JPS611927A - Electronic control type cooking apparatus - Google Patents

Abstract

PURPOSE:To prevent the temperature indication from being interrupted by gradually increasing the temperature in accordance with the temperature gradient determined based on the counted time upon the heating operation for a desired period of time to indicate the temperature. CONSTITUTION:When a microwave heating of a provision 2 based on the detected temperature of the provision 2, a shutter 22 is opened, and infrared rays from the provision 2 are incident on a senser 17. In this case, the senser 17 and the like are cooled, and a part of cooling air is introduced into a heating chamber 3 throgh an opening 14 and a ring 13, and the residual part is exhausted to the outside through a lower port 24 of an outer box 15. During the heating operation for a desired time, the temperature of the provision 2 is not directly detected by the senser 17. However, the pseudo-temperature is increased by a predetermined value at every counted time and is indicated in the temperature indicating part 7. In this case, the temperature rise gradient of the pseudo-temperature increased by a predetermined value is determined based on the every counted time during the temperature heating operation.

Description

[Detailed description of the invention] (, f) Industrial application field The present invention relates to an electronically controlled cooking device such as a microwave oven.

(b) Prior art In recent years, an infrared sensor has been placed above the outside of the heating chamber, and the sensor receives infrared rays from the food through openings formed in the earthen wall of the heating chamber. Microwave ovens have been commercialized that detect the temperature of food and control heating operation based on the temperature at which the food is rejected. In such a microwave oven, as seen in Japanese Patent Publication No. 56-42808, a shield for opening and closing the opening is provided, and the opening is closed by the shield at least when the temperature is not detected, thereby heating the food. Floating objects such as water vapor and food particles generated from the sensor are prevented from rising through the opening, thereby preventing the sensor from being contaminated by such floating objects as much as possible.

Therefore, in such a microwave oven, for example,
As seen in Publication No. 10113, in the case of cooking in which the temperature heating operation is first performed based on the temperature detected by the above-mentioned sensor, and then the heating operation is continued for a desired time,
During the temperature heating operation, the opening is fully opened and the food temperature is detected, and during the desired time heating operation, the opening is closed by a shutter.

In addition, when the above opening is open, if air is blown into the heating chamber through the above opening, floating objects will be prevented from rising through the above opening as much as possible even during temperature heating operation, and the sensor will be less likely to get dirty. This is even more significantly prevented.

Furthermore, when temperature is detected, the detected temperature is normally displayed on the temperature display section. However, in this case, when cooking as described above, the temperature cannot be detected once the timer operation has started, so the temperature display can be interrupted in the middle of cooking, which is extremely unnatural and causes the cook to suspect that the temperature display has malfunctioned. This may lead to the misunderstanding that this is not the case.

(/・) Public Purpose The purpose of the present invention is to close the opening in the wall of the heating chamber, which allows the infrared rays received by the sensor to pass through, with a shield when non-temperature detection is performed, in order to prevent the infrared sensor from becoming contaminated. The objective is to prevent the temperature display from being interrupted and becoming unnatural in certain situations.

(d) Structure of the Invention In order to achieve the above object, the present invention provides a heating chamber for storing food, a heating means for heating the food, and a heating device formed on the wall surface of the heating chamber outside the heating chamber. an infrared sensor for detecting the temperature of the food by receiving infrared rays from the food through the aperture, a temperature display section, a shutter for opening and closing the aperture, and a temperature heating operation based on the temperature detected by the sensor. and a control section that then closes the opening with the shutter and performs a heating operation for a desired time, and the control section causes the temperature detected by the sensor to be displayed on the display section during the temperature heating operation. At the same time, the time required for the detected temperature to pass through the specific temperature range is counted, and during the heating operation for the desired time, the temperature is increased one by one according to the temperature gradient determined based on the counted time, and the display section is displayed. It can be configured to display the temperature.

(E) Example A microwave oven according to an embodiment of the present invention will be described below.

Figure 1 shows the external appearance of the isobaric microwave oven, and shows the microwave oven body (
A heating chamber (3) for storing food (2) is arranged inside the main body (1), and a heating chamber (3) is arranged in the front part of the main body (1).
), and a door (4) that opens and closes the front opening of the front panel (
5) is provided. The panel (5) has a keyboard (6) consisting of various keys for setting cooking conditions, etc., and a fluorescent temperature display section (7).

