JPH046B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> This invention relates to improvements in tire vulcanization methods and equipment.

<Prior Art> Conventionally, tires are vulcanized using a vulcanizing apparatus as shown in cross-section in FIG.

To explain the outline of this device, reference numeral 1 denotes a bladder supported by an upper clamp ring 2 and a lower clamp ring 3, and is shown in a state in which it is expanded by supply of a vulcanizing medium.

(Please note that the rings around the upper and lower clamp rings,
Illustrations of molds, tires, etc. are omitted. ) The upper clamp ring 2 is supported by the center post 4. 5 is a bug cylinder. 6 is a bag cylinder head. The lower clamp ring 3 is supported by the bag cylinder 5. 7 is a baffle plate supported by the lower clamp ring 3, and this baffle plate 7 and the lower clamp ring 3
In between, a supply port 9 of a steam or gas supply pipe 8 and a discharge port 11 of a discharge pipe 10 are provided at a position opposite thereto.

Note that 12 is a diaphragm valve operated by air pressure sent from a solenoid valve directly connected to a timer (not shown).

Vulcanization of the tire (not shown) in the vulcanization chamber by such a device includes, for example, a shaping process,
Known operating steps such as steaming, gassing, and evacuation steps are completed.

<Problems to be Solved by the Invention> However, this method has a drawback in that both steam and gas are supplied from the same supply port 9.

That is, when the gas following the steam process is supplied from the supply port 9 located below the vulcanization chamber 13, the specific gravity of the gas is greater than that of the steam, so that the gas is supplied to the lower part 14 in the vulcanization chamber 13. It has a strong tendency to accumulate, making it difficult to mix uniformly with the steam filling the chamber.

Therefore, on the contrary, steam accumulates in the upper part 15 of the vulcanization chamber, and as a result, the upper part 15 is 7 to 8 degrees Celsius higher than the standard temperature of the vulcanization chamber, and the lower part 14 is 7 to 8 degrees Celsius lower than the reference temperature of the vulcanization chamber. It has been pointed out that there is a temperature difference of 15 to 16°C between the upper and lower parts of the tire sidewall, which makes it difficult to obtain a uniformly cured tire.

In addition, as another conventional example, Japanese Patent Application Laid-Open No. 56-28843 discloses that the injection direction of the injection supply port of the internal pressure heat medium provided in the clamp ring hub is set to the inner surface of the bladder above the bladder equatorial plane, that is, the vulcanized A configuration is disclosed in which it is set toward the vicinity of the top of the chamber.

However, this conventional vulcanizing device
As in the conventional example shown in the figure, since steam and gas are supplied from the same supply port, it is not possible to make the respective injection directions of steam and gas different. For this reason, if the supply port is directed toward the top of the vulcanization chamber, the steam will be sprayed toward the top of the vulcanization chamber during the steam process, resulting in unbalanced heat dispersion in the chamber and tire It is unavoidable that the temperature difference between the upper and lower parts of the sidewall section becomes large.

As a result, this conventional example has the drawback that it is difficult to obtain a uniformly vulcanized tire because of over-vulcanization or insufficient vulcanization of the tire sidewall portion.

<Means for Solving the Problems> The present inventor has developed various methods and devices to solve the above-mentioned drawbacks of tire vulcanization using conventional vulcanization devices and to find a vulcanization method and device that can always perform uniform vulcanization. As a result of our studies, we have arrived at this invention.

That is, the first feature of this invention is that steam and gas are supplied to the tire set in the vulcanization chamber from separate supply ports, and the gas is injected toward the vicinity of the top of the vulcanization chamber. and
Furthermore, the second feature is that a steam supply pipe and a gas supply pipe are provided that penetrate inside the bag cylinder, and a pipe is installed at the supply port of the gas supply pipe at an angle near the top of the vulcanization chamber. Furthermore, the third feature is that steam and gas are alternately supplied.

<Example> The present invention will be described below based on FIGS. 2 to 5 showing one example thereof.

In Fig. 2, 21 is the upper clamp ring 2.
2 and a lower clamp ring 23. (The rings, molds, tires, etc. around the upper and lower clamp rings are omitted from illustration.) Then, the supply port 27 of the steam supply pipe 26 that penetrates the inside of the bag cylinder 25 is arranged at the upper part of the lower clamp ring 23. A supply port 29 of the gas supply pipe 28 that also penetrates inside the bag cylinder 25 is provided above the position facing this, and the supply port is angled in the direction of the black arrow, that is, in the upper direction of the vulcanization chamber. The pipe 24 is loosely connected, whereby gas is injected near the top of the vulcanization chamber 33 as indicated by the black arrow. This gas supply pipe 28 also serves as an exhaust pipe during the latter half of the vulcanization process, such as exhaust and vacuuming. 30 is a diaphragm valve.

To perform tire vulcanization using a vulcanizing device with such a structure, for example, first steam (2Kg/cm ² ) is supplied into the vulcanization chamber 33 from the supply port 27 for shaping, and then steam (15Kg/cm 2 ) is supplied into the vulcanization chamber 33 for shaping. cm ² ) is similarly supplied from the supply port 27 and heated, and then gas from the gas supply pipe 28 is supplied from the pipe 24 connected to the supply port 29 toward the top of the vulcanization chamber.

