JP2009005924A - Grilling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grilling device in which possibility of igniting is reduced when a small amount of cooked objects are cooked by considering an initial temperature at the start of cooking and a period of time elapsed from the start of cooking. <P>SOLUTION: The grilling device includes: a heating source; a temperature sensor for detecting temperature in a grilling case; a temperature/time measuring part for obtaining a period of time required for the temperature detected by the temperature sensor to rise from a lower limit to an upper limit within a judgement range; and a judging part for directing a stop of heating when the time of temperature rise is shorter than a threshold. The threshold ΔT is set as ΔT=A×(TH<SB>0</SB>-α)+B×(TH-β)+C×(t-γ), wherein ΔT is the threshold, TH<SB>0</SB>is the temperature detected at the start of cooking, TH is the current temperature detected by the temperature sensor, t is the period of time elapsed from the start of cooking, and A, B, C, α, β and γ are fixed coefficients. When the number of times the time of temperature rise becomes shorter than the threshold reaches the predefined number of times, an instruction is issued to stop heating by the heating source. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention mainly relates to a grill device attached to a gas range for grilling fish or the like.

Conventionally, in this type of grill device, a bimetal is used to prevent ignition of food in the grill case, and heating is stopped when the inside of the grill case reaches a temperature close to the ignition temperature of the food. Things are offered. In the configuration using bimetal to prevent overheating, heating may be stopped at a constant temperature, and heating may be stopped regardless of the fire of the food. That is, depending on the relationship between the amount of heating by the heating source and the type (mainly fish, dried fish) and amount of the cooked food, there may be a problem that the raw fish becomes burnt or the dried fish ignites. In addition, since bimetal uses thermal expansion, the response is relatively slow and it is difficult to follow instantaneous temperature changes. On the other hand, a grill apparatus in which a thermocouple is disposed in a grill case has also been proposed (see, for example, Patent Document 1).
JP-A-9-303765 (page 3, FIG. 3) JP 2004-121270 A

  Although the grill device described in Patent Document 1 uses a thermocouple for maintaining the opening of the safety valve, it does not have a function of determining the timing for stopping the heating source in accordance with the relationship between the amount of heating and the cooked food. In particular, since there is a high possibility of ignition when the amount of food is small, a function for preventing ignition when there is a small amount of food has been desired. Therefore, the grill device shown in Patent Document 2 has been developed.

  In this grill device, a determination range (first determination range in Patent Document 2) is set near the lower limit of the monitoring range suitable for cooking food, and the detected temperature rises from the lower limit to the upper limit of the determination range. When the time (namely, the rising time) required for this is shorter than the determination time (first determination time in Patent Document 2), that is, when the temperature rise per unit time (that is, the temperature increase rate) is very large, On the other hand, it is possible to prevent ignition even with a small amount of food by judging that the amount of food is small and stopping the heating.

  However, the grill device shown in Patent Document 2 does not take into account the high and low initial temperatures at the start of cooking. That is, when the temperature detected by the temperature sensor at the time of ignition of the gas burner of the heating source is higher than the case where the temperature rise rate is smaller, the rise time from the lower limit to the upper limit of the determination range becomes longer. Therefore, in this grill device, in order to reliably prevent ignition, the determination time when the initial temperature is high is used, and when the initial temperature is low, there is a risk of so-called “early disconnection”. there were.

  Moreover, in the grill apparatus shown in this patent document 2, the length of the elapsed time from the start of cooking was not taken into consideration. That is, when the elapsed time after the ignition of the gas burner of the heating source is short, the cooked food is reduced in water due to evaporation of water due to heating and is in a state that tends to ignite. It is necessary to stop heating. Therefore, in the grill device shown in Patent Document 2, in order to reliably prevent ignition, the determination time when the elapsed time after ignition is long is used, and the same applies when the elapsed time after ignition is short. There was a risk of “early out”.

