JPH0527012B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a cooking device that can purify a heating chamber by dry-firing it at an appropriate time.

(b) Conventional technology Conventionally, in a cooking device that heats food using a heater, for example, if the heating chamber is used with oil droplets, food particles, etc. scattered from the food adhering to the wall surface of the heating chamber during heating, the heating chamber will be damaged. The oil droplets, food particles, etc. adhered to the walls of the heating chamber, and therefore, it took a considerable amount of effort and time to clean the walls of the heating chamber afterwards.

Therefore, in recent years, cooking appliances in which a self-cleaning coating layer is formed on the wall surface of the heating chamber have been commercialized. In such a cooker, oil droplets, food particles, etc. scattered from the food during heating adhere to the coating layer, but in this case, due to the catalytic action of the coating layer together with the heat from the subsequent heating of the food with the heater, The adhering oil droplets, food particles, etc. are decomposed into water and carbon dioxide and are naturally removed. Therefore, the labor and time required for cleaning the heating chamber wall surface as described above can be eliminated. However, even in cooking appliances with such self-cleaning coating layers, it is difficult to completely remove oil droplets, food particles, etc. that adhere to the coating layer, and therefore, after long-term use, The coating layer is covered with oil droplets, food scraps, etc., resulting in a situation in which the coating layer cannot exhibit catalytic action.

Therefore, in response to these problems, the special public
As seen in Publication No. 29775, a dirt sensor is provided on the heating chamber wall surface to detect the degree of dirt on the heating chamber wall surface,
A cooking appliance has been proposed that, when the sensor detects a predetermined degree of contamination, automatically performs its own dry firing operation to sufficiently decompose and remove oil droplets, food particles, etc. adhering to the coating layer. However, such a cooking appliance has the disadvantage that the configuration including the dirt sensor is complicated and expensive.

(c) Problems to be Solved by the Invention Therefore, it is possible to eliminate dirt from a heating chamber in which a self-cleaning coating layer is formed on the wall surface using a simple structure that eliminates the dirt sensor described above without complicating the structure. It would be good if you could get a cooker that can reliably run dry cooking once it has reached a certain level.

(d) Means for solving the problem The cooking device includes a heating chamber in which a self-purifying coating layer is formed on the wall surface and in which food is stored, a heating energy generating means for applying heating energy to the food in the heating chamber, A counter for counting a predetermined signal when the cooker is used, a changing means for changing the generation cycle of the predetermined signal based on the temperature in the heating chamber, and a dry firing operation should be performed when the count value of the counter reaches a predetermined value. The present invention is characterized by comprising a dry firing instruction section that gives instructions.

(E) Effect When the heating chamber with the self-cleaning coating layer formed on the wall becomes dirty to some extent, the count value of the counter reaches a predetermined value, and the air-fuel instruction section issues an air-firing operation instruction. Given. Moreover, in view of the fact that the degree of contamination of the heating chamber changes based on the heating chamber temperature during heating, the generation cycle of the predetermined signal counted by the counter is changed based on the heating chamber temperature. There is. Therefore, the count value of the counter closely matches the degree of contamination of the heating chamber, and air firing operation can be performed accurately at the time when air firing is required. Furthermore, the need for a conventional dirt sensor can be eliminated.

(f) Examples The drawing shows a cooking device according to an embodiment of the present invention.

1 and 2 are an external perspective view and a cross-sectional view of the cooking device, respectively. A heating chamber 2 for storing food is arranged inside the cooking device main body 1, and a heating chamber 2 for storing food is arranged in the cooking device main body 1. A door 4 and a front panel 5 for opening and closing the front opening 3 of the heating chamber 2 are arranged. A heater 6 for applying heating energy to food is provided at the upper part of the heating chamber 2, and a self-cleaning coating layer 7 is formed on the upper wall 2a of the heating chamber 2 corresponding to the heater 6. has been done. The upper wall 2a is closest to the heater 6 and is the part where oil droplets, food particles, etc. scattered from the food during heating are most likely to get stuck.
The above-mentioned coating layer 7 is formed on the wall a, and similar coating layers may be formed on other wall surfaces as necessary.
Further, the temperature inside the heating chamber 2 can be detected by a temperature detector 8.

FIG. 3 shows details of the front panel 5, which is composed of a dry firing instruction display section 9 and a keyboard 10. Such a keyboard 10 has 0 to 9
It has numeric keys and various function keys for time, temperature, empty combustion, start, and clear.

