JP2008195058A - Tire vulcanizer and vulcanizing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To vulcanize and mold a raw tire by heating uniformly with a low heat loss. <P>SOLUTION: This vulcanizer 1 for hot air heating the inner surface of a tire T is equipped with: a main mechanism having a vulcanizing mold 10 to hold the raw tire T, an air blower 40, a heater 42, and inner and outer double pipes 22a, 22b serving as supply/exhaust channels of hot air to heat the raw tire; a blocking plate 44 to open or close the channel of hot air between the main mechanism and the vulcanizing mold 10; a notch 25 formed at the inner pipe 22b of the double pipe to form a circulation passage of hot air when the channel is blocked; and a cylindrical pipe 24 to open or close the notch 25. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a tire vulcanizer and a vulcanization method for vulcanizing an unvulcanized tire molded on a rigid core in a tire vulcanization process.

As a method of vulcanizing and forming a raw tire into a tire, a bladder vulcanization method in which the inner surface of the tire is heated and vulcanized via a bladder, and each member constituting the raw tire is directly molded on a metal rigid core In addition, there is a core vulcanization method (for example, see Patent Document 1) in which a raw tire is vulcanized together with a rigid core.
In this core vulcanization method, first, a tire constituting a tire such as a carcass ply, a belt, and a tread rubber is sequentially pasted or wound on a rigid core serving as an inner mold, thereby forming a green tire. The rigid core on which the green tire is formed is set in the outer mold, and the rigid core is heated to thermally expand the green tire.
When heating a rigid core (inner mold) with this core vulcanization method, it is difficult to use steam or hot water as a heating medium for reasons such as rust, drain, and sealing properties. A method of blowing and heating is employed.

  By the way, the specific heat of gas is much smaller than the specific heat of steam and the specific heat of hot water, and the heat exchange efficiency between hot air and a rigid core (inner mold) that is a metal material (for example, aluminum-based alloy casting) is low. It takes time to heat up the core. Therefore, it is desirable that the amount of hot air supplied into the rigid core is as large as possible. Therefore, it is desirable to supply hot air into the tire through a pipe having a diameter as large as possible, that is, a pipe having a diameter close to the bead diameter of the tire.

FIG. 8A is a cross-sectional view of an essential part showing a preferable air blowing structure in a vulcanizer employing a core vulcanization method.
The vulcanizing mold 10 of the vulcanizer 1 includes a tread forming mold 12 constituting an outer mold, and upper and lower side molds 14 disposed inside the tread forming mold 12 in the figure. 16, the tread forming mold 12 and a rigid core (inner mold) 18 disposed in a recess formed by the upper and lower side molds 14 and 16, each of these molds The raw tire T is vulcanized and molded inside.

Each of the molds 12, 14, 16, and 18 is made of a rigid body such as an aluminum base material or an iron base material, and the tread forming mold 12 forms the outer surface shape of the tread portion of the tire T on the inner surface thereof. It has a molding surface for forming a large number of segments that can move inward and outward in the radial direction, and these segments form a ring as a whole.
The upper and lower side molds 14, 16 have an annular shape and have a forming surface for forming the outer surface shape of the sidewall portion of the tire T. At least one of the upper and lower side molds 14, 16 is a cavity. It is configured to be movable in the mold opening direction so that the raw tire T can be inserted and the vulcanized tire T can be taken out.
The rigid core (inner mold) 18 has a hollow ring shape, and its outer peripheral surface is a molding surface for forming the inner surface shape of the tire T.

A large-diameter duct (or a ventilation pipe) 20 close to the bead diameter of the tire T is attached to a space 17 in the center of the annular upper and lower side molds 14 and 16, and the hollow annular rigid core 18 is formed. A disc-shaped partition plate 15 is arranged in the center in the vertical direction inside.
Here, when the partition plate 15 is attached to the inside of the rigid core 18, a gap 15 a through which hot air flows is formed between the outer periphery of the partition plate 15 and the inner periphery of the rigid core 18. The outer diameter is smaller than the inner diameter of the rigid core 18. As a result, the partition plate 15 forms a flow path for the hot air to flow along the inner surface of the rigid core 18.

Therefore, the heated gas supplied from the lower air supply duct 20a passes along the inside of the partition plate 15 and the rigid core 18 as indicated by the arrow through the gap 15a between the partition plate 15 and the rigid core 18. The air is exhausted to the upper exhaust duct 20b.
In this configuration, since the large diameter air supply / exhaust duct 20 (20a, 20b) substantially equal to the bead diameter of the tire T is used, the efficiency of heat exchange is good. However, on the other hand, in this configuration, the exhaust duct 20b also extends upward. For example, if the configuration in which the upper side mold is raised is used, there is a problem that the apparatus becomes large.

