiment, the cooling medium C is injected into the tire T from the injection portion 6, and the outflow pressure Pa of the cooling medium C flowing out from the vertical gap g is detected by the pressure sensor 10a.

[0043] 11, while the upper shaft 2a and the upper holding portion 5a are kept fixed in their vertical positions, the lower holding portion 5b is moved upward together with the lower shaft 2b and the coupler 4 while the cooling medium C is injected into the tire T from the injection portion 6 and the outflow pressure Pa is detected by the pressure sensor 10a. The lower holding portion 5b is moved upward together with the lower shaft 2b and the coupler 4 until the outflow pressure Pa detected by the pressure sensor 10a becomes zero, thereby reducing the vertical distance between the pair of upper and lower holding portions 5a, 5b. The vertical distance between the pair of upper and lower holding portions 5a, 5b when the outflow pressure Pa becomes zero becomes the injection-time holding distance Di.

[0044] By setting the vertical interval between the pair of upper and lower retaining parts 5a, 5b to the holding interval Di at the time of injection, the pair of upper and lower retaining parts 5a, 5b each abut against the tire T in a continuous ring shape in the circumferential direction. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower retaining parts 5a, 5b. Therefore, similar to the first embodiment, the tire T can be smoothly inflated by the cooling medium C. Then, similar to the first embodiment, while inflating the tire T with the cooling medium C injected inside the tire T, the vertical interval between the pair of upper and lower retaining parts 5a, 5b is expanded from the holding interval Di at the time of injection to a preset reference interval Dc, and the tire T is maintained in an inflated state and cooled for a predetermined time.

[0045] The procedure thereafter is the same as in embodiment 1. In this embodiment as well, the various modifications described in embodiment 1 can be implemented.

[0046] Next, another embodiment will be described. The embodiment of the PCI device 1 illustrated in Fig. 12 and Fig. 13 is different from the first embodiment in that a pressure sensor 10b is provided instead of the gap sensor 9, and other configurations are substantially the same as those of the first embodiment. The pressure sensor 10b detects the contact pressure Pb between the upper retaining portion 5a and the surface of the tire T facing the retaining portion 5a (the periphery of the upper bead portion Tb).

[0047] The pressure sensor 10b may be of various known types capable of detecting the contact pressure Pb. The contact pressure Pb detected by the pressure sensor 10b is input to the control unit 11. The pressure sensors 10b are installed at locations spaced apart in the circumferential direction around the axis CL, and it is preferable to install the pressure sensors 10b at two to four locations at equal intervals in the circumferential direction. In this embodiment, the holding part moving mechanism 8 that moves the lower holding part 5b up and down, the pressure sensor 10b, and the control unit 11 function as the gap reduction mechanism 7.

[0048] An example of the procedure of the PCI process according to this embodiment will now be described.

[0049] As shown in Fig. 12, the process is the same as that of the first embodiment, from placing and holding a tire T laid on its side on the lower holding portion 5b, to connecting the upper shaft 2a and the lower shaft 2b via a coupler 4 to form a single support shaft 2. There is a large vertical gap g between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, in this embodiment, the contact pressure Pb is detected by the pressure sensor 10b. When there is a vertical gap g, the contact pressure Pb is zero.

[0050] As illustrated in FIG. 13, the upper shaft 2a and the upper retaining portion 5a are fixed in their vertical positions, and the lower retaining portion 5b is moved upward together with the lower shaft 2b and the coupler 4 while the contact pressure Pb is detected by the pressure sensor 10b. The lower retaining portion 5b is moved upward together with the lower shaft 2b and the coupler 4 until the contact pressure Pb detected by the pressure sensor 10b rises to a preset reference value, thereby reducing the vertical distance between the pair of upper and lower retaining portions 5a, 5b. The vertical distance between the pair of upper and lower retaining portions 5a, 5b when the contact pressure Pb reaches the reference value becomes the retention distance Di during injection. This reference value may be determined by performing a preliminary test or the like and adopting the minimum contact pressure Pb within a range that can guarantee that the pair of upper and lower retaining portions 5a, 5b are in continuous annular contact with the tire T in the circumferential direction.

