JPS6021472B2 - Temperature control device for induction heating equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a program-controlled temperature control device that performs arbitrary temperature rise control in an induction heating device.

As shown in FIG. 1, a conventional temperature program control method for an induction heating apparatus uses a power source 5 to make the deviation between the value T detected by the overflow detector 1 and the set value L programmed in the temperature program set value 3 to zero. A common control method is to control the power supplied from the induction heating coil 4 to the induction heating coil 4.

However, if there is a problem with the accuracy of the temperature detector 1, for example, when detecting temperature with a radiation thermometer, the heated material 2, which is the object to be measured, may
Depending on the surface condition and atmosphere, the detected value T may be low depending on the actual temperature To. Therefore, the deviation (T-L) from the set value L of the temperature program setter 3 becomes large, and the electric power is controlled to be increased, so that the actual temperature becomes higher than the set temperature. In order to prevent such problems from occurring,
In some cases, a method is used in which the power is programmed using the power program setting device 8 so as to obtain the required temperature rise as shown in Fig. 2. impractical because it is difficult to do so. In view of the above points, the present invention performs temperature program control using temperature feedback.

The object of the present invention is to provide a temperature control device for an induction heating device that can perform more stable temperature control by providing a device that assists in the instability of temperature detection in the device. An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 3, a power meter (KWH) 10 and T
, = Kx (power consumption KWH), the detected value T of the temperature sensor 1, and the output T of the converter 11 are input, and the low level selector 12 outputs whichever is larger. configured.

The temperature of the heated material 2 is generally proportional to the input (energy) to the heated material 2.

In reality, it is difficult to directly measure the input to the heated material 2, so the input to the heating coil 4 is measured and the input to the heated material 2 is measured.
temperature = (heating coil input KWH) x heating coil efficiency)
× (heat dissipation efficiency) × (surface temperature correction coefficient) / (specific heat) × (
It can be determined as the weight of the material to be heated).

That is, the temperature T of the heated material 2, = Kx (heating coil KWH
). However, by keeping the conversion ratio of the converter 11 variable, the conversion ratio of the converter 11 is variable. by K
need to be set.

In addition, since T, is used to back up the detected value of temperature sensor 1, for example, T, = (0.95 to 0.97).
Set K so that ×To. Therefore, temperature sensor 1
Even if the detected value T is lower than the actual temperature To, in that case, temperature control by temperature feedback can be performed normally using T and the set value n2 of the program setting device 3. As described above, according to the present invention, for example. In cases where it is necessary to raise the temperature to a certain degree, such as in roll wisteria inserting, stable temperature control can be performed using temperature feedback, thereby making it possible to prevent the production of defective products due to temperature control. Furthermore, it greatly contributes to improving productivity and improving productivity by preventing defects.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a conventional temperature control device, FIG. 2 is a block diagram showing a method of temperature control by power control, and FIG. 3 is a block diagram showing a temperature control method of the present invention. DESCRIPTION OF SYMBOLS 1... Temperature detector, 2... Heated material, 3... Temperature program setter, 4... Heating coil, 5... Induction heating power supply, 6, 7... Converter, 8... Turtle Powerful. gram setting device, 9... wattmeter, 10... wattmeter,
11...Converter, 12...Low level selector. 1st
Figure 2 Maple No. 34

Claims (1)

[Claims] 1. Equipped with a temperature detector that detects the temperature of the material to be heated inserted into the heating coil, and a temperature program setter that serves as a reference temperature to be compared with this detected temperature, the induction heating power is generated by the output of the temperature feedback control circuit. The temperature control device of the induction heating device to be adjusted includes a power meter that detects the integrated value of the input of the heating coil, a converter having a variable conversion coefficient such that T_1=K_x (power amount), and a converter of this converter. A temperature control device for an induction heating device consisting of a low level selector that takes the output and the output of a temperature detector as input, and outputs only the larger value.