FIG. 8B is a cross-sectional view of an essential part showing another preferable air blowing structure in a vulcanizer adopting a core vulcanization method.
As shown in FIG. 8B, the vulcanization mold 10 of the vulcanizer 1 has a duct 22 with a double pipe structure of an outer air supply duct 22a and an inner exhaust duct 22b, and an upper end portion of the inner exhaust duct 22b. The structure extends to the inside of the vulcanization mold 10 and reaches the partition plate 15 attached in the rigid core 18, and the heated gas blown from the outer duct 22a is sent to the inner duct 22b as shown by the arrow. A structure that exhausts air from is used.

However, in this conventional vulcanizer, when the green tire T molded on the core 18 is placed on the vulcanizer 1, the hot air comes into contact with the outside air, so that the temperature decreases and the If the vulcanization is started after closing the), there is a problem that the temperature at the initial stage of vulcanization is lowered and the target temperature cannot be achieved.
In addition, since the hot air does not circulate, it is difficult to maintain a uniform temperature, and the variation in heating in the tire circumferential direction increases, and there is a concern that the physical properties of the vulcanized rubber may fluctuate in the tire circumferential direction and the tire quality may deteriorate.
This problem cannot be solved by stopping the supply of hot air before setting the raw tire and supplying hot air after placing the raw tire.

In the core vulcanization method, it is necessary to pass a heat source (hot air) through the rigid core in order to supply heat to the tire inner surface.
However, since the rigid core is integrated with the green tire before and after vulcanization, when the raw tire is set in the vulcanizer or when the tire is removed from the vulcanizer after vulcanization, the hot air supplied as it is Because it is released to the outside air, the amount of heat is lost, and the temperature of the flow path for supplying hot air and hot air decreases, so the initial hot air temperature during the next raw tire vulcanization decreases, and the hot air in the tire circumferential direction decreases. There arises a problem that the supply temperature varies.

On the other hand, when the tire is set in the vulcanizer or taken out after vulcanization, it is conceivable to stop supplying hot air, but once the hot air supply is stopped, the raw tire is set and vulcanized. Since the initial temperature of the hot air when resuming is reduced, the problem cannot be solved. In addition, since hot air is heated by a heater, there is a problem that the temperature is not stabilized unless it is circulated through the heater.
JP 2006-26915 A

  The present invention has been made to solve the above-mentioned problems in the conventional core vulcanization method, and its purpose is to reduce the hot air temperature due to heat loss when hot air vulcanization is performed on a raw tire by the core vulcanization method. It is to eliminate the decrease, to uniformly heat each part of the raw tire, and to reduce the size of the vulcanizer.

According to the first aspect of the present invention, there is provided a vulcanizer for heating a tire inner surface with hot air, a vulcanization mold for accommodating a raw tire, a raw tire heating medium feeding means, a heater, and a heating medium supply / exhaust flow A central mechanism having an inner / outer double pipe as a path, a blocking means for blocking a flow path of hot air between the central mechanism and the vulcanization mold, and hot air when the blocking means blocks the flow path And a circulation path that circulates in the double pipe.
According to a second aspect of the present invention, in the tire vulcanizer according to the first aspect, the green tire is formed on a rigid core, and the rigid core constitutes an inner mold of the vulcanization mold. It is characterized by doing.
According to a third aspect of the present invention, in the tire vulcanizer according to the second aspect, a partition plate that forms a flow passage through which the raw tire heating medium flows along the inner surface of the rigid core is disposed in the rigid core. It is characterized by.
According to a fourth aspect of the present invention, in the tire vulcanizer according to any one of the first to third aspects, the blocking means for blocking the flow path of the heating medium between the central mechanism and the vulcanization mold is the flow It is a blocking plate that can move forward and backward with respect to the road.
According to a fifth aspect of the present invention, in the tire vulcanizer according to any one of the first to fourth aspects, the hot air flow path between the central mechanism and the vulcanization mold is blocked by being provided in the inner pipe. And a means for closing the notch to form the circulation path of the heating medium.
According to a sixth aspect of the present invention, in the tire vulcanizer according to the fifth aspect, the means for closing the notch is a cylindrical tube movable along the peripheral surface of the inner tube.
A seventh aspect of the present invention is the tire vulcanizer according to any one of the first to fourth aspects, wherein the central mechanism is brought into contact with the blocking means and the heating medium between the central mechanism and the vulcanizing mold is used. It has a means to move between the 1st position which interrupts | blocks this flow path, and the 2nd position which connects the said inner and outer double pipes with the said flow path of the said rigid core, It is characterized by the above-mentioned.
According to an eighth aspect of the present invention, in the tire vulcanizer according to any one of the first to seventh aspects, the heater is disposed inside the inner pipe, and the heating medium feeding means is the inner portion. It is arranged at the end of the tube.
The invention of claim 9 is a raw tire vulcanizing method in a vulcanizer comprising a central mechanism having a blower, a heater, a flow path for supplying and exhausting a raw tire heating medium and inner and outer double pipes, A preheating step of circulating the heating medium only in a central mechanism while heating, a step of storing a raw tire formed on a rigid core in a vulcanization mold, and the heating medium inside the rigid core and the And heating the green tire by circulating it in the central mechanism.

