JP6809040B2 - Tire vulcanizer and method of manufacturing pneumatic tires using it - Google Patents

Description

The present invention relates to a tire vulcanizer and a method for manufacturing a pneumatic tire using the same. More specifically, the present invention relates to a tire vulcanizer capable of effectively reducing the temperature difference between the upper and lower sides in a bladder and a pneumatic tire using the same. Regarding the manufacturing method.

Generally, when vulcanizing a pneumatic tire, a heating medium and a pressure medium are supplied into a bladder inserted inside the unvulcanized tire to expand the bladder, and the unvulcanized tire is molded. Press toward. At this time, steam is used as the heating medium, and nitrogen gas is used as the pressurizing medium. However, when steam and nitrogen gas are used, the specific gravity of nitrogen gas is larger than that of steam, so in the expanded bladder, steam exists in a compressed state upward, and nitrogen gas exists below it. It will be in the state of Therefore, in the bladder during vulcanization, the temperature on the upper side becomes higher than that on the lower side, and a temperature difference between the upper and lower sides occurs. Tires that have been vulcanized in such a situation have a problem that the degree of vulcanization varies depending on the vertical direction during vulcanization.

In order to solve such a problem, various vulcanization methods and vulcanization devices have been proposed (see, for example, Patent Documents 1 and 2). In Patent Document 1, a supply port for supplying the heating medium and the pressure medium into the bladder and a recovery port for collecting the heating medium and the pressure medium in the bladder are provided, and the heating medium and the pressure medium are provided during vulcanization. It has been proposed to circulate these media so that they are maintained at a predetermined temperature and pressure and that these media are agitated in the bladder to reduce the temperature difference between the top and bottom in the bladder. .. Further, in Patent Document 2, a stirring blade is installed in the bladder, and by rotating the stirring blade, steam and nitrogen gas in the bladder are stirred and mixed to reduce the temperature difference between the upper and lower sides in the bladder. Proposed.

However, in the former proposal, since the heating medium and the pressure medium continue to circulate during vulcanization, there is a problem that energy loss is large and the heating medium and the pressure medium cannot always be sufficiently agitated in the bladder. .. Further, in the latter proposal, a stirring blade must be newly installed in the bladder, and there is a problem that the vulcanization equipment becomes complicated accordingly. Therefore, further measures have been required to effectively reduce the temperature difference between the upper and lower sides in the bladder with a simple structure.

JP-A-2015-223777 JP-A-2009-029035

An object of the present invention is to provide a tire vulcanizer capable of effectively reducing the vertical temperature difference in a bladder and a method for manufacturing a pneumatic tire using the tire vulcanizer.

The tire smelting apparatus of the present invention for achieving the above object grips a mold for forming the outer surface of a pneumatic tire, a tubular bladder inserted inside the pneumatic tire, and both ends of the bladder. A central mechanism for operating the bladder with a pair of clamps, a medium supply means for supplying a heating medium and a pressurizing medium into the bladder, and the heating medium and the pressurizing medium supplied into the bladder. A tire smelting apparatus including a stirring means for injecting a stirring medium for stirring a medium into the bladder, wherein the medium supply means supplies the heating medium and the pressurizing medium into the bladder. To the injection port and the injection port for the stirring means to inject the stirring medium into the bladder, including a supply port for the purpose and a supply path for guiding the heating medium and the pressurizing medium to the supply port. and a flow path for guiding the stirring medium, the supply port and the injection port and is provided separately, and the supply passage and said passage has a separate system der is, is injected from the injection port It is characterized in that the flow velocity of the stirring medium is larger than the flow velocity of the heating medium and the pressurizing medium supplied from the supply port .

In the present invention, as described above, the heating medium and the pressurizing medium supplied into the bladder are agitated by the agitation medium jetted by the stirring means, so that the temperature difference between the upper and lower sides in the bladder is effectively reduced. Can be done. At this time, since the heating medium and the pressure medium are agitated by injecting the agitation medium, it is not necessary to newly install a complicated mechanism for agitation. Further, since the stirring medium is injected in a system separate from the supply of the heating medium and the pressurizing medium, the stirring medium can be sprayed in the required amount at the required time, and the efficiency is improved while avoiding energy loss. It is possible to reduce the temperature difference between the top and bottom of the bladder.

