JP2561523Y2 - High frequency heating equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus provided with a weight detection sensor for measuring the weight of an object to be heated.

[0002]

2. Description of the Related Art Conventionally, a large number of heating and cooking devices for heating food stored in a heating chamber and automatically cooking the food have been put into practical use. Oven cooking and grilled cooking of grilled fish etc. are now possible and convenient. Further, the weight of the food is automatically measured, the heating time and the heating output are determined based on the weight, and the food is automatically heated to improve the usability. Japanese Patent Application Laid-Open No. Sho 59-1 uses a magnet and a Hall element as a weight sensor for food, for example, which is related to this type of cooking device.
No. 2232 and Japanese Patent Application Laid-Open No. 58-160742 are known.

[0003]

In the above-mentioned prior art using a magnet and a Hall element, the influence of variations in the assembly and processing of the weight detection circuit of the object to be heated is required in order to ensure accurate weight detection. It is necessary to make the voltage generated in the Hall element at the time of weight detection proportional to the detected weight, so that the electronic components that make up the weight detection circuit and leaf springs that flex according to the weight are also high. Care must be taken to use precision ones and the like, and there has been a problem that the manufacturing cost naturally increases.

The present invention solves the above-mentioned conventional problems, and in particular, it is necessary to use a high-precision electronic component constituting a central weight detection circuit and a leaf spring that bends according to the weight, etc. Another object of the present invention is to provide a high-frequency heating apparatus having a weight detection sensor that is highly economical and has improved weight detection accuracy that is less affected by variations during assembly and processing.

[0005]

In order to achieve the above-mentioned object, a high-frequency heating device according to the present invention comprises an elastic member which displaces a magnetoelectric changing element in accordance with the weight of an object to be heated placed on a mounting table. Is provided between a pair of magnets which are fixed to a part of the magnet with an appropriate interval, and is heated by a signal from a weight detection circuit which detects the weight of the object to be heated based on the displacement of the magnetoelectric conversion element and the pair of magnets. The reference voltage value setting means controls the operation of the plurality of heating energy generating means for heating the object, and sets the voltage output from the magnetoelectric conversion element to a predetermined reference voltage in advance when detecting the weight of the object to be heated. This is provided in the detection circuit.

[0006]

In the present invention, the weight detection circuit is provided with reference voltage value setting means for previously setting the voltage output from the magnetoelectric conversion element to a constant reference voltage, so that the voltage output from the magnetoelectric conversion element can be changed to a desired value. It is possible to easily set (adjust) to a certain reference voltage, and use high-precision ones for the electronic parts used in the weight detection circuit and the elastic members that bend according to the weight of the object to be heated. No longer needed
Does not require assembly and processing accuracy of advanced weight detection circuit.

Further, in order to preliminarily adjust the voltage output from the magnetoelectric transducer to a constant reference voltage, the output voltage can be obtained as a voltage almost proportional to the weight of the object to be heated. Of the weight detection circuit is not easily affected by variations during assembly and processing of the weight detection circuit.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 is a schematic side sectional view of a high-frequency heating device main body according to the present invention, FIG. 2 is a plan view of a main part of a weight sensor of the high-frequency heating device, and FIG. FIG. 4 is a side view of a main part, and FIG. 4 shows a weight detection circuit of the high frequency heating device.

