Heating cooker

Abstract

The present application provides a heating cooker capable of realizing a thawing function without complicating the structure of the device. The heating cooker is provided with a generating unit generating microwaves and a control unit controlling the microwave output from the generating unit. In a thawing mode for thawing a cooking object, the control unit controls the microwave output by a combination of a first intermittent output of a minimum rated microwave output of the generating unit and a second intermittent output of the minimum rated microwave output, the second intermittent output having the same period as the first intermittent output and a different duty cycle from the first intermittent output.

Description

Technical Field

[0001] This invention relates to a heating cooker. Background Technology

[0002] Among heating appliances such as microwave ovens that heat food using microwave heating, there are those with a defrosting function for defrosting frozen food. In defrosting mode, it is necessary to prevent overheating of the food and to prevent uneven defrosting (achieving uniform defrosting).

[0003] For example, in Patent Document 1, to prevent overheating, the following control is implemented: by setting the microwave output to a low value and intermittently turning the microwave output on and off, the average output over the total time is reduced. Additionally, in Patent Document 1, to prevent uneven thawing, the following control is also implemented: the microwave output is controlled based on the detection results obtained using an infrared sensor to detect the temperature distribution of the object and the detection results obtained using a temperature sensor to detect the temperature inside the chamber.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-54250 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] Uniform thawing can be achieved by controlling the microwave output according to the temperature distribution of the object being tested. However, this method requires numerous sensors to monitor the temperature distribution sequentially while controlling the microwave output, which complicates the device structure and increases costs. Alternatively, there are thawing control techniques that do not use such sensors, but these have limitations such as requiring a dedicated thawing tray.

[0009] This invention provides a heating cooker that can achieve the defrosting function without complicating the device structure.

[0010] Solution for solving the problem

[0011] According to one aspect of the present invention, a heating cooker is provided that heats an object to be cooked disposed in a storage compartment by radiating microwaves into the storage compartment. The heating cooker includes: a generating unit that generates microwaves; and a control unit that controls the microwave output from the generating unit. In a defrosting mode for defrosting the object to be cooked, the control unit controls the microwave output by a combination of a first intermittent output of the lowest rated microwave output value of the generating unit and a second intermittent output of the lowest rated microwave output value, wherein the second intermittent output has the same period as the first intermittent output, and the duty cycle of the second intermittent output is different from the duty cycle of the first intermittent output.

[0012] The effects of the invention

[0013] According to the present invention, a heating cooker that can achieve the defrosting function without complicating the device structure can be provided. Attached Figure Description

[0014] Figure 1 This is a cross-sectional view of the main parts of the heating cooker.

[0015] Figure 2 This is the function block diagram of the control system.

[0016] Figure 3 This is a diagram showing an example of the appearance and structure of the operation panel.

[0017] Figure 4 This diagram illustrates the heating operation in defrosting mode.

[0018] Figure 5 This is a flowchart illustrating the control process of heating operation in defrosting mode. Detailed Implementation

[0019] The embodiments will now be described in detail with reference to the accompanying drawings. Furthermore, the embodiments described below are not limited to the invention as defined in the claims, and not all combinations of features described in the embodiments are necessary for the invention. Any combination of two or more features described in the embodiments may be used. Additionally, the same reference numerals are used to denote the same or identical structures, and repeated descriptions are omitted.

[0020] Figure 1 This is a cross-sectional view of the main part of the heating cooker 1 in the embodiment. The heating cooker 1 can be a so-called microwave oven, which heats the food to be cooked placed in the storage compartment by radiating microwaves into the storage compartment. The heating cooker 1 includes a power supply 2, a magnetron 3, a waveguide 4, and a storage compartment 5 for storing the food 6, which is the food to be cooked.

[0021] Power supply 2 applies a predetermined voltage to magnetron 3 via a transformer or inverter. When the predetermined voltage is applied from power supply 2 to magnetron 3, which serves as the microwave generator, 2.45 GHz microwaves are generated. The microwaves generated from magnetron 3 are guided into storage compartment 5 (inside the compartment) via waveguide 4.

[0022] The storage container 5 is made into a sealed space by closing the front surface door (not shown) of the storage container 5. A tray 7 for holding food 6 is arranged inside the storage container 5. A rotating antenna 8 is arranged below the tray 7. The rotating antenna 8 radiates microwaves guided by the waveguide 4 and stirs the microwaves within the storage container 5. The rotating antenna 8 can be driven to rotate by an antenna motor 9. Furthermore, the arrangement of the waveguide 4 and the rotating antenna 8 is not limited to this; for example, the waveguide 4 and the rotating antenna 8 can be arranged above the storage container 5. Alternatively, instead of using the rotating antenna 8, the tray 7 can be used as a turntable, which is driven to rotate during microwave radiation.

