JPS5844126B2 - Induction hardening equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an induction hardening device, and more particularly to a protection device for preventing the flow of personnel who are not properly hardened.

The induction hardening equipment installed in the automatic line performs induction hardening on the personnel sent in from the previous process, and after the hardening is complete, they are automatically transferred to the subsequent process.

Loading, hardening, and unloading of the personnel to be burned are performed in a series, and this is performed continuously as a cycle.

When performing moving hardening on the human body to be burned, the feeding speed and input power are changed according to a program according to the shape of the human body to be burned.

If there is an abnormality in the feed speed or power during quenching, quenching will not be done properly and defective quenched material will flow to the subsequent process, so it is important to prevent such consequences as much as possible. Must be.

In general, the phenomenon of abnormal hardening is caused by poor contact in the circuit, partial failure to heat during programmed hardening, temporary stoppage of feed, malfunction of the detector for program commands (e.g. dog). This occurs when power and speed transformation is incomplete, or when the feed speed fluctuates due to extreme load fluctuations in the feed mechanism.

In order to detect this, there have been methods such as monitoring each electric power and feed speed, but it has not been possible to completely detect the abnormality.

This invention has been made in view of the above points, and has been made with attention to these points for the purpose of preventing abnormal quenching.

This method utilizes the fact that the above abnormal phenomena can be detected in most cases by monitoring the total amount of input power during programmed hardening during cycle operation.

In order to know the input power amount, since the power during hardening is proportional to the square of the output voltage, it is sufficient to monitor the integral value of the output voltage over time.

The output voltage is picked up using a voltage detector (instrument transformer), connected to a V/F converter, converted into a frequency, and integrated by a counter.

By looking at this integrated value, it is possible to know the input power amount.

If the integrated value during one cycle of quenching exceeds the preset lower limit and upper limit range, it will be output as an alarm.
Stop the induction hardening equipment during cycle operation.

This method can be constructed at low cost and can be said to be an extremely effective means.

FIG. 1 is a block diagram of a detection device used in the induction hardening apparatus of the present invention.
D is picked up by the AC/DC converter 6.
C is converted into a minute voltage and input to the V/F converter 7.

A counter 8 counts the integrated value of the voltage output from the V/F converter 7.

This count amount Cx and the lower limit setter 9 and upper limit setter 1
Amount CA set at 0.

CB is compared with the comparator 11, and when the range of the upper and lower limit set values is exceeded, an alarm output Ry is taken out and the device is stopped.

The input power amount WH is expressed by the following formula.

However, EX is the output voltage, be.

Output CX of counter 8 t is time, teeth is a constant The following equation is obtained from equations (1) and (2).

It is clear from equation (3) that the input power amount can be determined from the integrated count amount.

FIG. 2 is a diagram on the time axis when one cycle of programmed hardening is performed.
) is (tt to), and the output voltage EX applied to the inductor from the power supply during this period is E
It is converted from 1 to E5.

This time integral value can be known from the CX, and the CX at the quenching completion point (from power ON to OFF) is compared with the values CA and CB of the upper and lower limit setters.

A detection signal is sent at the quenching completion point t1, and a comparison function is provided when this signal is input.

After comparison detection, the count amount CX is returned to O by a reset signal for cycle detection (.

The upper and lower limit setting values are the cycle average value (
It is desirable to set this value to about ±5% of the standard value.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a detection device used in the induction hardening apparatus of the present invention, and FIG. 2 is a diagram of time and output voltage showing operating characteristics. DESCRIPTION OF SYMBOLS 1...-power supply device, 2...matching device constituted by a capacitor matching transformer, 3...inductor, 4...material to be quenched, 5 ...Instrument transformer, 6...AC/DC converter, 7
...V/F converter, 8... Integration counter, 9... Lower limit setter, 10...
Upper limit setter, 11...-Comparison device.

Claims (1)

[Claims] 1 V/F is connected to the input side of the inductor for heating and hardening, that is, the output side of the high frequency power supply device, via an output voltage detector.
A converter and a counter are installed to calculate the amount of electricity input during heating during cycle operation in terms of voltage, and issue an alarm signal if the amount exceeds or falls short of a predetermined amount. An induction hardening device that prevents the product from flowing when the product is heated.