JPS5823715B2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] The present invention detects the temperature of the food by touching or inserting it into the food in the heating chamber, transmits this without going through a transmission line, and uses high frequency heating waves as the transmission power source. The present invention relates to a high-frequency heating device having a container.

BACKGROUND ART Various temperature detectors that detect temperature by contacting or inserting food have been developed, and among them, temperature detectors that control the operation of a high-frequency oscillator wirelessly without using a transmission line have also been devised.

The advantages of this temperature sensor that does not use a transmission line include that it is easier to handle and clean than conventional ones, and that food can be placed on a turntable and rotated.

However, this temperature sensor requires a transmitter and a power source for the transmitter.

The transmission power required for the transmitter varies depending on the required S/N and antenna efficiency, and if the external size of such a temperature detector becomes large, the above-mentioned effect will not be utilized, so the antenna must be sufficiently large. efficiency is reduced.

For these reasons, the power consumption of the transmitter increases, and if a battery is used as a power source, it will consume too much energy and cannot withstand long-term use. Therefore, it is proposed to rectify the high frequency for heating and use it as a power source. has been done.

This method eliminates the need for a power switch and has the advantage of not emitting interference radio waves to other devices when taken out of the heating chamber. However, the distribution of high frequencies inside the heating chamber is complex, and the antenna The electromotive force induced in the antenna changes by several tens of times depending on the high-frequency output power, the amount of load, the position of the antenna, movement of the antenna with a turntable, stirring with a stirrer fan, etc.

It is difficult to constantly supply stable power to the transmitter from the induced power of the antenna, which changes in this way.
In the present invention, the electric charge obtained by rectifying the heating high frequency wave is stored in a tank circuit, and a signal is transmitted to control the high frequency heating device only when the transmitter is operable.

This method does not require a large-capacity tank circuit, making the temperature detector compact and inexpensive, and also allows the transmitter to operate stably even in the unstable electric field strength distribution inside the heating chamber. One embodiment of the present invention, which can be easily realized, will be described below with reference to the drawings.

In Figure 1, 1 is a temperature setting dial for setting the heating temperature of food, 2 is a cooking time setting dial, 3 is a cooking switch, 4 is a menu dial, 5 is a heating cabinet, 6 is a temperature detector, and 7 is a turntable. , 8 is food.

When only the cooking time setting dial 2 is set, the operation of this high-frequency heating device is as follows: When only the cooking time setting dial 2 is set, cooking is performed according to the time, and when only the temperature setting dial 1 is set, the food 8 reaches the set temperature. Cooking ends.

In addition, when temperature setting dial 1 and cooking time setting dial 2 are set at the same time, the high frequency output is turned on and off from the moment the food 8 reaches the set temperature to keep the food 8 temperature constant and set the cooking time. Cooking ends when the time elapses.

However, if the high frequency output is completely stopped when turned off, there will be no power supplied to the temperature detector 6, so the configuration is such that the high frequency output of several tens of watts is constantly oscillated.

FIG. 2 is a block diagram showing the configuration of a high-frequency heating device, in which an antenna 20 receives high-frequency waves for heating, a tank circuit 21 provided in an electronic circuit 25 shown in FIG. 3 rectifies and smooths the high-frequency waves, and stores the waves. Additionally, it is used as a power source for the transmitter 11.

A preamplifier 10 converts the signal obtained from the heat-sensitive element 9 into a modulated signal, and a carrier wave oscillated by a transmitter 11 and a signal modulated by a modulation circuit 12 are transmitted from a transmitting antenna 13.

This signal is then received by the receiving antenna 14 and sent via the tuning circuit 15 and demodulation circuit 16 to the control device 18 provided between the power supply section 17 and the heating high-frequency oscillator 19.

The tank circuit 21 is composed of a high-frequency diode and an electrolytic capacitor, and is a simple circuit that operates only when a high induced electromotive force is generated in the antenna 20, but it is rotated by the turntable 7 and stirred by the electric field by the stirrer. Therefore, it is configured to always operate once every few seconds.

Furthermore, the tank circuit 21 is a voltage comparator circuit with hysteresis like a Schmitt trigger circuit, which detects the voltage charged in the electrolytic capacitor and operates the transmitter 11 only during a predetermined voltage. Stable oscillation can be performed.

For the temperature detector 6 that oscillates intermittently in this way, the control device 18 on the receiver side is provided with a delay circuit for several seconds, and even when not receiving data, the high frequency oscillator 19 is turned on or off for several seconds. Only when a signal is received, the high frequency oscillator 19 is controlled from on to off or from off to on.

That is, the configuration also serves as a safety circuit that senses an abnormality and stops the operation of the high frequency oscillator 19 when no signal is received for a predetermined period of time or more.

FIG. 3 is a cross-sectional view showing the configuration of the temperature detector 6. The heat-sensitive part 22 and the main body 23 are electrically separated, and mechanically connected through an insulator 24 from the outside. Ori,
A choke structure is formed at the connection part.

The signal obtained from the heat-sensitive element 9 provided in the heat-sensitive section 22 is modulated into a carrier wave in the electronic circuit 25, and the heat-sensitive section 22
is transmitted to the outside using the main body 23 as the ground side and the antenna side as the main body 23.

As mentioned above, the power supply to the electronic circuit 25 is provided by the antenna 2.
This is done by receiving a high frequency heating wave at 0, rectifying it with a high frequency diode 26, and storing electric charge in a tank circuit 21 provided in an electronic circuit 25.

27 is a resin cap that protects the antenna 20.

The power source of the transmitter provided in the temperature detector of the present invention receives high frequency heating waves with an antenna, rectifies them, stores the obtained charge in a tank circuit, and the charging voltage of this tank circuit is higher than a predetermined voltage. Since the transmitter is configured to operate only when , the transmitted signal is stable and the operation of the high frequency oscillator can be accurately controlled via the control device.

[Brief explanation of the drawing]

FIG. 1 is an external view of a high-frequency heating device showing an embodiment of the present invention, FIG. 2 is a block diagram showing the configuration of the same high-frequency heating device, and FIG. 3 is a cross-sectional view of a temperature detector of the same essential part. . 6... Temperature detector, 11... Transmitter,
18... Antibacterial device, 19... High frequency oscillator, 20... Antenna, 21... Tank circuit, 25... Electronic circuit.

Claims (1)

[Claims] 1. Food that comes into contact with or is inserted into food in a heating chamber. A temperature detector that detects temperature, a transmitter that transmits an output signal of the temperature detector as a modulation signal, and a control device that receives the signal from the transmitter and controls the operation of the high-frequency oscillator. The transmitter's power source receives high-frequency heating waves using an antenna and rectifies them. The high-frequency heating device is configured to store the electric charge obtained in the tank circuit in a tank circuit, and to operate the transmitter only when the charging voltage of the tank circuit is equal to or higher than a predetermined voltage.