JP2563919Y2 - Cooker - 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 cooking device for heating a food to be heated, and in particular, measures the weight of the food to be heated and controls a heating time, a heating output, a heating pattern and the like according to the weight. It relates to a cooking device.

[0002]

2. Description of the Related Art A microwave oven equipped with a weight sensor for measuring the weight of an object to be heated and controlling heating based on the measured weight has been rapidly spreading as a conventional heating cooker of this type in recent years. Recently, in addition to calculating the heating time from the weight, it has also been applied to detection of the type of heated food in combination with fuzzy control, and has become an important function for automation of cooking. However, as a weight sensor used in this type of microwave oven, Japanese Utility Model No. 1-41045 using a strain gauge is disclosed in Japanese Patent Application Laid-Open Nos. 59-12232 and 58-16 using a magnet and a Hall element.
No. 0742 is disclosed in Japanese Patent Application Laid-Open Nos. 61-1723 and 61-3833 using a leaf spring, a magnet, and a pickup coil.
No. 0 is known.

[0003]

The prior art described above is
Because the resistance change of the strain gauge is small, the signal level due to weight is small, the signal amplification must be increased, it is susceptible to noise, and the signal level changes when used for a long time There is a drawback, and there is a problem that the cost is high because high precision parts are required. There are also many components for other weight sensors,
There is a problem that a high-precision one is required, and there is a lot of manufacturing variation.

An object of the present invention is to solve the above-mentioned drawbacks, provide an economical and highly reliable weight sensor without using high-precision parts, accurately measure the weight of food,
An object of the present invention is to provide a heating cooker that enables good heating.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has an oscillator for supplying high frequency to food in a heating chamber, a mounting table for mounting food, and a mounting table for mounting the food. A circuit in which a pair of cylindrical magnets are attached to the elastic body at fixed intervals in parallel so that they have opposite polarities, and are disposed vertically between the pair of cylindrical magnets. The substrate is provided with a detector made of a gallium-arsenic-based Hall element, which is a magnetic sensitive element, so that the weight of the object to be heated is reliably measured by the fluctuation of the leaf spring, an elastic body, a pair of cylindrical magnets, The detector and the circuit board are mounted on a support plate made of a magnetic material, and the elastic body, a pair of cylindrical magnets, the detector and the circuit board are configured to be located between the heating chamber and the support plate. A diaphragm portion is provided with a convex portion integrally formed by a diaphragm, The half blanking portion is provided in the diaphragm portion of, it is prepared by attaching the elastic body on its half blanking portion.

[0006]

According to the present invention, as described above, the cylindrical magnet attached to one end of the leaf spring is caused by the variation in the elasticity of the leaf spring supporting the mounting table on which the food is placed due to the weight of the food. The Hall element is displaced irrespective of the characteristics, the magnetic flux density of the Hall element changes, and the Hall voltage of the Hall element is output according to the weight. By amplifying this Hall voltage, the weight can be measured as a voltage. In addition, the support plate made of a magnetic material reduces the influence of the lower part of the main body on the magnet, the detector, the circuit board, etc., eliminates the deformation of the support plate due to the load of food, improves the flatness of the mounting surface of the leaf spring, Reliability can be increased.

[0007]

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

FIG. 1 is a configuration diagram of a heating cooker according to an embodiment of the present invention, FIG. 2 is a detailed configuration diagram of the same weight sensor,
FIG. 3 is a right side view, FIG. 4 is a top view, FIG. 5 is a detailed top view of the detection unit, FIG. 6 is a schematic configuration diagram showing a main part of a throttle unit of the support plate, and FIG. FIG. 8 is a schematic configuration diagram showing a main part of the unit, FIG.
FIG. 9 is a characteristic diagram of the Hall voltage and the magnetic flux density of the Hall element, and FIG. 10 is a circuit diagram of the circuit board.

In these figures, 1 is a heating chamber for storing the food 2, 3 is an oscillator for supplying a high frequency for heating the food 2 at a high frequency, and an opening 5 provided on the side of the heating chamber 1 via a waveguide 4. Supply higher frequency. Reference numeral 6 denotes an oven heating heater provided on the wall surface of the heating chamber 1 and including a fan for generating hot air and a heating element. Reference numeral 7 denotes a grill heater provided with the heating element on the upper surface of the heating chamber 1 via a mesh metal plate. Reference numeral 8 denotes a door provided on the front surface of the heating chamber 1 so as to be openable and closable.

Reference numeral 9 denotes a mounting table on which food is mounted, which is detachably connected to a rotation drive shaft 21 of a weight sensor unit 20 provided at the bottom of the heating chamber 1. The rotary drive shaft 21 is rotatably driven by a motor 22 and is provided so as to be movable up and down. Reference numeral 11 denotes a choke cavity provided at the bottom of the heating chamber 1 so that high frequency does not leak through the rotary drive shaft 21. The motor 22 is fixed to the support plate 25 at four points by a support pipe 23 and screws 24.

