JPH10270162A - High frequency heating equipment - Google Patents

Abstract

(57) [Summary] [Problem] To automatically and accurately detect the presence or absence of an object to be heated housed in a heating chamber, the completion of thawing, and the completion of warming cooking, and to execute appropriate thawing and warming of the heated object. Obtain a possible high-frequency heating device. A temperature measuring means for measuring a temperature of a magnetron, a temperature change calculating means for calculating, for example, a temperature change per unit time (second) from the temperature measured by the temperature measuring means, First control means 5 for controlling the output of the power supply unit 6 based on the output obtained from the quantity calculation means 4, and a blower 40 for forcibly cooling the magnetron 31
And a power supply port 41 arranged at a predetermined position on the side wall of the heating chamber 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency heating apparatus provided with control means for automatically and accurately detecting the presence or absence of an object to be heated housed in a heating chamber, completion of thawing, and completion of warming cooking, and controlling driving of a magnetron. It concerns the device.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a block diagram of a high-frequency heating device provided with a function of detecting the completion of thawing disclosed in Japanese Patent Laid-Open Publication No. H10-209,004. In FIG. 13, 1
Is a heating chamber for accommodating the object to be heated 2, and 30 is a magnetron 3
A waveguide 32 for guiding the high frequency generated from 1 into the heating chamber 1;
Is a high-frequency absorbing member provided on the inner wall surface of the heating chamber 1, 33 is a temperature measuring unit that is in contact with the high-frequency absorbing member 32 to measure the temperature of the high-frequency absorbing member 32, and 34 is based on an output from the temperature measuring unit 33. Control means for controlling the output of the magnetron 31.

Here, the operation of the high-frequency heating apparatus provided with the function of detecting the completion of thawing will be described. In FIG.
The high frequency generated from the magnetron 31 is guided into the heating chamber 1 by the waveguide 30, and irradiates the frozen object to be heated 2 and the high frequency absorber 32 accommodated in the heating chamber 1. When the high frequency is applied to the high frequency absorber 32, the temperature of the high frequency absorber 32 increases with the irradiation time. Next, when the heated object 2 reaches a moderately thawed state, the high-frequency absorption efficiency of the heated object 2 increases,
Inevitably, the amount of high frequency applied to the high frequency absorber 32 is reduced. For this reason, the amount of temperature rise of the high-frequency absorber 32 per unit time is reduced, and the amount of temperature rise is always measured by the temperature measuring means 33. When the output from the temperature measurement unit 33 reaches a predetermined amount, the control unit 34 determines that the thawing of the object to be heated 2 is completed, and
Stop output of

Further, for example, a high-frequency heating apparatus provided with a function of detecting the completion of warming cooking disclosed in Japanese Patent Application Laid-Open No. 53-77365 discloses a method of measuring the amount of change in humidity in a heating chamber by measuring the humidity change in an exhaust hole provided in an exhaust hole of the heating apparatus. This is a method of detecting by a sensor and automatically detecting completion of warm cooking of the article to be heated 2 based on an output from the humidity sensor.

Further, for example, a high-frequency heating apparatus provided with a function of detecting the completion of thawing disclosed in Japanese Patent Application Laid-Open No. 3-219589 discloses an antenna which measures the amount of leaked radio waves in a heating chamber, that is, the amount of radio waves not absorbed by an object to be heated. This is a method of detecting and automatically detecting completion of thawing of the object to be heated 2 based on the output from the antenna.

Further, as a generally known example, a weight change amount of an object to be heated placed on a turntable is detected by a weight sensor, and the presence / absence of the object to be heated and completion of thawing are automatically determined based on an output from the weight sensor. There is also a detection method.

[0007]

In the conventional high-frequency heating apparatus, in the case of Japanese Patent Application Laid-Open No. 6-50546, a high-frequency absorbing material is provided on the inner wall surface of the heating chamber as described above, so The volume is reduced. For this reason, the space for accommodating the object to be heated is inevitably narrow, so that there is a problem that the size or shape of the object to be heated is limited. In addition, since steam, oil mist, and slag generated from the object to be heated adhere to the surface of the high frequency absorber, the high frequency absorption efficiency of the high frequency absorber is significantly reduced. For this reason, the amount of temperature rise per unit time of the high-frequency absorber decreases with the period of use of the heating device, so that there is a problem that the detection accuracy of the completion of thawing is significantly reduced.

In the case of Japanese Patent Application Laid-Open No. 53-77365, the humidity sensor itself deteriorates with time due to the adhesion of water vapor, oil mist, and slag generated from an object to be heated to the surface of the humidity sensor. For this reason, there has been a problem that the accuracy of detecting the completion of warming cooking significantly decreases with the use period of the heating device.

