JPH0333975B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a structure for mounting a weight detector in a high-frequency heater.

Conventional configurations and their problems Electronics technology has made remarkable progress in recent years, and is being applied to household appliances, contributing to a richer and more convenient lifestyle. Looking at high-frequency heaters, which have recently become more popular, they are equipped with a microcomputer as the brain, temperature sensors, humidity sensors, and infrared sensors as sensory organs, and relays and thyristors as actuators. Some devices automatically cook food by controlling output, time, and temperature once food is placed in the heating chamber and cooking is started. The principle of automatic cooking is as follows. When cooking cakes, kutskii, etc. in the oven, the controlled temperature and cooking time of the heating chamber are memorized and the cooking is performed for a certain period of time. When reheating cold rice, etc., as the heating progresses, the amount of steam generated from the food increases rapidly, causing a change in the humidity in the heating chamber. The humidity sensor detects this change and automatically cooks the food.
However, when defrosting frozen meat, some products automatically thaw by detecting the surface temperature of the meat, but since they only detect the extremely small surface temperature, the results may vary depending on the shape and mass of the meat. However, it has not yet become widely available. The currently widespread defrosting method involves inputting the weight of the food using a volume controller, etc., and defrosting the food by having a microcomputer perform optimal output control determined through experiments according to the weight of the food. With changes in eating habits, large refrigerators and freezers have become popular, and more and more households are now storing food frozen and thawing it as needed for use in cooking.The role of defrosting using high-frequency heaters is now playing an important role. It's reached. However, although the latter automatic defrosting method, which is currently widely used, provides good defrosting conditions, it has the disadvantage that the user must measure and input the weight of the food.

Purpose of the Invention The present invention has been made to eliminate the above-mentioned conventional drawbacks.The present invention has a stable mounting structure for a weight detector to achieve highly accurate weight detection performance, eliminating the need for weight measurement by the user and greatly increasing the use of the device. The purpose of the present invention is to provide a high-frequency heater with improved performance.

Structure of the Invention In order to achieve the above object, the high frequency heater of the present invention has a strong fixing plate made of a metal plate attached to the bottom of the heating chamber, and a weight detector is attached via this, so that the heating chamber It can prevent deformation and vibration of the bottom surface and enable highly accurate weight detection.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below based on the drawings.

A first diagram showing a cross-sectional view of the main parts of the high-frequency heater of the present invention.
In the figure, a fixing fitting 4 formed of a metal plate is attached to the bottom surface 3 of a heating chamber 2 in which an object to be heated 1 is housed. One end of a roberval mechanism 7 composed of an elastic body 5 and a metal block 6 is fixed to the fixture 4. A shaft 8 is fixed to the other end of the Roberval mechanism 7 and supports a mounting table 9 on which the object to be heated 1 is placed. A chiyoke 10 is formed at a portion of the bottom surface 3 of the heating chamber 2 from which the shaft 8 is pulled out. A magnet 11 is attached to one end of the Roberval mechanism 7 that is not fixed, and a winding 12 is fixed near the magnet 11. Winding 12 is connected to output control section 13 . The magnetron drive section 14 receives a signal from the output control section 13 and causes the magnetron 15 to oscillate or stop oscillation.

The operation of the above configuration will be explained below.

When the object to be heated 1 is placed on the mounting table 9, the impact causes the Roberval mechanism 7, which supports the entire mass of the object to be heated 1, to vibrate up and down at a natural frequency corresponding to the weight of the object to be heated 1. Due to this vibration, an induced voltage having the above-mentioned natural frequency is generated in the winding 12 provided opposite to the magnet 11. The output control section 13 is connected to the winding 1
The weight is determined from the frequency of the induced voltage generated in step 2, and a predetermined output control signal is generated. The magnetron drive unit 14 receives the control signal and controls the oscillation of the magnetron.

According to this embodiment, the weight of the object to be heated 1 is entirely supported by the fixture 4 via the Roberval mechanism 7, so by making the plate thickness and shape of the fixture 4 strong, The heating chamber 2 can be made of a thin plate and can be constructed at low cost.

Furthermore, by making the fixing fittings 4 strong, all the weight of the object to be heated 1 is converted into the movement of the Roberval mechanism 7, making it possible to detect the weight with high accuracy.

Furthermore, by strengthening the fixing metal fittings 4,
Since the vibrations of the Roberval mechanism 7 do not escape into the heating chamber 2, the vibrations are not easily attenuated and a stable induced voltage can be generated.

Other embodiments are shown in FIGS. 2, 3, and 4.

In FIG. 2 showing a cross section of the main part of this embodiment, a ring-shaped drawing process with a depth h is provided on the bottom surface 3 of the heating chamber 2. In FIG. 3 showing the configuration of the bottom surface 3 of the heating chamber 2, a fixing metal fitting 4 having the cross-sectional shape shown in FIG. Letting the inner diameter of the processed part be Di, there is a relationship l>Di.