One end of an elastic body (hereinafter referred to as a leaf spring) 26 is fixed to a support plate 25 made of a magnetic material by two screws 29a and 29b as shown in FIG. Magnets 27 and 28 are reversed in polarity and covered with a pair of plastic covers 34 and 35, and attached with screws 31a and 31b.

As shown in FIG. 6, the mounting surface of the support plate 25 on which the leaf spring 26 is mounted is formed by forming a half-opened portion 25b having a half or less of the plate thickness in a convex narrowed portion 25a integrally formed by a narrowed aperture. On the surface.

A nickel-plated round rivet 30 is caulked at substantially the center of the leaf spring 26, and the rotary drive shaft 2
1 through which the load of the food 2 is received. The other end 30a of the round rivet 30 corresponds to the support plate 25 when the leaf spring 26 is displaced by the load of the food 2, so that the leaf spring 26 is within the allowable stress of the material.

A circuit board 32 is mounted on the support plate 25 between the pair of cylindrical magnets 27 and 28 so as to be vertically oriented.
As shown in FIG. 7, on a circuit board 32, a detector (hereinafter, referred to as a Hall element) 33, which is a magnetic sensitive element, is arranged such that the center of the Hall element 33 is lower than the center of the pair of cylindrical magnets 27, 28 in the magnetic force direction. It is attached so that it becomes a position. Leaf spring 26
Is made of an aluminum alloy non-magnetic material.
As shown in the figure, the width W2 of the fixed surface is about 2
It is extensive. The pair of cylindrical magnets 27 and 28 are made of strontium ferrite and have an outer diameter of 10 mm and an inner diameter of 3 mm.
In addition to making it easy to mount with screws by making it a cylindrical shape with a length of 8 mm and a length of 8 mm, the cylindrical shape makes the distance between two magnets constant regardless of the mounting direction It improves the assemblability. The Hall element 33 is of a gallium-arsenic type and has a ferrite on the back side. As described above, the mounting plate driving motor 22 and the plate spring 2
6. A circuit board 32, a hall element 33, etc. are attached to form a unit, and a screw 12
a, 12b, 12c (not shown), 12d (not shown)
The mounting and assembling properties are improved.

FIG. 8 is a diagram for explaining the operation of a Hall element used as a semiconductor magnetoelectric conversion element, and FIG. 9 is a characteristic diagram of the Hall element. When a constant control current Ic is applied to the input terminals 15a and 15b to apply a magnetic field B, the Hall element 33 applies a Hall output voltage (VH = K · Ic) between the output terminals 16a and 16b.
B) occurs, and a Hall output voltage proportional to the magnetic flux density is obtained as shown in FIG. Therefore, a pair of cylindrical magnets 2
The displacement of 7, 28 can be detected by the Hall output voltage generated between the output terminals 16a, 16b. FIG. 10 is a circuit diagram of a circuit board. Power supply is +1 between COM and EW
A single 2V power supply is provided. The circuit power supply ES of the operational amplifier 91 and the transistor 92 is set to 1 by the constant voltage IC 93.
It is stabilized at 0V. The Hall element 33 is a constant current circuit 9 composed of an operational amplifier 91 and a transistor 92.
5 is output between 16a and 16b of the Hall element 33, is input to the operational amplifier 90 via the resistors R4 and R5, and is output from the output terminal 1 of the operational amplifier 90. It is amplified and output. A diode D1 is connected in series with a resistor R3 to a circuit 96 for obtaining a reference current of the constant current circuit 95. The current drive terminal 15a of the Hall element 33 is
A current of about 5.6 mA flows between −15b. In addition, a circuit including the resistors R9 and R10 and the semi-fixed resistor VR2 supplies a voltage to the + input terminal of the operational amplifier 90 via R6 so that the level of the output voltage can be adjusted by the semi-fixed resistor VR2. . The semi-fixed resistors VR1 and R8 are connected to the output terminal of the operational amplifier 90 to
1, the inclination of the output voltage with respect to the weight can be adjusted.

The temperature characteristics of the magnetic flux density of the cylindrical magnets 27 and 28 are about -1.8% / ° C., and the temperature characteristics of the output voltage with respect to the magnetic flux density of the Hall element 33 are about −0.03% / ° C.
The output tends to decrease as the temperature rises. However, in this embodiment, the diode 96 is connected in series with the resistor R3 in the circuit 96 for obtaining the reference current of the constant current circuit 95, and the drive current of the Hall element 33 is changed according to the temperature by utilizing the temperature characteristic of the diode D1. Has been increased or decreased. The temperature characteristic of the forward voltage of the diode D1 is about −2 mV / ° C., and the drive current Ic of the Hall element 33 is Ic = (EW1 / R2 / (R1 + R2) −VD1) / where the forward voltage of the diode D1 is VD1. R3. The Hall voltage VH of the Hall element 33 is shown in FIG.
Since VH = K ・ Ic ・ B, and Ic increases as the temperature increases, the operation is performed to increase the Hall voltage.
And the decrease in the output voltage due to the temperature characteristics of the Hall element 33 can be corrected.