In the case of Japanese Patent Application Laid-Open No. Hei 3-219589, since the antenna is disposed in the heating chamber, the effective volume in the heating chamber is reduced in the same manner as described above. There was a point. further,
Water vapor, oil mist, and slag generated from the object to be heated adhere to the surface of the antenna, so that the high frequency detection sensitivity of the antenna is reduced. For this reason, there is a problem that the detection accuracy of the completion of defrosting is significantly reduced.

The method of detecting the presence or absence of an object to be heated and the completion of thawing using a weight sensor, which is a generally known example, is relatively low in the detection accuracy of the weight sensor itself. However, there is a problem that the detection accuracy of the completion of defrosting is poor.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and is affected by water vapor, oil mist, and slag generated from an object to be heated without reducing the effective volume in the heating chamber. It is an object of the present invention to provide a high-frequency heating device capable of accurately and automatically detecting the presence or absence of an object to be heated, the completion of thawing, and the completion of warming cooking, and performing appropriate cooking.

[0012]

According to a first aspect of the present invention, there is provided a high-frequency heating apparatus including a driving unit for driving a magnetron and a control unit for controlling the driving unit. Is provided, and a temperature change amount calculating means for calculating a temperature change amount per unit time from the temperature measured by the temperature measuring means is provided, and the temperature change amount calculated by the temperature change amount calculating means is provided. A comparison means for comparing a threshold value is provided, and the driving means is controlled based on a result from the comparison means.

A high-frequency heating apparatus according to a second aspect of the present invention compares the temperature change amount from the temperature change amount calculation means with the first threshold value immediately after the magnetron drive time elapses a predetermined time. A comparing means is provided, and when the first comparing means determines that the temperature change amount exceeds the first threshold value, the driving means is stopped.

The high frequency heating apparatus according to the third invention is characterized in that the temperature change amount from the temperature change amount calculation means and the second threshold value or the third threshold value immediately after the magnetron driving time has passed a predetermined time. Is provided, and after the temperature change amount exceeds the second threshold value or the third threshold value by the second comparison means, the temperature change amount decreases and the second The driving means is stopped when it is determined that the second threshold value or the third threshold value has been reached.

A high-frequency heating apparatus according to a fourth aspect of the present invention includes a weight detecting means for detecting the weight of an object to be heated housed in a heating chamber, and a second threshold value according to the weight detected by the weight detecting means. Alternatively, a threshold value correcting means for automatically correcting the third threshold value is provided.

According to a fifth aspect of the present invention, there is provided a high-frequency heating apparatus comprising: a driving unit for driving a magnetron; and a control unit for controlling the driving unit, wherein the control unit is provided between the magnetron and the driving unit. An inductive noise measuring means for measuring the inductive noise to be provided, a comparing means for comparing the inductive noise measured by the inductive noise measuring means with a certain threshold value, and controlling the driving means based on a result from the comparing means. It was made.

According to a sixth aspect of the present invention, there is provided the high-frequency heating apparatus, wherein the third comparing means compares the induction noise from the induction noise measuring means with the fourth threshold immediately after the magnetron has been driven for a predetermined time. And the driving means is stopped when the third comparing means determines that the induced noise has exceeded the fourth threshold value.

In the high-frequency heating apparatus according to the seventh invention, the induction noise from the induction noise measuring means and the fifth threshold value or the sixth threshold value are determined immediately after the magnetron has been driven for a predetermined time. A fourth comparing means for comparing is provided, and after the induced noise exceeds the fifth threshold value or the sixth threshold value by the fourth comparing means, the induced noise is reduced and a fifth threshold value is set. When it is determined that the value or the sixth threshold has been reached, the driving means is stopped.

The high-frequency heating apparatus according to the eighth invention is provided with a weight detecting means for detecting the weight of the object to be heated housed in the heating chamber, and a fifth threshold value according to the weight detected by the weight detecting means. Alternatively, a threshold value correcting means for automatically correcting the sixth threshold value is provided.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. 1 to 4 are views for explaining an embodiment of a high-frequency heating device according to the present invention. FIG. 1 is a block diagram showing a configuration of the high-frequency heating device, FIGS. 2 and 3 are examples of a temperature change pattern of the magnetron 31, and FIG. 4 is an operation flowchart showing a processing flow in the high-frequency heating device. In FIG. 1, the same reference numerals as those in the conventional example indicate the same or corresponding parts. 3 is a temperature measuring means for measuring the temperature of the magnetron 31; 4 is a temperature change calculating means for calculating, for example, a temperature change per unit time (second) from the temperature measured by the temperature measuring means 3; A first control means for controlling the output of the power supply unit 6 based on the output obtained from the means 4;
A blower for forcibly cooling the heating chamber 1 and a power supply port 41 disposed at a predetermined position on the side wall of the heating chamber 1.

