JPH059243B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) This invention relates to a method and apparatus for vulcanizing elastomer articles such as automobile tires.

(Prior Art and Problems to be Solved by the Invention) Conventionally, as a method for curing elastomer articles such as automobile tires, as shown in FIG. At the same time, a bladder 3 is placed along the inner surface of the elastomer article, and a heating medium such as steam at a predetermined temperature and pressure is supplied into the internal space 6, and when the elastomer article reaches the standard temperature required for vulcanization, or When the reference time has elapsed, the supply of the heating medium is stopped, and then a pressurized medium (combustion gas, nitrogen, etc.) with a higher pressure than the heating medium is supplied from the blow-off nozzle 5 provided in the central mechanism 4 of the vulcanizer. The heating medium is supplied throughout the entire heating process by blowing it into the elastomer article, increasing the pressure inside the elastomer article 2 with this high-pressure gas, and maintaining it until the end of the remaining time of the heating process. A vulcanization method is being used, which aims to significantly reduce energy costs compared to the vulcanization method.

In the above method, the temperature of the pressurized gas is relatively lower than that of steam, and the parts that the gas flow hits (lower bead, lower sidewall, etc.) are cooled and lowered in temperature, and the gas at the time of supply is lower than that of steam. It is relatively cold and has a high specific gravity and tends to accumulate in the lower part of the interior of the elastomeric article, thus reducing the temperature of the lower sidewall area with which the gas comes in contact. On the other hand, since the gas is introduced at a higher pressure than the steam pressure, the steam is temporarily adiabatically compressed and its temperature increases, and due to the density difference, the steam is biased towards the upper sidewall area of the elastomer article. .

Therefore, inside the elastomer article, there will be a steam layer 61 at the top, a gas layer 62 at the bottom, and a drain reservoir 63 created by the cooling of the steam at the bottom. This results in a relatively high temperature in the upper sidewall area. That is, as shown in FIG. 2, the temperature inside the elastomer article gradually increases as shown by curves 10 and 11 due to the supply of steam;
When gas is then supplied, the point a of the upper bead of the elastomer article further rises as shown by curve 12, and the point b near the lower bead of the elastomer article rises further as shown by curve 13.
It decreases slightly as shown in .

The above phenomenon, that is, a temperature difference inside the elastomer article 2 (for example, in the upper and lower bead areas)
13℃), which is not completely eliminated by the end of vulcanization, and the upper and lower parts of the elastomer article will have different degrees of vulcanization, which is unfavorable in terms of quality. Since the required vulcanization time is set depending on the side, a longer time than necessary is required, which is not preferable from the viewpoint of productivity and energy saving.

This invention was made to solve these conventional drawbacks; no temperature difference occurs inside the elastomer article during vulcanization, uniform vulcanization occurs, and vulcanization time is shortened. The present invention provides a method for vulcanizing an elastomer article and an apparatus therefor, which can reduce energy loss.

(Means for Solving the Problems) The gist of the first invention is to supply a heating medium such as steam to the inside of a mold in a vulcanization process in which a vulcanizing medium is sequentially supplied to the inside of an elastomer article for vulcanization. The elastomer article loaded in the elastomer article is heated and pressurized, and when the elastomer article reaches a reference temperature necessary for causing a vulcanization reaction or a reference time has elapsed, the supply of the heating medium is stopped, and then the vulcanization reaction is performed. In the middle of the medium supply piping system, a pressurized medium such as nitrogen with a higher pressure than the previously supplied heating medium is supplied at high speed so as not to mix with the heating medium, so that the previously supplied heating medium is the same as the pressurized medium. The remaining time of the heating process is such that 70% to 100% of the internal volume of the elastomer article in the mold is occupied by the heating medium compressed to the same pressure level as the pressurizing medium. It is designed to be maintained until the end.

