JPH02157523A - Utensil of cooking by heating - Google Patents

Abstract

PURPOSE:To prevent the rise of temperature of a Piezo-electric element which can be installed at a position where the ambient temperature is low and make it possible to provide stable detection of boiling by leading the steam coming out of the steam hole of a heating chamber to a Piezo-electric element sensor by means of a wind channel formed by a pipe, etc. CONSTITUTION:A Piezo-electric element sensor 1 is installed in the lower section of a heating chamber 2, etc. in a high frequency heating device where cold wind passes and the temperature is relatively low. Part 3 of the boiling steam is blocked by a guide 4 and led to the Piezo-electric element sensor 1 through a pipe 5. The output of the Piezo-electric element sensor 1 enters a controller 6, and the electric power sources of an electric wave radiation section 7 and cooling fan 8 are turned ON and OFF by the signal of the controller 6. An object 9 to be cooked is placed in the heating chamber 2, and part 10 of the cooling air from the electric wave radiation section 7 is led into the heating chamber 2 by the cooling fan 8. The part 10 of the cooling air and the air 11 that contains steam and oil developed from the object to be cooked becomes mixture steam 12 and passes through an exhaust port 13, and part 3 of the mixture steam is sent to the guide 4, and most part 14 of the mixture steam is discharged from the louver 16 of a body cover 15 to the outside of the room.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cooking device that uses a piezoelectric sensor to detect and control 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 temperature 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.
Change the resistance value of 6 by changing the voltage of reference voltage 'rA27 from resistance 2.
The equipment is controlled by detecting the voltage by dividing the voltage with 8.

(For example, Japanese Unexamined Patent Publication No. 53-77365) Furthermore, as shown in FIG. 6, there is a method using a piezoelectric element instead of the humidity sensor. Heat is exchanged between the piezoelectric element sensor 1 and the boiling steam, and the thermal change generates a polarization current, which is detected to control the equipment. (For example, Japanese Unexamined Patent Application Publication No. 62-37624) Problems to be Solved by the Invention However, when a humidity sensor is used as described above, gas, oil, etc. in food can be detected during cooking. Since the humidity sensor gets stuck on the humidity sensor and its detection sensitivity decreases, the moisture sensor has to evaporate it with a refresh heat treatment heater every time it is cooked, which results in extra power and cost. I had an issue.

There is also a method of using a piezoelectric element instead of a humidity sensor, but since the conventional structure was to attach a piezoelectric element sensor to the exhaust part or steam hole, it is difficult to receive boiling steam directly, and the surrounding sheet metal such as the oven or body Due to the increase in temperature,
The temperature of the piezoelectric sensor also rises to a comparable high temperature. Here, since the piezoelectric element sensor generates an output according to the temperature difference ΔT between the boiling steam and the piezoelectric element sensor itself, there is a problem that ΔT becomes smaller due to the temperature increase of the piezoelectric element sensor, and the output decreases. Ta. This is because the equipment is controlled according to the output of the piezoelectric element sensor, so as the temperature of the piezoelectric element sensor rises as you cook (repeatedly), the output decreases even for the same food, and the detection time increases. In other words, there will be variations in the finished state of cooking, so it is necessary to use a temperature compensation element,
The problem was that it required some ingenuity in terms of software.

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-mentioned problems, the heating cooking device of the present invention includes a heating chamber in which a to-be-cooked object is stored, a heat source for heating the to-be-cooked object, and a heat source for heating the to-be-cooked object. The heating chamber has a steam hole, and the steam coming out of the steam hole is guided to the piezoelectric sensor through an air path such as a pipe.

Function As described above, the present invention has a structure in which boiling steam is guided to the piezoelectric element sensor through an air path such as a pipe, so there is an increased degree of freedom in the mounting position of the piezoelectric element sensor, and it is possible to mount it in a position where the ambient temperature is low. This makes it possible to prevent the temperature of the piezoelectric sensor from rising, and has the effect of stably detecting boiling with a simple configuration.

Example Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows a high V'I wave heating device showing one embodiment of the present invention. (a) shows a side view, and (b) shows a sectional view of the front view.

The piezoelectric element sensor 1 is installed in a low-temperature place where cold air passes through the high-frequency heating device (in this case, the lower part of the heating chamber 2).
will be installed on the A portion 3 of the boiling steam is received by a guide 4 and guided through a pipe 5 to a piezoelectric sensor l. The output of the piezoelectric sensor 1 enters the controller 6;
The radio wave radiator 7 and the cooling fan 8 are powered on and off by this signal.