[0023] In addition, a control panel 10 is provided on the heating cooker 1. A control unit (described later) is installed on the control panel 10 to uniformly control the operation of the heating cooker 1. The control unit can perform manual operation by combining the selection of microwave output strength with operation time, and automatic operation corresponding to the heating menu. In automatic operation, it can monitor the temperature, humidity, weight of the food 6, infrared radiation generation, etc., while operating. However, a temperature sensor for detecting the temperature inside the heat exchanger, a humidity sensor for detecting the increase in humidity due to water vapor generated from the food 6, a weight sensor for detecting the weight of the food, and an infrared sensor for detecting the infrared radiation dose generated from the food 6 can be appropriately provided on the heating cooker 1. In addition, a front door opening / closing detection mechanism, a heat exchanger light, a heat exchanger cooling fan, a notification unit, etc., can also be assembled on the heating cooker 1. However, these are conventionally used devices and are not particularly relevant to the present invention; therefore, detailed descriptions of their structures and the processes performed using them are omitted here.

[0024] In this embodiment, the rated microwave output (rated high-frequency output, so-called "microwave oven output") of the magnetron 3 (generating unit) is, for example, 900W, 600W, 500W, or 300W, and the magnetron 3 can be used by switching these outputs. These output values ​​are those that allow the magnetron 3 to oscillate continuously. When heating is performed at an output lower than 300W, which is the minimum rated microwave output value, the heating is achieved by intermittent output of 300W. This is because the magnetron 3 stops oscillating when the continuous output is below 300W.

[0025] exist Figure 2The diagram shows a functional block diagram of the control system mounted on the control board 10. A control unit 20, a magnetron driver 21, a motor driver 22, and a display controller 25 can be mounted on the control board 10. The control unit 20 can be a general-purpose computer comprising a memory for storing programs and data, and a CPU. Alternatively, the control unit 20 can be implemented using a special-purpose device such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The magnetron driver 21 includes a drive circuit for driving the magnetron 3, which may include a high-frequency transformer and / or an inverter circuit. Furthermore, such a magnetron driver 21 can also be integrated into the power supply 2. The motor driver 22 may include a drive circuit for driving the antenna motor 9. The display controller 25 controls the display of the display unit 24. For example, an operation panel 30 is disposed on the front panel door, where the display unit 24 is mounted. The display unit 24 is, for example, an LCD (Liquid Crystal Display), in which case the display controller 25 may include an LCD drive circuit. In addition, an operation unit 23 is provided on the operation panel 30, and signals from the operation unit 23 are input to the control unit 20.

[0026] exist Figure 3 The diagram shows an example of the external structure of the operation panel 30. The operation unit 23 (designator) may include multiple operation keys (operation buttons). Specifically, the operation unit 23 may include a mode key 31, a time / weight key 32, an output switch key 33, an auto menu key 34, a complete key 35, a start key 36, and a cancel key 37. The mode key 31 may include: a defrost key for specifying a "defrost mode" for defrosting food; a rice key for specifying a "rice heating mode" for heating rice; and a beverage key for specifying a "beverage heating mode" for heating beverages. The time / weight key 32 may include: a 10-minute key for specifying the heating operation time in 10-minute increments; a 1-minute key for specifying the heating operation time in 1-minute increments; and a 10-second key for specifying the heating operation time in 10-second increments. In one example, the 1-minute button also functions as a button to specify the weight of food item 6 in units of 100g, and the 10-second button also functions as a button to specify the weight of food item 6 in units of 10g.

[0027] Output switch key 33 is used to switch the microwave output to any of the following: 900W, 600W, 500W, 300W, 200W (equivalent), 100W (equivalent). Automatic menu key 34 is used to specify the menu (type of food) for automatic operation. Complete key 35 is used to adjust the heating intensity or heating time during automatic operation. Start key 36 indicates the start of heating. Cancel key 37 indicates the cancellation of operation or the cessation of heating.

[0028] The display unit 24 displays settings corresponding to operations performed via the operation unit 23, the status of the heating cooker 1, etc. Alternatively, the operation unit 23 may be a touch panel superimposed on the display unit 24.

[0029] Next, refer to Figure 4 This will be used to explain the heating operation in the defrosting mode of this embodiment.

[0030] In defrost mode, even the lowest rated microwave output (300W) would be too strong for continuous operation and unsuitable for defrosting. Therefore, in defrost mode, intermittent output at the lowest rated microwave output (300W) can reduce the average microwave output over the total time.

