JP2006061359A - Cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooker capable of improving the cooking performance and the flexibility in the design without using a highly precise temperature sensor or a complicated temperature detecting structure. <P>SOLUTION: The power of a heating means 3 is controlled according to the high pressure boiling detection motion for detecting the operation of a pressure regulating valve 4 by finding the minimum value of the gradient of temperature rise based on the inclination of the temperature rise of a pressure pot 1 measured by a temperature detection means 5, setting a threshold of the gradient of temperature rise according to the minimum value of the gradient of temperature rise, and starting the high pressure boiling detection motion after the gradient of temperature rise of the pressure pot 1 becomes higher than the threshold of gradient of temperature rise. Accordingly, the pressure cooking can be automatically controlled without using a highly precise temperature sensor or a complicated temperature detection structure, so that the cooking performance, the flexibility in the design, the durability in using, and the easiness in the cleaning can be improved. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a cooking device that performs pressure cooking.

  Conventionally, as this type of cooking device, the bottom temperature of the pressure cooker is measured by a temperature sensor arranged so as to contact the bottom of the pressure cooker, and the bottom temperature of the pressure cooker is controlled by the boiling in the pressure cooker. When the pressure cooking temperature lower than the temperature at which steam leakage from the oil reaches a temperature, there are some that control the temperature at a predetermined temperature and some that reduce the amount of heating (for example, see Patent Document 1).

  As shown in FIG. 3, the heating cooker stores the pressure cooker 20 in a fixture main body 21 so as to be detachable and is placed on an electric heating element 22. A pressure adjusting weight 23 that suppresses the pressure inside the pressure cooker 20 to a predetermined pressure or less is installed on the lid of the pressure cooker 20. A temperature sensor 24 for detecting the bottom surface temperature of the pressure cooker 20 is disposed so as to contact the bottom surface of the pressure cooker 20, and the bottom surface temperature detected by the temperature sensor 24 is configured to be transmitted to the control circuit 25. An operation unit 26 is arranged on the side surface of the appliance main body 21 so that information such as setting of cooking time and start of cooking is transmitted to the control circuit 25.

Here, when the cooked food is put in the pressure cooker 20 and placed on the electric heating element 22, the cooking time is set according to the cooked food by the operation unit 26 and the start of cooking is instructed, the control circuit 25 generates the electric heat. Energization of the body 22 is started. When the temperature of the bottom surface of the pressure cooker 20 is detected by the temperature sensor 24 and reaches a predetermined temperature set slightly before the temperature at which the steam is discharged from the pressure adjusting weight 23, the control circuit 25 subtracts the cooking time set by the operation unit 26. The timer is activated, and at the same time, the energization rate to the electric heating element 22 is reduced, or the electric heating element 22 is de-energized. When the temperature sensor 24 detects a decrease in temperature, the temperature control of the pressure cooker 20 is performed by repeating the operation of energizing the electric heating element 22 again. When the cooking time subtraction timer ends, the control circuit 25 stops energization of the electric heating element 22, the pressure in the pressure cooker 20 decreases, and cooking is completed.
JP-A-10-290749

  However, in the conventional configuration, since it is necessary to determine whether or not the pressure cooker 20 has reached a pressure suitable for cooking based on the absolute value of the temperature sensor 24, the absolute value of the temperature sensor 24 and the temperature detection circuit. There was a problem that it was necessary at a high level of accuracy and the cost increased. In addition, in order to increase the accuracy of temperature detection, it is necessary to adopt a sensor configuration that contacts the pressure cooker 20 on the surface, and the movable configuration of the temperature sensor 24 and the exposure of the contact surface cannot be avoided, resulting in an increase in cost and design. However, there were problems that the limit of durability, deterioration of durability of use, and deterioration of careability were unavoidable.

  The present invention solves the above-mentioned conventional problems, does not require a high-accuracy temperature sensor, a temperature detection circuit, a temperature sensor configuration that directly contacts the pressure cooker, improves cooking performance and design flexibility, It is an object of the present invention to provide a cooking device that achieves improved durability and care.