Figure 2 shows the main parts of the microwave oven.
) is supplied with microwaves from a magnetron (9) as a food heating means through a waveguide (8), and the microwaves are covered with a microwave-transparent cover (10),
-7 The magneto from the Gnetron blower (11) is stirred by the rotating Stark (12) by the wind after cooling the magnetron. The stark is pivoted on a microwave isolation ring (13). Such a ring is caulked and fixed to the opening (14) formed in the upper wall (3a) of the heating chamber (3), and while it blocks the passage of microwaves, it also blocks the passage of infrared rays from the food (2). is now allowed.

Then, outside the heating chamber (3), the upper wall of the heating chamber (3a
>A metal outer box (15) is fixed on the top, and a metal inner box (16) is fixed inside the outer box. An infrared sensor (17) and a temperature circuit board (18) for processing the output of the sensor are arranged. Inner box above (16)
There is a small hole (19) opposite the sensor (17) in the lower wall of the
is formed. The sensor (17) receives infrared rays from the food that is guided through the ring (13), the opening (14), and the small hole (19) of the inner box (16), thereby detecting the temperature of the food. Microwave heating, which will be described later, is controlled based on the detected temperature.

Furthermore, inside the outer box (15) is a sensor blower (20).
The cooling air generated from the is guided through the ventilation duct (21>).When this cooling air is led into the outer box (15), the inner box (
16) Substantially the inner box (16) by passing around the periphery
The sensor (17) and temperature circuit board (18) inside are cooled. In addition, inside the outer box (15) there is an upper wall of the heating chamber (1).
3a> to the upper opening of the ring (13) are provided. The shutter is normally held in a closed state by a spring or the like, and is opened when the solenoid <23) is energized.

Therefore, when the temperature of the food (2) is not detected, the shutter (22) is in a closed state, and floating objects such as water vapor and food particles generated from the microwave-heated food (2) are trapped in the opening (2). 14), the sensor (17) is reliably prevented from rising through the ring (13) and exiting the heating chamber (3).
> etc. are significantly prevented from getting dirty. In this case, in a state where microwave heating is performed by timer time etc. (described later), the sensor (1
7) etc. are performed by cooling air from the sensor blower (20), and the latter cooling air is exhausted to the outside from the lower opening (24) of the outer box (15).

Next, when the temperature of the food (2) is detected and microwave heating is performed based on the detected temperature, the shutter (22) is opened and the sensor (17) receives infrared rays from the food (2) as described above. is incident. Furthermore, in this case, the sensor (17) etc. are cooled, and a part of the cooling air is then sent into the heating chamber (3) through the opening (14) and the ring (13), and the rest is sent into the heating chamber (3). Lower opening (2) of outer box (15)
4) Exhaust air can be exhausted to the outside. In this way, when a part of the cooling air is sent into the heating chamber (3) through the opening (14) and the ring (13), the air is generated from the food (2) during heating. Floating objects are prevented from rising through the gap Q (14) and the ring (13) and coming out of the heating chamber (3) as much as possible, thereby preventing soiling of the sensor 17) and the like.

FIG. 3 shows the circuit of the microwave oven. A microcomputer (25) is provided as a control section, and the operation of the microwave oven is controlled by the computer. That is, the computer (25) inputs the cooking conditions etc. from the keyboard (6) and also inputs the temperature of the food 7 detected by the sensor (17°) via the A/D converter (26). Based on this information, on/off of the first to fourth switching circuits (27a) to (27d) including triacs and the like is controlled. When the first switching circuit (27a) is turned on, a well-known high voltage circuit (27a) consisting of a high voltage transformer (28) etc.
9) is fully supplied with electric power from the commercial type FI (30), and as a result, high voltage is supplied to the magnetron (9) and microwave heating is performed. In addition, the second switching circuit (27
When b) is turned on, power is supplied to the magnetron blower (11), the magnetron (9) is cooled and the starter (12) is rotated, and the third switch and turning circuit (
27c) is turned on, power is supplied to the sensor blower (20) to cool the sensor (17), etc., and if the shutter <22) is open, the opening (14) and the ring (1
When floating objects are prevented from rising through the solenoid (3) and the fourth switching circuit (27d) is turned on, the solenoid (
23) is energized to open the shutter (22). Furthermore, the computer (25) has a temperature display section (
Temperature display control is performed in step 7>.