With this configuration, it is possible to secure a sufficient distance between the mounting table 9 and the bottom surface 3, making it possible to lower the position of the mounting table 9, and increasing the effective height dimension of the heating chamber 2. have an effect.

Further, by providing a ring-shaped drawn portion on the bottom surface 3, the strength of the bottom surface 3 itself can be improved, and a more stable induced voltage can be generated.

FIG. 5 shows another embodiment.

FIG. 5 is a sectional view of the bottom surface 3 of the heating chamber 2.
A hole of φD is drilled in the bottom surface 3, and the hole is closed with a bottom surface B16 formed by drawing another sheet metal. Chiyoke 10
is configured on the bottom surface B16. The fixture 4 is also attached to the bottom surface B16.

With such a configuration, the bottom surface B16
If it is desired to increase the drawing depth, only the bottom surface B16 can be made of a material that is easy to draw and has a high unit price, and can be realized at low cost. Furthermore, when it is necessary to improve the strength, it is possible to make the structure inexpensive by increasing the thickness of only the bottom surface B16.

FIG. 6 shows another embodiment.

FIG. 6 is a sectional view of a main part showing this embodiment. Attach the nut 1 to the fixing part of the roberval mechanism 7 of the fixing bracket 4.
7 is attached by welding etc., and the Roberval mechanism 7
is fixed to the nut 17 with a machine screw 18.

With the above configuration, it is possible to increase the tightening torque, prevent the machine screw from loosening and rattling against overload and impact, and reduce the weight of the object to be heated 1. are all converted into movements of the Roberval mechanism 7, allowing highly accurate weight detection.

FIG. 7 shows another embodiment.

A Roberval mechanism 7 is fixed to the fixture 4, and a motor 19 is fixed to the unfixed metal block portion 6' of the Roberval mechanism 7 to rotate the apparatus stand 9 via the shaft 8. A metal plate 20 is fixed to the lower surface of the metal block 6'.
Furthermore, opposite to the metal plate 20, another metal plate 21
is fixed via an insulator 22. The metal plates 20 and 21 are connected to the output control section 13.

The operation of the above configuration will be explained.

When the object to be heated 1 is placed on the mounting table 9, the Roberval mechanism 7 that supports the entire weight of the object to be heated 1,
It elastically deforms and changes position depending on the weight. As a result, the gap dimension t between the metal plates 20 and 21 changes, and the capacitance formed by the metal plates 20 and 21 changes. The output control section 13 detects the capacitance, determines the weight of the object to be heated 1, and generates a predetermined output control signal. The magnetron drive unit 14 receives the control signal and controls the oscillation of the magnetron.

With the above configuration, when the object to be heated 1 is placed on the periphery of the mounting table 9 instead of in the center, an unbalanced load is applied to the Roberval mechanism 7, a twisting force is applied to the Roberval mechanism 7, and the object is Depending on the position where the heated object 1 is placed, the dimension t between the metal plates 20 and 21 may change, making it impossible to accurately detect the weight. However, by rotating the mounting table with the motor 19, the average dimension t is obtained, and the same accuracy as when the object to be heated is placed at the center of the mounting table 9 can be obtained.

Furthermore, since the Roberval mechanism 7 is fixed to the strong fixture 4, even if an uneven load is applied, the Roberval mechanism 7 will be deformed. The weight of the object to be heated 1 can be detected.

Furthermore, by rotating the heated object 1,
Heating unevenness caused by high frequency heating can be improved.

FIG. 8 shows another embodiment.

In FIG. 8, which is a front view of the high-frequency heater of this embodiment and shows a cross-section of the lower part of the heating chamber, the bottom surface 3 of the heating chamber 2 is provided with a ring-shaped drawn part, and the processed part has many openings. Fixing bracket 4 provided with 23
is installed. A roberval mechanism 7 including a motor 19 is attached to the fixture 4. The lower part of the Roberval mechanism 7 of the bottom plate 24 of the high frequency heater of the present invention is hollowed out and the end face is bent inward to close the gap with the fixing metal fitting 4. The hollowed out portion of the bottom plate 24 is drawn and closed by a lid 26 in which a large number of openings 25 are provided. An electric heating device 2 is installed at the bottom of the heating chamber 2.
7 is installed. Changes in the Roberval mechanism 7 due to the weight of the object to be heated 1 are detected by the detection unit 28 . The signal from the detection unit 28 is input to the output control unit 29, which determines the weight of the object to be heated 1, generates a stored control signal in advance, and drives the magnetron 15 through the drive unit 14 to oscillate the magnetron. At the same time, the power supply to the electric heating device 27 is controlled.