FIG. 4 shows the circuit of the cooking device, and the cooking device is controlled by a microcomputer 11.
That is, key signals from the keyboard 10 are input to the microcomputer 11, and the temperature detected by the temperature sensor 8 is input via the analog-to-digital converter 12. Based on these inputs, the microcomputer 11 controls the output of the heating signal H and also controls the output of the display signal D. When the heating signal H is output, the switching circuit 13 is turned on, and power from the commercial power supply 14 is applied to the heater 6 to heat the heater. When the display signal D is output, the dry firing instruction display section 9 lights up. The microcomputer 11 also performs other appropriate controls. The microcomputer 11 also includes an air-frying flag K, an air-frying display flag KD, a total counter TCNT that counts a predetermined 1-level signal (details will be described later) when the cooker is in use, a first time limit counter LCNT1, and a second time limit counter LCNT1. It has a built-in time counter LCNT2, etc.

FIG. 5 shows a flowchart of the program of the microcomputer 11, and the operation of the cooking device will be explained below with reference to this diagram.

When the cooker is turned on, the program first reaches step S1. In this step, the microcomputer 11 is initialized. The program then cycles through steps S2, S3, and S4. In the S2 step, the above keyboard 10
A key operation is detected, and in step S3, if the dry firing display flag KD is set, the output of the display signal D is started and the dry firing instruction display section 9 lights up. At the moment, the air firing display flag above is
KD is not set, so the dry firing instruction display section 9 does not light up. In step S4, it is determined whether or not the start key has been operated based on the detection in step S2. In this case, no such operation is performed, and therefore, as mentioned above, the program is set to S2, S3, and S4.
Cycle through steps.

Then, on the keyboard 10, the heating time and heating temperature (heating room temperature) for performing the desired heating are input.
To set the temperature, use the number keys, time keys, and temperature keys as appropriate. Then, such operation is detected in step S2, and the heating time and heating temperature are input and set to the microcomputer 11. Then, when you operate the start key on the keyboard 10, the program will start at S2, S3, and S4.
The cycle of steps is exited at step S4 and reaches step S5. In this step, it is determined whether the dry firing flag K is set. In this case it is not set, so the program then goes through step S6. In this step, the above keyboard 1
Heating is started based on the heating time and heating temperature input and set at 0. That is, the output of the heating signal H is controlled until the set heating time elapses so that the temperature inside the heating chamber 2 detected by the temperature sensor 8 is maintained at the set heating temperature. begins to be In the following step S7-1, the heating temperature set above (heating room temperature) is
is the activation temperature KTEMP of the coating layer 7 (approximately 200°C)
It is determined whether or not the following is true. If it is determined in step S7-1 that the number is "less than or equal to", the program then proceeds to step S7-2. In this step, the first time limit counter LCNT1 starts operating and generates a predetermined 1 level signal corresponding to the cumulative total counter TCNT, for example, every second. On the other hand, if it is determined in the above step S7-1 that it is not less than or equal to the above, the program then proceeds to step S7-3. In this step, the second time limit counter
The LCNT2 starts operating and generates a predetermined 1 level signal corresponding to the cumulative counter TCNT, for example every 5 seconds. In the next step S7-4, the first time counter LCNT1 or the second time counter LCNT1 is
The cumulative counter TCNT starts counting the predetermined 1 level signal generated by LCNT2. Here, the generation cycle of the predetermined 1-level signal counted by the cumulative counter TCNT is changed based on the heating temperature (heating room temperature) set above, and the above S7 is used as a means for bringing about such a change. -1, S7-2, and S7-3 steps correspond. In addition, the above S6, S7-1, S7-2,
The operations related to steps S7-3 and S7-4 do not function at all when dry firing operation is set using the keyboard 10.

Now, assuming that the heating temperature set above is below the activation temperature KTEMP, the program will be
Through each step of S7-1, S7-2, and S7-4 in sequence,
As a result, the cumulative counter TCNT starts counting a predetermined 1-level signal generated every second.