18= Next, the operation of the microwave oven will be explained along with the flowchart of the program of the computer (25) shown in FIG.

Normally, a program cycles through the Sl and S2 steps. In step S1, a cooking course as a cooking condition selectively set using the keyboard (6>) is input, and in step S2, it is determined whether or not a cooking start operation has been performed using the keyboard (6).

For example, as seen in Japanese Patent Publication No. 55-10113, the temperature heating operation is performed until the temperature detected by the sensor (17) reaches the desired low heating temperature, and then the heating operation is continued for a desired period of time. When a cooking course to be carried out is selectively set, the contents of the course are input into the computer 25). When the cooking start operation is performed, the program advances to step S3. In step S3, it is determined whether or not the cooking course inputted in this manner is one in which a temperature heating operation is followed by a time heating operation. In this case, since the time heating operation is performed after the temperature heating operation, the program advances to step S4. If the result in step S3 is negative, the program proceeds to a step for performing other appropriate processing, which will not be described in this embodiment.

Then, in step S4, the first to fourth switching circuits (27a) to (27d) are started to turn on, opening the shutter (22) as described above, driving the magnetron blower (11), and driving the sensor blower (20). ) and microwave heating are started. Thereafter, temperature heating operation is performed. In the subsequent step S5, the temperature obtained by subtracting 5°C from the low heating temperature in the temperature heating operation of the second cooking course is written to the temperature register TEMP in the computer (25), and the temperature in the computer (25) is written. Counter RCNT and flag FLG are cleared. In the next step 86, it is determined whether 1 is written in the flag FLG. In this case, it is 0, so P
7 grams then goes through steps S7, S8, and S9. S
In step 7, the temperature detected by the sensor (17) is input, in step S8, the detected temperature is displayed on the temperature display section (7), and in step S9, the detected temperature is written to the temperature register TEMP. It can be determined whether the specified temperature has been reached.

Thus, the program cycles through steps 86 to S9, after which heating progresses and the detected temperature reaches the temperature register TE.
When the temperature at MP is reached, step S10 is reached. In this step, 1 is written to the flag FLG.

In the next step 811, the detected temperature in step S7 is the low heating temperature (
It is then determined whether this temperature has reached 5° C. higher than the temperature in the temperature register TEMP. In the present case, no such arrival is made and the program then returns to step S6. However, in this case, since the flag FLG is 1, the program then proceeds to step S12.

In this step, the counter RC in the computer (25)
Timing starts at NT. Next, the program is 87
~After going through the Sll step, S6, S12.87~81
It will cycle through one step.

When the heating progresses further and the temperature detected in step S7 reaches the low heating temperature, the program goes to step 813.
Reaching the steps. At this point, the temperature heating operation has ended. Then, in step 913, the counter RCNT stops measuring time. In this case, the counter RCNT counts the time required for the detected temperature to pass through a specific temperature range from (low heating temperature -5°C) to (low heating temperature) during the temperature heating operation. . In the following step S14, the fourth switching circuit (2
7d) is turned off and the shutter (22) is closed as described above to ensure that floating objects do not rise and pollute the sensor (17) and the like.

Thereafter, a time heating operation is performed. First, in step S15, the desired time in the time heating operation of the cooking course is set by the timer counter TCNT in the computer (25).
The counter TCNT decrements its contents every second. In the following step 816, the contents of the counter RCNT are also written to a counter CNT in the same computer (25), and the contents are similarly decremented every second in the counter. The program then cycles through step 817.81g, S19. At step 817, the temperature is displayed in the temperature display section 7). In this case, the temperature display section (7) displays the detected temperature that was input last at step S7 in the temperature heating operation. In steps 91g and S19, it is determined whether the contents of the timer counter TCNT and counter CNT have become 0, respectively.

Therefore, the contents set in the counter CNT are considerably smaller than the contents set in the timer counter TCNT, and of course the contents of the counter CNT become 0 first during the above-mentioned circulation. When the content of the counter CNT becomes O, the program exits the cycle of steps S17, 518 and S19 at step 819 and reaches step S20. In this step, the temperature value displayed in step 817 is increased by a predetermined value. The program then returns to step S16, and the contents of the counter RCNT are written into the counter CNT again. Then, a similar cycle of steps 817, S18, and 819 is performed. In this case, the temperature display at the 517 step is the 320 step above.
The temperature value increased by a predetermined value in the step is displayed. Therefore, when the contents of the counter CNT become 0 again, 3
At step S17, the temperature value displayed at step S17 is further increased by one predetermined value.

