JP5347954B2 - Cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker capable of lowering or stopping heating output and ensuring safety by accurately determining that a user starts heating without putting food on a heating pan by mistake. <P>SOLUTION: In this heating cooker, heating is performed by loading the heating pan 7 on which a high frequency heating element 19 is attached, in a heating chamber 2 and generating high frequency by a high frequency generating means 3, a surface temperature of the heating pan is detected by an infrared ray sensor 13, a food detecting section 16 determines the presence or absence of food on the heating pan on the basis of the detected temperature, and the output of the high frequency generating means is lowered or stopped to ensure safety when the absence of food is determined. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a heating cooker that heats and cooks food on a heating dish by heating the heating dish with high frequency.

  A microwave oven, which is a typical high-frequency heating cooker, is highly functionalized by adding functions such as an oven, grill, and steam to it. As a new function, it has a heating pan with a high-frequency heating element that absorbs high-frequency and generates heat, and the food placed on the heating pan is heated by the heater and the bottom is heated by the heat of the heating pan. Some foods, such as grilled fish, can be cooked to burn.

  There is also an example in which heating control is performed by detecting the surface temperature of such a heating pan. It heats the food without placing it on the heating pan, raises it to a certain temperature, then places the food on the heating pan and heats it at high frequency to burn the surface in contact with the heating pan. After that, there is a method in which the high frequency is stopped and the surface that is not in contact with the heating pan by the heater is burnt (see Patent Document 1).

JP 2003-217818 A

  However, if the user forgets to place food by mistake and heats only with the heating pan, the heating pan becomes too hot, and the high-frequency heating element attached to the heating pan becomes hot. It may be dangerous, for example, if it becomes too much, it may peel off.

  The present invention has been made to solve the above problems, and when a user accidentally heats food without placing it on the heating pan, it correctly determines that and outputs the heating. The purpose is to ensure safety.

Cooker of the invention, a high-frequency onset generating means, a heating pan pasted the high-frequency heating element which generates heat by receiving a high frequency of the high frequency generating means, a heating chamber for mounting the heating pan, the heating Temperature distribution detection means for detecting the temperature of the surface of the dish at a plurality of locations, and heating control means for controlling the high-frequency generation means, wherein the heating control means detects the temperature of the heating dish based on the temperature distribution detected by the temperature distribution detection means . A food detection unit that determines the presence or absence of the food on the food, and the food detection unit includes a minimum temperature extraction unit that extracts a minimum temperature from temperature detection points within a predetermined range detected by the temperature distribution detection unit; , configuration wherein the determining the presence or absence of food on the heating pan by lowest temperature to extract the lowest temperature extraction unit, when it is detected that the food is not by the food detector to reduce or stop the output of the high frequency generating means It is.

With this configuration, the heating pan with the high-frequency heating element attached is mounted in a heating chamber, and the high-frequency generating means generates high frequency and heats it, and the temperature distribution detecting means detects the temperature at multiple locations, of which the temperature of the heating dish The rising portion is set as a predetermined temperature detection range, and when the temperature rise of the minimum temperature in the predetermined range is large, it is determined that there is no food on the heating pan. In this case, it ’s the way the food is placed.
If it is determined that there is no food on the heating pan, the output of the high-frequency generating means is reduced or stopped to ensure safety.

  In this case, variations in how food is placed can be absorbed, and it can be determined more reliably that there is no food on the heating pan. When it is determined that there is no food, the output of the high-frequency generator is reduced or stopped to ensure safety. To do.

The heating cooker of the present invention, a high frequency generation unit, a heating pan pasted the high-frequency heating element which generates heat by receiving a high frequency of the high frequency generating means, a heating chamber for mounting the heating pan, the heating A plurality of plate-hanging portions having temperature distribution detecting means for detecting a plurality of temperatures on the surface of the dish and heating control means for controlling the high-frequency generating means, wherein the heating cabinet can set a height for mounting the heating dish; And the heating control means extracts a minimum temperature from each of a plurality of different predetermined temperature detection points detected by the temperature distribution detection means, and the minimum temperature extraction part extracts the minimum temperature. A maximum temperature extraction unit for extracting the maximum temperature from the minimum temperature, and a food detection unit for determining the presence or absence of food on the heating dish based on the maximum temperature extracted by the maximum temperature extraction unit, the food detection unit No food When it detects the door is configured to reduce or stop the output of the high frequency generating means.

  With this configuration, the heating pan with the high-frequency heating element attached is mounted in a heating chamber, the high-frequency generating means generates a high frequency to heat, the temperature distribution detecting means detects the surface temperature distribution of the heating dish, and the heating dish is The temperature rise of the heating pan at each of the multiple heights to be mounted is defined as a predetermined range, and there are multiple minimum temperature extraction sections that extract the minimum temperature of each predetermined range, and the maximum temperature is the highest among the multiple minimum temperatures. Since the temperature extraction unit extracts, if there is no food on it, it can be determined that there is no food because there is no food on it, and there is no food. Sometimes, the output of the high frequency generating means is reduced or stopped to ensure safety.

  According to the present invention, when the user forgets to put the heating dish by mistake and heats it up, it can be judged correctly and the output of heating can be reduced or stopped to ensure safety.