In FIGS. 1, 2 and 3, reference numeral 1 denotes a heating chamber for accommodating an object to be heated, which is formed in a main body H of a high-frequency heating apparatus and has a mesh metal plate 11 arranged on a ceiling. Reference numeral 2 denotes a high-frequency oscillating unit for supplying microwaves into the heating chamber 1, and 3 denotes an oven heater unit provided outside the heating chamber 1 and provided with a fan and a heating element for blowing hot air into the heating chamber 1. Is a grill heater provided above the mesh metal plate 11 for heating the inside of the heating chamber 1. The high-frequency oscillator 2, the oven heater 3 and the grill heater 4 constitute a plurality of heating energy generating means. ing. Reference numeral 5 denotes a mounting table provided in the heating chamber 1 for mounting an object to be heated, and 6 denotes a mounting table 5 provided on the outer bottom of the heating chamber 1.
Is provided below the driving unit 6, and controls the weight of the object to be heated based on the movement of the rotating shaft 61 which moves up and down in accordance with the weight of the object to be heated on the mounting table 5. It is a weight detection sensor to detect. Reference numeral 71 denotes a support attached to the outer bottom of the heating chamber 1, and the drive unit 6 and an elastic member 72 located below the drive unit 6 are attached to the support 71. The elastic member 72 is made of a flat non-magnetic material having a bifurcated tip made of an aluminum alloy or the like.
A rivet 75 made of stainless steel or the like is fixed to a portion that comes into contact with the rivet when it moves downward. Two cylindrical magnets 73 made of strontium ferrite or a rare earth magnet are provided at the tip of the bifurcated portion in parallel with non-magnetic screws 76 so as to have opposite polarities. Reference numeral 74 denotes a magnetoelectric conversion element (hereinafter, a Hall element) including a gallium / arsenic-based crystal on one side and ferrite on the other side, and is located at a substantially central portion between the two magnets 73 in an appropriate portion of a substrate 77 described later. The small voltage generated in the Hall element 74 is detected with high sensitivity according to the minute movement of the two magnets 73, and the weight of the object to be heated on the mounting table 5 is detected (measured) based on the detection result. Is what you do. Reference numeral 77 denotes a substrate on which a weight detection circuit C for measuring the weight of the object to be heated based on the voltage detected by the Hall element 74 is attached, and the plurality of energy generating means 2 correspond to the detected weight of the object to be heated. A control circuit (not shown) for controlling the energization of 3 and 4 is provided, and cooking is performed by the control circuit and the weight detection circuit C and the like. 78
Is a forcible stop for restricting the maximum displacement of the elastic member 72, which is formed on the support body 71 located below the rivet 75, and which is elastic when an excessive load is applied to the rotation shaft 61 of the mounting table 5. The elastic member 72 does not bend more than necessary so as not to exceed the maximum stress of the member 72.

In the weight detection circuit C shown in FIG. 4, reference numeral 8 denotes a constant current circuit having an operational amplifier 81, a transistor Q1, and the like. Reference numeral 9 denotes a magnetic field around the current when a current is supplied from the constant current circuit 8 to the terminals 2 and 4. (Not shown), a magneto-electric conversion circuit composed of a Hall element 74 for generating a voltage at terminals 1 and 3 by a synergistic action with an amplification element 82 for amplifying an output voltage from the magneto-electric conversion circuit 9 and an output from the amplification element 82 A variable resistor VR for varying the input voltage to the + terminal 3 of the amplifying element 82 in order to set the voltage in advance to a certain reference voltage value
2 is an amplifying circuit having reference voltage value setting means K and the like. Each of these circuits 8, 9 and 10 etc.
And constitutes a weight detection circuit C. WS is a terminal for inputting an output voltage from the amplifier circuit 10,
7 is a part for inputting an output voltage from the amplifier circuit 10 to a control circuit or the like. Further, EW and COM are terminals provided on the substrate 77, and are portions where a DC voltage is applied to the weight detecting circuit C via the voltage stabilizing circuit 83.

Next, the operation of this embodiment will be described.

Since the ferrite attached to the Hall element 74 is located between the magnets 73, 73 as described above, the state of the magnetic field formed in the minute gap between the magnets 73, 73 and the ferrite is N · The magnetic pole density between the two magnets 73 and 73 becomes a polar arrangement such as SNS
The number increases toward the end of 73.

Therefore, when the object to be heated is not mounted on the mounting table 5, the two magnets 73, 73 fixed to the elastic member 72 are provided.
The Hall element 74 located between them is located at the center between the two magnets 73 having the lowest magnetic flux density.

When detecting the weight of the object to be heated, the DC voltage applied to the terminals EW and COM on the substrate 77 is applied to the voltage stabilizing circuit 8.
3 is applied to the weight detection circuit C via the constant current circuit 8 and a constant current is applied to the Hall element 74 of the magnetoelectric conversion circuit 9.
To terminals 2 and 4.

Next, when the object to be heated is mounted on the mounting table 5,
Hall element 74 located at the center of both magnets 73, 73
Is an elastic member that attaches the two magnets 73, 73 so that the magnets 73, 73 are positioned from the central part where the magnetic flux density of the magnetic field between the two magnets 73, 73 is low to the end part where the magnetic flux density of the magnetic field between the two magnets 73, 73 is high. The two magnets 73, 7 are bent while the 72 is not vibrating.
3 moves 2-3 mm.

