JPS62151238A - Control method for electric upsetter - Google Patents

Abstract

PURPOSE:To stabilize a shape of a product and a working time by calculating and adding a deviation against set values of a voltage value of a primary side of a current controllable transformer for an electric heating upsetter working, and a power and/or current value, and controlling a thyristor phase angle. CONSTITUTION:The vicinity of the end part of a base material 1 is held by a pressure 6 of an electrode 4 for electric conduction, the tip is made to abut on an anvil 5, the base material 1 is heated by an electric conduction of a secondary side 8 of a current controllable transformer 7 and pressed 2, 3 and it is brought to upsetter forging. In that case, a voltage value 13 and a power value 14 and/or a current value 15 of a primary side 9 are detected, and by a control circuit 16, a deviation value against the respective set values is calculated and added. A phase angle of a thyristor 11 being in the primary side is controlled by a phase control angle adjusting device 12 so that its added value becomes small. By this control, a variance of a forge contraction shape and a forging time of the product 1 is decreased, and by improving the quality and making a tact constant, the production efficiency is improved.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method of controlling an electrical upsetter.

(Prior art) An electric forge is generally used to forge a rod-shaped material by passing an electric current through it, heating and compressing the material as a preforming step prior to die forging. An example is shown. In the figure, 1 is a forged product, 2 and 3 are upper and lower compression cylinders, 4 is an electrode for energizing the material, 5 is an anvil, and 6 is a clamp cylinder for clamping the material. Further, 7 is a step-down transformer, the secondary winding 8 of which is connected to the voltage viA 4 and the anvil 5, and the secondary winding 9 of which is connected to the AC power source 10.

(Problem to be solved by the invention) However, in the above-mentioned conventional electric upsetter, the product 1
There was a problem in that the shape of the bulge portion 1a and the forging time varied greatly. Possible causes of these variations include variations in the pressurizing force of the upper and lower cylinders 2 J5 and 3, and fluctuations in the input electrical energy, but the pressurizing force of the cylinders is usually maintained at a relatively constant value. According to the inventor's findings, the greatest influence is due to fluctuations in the input electrical energy. That is, in the conventional electric generator, the step-up transformer 7 is directly connected to the AC power supply 10.
Since it has an open-loop electric circuit connected to -, the terminal voltage E of the -th winding 9 is directly affected by the voltage fluctuation of the AC power supply 10, as shown in Fig. 6 (a), and -
As shown in Figures (b) and (C), the power P and current ■ on the next side cause overshoot and undershoot phenomena due to the rush current at the start of energization in addition to fluctuations in the power supply voltage. As the temperature increases, it is forged and becomes thicker, so it increases and fluctuates over time. Such fluctuations in the input voltage, current, and power to the step-up transformer 7 cause variations in the temperature of the material during energization, the rate of temperature rise, etc. for each product, and this causes variations in the forging shape and forging time of the product. This is thought to cause variation.

This invention solves the above-mentioned conventional problems, and is an electric abrader that can reduce variations in the forged shape J5 and forging time of products by stabilizing the input electrical energy of the electric abrader through feedback. This paper attempts to provide a method for controlling leaf ivy.

(Means for Solving the Problems) In order to achieve the above object, in the method for controlling an electric turbine according to the present invention, a thyristor for power adjustment is connected to the primary side of the step-up transformer of the electric turbine. The voltage, power and/or current applied to the primary winding of the step-up transformer is detected, and the deviation between the detected voltage value and the voltage setting value and the detected value of the power and/or current are determined. Add each deviation of the power setting value and/or current setting value,
Phase control is performed using the obtained addition signal to adjust the phase control angle of the thyristor in a direction that reduces each of the deviations.

In this invention, the voltage, power, and current applied to the primary winding of the step-up transformer may be used as the parameters for controlling the input electrical energy of the electric aerator; Control with sufficient precision can be achieved by using either voltage or voltage, and according to the inventor's findings, it is most preferable to use voltage and power.

In addition, various patterns are adopted for the set values of voltage, power, and current19, but as shown in Figure 6, the state of change in power and current in the conventional device can be approximated by a straight line that increases with time. It is preferable to use a constant voltage as a set value, because each set value can be easily determined using data obtained by the conventional method, and control is also easy.

(Function) In the control method of the present invention, when the voltage, power, and/or current applied to the primary winding of the R diversion transformer increases or decreases and a deviation occurs with respect to each set value, an addition signal of each deviation value is generated. The phase of the thyristor provided on the primary side of the transformer is controlled, and each deviation value is reduced by adjusting the firing timing of the thyristor. This maintains the voltage, power, and/or current within a predetermined range for each set value during fluctuations, and equalizes the electrical energy for heating the material, resulting in variations in product forging time and shape. decreases.