FIG. 2 shows an example of a temperature change pattern of the magnetron 31 obtained by the temperature measuring means 3. In FIG. 2, when the object to be heated 2 is not accommodated in the heating chamber 1 (pattern A in FIG. 2), the temperature of the magnetron 31 rapidly rises from the start of driving of the magnetron 31, and thereafter, with the lapse of time. The temperature gradient is small, indicating a tendency of saturation. Next, when frozen food, for example, frozen tuna, is stored in the heating chamber 1 and thawed (pattern B in FIG. 2), the temperature of the magnetron 31 gradually increases from the start of driving of the magnetron 31 to a predetermined temperature. As time passes, the temperature gradient becomes smaller. Furthermore, when warm food, for example, milk is accommodated in the heating chamber 1 and heated and cooked (C pattern in FIG. 2), the temperature of the magnetron 31 rises very slowly from the start of driving the magnetron 31, After a lapse of a predetermined time, the temperature gradient becomes smaller. Note that the above-described temperature change pattern corresponds to the magnetron 3
Reference numeral 1 denotes a measurement pattern in a state where the fan 40 is forcibly cooled. This is the same for the second embodiment described later. As described above, it can be seen from the temperature pattern of FIG. 2 that the temperature of the magnetron 31 is: no load (no heated object 2)> frozen food> warmed food.

FIG. 3 shows an example of the temperature change pattern per unit time of the magnetron 31 obtained by the temperature change calculation means 4. In FIG. 3, when the object to be heated 2 is not accommodated in the heating chamber 1 (A pattern in FIG. 3),
The temperature change amount of the magnetron 31 rapidly increases after the start of the driving of the magnetron 31, rapidly decreases after exceeding the threshold value Hn, and passes through the threshold value Hn. Next, when, for example, frozen tuna is stored in the heating chamber 1 and thawed (B pattern in FIG. 3), the amount of temperature change of the magnetron 31 increases after the start of driving of the magnetron 31, and the threshold value Hr And gradually decreases after passing. Then, when the temperature change amount of the magnetron 31 reaches the threshold value Hr, that is, at the time point of the elapsed time Tr, the thawing of the frozen tuna is completed. Further, when, for example, milk is stored in the heating chamber 1 and warmed and cooked (pattern C in FIG. 3), the amount of change in temperature of the magnetron 31 gradually increases after the start of driving of the magnetron 31, and the threshold value is increased. It gradually decreases after exceeding Hm. Then, when the temperature change amount of the magnetron 31 reaches the threshold value Hm, that is, at the time point of the elapsed time Tm, the warming cooking of the milk is completed. From these temperature change patterns, the temperature change amount of the magnetron 31 exceeds the threshold value Hn at a point where a predetermined time has elapsed immediately after the start of driving of the magnetron 31, for example, the elapsed time Th, or the threshold values Hr and Hn By discriminating whether the heating object 1 or the heating object 2 is contained between the thresholds Hm and Hr, the presence or absence of the heating target 2 accommodated in the heating chamber 1 or the type of the heating target 2 is identified. can do.

Hereinafter, the operation of the high-frequency heating device according to the first embodiment will be described with reference to FIG. When the high-frequency heating device starts operating (step S0), power is supplied from the power supply unit 6 to the magnetron 31, and the temperature measurement unit 3 measures the temperature of the magnetron 31 (step S10). Next, the temperature change amount per unit time is calculated by the temperature change amount calculating means 4 from the temperature measured by the temperature measuring means 3 (step S20). Then, the controller 5 samples the temperature change H1 immediately after the elapsed time Th (see FIG. 3) (step S3).
0) Then, the magnitude of the temperature change amount H1 is compared with a preset threshold value Hn (step S40). Here, when the condition of H1 ≦ Hn is satisfied, the determination is YES, and when the condition is not satisfied, the determination is NO. When the determination is NO, it is determined that the heating chamber 1 has no load, that is, the heating chamber 1 does not contain the object 2 to be heated, and the operation of the high-frequency heating device is stopped (step S100).
Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

In the first control means 5, the elapsed time Th
The magnitude of the temperature change amount H1 immediately after and the threshold value Hn are compared (step S40), and when the condition of H1 ≦ Hn is satisfied, that is, when it is determined as YES, the object 2 to be heated is placed in the heating chamber 1. Judge that it is housed. Thereby, the control means 5 further compares the magnitude of the temperature change amount H1 with the threshold value Hr set in advance (step S50). Here, when the condition of H1 ≦ Hr is satisfied, the determination is YES, and when the condition is not satisfied, the determination is NO. If the determination is NO, it is determined that frozen food, for example, frozen tuna is contained in the heating chamber 1. Next, the temperature change amount H2 after the elapsed time Th is sampled (step S7).
0) Then, the magnitude of the temperature change amount H2 and the threshold value Hr are compared (step S70). Here, H2 ≦ Hr
If the condition is satisfied, the judgment is YES, and if not, the judgment is NO. If the determination is NO, the temperature change amount H2 after the elapsed time Th is sampled again (step S60), and thereafter, the same operation as described above is repeated. If the determination is YES, it is determined that the thawing of the frozen tuna has been completed, and the operation of the high-frequency heating device is stopped (step S100). Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