Further, the gist of the second invention is that in a vulcanization step in which a vulcanizing medium is sequentially supplied inside an elastomer article and the elastomer article is vulcanized, a heating medium such as steam is supplied to heat and pressurize the elastomer article loaded into a mold. , when the elastomer article reaches the reference temperature necessary for the vulcanization reaction to occur or when the reference time has elapsed, the supply of the heating medium is stopped, and then, in the middle of the supply piping system of the vulcanization medium, the supply of the heating medium is stopped. A pressurized medium such as nitrogen at the same pressure as the heating medium supplied to the mold is fed at high speed so as not to mix with the heating medium, so that 70% to 100% of the internal volume of the elastomer article in the mold is occupied by the heating medium. This state is maintained until the end of the remaining time of the heating process.

Further, the gist of the third invention is that in a vulcanizing device that sequentially supplies a vulcanizing medium into the inside of an elastomer article loaded in a mold and vulcanizes it by heating and pressurizing, the vulcanizing medium is compressed in the middle of the supply piping system. A container is provided, and the container compresses the previously supplied heating medium by rapidly feeding a pressurized medium at high pressure into the container, so that 70% to 100% of the interior of the elastomer article is at the same pressure as the pressurized medium. It has a volume sufficient to be occupied by a heating medium compressed to a level and to maintain this compressed state for the remainder of the heating process.

(Function) In the configurations of the first and third inventions described above, the inside of the elastomer article is in the initial stage of vulcanization, that is, until the reference temperature necessary to cause the vulcanization reaction is reached.
Or, by the time the reference time has elapsed, the interior of the elastomer article is occupied only by steam, and after the reference temperature is reached or after the reference time has elapsed, the inside of the elastomer article is filled with adiabatic compressed steam by the high-speed supply of gas at a higher pressure than the previously supplied steam. 70-100% of the elastomeric product is occupied by the elastomer, and no cold gases enter into the same interior or exceed permissible limit levels, ensuring efficient and uniform vulcanization without temperature differences within the elastomer article. It is done.

Furthermore, in the configuration of the second invention, after the reference temperature is reached or after the reference time has elapsed, 70 to 100% of the interior of the elastomer article is occupied by steam due to the high-speed supply of gas at the same pressure as the previously supplied steam. Low-temperature gas does not enter at all or exceeds a permissible limit level, and the same effect as in the first invention is produced.

(Example) In FIG. 1, the mold 1 and the central mechanism 4 of the vulcanizer are the same as those of the above-mentioned conventional device, but they are connected to a nozzle 5, and include steam (heating medium), pressurized gas (pressurized medium), etc. A tank or header 8 as a compression container is connected to the middle of the vulcanizing medium supply pipe 7 via a switching valve 71, and a vacuum pipe (not shown) and Exhaust piping is connected. The lower section of this tank 8 is connected via a valve 81 to a heating steam supply and via a valve 82 to a pressurized gas supply. Valve 8
3 is for draining pressurized gas and drain collected at the bottom of the container. Further, a shaping medium supply source (not shown) is connected to the switching valve 71 via a predetermined pipe.

The volume of the tank 8 is set so that the sum of the tank volume, the volume of the pipe 7, and the volume of the internal space 6 of the elastomer article is equal to or greater than the volume that decreases during adiabatic compression of steam.

Next, a method of vulcanizing a tire as an elastomer article using this apparatus will be explained. First, as is known, the tire 2 is mounted in the mold 1, and a shaping medium is supplied from the nozzle 5 into the internal space 6 through the pipe 75, the switching valve 71, and the pipe 7 so that the bladder 3 is placed along the inner surface of the mold. The bladder 3 is pressed onto the inner surface of the tire 2.

Then, the switching valve 71 is switched, and the valve 8 is switched.
Open 1 and pass from tank 8 to pipe 7 15Kg/cm ²
Steam with a pressure of At this time, valve 82 is closed.
This steam supply raises the temperature of the internal space 6 to about 180°C. This temperature is the temperature necessary to cause the tire vulcanization reaction, and in the above example, 5 minutes is the time required to cause the tire vulcanization reaction. When the reference temperature is reached or the reference time has elapsed, the valve 81 is closed, and this control is performed by a process timer.