In addition, since the cooker is used in a general household, a metal, that is, a magnetic material may be placed at the bottom of the product body, and the weight using the Hall element 33, the cylindrical magnets 27 and 28, etc. Sensors are more susceptible to magnetic effects. Fig. 2
In many cases, the cover 13 made of metal is attached as shown in FIG. However, in the present invention, the leaf spring 26 and the Hall element 3 are placed on the support plate 25 which is a magnetic material.
3. Since the cylindrical magnets 27 and 28, the circuit board 32 and the like are arranged, the influence of the lower portion of the support plate 25 is eliminated, the weight and output can be adjusted by the weight sensor unit 20, and the number of assembling steps can be reduced. it can.

In many cases, the mounting table 9 is made of a metallic material that is a magnetic material. The rotation of the mounting table 9 may affect the magnetic flux around the cylindrical magnets 27 and 28. In the present invention, since at least the bottom of the heating chamber 1 is made of a magnetic material, the influence inside the heating chamber 1 is small,
The influence of the mounting table 9 is eliminated.

As shown in FIG. 6, the mounting surface of the support plate 25 on which the leaf spring 26 is mounted is provided with a half-blanked portion 25b having a thickness of 1/2 or less of a convex narrowed portion 25a integrally formed by a diaphragm. Since the surface is formed, the flatness of the mounting surface of the leaf spring 26 can be improved, and the strength can also be improved.

[0020]

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

(1) A pair of cylindrical magnets and Hall elements mounted on the plate springs with opposite poles provide good linearity in weight-voltage, small variations due to assembly and component precision, and a large output voltage. Stable with little influence of noise.

(2) Since high precision components are not required,
It is cheap.

(3) Since a Hall element, a magnet, a circuit board, and the like are arranged between the support plate, which is a magnetic material, and the heating chamber, the influence of the lower portion of the support plate and the influence of the inside of the heating chamber are reduced, and the reliability is reduced. High weight sensor can be provided.

(4) The mounting surface of the leaf spring of the support plate is a surface formed by forming a half-blanked portion having a half or less of the plate thickness in a convex narrowed portion formed integrally by a diaphragm. The flatness of the mounting surface of the spring can be improved, and the strength can also be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a cooking device showing one embodiment of the present invention.

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

FIG. 3 is a right side view thereof.

FIG. 4 is a top view thereof.

FIG. 5 is a detailed top view of the detection unit.

FIG. 6 is a schematic configuration diagram showing a main part of a throttle unit of the support plate.

FIG. 7 is a schematic configuration diagram showing a main part of the weight sensor unit.

FIG. 8 is an explanatory diagram of a Hall element.

FIG. 9 is a characteristic diagram of the Hall voltage and the magnetic flux density of the Hall element.

FIG. 10 is a circuit diagram of the circuit board.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating room 2 Food 3 Oscillator 9 Mounting table 25 Support plate 25a Narrow part 25b Half blanking part 26 Elastic body (leaf spring) 27, 28 Cylindrical magnet 32 Circuit board 33 Detector (Hall element)

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-25691 (JP, A) JP-A-5-19807 (JP, A)

Claims (1)

(57) [Scope of request for utility model registration] 1. A heating chamber (1) for storing a food (2),
An oscillator (3) for supplying high frequency to the food (2) in the heating chamber (1), a mounting table (9) for mounting the food (2), and a supporting table (9) for supporting the food (2) An elastic body (leaf spring) (26) that generates a displacement corresponding to the weight, and the elastic body (2)
6), a pair of cylindrical magnets (27) and (28) are attached in parallel at regular intervals so as to have opposite polarities, and the magnet is sensed substantially at the center between the pair of cylindrical magnets (27) and (28). A detector (33), which is a Hall element that is a magnetic element, is provided. The detector (33) includes the pair of cylindrical magnets (27) and (28).
A circuit board (3
2) While being mounted on the upper surface, the elastic body (26), the pair of cylindrical magnets (27) and (28), the detector (33) and the circuit board (32) are mounted on a support plate (25) made of a magnetic material. And an elastic body (26), a pair of cylindrical magnets (2
7), (28), detector (33) and circuit board (32)
Is provided between the heating chamber (1) and the support plate (25), and a throttle portion (25a) is provided in which a part of the support plate (25) is integrally formed as a convex shape by a throttle. Department (25
A heating cooker characterized in that a half-cut portion (25b) is provided in a), and an elastic body (26) is mounted on the half-cut portion (25b).