The block diagram of the heating cooker in Embodiment 1 of this invention Top view of the heating pan in the same embodiment A-A 'sectional view of FIG. Explanatory drawing of the visual field of the infrared sensor in the heating chamber in the same embodiment Flowchart explaining the flow of operation in the same embodiment The block diagram of the heating cooker in Embodiment 2 of this invention Flowchart explaining the flow of operation in the same embodiment The block diagram of the heating cooker in Embodiment 3 of this invention The block diagram of the infrared sensor of the heating cooker in the embodiment Explanatory drawing of the infrared temperature detection spot in the bottom of the heating chamber in the same embodiment Explanatory drawing of the infrared temperature detection spot in the heating pan surface in the same embodiment Flowchart explaining the flow of operation in the same embodiment The block diagram of the heating cooker in Embodiment 4 of this invention Explanatory drawing of the infrared temperature detection spot on the surface of a heating plate when a heating plate is mounted on the lower stage in the same embodiment Flowchart explaining the flow of operation in the same embodiment

A first invention is a high frequency onset generating means, a heating pan pasted the high-frequency heating element which generates heat by receiving a high frequency of the high frequency generating means, a heating chamber for mounting the heating pan, the heating pan surface Temperature distribution detecting means for detecting a plurality of temperatures and heating control means for controlling the high frequency generating means, and the heating control means is provided on the heating pan by the temperature distribution detected by the temperature distribution detecting means . A food detection unit for determining the presence or absence of food, the food detection unit has a minimum temperature extraction unit for extracting a minimum temperature from the temperature detection locations of the predetermined range detected by the temperature distribution detection unit, It determines the presence of food on the heating pan by lowest temperature to extract the lowest temperature extraction unit, when it is detected that the food is not by the food detector is an arrangement to reduce or stop the output of the high frequency generating means With this configuration, by mounting the heating pan pasted high frequency heating element heating chamber and heated by generating a high frequency at a high frequency generating means detects the temperature at a plurality of locations at a temperature distribution detecting unit, the temperature of which heating pan The rising portion is set as a predetermined temperature detection range, and when the temperature rise of the minimum temperature in the predetermined range is large, it is determined that there is no food on the heating pan. In this case, variations in how food is placed can be absorbed, and it can be determined more reliably that there is no food on the heating pan . When it is determined that there is no food, the output of the high-frequency generator is reduced or stopped to ensure safety. To do.

A second invention is a high frequency onset generating means, a heating pan pasted the high-frequency heating element which generates heat by receiving a high frequency of the high frequency generating means, a heating chamber for mounting the heating pan, the heating pan surface A temperature distribution detecting means for detecting a plurality of temperatures and a heating control means for controlling the high-frequency generating means, and the heating cabinet has a plurality of dish hanging portions capable of setting a height for mounting the heating dish. The heating control means includes a minimum temperature extraction unit for extracting a minimum temperature from a plurality of temperature detection points in a plurality of different predetermined ranges detected by the temperature distribution detection unit, and a minimum temperature extracted by the minimum temperature extraction unit. A maximum temperature extraction unit for extracting the maximum temperature from the food, and a food detection unit for determining the presence or absence of food on the heating dish based on the maximum temperature extracted by the maximum temperature extraction unit, and the food detection unit Detected that there is no The can is configured to reduce or stop the output of the high frequency generating means.

  With this configuration, the heating pan with the high-frequency heating element attached is mounted in a heating chamber, the high-frequency generating means generates a high frequency to heat, the temperature distribution detecting means detects the surface temperature distribution of the heating dish, and the heating dish is The temperature rise of the heating pan at each of the multiple heights to be mounted is defined as a predetermined range, and there are multiple minimum temperature extraction sections that extract the minimum temperature of each predetermined range, and the maximum temperature is the highest among the multiple minimum temperatures. Since the temperature extraction unit extracts, if there is no food on it, it can be determined that there is no food because there is no food on it, and there is no food. Sometimes, the output of the high frequency generating means is reduced or stopped to ensure safety.

(Embodiment 1)
FIG. 1 shows a configuration diagram of a heating cooker according to the first embodiment of the present invention. In FIG. 1, a heating cooker 1 is used as a microwave oven capable of high-frequency heating and heating by hot air and heat radiation for cooking food.

  A magnetron 3 which is a high frequency generating means for outputting high frequency in a heating chamber 2 for storing food, a flat heater 4 for generating radiant heat, a convection heater (seeds heater) 5 for sending warm air into the heating chamber 2 and circulation. Fan 6, heating pan 7 used when food is placed and heated, and pan hook 8 for mounting heating pan 7 are provided, and at least one of high frequency, radiation, and hot air is supplied to heating chamber 2. Then, the food in the heating chamber 2 is heated.

The heating chamber 2 is formed inside a box-shaped main body case 9 that is open on the front surface, and an opening / closing door 10 that opens and closes the food outlet of the heating chamber 2 is provided on the front surface of the main body case 8. Further, a thermistor 11 for detecting the ambient temperature in the heating chamber 2 is provided at the upper corner of the heating chamber 2 so that the tip of the thermistor 11 protrudes into the heating chamber 2, and the wall surface of the heating chamber 2 is provided outside the heating chamber 2. An infrared sensor 13 is provided so as to face the inside of the heating chamber 2 from the peep hole 12 provided in the window. The infrared sensor 13 detects the surface temperature of food in the heating chamber 2.

  The magnetron 3 is disposed in a space below the heating chamber 2, and a stirrer blade 14 is provided at a position for receiving a high frequency generated from the magnetron 3. And by rotating the stirrer blade | wing 14, it is made to supply in the heating chamber 2 stirring a high frequency. The magnetron 3 and the stirrer blade 14 can be provided not only on the lower side of the heating chamber 2 but also on the upper surface and side surfaces.