Accordingly, when detecting the weight of the object to be heated, the Hall element 74 is located in a magnetic field having a magnetic flux density proportional to the weight, and the small voltage generated in the Hall element 74 in response to the minute movement of the two magnets 73 is sensitive. A voltage proportional to the bending of the elastic member 72 is output from the terminals 1 and 3 of the Hall element 74 where a constant current flows to the terminals 2 and 4 while being well detected, and this voltage is applied to the terminals 2 and 3 of the amplifying element 82. input.

Here, the input voltage to the + terminal 3 of the amplifying element 82 is set to a reference voltage value so that the output voltage from the terminal 1 of the amplifying element 82 becomes 5 mv when a weight of 5 kg is placed on the mounting table 5. Since the voltage is adjusted in advance by the variable resistor VR2 of the setting means K, the output voltage from the terminal 1 of the amplifying element 82 becomes a voltage that changes linearly in proportion to the weight of the object to be heated, Input to terminal WS.

The voltage input to the terminal WS is input to the control circuit, and a plurality of energy generating means 2, 3 and 4 for heating the object to be heated according to the detected weight of the object to be heated.
Control the operation of.

[0020]

The present invention is configured as described above, so that the following effects can be obtained.

Since the weight detection circuit is provided with reference voltage value setting means for previously setting the voltage output from the magnetoelectric conversion element to a constant reference voltage, the voltage output from the magnetoelectric conversion element when the weight of the object to be heated is detected. Can be easily set (adjusted) to a desired constant reference voltage, so it is necessary to use high-precision electronic components for the weight detection circuit and elastic members that bend according to weight. This eliminates the need for much accuracy when assembling and processing the weight detection circuit. This improves the assemblability of the weight detection circuit, reduces the manufacturing cost, and further increases the positive terminal of the amplification element when detecting the weight of the object to be heated. Since the input voltage to the amplifier is adjusted in advance by the reference voltage value setting means, the output voltage from the amplifying element can be obtained as a voltage almost linearly proportional to the weight of the object to be heated. Assembly of the weight detection circuit in detecting the weight accuracy of the thermal material not easily affected by variations in processing, to obtain a weight detection sensor with improved detection accuracy.

[0022] Thereby, the plurality of energy generating means can be properly controlled, and the object to be heated can be favorably cooked.

[Brief description of the drawings]

FIG. 1 is a schematic side sectional view of a main body of one embodiment of the present invention.

FIG. 2 is a detailed configuration diagram of the weight detection sensor.

FIG. 3 is a sectional view of a main part of a weight detection portion of the weight detection sensor.

FIG. 4 is a circuit diagram of the weight detection circuit.

[Explanation of symbols]

 2, 3, 4 Energy generating means 5 Mounting table 72 Elastic member 73, 73 Magnet 74 Magnetoelectric conversion element C Weight detection circuit K Reference voltage value setting means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Katsuhiro Yamazaki, Investigator Yoshifumi Muramoto, Examiner, Hitachi Home Tech Co., Ltd. 3-1, Shinjuyoji 2 Kashiwa-shi, Chiba

Claims (1)

(57) [Scope of request for utility model registration] 1. A mounting table (5) on which an object to be heated is mounted, an elastic member (72) displaced in accordance with the weight of the object to be heated mounted on the mounting table (5), and an elastic member (72) and a pair of magnets (73) and (73) fixed at appropriate intervals to this magnet (7).
3) A magneto-electric conversion element (74) provided between (73) and driven by a constant current, and is heated based on the displacement of the magneto-electric conversion element (74) and the pair of magnets (73) and (73). Operation of a weight detection circuit (C) for detecting the weight of an object, and a plurality of heating energy generating means (2), (3) and (4) for heating an object to be heated by a signal from the weight detection circuit (C) In the high-frequency heating device, the reference voltage value setting means (K) for previously setting a voltage output from the magnetoelectric conversion element (74) to a constant reference voltage when detecting the weight of the object to be heated is provided by the weight detection circuit. A high-frequency heating device provided in (C).