In the first control means 5, the temperature change amount H
1 and the threshold value Hr are compared (step S5).
0), if the condition of H1 ≦ Hr is satisfied, that is, if it is determined as YES, it is determined that the heating room 1 contains warm food such as milk. Next, the temperature change amount H2 after the elapsed time Th is sampled (step S80), and thereafter, the magnitude of the temperature change amount H2 is compared with a predetermined threshold value Hm (step S90). Here, H2
If the condition of .ltoreq.Hm is satisfied, the judgment is YES, and if not, the judgment is NO. If the determination is NO, the temperature change amount H2 after the elapsed time Th is sampled again (step S80), and thereafter, the same operation as described above is repeated. If the determination is YES, it is determined that the warm cooking of the milk has been completed, and the operation of the high-frequency heating device is stopped (step S100). Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

By employing the control algorithm having the above-described components, the presence / absence of the object to be heated 2 in the heating chamber 1 and the completion of thawing and completion of warming can be automatically and accurately detected. For this reason, when the article to be heated 2 is not stored in the heating chamber 1, it is possible to save electricity bills without wastefully operating the high-frequency heating device. Further, it is possible to obtain an effect that cooking of the article to be heated 2 can be appropriately performed and the running cost of the magnetron 31 at the time of cooking can be reduced.

Embodiment 2 FIG. FIG. 5 is a block diagram illustrating another embodiment of the high-frequency heating device according to the present invention. 5, the same reference numerals as those in the first embodiment denote the same or corresponding parts. Reference numeral 7 denotes a weight detecting means for detecting the weight of the article 2 to be heated accommodated in the heating chamber 1, and 8 automatically sets a threshold value preset in the first control means 5 according to the output from the weight detecting means 7. This is a threshold value correcting means of the temperature change amount to be corrected.

FIG. 6 shows a temperature change pattern per unit time of, for example, frozen tuna obtained by the temperature change amount calculating means 4. In FIG. 6, B1 indicates a temperature change pattern of 100 g of frozen tuna, B2 indicates a temperature change pattern of 200 g of frozen tuna, and B3 indicates a temperature change pattern of 300 g of frozen tuna. In the case of 100 g of frozen tuna, the amount of temperature change increases and the threshold value H
It gradually decreases after exceeding r1. And the threshold value H
The point in time at which r1 is reached is determined as the decompression completion time, and the elapsed time Tr1 at this point is the decompression completion time. Frozen tuna 2
In the case of 00 g, the amount of temperature change increases and the threshold value Hr2
It gradually decreases after exceeding. Then, the threshold value Hr2
Is determined as the thawing completion time, and the elapsed time Tr2 at this time is the thawing completion time. Furthermore, in the case of 300 g of frozen food, the amount of temperature change increases, and the threshold value Hr
It gradually decreases after exceeding 3. Then, the threshold value Hr
3 is determined to be the decompression completion time, and the elapsed time Tr3 at this point is the decompression completion time.

An operation flowchart showing the flow of the process of the high-frequency heating device in the second embodiment is the same as that in the first embodiment (see FIG. 4). Therefore, only a part of the processing flow will be described here. In FIG.
The first control means 5 controls the temperature change amount H2 and the threshold value Hr.
(Step S70), the temperature change threshold correction means 8 selects one of the thresholds Hr1, Hr2, Hr3, for example, according to the weight of the frozen tuna, and selects it. The threshold value preset in the first control means 5 is automatically corrected so that the threshold value is obtained. As a result, in the first control means 5, H2 ≦ Hr1, H2
A comparison determination of ≦ Hr2 or H2 ≦ Hr3 is performed, and detection of completion of defrosting is performed according to a predetermined operation flow. An operation flow for detecting the weight of the article to be heated 2 in the warm cooking and correcting the threshold value according to the weight to detect the completion of the warm cooking may be designed. Here, as a matter of course, it is important that the threshold value Hr of the frozen food and the threshold value Hm of the warmed food do not overlap each other and that Hr> Hm is always set.

By employing the control algorithm having the above-described components, it is possible to automatically and accurately detect the thawing completion or the heating cooking completion of the object 2 in the heating chamber 1. For this reason, cooking of the to-be-heated object 2 can be performed more appropriately, and the magnetron 31 at the time of cooking can be used.
This has the effect of reducing running costs.

