JP2021123090A - Tire vulcanizing apparatus and method - Google Patents

Abstract

To provide a tire vulcanizing apparatus and method capable of more reliably preventing a problem such that a green tire is bitten by a closing vulcanizing mold.SOLUTION: There is provided a tire vulcanizing apparatus that comprises: an opening/closing mechanism; a central mechanism; a vulcanizing medium pipe; a shaping pipe; and a discharge pipe, and further comprises: a tank 15 in a middle of a shaping pipe 13; and a piston part 17 that changes an accommodation volume of the tank 15; and on-off valves 16a and 16b in front of and behind the tank 15 of the pipe 13, in which after a green tire G is held and shaped by a vulcanizing bladder 5 expanded by supplying a shaping medium M1 into inside thereof, an increase of an internal pressure in the vulcanizing bladder 5 due to closing of the mold is suppressed by controlling opening and closing of the on-off valves 16a and 16b by a control unit 20 in a process of closing a vulcanizing mold 21, and by accommodating a part of the shaping medium M1 inside the vulcanizing bladder 5 into the tank 15 whose accommodating volume is increased by the piston portion 17 through the pipe 13.SELECTED DRAWING: Figure 5

Description

The present invention relates to a tire vulcanization apparatus and method, and more particularly to a tire vulcanization apparatus and method capable of more reliably preventing a problem in which a green tire is bitten by a closed vulcanization mold.

When vulcanizing a pneumatic tire, the vulcanization bladder inserted inside the green tire is expanded to apply shaping pressure to shape it, and then the vulcanization mold with this green tire placed inside is used. Close the mold. After that, the internal pressure of the vulcanizing bladder is further increased to expand the green tire, and the green tire is heated while being pressurized to vulcanize.

If the maximum outer diameter of the green tire is larger than the reference value when the vulcanization mold is closed, the green tire may be bitten by the closing vulcanization mold. Therefore, in order to prevent this problem, when the final shaping pressure is applied to the inside of the green tire, the maximum outer diameter of the green tire is sequentially detected by the sensor, and the final shaping pressure is adjusted based on this detection data. Has been proposed (see Patent Document 1).

However, since the side portion of the green tire is pressed by the vulcanization mold in the process of closing the mold after shaping, the internal pressure of the vulcanization bladder increases, and as a result, the maximum outer diameter of the green tire increases. Therefore, even if the final shaping pressure is adjusted, it may not be possible to prevent the above-mentioned biting problem, and there is room for improvement in order to prevent this problem more reliably.

Japanese Unexamined Patent Publication No. 2013-22790

An object of the present invention is to provide a tire vulcanization apparatus and method capable of more reliably preventing a problem in which a green tire is bitten by a closed vulcanization mold.

In order to achieve the above object, the tire vulcanization apparatus of the present invention has an opening / closing mechanism of a vulcanization mold, a central mechanism having a vulcanization bladder, and a pressure medium and a heating medium inside the vulcanization bladder. Addition of a tire including a vulcanization medium pipe to be supplied, a shaping pipe for supplying a shaping medium inside the vulcanization bladder, and a discharge pipe for discharging the medium inside the vulcanization bladder to the outside. In the vulcanization apparatus, a tank for accommodating the shaping medium at a position in the middle of the shaping pipe, an on-off valve for opening and closing the shaping pipe arranged at each position in front of and behind the tank of the shaping pipe, and accommodating the tank. It has a piston unit that changes the volume and a control unit that controls the opening and closing of each of the on-off valves.
In the process of closing the vulcanization mold, the control unit controls the opening and closing of each of the on-off valves, so that the vulcanization is performed through the shaping pipe in the tank whose accommodating volume is increased by the piston unit. It is characterized in that a part of the shaping medium inside the bladder is accommodated.