(Function)
(1) About no loss of heat According to the present invention, each member constituting the green tire is directly molded on a metal rigid core, and then accommodated in a vulcanization mold in that state, and hot air is cored. The air is blown inside, and the raw tire inner surface is heated and vulcanized.
When a raw tire molded on a rigid core is placed on a vulcanizer, if there is contact between preheated hot air and outside air, heat for heating the tire is lost and the hot air temperature is lowered. Therefore, in the preheating stage until the tire is mounted on the vulcanizer, the hot air is circulated only in the central mechanism through the notch provided in the inner pipe while blocking the contact between the hot air and the outside air by the blocking plate. Keep the hot air temperature uniform.
After the tire is mounted on the vulcanizer, the flow path is changed by pulling out the blocking plate and raising the cylindrical tube that closes the notch of the inner tube, and hot air is sent inside the rigid core.
Thereby, there is no loss of heat, and hot air at a stable temperature can be used for tire heating.
(2) About giving heat equally to a tire In hot air circulation, the structure which incorporated the air blower located in the same central axis as the central axis of a tire is employ | adopted.
With this configuration, a uniform amount of hot air can be supplied in the tire circumferential direction.
(3) About the compactness of the vulcanizer Since it has a built-in blower and the circulation flow path during preheating and vulcanization is completed inside the double pipe, it is extremely compact and does not take up much space.

  According to the present invention, in hot air vulcanization by the core vulcanization method, (1) there is no heat loss (decrease in hot air temperature), (2) heat can be evenly applied to the tire, and (3) The vulcanizer can be made compact.

(First embodiment)
A tire vulcanizer and a vulcanization method according to a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a main part showing a vulcanization standby state of a vulcanizer according to a first embodiment of the present invention, and FIG. 2 is a longitudinal sectional view of the vulcanizer during vulcanization. .
About the vulcanizer 1 of illustration, the same number is attached | subjected to the location same as the vulcanizer 1 already demonstrated. That is, the mold 10 of the vulcanizer 1 includes a tread forming mold 12 constituting an outer mold, and upper and lower side molds 14 and 16 disposed above and below the tread forming mold 12. It is composed of a core (inner mold) 18.

The molds 12, 14, 16, and 18 have the same materials and configurations as those already described.
A large-diameter duct (vent pipe) 22 close to the bead diameter of the tire T constituting the central mechanism of the vulcanizer is attached to the central space 17 of the upper and lower side molds 14 and 16. This duct 22 is formed in a double structure consisting of an outer duct 22a and an inner duct 22b that is smaller in diameter and arranged concentrically with the outer duct 22a, as shown in FIG. 8B. The upper end of the inner duct 22b is fixed to the rigid core 18 when the rigid core 18 is disposed in the space 17, and forms a partition plate 15 (forming a hot air flow path as a heating medium in the rigid core 18). (See FIG. 2).
As described above, when the partition plate 15 is disposed inside the rigid core 18, a gap 15 a through which hot air flows is formed between the outer periphery and the inner periphery of the rigid core 18. Moreover, the outer diameter is formed smaller than the inner diameter of the rigid core 18.