  The present invention has been invented in view of the above-mentioned conventional problems, and the object of the present invention is to take a small amount of food into consideration in consideration of the initial temperature at the start of cooking and the elapsed time from the start of cooking. It is an object of the present invention to provide a grill device that reduces the possibility of ignition.

In order to solve the above-mentioned problem, according to claim 1, the heating source for heating the food in the grill case, the temperature sensor for detecting the temperature in the grill case, and the temperature detected by the temperature sensor rise. A temperature-time measurement unit for obtaining a time required for the detection temperature to rise from the lower limit to the upper limit of the determination range defined in the period, and a time obtained in the temperature-time measurement unit is shorter than a threshold defined for the determination range And a determination unit for instructing to stop heating by the heating source, the threshold value is ΔT, the temperature detected by the temperature sensor when ignited by the heating source is TH ₀ , the temperature detected by the current temperature sensor is TH, and the heating source When the elapsed time from ignition is t and A, B, C, α, β, and γ are fixed coefficients, the threshold ΔT is ΔT = A × (TH ₀ −α) + B × (TH−β) + C X (t- )
And the determination unit stops the heating by the heating source when the number of times that the time required to rise from the lower limit to the upper limit of the determination range in the temperature-time measurement unit is shorter than the threshold reaches a specified number. It is characterized by instructing.

  With such a configuration, it is possible to prevent ignition even with a small amount of food, and it is possible to appropriately set the threshold according to the initial temperature and the elapsed time from the start of cooking. Is.

  The invention according to claim 2 is the invention according to claim 1, wherein, in the temperature-time measurement unit, when the detected temperature decreases by a specified falling temperature or more, the temperature before the decrease or the temperature before the decrease. Also, the time measurement is stopped until the temperature reaches a predetermined high temperature.

  With such a configuration, when the detected temperature decreases, it is determined that the grill case has been opened, and a sudden rise in the detected temperature until the grill case closes and returns to the original temperature is mistaken as ignition and heating is performed. Stopping can be prevented.

  In the present invention, it is possible to prevent ignition even with a small amount of food, and it is possible to appropriately set a threshold according to the initial temperature and the elapsed time from the start of cooking. In spite of the fact that the detected rise time is less than the threshold judgment time, so-called “early interruption” occurs, or the temperature rise rate is greatly increased due to abnormalities. It is possible to prevent the fact that no abnormality is detected despite the short period of time.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  In the present embodiment, as shown in FIG. 1, a gas burner for burning a fuel gas such as city gas is provided as a heating source 21 in the grill case 20, and an appliance plug is provided in the fuel gas supply path to the heating source 21. 22 and a safety valve 23 comprising a solenoid valve. The grill device described in this embodiment is used for grilling raw fish or dried fish, and is assumed to be attached to a gas range, but is used as an independent instrument regardless of the gas range. It may be a thing. An ignition device 24 that ignites the heating source 21 and a temperature sensor 25 that detects the internal temperature of the grill case 20 are disposed in the grill case 20. A thermistor is used as the temperature sensor 25.

  The temperature detected by the temperature sensor 25 is input to the control device 10 including a microcomputer (hereinafter referred to as “microcomputer”). The controller 10 receives not only the temperature detected by the temperature sensor 25 but also the open / closed state of the appliance plug 22. Further, the control device 10 controls the safety valve 23 and the ignition device 24 according to the temperature detected by the temperature sensor 25 and the open / close state of the appliance plug 22. That is, the control device 10 includes an ignition / fire extinguishing control unit 11 as a control unit to which the open / close state of the instrument plug 22 and the temperature detected by the temperature sensor 25 are input, and the opening operation of the instrument plug 22 is controlled by the ignition / extinguishing control unit 11. Is detected, the safety valve 23 is opened and the ignition device 24 is activated to ignite the heating source 21. If the temperature detected by the temperature sensor 25 is equal to or higher than the ignition detection level, the ignition / fire extinguishing control unit 11 determines that the heating source 21 has ignited and keeps the safety valve 23 open. When the supply of the fuel gas to the heating source 21 is shut off by the closing operation of the instrument plug 22, the ignition / extinguishment control unit 11 closes the safety valve 23.