Embodiment 3 7 to 10 are views for explaining still another embodiment of the high-frequency heating device according to the present invention. 7 is a block diagram showing the configuration of the high-frequency heating device. FIG. 8 is a diagram showing a voltage waveform between the power supply unit 6 and the magnetron 31. FIG. FIG. 10 is an example of a change pattern of induced noise that occurs, and FIG. 10 is an operation flowchart illustrating a flow of processing in the high-frequency heating device. 7, the same reference numerals as those in the first and second embodiments denote the same or corresponding parts. Reference numeral 9 denotes an induction noise measurement unit that measures induction noise generated between the power supply unit 6 and the magnetron 31;
Is a second control unit for controlling the output of the power supply unit 6 based on the output obtained from the induction noise measuring unit 9.

In FIG. 8, the induction noise generated between the power supply unit 6 and the magnetron 31 is
It can be seen that when 1 is intermittently driven by a voltage of half-wave rectification (a half cycle is 10 ms), it occurs immediately after driving (A in FIG. 8) and immediately after stopping (B in FIG. 8). Incidentally, the noise width is about 10 μs. The induction noise measuring means 9 is configured to always sample at least one of the induction noises generated immediately after the magnetron 31 is driven or stopped.
FIG. 9 is an example of an induced noise pattern obtained by the induced noise measuring means 9. In FIG. 9, when the heating target 2 is not accommodated in the heating chamber 1 (pattern A in FIG. 9), the absolute value of the induction noise sharply increases immediately after the start of the driving of the magnetron 31 and the threshold value Nn is increased. It has exceeded, and has been stably maintained at a predetermined level thereafter. Next, when frozen food, for example, frozen tuna is stored in the heating chamber 1 and thawed (B pattern in FIG. 9), the absolute value of the induced noise increases sharply immediately after the start of driving of the magnetron 31, It gradually decreases after exceeding the threshold value Nr. Then, the thawing of the frozen tuna is completed when the absolute value of the induction noise reaches the threshold value Nr, that is, when the elapsed time Tr. Further, when heating food, for example, milk, is stored in the heating chamber 1 and heated (pattern C in FIG. 9), the absolute value of the induced noise increases sharply immediately after the magnetron 31 starts to be driven. It gradually decreases after exceeding the threshold value Nm. Then, when the absolute value of the induction noise reaches the threshold value Nm, that is, at the time point of the elapsed time Tm, the warm cooking of the milk is completed. From these induction noise patterns, at the point where the induction noise has passed a predetermined time immediately after the start of driving of the magnetron 31, for example, at the point of the elapsed time Th, the threshold N
n to determine whether or not there is the object to be heated 2 housed in the heating chamber 1 by determining whether or not the temperature exceeds n, intervenes between the threshold values Nr and Nn, or intervenes between Nm and Nr. The type of the object to be heated 2 can be identified.

Hereinafter, a third embodiment will be described with reference to FIG.
The operation of the high-frequency heating device in the above will be described. When the high-frequency heating device starts operating (step S0), power is supplied from the power supply unit 6 to the magnetron 31, and the induction noise measuring means 9 measures induction noise generated between the power supply unit 6 and the magnetron 31 (step S0). Step S1
0). Next, the second control means 10 samples the induced noise N1 immediately after the elapsed time Th (see FIG. 9) (step S20), and thereafter, the induced noise N1 and the threshold value N are sampled.
Then, the size is compared with n (step S30). here,
If the condition of N1 ≦ Nn is satisfied, the judgment is YES, and if not, the judgment is NO. If the determination is NO, the heating chamber 1 is determined to be in a no-load state, that is, a state in which the object 2 to be heated is not accommodated in the heating chamber 1, and the operation of the high-frequency heating device is stopped (step S90). Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

In the second control means 10, the elapsed time T
The magnitude of the induction noise N1 immediately after h is compared with the threshold value Nn (step S30), and when the condition of N1 ≦ Nn is satisfied, that is, when it is determined as YES, the object to be heated 2 is placed in the heating chamber 1. Judge that it is housed. Thereby, the control means 10 further compares the magnitude of the induction noise N1 with the magnitude of the threshold value Nr (step S40). Here, N1 ≦
If the condition of Nr is satisfied, the judgment is YES, and if not, the judgment is NO. If the determination is NO, it is determined that frozen food, for example, frozen tuna is contained in the heating chamber 1. Next, the induced noise N2 after the elapsed time Th is sampled (step S50), and thereafter, the magnitude of the induced noise N2 is compared with the threshold value Nr (step S60). Here, when the condition of N2 ≦ Nr is satisfied, the determination is YES, and when the condition is not satisfied, the determination is NO. If the determination is NO, the elapsed time T is again set.
h is sampled (step S).
50) Thereafter, the same operation as described above is repeated. If the determination is YES, it is determined that the thawing of the frozen tuna is completed, and the operation of the high-frequency heating device is stopped (step S90). Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