The above configuration has the following effects.

By providing the electric heating device 27, it is not only possible to cook sponge cakes, grilled fish, etc., which was impossible with conventional high-frequency heaters, but also because the weight can be detected, the heating time can be adjusted depending on the object to be heated 1. This makes it possible to improve cooking performance.

By the way, the elastic limit of ordinary springs, such as the leaf spring 5 used in the Roberval mechanism 7, decreases when the ambient temperature in which they are used becomes high, so although it depends on the material used, the weight detection performance may be affected. To ensure reliability, the operating atmosphere temperature must be kept low. Therefore, as in this embodiment, the lid 26
By providing an opening 25 in the opening 25 to draw in the cold air from outside, and providing a passage that flows around the Roberval mechanism 7 and exits to the side of the heating chamber 2 through the opening 23 provided in the fixing bracket 4, the inside of the heating chamber 2 can be drawn in. Even if the temperature reaches a high temperature due to the electric heating device 27, the Roberval mechanism 7
The ambient temperature can be kept low and reliability can be improved.

Furthermore, since the Roberval mechanism 7 is attached to the bottom surface 3 of the heating chamber 2 via the fixing metal fitting 4, it is possible to suppress conduction heat from the heating chamber 2, thereby further improving reliability. .

Effects of the Invention As described above, according to the present invention, the following effects can be obtained.

(1) The stable weight detector mounting structure provides highly accurate weight detection performance, eliminating the need for users to measure weight and greatly improving reliability.

(2) It can be constructed at low cost because only the fixing plate or the bottom surface has a strong structure.

(3) Since the structure is highly reliable against heat, heat sources such as electric heating devices can be used.
It can be applied to a wide range of cooking.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the lower part of the heating chamber of a high-frequency heater according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the lower part of the heating chamber of a high-frequency heater according to a second embodiment of the present invention. FIG. 3 is a diagram showing the bottom surface of the heating chamber of the second high-frequency heater of the present invention. Figure 4 shows
A- shown in FIG. 3 of the fixture of the second embodiment.
It is an A′ cross-sectional view. FIG. 5 is a sectional view of the lower part of the heating chamber of the high-frequency heater according to the third embodiment of the present invention.
FIG. 6 is an enlarged sectional view of the attachment part of the Roberval mechanism of the fixing fitting of the high-frequency heater according to the fourth embodiment of the present invention. FIG. 7 is a cross-sectional view of the lower part of the heating chamber of a high-frequency heater according to a fifth embodiment of the present invention. FIG. 8 is a cross-sectional view of the lower part of the heating chamber of a high-frequency heater according to a sixth embodiment of the present invention. 2... Heating chamber, 3... Heating chamber bottom, 4... Fixing metal fittings, 7... Roberval mechanism, 9... Mounting table, 1
0...Chiyoke, 13...Output control section, 14...
Magnetron drive unit, 15... Magnetron, 1
9...Motor, 24...Bottom plate, 26...Lid,
27... Electric heating device, 30... Door body.

Claims (1)

[Scope of Claims] 1. A heating chamber that stores an object to be heated, a door body that opens and closes the opening of the heating chamber, a heating means that heats the object to be heated using high frequency waves, and a detector that detects the weight of the object to be heated. and a means for controlling the output of the heating means according to the detected weight, and a ring-shaped drawing part provided on the bottom surface of the heating chamber, and the length of the fixing plate for fixing the weight detector is controlled by the ring-shaped drawing part. A high-frequency heating device that is longer than the inner diameter of the processing part and has a configuration in which both ends of the fixing plate are fixed to a ring-shaped constriction part. 2. The high-frequency heating device according to claim 1, wherein a part of the bottom surface of the heating chamber is made of another sheet metal. 3. The high-frequency heating device according to claim 1, wherein the weight detector is equipped with a drive unit to rotate the object to be heated. 4. The high-frequency heating device according to claim 1, wherein the fixing plate of the weight detector is provided with a nut, and the weight detector is fixed with a machine screw. 5. The high-frequency heating device according to claim 1, which is configured to include heating means other than high-frequency heating means. 6. The high-frequency heating device according to claim 1 or 5, wherein the heating means other than the high-frequency heating means is an electric heating device. 7. The high-frequency heating device according to claim 1 or 6, wherein a ring-shaped constriction portion is provided on the bottom surface of the heating chamber, and an electric heating device is inserted into the constriction portion. 8. The high-frequency heater is equipped with an intake port for sucking air from the outside on the bottom surface, and a ventilation port configured on the side surface of the fixing plate to which the weight detector is attached, so that the intake air passes around the weight detector and enters the side surface of the heating chamber. The high frequency heating device according to claim 1, wherein a flowing passage is formed.