JPS6135673B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a high-frequency heating device, and improves the life performance of a high-frequency oscillation source by adjusting the timing of adding high-frequency heating to oven heating. Figure 1 shows the state of the combined operation of the high-frequency oscillation source and the heat source such as an electric heater in a recent high-frequency heating device, and the elapsed time of the temperature in the heating chamber.The heating temperature is set to _T1 and the time _t1 is shown. This is a case where the food is heated during the heating period, and the portion indicated by H indicates the time when the heat generating source is operating, which is the time when so-called oven heating is performed. The portion indicated by R indicates the operating time of the high frequency oscillation source, which is the time when so-called high frequency heating is being performed. Among these, oven heating is performed by maintaining the temperature inside the heating chamber where the food is stored at a set value _T1 .
This method gradually heats the food from the surface layer, browning the surface of the food and creating the so-called oven-like taste. However, since it takes a long time to heat the inside of the food, high-frequency heating is added intermittently to heat the inside of the food at the same time. However, such oven heating requires a process of raising the temperature in the heating chamber to a _set temperature, that is, preheating. is being reported. Simultaneously with the completion of this preheating, the high frequency oscillation source is controlled to start a predetermined operation as shown in FIG. Therefore, when the user opens and closes the door for taking food in and out of the heating chamber and puts the food into the heating chamber, the food is kept at the temperature T ₁ for the set time t ₁ and also with high-frequency heating as described above. heating is performed. However, since the time required for this preheating is relatively long at 10 to 15 minutes, the user is often doing other work during this time, and conversely, even if the aforementioned buzzer etc. is used to notify the end of preheating, It is not always the case that the food is put into the heating chamber immediately, but it may be left as is for a while, for example, until point Z shown in FIG. During this standing time, that is, between Y and Z, the high frequency oscillation source performs the prescribed operation as described above even though there is no food in the heating chamber. The no-load operation not only shortens the service life of the heating chamber, but also increases the electric field strength within the heating chamber, which has the disadvantage that sparks are likely to occur within the heating chamber. The present invention was made in view of the above circumstances, and
The purpose is to provide a high-frequency heating device that improves the timing of starting a combined operation by adding high-frequency heating to oven heating and improves the life performance of the high-frequency oscillation source. The present invention is equipped with a mechanism that detects the opening and closing of the door of the heating chamber, and when it is detected that the door has been opened and closed after the temperature inside the heating chamber reaches near the set temperature, high-frequency heating is added and the combined operation is started. In this way, the above purpose can be achieved. An embodiment of the present invention will be explained below with reference to the drawings. Figure 2 explains the timing at which the high frequency oscillation source and the heat generating source start combined operation in the high frequency heating device of the present invention, Figure 3 is a perspective view of the main part of the high frequency heating device of the present invention, and Figure 4 is Similarly, FIG. 5 is a block diagram of the main part of the control circuit, and is a diagram explaining the operation of the RAM section. In these figures, 1 is a microcomputer (hereinafter referred to as a microcomputer), which is connected to a ROM unit 1-1 via a CPU (central information processing unit) 1-1.