(Embodiment) An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, the same parts as in FIG. 1 are given the same reference numerals. 1
1 is a power regulating thyristor connected to the primary side of the step-up transformer B7, and 12 is a phase control angle adjusting device for this thyristor. Further, 13 is a voltage sensor for detecting the voltage of the primary winding 9, 14 is a power sensor, and 15 is a current sensor. In this embodiment, the values detected by the voltage sensor 3 and the power sensor 14 are used as parameters, and the second The configuration is shown in FIG.
is a constant voltage setting that does not change over time IaE o
A voltage setting device 18 has a power setting value P that increases linearly with time from the time t 1 when energization starts to the time t 2 when energization ends. The power setters 19 and 20 are differential amplifiers that operate as comparators, and are configured to compare the voltage detected by the voltage sensor 13 with the voltage setting of the voltage setter 17! 1fiE
The difference signal S1 is compared and amplified by the differential amplification unit 19, and the difference signal S1 is inputted to the adder 21, and the power detection value by the power sensor 4 and the power set value P. are compared and amplified by the differential amplifier 20 and the resulting deviation signal S2 is input to the adder 21. The width difference signals S and S2 are weighted and added as necessary by an adder 21, and the added signal S3 is added to an amplifier 22.
After amplifying the voltage signal to a voltage signal suitable for feedback, the adder 23 generates a bias voltage.
4 bias voltage V. and phase control angle adjustment device 1.
2 as a control signal to control the phase of the thyristor 11 so as to adjust the phase control angle in a direction that reduces the voltage deviation and power deviation. As shown in FIG. 4, this phase control delays the firing timing of the thyristor 11 in an excessive input power state where the immersion voltage J3 and electric power are excessive, and delays the firing timing of the thyristor 11 in an insufficient input power state where the input power and voltage are insufficient. The ignition period 11) is advanced, and the ignition timing is constantly adjusted to correct deviations in voltage and power even in response to instantaneous fluctuations in voltage and power. Variations in the voltage and power applied to the product are suppressed to a small amount, and variations in the forged shape and forging time of the product are reduced.

Figures 3 (a) to (C) show the voltage E when the same product (engine valve) as in Figure 6 was forged using the above method;
It shows the state of change in electric power P and current I (values detected by the current sensor 15), and compared to Fig. 6, electric energy was input with less fluctuation, and good results were obtained with less variation in product forging shape and forging time. was gotten.

The present invention is not limited to the embodiments described above, and for example, a device having a configuration other than that described above may be used as the control device 16.

(Effects of the Invention) As explained above, according to the present invention, it is possible to reduce variations in the forged shape and forging time of products in an electric forge, improve product quality, and produce a forging line with a constant takt time. This contributes to improving efficiency.

[Brief explanation of drawings]

Fig. 1 is an equipment system diagram showing an example of the apparatus used in the method of the present invention, Fig. 2 is a circuit diagram of the control circuit shown in Fig. 1, and Figs. A diagram showing the relationship between voltage, power, current and time on the primary side of the step-up transformer in the device, Figure 4 is a comparative illustration of the method of this invention and the conventional method, and Figure 5 is an example of a conventional electric upsetter. The equipment system diagrams shown in FIGS. 6(a) to 6(C) are diagrams showing the relationship between voltage, power, current, and time on the primary side of the step-up transformer in the apparatus of FIG. 5. 7...Step-up transformer, 9...-second winding, 10...
AC power supply, 11... Thyristor, 12... Phase control angle adjustment device, 13... Voltage sensor, 14... Power sensor, 15... Current sensor, 16... Control circuit, 1
7... Voltage setting device, 18... Power setting device, 19...
・Differential amplifier, 20... Differential amplifier d] device, 21... Adder, 22... Amplifier, 23... Adder, 24...
・Bias voltage generator. Figure Start of page 3 (b) tw t2 Haruma Figure 4

Claims (1)

[Claims] 1. A thyristor for power adjustment is connected to the primary side of a step-up transformer of an electrical upsetter, and the voltage, power and/or current applied to the primary winding of the step-up transformer is detected. ,
The deviation between the detected voltage value and the voltage setting value, and the deviation between the detected power and/or current value and the power setting value and/or current setting value are added, and the resulting sum signal is used to A method for controlling an electric upsetter, comprising performing phase control to adjust the phase control angle of the thyristor in a direction that reduces deviation. 2 The voltage setting value is a constant voltage, and the power setting value and/or
2. The method of controlling an electric upsetter according to claim 1, wherein the current setting value is represented by a straight line increasing with time.