JPS61149732A - Microwave heating and cooking unit with sensor - Google Patents

Abstract

PURPOSE:To strike low speed air flow containing vapour to a humidity sensor part and to make a positive humidity sensing operation by a method wherein a partition plate in the discharging duct is opened when an infrared ray sensor is operated and the vapour phase near the surface of the food is discharged into the discharging duct rapidly and in turn when the humidity sensor is operated, the partition plate is lowered. CONSTITUTION:When a cooking operation is being performed while an infrared ray sensor 2 detects a surface temperature of food 3, a partition plate 8 in a discharging duct 6 is raised up to decrease the resistance of air flow from within the heating chamber 1 to the surrounding atmosphere, the vapour fed out of the food 3 is discharged at once through discharging punched holes 10a and the discharging duct 6 and to the surrounding atmosphere. In turn, when the cooking is performed while the humidity sensor 7 detects the vapour fed from the food 3, the partition plate 8 in the discharging duct 6 is lowered, a mintangled passage is formed in the discharging duct 6 to increase a resistance in the air flow passage. With the foregoing, the air containing vapour is passed slowly through the himidity sensor 7, resulting in that the humidity sensor 7 may perform a positive sensing of humidity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a high frequency cooking device with a senna.

2. Description of the Related Art In a conventional cooking device with an infrared sensor, such as a microwave oven, as shown in FIG.
The configuration was such that the surface of food 3 could be viewed from b. However, the infrared sensor 2 detects infrared radiation from the surface of the food 3 to determine the temperature of the food, and if the surface of the food is covered with steam from the food, it will not be possible to measure the temperature of the steam correctly. There was a risk that temperature detection would not be possible. In order to avoid such a situation, in a conventional microwave oven equipped with an infrared sensor,
As shown in FIG. 1, the wind noise generated by the cooling fan 6 of the magnetron 4 is placed inside the heating chamber 1, and the exhaust duct 6 from the heating chamber 1 to the outside is also made relatively large. It was common practice to expel the steam quickly and to prevent the surface of the food 30 from being covered with steam. On the other hand, the infrared sensor 2 is used when the surface of the food 3 is covered with a plastic film, a tableware lid, etc.
As shown in Figure 0, if the infrared sensor 2 falls out of the field of view in synchronization with the rotation of the turntable 3&, the temperature of the food cannot be detected correctly.

The normal food position and changes in detected temperature are shown in Figures 12 and 13, respectively. Therefore, in a state where the infrared sensor 2 cannot detect the change, a composite sensor including an infrared sensor and a humidity sensor is used, which detects changes in the amount of steam emitted from the food 3 and uses a humidity sensor placed in the exhaust duct as a sensor to know the heating state of the food. A microwave oven with a built-in microwave oven is considered. However, the humidity sensor
Humidity cannot be detected unless the food is exposed to steam for a certain period of time, so the exhaust duct 6 is installed as shown in Figure 13.
Normally, the exhaust duct 6 is made small so that the steam can pass through the humidity sensor 7 slowly.

Problems to be Solved by the Invention As mentioned above, in a cooking appliance equipped with an infrared sensor and a humidity sensor, simply adding another sensor to the configuration of the heating chamber with the air passage configuration suitable for either sensor will cause problems in both sensors. There was a problem that the characteristics could not be brought out.

The present invention solves the problem of the conventional @, and the above-mentioned 2
The purpose is to realize the optimal air path configuration for each sensor by changing the air volume and air pressure when detecting the heating state of food using each sensor.

Means for Solving the Problems In order to solve the above problems, the sensor-equipped cooking appliance of the present invention has an infrared sensor and a humidity sensor, a means for selecting both sensors, and a magnetron when each sensor is selected. It has a configuration in which the size of the inlet of the cooling air into the heating chamber can be made variable and the position of the partition plate within the exhaust guide can be changed.