In order to supply hot air from the inner duct 22b to the outer duct 22a and forcibly circulate the hot air through the inner and outer ducts 22b and 22a, a blower 40 as a heating medium feeding means is disposed at the lower end of the inner duct 22b. Has been.
Further, a heater 42 is disposed in the inner duct 22b, and the hot air forcedly circulated by the blower 40 is heated by the heater 42 when passing through the inner duct 22b.
Further, the connecting portion between the outer duct 22a and the lower side mold 16 of the vulcanizing mold 10 corresponds to the blocking means of the present invention for blocking the flow of hot air between the duct 22 and the vulcanizing mold 10. The blocking plate 44 is disposed so as to be pulled out (that is, slidable left and right in the drawing) by a driving mechanism (not shown).

  The inner duct 22b is provided with a notch 25 below the blocking plate 44 at an appropriate interval on the peripheral wall. The notch 25 is configured so that hot air, which is sent to the outer duct 22 a by the blower 40 when the blocking plate 44 blocks the flow of hot air between the duct 22 and the opening of the lower side mold 16, passes through the notch 25. A circulation path in which hot air is forcedly circulated between the inner and outer ducts 22b and 22a is formed.

  A cylindrical tube 24 corresponding to the means for closing the notch of the present invention is fitted to the outer periphery of the inner duct 22b, and this cylindrical tube 24 moves up and down along the outer periphery of the inner duct 22b by a drive mechanism (not shown). In the raised position (FIG. 2), the circulation of the hot air passing through the notch 25 is interrupted and the notch 25 is covered in the lowered position (FIG. 1). It is exposed so that hot air can flow between the inner and outer ducts 22b and 22a.

Next, operation | movement of the tire vulcanizer 1 which concerns on this embodiment is demonstrated with reference to FIG.1 and FIG.2.
FIG. 1 shows a state where the blocking plate 44 blocks the duct 22 and the central space 17 of the vulcanizing mold 10, and FIG. 2 shows a state where the blocking plate 44 blocks the duct 22 and the central space 17 of the vulcanizing mold 10. And shows a state of opening.

In the vulcanizer 1 during the preheating standby shown in FIG. 1, the blocking plate 44 is operated to block between the duct 22 and the central space 17 of the lower side mold 16. At the same time, the cylindrical tube 24 is lowered to expose the notch 25 of the inner duct 22b.
In this state, the hot air heated by the heater 42 in the inner duct 22b is pumped to the outer duct 22a by the blower 40, but the flow into the vulcanizing mold 10 is blocked by the blocking plate 44. It flows into the inner duct 22b through the notch 25, is heated by the heater 42, and is pumped again into the outer duct 22a by the blower 40.
Thus, the hot air is forcibly circulated only in the central mechanism, that is, between the inner and outer ducts 22b and 22a, and does not come into contact with the outside air, so the temperature of the hot air sent to the outer duct 22a is always a stable and constant temperature. Maintained.

Next, the tread forming mold 12 is opened radially outward from the state of FIG. 1, and the upper side mold 14 is raised, and the raw tire T formed on the rigid core 18 is moved to the lower side mold 16. Place on top.
When the green tire T is placed on the lower side mold 16, the tread forming mold 12 is closed inward, the upper side mold 14 is lowered, and the tread forming mold 12 and the upper and lower portions are lowered. The side molds 14 and 16 are closed.

In this state, as shown in FIG. 2, the blocking plate 44 is moved to the left side in the drawing (pulled out) and retracted out of the duct 22. At the same time, the cylindrical tube 24 is raised along the outer peripheral surface of the inner duct 22b by a drive mechanism (not shown) to close or shield the notch 25.
By this operation, the hot air sent to the outer duct 22a by the blower 40 provided at the lower end of the inner duct 22b enters the mold 10 from the central space 17 of the lower side mold 16, as indicated by the arrows. The partition plate 15 hits the partition plate 15, changes its direction along the partition plate 15, flows along the inner surface of the rigid core 18, passes through the gap 15 a between the partition plate 15 and the inner side of the rigid core 18, and moves from the lower side to the upper side of the rigid core 18. Then, it further flows along the inside of the rigid core 18 and descends in the inner duct 22b.

  The hot air exchanges heat with the rigid core 18 in the above-described flow, heats the rigid core 18, and heats the raw tire T formed on the outer peripheral surface of the rigid core 18. The heated green tire T is thermally expanded and strongly pressed against the outer surfaces of the tread forming mold 12, the upper and lower side molds 14, 16 and the rigid core 18, so that the inner and outer surfaces of the tire are molded.

  As a result of the heat exchange, the hot air whose temperature has been lowered is reheated by the heater 42 while descending the inner duct 22b, and sent out to the outer duct 22a by the blower 40. The hot air sent out to the outer duct 22a exchanges heat with the rigid core 18 while flowing along the above-mentioned path. The raw tire T formed on the outer peripheral surface of the rigid core 18 heated by this heat exchange is vulcanized. Such forced circulation of hot air is performed until the vulcanization of the tire T is completed.