In the tire vulcanization method of the present invention, a shaping medium is supplied to the inside of the vulcanization bladder and expanded, the green tire is held by the vulcanization bladder, the green tire is shaped, and then the vulcanization mold is used. In the method of vulcanizing a tire in which a pressure medium and a heating medium are supplied to the inside of the vulcanization bladder and the inside of the green tire is pressed and heated by the vulcanization bladder.
A tank for accommodating the shaping medium is arranged inside the vulcanization bladder at a position in the middle of the shaping pipe for supplying the shaping medium, and a piston portion for changing the accommodating volume of the tank is provided. On-off valves for opening and closing the shaping pipe are arranged at the front and rear positions of the tank, and in the process of closing the vulcanization mold, the opening and closing of each on-off valve is controlled to control the opening and closing of the vulcanization bladder. By accommodating a part of the shaping medium inside the vulcanization medium into the tank whose accommodating volume is increased by the piston portion through the shaping pipe, the vulcanization bladder accompanying the closing of the vulcanization mold It is characterized by suppressing an increase in internal pressure.

According to the present invention, the tank is provided in the middle of the shaping pipe, and the on-off valves are arranged at the front and rear positions of the tank of the shaping pipe, so that the vulcanization mold is closed. In the process of controlling the opening and closing of each of the on-off valves, a part of the shaping medium inside the vulcanization bladder is accommodated in the tank whose accommodating volume is increased by the piston portion. It is possible to suppress an increase in the internal pressure of the vulcanization bladder due to the closing of the vulcanization mold. Along with this, it is possible to prevent the shaped green tire from being bitten by the vulcanization mold that closes. Then, by adjusting the movement of the shaping medium in a closed space in which the vulcanization bladder and the tank, which have variable accommodating volumes, are connected by a shaping pipe, this movement adjustment becomes more stable, and the above-mentioned problems are prevented. Will be advantageous to.

It is explanatory drawing which illustrates the tire vulcanization apparatus of this invention with a part in the vertical cross-sectional view of the right half. It is explanatory drawing which illustrates the container ring, a segment and a sector mold of FIG. 1 in a plan view. It is explanatory drawing which illustrates the state which arranges the green tire inside the vulcanization mold of FIG. 1 opened. It is explanatory drawing which illustrates the state which the green tire of FIG. 3 is shaping. It is explanatory drawing which illustrates the process of closing the vulcanization mold of FIG. It is explanatory drawing which illustrates the state in which the heating medium and the pressure medium are supplied to the inside of the vulcanization bladder of FIG. 5, and the green tire is vulcanized. It is explanatory drawing which illustrates the container ring, a segment and a sector mold of FIG. 6 in a plan view. It is explanatory drawing which illustrates the state in which the medium inside the vulcanization bladder is discharged to the outside after vulcanizing the green tire of FIG.

Hereinafter, the tire vulcanization apparatus and method of the present invention will be described based on the embodiment shown in the figure.

A vulcanization mold 21 (hereinafter referred to as a mold 21) corresponding to the green tire G to be vulcanized is attached to the embodiment of the tire vulcanization apparatus 1 of the present invention illustrated in FIGS. 1 and 2. In this embodiment, the vulcanization apparatus 1 is a sectional type mold 21 composed of an annular upper side mold 21a, an annular lower side mold 21b, and a plurality of arc-shaped sector molds 21c in a plan view. It is attached to.

The vulcanization apparatus 1 includes an opening / closing mechanism (hydraulic cylinders 3 and 9, which will be described later) for opening and closing the mold 21, a central mechanism 4 having a vulcanization bladder 5, a vulcanization medium pipe 10, and a shaping pipe 13. , The discharge pipe 18 is provided. Further, the vulcanizer 1 includes a tank 15 arranged at a position in the middle of the shaping pipe 13, on-off valves 16a and 16b arranged at positions before and after the tank 15 of the shaping pipe 13, and a storage volume of the tank 15. It has a piston unit 17 for changing the pressure sensor 19, a pressure sensor 19, and a control unit 20.

Above the central mechanism 4, a vertical movement plate 2 that moves up and down by a hydraulic cylinder 3 and a container ring 2a that is fixed to the vertical movement plate 2 and projects downward are provided. The vertical movement plate 2 and the container ring 2a move up and down integrally.