In the present invention, as described above, the flow velocity of the stirring medium injected from the injection port is larger than the flow velocity of the heating medium and the pressurizing medium supplied from the supply port. In addition to this, the specifications may be such that the opening diameter of the injection port is smaller than the opening diameter of the supply port . As a result , the heating medium and the pressurizing medium in the bladder can be effectively agitated, which is advantageous in reducing the temperature difference between the upper and lower sides in the bladder.

In the present invention, the specification may be such that the injection port faces the bottom of the bladder. Alternatively, the specification may be such that the injection port is arranged at the bottom of the bladder and the flow path is composed of a hose that can be deformed together with the bladder. In these specifications, since the specific gravity is relatively large, the stirring medium can be reliably injected onto the pressure medium settled on the bottom of the bladder, and the heating medium and the pressure medium in the bladder are agitated to move up and down in the bladder. It is advantageous to reduce the temperature difference.

In the method for producing a pneumatic tire using the tire vulcanizer of the present invention, after the heating medium and the pressurizing medium are supplied into the bladder by the medium supply means, when the pressure in the bladder drops, the inside of the bladder is used by the stirring means. It is preferable to inject a stirring medium into the bladder to stir the heating medium and the pressure medium in the bladder and pressurize the inside of the bladder.

It is sectional drawing which shows an example of the tire vulcanizing apparatus which comprises embodiment of this invention. It is sectional drawing which shows an example of the tire vulcanization apparatus which comprises another Embodiment in this invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

The tire vulcanizer of the present invention shown in FIG. 1 has a mold 10 for forming the outer surface of the pneumatic tire T, a tubular bladder 20 inserted inside the pneumatic tire T, and a center for operating the bladder 20. The mechanism 30, the medium supply means 40 for supplying the heating medium and the pressurizing medium inside the bladder 10, and the stirring medium for stirring the heating medium and the pressurizing medium supplied in the bladder 10 are bladder. It is provided with a stirring means 50 for injecting into the inside of the 10. Although omitted in FIG. 1, a heating means for heating the mold 10 from the outside is also provided.

The mold 10 includes a lower bead ring 11 and an upper bead ring 12 for forming the bead portion of the pneumatic tire T, and a lower side plate 13 and an upper side plate for forming the sidewall portion of the pneumatic tire T. It is composed of 14 and a plurality of sectors 15 for forming the tread portion of the pneumatic tire T, and the tire T is vulcanized inside the mold 10. In the present invention, the structure of the mold 10 is not particularly limited, and in addition to the sectional type mold as shown in the figure, for example, a split type mold can be used.

In the bladder 20, the lower end of the vulcanizer is gripped between the lower bead ring 11 and the lower clamp ring 31 provided in the central mechanism 30 described later, and the upper end of the vulcanizer is the central mechanism 30 described later. It is gripped between the upper clamp ring 32a and the auxiliary ring 32b provided in the above. In the vulcanized state shown in FIG. 1, the bladder 20 is in a state of being expanded radially outward of the tire T, but when the tire T is taken out from the vulcanization apparatus after vulcanization, the upper clamp ring 32b (and the auxiliary ring) are used. 32b) moves upward, and the bladder 10 is pulled out from the inside of the tire T accordingly.

As described above, the central mechanism 30 has a lower clamp ring 31 that grips the lower end portion of the bladder 20 and an upper clamp ring 32a and an auxiliary ring 32b that grip the upper end portion as a pair of clamps that grip both ends of the bladder 20. To be equipped. The lower clamp ring 31 is arranged so as to be connected to the lower bead ring 11 of the mold 10 and is fixed to the cylinder 33. The cylinder 33 is arranged around the center post 33 arranged at the center position of the pneumatic tire T, and includes a medium supply means 40 and a stirring means 50 described later. Further, a drainage channel (not shown) for discharging the heating medium and the pressurized medium from the inside of the bladder 20 after vulcanization and a drainage channel (not shown) for discharging the condensed liquid of the heating medium (steam) shall be provided. You can also. The upper clamp ring 32a is fixed to the upper part of the center post 34. The auxiliary ring 32b is attached to the upper clamp ring 32a when gripping the bladder 20, and is arranged so as to be connected to the upper bead ring 12 of the mold 10. The center post 34 is arranged at the center position of the pneumatic tire T as described above, but is configured to be vertically movable, and the movement of the upper clamp ring 32a when the above-mentioned tire T is taken out by this elevation. Is possible.