  In order to solve the above-mentioned conventional problems, the cooking device of the present invention obtains the minimum value of the temperature rising gradient based on the temperature rising tendency of the pressure cooker measured by the temperature detecting means, and responds to the minimum value of the temperature rising gradient. The temperature rise gradient threshold is set, and after the pressure cooker temperature rise gradient exceeds the temperature rise gradient threshold, the high pressure boiling detection operation is started to detect the operation of the pressure regulating valve. The power of the heating means is controlled according to the above.

  This allows automatic control of pressure cooking without using a high-accuracy temperature sensor or complicated temperature detection configuration, improving cooking performance and design freedom, improving durability, and maintenance The improvement of property can be realized.

  The heating cooker of the present invention can realize pressure cooking using an inexpensive temperature sensor with general accuracy and a non-contact type high sensor design configuration for the pressure cooker.

  1st invention is the pressure cooker which performs pressure cooking, the pressure control valve which suppresses the pressure in the said pressure cooker below to predetermined pressure, the heating means which heats the said pressure cooker, and the temperature of the said pressure cooker A temperature detecting means for measuring, and a control section for controlling the heating means, wherein the control section obtains the minimum value of the temperature rising gradient based on the temperature rising tendency of the pressure cooker measured by the temperature detecting means, A high pressure boiling detection operation for setting the temperature rising gradient threshold value corresponding to the minimum value of the rising gradient and detecting the operation of the pressure regulating valve after the temperature rising gradient of the pressure cooker exceeds the temperature rising gradient threshold value. The cooking device is configured to control the power of the heating means according to the high-pressure boiling detection operation, so that pressure cooking can be performed without using a high-precision temperature sensor or a complicated temperature detection configuration. Can be controlled automatically and cookability Improvement and flexibility improvement of the design of, improvement of use durability, it is possible to realize the improvement of care of.

  In a second aspect of the invention, in particular, in the first aspect of the invention, the control unit sets a measurement start temperature for starting measurement of the temperature rise tendency of the pressure cooker for obtaining the minimum value of the temperature rise gradient, and is set to be higher than the measurement start temperature. Since the minimum value of the temperature increase gradient is not measured at low temperatures, the minimum value of the temperature increase gradient is about 1 atm when the temperature detection means relative to the pan temperature is not stable immediately after the start of cooking. Malfunction at the start of the high pressure boiling detection operation due to the boiling of the water adhering to the pan bottom at a time earlier than the temperature in the pressure cooker being detected or the content in the pressure cooker boiling near 1 atm. Therefore, it is possible to realize a cooking device with high pressure cooking performance.

  The third aspect of the invention includes, in particular, the temperature detection sensitivity measurement means for measuring the sensitivity of the temperature detection means in the first or second aspect of the invention, and the control unit is provided with the temperature detection means measured by the temperature detection sensitivity measurement means. By changing the measurement start temperature to start measuring the temperature rise tendency of the pressure cooker to obtain the minimum value of the temperature rise gradient according to the temperature detection sensitivity, the difference in the pot bottom shape of the pressure cooker and the pot bottom and temperature Even when a gap or a foreign object adheres to the detection means, it is possible to prevent a malfunction at the start of the high-pressure boiling detection operation and to realize a cooking device with high pressure cooking performance.

  In particular, in any one of the first to third inventions, the fourth invention is provided with an internal capacity input means for inputting the internal capacity in the pressure cooker to the control section, and the control section is provided by the internal capacity input means. By changing the measurement start temperature to start measuring the temperature rise tendency of the pressure cooker for obtaining the minimum value of the temperature rise gradient according to the content in the pressure cooker obtained, the contents of the contents in the pressure cooker are changed. A malfunction at the start of the high-pressure boiling detection operation can be accurately prevented according to the amount, and a cooking device with high pressure cooking performance can be realized.

  The fifth aspect of the invention includes, in particular, the temperature detection sensitivity measurement means for measuring the sensitivity of the temperature detection means in the first or second aspect of the invention, and the control unit is provided with the temperature detection means measured by the temperature detection sensitivity measurement means. By changing the temperature rise gradient threshold for starting the high pressure boiling detection operation according to the temperature detection sensitivity, there is a difference in the pan bottom shape of the pressure cooker, and there are gaps and foreign objects between the pan bottom and the temperature detection means. Even when it adheres, a boiling state of 1 atm can be detected with high accuracy, and a cooking device with high pressure cooking performance can be realized.