  By the way, in this embodiment, the heating state of the food in the grill case 20 is determined by monitoring the temperature detected by the temperature sensor 25. When the possibility of the food being ignited is high, the ignition / extinguishment control unit 11 On the other hand, a heating stop signal is given as an instruction to close the safety valve 23. That is, the temperature detected by the temperature sensor 25 is input to the temperature-time measuring unit 12 provided in the control device 10 and is in a constant temperature increment (within this embodiment, in the range of 141 to 260 ° C.). In this embodiment, the detection temperature rise time is measured every 1K). Further, the temperature-time measuring unit 12 defines a later-described determination range, and the time required for the detected temperature to rise from the lower limit to the upper limit of the determination range is obtained by accumulating the rising time of the constant temperature increment. Ask. However, when the detected temperature is higher than the high cut temperature (261 ° C. in the present embodiment) set as the temperature exceeding the monitoring range, the temperature-time measuring unit 12 does not perform time measurement at the temperature-time measuring unit 12. The heating source 21 is extinguished by giving a heating stop signal to the ignition / extinguishing control unit 11 from the determination unit 13 provided in the subsequent stage.

  The time obtained by the temperature-time measuring unit 12 is transferred to the determining unit 13, and the determining unit 13 compares the time passed from the temperature-time measuring unit 12 with a threshold value to be described later. Here, when the delivered time is shorter than the threshold value, it indicates that the internal temperature of the grill case 21 is rapidly rising. Therefore, it is determined that there is a high possibility of ignition of the cooked product, and ignition / extinguishing is performed. A heating stop signal is given to the control unit 11, the safety valve 23 is closed, and heating by the heating source 21 is stopped.

Hereinafter, a procedure for generating a heating stop signal based on the temperature detected by the temperature sensor 25 will be described in detail with reference to FIG. As shown in FIG. 2, the instrument plug 22 is opened (S1), and the counter 13a provided in the determination unit 13 is reset to 0 (S2). When the ignition / extinguishment control unit 11 confirms the completion of the ignition process of the heating source 21 within a predetermined time based on the temperature detected by the temperature sensor 25 (S3), the safety valve 23 is kept open, and the temperature sensor at this point (ignition point) the detected temperature TH ₀ (not shown) timer provided to the determination unit 13 stores in a memory (not shown) by starting the counting of the ignition time according to (S4). If the temperature detected by the temperature sensor 25 does not exceed the high cut temperature (here, 261 ° C.) (S5), the temperature detected by the temperature sensor 25 is given to the temperature-time measuring unit 12, and the following processing is performed. Here, when the end of the ignition process is not confirmed within a predetermined time after the appliance plug 22 is opened, or when the detected temperature is equal to or higher than the high cut temperature, the safety valve 23 is closed through the ignition / fire extinguishing control unit 11, and the heating source 21. Is extinguished (S11).

  When a temperature detected by the temperature sensor 25 is given to the temperature-time measuring unit 12, it is determined whether or not the detected temperature has reached a monitoring range that requires monitoring of the ignition of the food (S6). In other words, in the present embodiment, the monitoring range is set to 141 to 260 ° C., and when the detected temperature reaches 141 ° C., the temperature-time measuring unit 12 detects the detected temperature every constant temperature increment (for example, 1 K increment). Measure the time for the to rise. When the detected temperature is within the monitoring range of 141 to 260 ° C., it is determined whether or not the detected temperature is increasing (S7), and the case where the detected temperature is decreasing will be described later.