The medium supply means 40 includes a supply port 41 for supplying the heating medium and the pressurizing medium into the bladder 20, and a supply path 42 for guiding the heating medium and the pressurizing medium from the supply source (not shown) to the supply port 41. And include. As the heating medium, for example, steam, nitrogen gas or the like is used, and as the pressurizing medium, for example, nitrogen gas, air deoxygenated by combustion or the like is used. An operation mechanism such as a valve for adjusting the flow rate and the flow velocity of the heating medium and the pressurizing medium may be provided in the middle of the supply path 42. In the illustrated example, as described above, the cylinder 33 is provided with the medium supply means 40, the supply port 41 is opened on the surface of the cylinder 33, and the supply path 42 is formed inside the cylinder 33.

The stirring means 50 includes an injection port 51 for injecting the stirring medium into the bladder 20, and a flow path 52 for guiding the stirring medium from the supply source (not shown) to the injection port 51. As the stirring medium, for example, steam, nitrogen gas or the like is used. An operation mechanism such as a valve for adjusting the flow rate or the flow velocity of the stirring medium may be provided in the middle of the flow path 52. In the illustrated example, as described above, the cylinder 33 is provided with the stirring means 50, the injection port 51 is arranged at the tip of the nozzle 33a protruding from the surface of the cylinder 33, and the flow path 52 is the cylinder 33 and the nozzle 33a. It is formed inside the. When the nozzles 33a are used as shown in the drawing, it is preferable to provide about 1 to 10 nozzles on the circumference of the cylinder for efficient stirring. The arrow extending from the injection port 51 in the figure indicates the injection (injection direction) of the stirring medium.

In the present invention, the medium supply means 40 and the stirring means 50 are separate systems. Specifically, as shown in FIG. 1, the supply port 41 and the injection port 51 are provided separately, and the supply path 42 and the flow path 552 are configured to be different paths without overlapping. Although not shown in the figure, the above-mentioned operation mechanism such as a valve is also provided in each path (supply path 42, flow path 52), and the flow rate and flow velocity of each medium can be adjusted separately. It has become. Since the heating medium and the medium that can be used as the stirring medium are common as described above, a common medium (for example, steam) is adopted, and the heating medium and the stirring medium are supplied from the same source. Although it may be obtained, even in this case, the path (supply path 42, flow path 52) for guiding each medium into the bladder 20 and the operation mechanism for adjusting the flow rate and flow velocity of each medium are It is necessary to have a separate system.

In the tire vulcanizer of the present invention described above, since the heating medium and the pressure medium supplied in the bladder 20 can be agitated by the agitation medium jetted by the agitating means 50, this tire vulcanizer is used. As a result, the difference in temperature between the upper and lower sides of the bladder 20 can be effectively reduced. At this time, since the heating medium and the pressure medium are agitated by injecting the agitation medium, it is not necessary to newly install a complicated mechanism for agitation. Furthermore, since the injection of the stirring medium is performed in a system separate from the supply of the heating medium and the pressure medium, it is not affected by other intake / exhaust operations in the vulcanization process, and it is necessary to minimize it when necessary. The stirring medium can be sprayed in an amount. Therefore, it is possible to efficiently reduce the vertical temperature difference in the bladder 20 while avoiding energy loss.

In order to effectively stir the heating medium and the pressurizing medium in the bladder 20, it is effective to vigorously inject the stirring medium by the stirring means 50. Therefore, it is preferable that the opening diameter of the injection port 51 is smaller than the opening diameter of the supply port 41 of the medium supply means 40. Further, the pressure and flow rate of the stirring medium are adjusted by an operation mechanism such as a valve provided in the flow path 52, and the flow velocity of the stirring medium injected from the injection port 51 is supplied from the supply port 41 and the heating medium. It is preferable to make it larger than the flow velocity of the pressurizing medium.