  In particular, the sixth invention includes any one of the first to fifth inventions, further comprising an internal capacity input means for inputting the internal capacity in the pressure cooker to the control section, wherein the control section is more than the internal capacity input means. By setting the time limit from the start of cooking according to the content in the pressure cooker obtained, and forcing the high-pressure boiling detection operation to start when the time limit is reached, the amount of content in the pressure cooker Regardless of this, it is possible to prevent a delay in the start of the high-pressure boiling detection operation and to realize a cooking device with high pressure cooking performance.

  According to a seventh aspect of the invention, in particular, in the sixth aspect of the invention, the control unit sets a time limit from the start of cooking according to the initial temperature measured by the temperature detecting means at the start of cooking, and when the time limit is reached, the high pressure boiling detection operation By forcibly starting cooking, it is possible to prevent a delay in starting the high pressure boiling detection operation regardless of the initial temperature of the food in the pressure cooker, and to realize a cooking device with high pressure cooking performance. be able to.

  In the eighth invention, in particular, in the sixth or seventh invention, the timing start point of the time limit is set at the same time when the temperature rise tendency of the pressure cooker for obtaining the minimum value of the temperature rise gradient is started. Therefore, it is possible to accurately prevent the delay in starting the high-pressure boiling detection operation without depending on the difference in the shape of the bottom of the pressure cooker or the gap or foreign matter between the pan bottom and the temperature detection means. A high cooking device can be realized.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment)
FIG. 1 shows a cooking device according to an embodiment of the present invention.

  As shown in the figure, the heating cooker in the present embodiment heats the pressure cooker 1 that performs pressure cooking, the top plate 2 on which the pressure cooker 1 is placed, and the pressure cooker 1 through the top plate 2. Heating means 3, a pressure adjusting valve 4 configured by a pressure adjusting weight that is installed on the lid of the pressure cooker 1 and suppresses the internal pressure to a predetermined pressure or less, and the temperature of the pressure cooker 1 is passed through the top plate 2. A temperature detecting unit 5 for measuring and a control unit 6 for controlling the heating unit 3 according to the temperature detected by the temperature detecting unit 5 are provided.

  The control unit 6 obtains the minimum value of the temperature increase gradient based on the temperature increase tendency of the pressure cooker 1 measured by the temperature detecting means 5, and sets a temperature increase gradient threshold value corresponding to the minimum value of the temperature increase gradient. After the temperature rise gradient of the pressure cooker 1 exceeds the temperature rise gradient threshold value, a high pressure boiling detection operation for detecting the operation of the pressure regulating valve 4 is started, and the power of the heating means 3 is determined according to the high pressure boiling detection operation. I try to control it.

  In addition, the cooking device in the present embodiment includes an operation unit 7 that is operated by the user to transmit the setting of the pressure cooking time and the start of cooking to the control unit 6, and a control unit when the subtraction of the timer ends. The user operates the pressure cooking timer 8 for transmitting the timer timing completion to the timer 6, the temperature detection sensitivity measuring means 9 for measuring the sensitivity of the temperature detection means 5 for detecting the bottom temperature of the pressure cooker 1 and transmitting it to the controller 6, and the user's operation. The internal capacity input means 10 is also provided for transmitting the content of the contents of the pressure cooker 1 to the control unit 6.

  About the cooking-by-heating machine comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the food is put in the pressure cooker 1 and the pressure adjustment valve 4 is set. When the pressure cooker 1 is placed at a predetermined position on the top plate 2, a pressure cooking time is set by the operation unit 7, and an instruction to start cooking is given, the control unit 6 energizes the heating means 3 to turn on the pressure cooker 1. Heat. When the temperature of the pressure cooker 1 rises and boiling at 1 atm begins, the pressure inside the pressure cooker 1 rises, and the temperature at the bottom of the pressure cooker 1 continues to rise. Further, heating by the heating means 3 is continued, and when the atmospheric pressure in the pressure cooker 1 reaches a predetermined pressure set by the pressure regulating valve 4, the pressure regulating valve 4 is actuated to release the steam in the pressure cooking pot 1, The atmospheric pressure in the pressure cooker 1 is maintained at a predetermined pressure set by the pressure adjustment valve 4.

