JPS63299080A - Safety device for high-frequency heating device - Google Patents

Abstract

PURPOSE:To obtain the reliable operation in any environment by reading the value of a temperature detecting means detecting the temperature in a heating chamber when the preset time elapses after the start of cooking. CONSTITUTION:A heating chamber 1 storing a heated object, a high-frequency generator 4 heating the heated object, a temperature detecting means 11 provided at the exhaust port section 10 in the heating chamber 1, and a control means 3 controlling the high-frequency heater 4 are provided, and the control means 3 stops the operation of the high-frequency heater 4 based on the value of the temperature detecting means 11 when the preset time elapses after the start of cooking. Since the failure of the temperature detecting means 11 is detected based on the value of the temperature detecting means 11 when the preset time elapses after the start of cooking, it can be operated in the low- temperature environment. The normal operation can be thereby obtained in any environment.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention provides a safety device for a high-frequency heating device, which is equipped with a temperature detection means for detecting the temperature inside the heating chamber in the high-frequency heating device, and has a function of detecting ignition, smoke generation, etc. It is related to.

BACKGROUND OF THE INVENTION Conventionally, the safety device for this type of high-frequency heating device has been to cut off the power supply to the high-frequency heating device when the temperature exceeds a certain predetermined temperature using a mechanical temperature switch provided in the high-frequency generator.

For example, FIG. 3 shows a safety device circuit diagram of a conventional high-frequency heating device. 16 is a commercial power supply, and 18 is a temperature switch attached to the above-mentioned high-frequency generator.The contact is closed when the temperature is below a certain predetermined temperature, and the contact is opened when the temperature exceeds a certain predetermined temperature.

Power is supplied to the control means 3 for controlling the high-frequency heating device and the high-frequency generator 4 through the contacts of this temperature switch. It is configured to supply power to the high voltage transformer 6. Therefore, the configuration has been such that an abnormal temperature of the high-frequency generator can be detected, the power supply to the high-frequency heating device can be cut off, and the operation can be stopped.

Further, FIG. 4 is a configuration diagram of a safety device that includes a temperature detection means in the exhaust hole of the high-frequency heating device and detects abnormal temperature inside the heating chamber. The object to be heated 2 placed in the heating chamber 1 is heated by high frequency waves generated from the high frequency generator 4 .

Also, the high frequency is radiated from the antenna 6 and stirred by the stirring blade 7.
is uniformly supplied to the heating chamber 1. The blower mechanism 8 is supplied to the heating chamber 1 through an inlet 9 . When high frequency waves are supplied to the heating chamber 1, the temperatures of the heating chamber wall surface and the object to be heated 2 rise, and accordingly, the exhaust temperature also rises. Therefore, the temperature inside the heating chamber 1 can be detected by the temperature detecting means 11 provided near the exhaust port 1o of the heating chamber 1. The detected signal is transmitted via the signal line 12 to the control means 3 that controls the high frequency heating device.

If the temperature is above a predetermined temperature, the control means 3 stops the high frequency generator 4 via the signal line 14 and also stops the operation of the high frequency heating device. Further, as a detection of a disconnection of a signal line or an open failure of the temperature detection means, if the temperature detection means falls below a certain predetermined temperature, it is regarded as a failure.

FIG. 6 shows the characteristics of the temperature detection means and also shows the detection method. The horizontal axis shows temperature, and the vertical axis shows resistance value. When the temperature is low, the resistance value increases to several hundred kilohms. Furthermore, when the temperature is high, the resistance value is small and becomes several kilohms. T& indicates abnormal temperature and becomes the resistance value of RIL. At this time, the operation of the high-frequency heating device is stopped. Conversely, Tb indicates the temperature at which an open failure of the temperature detection means is detected,
It shows the resistance value of Rb. Rb is several hundred kilohms.

Problems to be Solved by the Invention However, in the above configuration, the detection resistance value for open failure of the temperature detection means is fixed to Rb, so the high frequency heating device cannot be used in an environment below Tb. It had

The present invention is intended to solve these conventional problems, and aims to ensure failure detection of the temperature detection means and to operate normally under any environment.