When the vulcanization of the tire T is completed, the shut-off plate 44 is moved from the retracted position to the shut-off position in FIG. 1 to shut off the hot air flow path between the duct 22 and the vulcanizing mold 10 and vulcanizing mold. The hot air should not come into contact with the outside air even if 10 is opened. At the same time, the cylindrical tube 24 is lowered along the outer peripheral surface of the inner duct 22b to expose the notch 25 of the inner duct 22b to the outer duct as described above, and the blocking plate 44 blocks the pipe line. As a result, the hot air having no place to go directly flows into the inner duct 22b from the outer duct 22a.
In this way, the vulcanization mold 10 is opened while the hot air is forcedly circulated in a state where the hot air is completely blocked from the outside air in the central mechanism of the vulcanizer, and the vulcanized tire T is taken out from the mold 10.

As described above, according to the present embodiment, when the raw tire T is mounted on the vulcanizing mold 10 of the vulcanizer, the hot air flowing into the mold 10 is blocked by the blocking plate 44 so that the hot air is generated. The hot air is prevented from coming into contact with the outside air and is forcedly circulated only within the central mechanism of the vulcanizer 1, that is, forcedly circulated while being heated between the inner and outer ducts 22b and 22a. Temperature can be maintained.
As a result, after the green tire is accommodated in the vulcanization mold 10 and the mold is closed, the hot air temperature at the initial stage of vulcanization decreases as in the conventional case, or the variation in heating in the tire circumferential direction increases, It does not cause problems such as adversely affecting physical properties.

(Second Embodiment)
Next, a tire vulcanizer and a vulcanization method according to a second embodiment of the present invention will be described with reference to the drawings.
FIG. 3 is a longitudinal sectional view of an essential part showing a vulcanization standby state of the vulcanizer according to the second embodiment of the present invention, and FIG. 4 shows a state in which the raw tire and the rigid core 18 are set in the vulcanizer. FIG. 5 is a longitudinal sectional view showing a state in which the blocking plate of the vulcanizer is retracted, and FIG. 6 is a longitudinal sectional view of the vulcanizer during vulcanization.

About the vulcanizer 1 of illustration, the same number is attached | subjected to the location same as the vulcanizer 1 in 1st Embodiment already demonstrated. That is, the mold 10 of the vulcanizer 1 is similar to the first embodiment, as shown in FIGS. 3 to 6, the tread forming mold 12 constituting the outer mold, and the tread forming mold. The upper and lower side molds 14 and 16 and the rigid core (inner mold) 18 are arranged above and below the frame 12.
The molds 12, 14, 16, and 18 have the same materials and configurations as those already described.

  As shown in FIG. 3, the vulcanizer 1 in the second embodiment is a duct that forms the central mechanism of the vulcanizer 1 on the upper side of the central space 17 of the upper and lower side molds 14, 16. A (vent pipe) 22 is attached. The duct 22 is formed in a double pipe structure including an outer duct 22a and an inner duct 22b having a smaller diameter and being concentrically arranged with the outer duct 22a in the same manner as the conventional one shown in FIG. 8B. In the drawing, the lower end of the outer duct 22 a reaches the blocking plate 44 disposed on the upper surface of the upper side mold 14.

The inner duct 22b has a lower end above the lower end of the outer duct 22a so that a circulation path 22c for circulating hot air fed from the outer duct 22a is formed between the lower end of the inner duct 22b and the blocking plate 44. Is located.
At the upper end of the inner duct 22b, hot air from the inner duct 22b is fed to the outer duct 22a through a gap between the inner duct 22b and the outer duct 22a, and the hot air is forcedly circulated through the inner and outer ducts 22b and 22a. A blower 40 that is a heating medium feeding means for causing the heating medium is disposed.
Further, a heater 42 is disposed in the inner duct 22b, and the hot air forcedly circulated by the blower 40 is heated by the heater 42 when passing through the inner duct 22b.

