JPS5952005B2 - Temperature raising method and device for extrusion press container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for increasing the temperature of a container for an extrusion press.

An extrusion press is provided with a container as a main component that houses a cylindrical raw material called a billet and into which an extrusion stem is fitted.

FIG. 1 shows a cross section of the main part of a typical container. The container 1 has a through hole 2 in the center into which a billet (not shown) is loaded, and the seven circumferential surfaces of the through hole 2 are is provided with a wear-resistant liner 3.

This liner 3 is provided on the inner surface of a cylindrical container tire 4, a heater 5 for heating is provided on the outside of the container tire 4, and a container holder 6 is further attached to the outside.

1 In a container having such a structure, a billet preheated to a predetermined temperature is supplied into the through hole 2, but the billet is kept warm by a heater 5 so that the temperature of the billet does not drop.

The temperature of the inner surface of the container 1 near the liner 3 by the heater 5 is approximately 450°C.

In a container having such a structure, the temperature at the outer peripheral portion where the heater 5 is provided is naturally high, and the temperature at the liner 2 side is low.

Therefore, when the temperature of the container is raised from room temperature to a predetermined temperature before starting up a dormant extrusion press, the temperature of the outer periphery rises quickly, and the temperature of the inner periphery rises relatively slowly. The temperature rises, but it does not rise as high as the temperature at the outer periphery.

Therefore, if current is continuously supplied to the heater 5 from the beginning, the temperature difference between the inner and outer circumferences of the container 1 will become too large relatively quickly, and for example, the temperature difference between the outer circumference and the inner circumference of the container 1 will be 100 degrees Celsius or more. If this happens, cracks may occur in the liner 3, container tire 4, and other parts due to a relatively large difference in thermal expansion.

The present invention was made to solve the above-mentioned problems, and is designed to prevent the temperature difference between the outer circumferential surface and the inner circumferential surface of the container from becoming so large as to cause cracks.
It is an object of the present invention to provide a method and apparatus for increasing the temperature of a container.

In the present invention, in order to achieve the above object, two thermocouples are provided to detect the outer circumference temperature and the inner circumference temperature of the container, respectively, and temperature control is activated based on the temperature difference between the outer circumference and the inner circumference of the container. Using a container device equipped with a meter, when the temperature difference between the inner and outer circumferences of the container reaches a predetermined minimum temperature difference,
Heating is performed by energizing the heater, and when the temperature difference between the inner and outer circumferences reaches a predetermined maximum temperature difference, the power supply to the heater is stopped and the temperature difference between the inner and outer circumferences of the container is always within the predetermined temperature difference range. We adopted a method and device that gradually increases the temperature of the container.

Next, the present invention will be explained in detail with reference to one embodiment shown in the drawings.

FIG. 2 is a circuit diagram illustrating one embodiment of the present invention, in which the reference numeral 10 indicates a first thermocouple for detecting the temperature of the outer circumference of the container 1;
A second thermocouple is shown for detecting the temperature of the inner circumferential portion of the.

Thermocouples 10.11 were mounted, for example, in the positions shown in FIG.

The temperature at the measurement point where the first thermocouple 10 is located is always higher than the temperature at the measurement point where the second thermocouple 11 is located because it is closer to the heating source.

12 is a 3-position control type temperature controller for preventing overheating of the outer periphery;
This temperature controller 12 measures the temperature between the outer circumferential temperature of the container 1 detected by the first thermocouple 10 and the inner circumferential temperature of the container 1 detected by the second thermocouple 11.

Operates by degree difference.

That is, when the temperature difference between the inner and outer circumferences reaches the preset maximum temperature difference α°C, a signal from the temperature controller 12 turns off the electromagnetic contactor 14, which will be described later, to reduce the temperature difference between the inner and outer circumferences. has reached the preset minimum temperature difference β.

At this time, the electromagnetic contactor 14 is turned on in response to a signal from the temperature controller 12, and is operated to activate the heater 5.

13 is a temperature controller with a pair of upper limit alarm contacts, for example, 500°C.
Set it to issue an alarm.

This means that when the temperature of container 1 reaches 600℃ or higher,
This was provided to prevent the hardening effect from being lost, and the electromagnetic contactor 14 is turned off when the temperature reaches the set temperature of the temperature controller 13.

one circuit of the first thermocouple 10 connected to the temperature controller 12;
That is, the contact 15a of the switch 15 is provided in the wiring 18 that connects the (-) terminals, and the (-) side comrades of the first and second thermocouples 10 and 11 are connected to the switch 1.
The contact 15C of the switch 15 is connected to the (-) side of the temperature controller 12 and the (+) side of the second thermocouple 11. The wires 17 are connected to each other by a wire 17.

Each of these contacts 15a, 15b, and 15C is operated in conjunction with one switch 15, and during normal extrusion press operation, the contact 15a is turned on, and the contacts 15b and 15C are both turned off, causing the temperature of the container 1 to rise. At times, the contact 15a is OFF and the contact 15b is OFF.