2 and RAM sections 1-3 are connected. Digital value variable devices 2 and 3 are connected between the output terminal E and the input terminal B and between the output terminal E and the input terminal C of the microcomputer 1, and when they are operated, the ROM section 1-2 of the microcomputer 1 due to the function of
The heating time t and the heating temperature are respectively stored in parts B and C of the RAM part 1-3. In addition, a time pulse generation circuit 4 is connected to the input terminal 5 of the microcomputer 1, and when the conditions after the start of heating listed in Table 1, which will be described later, are satisfied, the ROM section 1-2 operates to generate a time pulse generator. A reference signal is generated for subtracting the time t stored in the section B or other time as necessary. Furthermore, between the input terminal a and the output terminal c of the microcomputer 1, there is a function switch group 5-1 for selecting each heating function, including a high-frequency heating switch 5-a, a high-frequency oven heating switch 5-b, etc., which have already been set. Each switch including a cancellation switch 5-2 for canceling the contents that have been made and a heating start switch 5-3 are connected in a matrix. Note that the function switch group 5
When a specific function is selected from 1-1 and this button is pressed, this function is stored in section A of the RAM section 1-3 by the function of the ROM section. Also, when pressing other switch buttons, make sure to
It is stored in the ROM section 1-2. On the other hand, a high-frequency oscillation source 8, for example, a magnetron, is installed in the heating chamber 7 to radiate microwaves into the heating chamber, and a heat generating source 9, for example, is an electric heater, which is installed in the heating chamber and heats the inside of the same chamber. The former is the driving power supply 10
Via an electronic switch device 11-1 consisting of an AC control element and a driver circuit, the latter is connected to an AC power supply 12 via an electronic switch device 11-2. Furthermore, a door 6 for taking food in and out of the heating chamber 7 is attached to the opening of the heating chamber 7, and a door 6 is attached to the support part of this door in conjunction with opening and closing of the door.
A door switch 13 that turns on and off is installed. Further, the output terminals A and B of the microcomputer 1 are connected to the electronic switch devices 11-1 and 11-, respectively.
The driver terminal d of 2 is connected, and the ROM part 1-
2 and according to the logic shown in Table 1, these electronic switch devices are turned on when these output terminals go to a high level, that is, "H" state. Furthermore, an analog-to-digital conversion circuit 14 is connected between the output terminal d and the input terminal d of the microcomputer 1, and this includes the heating chamber 7.
A temperature detection element 15 is attached to and connected to the temperature detection element 15 for detecting the temperature T ₀ in the same room. In addition, the above
The analog value of the detected temperature is converted into a digital value via the conversion circuit 14 by the function of the ROM section 1-2, and then is stored in the D of the RAM section 1-3.
stored in the section. Furthermore, the door switch 13 is connected to the input terminal e of the microcomputer 1, and when this switch is opened or closed once after heating starts, this state is memorized and the E part of the RAM changes logically from 0 to 1. It's getting old. Also mentioned above
The F section of the RAM section is designed to logically change from 0 to 1 when the temperature _T0 in the heating chamber becomes higher than the set temperature T, as shown in Table 1, which will be described later. Further, the output terminal A of the microcomputer 1 is output only when the logical product of the E part and F part becomes 1 due to the action of the ROM part 1-2. It is designed to be in the "H" state. Also, ROM section 1 of microcomputer 1
-2 includes the following 1st part, including the content already explained.
It has the function of performing the controls listed in the table. Note that in Table 1, the value of ΔT is a small value of, for example, about 1 to 2° C., and is stored in the ROM section 1-2.