  FIG. 2 shows the temperature change of the temperature detection means 5, cooking is started at time t 0 when the temperature of the temperature detection means 5 is θ 0, and the control unit 6 controls the heating means 3 to control the top plate 2. Heat the pressure cooker 1 over it. The temperature detection means 5 always detects the bottom temperature of the pressure cooker 1 through the top plate 2 after the start of cooking, and the controller 6 increases the temperature once, for example, in order to know the tendency of the temperature rise. I keep timing the time it takes.

  In order to search for a state in which the tendency of the temperature rise is the slowest, the stored maximum time is updated if the time taken for the temperature to rise once is longer than the maximum time measured until the previous time. Since the temperature rise rate of the pressure cooker 1 is deprived of energy by the heat of vaporization as the moisture in the pressure cooker 1 approaches 100 ° C., the temperature rise rate of the pressure cooker 1 becomes the slowest immediately after the boiling time t3 of 1 atm. . Therefore, because of the detection delay time of the temperature detection means 5, the temperature rise speed of the temperature detection means 5 is the slowest at time t4, and the temperature rise slope at that time is defined as the slope Amin.

  However, if the temperature rising tendency of the temperature detecting means 5 with respect to the temperature rising tendency of the pressure cooker 1 is not stable at the beginning of cooking, or if moisture is attached to the bottom of the pressure cooker 1, the contents of the pressure cooker 1 Since the temperature at the bottom of the pan reaches the boiling point prior to the start of boiling and the temperature rise rate of the temperature detecting means 5 is temporarily slowed by the heat of vaporization of the water at the bottom of the pan, the temperature rise rate is the slowest. There is a risk of false detection. Therefore, until the time t2 when the detected temperature of the temperature detecting means 5 reaches the preset temperature θ1, the search for the maximum time spent for the detected temperature to rise once is not performed, and the detected temperature reaches the time t2. Only after that, a search is made for the maximum value of the time spent increasing once.

  Here, if the thickness of the top plate 2 is uniform, the detection sensitivity of the temperature detection unit 5 varies depending on the distance between the bottom of the pressure cooker 1 that is directly above the temperature detection unit 5 and the top plate 2. Therefore, in order to examine the detection sensitivity of the temperature detection means 5, the temperature detection sensitivity measurement means 11 is heated to a constant time t1 with a constant heating power of 1000 W, for example, immediately after the start of cooking, and measures the temperature rise during that time. Only the bottom of the pan is heated before the temperature of the contents of the pressure cooker 1 rises due to the constant heating power for a short time, so the internal volume can be measured by measuring the rate at which the temperature detecting means 5 rises in response to the pan bottom temperature. It can be estimated that the detection sensitivity of the pan bottom temperature can be determined regardless of the temperature, and that the detection sensitivity is high if the temperature rise at this time is large, and the detection sensitivity is low if the temperature rise is small.

  When the detection sensitivity of the temperature detection means 5 is low, compared to when the detection sensitivity is high, the detection delay with respect to the change in the pan bottom temperature of the pressure cooker 1 and the slowing down with respect to the change rate of the pan bottom temperature become large. Therefore, the difference between the temperature at the bottom of the pressure cooker 1 and the temperature detected by the temperature detection means 5 changes due to the influence of the detection sensitivity, and the search for the maximum value of time spent for the detection temperature of the temperature detection means 5 to rise once. The difference between the temperature θ1 at which the cooking is started and the bottom temperature of the pressure cooker 1 also changes. Therefore, in order to offset the influence of the detection sensitivity, the influence on the temperature θ1 can be reduced by correcting the temperature θ1 by the detection sensitivity. (Table 1) is an example showing the correction of the temperature θ1 by the temperature detection sensitivity and the temperature rise gradient threshold value in the present embodiment.