Both 15C were set to ON.

19 is a wiring breaker for wiring protection on which power supply voltage acts;
14 is turned on and off by signals from temperature controllers 12 and 13.
F is an electromagnetic contactor, 20 is a power regulator, and 5 is a heater, which are connected in series.

The power regulator 20, also called an SCR unit, is a device that continuously supplies and cuts voltage, changing the voltage to change the power.For example, when the temperature of the container 1 is low, it keeps the current flowing through it constant, and The internal temperature of 1 is 45
When the temperature approaches 0°C, the current flowing through this part is gradually reduced, and when the internal temperature reaches the set temperature of 450°C, the current flowing through this part is reduced to 0.

Next, the effects of this embodiment configured as described above will be explained.

As mentioned above, during normal operation in which the extrusion operation is performed, the contact 15a of the switch 15 is ON;
b, 15C is in the OFF state.

On the other hand, when trying to raise the temperature of the container 1, switch the contacts 15a, 15b, and 15C of the interlocking switch 15.
The state becomes N.

As a result, the difference between the outer peripheral temperature and the internal temperature of the container tire 4 is input to the temperature controller 12.

At this time, if the maximum set temperature difference is set to α°C and the minimum set temperature difference is set to β°C on the temperature controller 12, the temperature difference between the outer circumference and the inside of the container tire 4 will be the maximum set temperature difference α°C. Then,
The supplied current is cut off, and then, when the temperature difference between the inner and outer circumferences of the container 1 reaches the minimum set temperature difference β°C, the current is supplied again, and heating is performed again until the maximum set temperature difference α°C is reached.

By such a heating method, the container 1 is gradually heated.

An example of the temperature raising process at this time is shown in FIG. In FIG. 3, the horizontal axis represents time t, and the vertical axis represents temperature T.

In this case, the set maximum temperature difference α was about 85°C, and the set minimum temperature difference β was about 50°C.

- On the other hand, a detection signal of the internal temperature of the container 1 is input to the second thermocouple 11.

Therefore, when the temperature of the container 1 is raised to the final set target temperature, the temperature of the container 1 is controlled by the temperature controller 13 provided on the second thermocouple 11 side, and is maintained at a constant temperature.

If the above-mentioned method of the present invention is adopted, two temperature controllers 12.13 will be connected to one thermocouple, but since the impedance of the temperature controller is generally 10 OKΩ or more, it is not practical even if two are connected. There is nothing wrong with the top.

As is clear from the above description, according to the present invention, it is possible to raise the temperature of the container while controlling the temperature difference between the outer circumference and the inner circumference of the container to always be within a certain range. This has the excellent effect of allowing the container to be heated to a predetermined temperature from the shoulder side without causing cracks or the like in the component parts of the container due to differences in thermal expansion due to temperature differences.

[Brief explanation of the drawing]

The drawings show one embodiment of the apparatus used to carry out the method of the present invention, in which Fig. 1 is a longitudinal sectional view explaining the structure of a general container, Fig. 2 is an electric circuit diagram, and Fig. 3 is a diagram of the present invention. FIG. 3 is a diagram showing an example of a temperature rising state according to the method of the invention. 1...Container, 3...Liner, 4.
・Curved container tire, 5... Heater, 10.1
1... Surface thermocouple, 12, 13... Temperature controller, 14
・Song・Magnetic contactor, 15...Switch, 15a
, 15b, 15C... contacts.

Claims (1)

[Claims] 1. Equipped with two thermocouples that detect the temperature at the outer circumference and the temperature at the inner circumference of the container, respectively, and a temperature controller that operates based on the temperature difference between the temperature at the outer circumference and the temperature at the inner circumference of the container. Using a container device, when the temperature difference between the inner and outer circumferences of the container reaches a predetermined minimum temperature difference, the heater provided in the container is energized, and when the temperature difference reaches the predetermined maximum temperature difference, the heater is turned on. A method for raising the temperature of a container for extrusion presses, in which the temperature of the container is raised while stopping the supply of electricity to the container. 2. A first thermocouple for detecting temperature at the outer circumference provided on the outer circumference of a container for extrusion press having a heater on the outer circumference, and a second thermocouple for detecting temperature at the inner circumference provided at the inner circumference of the container. , with their respective homopolar contacts connected, are connected in series to a temperature controller that sets the temperature difference between the inner and outer periphery of the container detected by these thermocouples within a predetermined range between the maximum temperature difference and the minimum temperature difference. and a changeover switch is provided in this electrical wiring for detecting the temperature at the outer circumference and for detecting the temperature difference between the inner and outer circumferences, and when the maximum temperature difference and the minimum temperature difference determined by the temperature controller are reached. , a temperature raising device for an extrusion press container equipped with an electromagnetic contactor that cuts off and energizes the supply of current to a heater installed on the outer periphery of the container.