On the upper surface of the upper side mold 14, a blocking plate 44 (44a, 44b) for blocking the flow of hot air between the duct 22 and the vulcanizing mold 10 can be pulled out by a driving mechanism (not shown). Are freely slidable. The blocking plate 44 can be divided at the center thereof, and includes a left blocking plate 44a slidable in the left direction and a right blocking plate 44b slidable in the right direction in the state shown in FIG. .
When the left blocking plate 44a and the right blocking plate 44b are closed to block the flow of hot air between the duct 22 and the opening of the upper side mold 14, the hot air sent by the blower 40 to the outer duct 22a is The hot air is forced to circulate between the inner and outer ducts 22b and 22a by flowing into the inner duct 22b through 22c.

  As shown in FIG. 4, a partition plate 15 is arranged inside the rigid core 18, and between the outer periphery of the partition plate 15 and the inner periphery of the rigid core 18, as in the first embodiment. Is formed with a gap 15a through which hot air flows.

Inner and outer guides 23b and 23a that can be fitted to the inner and outer ducts 22b and 22a are disposed in the central space 17 of the upper and lower side molds 14 and 16, respectively.
The central mechanism composed of the inner and outer ducts 22b, 22a and the like can be moved up and down in the axial direction by a driving mechanism (not shown) when the blocking plate 44 is opened. That is, when the shut-off plate 44 is closed, the lower end portion of the outer duct 22a at the raised position comes into contact with the top face of the shut-off shut-off plate 44, and the hot air flow path between the central mechanism and the vulcanizing mold 10 is shut off. However, when the blocking plate 44 is opened, the central mechanism is lowered to fit the lower ends of the inner and outer ducts 22b and 22a to the upper ends of the inner and outer guides 23b and 23a, respectively. . Thus, the inner and outer ducts 22b and 22a are communicated with the flow passage formed in the rigid core 18 (see FIG. 6).

Next, operation | movement of the tire vulcanizer 1 which concerns on 2nd Embodiment which consists of the above structure is demonstrated with reference to FIGS.
In the vulcanizer 1 during the preheating standby shown in FIG. 3, the blocking plate 44 is operated to block between the duct 22 and the central space 17 on the upper side mold 14 side.
In this state, the hot air heated by the heater 42 in the inner duct 22b is fed to the outer duct 22a by the blower 40, but the blocking plate 44 prevents the inflow into the vulcanization mold 10 as a result. It flows into the inner duct 22b through the circulation path 22c.
Thus, the hot air is forcibly circulated only in the central mechanism, that is, between the inner and outer ducts 22b and 22a, and does not come into contact with the outside air, so the temperature of the hot air sent to the outer duct 22a is always a stable and constant temperature. Maintained.

  Next, the tread forming mold 12 is opened radially outward from the state of FIG. 3, and the upper side mold 14 is raised together with the central mechanism, and the raw tire T formed on the rigid core 18 is moved to the lower side. Place on mold 16. Thereafter, the tread forming mold 12 is closed inward, the upper side mold 14 is lowered, and the tread forming mold 12 and the upper and lower side molds 14, 16 are closed (see FIG. 4).

In this state, the blocking plate 44 (44a, 44b) is moved to the left and right in the drawing (pulled out) as shown in FIG.
Next, the central mechanism is lowered along the axial direction of the duct 22 by a drive mechanism (not shown), and as shown in FIG. 6, the lower end portion of the outer duct 22a becomes the upper end portion of the outer guide 23a and the lower end portion of the inner duct 22b. Is fitted to the upper end of the inner guide 23a.
As a result, the hot air sent to the outer duct 22a by the blower 40 provided at the upper end of the inner duct 22b is guided by the inner and outer guides 23b and 23a in the central space 17 of the upper side mold 14 as indicated by arrows in the figure. It flows into the rigid core 18 along the upper surface of the partition plate 15 through the gap, and when it reaches the inner end of the rigid core 18, it flows into the space between the lower surface of the plate 15 and the rigid core 18 from the gap 15a. Furthermore, it flows and circulates through the inner guide 23b and into the inner duct 22b.

  During this circulation, the hot air exchanges heat with the rigid core 18 to heat the rigid core 18, thereby heating the green tire T formed on the outer peripheral surface of the rigid core 18. The heated raw tire T is thermally expanded and strongly pressed against the outer surfaces of the tread forming mold 12, the upper and lower side molds 14, 16 and the rigid core 18. As a result, the inner and outer surfaces of the raw tire T are molded. Vulcanization molding is performed.

When the vulcanization of the tire T is completed, the central mechanism is moved to the position shown in FIG. 3 and the blocking plate 44 (44a, 44b) is moved from the retracted position to the blocking position shown in FIG. The hot air flow path between the vulcanizing mold 10 and the vulcanizing mold 10 is blocked so that the hot air does not contact the outside air even when the vulcanizing mold 10 is opened.
In this way, the vulcanizing mold 10 is opened and the vulcanized tire T is taken out from the mold 10 while the hot air is completely blocked from the outside air in the central mechanism and forcedly circulated.