[0051] By setting the vertical interval between the pair of upper and lower retaining parts 5a, 5b to the holding interval Di at the time of injection, the pair of upper and lower retaining parts 5a, 5b each abut against the tire T in a continuous ring shape in the circumferential direction. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower retaining parts 5a, 5b. Therefore, similar to the first embodiment, the tire T can be smoothly inflated by the cooling medium C. Then, similar to the first embodiment, while inflating the tire T with the cooling medium C injected inside the tire T, the vertical interval between the pair of upper and lower retaining parts 5a, 5b is expanded from the holding interval Di at the time of injection to a preset reference interval Dc, and the tire T is maintained in an inflated state and cooled for a predetermined time.

[0052] The procedure thereafter is the same as in embodiment 1. In this embodiment as well, the various modifications described in embodiment 1 can be implemented.

[0053] Next, another embodiment will be described. The embodiment of the PCI device 1 illustrated in Fig. 14-Fig. 15 is different from the first embodiment in that the gap sensor 9 is omitted, and other configurations are substantially the same as the first embodiment. In this embodiment, a pressure sensor 10 is further utilized, and the holder moving mechanism 8 that moves the lower holder 5b up and down, the pressure sensor 10, and the control unit 11 function as the gap reduction mechanism 7.

[0054] An example of the procedure of the PCI process according to this embodiment will now be described.

[0055] 14, the tire T is placed on the lower holding portion 5b and held, and the upper axle 2a and the lower axle 2b are connected via a coupler 4 to form a single support axle 2, which is the same as in the first embodiment. There is a large vertical gap g between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, in this embodiment, a cooling medium C is injected into the tire T from an injection portion 6, and the internal pressure Pi of the tire T is detected by a pressure sensor 10.

[0056] As illustrated in FIG. 15, the upper shaft 2a and the upper holding portion 5a are fixed in their vertical positions, and the lower shaft 2b and the coupler 4 are moved upward while the cooling medium C is injected into the tire T from the injection portion 6 and the internal pressure Pi is detected by the pressure sensor 10. The lower holding portion 5b is moved upward together with the lower shaft 2b and the coupler 4 until the internal pressure Pi detected by the pressure sensor 10 rises to a preset reference value, thereby reducing the vertical distance between the pair of upper and lower holding portions 5a, 5b. The vertical distance between the pair of upper and lower holding portions 5a, 5b when the internal pressure Pi reaches the reference value is the holding distance Di during injection. This reference value may be determined by performing a preliminary test or the like and adopting the minimum internal pressure Pi within a range that can guarantee that the pair of upper and lower holding portions 5a, 5b are in continuous annular contact with the tire T in the circumferential direction.

[0057] By setting the vertical interval between the pair of upper and lower retaining parts 5a, 5b to the holding interval Di at the time of injection, the pair of upper and lower retaining parts 5a, 5b each abut against the tire T in a continuous ring shape in the circumferential direction. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower retaining parts 5a, 5b. Therefore, similar to the first embodiment, the tire T can be smoothly inflated by the cooling medium C. Then, similar to the first embodiment, while the tire T is smoothly inflated by the cooling medium C injected inside the tire T, the vertical interval between the pair of upper and lower retaining parts 5a, 5b is expanded from the holding interval Di at the time of injection to a preset reference interval Dc, and the tire T is maintained in an inflated state and cooled for a predetermined time.

[0058] The procedure thereafter is the same as in embodiment 1. In this embodiment as well, the various modifications described in embodiment 1 can be implemented.

[0059] A description will be given of another embodiment (another PCI method) using the same configuration as the embodiment of the PCI device 1 illustrated in Figures 14 and 15. In this embodiment, a holder moving mechanism 8 that moves the lower holder 5b up and down and a control unit 11 function as a gap reduction mechanism 7.

[0060] In this embodiment, the actual value of the vertical distance Db between the upper and lower bead portions Tb of the tire T immediately after vulcanization while laid on its side is grasped in advance by performing a preliminary test or the like for each specification of the tire T. Then, the holding distance Di during injection is set to 80% to 95% of this actual value and input to the control unit 11.

