JPS60254590A - High frequency heating device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an overtemperature rise protection circuit for a stationary high frequency heater.

Conventional configurations and their problems In recent residential environments, kitchen space has become narrower, and effective use of kitchen space has been discussed.

In line with this trend, complex high-frequency heaters such as installed types and hanging types have been developed. However, even the installed type, hanging type, and combination type are often used in conjunction with or combined with other cooking equipment, such as gas stoves or electric ovens, and it is only necessary to ensure the safety performance of the high-frequency heater alone. I can no longer say that. In particular, when used in conjunction with other cooking appliances, it was necessary to consider the combination conditions.

For example, in a conventional hanging type high-frequency heater, when the stove installed below is used, the internal temperature of the high-frequency heater rises, and the rM IL rises inside the heater. electronic components installed in.

This creates a situation where the safety performance of the structure cannot be ensured.

Therefore, we have a system in which a temperature sensor is provided on the bottom or the like, and a separately provided blower is operated by the operation of the temperature sensor, as shown in FIG. 5a.

In the conventional circuit configuration shown in b, for example, in Fig. 6a, when the temperature sensor is activated, it changes depending on the operating setting (strong operation/weak operation) of the blower, and when an abnormal temperature rise occurs, a prompt response is required. It has the disadvantage that it cannot be removed, and the fifth
In the conventional example shown in the figure, the blower always operates under strong operation, but the circuit configuration is complicated, two temperature sensors need to be provided, and the cost is high.

OBJECTS OF THE INVENTION Therefore, the present invention is intended to eliminate the above-mentioned conventional drawbacks, and aims to ensure safety performance by responding to installation conditions and temperature rises in the external environment.

Structure of the Invention In order to achieve the above object, the high frequency heater of the present invention has two features.
A cooling fan with stepped capacities (strong and weak modes) is installed, and the capacity can be switched manually. In addition, in the event of an abnormality, a temperature sensor installed on the exterior detects external temperature changes and forces the cooling fan to operate in high mode.
This has the effect of suppressing the temperature rise inside the high-frequency heater and ensuring safety performance.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance and installed state of the present invention. 1
is the main body of the high-frequency heater, and inside this main body 1 is a heating chamber 2.
is provided. A front opening of the heating chamber 2 is provided with a door 3 that can be opened and closed in order to take out and take out the food in the heating chamber 2.

On the front side of the main body 1, an operating section 4 is provided for displaying and controlling settings such as cooking time output. The main body 1 is provided above the stove 5 as shown in FIG.
An outside light 6 that illuminates the top surface of the stove 6 and a blower 7 that absorbs and exhausts hot air generated from the stove 5 are provided.

Hot air sucked in and exhausted from the blower 7 passes through a ventilation passage 8 provided on the rear surface of the main body 1 and is exhausted from the upper surface of the main body 1.

The lamp 6 and the blower 7 can be operated manually by pressing keys provided on the operating section 4. The lamp 6 turns on and off, and the blower 7
In this case, starting, weak operation, strong operation, and stopping can be performed.

In addition, a temperature sensor 9 is provided on the bottom of the main body 1, which detects an excessive temperature rise on the bottom of the main body 1 and operates the blower 7 to remove the hot air at the bottom or the hot air stagnant inside the main body. is discharged to the outside through the exhaust passage 8, thereby suppressing an excessive temperature rise on the bottom surface and inside the main body.

FIG. 3 shows a circuit diagram of the above configuration.

An intermediate tap is provided in the middle of the coil of the blower γ, and the configuration is configured so that it can be switched between using the entire coil RO (weak capacity) and using half the coil R1 with the intermediate tap (strong capacity). All the coils RO and the power relay 11 are arranged in series, and the power relay 12 has a normally open type and a normally closed type contact. Connect in series with the L contact. On the other hand, the normally open side contact of the power relay 12 is connected to the intermediate tap A of the blower 7. A normally open temperature sensor 9 provided at the bottom of the main body 1 is provided on the circuit of the coil of the power relay 12.