In this way, during the heating operation for such a period of time, the temperature of the food (2) is not directly detected by the sensor (17), but the pseudo temperature of the large hole is detected by the count counted by the counter RCNT. The temperature is increased by a predetermined value every time and displayed on the temperature display section (7). Here, in the pseudo temperature which is increased by a predetermined value at each count time, the temperature increase gradient is determined based on the count time during the temperature heating operation. Thus, for example, the counting time is about 30 seconds to 1 minute, and the predetermined value of the temperature to be increased is selected to be a constant value between 5 and 10''C.

After that, when the content of timer counter TCNT becomes 0,
The program exits the cycle of steps S17, 818, and 819 at step 818 and reaches step S21. In this step, the first to third switching circuits (27a) to (2
7c) is turned off, the microwave heating is not stopped, and the time heating operation is ended, thereby completing the cooking of the above course, and the magnetron blower (11) is turned off.
) and the sensor blower (20>) are stopped.Then, the program enters a state in which it cycles through steps S1 and S2 without waiting for the next key operation for cooking.

In the above embodiment, the temperature display on the temperature display section (7) may be digital or analog.

Furthermore, in the above embodiment, the temperature display section (7) displays the detected temperature and the pseudo temperature as they are, but the final temperature at the end of cooking is assumed to be 100, and the ratio of the detected temperature and pseudo temperature to that is calculated, Such a ratio may be displayed as a representative of the detected temperature and the pseudo temperature.

(f) Effects of the Invention According to the present invention, a temperature heating operation is performed based on the temperature detected by an infrared sensor, and after that, in order to prevent the sensor from becoming dirty, an opening is formed in the heating chamber wall surface through which infrared rays received by the sensor pass. In a cooking device that closes with a shutter and performs heating operation for a desired time, the temperature detected by the sensor is displayed on the temperature display section during the temperature heating operation, and the temperature required for the detected temperature to pass through a specific temperature range is displayed. The time is counted, and during heating operation for the desired time, the temperature is sequentially increased according to a temperature gradient determined based on the counted time and the temperature is displayed on the display section, so that the temperature display on the temperature display section is interrupted. Therefore, the unnaturalness of the temperature display can be eliminated, and the cook does not have to misunderstand that the temperature display is malfunctioning.

Further, the time required for the detected temperature to pass through the specific temperature range, that is, the counting time, becomes longer or shorter depending on the amount of food, for example, and the temperature gradient becomes smaller. As a result, the temperature display section during the heating operation for the desired time increases gradually or sharply in the same way as the actual temperature rise, depending on the amount of food. It is possible to display a temperature display that more closely follows the actual food temperature without being affected by the temperature of the food.

[Brief explanation of drawings]

The drawings show a microwave oven according to an embodiment of the present invention; FIG. 1 is an external perspective view, FIG. 2 is a cross-sectional view of essential parts, FIG. 3 is a circuit diagram, and FIG. 4 is a broach route of a microcomputer program. (3)...Heating chamber, (7>・Temperature display section, (9)・
Magronetrobi・, (14)・・Opening, (17)・Infrared sensor, (22>・Shutter, (25>・・Microcomputer).

Claims (1)

[Claims] (1) A heating chamber for storing food, a heating means for heating the food, and receiving infrared rays from the food through an opening formed in the wall of the heating chamber outside the heating chamber to measure the temperature of the food. An infrared sensor for detection, a temperature display section, a shutter for opening and closing the opening, and a temperature heating operation is performed based on the temperature detected by the sensor, and then the shutter closes the opening and operates for a desired time. A control unit for performing heating operation, the control unit including:
During the temperature heating operation, the temperature detected by the sensor is displayed on the display section, and the time required for the detected temperature to pass through a specific temperature range is counted. During the heating operation for the desired time, the temperature is determined based on the counted time. An electronically controlled cooking appliance characterized in that the temperature is sequentially increased according to the determined temperature gradient and the temperature is displayed on the display section.