An upper plate 7a is arranged at a vertical position between the vertical movement plate 2 and the central mechanism 4. A plurality of arcuate segments 8 are attached to the lower surface of the upper plate 7a in a plan view. The upper plate 7a is moved up and down by the hydraulic cylinder 9. The vertical movement plate 2 and the upper plate 7a can be moved up and down independently of each other. The lower plate 7b is immovably fixed to the ground base so as to face the upper plate 7a.

In the central mechanism 4, a disk-shaped clamp portion 6 is attached to the central post 4a and the central post 4a at intervals of upper and lower parts. The central post 4a penetrates the lower plate 7b up and down. The upper end portion and the lower end portion of the cylindrical vulcanization bladder 5 are gripped on each of the clamp portions 6. The alternate long and short dash line CL in the figure indicates the central position of the central post 4a.

The upper surface of the upper side mold 21a is attached to the lower surface of the upper plate 7a so as to face each other. The lower surface of the lower side mold 21b is attached to the upper surface of the lower plate 7b so as to face each other. The outer peripheral surfaces of the sector mold 21c are attached to each segment 8 so as to face each other on the inner peripheral side thereof.

Each segment 8 is arranged in a ring shape around the central mechanism 4. That is, the annular center of each of the segments 8, the upper side mold 21a and the lower side mold 21b is the alternate long and short dash line CL. In FIGS. 1, 3 to 6, 8 the right half of many components 2, 3, 4, 5, 6, 7a, 7b, 8 and 9 of the vulcanizer 1 is shown, but the left half is also shown. It has substantially the same structure as the right half.

The outer peripheral surface of each segment 8 is inclined from the upper side to the lower side toward the outer peripheral side. The cylindrical container ring 2a is arranged around the central mechanism 4, and moves up and down on the outer peripheral side of each segment 8. The inner peripheral surface of the container ring 2a is inclined from the upper side to the lower side toward the outer peripheral side. The inner peripheral inclined surface of the container ring 2a and the outer peripheral inclined surface of each segment 8 are arranged so as to face each other.

The inner peripheral inclined surface of the container ring 2a and the outer peripheral inclined surface of each segment 8 are slidable. In this embodiment, each segment 8 is suspended from the upper plate 7a and the container ring 2a. The vertical movement plate 2, the container ring 2a, the hydraulic cylinder 3, the upper plate 7a, and the hydraulic cylinder 9. It functions as an opening / closing mechanism for opening / closing the mold 21.

The vulcanization medium pipe 10 supplies the heating medium M2 and the pressure medium M3 inside the vulcanization bladder 5. One end of the vulcanization medium pipe 10 is connected to the vulcanization medium supply source 11, and the other end is connected to the injection port 10a formed in the central post 4a. An on-off valve 12 is installed in the middle of the vulcanization medium pipe 10. The on-off valve 12 shuts off the vulcanization medium pipe 10 by closing the valve, and releases the vulcanization medium pipe 10 by opening the valve to allow communication.

As the heating medium M2, for example, steam or the like is used. As the pressurizing medium M3, for example, air, nitrogen gas, or the like is used. In this embodiment, the sources of the heating medium M2 and the pressurizing medium M3 are described as one vulcanization medium supply source 11, but they are actually separate sources.

The shaping pipe 13 supplies the shaping medium M1 to the inside of the vulcanization bladder 5. One end of the shaping pipe 13 is connected to the shaping medium supply source 14, and the other end is connected to the opening 13a formed in the central post 4a.

As the shaping medium M1, the above-mentioned pressure medium M3 can be used. However, the pressure of the shaping medium M1 is significantly lower than that of the pressure medium M3.

A piston portion 17 is inserted into the tank 15 arranged in the middle of the shaping pipe 13 so as to be movable up and down. The accommodation volume of the tank 15 is changed by moving the piston portion 17 up and down. The on-off valves 16a and 16b shut off the shaping pipe 13 by closing the valve, and release the shutoff of the shaping pipe 13 by opening the valve to communicate with each other.