A food to be cooked 9 is placed in the heating chamber 2 , and a portion 10 of the cooling air from the radio wave emitting section 7 is guided into the heating chamber 2 by a cooling fan 8 . Part of the cooling air 11 containing O and Ml, 1ii water vapor and oil generated from physical objects is mixed steam! 2, a part 3 of the mixed steam is sent to the guide 4 through the exhaust port 13, and a major part 14 of the mixed steam is sent to the body cover 15.
is discharged from the louver 16 to the outside of the refrigerator. In this case, a part of the exhaust port 13 is used as a steam hole for conveying steam to the piezoelectric sensor 1.

FIG. 2 is a configuration diagram of the piezoelectric element sensor.

(a) is a diagram seen from above, and (b) is a diagram of a cross section of AA' cotton seen from the side. A pair of vapor-deposited electrodes 18 are applied to a lead titanate-based piezoelectric element 17, and one end of the electrodes 18 is electrically contacted and bonded onto a metal plate 20 with an adhesive 19. A board 21 for taking out signals is led out from the electric wire i1B. Note that each lead wire is electrically insulated. In order to prevent the influence of environmental humidity, the resin 22 integrally seals the piezoelectric element 17, the electrode 18, the metal surface 19, the lead-out portion of the lead 21, etc. with a non-moisture permeable molding material.

These constitute the piezoelectric element sensor 1.

FIG. 3 is a frequency characteristic diagram of the piezoelectric element sensor output.

In contrast to the output A before boiling, the output after boiling is obtained, and boiling can be detected based on the difference between A and B. However, if the temperature of the piezoelectric element sensor rises due to repeated cooking with the conventional mounting configuration, only the output signal shown in FIG. 3 will be output even with the same amount of boiling steam. In other words, the output is rapidly attenuated.For this reason, with conventional mounting configurations, problems arise such as detection time being delayed or not being detected at all even if the food to be cooked is already boiling. On the other hand, with the configuration of the present invention, the temperature of the piezoelectric element sensor does not rise even when cooking is repeated, and if the food is of the same quantity and quality, the output shown in Fig. 3 is always obtained, and the detection time is It is possible to provide a constant and stable cooking finish state.

FIG. 4 is a block diagram depicting the control portion of FIG. 1 in detail. The output of the piezoelectric sensor 1 is input to a controller 6, which controls the operation of various devices such as a radio wave emitting section 7 and a cooling fan 8. In the controller 6, a filter 23 selects a pass frequency band, an amplifier 24 increases the output to a level that is easy to control, and inputs A/D to a microcomputer 25.
This means that the i-device control signal is issued in response to the A/D human input signal.

Effects of the Invention As described above, the high frequency heating device of the present invention provides the following effects.

(1) The structure is such that the boiling steam coming out of the steam hole is guided to the piezoelectric element sensor using an air path such as a pipe, so the piezoelectric element sensor has a large degree of freedom in terms of location and can be installed in a place with good cooling conditions. , it is possible to maintain the temperature at a low temperature, stable boiling detection can be realized, and a constant cooking finish state can be provided.

(2) Since the piezoelectric element sensor can be kept in a low temperature environment, the dependence on heat resistance increases.

(3) It becomes possible to lower the heat resistance evaluation of each of the components of the piezoelectric element sensor, such as the piezoelectric element, metal, adhesive, resin, etc., increasing the degree of freedom in material selection.

(4) Temperature correction is unnecessary, and no temperature correction element or software improvements are required, resulting in cost reduction.

[Brief explanation of the drawing]

Figures 1a and 1b are side and front views showing a high-frequency heating device according to an embodiment of the present invention, Figure 2ab is a plan view and side sectional view of a piezoelectric element sensor, and Figure 3 is a diagram of the piezoelectric element sensor output. Is the frequency characteristic diagram, Figure 4, correct? FIG. 5 is a block diagram showing a conventional high-frequency heating device with a humidity sensor, and FIG. 6 is a block diagram of a conventional high-frequency heating device with a piezoelectric element sensor. 1...Piezoelectric element sensor, 2...Heat quality, 4...Guide, 5.I...Vibe, 6.
...Controller, 7...Radio wave emitting section, 8...
...Cooling fan, 13...Exhaust port (steam hole). Name of agent: Patent attorney Shigetaka Awano

Claims (1)

[Claims] A heating chamber for storing an object to be cooked therein, a heat source for heating the object to be cooked, and a piezoelectric element sensor for detecting a cooking state of the object to be cooked, the heating chamber having a steam hole, A heating cooker configured to guide steam emitted from a steam hole to the piezoelectric element sensor through an air path such as a pipe.