Effect of the Invention With the above-described configuration, when the infrared sensor operates, the infrared sensor On the other hand, when the humidity sensor is working, the barrier board inside the exhaust duct is lowered to increase the exhaust resistance, and the humidity sensor placed at the back of the maze inside the exhaust duct Embodiments Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

When cooking is being carried out while the infrared sensor 2 detects the surface temperature of the food 3 in the first prisoner, the partition plate 8 in the exhaust duct e is positioned at the position shown by the dotted line, and the air is passed from inside the heating chamber 1 to the outside. The structure is such that the steam coming out of the food 3 is immediately exhausted to the outside through the exhaust punching 102L and the exhaust duct 6 by reducing the resistance of the air flow. For this reason, the steam emitted from the food 3 does not stay in the heating chamber 1 and therefore does not cover the food 3, so the infrared sensor 2 can correctly detect the radiation from the food 3 and accurately measure the temperature. be.

On the other hand, when cooking is performed while the humidity sensor 7 detects steam from the food 3, the partition plate 8 in the exhaust duct 6 is positioned at the position shown by the solid line to form a maze of steam in the exhaust duct e and prevent airflow. road resistance is increased. This allows the steam-laden wind to pass slowly through the humidity sensor 7, which has the effect of allowing the humidity sensor 7 to detect humidity reliably.

Next, a second embodiment of the present invention will be described using FIG. 2.

The wind generated by the cooling fan 6 of the magnetron 4 is
The air is guided by the air guide 9 and enters the heating chamber 1 through the punched portion 1o of the side wall of the heating chamber 1. A shutter plate 11 is installed inside this air guide 9, and an infrared sensor 2't
When the humidity sensor 7t is used to control the heating of the food 3, it is located at the position indicated by the dotted line, and when the humidity sensor 7t is used to control the heating of the food 3, it is located at the position indicated by the solid line. In Figure 2,
By adjusting the amount of air flowing into the heating chamber 1, the amount of air inside the heating chamber 1 and the exhaust duct 6 can be controlled.

It goes without saying that if the configurations shown in FIG. 1 and FIG. 2 are implemented at the same time, the configuration will still have the effect of varying the air volume.

FIG. 3 shows an embodiment of the control circuit of the present invention including the drive control circuit for the above-mentioned partition plates 8 and 11. In FIG. In FIG. 3, the microcomputer 12 (hereinafter referred to as microcomputer) sequentially outputs the scanning pulses shown in FIG. To check. Here, the infrared sensor detection key 14a, humidity sensor detection key 14b1 and automatic key 140 are activated when SO is High.
This can be known by detecting that Is, I2, and 11 are Hi (h), respectively. DO
to D6 are parallel outputs for displaying segments on the display section 13 shown in FIG.

R1 to R7 of the microcomputer 12 are individual output terminals, and R
1 is connected to the magnetron circuit 1 via the driver IC 20.
relay 19 which controls 8. R2 is a terminal that controls the supply of power supply voltage to the magnetron circuit 18, cooling fan motor 21, and turntable motor 2 via the driver IC 201.ORs controls the entire buzzer circuit 16 for confirming the completion of cooking and key input. It is a terminal. R4 and R5 are the partition plates 11 inside the air guide 9 on the intake side.
The terminals oR6 and R7 for moving the step motor 11 & to a predetermined position are connected to the shim plate 82 in the exhaust duct 6. il - This is a terminal for moving the step motor 8 to a predetermined position. Also, the signal detected by the infrared sensor 2 is sent to the microcomputer 12 via the amplifier 2ai.
The temperature is taken into the microcomputer 12 from the D+ terminal and calculated to determine the food temperature. On the other hand, the humidity signal generated by the humidity sensor 7 and the dividing resistor 7a is
The humidity level is taken into the microcomputer 12 from the terminal and determined by calculation.

Here, an example of the operation of the microcomputer 12 when the automatic key 140 is pressed will be explained based on the flowchart of FIG. Heat the food from a constant temperature, and (a) If it is detected that the measured value is at the local maximum point, the measured value is set to the maximum value. shall be. (c)
When the difference between the maximum value and the minimum value becomes larger than two constants,
b) It is determined that the infrared output is fluctuating in a vibrational manner and the vibration flag is set to 1. When the vibration flag is set to 1, no further detection is performed by the infrared sensor, and (e) only detection by the humidity sensor is performed.0 Also, when detection is performed only by the humidity sensor, R7 in Figure 3 is output, The partition plate 8 is closed. On the other hand, the vibration flag is 1
R6 is output while it is not set to 8
is kept open.

