JP3690568B2 - Weight detector for cooking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a weight detection device for a cooking device that detects the weight of a cooking object placed on a turntable in a cooking device such as a microwave oven, and more particularly, to a cooking object placed on a turntable. The present invention relates to a weight detection apparatus for a heating cooker that detects the weight of the cooking device as a change in capacitance.
[0002]
[Prior art]
In a recent cooking device such as a microwave oven, a weight detection device for detecting the weight of a cooking object placed on the turntable is provided, and the cooking performed on the turntable prior to cooking. There has been provided a device that automatically detects the weight of an object by a weight detection device and cooks the food according to the detected weight. A weight detection device (a weight detection device for a cooking device) used for a microwave oven or the like will be described.
[0003]
The longitudinal cross-sectional front view of the part concerning the weight detection apparatus for heating cookers of a heating cooker is shown in FIG. In the figure, 10 is a heating chamber, 11 is a turntable disposed in the heating chamber 10, 12 is a support shaft of the turntable, and 13 is a turntable plate provided at the upper end of the support shaft 12. A boss portion 13a of the turntable plate 13 is fitted into the support shaft 12 of the turntable with a predetermined size, and a flange portion 13b is configured to place the turntable 11 thereon.
[0004]
Below the heating chamber 10, a motor mounting bracket 14 is fixed to the heating chamber 10 by spot welding, for example, and a unit in which the turntable driving device 15 and the weight detection device 16 are assembled into the motor mounting bracket 14. 17 is attached by screws 18. The turntable driving device 15 is an assembly in which a turntable motor 19, a reduction mechanism (not shown), and a support shaft 12 are attached to a metal case 20.
[0005]
This will be further described with reference to FIG. 4 which is an enlarged view of a portion surrounded by a circle C in FIG. A resin cap 12b is integrally formed on the support shaft 12 at the lower end of the ceramic shaft 12a. Reference numeral 12d denotes a protective rib provided at the lower end of a reinforcing rib 12e (not shown) formed integrally with the cap 12b. When the support shaft 12 is overloaded, the raised portion 20a of the metal case 20 is provided. The weight detecting device 16 is protected by abutting against.
[0006]
The weight detection device 16 is composed of a fixed electrode plate 21 and a movable electrode plate 23 which are provided with a slight gap between them to form an air capacitor, and are fixed to the lower side of the support shaft 12 with screws. The fixed electrode plate 21 is a conductor-clad laminate generally referred to as a printed circuit board in which an electrical conductor such as copper foil is attached to the surface of a laminate such as phenol or epoxy resin. A conductor pattern is formed.
[0007]
As shown in FIG. 5, the movable electrode plate 23 is a rectangular plate spring in which a conductive metal plate is formed in a gimbal spring shape as shown in FIG. 5, and when a load is applied to the center of the center plane portion 23a, While maintaining a flat surface, it moves up and down to act as a movable electrode, and the rotational torque of the support shaft 12 is reduced.
[0008]
In the conventional heating cooker weight detection device, a conical or spherical protrusion 12c for making point contact with the movable electrode plate 23 of the weight detection device 16 is provided at the rotation center of the cap 12b.
[0009]
With the above configuration, when the object to be cooked is placed on the turntable 11, the support shaft 12 is displaced in the thrust direction by an amount corresponding to the weight of the object to be cooked. By this displacement, the protrusion 12C of the support shaft 12 is displaced. Thus, a load is applied to the central flat portion 23a of the movable electrode plate 23, and the movable electrode plate 23 is displaced downward by an amount corresponding to the weight of the object to be cooked. Due to the displacement of the movable electrode plate 23, the dimension of the gap between the fixed electrode plate 21 and the movable electrode plate 23 changes, and the capacitance of the air capacitor formed by the fixed electrode plate 21 and the movable electrode plate 23 is changed to the movable electrode plate. It changes by a value corresponding to the displacement amount of 23. The amount of change in capacitance is converted into a weight by an external weight detection circuit (not shown), and cooking is controlled based on the conversion result.
[0010]
[Problems to be solved by the invention]
However, in the above-described conventional weight detecting device for a heating cooker, when the mounting position of the movable electrode plate 23 with respect to the support shaft 12 varies, a load is applied to the central flat portion 23a of the movable electrode plate 23 by the protrusion 12c of the support shaft 12. As a result, the displacement of the movable electrode plate 23 varies even with the same load. That is, in the conventional cooking device weight detection device, there is a problem that the detected weight for the same cooking object varies due to variations in assembly.
[0011]
Then, an object of this invention is to provide the weight detection apparatus for heating cookers which eliminated the dispersion | variation in the detected weight by the dispersion | variation in an assembly.
[0012]
[Means for Solving the Problems]
To achieve the above object, in the heating cooker weight detecting device of the present application, a table cooking object is placed, a support shaft for supporting the table, movable relative to fixed electrode plate and the fixed electrode plate a Ru consists the movable electrode plate, and a heavy amount detector, when the cooking object is put on the table, to press the movable electrode plate wherein the support shaft is displaced in the thrust direction, is pressed and the weight of the cooking object capacitance pore size is changed is placed on the table by Rukoto to change in between said the movable electrode plate is displaced the fixed electrode plate and the movable electrode plate The weight detection device for a cooking device to be detected is configured to have a protrusion formed by drawing and receiving a displacement in the thrust direction of the support shaft as a point load .
[0013]
With the above configuration, even when the mounting position of the movable electrode plate with respect to the support shaft varies, the point at which the load is applied to the movable electrode plate is constant, and the displacement amount of the movable electrode plate is constant for the same load.
[0014]