  The heating control means 15 is based on the atmosphere temperature in the heating chamber 2 detected by the thermistor 11, the surface temperature of the food in the heating chamber 2 detected by the infrared sensor 13, etc., the magnetron 3, the flat heater 4, and the convection heater 5. Control etc. The heating control means 15 includes a food detection unit 16, and the food detection unit 16 includes a timer 17 that counts the time since the heating by the magnetron 3 is started. Based on the temperature detected by the sensor 13, it is determined whether or not food is placed on the heating pan 7 during the heating menu using the heating pan 7.

  Next, the heating pan 7 will be described with reference to FIGS. 2 is a top view of the heating pan 7, and FIG. 3 is a cross-sectional view taken along the line A-A 'in FIG. The heating dish 7 is a metal plate 18 that serves as a food mounting surface, a high-frequency heating element 19 that is made of ferrite as a main material that is bonded to the metal plate 18, and a portion that is gripped by the user. It has a handle portion 20 made of a resin material to be hung on the dish-mounting portion 8 on the wall surface.

  The metal plate 18 has a depth that allows water to be accumulated with wavy irregularities on the surface. By forming irregularities with the metal plate 18 as a waveform, the bonding area of the high-frequency heating element 19 is increased, and the amount of heat generated on the high-frequency heating element 19 is increased. The surface of the metal plate 18 is subjected to fluorine coating having a high antifouling effect, and the back surface is subjected to black heat resistant coating having a high heat absorption effect.

  Further, the heating pan 7 is provided with a slit hole 21. The high frequency generated from the magnetron 3 and introduced into the heating chamber 2 is mostly absorbed by the high frequency heating element 19, but part of the high frequency passes through the slit hole 21 and goes above the heating pan 7 and directly on the heating pan 7. Heat the food.

  Next, the visual field of the infrared sensor 13 in the heating chamber 2 will be described with reference to FIG. FIG. 4A is a diagram for explaining the visual field of the infrared sensor 13 when a food 22 such as fish is placed on the heating pan 7 and heated, and the spread of the visual field is indicated by a dotted line. The infrared sensor 13 detects the temperature in the heating chamber 2 from the peephole 12 provided on the upper side surface of the heating chamber 2. When the heating pan 7 is attached, the high-frequency heating element 19 is bonded to the back surface. A part of the metal plate 18 is viewed. Depending on how the food 22 is placed, a part of the food 22 becomes the field of view.

  Here, when high frequency heating is performed by the magnetron 3 when no food is placed on the heating pan 7, the high frequency heating element 19 bonded to the metal plate 18 absorbs the high frequency, and the metal plate 18 rapidly The temperature rises.

  However, when the food 22 is placed, the temperature rise of the food 22 is suppressed, and the temperature rise of the metal plate 18 is moderate. The difference can be detected by the infrared sensor 13. Further, when the food 22 is in the field of view of the infrared sensor 13, the temperature to be detected further increases gradually, and it is possible to determine whether or not the food 22 is placed on the heating dish 7. .

  FIG. 4B is a diagram illustrating the field of view of the infrared sensor 13 when the heating pan 7 is not attached. The infrared sensor 13 is attached obliquely so as to face the inside of the heating chamber 2 from the peephole 12 so that the end of the bottom surface on the opposite side to which the infrared sensor 13 is attached is the field of view on the bottom surface of the heating chamber 2. Yes.

  When high frequency heating is performed by the magnetron 3 in an empty state where the heating pan 7 is not mounted, the high frequency supplied into the heating chamber 2 is not absorbed, and the temperature of the bottom surface of the heating chamber 2 is rapidly increased. Here, when the heating dish 7 is not present, the bottom surface of the heating chamber 2 is set as the field of view, and when the heating dish 7 is not attached, the food 22 is not placed on the heating dish 7. The temperature rise will be detected in the same way.

  Thus, if a high temperature is detected by the temperature detected by the infrared sensor 13 when the magnetron 3 is heated at a high frequency, the food dish 22 is not used on the heating pan 7. It can be distinguished as a correct state in which the dish 7 is present and the food 22 is placed, and the food detection unit 16 of the heating control means 15 performs the determination.

  And the state where it is misused without the heating pan 7 performs the same determination as the case where it is misused without the food 22 being placed.

  The operation | movement at the time of heating using the heating pan 7 is demonstrated using the flowchart of FIG. When cooking the grilled food, the user first puts food such as fish on the heating dish 7 and attaches it to the dish hanging portion 8 of the heating chamber 2, and closes the open / close door 10. Then, a grilled food menu such as grilled fish is selected by an operation unit (not shown), and a heating start operation is performed.

  First, the heating control means 15 drives the magnetron 3 in S <b> 1 to start high-frequency heating in the heating chamber 2. In S2, the temperature T is detected by the infrared sensor 13. In step S3, the temperature T detected by the food detection unit 16 is compared with a predetermined temperature Ts.

  Here, if the temperature is lower than the predetermined temperature Ts, the process proceeds to S6, and if it is higher, the process proceeds to S4 and the magnetron is stopped. This is because the high temperature is detected, that is, it is determined that no food is placed on the heating pan 7, and the magnetron 3 is stopped for safety.

  Then, in S5, it is displayed that no food is placed or a buzzer is sounded to notify the user, and the process is terminated.