As a result, the gas is injected into the upper part 32 of the vulcanization chamber 33 filled with steam, so that the steam and gas are sufficiently mixed and the downward settling speed of the gas can be slowed down, thereby reducing the tire sidewall. It is possible to reduce the temperature difference between the upper and lower parts to about 5 to 6° C., thereby preventing over-vulcanization or under-vulcanization of the tire sidewall portion, and achieving more uniform vulcanization.

The above has described an embodiment in which the gas supply injection is performed from a high position toward the upper part 32 of the vulcanization chamber 33 based on FIG. By devising the supply method, it is possible to reduce the temperature difference between the upper and lower parts of the tire sidewall.

That is, for example, first steam (2 kg/cm ² ) is supplied for shaping, and then steam (5 kg/cm 2 ) is supplied again.
Kg/cm ² ) is supplied from the supply port 27 for 30 seconds for heating, then gas (10Kg/cm ² ) is supplied for 30 seconds from the pipe 24 connected to the supply port 29, and then steam (15Kg/cm ² ) is supplied again from the pipe 24 connected to the supply port 29. is supplied from the supply port 27 for 6 minutes, then gas (21Kg/cm ² ) is supplied from the pipe 24 connected to the supply port 29, then exhausted from the discharge port 29, and finally vacuumed to complete one cycle of the vulcanization process. This is the method of ending the process.

In another example, the above alternating supply of steam and gas is performed by supplying gas (5Kg/cm ² ) for 30 seconds, then supplying steam (15Kg/cm ² ) for 6 minutes, then supplying gas (21Kg/cm ² ) for 7 minutes. It may be supplied for minutes.

In this way, if the steam and gas supply positions shown in Fig. 2 are used, and if the steam and gas are supplied in the above-mentioned alternate manner, the effect becomes even more remarkable. can be reduced to about 2-3°C.

Note that the opening 34 of the steam supply port 27 of this invention
The opening 35 of the gas supply port 29 may be provided at one location in the circumferential direction as shown in FIG.
As shown in the figure, several to ten holes with a diameter of 2 to 6 mm are provided in the circumferential direction.

Next, as shown in FIG. 2, the apparatus of the present invention, in which steam is supplied from the supply port at the top of the lower clamp ring, and gas is supplied from the pipe connected to the gas supply port located above it, and when both steam and gas are We conducted an actual tire vulcanization test using a conventional device as shown in Figure 1, which performs vulcanization from the supply port at the bottom of the plate. When the vulcanization temperature difference R between the upper and lower portions of the sidewall portion was investigated, the results shown in FIGS. 5A and 5B were obtained.

In addition, in this test, the device of the present invention shown in FIG.
21 kg of gas was supplied from a pipe connected to the gas supply port, and the conventional device shown in FIG.

From FIG. 5, it can be seen that A according to the present invention has a temperature difference R=4 even after 1 to 5 minutes have passed after switching from steam to gas.
~8°C, especially after 5 minutes of switching to gas the temperature difference was only 4°C.

On the other hand, in B using the conventional device, the temperature difference R is
The temperature was very high at 13 to 17°C, and it was confirmed that a more uniform tire vulcanization state could be obtained with the apparatus of this invention.

<Effects of the Invention> As explained above, according to the present invention, steam and gas are supplied from different supply ports.
By injecting the gas toward the vicinity of the top of the vulcanization chamber, the steam and gas can be sufficiently mixed, and the downward sedimentation rate of the gas can be slowed down. Therefore, the temperature difference between the upper and lower parts of the tire sidewall portion is reduced, and over-vulcanization or under-vulcanization of the tire sidewall portion can be prevented, so that a uniformly vulcanized tire can be obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a conventional device used for tire vulcanization, Fig. 2 is a sectional view of a tire vulcanizing device of the present invention, Fig. 3 is a sectional view of the opening of the steam supply port, and Fig. 4 is a gas supply FIGS. 5A and 5B, which are cross-sectional views of the mouth opening, are charts showing the temperature difference between the upper and lower sidewalls of tires according to the present invention and the conventional apparatus. 21... Bladder, 22... Upper clamp ring, 23... Lower clamp ring, 24... Pipe, 27... Steam supply port, 29... Gas supply port.

Claims (1)

[Claims] 1. In a method of vulcanizing a green tire by sequentially supplying a vulcanizing medium such as steam or gas into a mold in which a green tire is set, the steam supply and the gas supply are provided through different supply ports. A tire vulcanization method characterized in that the process is carried out from the beginning and gas is injected toward the upper part of the vulcanization chamber. 2 In a method of curing green tires by sequentially supplying a vulcanizing medium such as steam or gas into a mold in which a green tire is set, the steam and gas are supplied from different supply ports, and the gas is A tire vulcanization method characterized by injecting steam and gas toward the upper part of a curing chamber and alternately supplying steam and gas. 3 In a vulcanizing device that vulcanizes a green tire by supplying a vulcanizing medium such as steam or gas into a mold in which the green tire is set, the upper clamp ring supported by the center post and the bag cylinder The bladder is supported by a lower clamp ring, and has a steam supply pipe and a gas supply pipe that penetrate inside the bag cylinder, and each supply port for the steam supply pipe and the gas supply pipe is provided separately, and the gas supply port is A tire vulcanizing device, characterized in that a pipe is connected at an angle near the top of a vulcanizing chamber, and gas is injected through the pipe.