The discharge pipe 18 discharges the mediums M (M1, M2, M3) inside the vulcanization bladder 5 to the outside. That is, the shaping medium M1, the heating medium M2, and the pressure medium M3 supplied inside the vulcanization bladder 5 are discharged to the outside of the vulcanization bladder 5. One end of the discharge pipe 18 extends to the outside of the vulcanizer 1 and opens, and the other end is connected to a discharge port 18a formed in the central post 4a. An on-off valve 18b is installed in the middle of the discharge pipe 18. The on-off valve 18 shuts off the discharge pipe 18 by closing the valve, and releases the shutoff of the discharge pipe 18 by opening the valve to communicate with the discharge pipe 18.

The pressure sensor 19 detects the internal pressure of the vulcanization bladder 5. The pressure detected by the pressure sensor 19 is sequentially input to the control unit 20. In this embodiment, the pressure sensor 19 is installed in the lower clamp portion 6, but the installation position of the pressure sensor 19 is not limited as long as the internal pressure of the vulcanization bladder 5 can be detected. The pressure sensor 19 can be optionally provided.

The control unit 20 controls the valve opening and closing operations of the on-off valves 12, 16a, 16b and 18b. Further, the control unit 20 controls the vertical movement of the piston unit 17 by a servomotor or the like to change the accommodation volume of the tank 15.

Next, an example of a procedure for vulcanizing the green tire G using the vulcanizing apparatus 1 will be described.

In order to vulcanize the green tire G, after the mold 21 is attached to the vulcanizer 1, the green tire G is arranged inside the widely opened mold 21 by using the loader 22 as illustrated in FIG. .. The upper clamp portion 6 is moved upward to increase the vertical separation distance between the clamp portions 6 and contract the vulcanization bladder 5. The green tire G is arranged on the lower side mold 21b in a sideways state by inserting the vulcanization bladder 5.

Next, as illustrated in FIG. 4, the upper clamp portion 6 is moved downward to shape the green tire G. In this shaping step, the on-off valves 16a and 16b are opened, and the shaping medium M1 is supplied from the shaping medium supply source 14 through the shaping pipe 13 to the inside of the vulcanization bladder 5 through the opening 13a. As a result, shaping pressure is applied to the vulcanization bladder 5 to expand it. The green tire G is held and shaped by the expanded vulcanization bladder 5. In the shaping step, it is preferable to move the piston portion 17 downward as much as possible. The other on-off valves 12 and 18b are closed. When the shaping step is completed, the on-off valve 16 is closed to stop the supply of the shaping medium M1 from the shaping medium supply source 14.

After the shaping step is completed, the mold 21 is closed and vulcanization is started. Therefore, as illustrated in FIG. 5, the upper side mold 21a is moved downward together with the upper plate 7a in the upper standby position, and the container ring 2a and each segment 8 are moved downward together with the vertically moving plate portion 2. As a result, each segment 8 is placed on the upper surface of the lower plate 7b so that the respective segments 8 are sandwiched between the upper and lower plates 7a and the lower plate 7b. In this state, as illustrated in FIG. 2, each segment 8 (sector mold 21c) is arranged at a position where the diameter is enlarged in a plan view.

Here, the downwardly moved upper side mold 21a abuts and presses against the upper side portion of the green tire G in the sideways state. As a result, the green tire G is in a state of being vertically sandwiched and pressed by the upper side mold 21a and the lower side mold 21b. Along with this, the vulcanization bladder 5 is also pressed from above and below, and the internal pressure rises and tries to bulge and deform outward in the radial direction. If nothing is done, the maximum outer diameter of the green tire G will increase, so a part of the shaping medium M1 inside the vulcanization bladder 5 is housed in the tank 5.

Specifically, after the shaping step is completed as described above, the on-off valve 16b arranged between the shaping medium supply source 14 and the tank 15 is closed, and the other on-off valve 16a is left open. .. Then, the piston portion 17 is moved upward to increase the accommodating volume of the tank 15, and the shaping medium M1 corresponding to the increased accommodating volume is moved from the inside of the vulcanization bladder 5 to the tank 15 through the shaping pipe 13. To accommodate. As a result, the increase in the internal pressure of the vulcanization bladder 5 due to the closing of the upper side mold 21a is suppressed, and the bulging deformation in which the maximum outer diameter of the green tire G is increased is suppressed accordingly.