  When the detected temperature rises within a monitoring range of 141 to 260 ° C., the temperature-time measuring unit 12 determines a predetermined temperature range (12K in this embodiment) for each constant temperature increment (for example, 1K increments). Set the range. In other words, when the detected temperature reaches 141 ° C., or when the initial temperature of the detected temperature is 141 ° C. or higher, the time required to increase the temperature within a predetermined temperature range (12K) is measured in 1K increments from the ignition time. . That is, the determination range is 141 to 153 ° C, 142 to 154 ° C, ... 248 to 260 ° C. When the time required for the increase from the lower limit to the upper limit in each determination range set in this way is obtained, the determination unit 13 determines whether or not the obtained time is equal to or less than a determination time set as a threshold described later. If it is less than the determination time as the threshold (S8), it is determined that there is a possibility of ignition in the cooked food, and the counter 13a provided in the determination unit 13 is incremented by 20 (S9). When the count value counted by the counter 13a reaches a specified value (100 in this case) (S10), it is determined that there is a possibility that the cooked product will ignite, and heating is stopped (S11). In other words, when the value is not incremented elsewhere, the number of times that the time determined by the determination unit 13 is equal to or less than the determination time as the threshold reaches five times, whereby the heating is stopped. If the count value is 99 or less, the process returns to step S5 to continue monitoring the change in the detected temperature. The number of times is not limited to five, and a number of times of about 2 to 10 is mainly cited.

The operation described above is performed during a period in which the temperature detected by the temperature sensor 25 increases. However, when the food is put into the grill case 20 or when the degree of cooking of the food is checked, the door of the grill case 20 is used. Since the door is opened, the internal temperature of the grill case 20 is temporarily lowered. As described above, when the internal temperature of the grill case 20 decreases, the temperature detected by the temperature sensor 25 may suddenly increase when the door is closed again. As a result, it is determined that the food is ignited, and the heating source The heating of 21 may stop. Therefore, the temperature-time measuring unit 12 holds the count value of the counter 13a provided in the determination unit 13 when the detected temperature decreases by a specified decrease temperature (here, 1K) or more (S12), and a predetermined temperature range. (Eg, 3K) It is determined whether or not the time taken to decrease is shorter than a predetermined time (for example, 12 s) (S13). It is estimated that the grill door is opened and the grilled product is turned over, and the count value of the counter 13a provided in the determination unit 13 is reset to 0 assuming that the grilling condition is in another state (S14). Further, when the time it takes to drop a predetermined temperature range is longer than a predetermined time, it stores the Th _d (maximum value when turned to fall) temperature starts decreasing in the memory (S15), the pre-reduction The time measurement is stopped until the temperature returns or the temperature reaches a temperature higher than the temperature before the decrease (Th _d + 12K in the present embodiment) (S16). By this processing, even if the door of the grill case 20 is opened and the internal temperature is once lowered and then suddenly rises, it is prevented from being mistaken for the ignition of the cooked food. At this time, if the measurement is stopped only until the temperature returns to the temperature before the decrease rather than reaching the temperature that is higher than the temperature before the decrease (12K), the grill case will return to the temperature before the decrease. Since the temperature inside 20 is not stable and the rate of temperature increase is detected to be larger than the original temperature, measurement is performed when the temperature inside grill case 20 reaches a temperature that is higher than the temperature before the temperature is lowered by a predetermined temperature. It is preferable to return to.

  Next, the threshold value will be described. As for the threshold value, a fixed value is used for the threshold value as in the past, or only the detection value by the current (latest) temperature sensor is not taken into consideration. In the present invention, the detection value by the current temperature sensor is considered In addition, it is characterized in that it is calculated in consideration of the level of the initial temperature at the start of cooking and the elapsed time from the start of cooking.