In the bladder 20 during vulcanization, the pressurizing medium (nitrogen gas) having a relatively large specific gravity settles on the bottom of the bladder due to the difference in specific gravity between the heating medium and the pressurizing medium, and the heating medium (steam) is generated. The drain that has changed to liquid (water) tends to settle at the bottom of the bladder. Therefore, it is preferable that the stirring medium is sprayed toward the pressurizing medium or drain that has settled on the bottom of the bladder. That is, as shown in FIG. 1, it is preferable that the injection port 51 is directed to the bottom of the bladder 20. Alternatively, as illustrated in FIG. 2, the flow path 52 may be extended to the bottom of the bladder 20 so that the injection port 51 is arranged at the bottom of the bladder 20. In this case, the flow path 52 may be formed of, for example, a hose 53 that can be deformed together with the bladder 20 so that the flow path 52 can follow the deformation of the bladder 20 in the vulcanization step. When steam is sprayed as a stirring medium toward the drain that has settled on the bottom of the bladder as described above, not only the drain and the surrounding medium are stirred, but also gas-liquid contact is promoted, and the drain itself is leveled. There is also an advantage that heat exchange (heating of the drain) from the heating medium (steam) to the drain can be promoted.

When the injection port 51 is directed to the bottom of the bladder 20, not only the aim is simply aimed at the bottom of the bladder 20, but also a flow is formed such that the drain swirls along the circumferential direction of the bladder 20 at the bottom of the bladder 20, for example. As such, the direction of the injection port 51 may be adjusted. For example, when the nozzle 33a is used as in the example of FIG. 1, the nozzle 33a is tilted with respect to the radial direction of the bladder 20, and the stirring medium is tilted in one direction inclined with respect to the radial direction of the bladder 20. Can be sprayed.

As described above, the opening diameter of the injection port 51 is preferably smaller than the opening diameter of the supply port 41 of the medium supply means 40, but in particular, the opening area of each injection port 51 is the total area of the supply port 41. For example, it is preferably 3% to 20%. By making the opening area of each injection port 51 sufficiently small in this way, it becomes advantageous to vigorously inject the stirring medium, and the heating medium and the pressurizing medium in the bladder 20 can be efficiently stirred. it can.

When manufacturing a pneumatic tire using the above-mentioned tire vulcanizing apparatus, first, an unvulcanized pneumatic tire T is introduced into the mold 10, and a bladder 20 is inserted inside the pneumatic tire T. Then, the heating medium and the pressure medium are introduced into the bladder 20 by the medium supply means 40, and the mold 10 is heated to vulcanize the pneumatic tire T. At this time, in the illustrated example, the heating medium and the pressurizing medium are supplied from the supply source of each medium through the supply path 42 into the bladder 20 from the supply port 41, but a predetermined amount of the heating medium and the pressurizing medium are introduced. After that, the supply port 41 or the supply path 42 is closed by an operating mechanism such as a valve, and the supply of the heating medium and the pressurizing medium is stopped.

On the other hand, the injection port 51 or the flow path 52 of the stirring means 50 is closed by an operating mechanism such as a valve when vulcanization is started, but when the internal pressure of the bladder 20 drops during vulcanization, the stirring means The injection port 51 or the flow path 52 of the 50 is opened, and the inside of the bladder 20 is stirred by the stirring means 50. That is, the stirring medium supplied from the supply source through the flow path 52 is injected from the injection port 51 toward the inside of the bladder 20. The heating medium and the pressurizing medium in the bladder 20 are agitated by the injection of the agitation medium, and the inside of the bladder 20 is pressurized by adding the agitation medium. At this time, the stirring medium may be continuously injected once until the internal pressure of the bladder 20 is restored to a desired pressure, or may be intermittently injected a plurality of times. The subsequent steps can be performed in the same manner as usual, the mold 10 is opened, the bladder 20 is peeled off from the inner surface of the pneumatic tire T, and the pneumatic tire T is taken out from the vulcanizer and added. The vulcanization process is complete.

When a pneumatic tire is manufactured by using the above-mentioned tire vulcanizer as described above, vulcanization can be performed in a state where the temperature difference between the upper and lower sides in the bladder 20 is reduced by injecting a stirring medium. It is possible to improve the quality of pneumatic tires. Further, after the heating medium and the pressurizing medium are introduced at the beginning of the vulcanization step, the supply of the heating medium and the pressurizing medium can be stopped, and when the internal pressure of the bladder 20 drops during vulcanization, it is used for stirring. Since it is dealt with by injecting the medium, the amount of each medium used can be suppressed and energy loss can be avoided.

