JP2636423B2 - High frequency heating equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating device such as a microwave oven that measures the weight of food and performs automatic cooking.

2. Description of the Related Art Conventionally, in a microwave oven with a built-in weight detection device, it is necessary to satisfy at least the following two conditions.

One is to rotate a food table, which is a part of the weight detection device, in order to uniformly supply high frequency to food. The other is that there are various types of microwave ovens, which are large and small in view of the storage capacity, and the maximum weighing of the built-in weight detecting device is divided into various types according to the size.

A conventional example (JP-A-62-59382) will be described below with reference to FIG.

In this example, the mounting table is rotated by the support shaft 3 as a motor shaft, and the load is vertically transmitted to the sensor element from the vertically movable support shaft 3 that supports the mounting table.
The elastic body 12 of the sensor element is ceramic and simply deforms with a load. First electrode 15 printed on elastic body 12
Then, the weight is electrically detected by the change in the capacitance between the second electrodes 16 located immediately below the second electrode 16. In the case of this sensor element, the maximum weighing is a load applied until just before the upper and lower electrodes come into contact with each other.

Problems to be Solved by the Invention However, in this configuration, when developing various models,
In order to satisfy various specifications of the maximum weighing, items such as the shape of the elastic body 12, the elastic coefficient, the plate thickness, and the distance between the electrodes had to be designed for each model. Designing sensor elements for each model in this manner causes a reduction in development efficiency, and also hinders production of different sensor elements in terms of improving productivity. On the other hand, among various models, an attempt was made to share the sensor element of the model having the largest storage capacity and the largest maximum weighing capacity among all the models. However, with this, although the maximum weighing was satisfied, the elastic body of the sensor element was hardly deformed in a small model in which light weight load was important, and the resolution was poor and the measurement reproducibility was poor. As described above, in the conventional technique, it is necessary to design the sensor element according to the size of the maximum weighing.

The present invention has been made to solve the conventional problem, and an object of the present invention is to provide a high-frequency heating device having a built-in weight detection device capable of using the same sensor element regardless of the maximum weighing difference for each model.

Means for Solving the Problems In order to achieve the above object, a high-frequency heating apparatus according to the present invention includes a heating chamber, a high-frequency generator, a mounting table, a support shaft for supporting the mounting table, and a driving shaft for rotating the support shaft. A rotation drive unit for performing the operation, a weight detection unit for detecting the weight from the deformation of the elastic body due to the load, and a weight transmission unit for transmitting the weight positioned between the support shaft and the weight detection unit. It acts as a lever and receives the load of the food transmitted by the thrust displacement of the support shaft at the point of force and transmits the load from the point of application to the weight detection means.

Function The high-frequency heating device of the present invention heats the food inside the heating chamber with the high frequency supplied from the high-frequency generating means. The food is placed on the mounting table, and the total weight of the food is applied to a support shaft supporting the mounting table. The support shaft is rotated by the rotation driving means. The weight transmission located below the support shaft acts as a "lever". The power point of the lever is a portion that receives a load from the support shaft, and the action point is a portion that transmits the load to the weight detecting means. The weight detecting means detects the weight from the amount of deformation of the elastic body deformed by the load.

With this configuration, the load applied to the support shaft from the mounting table is enlarged or reduced by a predetermined load transmission ratio and transmitted to the weight detecting unit. Therefore, using the same weight detection means, it is possible to develop models of high-frequency heating devices having different maximum weighing and resolution.

Embodiment Hereinafter, a high-frequency heating device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an example in which the weight detecting device is built in a microwave oven. The magnetron 5 attached to the wall of the oven 2 sends out high frequency waves into the oven storage. The mounting table 1 is located inside the oven 2. The food to be detected is placed on the mounting table 1, and the weight of the detected object and the mounting table 1 is transmitted downward by the support shaft 3. The support shaft 3 is a shaft of a motor 4 and is freely movable in a thrust direction, and is rotated in a radial direction by a rotation driving means inside the motor 4. The motor 4 is fixed to the oven 2. The mounting table 1 rotates together with the rotation of the support shaft 3, and serves the purpose of making the distribution of high frequency to the food uniform.

At the lower end of the support shaft 3, a contact restricting portion 6 made of synthetic resin is attached. The load applied to the support shaft 3 is transmitted to the weight transmission unit 7 via the contact restriction unit 6. The weight transmitting unit 7 is a “lever” that can move about the fulcrum 8. The force point 13 is a contact portion between the contact restricting portion 6 and the weight transmitting portion 7,
Is a contact point between a spring 10 attached to the weight transmitting unit 7 and a sensor pressing unit 11 for pressing the sensor element. The load applied from the power point 13 is enlarged or reduced according to the load transmission ratio of the lever, and is transmitted to the application point 14. In this case, the distance from the fulcrum 8 to the power point 13 is equal to the distance from the fulcrum 8 to the point of application 14, the load transmission ratio is 1: 1 and the load at the point of power 13 is transmitted from the point of application 14 to the sensor element as it is. .