  In S6, it is determined whether or not the elapsed time from the start of the high frequency heating by the magnetron 3 counted by the timer 17 has passed the predetermined time t1, and if it has already elapsed, the process proceeds to S7, but if it has not yet elapsed. Returning to S2, the detection of the temperature T is repeated, and the comparison with the predetermined temperature Ts is repeated in S3.

  When the heating dish 7 is mounted without placing the food 22 and high frequency heating is performed by the magnetron 3, for example, the surface temperature rises to 100 ° C. or more after 1 minute. On the other hand, when the food 22 is placed on the heating pan 7 and subjected to high frequency heating, the surface temperature of the heating pan 7 after 1 minute is only about 60 ° C.

  Therefore, for example, if the predetermined time t1 is set to 1 minute and the predetermined temperature Ts is set to 70 ° C., when the food 22 is not placed, the process proceeds to S4 within 1 minute to stop the magnetron 3 and the food 22 is placed. If so, the process proceeds to S7 after one minute has passed. If the heating pan 7 is not attached, the temperature of the bottom surface of the heating chamber 2 rises to about 80 ° C. in one minute, so the process proceeds to S4 and the magnetron 3 is stopped.

  Then, the high frequency continues to be generated until a predetermined heating time t2 elapses in S7. When heating is performed for a predetermined time t2, the driving of the magnetron 3 is stopped in S8, and the process proceeds to S9. The predetermined time t2 varies depending on the food, but it is about 5 to 10 minutes. The salmon fillet is easy to be burnt, so it is a short time, and the sesame is a long time because it is difficult to burn.

  In S <b> 9, the flat heater 4 is energized to radiately heat the food on the heating dish 7 from above to burn the surface of the food 22. The flat heater 4 is continuously energized until a predetermined heating time t3 has elapsed in S10. When heating is performed for a predetermined time t3, the energization of the flat heater is stopped in S11 and the cooking is finished. Here, the predetermined time t3 varies depending on the food, but it is approximately the same as t2 and is approximately 5 to 10 minutes.

  As described above, in the present embodiment, the temperature rise characteristic of the surface of the heating dish 7 when the food 22 is placed on the heating dish 7 and mounted in the heating chamber 2 to generate a high frequency, and heating is performed. It is determined whether or not the food 22 is placed from the difference in temperature rise characteristics of the surface of the heating pan 7 when the food 22 is not placed on the plate 7. If the food 22 is not placed, the high frequency is determined. Can be stopped to ensure safety.

  In the present embodiment, since the field of view of the infrared sensor 13 is the bottom surface of the heating chamber 2 when the heating pan 7 is not mounted, food is loaded even when the heating pan 7 is not mounted. Since the temperature rise is the same as when not placed, high frequency can be stopped and safety can be ensured.

(Embodiment 2)
FIG. 6 shows a block diagram of a heating cooker in the second embodiment of the present invention. In FIG. 6, parts having the same functions as those of the first embodiment described above are denoted by the same reference numerals and description thereof is omitted.

  The difference from the first embodiment is that the food detection unit 16 of the heating control unit 15 includes an initial temperature storage unit 23 and a temperature difference calculation unit 24.

  In the second embodiment, the temperature detected by the infrared sensor 13 at the start of high frequency generation by the magnetron 3 is stored in the initial temperature storage unit 23. Thereafter, the temperature difference calculation unit 24 continues to calculate the temperature difference between the temperature detected by the infrared sensor 13 and the temperature stored in the initial temperature storage unit 23.

  Then, the timer 17 counts the time from the start of heating by the magnetron 3, and the elapsed time from the start of heating and the temperature difference calculated by the temperature difference calculation unit 24, that is, from the initial temperature detected by the infrared sensor 13. Based on the increased value, it is determined whether or not food is placed on the heating pan 7.

  The operation will be described with reference to the flowchart of FIG. In FIG. 7, the same processes as those in FIG.

  When the user puts food such as fish on the heating pan 7 and attaches it to the pan hook 8 of the heating chamber 2 and closes the open / close door 9 and starts the heating operation, the initial temperature is first detected by the infrared sensor 13 in S21. T0 is detected, and the detected temperature is stored in the initial temperature storage unit 23. And magnetron 3 is driven by S1, a high frequency is generated in heating cabinet 2, and heating is started.

Next, the temperature T is detected by the infrared sensor 13 in S2. Further, in S22, the temperature difference calculation unit 2
4 calculates a temperature difference ΔT between the temperature T detected by 4 and the initial temperature T 0 stored in the initial temperature storage unit 23.

  In S23, it is compared whether or not the calculated temperature difference ΔT is smaller than a predetermined temperature difference ΔTs. If smaller, the process proceeds to S6. If larger, it is determined that the food 22 is not placed on the heating pan 7. In S4, the magnetron 3 is stopped, and in S5, the user is notified and the process is terminated.

  In S6, it is determined whether or not a predetermined time period t1 has elapsed since the start of heating by the magnetron 3 by the timer 16, and if it has not yet elapsed, the process returns to S2 and repeats the above processing, while the predetermined time period t1 is set. If it has elapsed, the process proceeds to S7. The operations after S7 are the same as those in the first embodiment shown in FIG.

  Here, when high-frequency heating is performed by the magnetron 3 without placing the food 22 on the heating chamber 7, for example, the surface temperature rises by 80 ° C. or more in one minute. On the other hand, when the food 22 is placed on the heating pan 7 and subjected to high-frequency heating, the temperature rises only by about 40 ° C.