The effects of the above configuration will be explained below.
In the stopped state, power relays 11 and 12 are both OFF.
However, the power supply circuit to the blower 7 is open, and the blower 7id does not start.Next, press the key 14 on the operation panel 4 to select 1.
When tapped, it is input to CPU 13 and power relay 1
1 is turned on, power is supplied to all coils RO of the blower 7, and the blower 7 performs a low capacity operation. Next, when one more tap is made, further input is made to the CPU 13, turning off the power relay 11 and turning on the power relay 12, power is supplied to the intermediate tap A of the blower 7, and the blower 7 performs high-power operation. If you tap one more time, power relay 1 will be activated.
2 is OFF L, returning to the stopped state.

Now, when the bottom stove 5 of the main body 1 is activated, the temperature inside the main body 1 and the bottom of the main body 1 rises, the temperature sensor 9 senses it, and the normally open contact of the temperature sensor 9 closes. Regardless of the operating status, the power relay 12 is turned on, power is supplied to the intermediate tap A of the blower 7, the blower 7 performs high-power operation, and the hot air inside the main body 1 and the hot air outside the main body 1 are discharged through the exhaust passage 8. , to the outside of the main body 1 to lower the temperature inside the main body 1.

When the temperature at the bottom of the main body 1 becomes low, the temperature sensor 9 is opened, the power supply of the power relay 12 is opened, and the set operating condition is returned.

As described above, according to this embodiment, by detecting an abnormal temperature rise within the main body 1, the blower 7 is driven even when the blower is in operation, such as when it is stopped or in weak operation. It can be operated at the maximum capacity of 7, and the main body 1
This has the effect of suppressing the temperature rise inside the tank. Furthermore, the capacity switching circuit of the blower 7 is also formed as an independent circuit, so even when the temperature sensor 9 is activated, a closed circuit including the blower 7 is not formed, and an abnormality in the blower 7 itself is detected. Can prevent temperature rise, blower 7
Safety such as insulation ability and ventilation ability can be ensured. or,
Only one temperature sensor 9 is required, and there is no need to worry about malfunctions or abnormal phenomena due to variations in the sensed temperature when multiple sensors are installed.Furthermore, since it is installed on the auxiliary circuit, it can be of a low current type, reducing costs. It also has the effect of being effective.

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) When the temperature sensor detects an abnormal temperature, the blower can be operated at its maximum capacity regardless of the operating status of the blower (stopped or weakly operating), and the blower can be operated at its maximum capacity immediately. , abnormal temperature rises can be suppressed and the reliability and safety of each component installed within the main body can be ensured.

(2) In the blower capacity switching circuit, the circuits for each capacity form independent circuits, so the operation of the temperature sensor forms a self-closed circuit that includes the blower capacity switching circuit. There is no need to worry about this, and it is possible to prevent abnormal temperature rises in the blower itself, and also to allow the blower to demonstrate its maximum capacity.

(3) Only one temperature detector is required, so there is no need to worry about malfunctions or abnormal phenomena due to variations in detected temperature when multiple temperature detectors are installed, and since it is installed on the auxiliary circuit, one with a small rating can be used. It is possible to provide low-cost safety equipment.

[Brief explanation of drawings]

Fig. 1 is an installation diagram showing an embodiment of the present invention, Fig. 2 is a cross-sectional view of the structure of the embodiment, Fig. 3 is a circuit diagram of the embodiment, Fig. 4 is a control flow diagram of the same, and Fig. 6 is a circuit configuration diagram of a conventional example. 1...Main body, 4...Operation unit, 7...
・Blower, 9... Temperature detector, 10, 11.12
...Nokuwa Relay, 13...Cpuo Name of agent Patent attorney Toshio Nakao and 1 other person 1st
Figure 2 Figure 3 Figure 4 Figure 5 (α2

Claims (1)

[Claims] A blower with a capacity switching function and a normally open/air blower that switches this.
An electromagnetic switch having a normally closed contact, an electromagnetic switch having a normally open contact, and a temperature sensor are provided, the blower and the electromagnetic switch having a normally open contact are arranged in series, and the remaining electromagnetic switch is In a configuration in which the normally closed contact side is arranged in series, and the other normally open contact and the blower are arranged in series, the above temperature sensor is provided on the power circuit of the electromagnetic switch having both contacts. high frequency heating device.