  As described above, according to the present embodiment, since the circulation path 22c is formed in the central mechanism and the central mechanism itself can be driven up and down, the raw tire T is vulcanized in the same manner as in the first embodiment. When the mold 10 is mounted, the hot air flowing into the mold 10 is blocked by the blocking plate 44 to prevent the hot air from coming into contact with the outside air, and the blocked hot air is forced only within the central mechanism of the vulcanizer 1. The hot air can be maintained at a predetermined temperature by circulation.

In the vulcanizer and the vulcanization method in the first and second embodiments described above, it has been described that the blocking plate 44 slides sideways between the retracted position and the blocking position. It is not limited, You may move between a retracted position and the interruption | blocking position by rotating.
The central mechanism is attached to the lower part of the mold 10 in the first embodiment and to the upper part of the mold 10 in the second embodiment. There may be.

FIG. 7 is a longitudinal cross-sectional view of a vulcanizer when an external blower (blower) shown for comparison with each embodiment of the present invention is used.
In this vulcanizer as well, the duct 22 is configured as an inner / outer double pipe, but the blower (blower) 40 is installed outside the vulcanizer instead of in the duct 22 in this way, and is perpendicular to the duct 22. When hot air is sucked and pumped, the flow length reaching the inside of the rigid core (or core) 18 from the hot air heater 42 varies. As a result, variations in the circumferential flow rate and temperature flowing in the rigid core 18 increase.
In this embodiment, since the blower 40 is arranged at the lower end or the upper end of the inner duct 22b, the hot air flow path length from the heater 42 to the rigid core 18 is the same at any position in the circumferential direction of the tire. There is hardly any variation.

  In addition, the blower 40 is disposed at the lower end or the upper end of the inner duct 22b, and the circulation path during preheating and vulcanization is completed inside the double tubular inner and outer ducts 22. It can be configured compactly.

(Example)
In order to see the difference between the vulcanizer of the present invention and the conventional vulcanizer, a comparison experiment between the first embodiment and the conventional vulcanizer was performed.
FIG. 9 is a diagram for explaining a temperature measurement position in the vulcanizer of the conventional and the first embodiment in order to measure the temperature of hot air, and FIG. 9A is a main part longitudinal section showing a thermometer installation position. FIG. 9B is a diagram schematically illustrating the installation position of the thermometer in the circumferential direction of the tire.

  FIG. 10 shows the temperature of hot air in a mold during vulcanization (°) at the positions of tires (0 °, 90 °, 180 °, 270 °) arranged at a central angle of 90 ° in a conventional vulcanizer. It is the graph which measured C), how it changed with progress of vulcanization time (minute), the temperature variation (C) between each position, and its temporal change.

First, the set temperature (target or target temperature) at the time of vulcanization is 200 ° for 15 minutes from the start of vulcanization, and then lowered to 150 °.
Here, as is apparent from this graph, in the conventional vulcanizer, the initial temperature is between 200 ° C. and the temperature is between 180 ° C. and 190 ° C., and the temperature drop is 10 ° C. or more. Is recognized. Therefore, after about 10 minutes, the temperature of the hot air is increased to a maximum of about 215 ° C or higher and a minimum of 207 ° C. In addition, it took about 10 minutes to reach 200 ° C. at all measurement points of the tire.
Furthermore, the variation in the circumferential direction reached a maximum of about 10 ° C. after about 10 ° C. for 10 minutes in the initial state at the time of vulcanization. This variation in temperature adversely affects the physical properties of the tire.

FIG. 11 is a graph showing test results similar to those of the conventional vulcanizer in the vulcanizer according to the first embodiment.
As is clear from this graph, in the first embodiment of the present invention, the hot air at the start of vulcanization is about 200 ° C. and is almost the set temperature, and then rises slightly, but is almost constant for 15 minutes, It turns out that it falls gradually to about 170 degreeC after that. It was also found that the temperature variation at each measurement position separated by an angular interval of 90 ° of the tire was 2 ° C. or less, and this temperature variation was maintained substantially constant during the vulcanization period.
From the above, in the vulcanizer of the present invention, it is clear that vulcanization is performed well as planned and with uniform heating.

