JPH0285612A - High-frequency heater provided with piezo-electric element sensor - Google Patents

Abstract

PURPOSE:To obtain a fixed finished state of cooking by detecting a heating state of food with simple constitution, by making the title device into constitution where it possesses a slit in the vicinity of a steam hole and a piezo-electric element sensor is mounted behind the foregoing slit. CONSTITUTION:Output of a piezo-electric element sensor 1 is applied to a controller 7 and an electric power source of an electric wave irradiating part 8 and cooling fan 9 is turned ON/OFF by a signal of the controller 7. A material 10 to be cooked is arranged within a heating chamber 2 and a part 11 of a cooling air of the electric wave irradiating part 8 is led into the heating chamber 2 by the cooling fan 9. The part 11 of the cooling air and water vapor or oil 12 generated through the material 10 to be cooked are sent out from the heating chamber 2 through a discharge port 13. A part 5 of boiling steam passes through a steam hole 4 and abuts against a piezo-electric sensor 1 through a hole 15 of a slit 6. It does not happen that the oil or the steam or a burst matter of a part of food hits directly the piezo-electric element sensor 1 due to deviation.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a high-frequency heating device using a piezoelectric sensor that detects and controls the state of gas generated from food as the food is heated.

2. Description of the Related Art A detection means in a conventional high-frequency heating device will be explained with reference to the drawings.

FIG. 5 shows a conventionally used high frequency heating device with a humidity sensor. In the case of a humidity sensor, the moisture in the food boils and the humidity rapidly changes from decreasing to increasing, so by detecting this point it is possible to determine the end of cooking. Based on this, as shown in FIG.
The device is controlled by detecting the change in the resistance value of 2 by dividing the voltage of the reference voltage power source 23 with the resistor 24. (
For example, Japanese Patent Application Laid-Open No. 53-77365) Furthermore, as shown in FIG. 6, there is a method of using a piezoelectric element sensor instead of the humidity sensor. Heat is exchanged between the piezoelectric element sensor 1 and water vapor, and the thermal change generates a polarization current, which is detected to control the device. (
(For example, Japanese Patent Application Laid-Open No. 62-37624) Problems to be Solved by the Invention However, when a humidity sensor is used as described above, gas or oil in the food adheres to the humidity sensor during cooking, reducing detection sensitivity. Therefore, it is necessary to evaporate the deposits on the humidity sensor using a heater for refresh heat treatment or the like after each cooking cycle, resulting in the problem of extra power and cost.

There is also a method of using a piezoelectric element sensor instead of a humidity sensor, but since the piezoelectric element sensor was conventionally installed directly near the steam hole, not only oil and water vapor but also part of the food could explode. They had the drawback of flying and hitting the piezoelectric sensor directly, causing false detection and premature disconnection.

The present invention is intended to solve such conventional problems, and an object of the present invention is to detect the heating state of food with a simple configuration and provide a constant cooking finish state.

Means for Solving the Problems In order to solve the above problems, the high-frequency heating device with a piezoelectric element sensor of the present invention includes a heating chamber in which a food to be cooked is stored, and a heating chamber that radiates electromagnetic waves to the food to cook. a piezoelectric element sensor that detects the boiling state of the food to be cooked; a steam hole provided in the heating chamber; a slit near the steam hole; and a piezoelectric element sensor installed after the slit. It is configured to do this.

Function: As described above, the present invention has a slit between the steam hole and the piezoelectric element sensor, so that oil, water vapor, and objects that have blown out from a piece of food can be absorbed by the piezoelectric element. It has the effect of accurately detecting the boiling state of the food to be cooked with a simple configuration without directly hitting the element sensor.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings.

FIG. 1 shows a high-frequency heating device with a piezoelectric element sensor showing one embodiment of the present invention. The piezoelectric element sensor 1 is attached to the upper part of the steam hole 4 on the top plate 3 of the heating chamber, and a part of the boiling steam 5 passes through the steam hole 4 and reaches the piezoelectric element sensor 1 via a slit 6. It has become. The output of the piezoelectric element sensor 1 enters the controller 7, and the signal from the controller 7 sends the radio wave emitting part 8.
The power of the cooling fan 9 is turned 0N10FF.