The program then reaches step S8. In this step, it is determined whether the dry firing display flag KD is set. In this case, it is not set, and the program then reaches step S9. In this step, the contents of the cumulative counter TCNT are set to a first predetermined value a (corresponding to several average heatings,
It is determined whether or not a predetermined count value (predetermined count value) has been reached. In this case, it has not been reached, and the program then reaches step S10. In this step, it is determined whether the heating time set above has elapsed. In this case, it has not passed, so the program then returns to step S2, and then S2 to S6, S7-1, S7-2, S7-4, S8 to
Cycle through S10 steps. When the heating time has elapsed, the program exits this cycle at step S10 and goes through steps S11 and S12. In step S11, the output control of the heating signal H is stopped, heating of the food by the heater is completed, and time measurement by the cumulative counter TCNT is stopped. and,
The first and second time-limited counters LCNT1 and
The operation of LCNT2 is stopped and the contents of these counters are cleared. In step S12, the dry firing flag K, dry firing display flag KD and cumulative counter are displayed.
Initialization of the microcomputer 11 is performed except for TCNT. In this case, the previously detected key operation details are cleared. The program then returns to the S2 step and S2, S3,
It will cycle through S4 steps.

Now, when such heating is performed several times and a certain heating is being executed, that is, when the program is running from S2 to S6,
When the contents of the cumulative counter TCNT reach the first predetermined value a while cycling through steps S7-1, S7-2, S7-4, and S8 to S10, the program exits the cycle at step S9. Reaching step S13. Here, although the coating layer 7 formed on the upper wall 2a of the heating chamber 2 has a self-purifying function (catalytic action), it gradually becomes contaminated by oil droplets, food particles, etc. scattered from the food during heating. Therefore, unless a special dry firing operation is performed at this point to sufficiently decompose the dirt into water and carbon dioxide and remove it, the coating layer 7 will not be able to fully exhibit its catalytic action.

Then, in step S13 above, the dry firing display flag is
KD is set. In the following step S14, it is determined whether the contents of the cumulative counter TCNT have reached a second predetermined value b (larger than the first predetermined value a). In this case, this has not been reached, and the program then passes through steps S10 and S2 and reaches step S3, but in this case, the dry firing indication flag KD is set, so the dry firing instruction display section 9 lights up.
And the programs are S2-S6, S7-1, S7-2,
After going through steps S7-4 and S8, the process reaches step S15. In this step, it is determined whether or not the dry firing operation is keyed. In this case, normal food heating is being carried out with the heater and dry baking operation is not set, so the program then goes from step S9, through steps S13 and S14, to step S10, and then returns to step S2. Therefore, the programs are S2 to S6, S7-1, S7-2, S7-4, S8, S15,
Desired heating is performed by cycling through steps S9, S13, S14, and S10. During this time, the dry firing instruction display section 9 continues to light up. When the desired heating time has elapsed, the program passes through steps S11 and S12, and then cycles through steps S2, S3, and S4, as described above. During this time, the display section 9 continues to be lit.

Based on this lighting, it is recognized that dry baking operation should be performed next, and the dry baking key and start key are sequentially operated on the keyboard 10 without putting food into the heating chamber 2. . Then, the program breaks out of the cycle of S2, S3, and S4 steps and goes to S5,
After passing through steps S6, S7-1, S7-2, S7-4, S8, and S15, the process reaches step S16. In this step, dry firing is started by continuously generating heat from the heater 6 for a predetermined period of time long enough to sufficiently decompose dirt adhering to the coating layer 7 into water and carbon dioxide and remove it. be done. In the following step S17, it is determined whether the predetermined time has elapsed. In this case, no time has elapsed, so the program then returns to step S2, and then steps S2 to S6, S7-1, S7-2, and so on.
Cycle through steps S7-4, S8, and S15 to S17. Thereafter, when the predetermined dry firing time has elapsed, the program exits this cycle at step S17 and returns to step S1, and the dry firing operation ends. The program then cycles through steps S2, S3, and S4. in this case,
The dry firing instruction display section 9 is of course turned off since it is after the S1 step.

By the way, in a situation where the dry baking instruction display section 9 is lit during the circulation of the S2, S3, and S4 steps described above, it is possible to perform a key operation to continue heating the food with the heater without performing the dry baking operation. In this case, the display section 9 will continue to light up, but S2 to S6, S7
-1, S7-2, S7-4, S8, S15, S9, S13,
The heater heating is performed in a cycle of steps S14 and S10. In this way, heater heating can be performed several times thereafter. Thus, the content of the cumulative counter TCNT reaches the second predetermined value b during a certain heating operation. Then the program starts from S2~
S6, S7-1, S7-2, S7-4, S8, S15, S9,
The cycle of steps S13, S14, and S10 is terminated at step S14 and reaches step S18. In this step, the dry firing flag K is set. The program then returns from step S10 to step S2 and then
Heater heating continues by cycling through steps S5, S15, S9, S13, S14, S18, and S10. When the desired heating time has elapsed, the program cycles through steps S11 and S12, then steps S2, S3, and S4, and ends the heater heating. Here, the second predetermined value b is
This means the point at which the food should no longer be heated with the heater, that is, the point at which the stains attached to the coating layer 7 should no longer become severe.