[0061] An example of the procedure of the PCI process according to this embodiment will be described. As illustrated in FIG. 14, the tire T is placed on the lower holding portion 5b and held, and the upper shaft 2a and the lower shaft 2b are connected via a coupler 4 to form a single support shaft 2, which is the same as the first embodiment. There is a large vertical gap g between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, in this embodiment, the vertical gap between the pair of upper and lower holding portions 5a, 5b is reduced so that the injection holding interval Di becomes equal to the injection holding interval Di set based on the actual value input to the control unit 11. In this embodiment, the cooling medium C is not injected into the tire T until it reaches the injection holding interval Di.

[0062] That is, as illustrated in Fig. 15, the upper shaft 2a and the upper retaining portion 5a are fixed in their vertical positions, and the lower shaft 2b and the coupler 4 are moved upward to set the vertical interval between the pair of upper and lower retaining portions 5a, 5b to the retention interval Di at injection. This retention interval Di at injection is set slightly smaller than the actual value of the vertical interval Db between the upper and lower bead portions Tb of the tire T immediately after vulcanization in a lying position. Therefore, by setting the vertical interval between the pair of upper and lower retaining portions 5a, 5b to the retention interval Di at injection, the pair of upper and lower retaining portions 5a, 5b each abut against the tire T in a ring shape that is continuous in the circumferential direction. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower retaining portions 5a, 5b, so that the tire T can be smoothly inflated by the cooling medium C, as in the first embodiment. Then, as in the first embodiment, the tire T is inflated with the cooling medium C injected inside the tire T, while the vertical distance between the pair of upper and lower retaining portions 5a, 5b is expanded from the retention distance Di at the time of injection to a preset reference distance Dc, and the tire T is maintained in an inflated state and cooled for a predetermined time.

[0063] The procedure thereafter is the same as in embodiment 1. In this embodiment as well, the various modifications described in embodiment 1 can be implemented.

[0064] If the injection holding interval Di is set to more than 95% of the above-mentioned actual value, there is a risk that the pair of upper and lower holding portions 5a, 5b cannot be brought into contact with the tire T in a continuous annular shape in the circumferential direction. On the other hand, if the injection holding interval Di is set to less than 80% of the above-mentioned actual value, the tire T is cooled by the injected cooling medium C in a state in which the tire T is excessively crushed in the vertical direction. Since the shape of the tire T during initial cooling is likely to be reflected in the shape of the tire T after the PCI process is completed, in order to avoid unnecessary deformation of the tire T, it is preferable to set the injection holding interval Di to 80% or more of the above-mentioned actual value.

[0065] A further embodiment (another PCI method) using the same configuration as the embodiment of the PCI device 1 illustrated in Figures 14 and 15 will be described. In this embodiment as well, a holder moving mechanism 8 that moves the lower holder 5b up and down and a control unit 11 function as the interval reduction mechanism 7. In this embodiment, the control unit 11 sets the holding interval during injection Di to 20% to 60% of the reference interval Dc.

[0066] An example of the procedure of the PCI process according to this embodiment will be described. As illustrated in FIG. 14, the tire T is placed on the lower holding portion 5b and held, and the upper shaft 2a and the lower shaft 2b are connected via the coupler 4 to form a single support shaft 2, which is the same as the first embodiment. There is a large vertical gap g between the upper holding portion 5a and the surface of the tire T facing the holding portion 5a (the periphery of the upper bead portion Tb). Therefore, in this embodiment, the vertical gap between the pair of upper and lower holding portions 5a, 5b is reduced so that it becomes the injection holding interval Di set based on the reference interval Dc input to the control unit 11. In this embodiment, the cooling medium C is not injected into the tire T until it reaches the injection holding interval Di.