The second control means 10 compares the magnitude of the induction noise N1 with the magnitude of the threshold value Nr (step S4).
0), when the condition of N1 ≦ Nr is satisfied, that is, YES
Is determined, it is determined that the heating room 1 contains warm food such as milk. Next, the induced noise N2 after the elapsed time Th is sampled (step S7).
0) Then, the magnitude of the induction noise N2 is compared with the threshold Nm (step S80). Here, N2 ≦ Nm
If the condition is satisfied, the judgment is YES, and if not, the judgment is NO. If the determination is NO, the induction noise N2 after the elapsed time Th is sampled again (step S70), and thereafter, the same operation as described above is repeated. If the determination is YES, it is determined that the warming cooking of the milk has been completed, and the operation of the high-frequency heating device is stopped (step S90). Thereby, the power supplied from the power supply unit 6 to the magnetron 31 is cut off.

Note that, in addition to the absolute value of the induced noise, the amount of change in the induced noise per unit time may be calculated, and the magnitude of the amount of change and a certain threshold value may be compared and determined. By such an operation flow, the presence or absence of the object to be heated 2 in the heating chamber 1
It is possible to detect completion of thawing and completion of warming cooking. This is the same in Embodiment 4 described later.

By employing the control algorithm having the above-described components, the presence / absence of the object to be heated 2 in the heating chamber 1, the completion of thawing, and the completion of heating cooking can be automatically and accurately detected. For this reason, when the article to be heated 2 is not stored in the heating chamber 1, it is possible to save electricity bills without wastefully operating the high-frequency heating device. Further, it is possible to obtain an effect that cooking of the article to be heated 2 can be appropriately performed and the running cost of the magnetron 31 at the time of cooking can be reduced.

Embodiment 4 FIG. FIG. 11 is a block diagram illustrating still another embodiment of the high-frequency heating device according to the present invention. In FIG. 11, the same reference numerals as those in the first to third embodiments indicate the same or corresponding parts. Reference numeral 11 denotes an induction noise threshold value correcting means for automatically correcting a threshold value preset in the second control means 10 according to the output from the weight detecting means 7.

FIG. 12 shows an induced noise pattern of, for example, frozen tuna obtained by the induced noise measuring means 9. In FIG. 12, B1 in the figure denotes frozen tuna 100
g and B2 are frozen tuna 200 g, B3 is frozen tuna 30
It is an induction noise pattern of 0 g. 100g frozen tuna
In the case of, the induction noise sharply increases and the threshold value Nr1
It gradually decreases after exceeding. Then, the threshold value Nr1
Is determined as the thawing completion time, and the elapsed time Tr1 at this time is the thawing completion time. Frozen tuna 200
In the case of g, the induction noise increases sharply and the threshold value Nr
It gradually decreases after exceeding 2. Then, the threshold value Nr
2 is determined as the thawing completion time, and the elapsed time Tr2 at this time is the thawing completion time. Furthermore, in the case of 300 g of frozen food, the induced noise increases rapidly and gradually decreases after exceeding the threshold value Nr3. Then, the point in time when the threshold value Nr3 is reached is determined as the decompression completion time, and the elapsed time Tr3 at this point is the decompression completion time.

The operation flow chart showing the flow of the processing of the high-frequency heating device in the fourth embodiment is the same as that in the third embodiment (see FIG. 10). Therefore, only a part of the processing flow will be described here. In FIG. 10, when the magnitude of the induction noise N2 is compared with the threshold value Nr by the second control means 10 (step S6).
0), the threshold value correcting means 11 for the induction noise, for example, threshold values Nr1, Nr2, Nr according to the weight of the frozen tuna.
3 is selected, and the threshold value preset in the second control means 10 is automatically corrected so as to reach the selected threshold value. As a result, the second control means 10
A comparison determination of 2 ≦ Nr1, N2 ≦ Nr2 or N2 ≦ Nr3 is performed, and detection of the completion of decompression is performed according to a predetermined operation flow. An operation flow for detecting the weight of the article to be heated 2 in the warm cooking and correcting the threshold value according to the weight to detect the completion of the warm cooking may be designed. Here, as a matter of course, it is important that the threshold value Nr of the frozen food and the threshold value Nm of the warmed food do not overlap each other and that Nr> Nm is always set.

By employing the control algorithm having the above-described constituent means, the completion of the thawing or the completion of the warm cooking of the object to be heated 2 in the heating chamber 1 can be automatically and accurately detected. For this reason, cooking of the to-be-heated object 2 can be performed more appropriately, and the magnetron 31 at the time of cooking can be used.
This has the effect of reducing running costs.

[0042]

Since the present invention is configured as described above, it has the following effects.