A conventional tire vulcanizer (conventional example 1) not provided with a mechanism for stirring the medium in the bladder, and a tire vulcanization provided with a circulation mechanism of a heating medium and a pressure medium for stirring the medium in the bladder. The device (Comparative Example 1), the tire vulcanizer of the present invention provided with the stirring means of FIG. 1 (Example 1), and the tire vulcanizing device of the present invention provided with the stirring means of FIG. 2 (Example 2). The pneumatic tire was vulcanized 10 times according to each of the above. Measure the temperature inside the bladder during vulcanization (the temperature at the bottom of the bladder and the temperature at the top of the bladder) in each tire vulcanizer, determine the temperature difference between the top and bottom of the bladder, and check for heat loss due to disposal of the heat medium. These are also shown in Table 1.

As is clear from Table 1, when vulcanization was performed by the tire vulcanization apparatus of Examples 1 and 2, the temperature difference between the upper and lower sides could be reduced without causing heat loss. On the other hand, when the heating medium and the pressure medium are circulated as in Comparative Example 1, the heat loss due to the circulation of each medium is large, and the temperature difference between the upper and lower sides in the bladder can be reduced, but vulcanization is performed 10 times. There was a large variation in the degree of reduction in the above, and it was not possible to stably eliminate the temperature difference between the top and bottom.

10 Mold 11 Lower bead ring 12 Upper bead ring 13 Lower side plate 14 Upper side plate 15 Sector 20 Bladder 30 Central mechanism 31 Lower clamp ring 32a Upper clamp ring 32b Auxiliary ring 33 Cylinder 33a Nozzle 34 Center post 40 Medium supply means 41 Supply port 42 Supply path 50 Stirring means 51 Injection port 52 Flow path T Pneumatic tire

Claims (6)

A mold that forms the outer surface of the pneumatic tire, a tubular bladder that is inserted inside the pneumatic tire, and a central mechanism that operates the bladder with a pair of clamps that grip both ends of the bladder. A medium supply means for supplying the heating medium and the pressurizing medium into the bladder and a stirring medium for stirring the heating medium and the pressurizing medium supplied into the bladder are injected into the bladder. A tire vulcanizer equipped with agitating means
The medium supply means includes a supply port for supplying the heating medium and the pressurizing medium into the bladder, and a supply path for guiding the heating medium and the pressurizing medium to the supply port, and the stirring means. Includes an injection port for injecting the stirring medium into the bladder and a flow path for guiding the stirring medium to the injection port, and the supply port and the injection port are separately provided and said. Ri said flow path and a separate lineage der the supply passage, the flow speed of the stirring medium ejected from the injection port is greater than the flow rate of the heating medium and the pressurizing medium is supplied from the supply port A featured tire smelter. The tire vulcanizer according to claim 1, wherein the opening diameter of the injection port is smaller than the opening diameter of the supply port. The tire vulcanizer according to claim 1 or 2 , wherein the injection port faces the bottom of the bladder. The tire vulcanizer according to claim 1 or 2 , wherein the injection port is arranged at the bottom of the bladder, and the flow path is composed of a hose that can be deformed together with the bladder. The method for manufacturing a pneumatic tire using the tire vulcanizer according to any one of claims 1 to 4 , after supplying the heating medium and the pressurizing medium into the bladder by the medium supply means. When the pressure in the bladder decreases, the stirring medium is sprayed into the bladder by the stirring means to stir the heating medium and the pressurizing medium in the bladder and pressurize the inside of the bladder. A method of manufacturing a pneumatic tire characterized by. A mold that forms the outer surface of the pneumatic tire, a tubular bladder that is inserted inside the pneumatic tire, and a central mechanism that operates the bladder with a pair of clamps that grip both ends of the bladder. A medium supply means for supplying the heating medium and the pressurizing medium into the bladder and a stirring medium for stirring the heating medium and the pressurizing medium supplied into the bladder are injected into the bladder. A method for manufacturing a pneumatic tire using a tire vulcanizer equipped with a stirring means.
The medium supply means includes a supply port for supplying the heating medium and the pressurizing medium into the bladder, and a supply path for guiding the heating medium and the pressurizing medium to the supply port, and the stirring means. Includes an injection port for injecting the stirring medium into the bladder and a flow path for guiding the stirring medium to the injection port, and the supply port and the injection port are separately provided and said. The supply path and the flow path are separate systems,
After supplying the heating medium and the pressurizing medium into the bladder by the medium supply means, when the pressure in the bladder drops, the stirring medium injects the stirring medium into the bladder by the stirring means. A method for producing a pneumatic tire, which comprises stirring the heating medium and the pressurizing medium in the bladder and pressurizing the inside of the bladder.

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