JPH0365639B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a heater such as a microwave oven with a heater, and in particular to a heater for automatically setting and controlling the height of the heater according to the height of food. It is related to position control.

<Prior art> Conventionally, in a microwave oven equipped with a heater, when performing grill heating (the menu for browning fish, gratin, etc. is generally referred to as grill heating), the heater 1 must be manually moved up and down, or the heater 1 must be turned up and down as shown in Figure 6. By changing the voltage or changing the polarity of the electric motor 2A connected to the electric motor 1, the user can change the heater position according to the height of the food 7 on the device tray 3 in the cooking chamber 5. was set appropriately. However, since the user sets the heater position, the user may forget to bring the heater 1 close to the food 7 and the food 7 may not be burnt, or the heater position may be inappropriate and the food 7 may be under-heated or over-burned. As a result, there were large variations in the finish of the food 7, and the operation of setting the heater position was troublesome.

<Objective> In view of the above, the present invention provides a heating system that detects the height of food on a device tray in a cooking chamber by using a height detection sensor, and automatically sets a heater according to the food height. The purpose is to provide equipment.

<Example> An example of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a front view showing a schematic structure of a microwave oven which is an embodiment of the present invention. In this microwave oven with a heater, a heater 1 is installed in a cooking chamber 5 so that its height can be freely adjusted, and an adjustment drive device 2 for adjusting the height of the heater 1 is provided in the cooking chamber 5. A device tray 3 for storing food 7 is installed rotatably around a rotating shaft 8, and a rotation drive device 9 for rotationally driving the device tray 3 is provided, and the adjustment drive device 2 and the rotation drive device 9 A plurality of height detection sensors 11 for detecting the height of the food 7 in the cooking chamber 5 are arranged vertically on the wall of the cooking chamber, and the control device 10 includes: The rotary drive device 10 is driven to rotate the device tray 3 by 180 degrees or more, the height of the food 7 is detected based on the output signal of the height detection sensor 11, and a signal for controlling the adjustment drive device 2 is output. It is something that has a function.

The height detection sensor 11 is an optical sensor, and consists of a light emitting element 12 and a light receiving element 13. The light emitting element 12 is interposed between one side wall of the cooking chamber 5 and the heater main body 14 that houses the cooking chamber 5. A plurality of small holes 15 are formed in the side wall of the cooking chamber 5 at the same position as the light emitting elements 12. Further, the light receiving element 13 is arranged on the outside of the other side wall of the cooking chamber 5 facing the light emitting element 12 at the position (height) of the light emitting element 12.
A small hole 16 is formed in the side wall of the cooking chamber 5.

FIG. 2 is a schematic plan view of the microwave oven, in which the light receiving element 13 and the light emitting element 12 are
are arranged opposite to each other in point-symmetrical positions with respect to the axis A of the two. As the light emitting element 12, an oven lamp or a light emitting diode is used. As shown in FIG. 3, the light-receiving elements 13 are composed of phototransistors (a photodiode or the like can also be used), and the emitter side of each light-receiving element 13 is connected to the base side of a transistor 18. When light enters the light-receiving element 13, the transistor 18 is ON, transistor 1
The collector voltage of the transistor 8 is at L level (OV), and when no light enters, the collector voltage of the transistor 18 is connected to be at H level (+Vc). The signal level of each transistor 18 is then sent to the interface 22 of the main control circuit 21 of the control device 10.

FIG. 3 is a diagram showing the configuration of a control device, and the control device 10 includes a main control circuit 2 that controls the heater heating device B, the high frequency heating device C, and the rotation drive device
1 (microcomputer) and the main control circuit 2
1 includes a setting device 23 that outputs signals such as a selection key 23A and a cooking start key 23B, and the setting device 2
3 and the main control circuit 21 are connected via an interface 22.

The adjustment drive device 2 is composed of a DC motor 27 and a motor control circuit (IC) 25 that controls the motor to rotate, reverse, and stop, and signals for forward/reverse rotation and stop are sent to an interface 22.
It is output from the main control circuit 21 via.

The rotational drive device 9 includes a device pan drive motor 26.
, a relay switch 27a that turns on/off the motor 26, a relay coil 27b that operates the relay switch 27a, and a transistor 28 that drives the relay coil 27b with the output signal of the main control circuit 21. The relay switch 27a is connected to a power plug 30 via a door switch 29.

The heater heating device B includes a heater 1 and a relay switch 31a that controls ON/OFF of the heater 1.
, a relay coil 31b that operates the relay switch 31a, and a transistor 32 that drives the relay coil 31b by the output signal of the main control circuit 21.
1a connects the power plug 30 via the door switch 29
It is connected to the.

The high-frequency heating device C also includes an oscillation circuit 36 including a magnetron 4, a resonant capacitor 33, a diode 34, a transformer 35, etc., a relay switch 37a that conducts to the oscillation circuit, and a relay coil 37b that operates the relay switch 37a.
and a transistor 38 that drives the relay coil 37b by the output signal of the main control circuit 21, and the primary side of the transformer 35 and the relay switch 3
7a is the power plug 30 via the door switch 29
It is connected to the.

In addition, 39 in Figures 4 and 5 is a cooking net, which is
This is a special accessory that is used to drain the oil when grilling fish while heating the grill.