  Therefore, for example, if the predetermined time t1 is set to 1 minute and the predetermined temperature difference ΔTs is set to 50 ° C., when the food 22 is not placed on the heating pan 7, the process proceeds to S4 within 1 minute and the magnetron 3 is turned on. If it stops and the foodstuff 22 is mounted on the heating pan 7, it will progress to S7 when 1 minute passed.

  Even when the heating pan 7 is not mounted, the temperature of the bottom surface of the heating chamber 2 rises by about 60 ° C. in one minute, so the process proceeds to S4 and the magnetron 3 is stopped.

  As described above, in the present embodiment, the temperature rise characteristic of the surface of the heating dish 7 when the food 22 is placed on the heating dish 7 and mounted in the heating chamber 2 to generate a high frequency, and heating is performed. It is determined whether or not the food 22 is placed from the difference in temperature rise characteristics of the surface of the heating pan 7 when the food 22 is not placed on the plate 7. If the food 22 is not placed, the high frequency is determined. Can be secured to ensure safety, and it is determined whether the food 22 is placed based on the temperature difference from the initial temperature at the start of heating. Thus, the presence / absence determination of the food 22 can be definitely performed even under different conditions of the initial temperature of the surface of the heating pan 7.

(Embodiment 3)
FIG. 8 shows a configuration diagram of a heating cooker according to the third embodiment of the present invention. In FIG. 8, parts having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. The difference from the first embodiment is that the infrared sensor 13 is a temperature distribution detecting means for detecting the temperature at a plurality of locations instead of the temperature at one location.

  The food detection unit 16 includes a minimum temperature extraction unit 25 that extracts a minimum temperature from a plurality of temperatures within a predetermined range in the temperature distribution detected by the infrared sensor 13. The food detection unit 16 determines that no food is placed on the heating pan 7 if the minimum temperature reaches a predetermined temperature or higher before the predetermined time elapses.

  The structure of the infrared sensor in this Embodiment is demonstrated using FIG. In FIG. 9, the infrared sensor 13 includes eight infrared detection elements 27 provided in a line on a substrate 26, a case 28 that accommodates the entire substrate 26, and the case 28 in which the infrared detection elements 27 are arranged. And a stepping motor 29 that moves in a direction perpendicular to the direction.

On the substrate 26, a metal can 30 enclosing the infrared detection element 27 and an electronic circuit 31 for processing the signal of the infrared detection element are provided. Further, the can 30 is provided with a lens 32 through which infrared rays pass. In addition, the case 28 is provided with an infrared passage hole 33 through which infrared light passes and a lead wire hole 34 through which a lead wire from the electronic circuit 31 passes.

  With this configuration, when the stepping motor 29 rotates, the case 28 can be moved in a direction perpendicular to the direction in which the infrared detection elements 27 are aligned.

  FIG. 10 is a diagram illustrating an infrared temperature detection spot on the bottom surface of the heating chamber 2. As shown in the figure, the heating cooker 1 according to the third embodiment can detect the temperature distribution in almost all regions in the heating chamber 2 by the reciprocating rotation of the stepping motor 29 of the infrared sensor 13. It can be done.

  Specifically, for example, first, the eight infrared detection elements 27 arranged in a line of the infrared sensor 13 simultaneously detect the temperature distribution in the region A1 to A8 in FIG. Next, when the stepping motor 29 rotates and the case 28 moves, the infrared detection element 27 detects the temperature distribution in the region B1 to B8.

  When the stepping motor 29 rotates and the case 28 moves, the infrared detector 27 detects the temperature distribution in the region C1 to C8, and similarly D1 to D8, E1 to E8, F1 to F8, G1 to G8. , H1 to H8 are sequentially detected.

  Further, following the above operation, the stepping motor 29 rotates in the reverse direction, so that G1 to G8, F1 to F8, E1 to E8, D1 to D8, C1 to C8, and B1 to B8 from the region side of H1 to H8. The temperature distribution is detected in the order of A1 to A8.

  The infrared sensor 13 can detect the entire temperature distribution in the heating chamber 2 by repeating the above operation.

  Here, in FIG. 10, there are a number of fields of view that protrude from the bottom surface of the heating chamber 2, and this means that part or all of the field of view includes the opening / closing door 10, the wall surface of the heating chamber 2, and the like. Depending on the ratio, the temperature at which both temperatures are averaged will be detected. Thus, the part which protrudes is made in order to detect the temperature of the heating pan 7 mentioned later.

  With this configuration, for example, when re-heating a chilled food, the heating control unit 15 drives the magnetron 3 to generate a high frequency in the heating chamber 2 to heat the food, and the infrared sensor 12 If the temperature distribution in the heating chamber 2 is detected, and if any part of A1 to H8 exceeds a predetermined temperature (for example, 70 ° C.), the heating is terminated, and the food is heated to an appropriate temperature no matter where it is placed. Can do.

  FIG. 11 is a diagram for explaining infrared detection spots on the surface of the heating dish 7 when the heating dish 7 is attached to the dish hanging portion 8 of the heating chamber 2.

  Since the heating pan 7 is mounted at a height sufficiently close to the infrared sensor 13, the entire infrared detection spot is a region indicated by V in FIG. 11, and a part thereof has a view of the handle portion 20 where the temperature hardly increases. . A portion of the metal plate 18 to which the high-frequency heating element 19 is bonded as a field of view is a region indicated by Vx surrounded by a dotted line.