[Table] *Only during a separately configured predetermined time
It becomes H.
Next, the operation of the present invention in such a configuration will be explained. First, select and press the high frequency oven heating switch 5-ro button from the function switch group 5-1.
Next, the knob of the digital value variable device 2 is turned to set a predetermined heating time _t1 , and then the knob of the digital value variable device 3 is turned to set a predetermined heating temperature _T1 . Therefore, by the action of the ROM section 1-2, this function is stored in the A section of the RAM 1-3, the time value _t1 is stored in the B section, and the temperature value _T1 is stored in the C section, as described above. Therefore, when the heating start switch 5-3 button is pressed, the microcomputer 1 immediately starts measuring the digital value T ₀ of the temperature inside the heating chamber via the temperature detection element 15 and the conversion device 14 as described above. ,
From now on, this change will be successively measured and RAM section 1-3 will be measured.
I will re-memorize it in part D. However, since the heating chamber has not yet been warmed up, when comparing the values stored in the C section and the D section, it is found that T ₁ -ΔT>T ₀ , so the state is in the state 1 in Table 1. Therefore, only the output terminal port is in the "H" state, and the heat generating source 9 is connected to the AC power source 12 as described above, and preheating in the heating chamber is started. When the temperature in the heating chamber eventually rises to T ₁ -ΔT=T ₀ , the preheating is finished, although the explanation will be omitted, and this is notified by, for example, sounding a buzzer or the like. However, as mentioned above, there are cases where the user is unable to immediately put food into the heating chamber 7 while continuing to do other work. In this case, the temperature in the heating chamber continues to rise and becomes T ₁ > T ₀ > T ₁ −△T. Moreover, since the door 6 is still being opened and closed, the state shown in Table 1 3 is reached, and the state of the output terminal remains the same and does not change.
Eventually, the temperature inside the heating chamber rises further and T ₀ > T ₁
However, even at this time, if the door 6 is not opened or closed and food is not put into the heating chamber, the state will be 5 in Table 1, and the output terminal port will be in the "L" state. Therefore, contrary to the case described above, the operation of the heat source 9 is stopped, and heating by the heat source is stopped. After that, when the temperature inside the heating chamber decreases due to heat radiation, etc., the state becomes T ₁ > T ₀ > T ₁ −△T, that is, the state 3 in Table 1, and the heat source starts operating, and there are no particular changes from then on. If not, states 3 and 5 are repeated to maintain the temperature in the heating chamber near the set value _T1 . However, when the user puts food into the heating chamber by opening and closing the door 6 of the heating chamber 7, the door switch 13 experiences an OFF state more than once, so the E section of the RAM section 1-3 becomes becomes 1. Therefore, from Table 1, if the state at that time is 3, then 4
If it is 5, it changes to 6. Therefore, from the same table, the value of time _t1 stored in the section B is started to be subtracted based on the pulse supplied from the time pulse generation circuit 4 as described above, and as shown in FIG. Measurement is performed at time t ₁ shown in FIG. Furthermore, from this point forward, states 4 and 6 are alternately repeated in response to changes in the temperature T ₀ in the heating chamber, as in the case described above, and the heat generating source 9 performs intermittent operation, but especially in the case of state 6, the output terminal is in the "H" state only during a period based on a predetermined control content configured separately, so the electronic switch device 11-1 is in the ON state only during this period, and AC current is supplied to the AC power source 10 to the drive power source 10. 12 are connected. Therefore, the high frequency oscillation source 8 operates to radiate microwaves into the heating chamber 7. However, at this time, since there is food in the heating chamber 7, no-load operation is performed. Eventually, as time passes, the value stored in section B mentioned above becomes 0.
When this happens, the state shown in Table 1 is reached, and from this point on, both output terminals A and B become "L". Therefore, all heating operations are stopped and heating is completed, and this is notified by, for example, a buzzer or the like, although the explanation will be omitted. As explained above, according to the present invention, when the temperature inside the heating chamber reaches the vicinity of the set temperature and the door of the heating chamber is opened and closed after heating starts, high-frequency heating is added to oven heating to perform a combined operation. A high frequency heating device capable of performing the following is obtained. Therefore, there is no risk of shortening the life of the high frequency oscillation source by operating the high frequency oscillation source when there is no food in the heating chamber. Further, there are advantages such as the power source strength in the heating chamber is increased and there is less risk of sparks occurring within the heating chamber.

[Brief explanation of the drawing]

Figure 1 shows the state of the combined operation of the high frequency oscillation source and the oscillation source in a recent high frequency heating device and the temperature over time in the heating chamber, Figure 2 shows the start time of the combined operation in the high frequency heating device of the present invention, and Figure 3 4 is a block diagram of the main part of the control circuit, and FIG. 5 is a diagram illustrating the operation of the RAM section. Explanation of symbols, 1: Microcomputer, 1-
3: Same RAM section, 6: Opening/closing door, 7: Heating chamber, 8:
High frequency oscillation source, 9: Heat source, 13: Door switch.

Claims (1)

[Claims] 1 A heating chamber, a high-frequency oscillation source for radiating microwaves into this heating chamber, a heat generation source for heating the inside of this heating chamber, an opening/closing door for taking food in and out of this heating chamber, and a door for opening and closing this door. In a device equipped with an open/close detection mechanism for detecting an open/close state and a temperature setting function for setting the temperature inside the heating chamber, after the temperature inside the heating chamber reaches near the set temperature due to the heat generation source. Moreover, when the detection mechanism detects the opening and closing of the door after the start of heating, the high frequency oscillation source is operated based on predetermined control, and both are used in combination to perform heating.