  For example, when the temperature detected by the temperature detecting means 5 is 3.5 degrees from time t0 to time t1, it can be determined that the sensitivity is slightly lower than in (Table 1), and the temperature θ1 at that time The correction value is −4 degrees. Therefore, when the detected temperature of the temperature detecting means 5 reaches a temperature 4 degrees lower than the temperature θ1, the search for the maximum value of the time spent for increasing the detected temperature of the temperature detecting means 5 once is started.

  In addition, when the heating power of the heating means 3 is constant, the temperature rise rate of the pressure cooker 1 is slow when the amount of the content of the pressure cooker 1 is large, and the temperature rise rate is fast when the amount of the content is small. Since there is a detection delay of the temperature detecting means 5, the difference in temperature rise speed appears as a difference in the detected temperature of the temperature detecting means 5 with respect to the same bottom temperature of the pressure cooker 1. Accordingly, the difference between the temperature θ1 at which the detection of the temperature detected by the temperature detection means 5 increases once and the temperature θ1 at which the maximum temperature is started and the bottom temperature of the pressure cooker 1 changes. In order to cancel the influence, the influence on the temperature θ1 can be reduced by correcting the temperature θ1 by the amount of contents. Here, as a means for transmitting the amount of the contents of the pressure cooker 1 to the control unit 6, it is possible to detect the internal volume using the temperature rise value of the temperature detecting means 5 at a constant heating power for a certain period of time. It is difficult to accurately detect the content at the previous stage. Therefore, here, correction is performed based on the content information input in advance by the user from the operation unit 7 before cooking is started. In addition, the data which a user inputs from the operation part 7 provides the water level line which numbered every capacity | capacitance inside the pressure cooker 1, for example, the method of inputting content volume in the unit of a liter or cc, and the number is shown. There are a method of inputting, a method of inputting the number of measuring cups by measuring cups, and the like. In this embodiment, a method of inputting the number of measuring cups will be described. (Table 2) is an example showing the temperature θ1 correction by the internal capacity and the upper limit time t1m in the present embodiment.

  For example, when the content set by the user from the operation unit 7 before starting cooking is 4 cups, the correction value of the temperature θ1 is −2 degrees from (Table 2). Accordingly, when the detected temperature of the temperature detecting means 5 reaches a temperature that is two degrees lower than the temperature θ1, the search is started to search for the maximum value of the time spent for the detected temperature of the temperature detecting means 5 to rise once.

  It should be noted that the correction of the temperature θ1 in (Table 1) and the correction of the temperature θ1 in (Table 2) can be added up. That is, when the sensitivity detection level is slightly low and the content is 4 cups, the correction value of the temperature θ1 is a sum of −4 degrees and −2 degrees, −6 degrees.

  When cooking is further advanced and the contents of the pressure cooker 1 reach the boiling point and the boiling of 1 atm is continued, the pressure in the pressure cooker 1 starts to rise due to the generation of steam. Thereby, since the boiling point in the pressure cooker 1 begins to rise, the temperature of the pressure cooker 1 repeats rising again, and the temperature rise rate of the temperature detection means 5 begins to increase again. By detecting this change in the temperature increase rate, it is possible to detect the boiling of 1 atm, and it is 2/2 of the time required to increase once in the inclination Amin which is the minimum value of the temperature increase inclination of the temperature detecting means 5. Detection of high-pressure boiling for detecting that the pressure regulating valve 4 operates is started at time t5 when it is detected that the pressure rises once in a time less than 3. The temperature rise inclination at that time is the inclination A1. In the above, the gradient A1 with respect to the gradient Amin is a temperature increase gradient threshold value, and the temperature increase gradient of the temperature detected by the temperature detection means 5 is not less than A1, that is, less than 2/3 of the time required for the gradient Amin to rise once. It is operated so as to complete the detection of boiling at 1 atm and to start detecting high-pressure boiling by detecting a rise of 1 degree in the period of time.