Therefore, if you perform a key operation to further heat the food with the heater, the program will change from S2 to S5, S15, S9, S13, S14, S18, S10.
It only cycles through the steps and does not pass through step S6 at all, so the heater heating described above cannot be performed.
Incidentally, if the key operations are then repeated and the dry firing key and start key are sequentially operated as described above, the dry firing operation is performed as described above. After that,
Heater heating can be performed.

As can be seen from the above explanation, the set heating temperature (heating room temperature) is the activation temperature of the coating layer 7.
Based on whether it is less than or equal to KTEMP, the generation period of the predetermined 1-level signal counted by the cumulative counter TCNT is 1 second (according to the operation of the first time limit counter LCNT1 in step S7-2) or 5 seconds.
seconds (S7-3 step second time counter LCNT
2).

Here, the degree of contamination of the heating chamber 2, that is, the degree of contamination of the coating layer 7 formed in the heating chamber 2, is as follows.
It changes based on the temperature inside the heating chamber 2 during heating.
More specifically, if the temperature in the heating chamber 2 is below the activation temperature KTEMP of the coating layer 7, the coating layer 7 will have a significantly poor ability to decompose adhered dirt into water and carbon dioxide, Therefore, the degree of contamination of the coating layer 7 is large. Conversely, when the temperature in the heating chamber 2 is higher than the activation temperature KTEMP of the coating layer 7, the coating layer 7 has an increased ability to decompose adhered dirt into water and carbon dioxide, and therefore the coating layer 7 The degree of contamination is small.

Therefore, if the degree of contamination is high, it is necessary to bring the dry firing point forward; on the other hand, if the degree of contamination is small, the dry firing point may be delayed. The generation period of the predetermined 1-level signal counted by the cumulative counter TCNT, which has a ) has increased to 5 seconds.

Under such control, the above cumulative counter
The count value of TCNT closely matches the degree of contamination of the coating layer 7, and therefore the cumulative count value
The time when the count value of TCNT reaches the first predetermined value a is the exact time when dry firing should be performed. Then, by giving a dry firing operation instruction at such a point, an accurate dry firing operation corresponding to the coating layer 7 can be performed.

In addition, in this embodiment, the above cumulative counter
Although the generation period of the predetermined 1-level signal counted by the TCNT is changed below the above-mentioned activation temperature KTEMP, it may also be changed below the activation temperature KTEMP by providing another temperature.

Further, in this embodiment, a cooking device that performs heating with a heater is described, but it is of course possible to use a cooking device that can also perform microwave heating, for example, in addition to heating with a heater.

(G) Effects of the Invention According to the present invention, the count value of the counter reaches a predetermined value in a state where the heating chamber in which the self-purifying coating layer is formed on the wall surface becomes dirty to some extent while being affected by the heating chamber temperature. When the value is reached, the dry firing instruction section gives a dry firing operation instruction, so the dry firing operation can be executed accurately.
Therefore, oil droplets, food particles, etc. adhering to the coating layer can be sufficiently decomposed and removed. Furthermore, it is possible to eliminate the need for a conventional dirt sensor, thereby reducing costs.

[Brief explanation of drawings]

The drawings show a cooking appliance according to an embodiment of the present invention, in which Fig. 1 is an external perspective view, Fig. 2 is a sectional view, Fig. 3 is a front view of main parts, Fig. 4 is a circuit diagram, and Fig. 5 is a diagram of a microcomputer. This is a flowchart of the program. 2...Heating chamber, 6...Heater, 7...Self-cleaning coating layer, 9...Dry firing instruction display section.

Claims (1)

[Claims] 1. A heating chamber in which a self-cleaning coating layer is formed on the wall and food is stored; a heating energy generating means for applying heating energy to the food in the heating chamber; a counter that counts a predetermined signal when the cooking device is used; It is characterized by comprising a changing means for changing the generation period of the signal based on the temperature in the heating chamber, and a dry firing instruction section that gives an instruction to perform dry firing operation when the count value of the counter reaches a predetermined value. Cooking device.