Returning to FIG. 10, when the region Vx is represented by a detection spot on the bottom surface of the heating chamber 2, portions of A1 to A3, B1 to B3, C1 to C3,..., H1 to H3 (hereinafter referred to as A1 to H3). It is a region that occupies the portion corresponding to the left wall surface of the heating chamber 2 from the left end on the bottom surface of the heating chamber 2.

  Referring again to FIG. 11, when high-frequency heating is performed without placing food on the heating pan 7, the temperature of the metal plate 18 with the high-frequency heating element 19 bonded to the back surface rises, and the Vx region is temperature detected. All locations A1 to H3 rise in temperature. Among them, even if the minimum temperature extraction unit 25 extracts the minimum temperature, the high temperature is extracted.

  On the other hand, when food is placed on the heating pan 7, the region Vx has a large temperature distribution. When food is placed in this Vx region, when the food enters the field of view, the temperature of the detected portion is remarkably slow.

  As the surface temperature of the metal plate 18 is closer to food, the temperature rise is slower, and as the distance from the food is higher, the temperature rise is more rapid. There are places where food is left up to the user, and it is difficult to limit the food placement position, but there is a high possibility that there is a place where the temperature rises slowly somewhere in the Vx region, and detection of A1 to H3 If the lowest temperature is extracted from the places, there is a difference in temperature rise between when food is placed and when food is not placed, and the presence or absence can be determined.

  The operation of the third embodiment will be described using the flowchart of FIG. In FIG. 12, the same processes as those in FIG. When the user places food such as fish on the heating pan 7 and attaches it to the pan hook 8 of the heating chamber 2 and closes the open / close door 9 to start heating, the heating control means 15 first starts the magnetron 3 in S1. To start high-frequency heating in the heating chamber 2.

  In S31, the infrared sensor 13 detects the temperature distribution of A1 to H8. In S32, the food detection unit 16 extracts the minimum temperature Tmin of A1 to H3 among them. In S33, the minimum temperature Tmin is compared with a predetermined temperature Tmins. If the temperature is lower than the predetermined temperature Tmins, the process proceeds to S6, and if it is higher, the process proceeds to S4 and the magnetron 3 is stopped.

  This is because the high temperature is detected, that is, it is determined that no food is placed on the heating pan 7, and the magnetron 3 is stopped for safety. In S5, the user is informed that no food is placed, and the process is terminated.

  In S6, it is determined whether or not the elapsed time from the start of the high frequency heating by the magnetron 3 counted by the timer 17 has passed the predetermined time t1, and if it has already elapsed, the process proceeds to S7, but if it has not yet elapsed. Returning to S31, detection of the temperature distribution of A1 to H8, extraction of the lowest temperature of A1 to H3 in S32, and comparison of the minimum temperature Tmin and the predetermined temperature Tmins in S33 are repeated. The operations after S7 are the same as those in the first embodiment shown in FIG.

  Here, when the predetermined time t1 is, for example, 1 minute, when the heating pan 7 is mounted without placing food and high-frequency heating is performed by the magnetron 3, the entire surface rises to 100 ° C. or higher in the Vx region, and the minimum temperature It is 100 degreeC or more even if it extracts. On the other hand, when the food was placed on the heating pan 7 and subjected to high-frequency heating, the surface of the food remained almost the same as when the food was preserved even after 1 minute. Only to the extent.

  Even if food does not enter the field of view, the surface temperature of the heating pan 7 rises only to about 50 to 60 ° C. after 1 minute near the food, and becomes 60 ° C. or less if the minimum temperature in the Vx region. .

  Therefore, for example, if the predetermined time t1 is set to 1 minute and the predetermined temperature Tmins is set to 70 ° C., when the food is not placed, the process proceeds to S4 within 1 minute and the magnetron 3 is stopped, and the food is placed. When one minute has passed, the process proceeds to S7.

  In this way, if food is not placed on the heating pan, it is determined whether the food is placed at the place where the temperature rapidly rises at the lowest temperature of the entire detection location that is the field of view of the infrared sensor 13. Therefore, it is less affected by the food placement position, and the presence or absence of food can be determined.

  In the third embodiment, whether or not food is placed on the heating pan 7 is determined based on whether or not the minimum temperature of the temperature detection location in the predetermined range exceeds the predetermined temperature Tmins. As described in the second embodiment, the temperature detected in the initial stage is stored, the temperature difference between the detected temperature is calculated, and the food is placed depending on whether or not the temperature rise at the lowest temperature difference exceeds the predetermined temperature difference. It may be determined whether or not.

  In this case, the presence or absence of food can be more accurately determined without being affected by the atmospheric temperature or the temperature when repeatedly heated.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described with reference to FIG. The infrared sensor 13 in the fourth embodiment detects the temperature distribution as in the third embodiment, and has the configuration shown in FIG.

  The food detection unit 16 of the heating control unit 15 has a plurality of minimum temperature extraction units 25. The maximum temperature extraction unit 35 is configured to extract the maximum temperature from the minimum temperatures extracted by the plurality of minimum temperature extraction units 25.

  Further, there are a plurality of dish hanging portions 8 so that the heating dish 7 can be mounted at two kinds of heights, an upper stage and a lower stage. In general, it is easier to burn food when it is closer to the flat heater 4 and it is often heated in the upper stage. However, if the height of the food is high, such as roast chicken, it may not be put in the upper stage. The lower stage is prepared as another height.

  FIG. 14 is a diagram illustrating an infrared detection spot on the surface of the heating dish 7 when the heating dish 7 is attached to the lower plate hanging portion 8 of the heating chamber 2.