A food to be cooked 10 is placed in the heating chamber 2 , and a portion 11 of the cooling air from the radio wave emitting section 8 is guided into the heating chamber 2 by a cooling fan 9 . A portion of the cooling air 11 and water vapor, oil, etc. 12 generated from the food to be cooked are sent out from the heating chamber 2 through the exhaust port 13.

FIG. 2 shows an example of a specific configuration showing the positional relationship between the steam hole 4, the slit 6, and the piezoelectric element sensor 1. The piezoelectric sensor 1 is mounted on the heating chamber top plate 3 using a mounting jig 14. A portion 5 of the boiling steam passes through the steam hole 4 and hits the piezoelectric element sensor 1 via the hole 15 of the slit 6. Due to the misalignment of the steam hole 5 and the slit hole 15, oil, water vapor, some ruptured food items, etc. do not directly hit the piezoelectric element sensor 1.

FIG. 3 is a block diagram depicting the controller 7 of FIG. 1 in detail. The output of the piezoelectric element sensor 1 is input to a controller 7, which controls the operation of various devices such as a radio wave emitting section 8 and a cooling fan 9. In the controller 7, a filter 16 selects a pass frequency band, an amplifier 17 amplifies the output to a level that is easy to control, a comparator 18 compares it with a set value, and a microcomputer 19 generates a control signal. For example, before boiling, the output is lower than the set value of the comparator 18, so the input to the microcomputer 19 remains unchanged and various devices continue to operate.
After boiling, the output becomes higher than the set value of the rampator 18, the input to the microcomputer 19 is reversed, and a control signal is issued to stop the operation of various devices.

With the configuration described above, it is possible to avoid direct impact of oil, water vapor, food explosions, etc. on the surface of the piezoelectric element sensor, and it is possible to always provide a stable output and obtain a constant cooking finish state.

FIG. 4 shows another embodiment. The difference from the embodiment shown in FIG. 1 is that steam and cooling air are mixed.

A part of the cooling air 21 is sent onto the top plate 3 by the duct 20,
After mixing with a portion 5 of boiling steam, it passes through a slit 6 and reaches the piezoelectric sensor 1 .

According to this configuration, a temperature rise in the piezoelectric element sensor can be suppressed, and unstable factors such as changes in output due to temperature characteristics can be eliminated, so that more stable output can be obtained.

Effects of the Invention As described above, according to the high frequency heating device with a piezoelectric element sensor of the present invention, the following effects can be obtained.

(1) Since the structure has a slit between the piezoelectric element sensor and the steam hole, oil, water vapor, and some explosives of food do not directly hit the piezoelectric element sensor, preventing false detection and premature disconnection. The boiling state of food can be accurately detected with a simple configuration.

(2) Since the piezoelectric element sensor is hard to get dirty and has a low possibility of corrosion, it has excellent long-term reliability.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a high-frequency heating device with a piezoelectric element sensor according to an embodiment of the present invention, FIGS. Figure 4 is a block diagram showing a controller, Figure 4 is a configuration diagram showing another embodiment of the present invention, Figure 5 is a configuration diagram of a conventional high frequency heating device with a humidity sensor, and Figure 6 is a configuration diagram of a conventional piezoelectric element sensor. FIG. 2 is a configuration diagram of a high-frequency heating device with a 1...Piezoelectric element sensor, 2...Heating chamber, 3...Top plate, 4...Steam hole, 6...
... Pickpocket 7), 7 ... Controller, 8 ...
...Radio wave emitting section, 9...Cooling fan. Name of agent: Patent attorney Shigetaka Awano Haka 1 person/・・−λ
Uden Riko Senp 2- Voice T! Nezumi 3... - Tenban 4 - Steam hole + - 1 - Slit γ = - Betsuhen ξ drinking a - - 5 1 ↑ 1 ↑6 1 Figure 3 Figure 4 Atsushi 5 Figure 2 and Figure 6

Claims (1)

[Claims] A heating chamber that stores a food to be cooked; a radio wave emitting section that radiates electromagnetic waves to the food to cook; a piezoelectric element sensor that detects a boiling state of the food; and a steam hole provided in the heating chamber. and a high frequency heating device with a piezoelectric element sensor, which has a slit near the steam hole and a piezoelectric element sensor installed after the slit.