  In the structure of the pressure cooker 1, when the pressure valve installed in the lid is closed by the flow force of the steam generated by boiling at 1 atmosphere, steam is supplied from the pressure valve until the pressure valve is closed. By discharging, the minimum value of the temperature rise slope of the temperature detecting means 5 becomes smaller, and there is a case where the difference from the temperature rise slope after boiling at one atmosphere appears more prominently.

  Here, the temperature rise gradient threshold means the rate of change of the temperature rise slope of the temperature detection means 5, but if the detection sensitivity of the temperature detection means 5 is low, the change in the temperature rise slope of the pressure cooker 1 bottom temperature. Even if the rate is the same, the rate of change of the temperature rise slope of the temperature detecting means 5 is reduced. Therefore, in order to cancel out the influence of the detection sensitivity, the influence on the one-atmosphere boiling detection can be reduced by correcting the temperature rise gradient threshold value by the detection sensitivity.

  An example of the temperature increase gradient threshold value with respect to the detection sensitivity of the temperature detection means 5 can be expressed as shown in (Table 1). For example, when the temperature at which the temperature detected by the temperature detecting means 5 rises from time t0 to time t1 is 3.5 degrees, it can be determined that the sensitivity is slightly lower than in (Table 1), and the temperature rise gradient at that time The threshold is 5/6. Therefore, when the detection sensitivity of the temperature detection means 5 is slightly low, the detection of 1 atmospheric pressure boiling is detected when it is detected that the temperature rises once in less than 5/6 of the time required to rise once in the inclination Amin. Complete and operate to initiate high pressure boiling detection.

  By the way, depending on conditions such as the content of the pressure cooker 1, the type of contents, and the detection sensitivity of the temperature detection means 5, the temperature detection means 5 has a boiling point of 1 atm. It can be assumed that the temperature increase gradient does not exceed the temperature increase gradient threshold. In that case, since the boiling point of 1 atm is reached and the boiling point of the high pressure is reached and the temperature rise gradient further decreases, there is a possibility that the process cannot be completed indefinitely. Therefore, an upper limit time t1m from the cooking start time t0 is provided for completion of detection of boiling at 1 atm. Since the detected temperature rise rate of the temperature detecting means 5 varies depending on the content of the pressure cooker 1, the upper limit time t1m needs to be determined according to the content of the pressure cooker 1.

  An example of setting the upper limit time t1m with respect to the content of the pressure cooker 1 can be expressed as shown in (Table 2). For example, when the content set by the user from the operation unit 7 before starting cooking is 4 cups, From Table 2), the upper limit time t1m is 950 seconds. Accordingly, when 1 atmosphere boiling detection is not completed until 950 seconds have elapsed from the cooking start time t0, 1 atmosphere boiling detection is forcibly completed and high pressure boiling detection is started.

  In addition, if the initial temperature of the contents of the pressure cooker 1 at the cooking start time t0 is low, it takes a long time to reach a boiling state of 1 atmosphere, and if the initial temperature of the contents is high, until the boiling state of 1 atmosphere is reached. Therefore, if the upper limit time t1m is corrected according to the initial temperature of the contents, the accuracy of the upper limit time t1m can be increased. (Table 3) is an example showing the correction of the upper limit time t1m by the initial temperature θ0 in the present embodiment.

  For example, when the initial temperature θ0 of the temperature detected by the temperature detecting means 5 at the cooking start time t0 is 10 ° C., the correction multiplication factor of the upper limit time t1m is 1.2 from (Table 3). Accordingly, when the internal volume is 4 cups and the initial temperature is 10 ° C., the upper limit time t1m is 1.2 times 950, which is 1140 seconds, so that 1 atmospheric pressure boiling detection is performed until 1140 seconds have elapsed from the time t0 when cooking is started. When not completed, the operation is performed to forcibly complete the 1-atmosphere boiling detection and start the high-pressure boiling detection.