Means for Solving the Problems In order to solve the above problems, the safety device of the high frequency heating device of the present invention includes a heating chamber for storing the object to be heated, a high frequency generator for heating the object to be heated, and a heating chamber for storing the object to be heated. The control means stops the operation of the high-frequency heating device depending on the value of the temperature detection means after a predetermined period of time has elapsed after the start of cooking. It has a detection section that allows

According to the above-described structure, the present invention detects failure of the temperature detecting means based on the value of the temperature detecting means after a predetermined period of time has elapsed after the start of cooking. Therefore, the present invention can be operated in a low temperature environment. be.

Example Embodiments of the present invention will be described below based on the accompanying drawings.

FIG. 1 shows an embodiment of the present invention, in which an object to be heated 2 placed in a heating chamber 1 is heated by high frequency waves generated from a high frequency generator 4. In FIG. Further, the high frequency is radiated from the antenna 6 and uniformly supplied to the heating chamber 1 by the stirring blade 7. The blower mechanism 8 is supplied to the processing chamber 1 through an inlet 9. When high frequency waves are supplied to the heating chamber 1, the temperature of the heating chamber wall surface and the object to be heated 2 rises, and the temperature of the exhaust gas from the exhaust port 1o rises accordingly. Therefore, the exhaust port 1 of the heating chamber 1
The temperature inside the heating chamber can be detected by the temperature detection means 11 provided near zero. The detected signal is transferred via the signal line 12 to the control means 3 that controls the high frequency heating device. The control means 3 includes a detection section 13 that determines whether the temperature detected by the temperature detection means after a predetermined time has elapsed after the start of cooking has reached a predetermined temperature, and detects a disconnection if the temperature has not reached a predetermined temperature. Further, as in the conventional example, in response to an abnormal temperature rise due to combustion of the object to be heated in the heating chamber, the high frequency generator 4 is stopped via the signal line 14, and the operation of the high frequency heating device is also stopped.

Next, a method for detecting failure of the temperature detecting means will be explained using the timing chart of FIG. T where the ambient temperature is very low.

When cooking is started in vIL (To〈Tb), conventionally,
Although the temperature detection means was inoperable due to a failure, the value of the temperature detection means was read and judged after a predetermined period of time (T,) after the start of cooking.

According to this configuration, since the value (temperature) of the temperature detection means is checked after a predetermined elapsed time after the start of cooking, a failure of the temperature detection means can be reliably detected under any environment, regardless of the surrounding environment. Moreover, a high frequency heating device can be operated.

Effects of the Invention As described above, according to the safety device of the high frequency heating device of the present invention, the following effects can be obtained.

Since the value of the temperature detection means that detects the temperature inside the heating chamber is read after a predetermined time has elapsed after the start of cooking, there is no possibility of mistaken recognition that the temperature detection means is malfunctioning in low-temperature environments, and it can be used reliably under any environment. This has the effect of enabling accurate detection.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a timing chart showing the detection timing of the temperature detection means, FIG. 3 is a circuit diagram of a conventional example, FIG. 4 is a sectional view of the same, and FIG. It is a characteristic diagram of a general temperature detection means. 1... Heating chamber, 3... Control means, 4.
...High frequency generator, 1o...Exhaust port section, 11...Temperature detection means, 13...Detection section. /-m-Heating 1 3---11iII! Machiko role 4-11 Island use main table 1 10--1 exhaust port/l--1 Boneyu Kenba pot role 2 figure 3rM figure 4 figure 5

Claims (1)

[Claims] A heating chamber for storing an object to be heated, a high frequency generation device for heating the object to be heated, a temperature detection means provided at an exhaust port of the heating chamber, and a control means for controlling the high frequency heating device, the control means The present invention is a safety device for a high-frequency heating device, which includes a detection section that stops the operation of the high-frequency heating device based on the value of the temperature detection device after a predetermined period of time has elapsed after the start of cooking.