Then, the valve 82 is opened and a high pressure pressurized gas of 18 kg/cm ² is supplied to the tank 8. This gas is a low-temperature gas (for example, 40° C.) that is about room temperature. By supplying this high-pressure gas, the steam in the tank 8, the piping, and the tire is compressed to increase the pressure of the steam in the internal space 6, thereby performing so-called adiabatic compression. Compression by this gas increases the pressure of the steam to 18 Kg/cm ² , which is the same pressure as the high-pressure gas. By maintaining this pressure for the remainder of the heating process, for example, about 5 minutes, the temperature in the internal space 6 increases to the maximum temperature ( (for example, 200°C), and a predetermined vulcanization is performed.

By supplying the gas into the tank 8, the steam in the tank 8 is compressed, and the gas is supplied at high speed (for example, several to several tens of seconds) so that the low temperature gas does not mix with the high temperature steam. In addition, by supplying gas at the above pressure, the boundary between the gas and steam is in the tank 8 or in the piping 7.
so that no gas reaches the tire internal space 6, i.e. 100% of the tire internal space 6 is occupied by compressed steam, or even if gas enters the tire internal space 6, it exceeds the permissible limit level. tank 8 so that no more than 70% of the tire interior space 6 is occupied by compressed steam.
The volume is set based on the relationship between the volume of the pipe 7, the volume of the internal space 6, and the steam reduction volume during compression.

After the above-mentioned vulcanization, the valve 72 is opened and the mixture of gas and steam in the interior space 6, piping 7 and tank 8 is discharged through the discharge line. Then valve 7
2 and open the valve 73, remove the bladder 3 from inside the tire 2 with a vacuum, open the upper mold of the mold 1, and remove the vulcanized tire 2.
Take out. However, in the case of bladderless vulcanization, the vacuum step described above is not required.

In addition, when a nylon carcass ply tire is used as the tire 2, the cooling water is introduced into the tire after the heating process, and after the vulcanization is completed, the mixture of gas and steam and the mixture of gas and cooling water are discharged from the discharge line. do.

As mentioned above, the steam in the tire internal space 6 is compressed by high pressure gas through the compression container 8 until it reaches the same pressure, and this compressed steam fills 70 to 100% of the tire internal space 6, and this state is used in the heating process. When maintained until the end of the time, the temperature of the tire 2 is as shown in Figure 2, and the difference in vulcanization temperature between the upper and lower bead portions a and b of the tire is 13 in the case of the conventional method shown by solid lines 12 and 13. ℃, whereas in the case of the method of this invention shown by broken lines 14 and 15 in the figure, the temperature was significantly reduced to 8℃, which enabled uniform vulcanization and the production of tires with excellent uniformity. It turns out that

Moreover, by eliminating the temperature difference, the vulcanization time can be shortened, and productivity can be improved and energy loss can be reduced.

Further, the compression container may be a spirally wound tube as shown in FIG. 4, and the volumetric design of the tube in this case is the same as that of the tank in the above embodiment. In addition, in another embodiment, when the elastomer article reaches the reference temperature required for vulcanization or after the reference time has elapsed, the supply of the heating medium is stopped, and the supply is stopped earlier in the middle of the vulcanization medium supply piping system. 70-100 of the internal volume of the elastomeric article by supplying a pressurized medium such as _N2 at the same pressure as the heated heating medium.
It is possible to adopt a method in which control is performed such that % is occupied by the heating medium, and this state is maintained until the heating process is completed. In this case, the mechanism is the same as the apparatus of the first embodiment in FIG. 1 except for the part surrounded by broken lines, and the differences are as shown in FIG. 5. This is a configuration that does not have 8. In this case, it is also possible to connect the compression vessel 8 of the first embodiment or the spirally wound pipe body 9 of FIG. It becomes easier to control the amount of gas.

In addition, although the above embodiment shows an example in which the invention is applied to a center post type vulcanizer, the present invention can also be applied to other commonly used vulcanizers, such as those without a center post, or It can also be applied to a type of vulcanizer commonly known as a bagwell, which has a cylindrical container with multiple nozzles all around the top and a recovery device at the bottom of the container. It is also applicable to a vulcanizer that does not use a bladder.