  Further, in order to improve the accuracy of the detection of 1 atmospheric pressure boiling, the temperature from the temperature θ1 that starts searching for the maximum value of the time that the temperature detection means 5 takes to rise once by the completion of the detection of boiling of 1 atmospheric pressure. An upper limit time t1m2 is provided. Since the detected temperature rise rate of the temperature detecting means 5 varies depending on the content of the pressure cooker 1, the upper limit time t1m2 needs to be determined according to the content of the pressure cooker 1. (Table 4) is an example showing the upper limit time t1m2 depending on the internal capacity in the present embodiment.

  For example, when the content set by the user from the operation unit 7 before the start of cooking is 4 cups, the upper limit time t1m2 is 550 seconds from (Table 4). Accordingly, the detection of 1 atm boiling is not completed until 550 seconds have elapsed from the temperature θ1 at which the search for the maximum value of time spent for the detection temperature of the temperature detecting means 5 to rise once upon completion of 1 atm boiling detection is started. Sometimes, it operates to forcibly complete 1 atm boiling detection and start high pressure boiling detection.

  If high pressure boiling is detected by means such as temperature saturation detection after time t5, high pressure boiling can be maintained if the pressure cooker 1 is continuously supplied with a heating power that keeps operating the pressure regulating valve 4 in the subsequent boiling maintaining process. The electric power of the heating means 3 is set to 300 W obtained experimentally as a heating power capable of continuing the operation state of the pressure regulating valve 4. At the same time, the pressure cooking time set by the user before the start of cooking is transferred to the pressure cooking timer 8 by the operation unit 7 and the subtraction timer is activated. When the subtraction of the pressure cooking timer 8 is completed, the control unit 6 notifies the end of the pressure cooking and at the same time stops energizing the heating means 3.

  As described above, in the present embodiment, the minimum value of the temperature increase gradient is obtained based on the temperature increase tendency of the pressure cooker 1 measured by the temperature detecting means 5, and the temperature increase gradient is determined according to the minimum value of the temperature increase gradient. A threshold value is set, and after the temperature rise gradient of the pressure cooker 1 exceeds the temperature rise gradient threshold value, a high pressure boiling detection operation for detecting the operation of the pressure regulating valve 4 is started, and according to the high pressure boiling detection operation. By controlling the power of the heating means 3, it is possible to perform automatic pressure cooking control without using a highly accurate temperature sensor or a complicated temperature detection configuration. Even if the temperature detection means 5 is not in direct contact with the pressure cooker 1 via the top plate 2 as in the present embodiment, the absolute temperature accuracy of the temperature detection means 5 is not required to be so high. Can be automatically controlled. Therefore, a cooking device having a high degree of design freedom and good care can be realized. In addition, it is not detected by absolute temperature, but it is configured to detect boiling at high pressure after detecting a boiling state near the atmospheric pressure due to a temperature rising trend, so even when used at high altitude where the atmospheric pressure is low, Boiling detection and high-pressure boiling detection can be performed.

  Moreover, by setting the detection temperature of the temperature detection means 5 which starts the search of the minimum value of a temperature rise gradient according to the curvature of the pan of the pressure cooker 1, adhesion of the foreign material to the pan bottom, and the amount of the cooked food, Regardless of the difference, the malfunction at the start of the high-pressure boiling detection operation can be prevented with high accuracy, and high pressure cooking performance can be ensured.

  Further, by changing the temperature rise gradient threshold value for starting the high-pressure boiling detection operation according to the detection sensitivity of the temperature detection means 5 due to warpage of the pan of the pressure cooker 1 or foreign matter adhering to the pan bottom, the pan bottom of the pressure cooker 1 is changed. Even when there is a difference in shape, or when a gap or foreign matter adheres between the pan bottom and the temperature detection means, the boiling state of 1 atm can be detected with high accuracy, and high pressure cooking performance can be ensured.

  In addition, by setting a time limit from the start of cooking according to the amount of the cooked food and the initial temperature of the cooked food, the high pressure boiling detection operation is forcibly started when the time deadline is reached. Regardless of the amount of food and the initial temperature, it is possible to prevent a delay in the start of the high-pressure boiling detection operation and to ensure high pressure cooking performance. In addition, by setting the time starting point of the time limit to the same time as the start of measurement of the temperature rise tendency of the pressure cooker 1 for obtaining the minimum value of the temperature rise gradient, It is possible to prevent a delay in starting the high-pressure boiling detection operation with high accuracy and to realize a cooking device with high pressure cooking performance without depending on adhesion of a gap or foreign matter between the temperature detection means 5 and the like.