The threshold is ΔT (s), the initial temperature at the start of cooking, that is, the temperature detected by the temperature sensor when ignited by a heating source, TH ₀ (° C.), the temperature detected by the current temperature sensor is TH (° C.), and the cooking start or heating Let t (s) be the time elapsed since ignition at the source, and A (s / K), B (s / K), C (s / s), α (° C), β (° C), γ (s ) Is a fixed coefficient, the threshold ΔT is
ΔT = A × (TH ₀ −α) + B × (TH−β) + C × (t−γ) (Formula 1)
Is calculated as follows.

  The fixed coefficients A, B, C, α, β, and γ are, for example, values shown in Table 1, and are empirically determined to be arbitrary values according to various conditions.

In this case, for example, assuming that the initial temperature TH ₀ at the start of cooking is 20 ° C., the detected temperature TH detected by the current temperature sensor is 200 ° C., and the elapsed time t from the start of cooking is 1200 s, ΔT = 120 (s).

  As described above, the higher the initial temperature at the start of cooking, the greater the amount of heat released, the smaller the difference between the amount of heat and the amount of heat released, the lower the rate of temperature rise and the longer the rise time. The threshold value that is suitable when the temperature is high is longer than the threshold value that is suitable when the temperature is low. The so-called “early cut” occurs when the rise time is less than the threshold determination time and heating is stopped, and when a suitable threshold is used as the threshold when the initial temperature is low, In this case, although the temperature rise rate is large and the rise time is short, the rise time is not less than the determination time that is the threshold value, and no abnormality is detected. However, as described above, the threshold value is set according to the initial temperature. Make it different In, in which the problem is solved.

  Also, the longer the elapsed time from the start of cooking, the easier it is to ignite due to evaporation of moisture, and it is necessary to stop heating at a lower rate of temperature rise, so the elapsed time from the start of cooking is longer If the threshold value is longer than the threshold value suitable for a short time, and the threshold value suitable for a long time elapsed from the start of cooking is used as the threshold value, it is normal when the elapsed time from the start of cooking is short. However, a threshold value that is suitable when the detected rise time is equal to or less than the determination time, which is a threshold value, and “premature cut” occurs in which heating is stopped, and the elapsed time from the start of cooking is short as the threshold value. When the elapsed time from the start of cooking is long, the temperature rise rate is large and the rise time is short. Becomes bets, but by varying the threshold according to the time elapsed from the start of cooking as described above, in which the problem is solved.

It is a block block diagram which shows embodiment of this invention. It is operation | movement explanatory drawing same as the above.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Control apparatus 11 Ignition / extinguishment control part 12 Temperature-time measurement part 13 Judgment part 13a Counter 20 Grill case 21 Heat source 22 Instrument plug 23 Safety valve 24 Ignition apparatus 25 Temperature sensor

Claims (2)

A heating source that heats the food in the grill case, a temperature sensor that detects the temperature in the grill case, and a temperature that is detected by the temperature sensor rises from a lower limit to an upper limit of the determination range that is defined in the period during which the temperature increases. A temperature-time measurement unit for obtaining a time required for the temperature, and a determination unit for instructing to stop heating by a heating source when the time obtained in the temperature-time measurement unit is shorter than a threshold value defined for the determination range, The threshold value is ΔT, the detected temperature by the temperature sensor when ignited by the heating source is TH ₀ , the detected temperature by the current temperature sensor is TH, and the elapsed time from the ignited by the heating source is t, and A, B, C, When α, β, and γ are fixed coefficients, the threshold ΔT is ΔT = A × (TH ₀ −α) + B × (TH−β) + C × (t−γ)
And the determination unit stops the heating by the heating source when the number of times that the time required to rise from the lower limit to the upper limit of the determination range in the temperature-time measurement unit is shorter than the threshold reaches a specified number. A grill device characterized by indicating.   The temperature-time measurement unit is characterized in that when the detected temperature is lowered by a specified falling temperature or more, the time measurement is stopped until the temperature reaches a temperature before the decrease or a temperature higher than the temperature before the decrease by a predetermined temperature. The grill device according to claim 1.

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