[0067] That is, as illustrated in FIG. 15, the upper shaft 2a and the upper holding portion 5a are fixed in their vertical positions, and the lower shaft 2b and the coupler 4 are moved upward to set the vertical interval between the pair of upper and lower holding portions 5a, 5b to the holding interval Di at the time of injection. Since this holding interval Di at the time of injection is set to be very small compared to the reference interval Dc, by setting the vertical interval between the pair of upper and lower holding portions 5a, 5b to the holding interval Di at the time of injection, the pair of upper and lower holding portions 5a, 5b each abut against the tire T in a ring shape that is continuous in the circumferential direction. Accordingly, the internal space of the tire T becomes a closed space surrounded by the tire T and the pair of upper and lower holding portions 5a, 5b. Therefore, similar to the first embodiment, the tire T can be smoothly inflated by the cooling medium C. Then, as in the first embodiment, the tire T is inflated with the cooling medium C injected inside the tire T, while the vertical distance between the pair of upper and lower retaining portions 5a, 5b is expanded from the retention distance Di at the time of injection to a preset reference distance Dc, and the tire T is maintained in an inflated state and cooled for a predetermined time.

[0068] The procedure thereafter is the same as in embodiment 1. In this embodiment as well, the various modifications described in embodiment 1 can be implemented.

[0069] If the injection holding interval Di is more than 60% of the reference interval Dc, there is a risk that the pair of upper and lower holding portions 5a, 5b cannot be brought into contact with the tire T in a continuous annular shape in the circumferential direction. On the other hand, if the injection holding interval Di is less than 20% of the reference interval Dc, the tire T is cooled by the injected cooling medium C in a state in which the tire T is excessively crushed in the vertical direction. Since the shape of the tire T during initial cooling is likely to be reflected in the shape of the tire T after the PCI process is completed, in order to avoid unnecessary deformation of the tire T, it is preferable to set the injection holding interval Di to 20% or more of the above-mentioned actual value, and more preferably 40% or more.

[0070] The interval reduction mechanism 7 used in each of the above-mentioned embodiments can be applied in a combination of multiple types within a range where combinations are possible. When multiple types of interval reduction mechanisms 7 are applied in combination, the reduction of the vertical interval between the pair of upper and lower holding parts 5a, 5b may be stopped at the point in time when any of the interval reduction mechanisms 7 determines that the interval is the interval Di during injection. In addition, in order to set the vertical interval between the pair of upper and lower holding parts 5a, 5b to the interval Di during injection, it is possible to use a specification in which only one of the pair of upper and lower holding parts 5a, 5b is moved vertically, but there is an advantage in that the amount of vertical movement of each of the pair of upper and lower holding parts 5a, 5b can be reduced by using a specification in which each of the pair of upper and lower holding parts 5a, 5b is moved vertically independently of each other.

[0071] The present disclosure encompasses the following inventions: [Invention 1] A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state. [Invention 2] A post-cure inflation method for tires as described in [Invention 1], in which the tire is placed on its side and held on the lower holding portion, the vertical gap between the upper holding portion and the surface of the tire facing this holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected vertical gap becomes zero, thereby setting the vertical distance between the pair of upper and lower holding portions to the holding distance at time of injection. [Invention 3] A post-cure inflation method for tires as described in [Invention 1] or [Invention 2], in which the tire is placed on its side and held on the lower holding part, the outflow pressure of the cooling medium flowing from the inside of the tire to the outside through the vertical gap between the upper holding part and the surface of the tire facing this holding part is detected by a sensor, and the vertical distance between the pair of upper and lower holding parts is reduced until the detected outflow pressure becomes zero, thereby setting the vertical distance between the pair of upper and lower holding parts to the holding distance at time of injection. [Invention 4] A post-cure inflation method for tires described in any one of [Invention 1] to [Invention 3], in which the tire is placed on its side and held on the lower holding portion, the contact pressure between the upper holding portion and the surface of the tire facing this holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected contact pressure rises to a predetermined reference value, thereby setting the vertical distance between the pair of upper and lower holding portions to the holding distance at time of injection. [Invention 5] A post-cure inflation method for a tire described in any one of [Invention 1] to [Invention 4], in which the tire is placed on its side and held on the lower holding portion, the internal pressure of the tire is detected by a sensor while the cooling medium is injected into the inside of the tire, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected internal pressure rises to a predetermined reference value, thereby setting the vertical distance between the pair of upper and lower holding portions to the holding distance at time of injection. [Invention 6] A post-cure inflation method for a tire described in any one of [Invention 1] to [Invention 5], in which an actual value of the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization while laid on its side is determined in advance for each tire specification, and the holding distance at the time of injection is set to 80% or more and 95% or less of the actual value. [Invention 7] The tire post-cure inflation method according to any one of [Invention 1] to [Invention 5], wherein the holding interval during injection is set to 20% to 60% of the reference interval. [Invention 8] A post-cure inflation method for a tire described in any one of [Invention 1] to [Invention 7], in which the pair of upper and lower holding parts are moved up and down independently of each other, so that the vertical distance between the pair of upper and lower holding parts is set to the holding distance at the time of injection. [Invention 9] A tire post-cure inflation device comprising a pair of upper and lower holding sections for holding upper and lower bead sections of a tire immediately after vulcanization that is laid on its side, and an injection section for injecting a cooling medium into the tire, the tire being maintained in an inflated state by the cooling medium, A tire post-cure inflation device having a gap reduction mechanism which reduces the vertical gap between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, and the gap reduction mechanism causes the vertical gap between the pair of upper and lower holding portions to be an injection time holding gap which is smaller than the vertical gap between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, so that the pair of upper and lower holding portions are each abutted against the tire in a circumferentially continuous annular shape, and while the tire is inflated with the cooling medium, the vertical gap between the pair of upper and lower holding portions is expanded from the injection time holding gap to a predetermined standard gap, thereby maintaining the tire in an inflated state. [Explanation of symbols]