  The heating pan 7 is sufficiently separated from the infrared sensor 13 and close to the detection spot on the bottom surface of the heating chamber 2 shown in FIG. The entire infrared detection spot is a region indicated by a solid line V in FIG. 14, and a part of the infrared detection spot is a peripheral portion such as the slit hole 21 where the temperature does not rise so much, the wall surface of the heating chamber 2, and the door 10. A portion having a visual field of the metal plate 18 to which the high-frequency heating element 19 is bonded is a region indicated by a dotted line Vy.

  Returning to FIG. 10, when the region Vy is represented by a detection spot on the bottom surface of the heating chamber 2, it is a portion of C1 to C8, D1 to D8, E1 to E8, and F1 to F8 (hereinafter referred to as C1 to F8). Referring again to FIG. 14, when high-frequency heating is performed without placing food on the heating dish 7, the temperature of the metal plate 18 that adheres the high-frequency heating element 19 to the back surface rises, and the Vy region detects the temperature. All the locations C1 to F8 rise in temperature.

  The plurality of minimum temperature extraction units 25 extract the minimum temperature from the Vx region shown in FIG. 11 as a predetermined range, that is, the detected temperatures of A1 to H3, and the other is shown in FIG. The lowest temperature is extracted from the detected Vy region, that is, the detected temperatures of C1 to F8. The maximum temperature extraction unit 35 extracts the higher one of the minimum temperatures A1 to H3 and the minimum temperatures C1 to F8.

  When the heating pan 7 is mounted on the upper stage, if no food is placed when high-frequency heating is performed, the temperature of all the regions indicated by Vx in FIG. 11 rises rapidly, and all of A1 to H3 are at a high temperature. Also gets hot.

  On the other hand, as for C1 to F8, the temperature of C8 to F8 and the like with the handle portion 20 as the field of view does not rise, so the minimum temperature is low. The maximum temperature extraction unit 35 extracts the lowest temperature of A1 to H3 to extract a high temperature.

  On the other hand, when food is placed, A1 to H3 contain a low temperature portion, so the minimum temperature is low, and C1 to F8 similarly includes the handle portion 20 in the field of view, so the minimum temperature is low. Even if the highest temperature extraction unit 35 extracts the higher temperature in the low temperature, it is low temperature.

  When the heating pan 7 is mounted on the lower stage, if no food is placed when high-frequency heating is performed, the temperature of all the regions indicated by Vy shown in FIG. 14 rises rapidly, and all of C1 to F8 become high temperature. Therefore, the minimum temperature is also high.

  On the other hand, with respect to A1 to H3, the peripheral portion of the heating pan 7 to which the high-frequency heating element 19 such as the slit hole 21 is not bonded, and further the portion where the temperature does not rise such as the wall surface of the heating chamber 2 and the door 10 are viewed. Since the temperature does not increase, the minimum temperature is low.

  The maximum temperature extraction unit 35 extracts the highest temperature by extracting the lowest temperature of C1 to F8. On the other hand, when food is placed, C1 to F8 contain a low temperature portion, so the lowest temperature is low, and A1 to H3 also includes a portion where the temperature does not rise, so the lowest temperature is low. Even if the highest temperature extraction unit 35 extracts the higher temperature in the low temperature, it is low temperature.

  As described above, the maximum temperature extraction unit 35 extracts the maximum temperature from the minimum temperatures extracted by the plurality of minimum temperature extraction units 25, so that the food can be loaded regardless of whether the heating pan 7 is in the upper stage or the lower stage. If the food is placed, the temperature is extracted. If the food is not placed, the high temperature is extracted, and it is possible to determine whether the food is placed.

  The operation of the fourth embodiment will be described using the flowchart of FIG. In FIG. 15, the same processes as those in FIG.

  When the user puts food such as fish on the heating pan 7 and attaches it to the upper or lower tray hook 8 of the heating chamber 2 and closes the open / close door 9 to start heating, the heating control means 15 First, in S1, the magnetron 3 is driven to start high-frequency heating in the heating chamber 2.

  In S41, the temperature distribution of A1 to H8 is detected by the infrared sensor 12. In S42, the minimum temperature extraction unit 25 extracts the minimum temperatures Tminx of A1 to H3 among them. In S43, another lowest temperature extraction unit 25 extracts the lowest temperature Tmin of C1 to F8. In S44, the maximum temperature extraction unit 35 extracts the higher one of Tminx and Tminy as the maximum temperature Tmax.

  In S45, the maximum temperature Tmax is compared with a predetermined temperature Tmaxs. If the temperature is lower than the predetermined temperature Tmaxs, the process proceeds to S6, and if it is higher, the process proceeds to S4 and the magnetron 3 is stopped.

  This is because the high temperature is detected, that is, it is determined that no food is placed on the heating pan 7, and the magnetron 3 is stopped for safety. In S5, the user is informed that no food is placed, and the process is terminated.

  In S6, it is determined whether or not the elapsed time from the start of the high frequency heating by the magnetron 3 counted by the timer 17 has passed the predetermined time t1, and if it has already elapsed, the process proceeds to S7, but if it has not yet elapsed. Returning to S41, detecting the temperature distribution of A1 to H8, extracting the lowest temperature of A1 to H3 in S42, extracting the lowest temperature of C1 to F8 in S43, extracting the highest temperature Tmax among the plurality of lowest temperatures, highest in S45 The comparison between the temperature Tmax and the predetermined temperature Tmaxs is repeated. The operations after S7 are the same as those in the first embodiment shown in FIG.