In this embodiment, the operation of the piston portion 17 is controlled based on the detected internal pressure (internal pressure of the vulcanization bladder 5) detected by the pressure sensor 19. That is, even if the upper side portion of the green tire G is pressed by the downwardly moved upper side mold 21a, the internal pressure of the vulcanization bladder 5 after the shaping step is controlled based on this detected internal pressure. The portion 20 controls the piston portion 17 to move upward to increase the accommodating volume of the tank 15.

When the pressure sensor 19 is not provided, even if the upper side portion of the green tire G is pressed by the upper side mold 21a, the internal pressure of the vulcanization bladder 5 after the shaping step can be maintained constant in the tank 15. Preliminary tests and the like are performed for each specification of the tire to be vulcanized to grasp the increase in the accommodating volume in advance. Then, in the process of moving the upper side mold 21a downward to close the mold, the control unit 20 can control the piston unit 17 to move upward so as to secure an increase in the accommodating volume previously grasped.

As described above, the accommodation volume of the tank 15 can be increased without controlling the operation of the piston unit 17 by the control unit 20. Specifically, when the upper side portion of the green tire G is pressed by the upper side mold 21a and the internal pressure of the vulcanization bladder 5 is about to rise, the shaping medium M1 inside the vulcanization bladder 5 is naturally used. It flows into the inside of the tank 15 from the opening 13a through the shaping pipe 13. The piston portion 17 is moved upward by the shaping medium M1 that has flowed into the tank 15, and the accommodating volume of the tank 15 is increased. In this configuration, it is important to set the weight of the piston portion 17. Therefore, even if the upper side portion of the green tire G is pressed by the upper side mold 21a, an increase in the storage volume of the tank 15 capable of maintaining a constant internal pressure of the vulcanization bladder 5 after the shaping step is secured. The appropriate weight of the piston portion 17 that can be formed is grasped in advance by performing a preliminary test or the like.

After the downward movement of the upper side mold 21a is completed, the on-off valve 16a is closed. Further, the container ring 2a is further moved downward together with the vertical movement plate portion 2. As a result, the outer peripheral inclined surface of each segment 8 is pressed by the inner peripheral inclined surface of the container ring 2a that moves downward. As a result, as illustrated in FIGS. 6 and 7, each sector mold 21c moves close to the annular center CL, and these sector molds 21c are assembled in an annular shape to close the mold 21.

Next, the on-off valve 12 is opened, and the pressure media M2 and M3 are sequentially supplied from the vulcanization medium supply source 11 to the inside of the vulcanization bladder 5 from the injection port 10a through the vulcanization medium pipe 10. As a result, a high pressure is applied to the vulcanization bladder 5 to further expand the vulcanization bladder 5, and the inside of the green tire G is heated while being pressed by the vulcanization bladder 5 to vulcanize the green tire G. After a lapse of a predetermined vulcanization time, the tire in which the green tire G is vulcanized is completed.

After the vulcanization of the green tire G is completed, as illustrated in FIG. 8, the on-off valve 18b of the discharge pipe 18 is opened, and the medium M inside the vulcanization bladder 5 is added from the discharge port 18a through the discharge pipe 18. It is discharged to the outside of the vulcanization bladder 5. The other on-off valves 12, 16a and 16b are closed. Further, the mold 21 is opened, the vulcanization bladder 5 is contracted as illustrated in FIG. 3, and the completed tire is taken out from the vulcanization apparatus 1.

When the next green tire G is vulcanized by this vulcanizer 1, the same steps shown in FIGS. 1 to 8 are performed, but as illustrated in FIG. 8, the tank 15 is housed in the shaping after the shaping step. The medium M1 remains. Therefore, the shaping medium M1 housed in the tank 15 can be used for shaping the green tire G to be vulcanized next.

As described above, in the process of closing the mold 21 (21a), a part of the shaping medium M1 inside the vulcanization bladder 5 is accommodated in the tank 15 whose accommodating volume is increased by the piston portion 17. Since the bulging deformation that increases the maximum outer diameter of the green tire G is suppressed, the problem that the shaped green tire G is bitten by the closing mold 21 (21a) is prevented. As a result, tires of excellent quality are produced.