[0031] Figure 4 (a) illustrates an example of intermittent operation to achieve microwave output equivalent to 200W. In this example, a cycle is set to 29 seconds, with the first 20 seconds designated as the 300W output on and the next 9 seconds as off. Furthermore, the reason for setting a cycle to 29 seconds is that it is assumed the rotating antenna 8 rotates at 30 rpm, and the cycle is made asynchronous with this rotation period. In this case, when the duty cycle is set to D, the average output per cycle is...

[0032] 300·D = 300·(20 seconds / 29 seconds)

[0033] ≈207W

[0034] It can be set to be equivalent to 200W.

[0035] Figure 4 (b) illustrates an example of intermittent operation to achieve a microwave output equivalent to 100W. In this example, the first 10 seconds of a cycle (29 seconds) are set to enable the 300W output, and the next 19 seconds are set to disable it. The average output per cycle in this case is...

[0036] 300·D = 300·(10 seconds / 29 seconds)

[0037] ≈103W

[0038] It can be set to be equivalent to 100W.

[0039] Similarly, it is possible to achieve intermittent operation of other average outputs. For example, in achieving a microwave output equivalent to 150W, the first 15 seconds of a cycle (29 seconds) are set to have 300W output on, and the next 14 seconds are set to have it off. In this case, the average output per cycle is...

[0040] 300·D = 300·(14 seconds / 29 seconds)

[0041] ≈155W

[0042] It can be set to be equivalent to 150W.

[0043] Additionally, to achieve a microwave output equivalent to 90W, the first 9 seconds of a 29-second cycle are set to have 300W output enabled, and the next 20 seconds are set to have it disabled. In this case, the average output per cycle is...

[0044] 300·D = 300·(9 seconds / 29 seconds)

[0045] ≈93W

[0046] It can be set to be equivalent to 90W.

[0047] Furthermore, the specific values ​​and procedures used to determine the microwave output mentioned above are just one example; other values ​​and procedures may also be applied.

[0048] In this embodiment, a hybrid control is performed, combining a first intermittent output at the lowest rated microwave output value with a second intermittent output at the lowest rated microwave output value. The second intermittent output has the same period as the first intermittent output, but its duty cycle differs from that of the first intermittent output. This hybrid control allows for more precise output control than that achieved through single-cycle intermittent output, which is advantageous, for example, in preventing overheating.

[0049] exist Figure 5 The diagram shows a flowchart illustrating the control process of heating operation in defrost mode, executed by the control unit 20. The defrost mode is initiated by pressing the defrost button on mode press 31.

[0050] In step S1, the control unit 20 sets the type of food 6 to be defrosted based on the operation signal from the operation unit 23. For example, let's assume three types for the food: "minced meat / meat slices," "meat (chunks) / fish," and "sashimi." The user can specify the type of food 6 by pressing the defrost button a certain number of times within a specified time. For example, pressing the defrost button once selects "minced meat / meat slices," pressing it twice selects "meat (chunks) / fish," and pressing it three times selects "sashimi." Data indicating the specified type is stored as type setting data in the memory.

[0051] In step S2, the control unit 20 sets the weight of the food 6. In one example, the control unit 20 sets the weight of the food 6 to a predetermined default value (e.g., 100g), and the user can change this weight, for example, using the time / weight key 32. The data representing the specified weight is stored in the memory as weight setting data.

[0052] In step S3, the control unit 20 sets the final heating intensity. In this embodiment, the heating cooker 1 may have four intensity levels: weak, medium (standard), strong 1, and strong 2. However, the number of intensity levels is not limited to a specific number; it may be less than four, more than four, or even none. The control unit 20 sets the medium (standard) intensity as the default value, and the user can change the intensity by operating the finish button 35. The data representing the specified intensity is stored in the memory as the intensity setting data.

[0053] In step S4, the control unit 20 determines the duty cycle of the first intermittent output, i.e., the first duty cycle D1, and the duty cycle of the second intermittent output, i.e., the second duty cycle D2. The method for determining the duty cycle is illustrated below.

[0054] For example, with a minimum rated microwave output of 300W, such as Figure 4 As shown in the example, the control unit 20 determines the first duty cycle D1 to make the microwave output of the first intermittent output equivalent to 200W, and the second duty cycle D2 to make the microwave output of the second intermittent output equivalent to 100W. Alternatively, the control unit 20 may determine the first duty cycle D1 to make the microwave output of the first intermittent output equivalent to 150W, and the second duty cycle D2 to make the microwave output of the second intermittent output equivalent to 100W or 90W.