  Here, when the predetermined time t1 is, for example, 1 minute, when the heating dish 7 is mounted without placing food and high-frequency heating is performed by the magnetron 3, when the heating dish 7 is in the upper stage, Vx is in the lower stage. When the Vy region rises to 100 ° C. or higher, the minimum temperature of either is 100 ° C. or higher.

  On the other hand, when food is placed on the heating pan 7 and subjected to high-frequency heating, Vx when the heating pan 7 is in the upper stage is about 50 to 60 ° C. near the food, even if the food is not in view, Vy Is about 40 ° C at the handle portion 20, so even if the one with the lowest temperature is extracted, it will be about 50 ° C. Even if it is close to food, Vx is about 50 to 60 ° C., Vx is about 30 ° C. for the wall surface of the heating chamber 2 and the door 10, and the higher one is extracted and is about 50 ° C.

  Therefore, if Tmaxs is set to 70 ° C., for example, if no food is placed on the heating pan 7, the process proceeds to S4 within one minute regardless of whether the food is on the upper stage or the lower stage, and the heating is stopped. If the food is placed on the heating pan 7, the process proceeds to S7 after 1 minute regardless of whether the food is on the upper stage or the lower stage and is appropriately heated.

  As described above, in the fourth embodiment, the minimum temperature in a plurality of predetermined ranges is extracted, the maximum temperature is extracted from the plurality of minimum temperatures, and the food is placed on the heating pan at the maximum temperature. Therefore, it is possible to determine the presence or absence of food regardless of the height of the heating pan, and to stop the heating when there is no food to ensure safety.

  In the fourth embodiment, whether or not the food is placed on the heating pan 7 is determined based on whether or not the maximum temperature extracted from the minimum temperatures of the temperature detection points in a plurality of predetermined ranges exceeds the predetermined temperature Tmaxs. However, as described in the second embodiment, the temperature detected in the initial stage is stored, the temperature difference with the temperature is calculated, and based on the temperature difference, from among the minimum temperature differences in a plurality of predetermined ranges. It may be determined whether or not food is placed on the heating pan 7 based on whether or not the extracted maximum temperature difference exceeds a predetermined temperature difference.

  In this case, it is difficult to be influenced by the atmospheric temperature or the temperature when repeatedly heated, and the presence or absence of food on the heating pan can be determined more accurately.

  As described above, in the first to fourth embodiments, the food detection unit 16 has been described as stopping the magnetron 3 when it is determined that no food is placed on the heating pan 7, but ensuring safety. Therefore, the high frequency heating may be continued by reducing the output to a level where safety can be ensured instead of stopping.

  Since it is up to the user where the food is placed on the heating pan 7, the food is placed extremely far from the visual field Vx or Vy of the infrared sensor 13, or an extremely small food is placed. There is a possibility that it is determined that the food is not placed even though the food is placed.

  At that time, the user's purpose may be achieved by heating the burnt pottery even if it takes a long time by heating at a reduced output rather than stopping the heating. is there.

  As described above, the present invention determines whether food is placed on the heating dish from the temperature rise of the heating dish by the infrared sensor, and reduces or stops the heating output when it is determined that there is no food. In addition to ensuring safety, it can be applied to a cooking device that heats food using a heating dish with a high-frequency heating element attached. It can be applied as a safety device.

2 Heating chamber 3 Magnetron (high frequency generation means)
7 Heating dish 8 Dish hanging part 13 Infrared sensor 15 Heating control means 16 Food detection part 17 Timer 19 High frequency heating element 24 Temperature difference calculation part 25 Minimum temperature extraction part 35 Maximum temperature extraction part

Claims (2)

And high-frequency onset generating means,
A heating dish on which a high-frequency heating element that generates heat by receiving high-frequency from the high-frequency generating means is attached;
A heating cabinet to which the heating dish is mounted;
Temperature distribution detecting means for detecting a plurality of temperatures on the surface of the heating dish ; and
Heating control means for controlling the high-frequency generation means,
The heating control unit includes a food detection unit that determines the presence or absence of food on the heating dish based on the temperature distribution detected by the temperature distribution detection unit, and the food detection unit detects the temperature distribution detection unit. A minimum temperature extraction unit for extracting a minimum temperature from temperature detection points in a predetermined range, and determining the presence or absence of food on the heating dish based on the minimum temperature extracted by the minimum temperature extraction unit; A cooking device that reduces or stops the output of the high-frequency generating means when it is detected that there is no food. And high-frequency onset generating means,
A heating dish on which a high-frequency heating element that generates heat by receiving high-frequency from the high-frequency generating means is attached;
A heating cabinet to which the heating dish is mounted;
Temperature distribution detecting means for detecting a plurality of temperatures on the surface of the heating dish; and
Heating control means for controlling the high-frequency generation means,
The heating chamber has a plurality of dish hanging portions that can set a height for mounting the heating dish,
The heating control means includes a minimum temperature extraction unit that extracts a minimum temperature from a plurality of temperature detection points in different predetermined ranges detected by the temperature distribution detection unit, and a minimum temperature extracted by the minimum temperature extraction unit. A maximum temperature extraction unit for extracting the maximum temperature from the food, and a food detection unit for determining the presence or absence of food on the heating dish based on the maximum temperature extracted by the maximum temperature extraction unit, and there is no food by the food detection unit A cooking device that reduces or stops the output of the high-frequency generating means when it is detected.

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