When a part of the shaping medium M1 inside the vulcanization bladder 5 is discharged to the outside of the vulcanization bladder 5, it is difficult to accurately control the discharge amount if it is released into the atmosphere. However, in the present invention, the movement adjustment of the shaping medium M1 is performed in a closed space in which the vulcanization bladder 5 and the tank 15 having variable accommodating volumes are connected by the shaping pipe 13. Therefore, this movement adjustment is more stable, which is advantageous for surely preventing the above-mentioned problems.

The present invention can be applied not only to the sectional type mold exemplified in the embodiment, but also to a so-called split mold. Further, the present invention can be applied not only when vulcanizing a green tire for a pneumatic tire but also when vulcanizing a green tire for various other types of tires.

1 Vulcanization device 2 Vertical movement plate 2a Container ring 3 Hydraulic cylinder 4 Central mechanism 4a Center post 5 Vulcanization bladder 6 Clamp 7a Upper plate 7b Lower plate 8 Segment 9 Hydraulic cylinder 10 Sulfurization medium piping 10a Injection port 10b On-off valve 11 Vulcanization medium supply source 12 On-off valve 13 Shaping pipe 13a Opening 14 Shaping medium supply source 15 Tank 16a, 16b On-off valve 17 Piston part 18 Discharge pipe 18a Discharge port 18b On-off valve 19 Pressure sensor 20 Control unit 21 Vulcanization Mold 21a Upper side mold 21b Lower side mold 21c Sector mold 22 Loader G Green tire M1 Shaping medium M2 Heating medium M3 Pressurizing medium

Claims (5)

An opening / closing mechanism of a vulcanization mold, a central mechanism having a vulcanization bladder, a vulcanization medium pipe for supplying a pressure medium and a heating medium inside the vulcanization bladder, and an inside of the vulcanization bladder. In a tire vulcanization apparatus provided with a shaping pipe for supplying a shaping medium to the outside and a discharge pipe for discharging the medium inside the vulcanization bladder to the outside.
A tank for accommodating the shaping medium at a position in the middle of the shaping pipe, an on-off valve for opening and closing the shaping pipe arranged at each position in front of and behind the tank of the shaping pipe, and a storage volume of the tank are changed. It has a piston unit and a control unit that controls the opening and closing of each of the on-off valves.
In the process of closing the vulcanization mold, the control unit controls the opening and closing of each of the on-off valves, so that the vulcanization is performed through the shaping pipe in the tank whose accommodating volume is increased by the piston unit. A tire vulcanizer characterized in that a part of the shaping medium inside the bladder is accommodated. The tire vulcanization apparatus according to claim 1, wherein the accommodation volume is increased by controlling the operation of the piston portion by the control unit in the process of closing the vulcanization mold. It has a pressure sensor that detects the internal pressure of the vulcanization bladder, and in the process of closing the vulcanization mold, the control unit operates the piston unit based on the magnitude of the internal pressure detected by the internal pressure sensor. The tire vulcanizer according to claim 2. The green tire is held by the vulcanization bladder that has been expanded by supplying a shaping medium to the inside of the vulcanization bladder to shape the green tire, and then the vulcanization mold is closed to close the vulcanization bladder. In the method of vulcanizing a tire in which a pressure medium and a heating medium are supplied to the inside of the tire and the inside of the green tire is pressed and heated by the vulcanization bladder.
A tank for accommodating the shaping medium is arranged inside the vulcanization bladder at a position in the middle of the shaping pipe for supplying the shaping medium, and a piston portion for changing the accommodating volume of the tank is provided. On-off valves for opening and closing the shaping pipe are arranged at the front and rear positions of the tank, and in the process of closing the vulcanization mold, the opening and closing of each on-off valve is controlled to control the opening and closing of the vulcanization bladder. By accommodating a part of the shaping medium inside the vulcanization medium into the tank whose accommodating volume is increased by the piston portion through the shaping pipe, the vulcanization bladder accompanying the closing of the vulcanization mold A tire vulcanization method characterized by suppressing an increase in internal pressure. The tire vulcanization method according to claim 4, wherein the shaping medium contained in the tank is used for shaping a green tire to be vulcanized next.

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