According to a first aspect of the present invention, there is provided a high-frequency heating apparatus comprising: a driving unit for driving a magnetron; and a control unit for controlling the driving unit. The control unit includes a temperature measuring unit for measuring a temperature of the magnetron. Is established,
A temperature change amount calculating unit that calculates a temperature change amount per unit time from the temperature measured by the temperature measuring unit; and a comparing unit that compares the temperature change amount calculated by the temperature change amount calculating unit with a certain threshold value. Since the drive means is controlled based on the result from the comparison means, the completion of thawing and the completion of warm cooking of the object to be heated housed in the heating chamber can be automatically and accurately detected. For this reason, a high-frequency heating device that can appropriately cook the object to be heated and that can reduce the running cost of the magnetron during cooking can be obtained.

The high-frequency heating device according to the second aspect of the present invention compares the temperature change amount from the temperature change amount calculation means with the first threshold value immediately after the magnetron driving time has passed a predetermined time. The comparison means is provided, and the driving means is stopped when the first comparison means determines that the temperature change amount exceeds the first threshold value. Can be automatically and accurately detected. For this reason, a high-frequency heating device capable of preventing deterioration due to no-load operation of the magnetron can be obtained.

The high-frequency heating apparatus according to the third invention is characterized in that the temperature change amount from the temperature change amount calculating means and the second threshold value or the third threshold value immediately after the magnetron driving time elapses a predetermined time. Is provided, and after the temperature change amount exceeds the second threshold value or the third threshold value by the second comparison means, the temperature change amount decreases and the second The drive means is stopped when it is determined that the second threshold value or the third threshold value has been reached, so that the completion of thawing of the object to be heated contained in the heating chamber and the completion of warming cooking are automatically determined. Can be detected with high accuracy. For this reason, the high-frequency heating apparatus which can reduce the running cost of the magnetron at the time of cooking and can appropriately cook the object to be heated is obtained.

The high-frequency heating apparatus according to the fourth invention is provided with a weight detecting means for detecting the weight of the object to be heated housed in the heating chamber, and a second threshold value according to the weight detected by the weight detecting means. Alternatively, a threshold value correcting means for automatically correcting the third threshold value is provided, so that even if the weight of the object to be heated accommodated in the heating chamber changes every time, the thawing is completed and the heating is completed automatically. Can be detected well. For this reason, the high-frequency heating apparatus which can reduce the running cost of the magnetron at the time of cooking and can appropriately cook the object to be heated is obtained.

According to a fifth aspect of the present invention, there is provided a high-frequency heating apparatus including a driving unit for driving a magnetron, and a control unit for controlling the driving unit, wherein the control unit generates a signal between the magnetron and the driving unit. An inductive noise measuring means for measuring the inductive noise to be provided, a comparing means for comparing the inductive noise measured by the inductive noise measuring means with a certain threshold value, and controlling the driving means based on a result from the comparing means. Therefore, the completion of thawing and the completion of warm cooking of the object to be heated housed in the heating chamber can be automatically and accurately detected. For this reason, a high-frequency heating device that can appropriately cook the object to be heated and that can reduce the running cost of the magnetron during cooking can be obtained.

The high-frequency heating apparatus according to the sixth invention is characterized in that the third comparing means compares the induction noise from the induction noise measuring means with the fourth threshold immediately after the magnetron driving time has passed a predetermined time. And the driving means is stopped when the third comparing means determines that the induction noise has exceeded the fourth threshold value, so that the presence or absence of the object to be heated housed in the heating chamber is automatically determined. Can be accurately detected. For this reason, a high-frequency heating device capable of preventing deterioration due to no-load operation of the magnetron can be obtained.

The high-frequency heating apparatus according to the seventh aspect of the present invention is configured such that the induction noise from the induction noise measuring means and the fifth threshold value or the sixth threshold value are determined immediately after the magnetron driving time has passed a predetermined time. A fourth comparing means for comparing is provided, and after the induced noise exceeds the fifth threshold value or the sixth threshold value by the fourth comparing means, the induced noise is reduced and a fifth threshold value is set. The drive means is stopped when it is determined that the value or the sixth threshold value has been reached, so that the completion of thawing and the completion of warm cooking of the object to be heated accommodated in the heating chamber can be automatically and accurately detected. . For this reason, the high-frequency heating apparatus which can reduce the running cost of the magnetron at the time of cooking and can appropriately cook the object to be heated is obtained.

The high-frequency heating apparatus according to the eighth invention is provided with weight detecting means for detecting the weight of the object to be heated housed in the heating chamber, and a fifth threshold value according to the weight detected by the weight detecting means. Alternatively, a threshold value correcting means for automatically correcting the sixth threshold value is provided, so that even when the weight of the object to be heated accommodated in the heating chamber changes every time, the thawing is completed and the heating is completed automatically. Can be detected well. For this reason, the high-frequency heating apparatus which can reduce the running cost of the magnetron at the time of cooking and can appropriately cook the object to be heated is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating Embodiment 1 of a high-frequency heating device according to the present invention.