[0072] 1 PCI device 2 spindle 2a Upper axis 2b Lower axis 3 Engagement part 4 coupler 4a Engagement part 4b Through hole 5a One of the holding parts 5b The other holding part 6 Injection part 6a Inlet 7 Spacing reduction mechanism 8 Holding part moving mechanism 9 Gap Sensor 10, 10a, 10b Pressure sensor 11 Control section T Vulcanized tires Tb Bead part C Cooling medium Db Vertical distance between upper and lower beads immediately after vulcanization Holding interval during Di injection Dc Reference Interval

Claims

1. A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, The tire is placed on its side and held on the lower holding portion, and a vertical gap between the upper holding portion and the surface of the tire facing the holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected vertical gap becomes zero, A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state.

2. A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, The tire is placed on its side and held on the lower holding portion, and an outflow pressure of the cooling medium flowing from inside the tire to the outside through a vertical gap between the upper holding portion and the surface of the tire facing the upper holding portion is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected outflow pressure becomes zero, A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state.

3. A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, The tire is placed on its side and held on the lower holding portion, and a sensor detects the contact pressure between the upper holding portion and the surface of the tire facing the upper holding portion, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected contact pressure increases to a preset reference value. A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state.

4. A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, The tire is placed on the lower holding portion and held thereon, and while the cooling medium is injected into the tire, the internal pressure of the tire is detected by a sensor, and the vertical distance between the pair of upper and lower holding portions is reduced until the detected internal pressure rises to a preset reference value. A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to an injection retention distance that is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state.

5. A post-cure inflation method for a tire, comprising: holding upper and lower bead portions of a tire immediately after vulcanization, which is laid on its side, with a pair of upper and lower holding portions; and injecting a cooling medium into the tire to maintain the tire in an inflated state, For each tire specification, a performance value of a vertical distance between the upper and lower bead portions of the tire immediately after vulcanization in a horizontal position is grasped in advance, and a holding distance during injection is set to 80% or more and 95% or less of the performance value; A post-cure inflation method for a tire, in which the vertical distance between the pair of upper and lower retaining parts is set to the injection retention distance which is smaller than the vertical distance between the upper and lower bead portions of the tire immediately after vulcanization when laid on its side, thereby abutting the pair of upper and lower retaining parts in a circumferentially continuous annular shape against the tire, and inflating the tire with the cooling medium, while expanding the vertical distance between the pair of upper and lower retaining parts from the injection retention distance to a predetermined standard distance to maintain the tire in an inflated state.

