JPS6252690B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vulcanizing device for uniformly vulcanizing a rubber molded product containing a cored metal in a short time.

Rubber molded products such as weather strips and trims often have a core metal embedded in them to improve their shape retention. When vulcanizing these cored rubber molded products at elevated temperatures, there are two methods: passing the extruded rubber molded product through a heating furnace in which heated glass powder is suspended; A method is being adopted to allow it to pass through.

However, these methods require post-processing such as removing glass powder adhering to the molded product, pose problems in the working environment, and have problems in that the heat capacity of the medium is large and the energy efficiency is low.

Therefore, recently, a method that uses microwave dielectric heating and hot air heating in combination has come to be used for vulcanizing rubber molded products containing cored metal. However, with microwave dielectric heating, the core metal is not heated, and therefore the rubber that is in contact with the core metal absorbs heat from the core metal, making it difficult to raise the temperature.
There is a problem of uneven heating.

By the way, high-frequency induction heating has been found to be effective for heating the core metal, and therefore, it is possible to use this high-frequency induction heating and the microwave dielectric heating in combination, but in this case, both heating means may be used. If they are operated simultaneously at the same location, the oscillation outputs will electromagnetically interfere with each other and effective heating will not be possible, so it is necessary to separate both heating means. Therefore, the apparatus requires a large space, and furthermore, since the rubber is heated over time after heating the core metal, there remains the problem that it is difficult to uniformly raise the temperature of the rubber molded product.

Therefore, the present invention achieves uniform heat vulcanization in a short time by integrating a microwave dielectric heating means and a high frequency induction heating means and operating both means alternately in a short heating cycle time. be.

Embodiments of the heating device of the present invention will be described below with reference to the drawings.

The heating furnace 1 includes a cylindrical applicator 2 made of aluminum constituting an inner wall, an outer wall 3 made of iron plate, and a heat insulating material 4 made of glass wool interposed therebetween.
It is basically composed of. At both axial ends of the heating furnace 1, there are provided an inlet 5a and an outlet 5b of an extruded long rubber molded product with a cored metal, and the outer peripheries of these are made of aluminum to prevent microwave leakage. It is formed by filter members 6a and 6b.

A waveguide 7 made of an aluminum pipe is inserted at the end of the peripheral wall of the heating furnace 1 at a position close to the introduction port 5a, one end of which opens into the applicator 2, and the other end of which is connected to the microwave. It is connected to an oscillator 8.

The center part of the applicator 2 has a slightly large diameter, and an inner cylinder member 9 made of Teflon, which is an insulator, is fitted and fixed on the inner periphery of this large diameter part 2a.
A copper pipe 10 is embedded in a coil shape in the circumferential direction. This copper pipe 10 is led out from both ends of the inner cylinder member 9 to the outside of the peripheral wall of the heating furnace 1 and is connected to a high frequency oscillator 11. Also this copper pipe 1
Cooling water is allowed to flow inside the tank. An insulating tape (not shown) is wrapped around the outer periphery of the copper pipe 10 in a portion inside the peripheral wall of the heating furnace to insulate it from the applicator 2 and the outer wall 3, and furthermore, a tape for preventing microwave leakage is wrapped around the outer periphery of the copper pipe 10. Filter member 12a, 1
2b is provided.

A blast pipe 14 of a hot air generator 13 is inserted into the peripheral wall of the heating furnace 1 at a position close to the introduction port 5a, and its tip opens into the applicator 2, and this blast pipe is connected to the heat insulating material 4a. covered with.

The microwave oscillator 8 and the high frequency oscillator 1
1 is connected to the power supply via a timer switch,
An electric circuit (not shown) is configured to energize both oscillators 8 and 11 in a predetermined cycle. The apparatus of the present invention is supported by support legs 15, and is installed on a path through which a rubber molded product containing a core metal extruded from an extrusion molding machine is transferred.

In the vulcanizing apparatus configured as described above, the rubber molded product (all not shown) formed by the extrusion molding machine enters the heating furnace 1 through the inlet 5a and the outlet 5b.
and is continuously transported.

At this time, the output from the microwave oscillator 8 (oscillation frequency around 2450 MHz, output approximately 5 to 10 KW) is transmitted into the applicator 2 through the waveguide 7, and is transmitted from the introduction part side of the rubber molded product to the output part side. proceed towards. Since rubber has dielectric loss, it is dielectrically heated uniformly by microwaves.

After dielectric heating for about 2 seconds, the timer switch is activated to turn on the high frequency oscillator 11, and its output (oscillation frequency around 400KHz, output 5
~10KW) flows near the copper pipe 10, a magnetic flux is generated in the center of the applicator 2, and this magnetic flux causes the core metal inside the rubber to generate heat due to eddy current loss due to induced current. This induction heating is performed for about 2 seconds, and thereafter the heating cycle is continued. During this time, hot air is supplied from the hot air generator 13 into the applicator 2, and the applicator 2
It keeps the inside warm and promotes the heating of rubber molded products.

As described above, the vulcanizing apparatus of the present invention integrates dielectric heating means using microwaves and induction heating means using high frequency waves, and has extremely high thermal efficiency, and the temperature of the rubber and core metal can be raised at the same time. Sulfurization can be done quickly and uniformly. In addition, since both heating means are integrated, the space required for the equipment can be reduced, and post-processing such as removing powder adhering to rubber molded products, as in the case of fluidized bed vulcanization using powder or heat medium, is possible. This greatly contributes to reducing equipment space, improving work efficiency, and improving product quality.

[Brief explanation of the drawing]

1 and 2 show cross sections of an embodiment of the device according to the present invention. FIG. 1 is a sectional view taken along the - line in FIG. 2, and FIG. 2 is a sectional view taken along the - line in FIG. 1. FIG. 3 is an enlarged view of the main part of FIG. 1. 1... Heating furnace, 2... Applicator, 5a...
Rubber molded product inlet, 5b...Rubber molded product outlet,
7... Waveguide, 8... Microwave oscillator, 10...
...Copper pipe, 11...High frequency oscillator, 13...Hot air generator, 14...Blow pipe.

Claims (1)

[Claims] 1 A waveguide of a microwave oscillator is opened in the applicator that constitutes a heating furnace for a rubber molded product with a cored metal, and a metal pipe connected to a high-frequency oscillator is buried in a coil shape in the circumferential direction in the peripheral wall of the applicator. A vulcanizing device for a rubber molded product containing a cored metal, characterized in that a microwave oscillator and a high-frequency oscillator are operated alternately for a predetermined period of time.