[0055] Alternatively, if the food type set (specified) in step S1 is "sashimi," the control unit 20 sets the first duty cycle D1 to make the microwave output of the first intermittent output equivalent to 150W, and determines the second duty cycle D2 to make the microwave output of the second intermittent output equivalent to 100W or 90W. On the other hand, if the food type set (specified) in step S1 is not "sashimi," the control unit 20 determines the first duty cycle D1 to make the microwave output of the first intermittent output equivalent to 200W, and determines the second duty cycle to make the microwave output of the second intermittent output equivalent to 100W or 90W. That is, the microwave output when the food is sashimi is further reduced compared to the microwave output when the food is another type. This prevents overheating of the sashimi.

[0056] In step S5, the control unit 20 sets the rated microwave output to 300W as the minimum value.

[0057] In step S6, the control unit 20 checks whether the cancel key 37 has been pressed. If the press of the cancel key 37 is detected, the defrost mode ends. If the press of the cancel key 37 is not detected, the process proceeds to step S7.

[0058] In step S7, the control unit 20 checks whether the start button 36 has been pressed. If no press of the start button 36 is detected, the process returns to step S6. If a press of the start button 36 is detected, the process proceeds to step S8.

[0059] In step S8, the control unit 20 performs a first intermittent output with a first duty cycle D1 determined in step S4. Subsequently, in step S9, the control unit 20 performs a second intermittent output with a second duty cycle D2 determined in step S4.

[0060] The heating operation in the defrosting mode of this embodiment is as described above. Here, based on the example described in relation to step S4, the relationship between the first duty cycle D1 and the second duty cycle D2 determined in step S4 is such that D1>D2. According to this relationship, the microwave output under the first intermittent output in step S8 (e.g., equivalent to 200W) is set to a higher value compared to the microwave output under the second intermittent output in step S9 (e.g., equivalent to 100W). Therefore, in the latter half, the food can be gradually defrosted with a lower output while using the heat from the food heated in the first half to melt the surrounding ice.

[0061] The cycle duration of the first intermittent output performed in step S8 and the second intermittent output performed in step S9 will be explained below. The cycle duration refers to the total time during which the intermittent output cycle is repeatedly executed.

[0062] In this embodiment, the cycle duration of the first intermittent output and the cycle duration of the second intermittent output can be determined based on the weight of the food. For example, the cycle duration of the first intermittent output and the cycle duration of the second intermittent output can be determined based on a polynomial that includes the weight of the food specified in step S2.

[0063] When the weight of the food specified in step S2 is set to M, the cycle duration of the first intermittent output is set to T1, and the cycle duration of the second intermittent output is set to T2, T1 and T2 are represented by the following formula.

[0064] T1=α1·M+β1

[0065] T2=α2·M+β2

[0066] Where α1, α2, β1, and β2 are coefficients for weight M.

[0067] The coefficients α1, α2, β1, and β2 can have values ​​corresponding to the types of food specified in step S1. Examples of the coefficients corresponding to the types of food are shown below. However, these values ​​are just examples, and the coefficients are not limited to these values.

[0068] (1) Minced meat / meat slices (equivalent to 200W + equivalent to 100W):

[0069] α1=0.3, β1=-30, α2=0.75, β2=120

[0070] (2) Meat (pieces) / Fish (equivalent to 200W + equivalent to 100W):

[0071] α1=0.4, β1=-20, α2=0.6, β2=90

[0072] (3) Sashimi (equivalent to 150W + equivalent to 90W):

[0073] α1=0.3, β1=0, α2=1.0, β2=100

[0074] When a specific example is shown, if the type of food is "minced meat / meat slices" and the weight M of the food is set to 200g, the heating operation time T used for defrosting becomes as follows.

[0075] T = Cycle duration T1 of the first intermittent output (equivalent to 200W)

[0076] + Cycle duration of the second intermittent output (equivalent to 100W)

[0077] = (0.3 × 200g - 30) + (0.75 × 200g + 120)

[0078] =300 seconds

[0079] In addition, when the type of food is "sashimi" and the weight M of the food is set to 200g, the heating operation time T for defrosting is as follows.

[0080] T = Cycle duration T1 of the first intermittent output (equivalent to 150W)

[0081] +Cycle duration T2 of the second intermittent output (equivalent to 90W)

[0082] = (0.3 × 200g) + (1.0 × 200g + 100)

[0083] =300 seconds

[0084] Furthermore, the control unit 20 can also adjust the cycle duration T1 of the first intermittent output and the cycle duration T2 of the second intermittent output according to the completion intensity specified in step S3. For example, a coefficient corresponding to the completion intensity is preset. The coefficient for each completion intensity is, for example, the coefficient shown below. However, the values ​​of these coefficients are just examples, and each coefficient is not limited to these values. In addition, the above-mentioned weight-related values ​​are also just examples, and other values ​​can also be applied.