It is a principal part longitudinal cross-sectional view which shows the vulcanization standby state of the vulcanizer which concerns on 1st Embodiment. It is a longitudinal cross-sectional view of the vulcanizer during vulcanization. It is a principal part longitudinal cross-sectional view which shows the vulcanization standby state of the vulcanizer which concerns on 2nd Embodiment. It is a longitudinal cross-sectional view which shows the state which set the raw tire and the rigid core to the vulcanizer. It is a longitudinal cross-sectional view which shows the state which retracted the interruption | blocking plate of a vulcanizer. It is a longitudinal cross-sectional view of the vulcanizer during vulcanization. It is a longitudinal cross-sectional view of a vulcanizer using an external blower. FIG. 8A is a longitudinal sectional view of a main part showing the installation position of the thermometer in the vulcanizer, and FIG. 8B is a diagram schematically showing the installation position of the thermometer in the circumferential direction of the tire. In conventional vulcanizers, the relationship between the hot air temperature (° C) in the mold during vulcanization and the lapse of vulcanization time (minutes), and the temperature variation between tire positions (° C) and its change over time It is the graph which showed. It is the same graph as FIG. 9 which shows the test result similar to the conventional vulcanizer in the vulcanizer which concerns on 1st Embodiment. FIG. 11A is a cross-sectional view of a main part showing a preferable blowing structure in a conventional vulcanizer adopting a core vulcanizing method, and FIG. 11B shows another blowing structure in a vulcanizer adopting a core vulcanizing method. It is principal part sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vulcanizer, 10 ... Vulcanization mold, 12 ... Mold for tread formation, 14 ... Upper side mold, 15 ... Partition plate, 15a ... Gap, 16 ... Lower side mold, 17 ... Central cavity, 18 ... Rigid core (inner mold), 20, 22 (22a, 22b) ... Duct (vent pipe), 22c ... Circulation Road, 23 (23a, 23b) ... Guide, 24 ... Cylindrical tube, 25 ... Notch, 40 ... Blower, 42 ... Heater, 44 (44a, 44b) ... Shut-off plate .

Claims (9)

In the vulcanizer that heats the tire inner surface with hot air,
A central mechanism having a vulcanization mold for storing a raw tire, a raw tire heating medium feeding means, a heater, an inner / outer double pipe serving as a heating medium supply / exhaust flow path, and the central mechanism and vulcanization A tire adding device comprising: a blocking means for blocking a flow path of hot air between the molds; and a circulation path for circulating hot air when the blocking means blocks the flow path in the inner and outer double pipes. Sulfur machine. In the tire vulcanizer according to claim 1,
The raw tire is formed on a rigid core, and the rigid core constitutes an inner mold of the vulcanization mold. In the tire vulcanizer according to claim 2,
A tire vulcanizer, characterized in that a partition plate that forms a flow path through which the raw tire heating medium flows along the inner surface of the rigid core is disposed in the rigid core. In the tire vulcanizer according to any one of claims 1 to 3,
The tire vulcanizer characterized in that the blocking means for blocking the flow path of the heating medium between the central mechanism and the vulcanizing mold is a blocking plate that can move forward and backward with respect to the flow path. In the tire vulcanizer according to any one of claims 1 to 4,
A notch portion provided in the inner pipe for forming the circulation path of the heating medium when the flow path of the hot air between the central mechanism and the vulcanization mold is blocked; and means for closing the notch portion; A tire vulcanizer characterized by comprising: In the tire vulcanizer according to claim 5,
The tire vulcanizer characterized in that the means for closing the notch is a cylindrical tube movable along the peripheral surface of the inner tube. In the tire vulcanizer according to any one of claims 1 to 4,
A first position where the center mechanism is brought into contact with the blocking means to block a flow path of the heating medium between the center mechanism and the vulcanization mold; and the inner and outer double pipes are connected to the flow path of the rigid core. A tire vulcanizer comprising means for moving between the second position and the second position for communication with the tire. In the tire vulcanizer according to any one of claims 1 to 7,
The tire vulcanizer, wherein the heater is disposed inside the inner pipe, and the heating medium feeding means is disposed at an end of the inner pipe. A blower, a heater, and a raw tire vulcanizing method in a vulcanizer equipped with a central mechanism having an inner and outer double pipe that serves as a supply / exhaust flow path for a raw tire heating medium,
A preheating step of circulating the heating medium only in a central mechanism while heating, a step of storing a raw tire formed on a rigid core in a vulcanization mold, and the heating medium inside the rigid core and the And a step of heating the green tire by circulating in the central mechanism.

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