(Effects of the Invention) As explained above, according to the present invention, the pressurizing medium is supplied at high speed after the heating medium that is supplied first, which is necessary for causing the tire vulcanization reaction. After a certain standard time has elapsed, 70-100% of the interior of the elastomer article is occupied only by steam at a predetermined pressure, and there is no unnecessary cooling with low-temperature gas, so there is no temperature difference inside the elastomer article. Uniform vulcanization is performed without any occurrence of vulcanization. In addition, unlike conventional methods, there is no need to install a vulcanization timer in areas where vulcanization is delayed.
Vulcanization time can be shortened, productivity can be improved, and energy loss can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional explanatory diagram showing an embodiment of the present invention; FIG. 2 is a comparative diagram of the temperature and time during vulcanization of an elastomer article by the apparatus and the conventional method;
FIG. 3 is an explanatory diagram of the inside of a mold according to the conventional method, FIG. 4 is an explanatory diagram of another embodiment of the compression container, and FIG. 5 is an explanatory diagram of a piping portion showing another embodiment. 1... Mold, 2... Elastomer article, 3...
Bladder, 5... Nozzle, 6... Internal space, 7...
...Piping, 8...Tank, 9...Pipe body.

Claims (1)

[Claims] 1. In a vulcanization step in which a vulcanizing medium is sequentially supplied inside an elastomer article and vulcanized, a heating medium such as steam is supplied to heat and pressurize the elastomer article loaded in a mold, When the elastomer article reaches the reference temperature required for the vulcanization reaction to occur or when the reference time has elapsed, the supply of the heating medium is stopped, and then the A pressurized medium such as nitrogen, which has a higher pressure than the heating medium supplied to the metal, is supplied at high speed so as not to mix with the heating medium, and the heating medium supplied earlier is compressed to the same pressure level as the pressurized medium. 70% to 100% of the internal volume of the elastomer article in the mold
A method for vulcanizing an elastomer article, characterized in that a state in which the elastomer is occupied by a heating medium compressed to the same pressure level as the pressurizing medium is maintained until the end of the remaining time of the heating step. 2 In the vulcanization process in which vulcanizing media are sequentially supplied inside the elastomer article for vulcanization, the elastomer article loaded in the mold is heated and pressurized by supplying a heating medium such as steam, and the elastomer article undergoes a vulcanization reaction. When the reference temperature required to cause the vulcanization is reached or the reference time has elapsed, the supply of the heating medium is stopped, and then, in the middle of the supply piping system of the vulcanization medium, the supply of the heating medium is replaced with the previously supplied heating medium. During the heating process, a pressurized medium such as nitrogen at the same pressure is fed at high speed so as not to mix with the heating medium, so that 70% to 100% of the internal volume of the elastomer article in the mold is occupied by the heating medium. A method of vulcanizing an elastomer article, characterized by maintaining the vulcanization until the end of the remaining time. 3 In a vulcanizing device that sequentially supplies a vulcanizing medium to the inside of an elastomer article loaded in a mold and vulcanizes it by heating and pressurizing, a compression container is provided in the middle of the vulcanizing medium supply piping system, and this container is , the high-pressure pressurized medium is rapidly fed into this container, compressing the previously fed heating medium, and causing the inside of the elastomer article to be compressed.
An elastomer characterized in that 70% to 100% of the volume is occupied by a heating medium compressed to the same pressure level as the pressurizing medium, and the volume is sufficient to maintain this compressed state until the end of the remaining time of the heating process. Article vulcanization equipment. 4. The vulcanizing apparatus for elastomer articles according to claim 3, wherein the compression container is a tank. 5. The vulcanizing apparatus for elastomer articles according to claim 3, wherein the compression container is a spiral tube. 6 The volume of the compression container is equal to or greater than the volume that the sum of the volume inside the elastomer article in the mold, the volume of the piping system between the compression container and the mold, and the volume of the compression container decreases during adiabatic compression. An apparatus for curing elastomer articles according to claim 3 or 4, characterized in that: 7. Claims 3 to 6, characterized in that the lower section of the compression vessel is connected via a valve to a source of pressurizing medium and heating medium and to an exhaust pipe. A vulcanization device for an elastomer article according to any one of the above.