  In the present embodiment, the control unit 6 measures the time taken for the temperature to rise once in order to know the tendency of the temperature rise. However, the unit of the temperature rise to be measured is 0.5 degree or the like. A value may be used, or a resistance value of a thermistor or a voltage value on a circuit may be used instead of temperature. Further, as a means for knowing the tendency of temperature rise, the temperature rising during a certain time may be measured.

  As described above, the cooking device according to the present invention can realize pressure cooking using an inexpensive temperature sensor with general accuracy and a sensor configuration with high non-contact design for the pressure cooker. In addition to a dedicated pressure cooker, it can also be used as a general-purpose cooking device that can use a general-purpose pan and can also use a pressure cooker.

The block diagram of the heating cooker in embodiment of this invention The figure which shows the temperature change of the temperature detection means in the heating cooker Block diagram of a conventional cooking device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure cooker 3 Heating means 4 Pressure regulating valve 5 Temperature detection means 6 Control part 7 Operation part 9 Temperature detection sensitivity measurement means 10 Contents input means

Claims (8)

A pressure cooker that performs pressure cooking, a pressure adjustment valve that suppresses the pressure in the pressure cooker to a predetermined pressure, a heating device that heats the pressure cooker, and a temperature detector that measures the temperature of the pressure cooker. A control unit for controlling the heating means, the control unit obtains a minimum value of the temperature rise gradient based on the temperature rise tendency of the pressure cooker measured by the temperature detection means, and sets the minimum value of the temperature rise gradient. A corresponding temperature rise gradient threshold is set, and after the temperature rise gradient of the pressure cooker exceeds the temperature rise gradient threshold, a high pressure boiling detection operation for detecting the operation of the pressure regulating valve is started, A cooking device in which the power of the heating means is controlled in accordance with a boiling detection operation. The control unit sets the measurement start temperature to start measuring the temperature rise tendency of the pressure cooker to obtain the minimum value of the temperature rise gradient, and does not measure the minimum value of the temperature rise gradient at a temperature lower than the measurement start temperature. The cooker according to claim 1. A temperature detection sensitivity measuring means for measuring the sensitivity of the temperature detection means, and the control unit is a pressure for obtaining a minimum value of the temperature rise gradient according to the temperature detection sensitivity of the temperature detection means measured by the temperature detection sensitivity measurement means; The cooking device according to claim 1 or 2, wherein a measurement start temperature at which measurement of a temperature rise tendency of the pan is started is changed. An internal volume input means for inputting the internal volume in the pressure cooker to the control unit is provided, and the control unit obtains the minimum value of the temperature rise gradient according to the internal volume in the pressure cooker obtained from the internal volume input unit. The cooking device according to any one of claims 1 to 3, wherein a measurement start temperature at which measurement of a temperature rising tendency of the pressure cooker is started is changed. A temperature detection sensitivity measuring means for measuring the sensitivity of the temperature detection means, and the control unit performs a temperature rise gradient for starting the high-pressure boiling detection operation according to the temperature detection sensitivity of the temperature detection means measured by the temperature detection sensitivity measurement means. The cooking device according to claim 1 or 2, wherein the threshold value is changed. An internal volume input means for inputting the internal volume in the pressure cooker to the control unit is provided, and the control unit provides a time limit from the start of cooking according to the internal volume in the pressure cooker obtained from the internal volume input unit, and the time The cooking device according to any one of claims 1 to 5, wherein when the time limit is reached, the high-pressure boiling detection operation is forcibly started. The control unit provides a time limit from the start of cooking according to the initial temperature measured by the temperature detection means at the start of cooking, and forcibly starts the high-pressure boiling detection operation when the time limit is reached. Cooking device. The cooking device according to claim 6 or 7, wherein the timing start point of the time limit is set at the same time when the temperature rising tendency of the pressure cooker for obtaining the minimum value of the temperature rising gradient is started.

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