Next, the operation will be explained. First, press the grill key among the selection keys 23A of the setting device 23, select the menu, and then press the heating start key 23B.The main control circuit 21 operates the device pan drive relay coil 31b, closes the relay switch 27a, and closes the device pan drive relay coil 31b. Rotate 3.

Next, if the light emitting element 12 is made to emit light and there are a plurality of outputs from the transistors 18 that change according to the input to the light receiving element 13, that many "L" or "H" level signals will be sent. , read into the main control circuit 21. If detection is performed without rotating the food tray 3, detection may not be possible depending on where the food is placed.

Figures 4 and 5 show the food 7 actually being placed on the cooking net 39.
A schematic diagram (each figure a) when it is mounted on and operated,
FIG. 7 is a diagram (each diagram b) showing the output of the transistor 18 at that time. As shown in FIG. 4, if the food 7 reaches the light receiving element 13 without blocking the light from the light emitting element 12, the output of the transistor 18 becomes "L" level. As shown in FIG. 5, when the food 7 is high, light does not reach the light receiving element 13, and the output of the transistor 18 in the shaded area becomes "H" level. As the device tray 3 rotates, light is emitted or not emitted, so the output often shifts between "L" and "H" levels as shown in FIG. 5B.

Therefore, the main control circuit 21 reads the output of the light receiving element 13 until the device pan 3 rotates 180 degrees. Then, it is checked which of the plurality of light receiving elements 13 has reached the "H" level at least once, and if there is a light receiving element 13 that has reached the "H" level at least once, the height of that light receiving element 13 is determined. indicates that the food 7 is at the corresponding height. Therefore, if the heater 2 is lowered to the position of the light receiving element 13 that has reached the "H" level, the heater 2 will hit the food 7, so the main control circuit lowers the heater 2 to the position of the light receiving element 13 directly above it. 21 sends a signal to the control circuit 25 of the adjustment drive device 2 to rotate the DC motor 24 and lower the heater 2. When the detected heater height is reached, the main control circuit 21 outputs a stop signal to the control circuit 25 in the same manner as described above.
Stop the motor 24.

Next, the main control circuit 21 controls the heater relay coil 3
1b is operated to operate the relay switch 31a to turn on the heater 2 and perform grill heating to brown the food 7. Then, after a certain period of time has elapsed, the main control circuit 21 controls the motor control circuit 25 so that the heating is stopped and the heater 1 is automatically returned to its original position (upward).
send a signal to.

It should be noted that the present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention. For example, in this embodiment, the sensor is an optical sensor, but a sensor that utilizes reflection of ultrasonic waves or the like may also be used.

<Effects> As is clear from the above description, the present invention provides a heater in which a heater is installed in a cooking chamber so that its height can be freely adjusted, and an adjustment drive device for adjusting the height of the heater is provided. A device tray for placing food in the cooking chamber is rotatably installed around a rotating shaft, a rotational drive device is provided to rotationally drive the device tray, and a control is provided to control the adjustment drive device and the rotational drive device. A device is provided, a plurality of height detection sensors for detecting food and height in the cooking chamber are arranged vertically on the wall of the cooking chamber, and the control device drives the rotary drive device to move the device tray. is rotated by 180 degrees or more to detect the height of the food based on the output signal of the height detection sensor, and
This invention relates to a heater characterized in that it has a function of outputting a signal for controlling.

That is, the present invention uses a plurality of height detection sensors, detects the height of the food according to the output from the sensors,
The heater is controlled to a predetermined height, and the food height is determined by rotating the device tray over 180 degrees and reading the output of the height detection sensor during that time. Since the device tray rotates no matter where it is placed, the height detection sensor always detects it somewhere, so the food height can be detected well without malfunctions, and it can be done with a simple operation of rotating the device tray, so it is inexpensive. There are many benefits such as being able to do this.

[Brief explanation of drawings]

Fig. 1 is a front view showing a schematic structure of a microwave oven which is an embodiment of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a diagram showing the configuration of a control device, Figs. 4a and 5. Figure a is a schematic diagram of when food is actually placed on a cooking grid and operated, Figures 4b and 5b are diagrams showing the output of the transistor at that time, and Figure 6 is a schematic diagram of a conventional microwave oven. It is a front view. 1: Heater, 2: Adjustment drive device, 3: Device tray,
5: Cooking room, 7: Food, 8: Rotation shaft, 9: Rotation drive device, 10: Control device, 11: Height detection sensor.

Claims (1)

[Claims] 1 A heater is installed in the cooking chamber so that its height can be adjusted freely.
In the heater provided with an adjustment drive device for adjusting the height of the heater, a device tray for placing food in the cooking chamber is rotatably installed around a rotation axis, and the device tray is rotationally driven. A rotary drive device is provided for controlling the adjustment drive device and the rotation drive device, a control device is provided for controlling the adjustment drive device and the rotation drive device, and a height detection sensor for detecting the height of the food in the cooking chamber is installed vertically on the wall of the cooking chamber. The control device drives the rotary drive device to rotate the device tray.
A heater characterized in that it has a function of detecting the height of food by rotating it by 180 degrees or more using an output signal of the height detection sensor and outputting a signal for controlling the adjustment drive device 2.