6. A tire post-cure inflation device comprising a pair of upper and lower holding sections for holding upper and lower bead sections of a tire immediately after vulcanization that is laid on its side, and an injection section for injecting a cooling medium into the tire, the tire being maintained in an inflated state by the cooling medium, a gap reduction mechanism for reducing a vertical gap between the upper and lower bead portions of the tire immediately after vulcanization in a state where the tire is laid on its side, The gap reduction mechanism is equipped with a sensor that detects the vertical gap between the upper holding portion and the surface facing the upper holding portion of the tire that is placed sideways on and held on the lower holding portion, and by reducing the vertical gap between the pair of upper and lower holding portions until the vertical gap detected by the sensor becomes zero, the injection time holding gap is set to be smaller than the vertical gap between the upper and lower bead portions of the tire immediately after vulcanization and placed on its side, and the pair of upper and lower holding portions are each abutted against the tire in a circumferentially continuous annular shape, and the tire is inflated with the cooling medium, while the vertical gap between the pair of upper and lower holding portions is expanded from the injection time holding gap to a predetermined standard gap, thereby maintaining the tire in an inflated state.

7. A tire post-cure inflation device comprising a pair of upper and lower holding sections for holding upper and lower bead sections of a tire immediately after vulcanization that is laid on its side, and an injection section for injecting a cooling medium into the tire, the tire being maintained in an inflated state by the cooling medium, a gap reduction mechanism for reducing a vertical gap between the upper and lower bead portions of the tire immediately after vulcanization in a state where the tire is laid on its side, a gap reduction mechanism for reducing the spacing between the upper holding portion and the surface of the tire facing the upper holding portion when the tire is placed sideways on the lower holding portion, the gap reduction mechanism reducing the spacing between the upper and lower holding portions until the spacing between the upper and lower holding portions becomes zero, thereby making the injection holding spacing smaller than the spacing between the upper and lower bead portions of the tire immediately after vulcanization when placed sideways, and each of the upper and lower holding portions abutting against the tire in a circumferentially continuous ring shape, and the tire being inflated with the cooling medium, the vertical spacing between the upper and lower holding portions being expanded from the injection holding spacing to a predetermined standard spacing to maintain the tire in an inflated state.

8. A tire post-cure inflation device comprising a pair of upper and lower holding sections for holding upper and lower bead sections of a tire immediately after vulcanization that is laid on its side, and an injection section for injecting a cooling medium into the tire, the tire being maintained in an inflated state by the cooling medium, a gap reduction mechanism for reducing a vertical gap between the upper and lower bead portions of the tire immediately after vulcanization in a state where the tire is laid on its side, The gap reduction mechanism is equipped with a sensor that detects contact pressure between the upper holding portion and a surface facing the upper holding portion of the tire placed sideways and held on the lower holding portion, and reduces the vertical gap between the pair of upper and lower holding portions until the contact pressure detected by the sensor rises to a preset reference value, thereby making the injection holding gap smaller than the vertical gap between the upper and lower bead portions of the tire immediately after vulcanization and placed sideways, and the pair of upper and lower holding portions are each abutted against the tire in a circumferentially continuous annular shape, and the tire is inflated with the cooling medium, while the vertical gap between the pair of upper and lower holding portions is expanded from the injection holding gap to a preset reference gap to maintain the tire in an inflated state.

9. A tire post-cure inflation device comprising a pair of upper and lower holding sections for holding upper and lower bead sections of a tire immediately after vulcanization that is laid on its side, and an injection section for injecting a cooling medium into the tire, the tire being maintained in an inflated state by the cooling medium, a gap reduction mechanism for reducing a vertical gap between the upper and lower bead portions of the tire immediately after vulcanization in a state where the tire is laid on its side, The gap reduction mechanism is equipped with a sensor which detects the internal pressure of the tire while the cooling medium is injected inside the tire which is placed on its side and held on the lower holding part, and reduces the vertical gap between the pair of upper and lower holding parts until the internal pressure detected by the sensor rises to a preset reference value, thereby making the injection holding gap smaller than the vertical gap between the upper and lower bead portions of the tire immediately after vulcanization and placed on its side, and the pair of upper and lower holding parts are each abutted against the tire in a circumferentially continuous annular shape, and the tire is inflated with the cooling medium while the vertical gap between the pair of upper and lower holding parts is expanded from the injection holding gap to a preset reference gap to maintain the tire in an inflated state.

Images