According to the control flow described above, even if the food 3 changes position as shown in FIG. 9 (at, e) during heating and the infrared sensor 2 cannot detect the surface temperature of the food 3, the humidity remains The heating state of the food can be known by the sensor 7,
Moreover, since the configuration of the air passage is suitable for detection by the humidity sensor 7, it is effective not only as a safety device for simply preventing overheating of food, but also in detecting the excellent quality of the food.

Effects of the Invention As described above, the sensor-equipped cooking appliance of the present invention provides the following effects.

(1) When using the infrared sensor and humidity sensor, the air passage configuration is optimized for each.
The detection accuracy of the sensor is good0 (2) The two sensors detect the heating state of the food in the optimal state, so it is safe because it can detect before the heating chamber becomes in a dangerous state such as burning the food due to overheating. will improve.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a high-frequency heating cooker with a sensor according to the first embodiment of the present invention. A circuit diagram showing an example of the electronic circuit of the cooking device, FIG. 4 is an output timing chart of the scanning pulse of the microcomputer of the cooking device, and FIG. 6 is a diagram showing the structure of the display tube of the cooking device. A flowchart of the instruction execution of the microcomputer of the cooker, Fig. 7 is a sectional view of a conventional high-frequency heating cooker with an infrared sensor, Fig. 8 is a partially cutaway front view of the same, Fig. 9 ((transfer), (b) ), Figure 11 (Tsurunaka)
106 and 12 respectively show the same food placement position, (&) is an open sectional view, crest) is a front view of the food placement table, Fig. 106 and 12 are output views of the same infrared sensor, and Fig. 13 is a conventional and other FIG. 2 is a cross-sectional view of the high-frequency cooking device. 1... Heating chamber, 1b... Hole, 2...
...Infrared sensor, 4...Magnetron, 6
......Cooling fan, 6...Exhaust duct,
7... Humidity sensor, 8... Threshold ff board, sa... Step motor, 9... Air guide, 10... Punching section , 1oIL・
...Exhaust punching, 11...Block plate, 11a...Step motor, 12...
- Microcomputer, 14a...Infrared sensor detection key, 14b...Humidity sensor detection key, 14G...Automatic key. Name of agent: Patent attorney Toshio Nakao and one other person
・Kakuden 2, -T, outside line sensor 3...Original product No. 1 1! I6-, PI Note 7... 1 min. 8-... L-cut lθ... non-indicator) 1'a=JHt,>e>9->7 Fig. 4 Figure 6 Figure 7 4...721 Tron Figure 9 Calculation time Figure 11 (Q) (,6) Figure 12 Calculation M M M C4J-7

Claims (4)

[Claims] (1) A heating chamber in which food is placed, a high-frequency generating means for supplying high-frequency energy to the food in the heating chamber, a cooling fan for the high-frequency generating means, and an intake air duct that guides the air from the cooling fan into the heating chamber. and an intake punching part on the wall surface of the heating chamber, an exhaust punching part on the heating chamber wall surface that guides air from the heating chamber to the outside, an exhaust air passage communicating with the exhaust punching part, and an exhaust air passage installed in the exhaust air passage. A sensor equipped with a sensor, a hole provided in the ceiling of the heating chamber, an infrared sensor provided outside the ceiling, and an air volume changing means for changing the air volume in the heating chamber when the two sensors are used. (2) The sensor-equipped high-frequency heating cooker according to claim 1, wherein the air volume changing means in the heating chamber comprises a partition plate provided in the intake air path and a drive device for the partition plate. (3) The sensor-equipped high-frequency heating cooker according to claim 1, wherein the air volume changing means in the heating chamber comprises a partition plate provided in the exhaust air path and a drive device for the partition plate. (4) When the food temperature cannot be detected by the infrared sensor while food is being heated, the food temperature detection is switched to the humidity sensor and the airflow in the exhaust air duct is reduced. The sensor-equipped high-frequency heating cooker according to claim 1 or 3, which is configured to move a partition plate.