In the heating cooker weight detection device having the above-described configuration, the height of the protrusion may be substantially the same as the thickness of the movable electrode plate.
[0015]
With the above configuration, it is easy to form protrusions on the movable electrode plate, which is preferable for the rotation of the support shaft.
[0016]
Moreover, in the weight detection apparatus for heating cookers having the above-described configuration, the protrusion may be hemispherical .
[0017]
If a crack is formed at the tip of the diaphragm protrusion formed on the movable electrode plate, the rotational torque of the support shaft increases . However, since the diaphragm protrusion formed on the movable electrode plate has a hemispherical shape due to the above configuration , there is no possibility that the tip of the protrusion provided on the movable electrode plate is cracked during the drawing process.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of a main part of a weight detecting device for a cooking device according to an embodiment of the present invention. FIG. 2 is a plan view and a right side view of the movable electrode plate 22 as viewed from below. In addition, the same code | symbol is attached | subjected to the part same as a prior art, and description is abbreviate | omitted. A hemispherical diaphragm protrusion 22b is provided at the center of the central flat portion 22a of the movable electrode plate 22 so that the center thereof coincides with the center of rotation of the support shaft 12. In response to this, the bottom surface of the cap 12b of the support shaft 12 is a flat smooth surface.
[0019]
Thus, in the cooking-by-cooker weight detection apparatus of this embodiment, since the protrusion 22b for receiving the displacement of the support shaft 12 in the thrust direction as a point load is provided on the movable electrode plate 22, it is caused by the assembly work. Even if the mounting position of the movable electrode plate 22 with respect to the support shaft 12 varies, the point at which the load is applied to the movable electrode plate 22 is constant, and the amount of movement of the movable electrode plate 22 with respect to the same load is constant. Therefore, it is possible to eliminate variations in detected weight due to variations in assembly.
[0020]
In the processing of the movable electrode plate 22, by forming the mounting hole 22c and the projection 22b for mounting the movable electrode plate 22 in the same process, there is no variation in the positional relationship between the mounting hole 22c and the projection 22b. The point receiving the load of the electrode plate does not vary from part to part. Therefore, it is possible to eliminate the variation in the detected weight due to the parts.
[0021]
It should be noted that the height of the hemispherical diaphragm protrusion 22b is preferably about the thickness of the plate (about 1 mm), and is preferable for the rotation of the support shaft 12. Here, if the tip of the squeezing protrusion 22b is too sharp, there is a risk of cracks occurring during the drawing process. If cracks occur, the coefficient of friction between the support shaft 12 and the cap 12b increases, the rotational torque increases, and smoothness occurs. Hinders proper rotation. On the other hand, in the present embodiment, since the diaphragm protrusion 22b is hemispherical, there is no risk of cracking at the tip of the protrusion, the rotational torque of the support shaft 12 can be kept small, and smooth rotation is achieved. There is no hindrance.
[0022]
【The invention's effect】
As described above, according to the heating cooker weight detection device of the present application , even if the mounting position of the movable electrode plate with respect to the support shaft varies due to assembly work, the point at which the load is applied to the movable electrode plate is constant. Since the amount of movement of the movable electrode plate with respect to the same load is constant, variations in detected weight due to variations in assembly can be eliminated.
[0023]
In addition, there is no variation in the positional relationship between the mounting hole and the protrusion in the movable electrode plate, and the point of receiving the load on the movable electrode plate does not vary from component to component, so that variation in detected weight due to components can be eliminated.
[0024]
Further, since there is no possibility of cracks at the tips of the protrusions formed on the movable electrode plate during drawing, the rotational torque of the support shaft can be kept small.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a weight detector for a cooking device according to an embodiment of the present invention.
FIGS. 2A and 2B are a plan view and a right side view of a movable electrode plate viewed from below according to the present embodiment.
FIG. 3 is a longitudinal sectional front view of a portion related to a weight detection device for a cooking device of a cooking device.
FIG. 4 is a cross-sectional view of a main part of a conventional weight detector for a heating cooker.
FIGS. 5A and 5B are a plan view and a right side view of a movable electrode plate in the prior art as viewed from below. FIGS.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Heating chamber 11 Turntable 12 Support shaft 12a Ceramic shaft 12b Cap 12c Protrusion 12d Protection rib 12e Reinforcement rib 13 Turntable plate 13a Boss part 13b Flange part 14 Motor mounting bracket 15 Turntable drive device 16 Weight detection device 18 Screw 19 Turntable Motor 20 Metal case 20a Raised portion 21 Fixed electrode plate 22 Movable electrode plate 22a Center plane portion 22b Projection 22c Mounting hole 23 Movable electrode plate 23a Center plane portion

Claims (3)

A table on which an object to be cooked is placed;
A support shaft for supporting the table;
Formed Ru and a movable movable electrode plate with respect to the fixed electrode plate and the fixed electrode plate, and a heavy amount detector,
When the object to be cooked is placed on the table, the support shaft is displaced in the thrust direction to press the movable electrode plate,
The was pressed by the movable electrode plate displacement heating cooking object placed on the said table by Rukoto to change the capacitance pore size is changed between the movable electrode plate and the fixed electrode plate In the weight detection device for a heating cooker that detects the weight,
Heating cooker weight detection apparatus projections for receiving the drawing is formed by point load in the thrust direction of displacement of the support shaft, characterized in that provided on the movable electrode plate.   The weight detection apparatus for a heating cooker according to claim 1, wherein the height of the protrusion is substantially the same as the thickness of the movable electrode plate.   The weight detection apparatus for a heating cooker according to claim 1 or 2, wherein the protrusion is hemispherical.

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