The sensor element has a configuration in which one elastic body 12 is attached with a small gap therebetween, and electrodes are formed on the surfaces of the elastic body 12 facing each other. When the weight is transmitted from the sensor pressurizing unit 11 and the upper elastic body is deformed, the distance between the electrodes is reduced, and the capacitance between the electrodes is changed. This is detected and converted into a weight to obtain a weight value. The maximum weight of the sensor element is the weight immediately before the two electrodes come into contact.

Spring 10 protects the sensor element from excessive loads. The spring 10 is deformed in accordance with the applied load and a predetermined spring coefficient, and the weight transmitting portion 7 also moves about the fulcrum 8 at the same time. When a load that greatly exceeds the maximum weighing is transmitted, the weight transmitting unit 7
A part 9 of the structure serves as a stopper, and a load is not applied to the sensor element any more.

In general, it is desired that the support shaft 3 is made of a ceramic material such as alumina in order to prevent the high frequency from leaking to the outside of the vessel. However, since the ceramic is formed by firing, it is easily deformed in the firing process, has high hardness, and it is difficult to process the end of the shaft, and the lower end of the support shaft 3 has an irregular shape. Therefore, if the tip of the support shaft 3 directly contacts the weight transmitting unit 7 without passing through the contact restricting unit 6, the contact point moves with the rotation, and the distance between the contact point as a force point and the fulcrum 8 fluctuates. I do. As a result, the load transmission ratio fluctuates and a detection error occurs. The contact restricting unit 6 prevents such a movement of the power point 13. In this embodiment, the contact restricting section 6
Was mounted in a hemispherical shape so that the power point 13 was located on the rotation axis of the support shaft 3, and the power point was not moved with the rotation of the support shaft 3. Since the contact restricting portion is made of synthetic resin, such molding is easy.

FIG. 2 shows that the load transmission ratio is changed by shifting the position where the portion A surrounded by the dotted line in the drawing is attached to the main body.

FIG. 2 (a) shows that the distance from the power point 13 to the fulcrum 8 is smaller than the distance from the action point 14 to the fulcrum 8, a load smaller than the actual weight is transmitted to the sensor element, and the maximum weighing is larger than that of the configuration of FIG. That is, the configuration is for a model having a large storage capacity.

FIG. 2 (b) shows that the distance from the power point 13 to the fulcrum 8 is larger than the distance from the point of application 14 to the fulcrum 8, a load larger than the actual load is transmitted to the sensor element, and the maximum weighing is smaller than in the configuration of FIG. In other words, the configuration is for a model with a small storage capacity. In this example, since a load larger than the actual weight is transmitted to the sensor element, even if the food is small, the elastic body 12 is dynamically deformed to obtain a sufficient resolution.

The weight is calculated in advance according to a calculation formula set in the microcomputer of the main body, and a correct weight is calculated by setting different calculation formulas for each of FIGS. 1, 2 -a and 2 -b.

Even if the same sensor element and the same mechanical component are used as in these embodiments, the model can be developed by satisfying the specifications of the maximum weighing size and resolution only by changing the load transmission ratio of the lever by changing the mounting position. You.

In the above embodiment, the capacitance type sensor element 10
The same effect can be obtained by bonding a strain cage, which is a general-purpose component, to the spring 10. As described above, a sensor element of a type that detects weight by elastic deformation can be easily used.

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

By acting as a weight transmission unit "lever", the weight of the object placed on the mounting table is enlarged or reduced and transmitted to the weight detection means, so that a high-frequency heating device with different maximum weighing or sensitivity or resolution When deploying models to
If the lever transmission ratio is redesigned, the same weight detecting means can be used without changing the characteristics of the weight detecting means.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a high-frequency heating device according to one embodiment of the present invention, FIGS. 2 (a) and 2 (b) are configuration diagrams of a high-frequency heating device according to another embodiment of the present invention, and FIG. FIG. 3 is a configuration diagram of a weight detection device mounted on a heating device. 1 ... Placement table, 3 ... Support shaft, 4 ... Motor, 5 ...
Magnetron, 6 contact control part, 7 weight transmission part,
10 ... spring, 12 ... elastic body.

Claims (1)

(57) [Claims] A heating chamber for accommodating food; a high-frequency generator for supplying high frequency to the heating chamber; a mounting table inside the heating chamber for mounting the food; and a support shaft for supporting the mounting table. A rotation driving unit for rotationally driving the support shaft, a weight detection unit for detecting the weight of the food from deformation of the elastic body due to a load, and a weight positioned between the support shaft and the weight detection unit. A weight transmission unit for transmitting the weight, the weight transmission unit acting as a "lever", receiving the load of the food transmitted by the thrust shift of the support shaft at a power point, and transmitting the load from the point of action to the weight detection means. A high-frequency heating device configured to