[0085] Weak: 0.9,

[0086] Chinese (Standard): 1,

[0087] Strong 1: 1.1,

[0088] Strong 2: 1.2

[0089] The control unit 20 multiplies the heating operation time T used for defrosting by a coefficient corresponding to the aforementioned completion intensity. For example, when the completion intensity is "weak," the heating operation time is adjusted to 0.9 × T. 0.9 × T, for example, means that the start and stop times of each cycle are each multiplied by 0.9. Similarly, when the completion intensity is "strong 1," the heating operation time is adjusted to 1.1 × T, and when the completion intensity is "strong 2," the heating operation time is adjusted to 1.2 × T.

[0090] In this way, the heating operation time is adjusted by the completion intensity specified by the user. As a result, predictions of the degree of defrosting completion based on the user's experience can be reflected in the heating operation time.

[0091] According to the implementation method described above, the degree of completion of thawing can be maintained, and a thawing function that does not complicate the device structure and is cost-effective can be achieved.

[0092] This invention is not limited to the embodiments described above, and various modifications and alterations can be made within the scope of the invention's intent.

[0093] Explanation of reference numerals in the attached figures

[0094] 1: Heating cooker; 2: Power supply; 3: Magnetron; 4: Waveguide; 5: Storage compartment; 6: Food; 7: Tray; 8: Rotating antenna; 9: Antenna motor.

Claims

1. A heating cooker that heats an object to be cooked within a storage compartment by radiating microwaves into the compartment, characterized in that it comprises: The generating unit generates microwaves; and The control unit controls the microwave output from the generating unit. in, In the defrosting mode for defrosting the object to be cooked, the control unit controls the microwave output by a combination of a first intermittent output of the lowest rated microwave output value of the generator and a second intermittent output of the lowest rated microwave output value. The period of the second intermittent output is the same as the period of the first intermittent output, and the duty cycle of the second intermittent output is different from the duty cycle of the first intermittent output.

2. The heating cooker according to claim 1, characterized in that, The duty cycle of the first intermittent output, i.e., the first duty cycle, is greater than the duty cycle of the second intermittent output, i.e., the second duty cycle. The control unit performs the second intermittent output after performing the first intermittent output.

3. The heating cooker according to claim 2, characterized in that, The minimum rated microwave output is 300W. The first duty cycle is determined to make the microwave output of the first intermittent output equivalent to 200W, and the second duty cycle is determined to make the microwave output of the second intermittent output equivalent to 100W.

4. The heating cooker according to claim 2, characterized in that, The minimum rated microwave output is 300W. The first duty cycle is determined to make the microwave output of the first intermittent output equivalent to 150W, and the second duty cycle is determined to make the microwave output of the second intermittent output equivalent to 100W or 90W.

5. The heating cooker according to claim 2, characterized in that, It also includes a designation section, which designates the type of food to be cooked in the defrost mode. The minimum rated microwave output is 300W. When the type of food to be cooked, as specified by the designating unit, is sashimi, the first duty cycle is determined to make the microwave output of the first intermittent output equivalent to 150W, and the second duty cycle is determined to make the microwave output of the second intermittent output equivalent to 100W or 90W. When the type of food to be cooked, as specified by the designation unit, is not sashimi, the first duty cycle is determined to make the microwave output of the first intermittent output equivalent to 200W, and the second duty cycle is determined to make the microwave output of the second intermittent output equivalent to 100W.

6. The heating cooker according to claim 5, characterized in that, The specified part is configured to also specify the weight of the food to be cooked. The cycle duration of the first intermittent output and the cycle duration of the second intermittent output are determined based on the weight of the object to be cooked, as specified by the designator.

7. The heating cooker according to claim 6, characterized in that, When the weight of the object to be cooked, specified by the designated unit, is set to M, the coefficients for the weight M are set to α1, α2, β1, β2, the cycle duration of the first intermittent output is set to T1, and the cycle duration of the second intermittent output is set to T2, Let α1·M+β1 represent T1. T2 is represented by α2·M+β2.

8. The heating cooker according to claim 7, characterized in that, The coefficients α1, α2, β1, and β2 have values ​​corresponding to the types of cooking objects specified by the designation unit.

9. The heating cooker according to claim 8, characterized in that, The specified part is configured to further specify the complete thawing strength of the cooked object. The control unit adjusts the cycle duration T1 of the first intermittent output and the cycle duration T2 of the second intermittent output according to the completion intensity specified by the designation unit.

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