FIG. 2 is an example of a temperature change pattern according to the first embodiment.

FIG. 3 is an example of a temperature change amount pattern per unit time according to the first embodiment;

FIG. 4 is a flowchart illustrating the operation of the first embodiment.

FIG. 5 is a block diagram illustrating Embodiment 2;

FIG. 6 is an example of a temperature change amount pattern per unit time according to the second embodiment.

FIG. 7 is a block diagram illustrating a third embodiment.

FIG. 8 is an example of a voltage waveform according to the third embodiment.

FIG. 9 is an example of an induced noise change pattern according to the third embodiment.

FIG. 10 is a flowchart illustrating the operation of the third embodiment.

FIG. 11 is a block diagram illustrating Embodiment 4;

FIG. 12 is an example of an induced noise change pattern according to the fourth embodiment.

FIG. 13 is a block diagram illustrating a conventional high-frequency heating device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heating chamber, 2 Heated object, 3 Temperature measuring means, 4 Temperature change amount calculating means, 5 First control means, 6 Power supply section, 7
Weight detecting means, 8 temperature change amount threshold value correcting means,
9 Induction noise measurement means, 10 second control means, 11
Induction noise threshold correction means, 31 magnetron, 32 high frequency absorber, 33 temperature detector, 40 blower, 41 power supply port.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Toshiro Akiyama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Within Mitsubishi Electric Co., Ltd. (72) Inventor Tetsuya Miyama 1728-1 Koeda, Hanazono-cho, Osato-gun, Saitama Mitsubishi Electric Home Equipment Co., Ltd.

Claims (8)

[Claims] 1. A heating chamber for accommodating an object to be heated, a magnetron for sending a high frequency to the heating chamber via a power supply port,
In a high-frequency heating apparatus including a driving unit that drives the magnetron and a control unit that controls the driving unit, the control unit includes a temperature measurement unit that measures a temperature of the magnetron, and a temperature measured by the temperature measurement unit. And a comparison means for comparing the temperature change amount calculated by the temperature change amount calculation means with a certain threshold value. A high-frequency heating device wherein the driving means is controlled based on a result. 2. The first comparing means for comparing the temperature change amount from the temperature change amount calculating means with a first threshold immediately after a predetermined time period of the magnetron drive time has elapsed. 2. The apparatus according to claim 1, wherein the driving means is stopped when it is determined by the first comparing means that the amount of temperature change exceeds a first threshold value. High frequency heating device. 3. The controller according to claim 1, wherein the controller determines the temperature change amount from the temperature change amount calculator and a second threshold value or a third threshold value immediately after a predetermined time has elapsed. A second comparing means for comparing is provided.
After the temperature change amount exceeds the second threshold value or the third threshold value by the comparing means, the temperature change amount decreases to reach the second threshold value or the third threshold value. 2. The high-frequency heating apparatus according to claim 1, wherein the drive unit is stopped when it is determined that the vehicle has arrived. 4. The control means comprises: a weight detecting means for detecting a weight of an object to be heated housed in the heating chamber; and the second threshold value or the third threshold value in accordance with the weight detected by the weight detecting means. 4. A high-frequency heating apparatus according to claim 3, further comprising a threshold value correcting means for automatically correcting the threshold value. 5. A heating chamber for accommodating an object to be heated, a magnetron for sending a high frequency to the heating chamber via a power supply port,
In a high-frequency heating apparatus including a driving unit for driving the magnetron and a control unit for controlling the driving unit, the control unit measures an induction noise generated between the magnetron and the driving unit. And a comparing means for comparing the induced noise measured by the induced noise measuring means with a certain threshold value, wherein the driving means is controlled based on a result from the comparing means. High frequency heating device. 6. The control means includes third comparison means for comparing the induction noise from the induction noise measurement means with a fourth threshold immediately after the magnetron driving time has passed a predetermined time. 6. The high-frequency heating apparatus according to claim 5, wherein when the third comparing means determines that the induction noise exceeds a fourth threshold value, the driving means is stopped. . 7. The control means compares the induction noise from the induction noise measurement means with a fifth threshold value or a sixth threshold value immediately after a drive time of the magnetron elapses a predetermined time. Fourth comparing means is provided.
After the induction noise exceeds the fifth threshold value or the sixth threshold value by the comparing means, the induction noise decreases and reaches the fifth threshold value or the sixth threshold value. 6. The high-frequency heating apparatus according to claim 5, wherein the driving means is stopped when it is determined that the high-frequency heating is performed. 8. The control means includes a weight detecting means for detecting a weight of an object to be heated housed in the heating chamber, and the fifth threshold value or the sixth threshold value according to the weight detected by the weight detecting means. 8. A high-frequency heating apparatus according to claim 7, further comprising threshold value correcting means for automatically correcting the threshold value.