Flyer

Abstract

To appropriately cook an object to be cooked by preventing overshooting of the temperature of cooking oil.SOLUTION: A storage part of a burner controller of a fryer stores a cooking temperature zone V composed of a permissible upper limit temperature T1 and a permissible lower limit temperature T2 for each elapsed time set beforehand, and predetermined control lines L1-L3 set by variables of the time elapsed from the start of cooking and a predetermined target temperature on the basis of the cooking temperature zone V. The control lines L1-L3 are set in a first control region E1 lower than the permissible lower limit temperature T2 in an initial stage of the cooking, set in a second control region E2 in the cooking temperature zone V and in the lower half of the cooking temperature zone V in the intermediate stage of the cooking, and set in a third control region E3 in the cooking temperature zone V and in the upper half of the cooking temperature zone V in the ending stage of the cooking.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a commercial fryer that heats cooking oil in an oil tank and puts the object to be cooked into the oil tank for heat cooking.

Background Art

[0002] As disclosed in Patent Document 1, a fryer has an oil tank for storing cooking oil, heating means such as a burner or a pulse combustor for heating the cooking oil, and control means for controlling the heating means. When an object to be cooked such as potatoes is put into the oil tank, the control means controls the heating means to perform heat cooking. A control line is set in the control means such that the detected temperature of the cooking oil obtained from temperature detection means such as a thermistor changes in a continuous line or an intermittent stepped line depending on the elapsed time from the start of cooking and the target temperature. This control line is determined based on a cooking temperature range surrounded by an allowable upper limit temperature and an allowable lower limit temperature for each preset elapsed time for heating and cooking the object to be cooked. When cooking is started, the control means controls the heating means (for example, ON / OFF control of a pulse combustor) so that the detected temperature of the cooking oil changes along the control line within the cooking temperature range.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in such a fryer, when cooking with a small amount of cooking oil, the retained heat quantity of the cooking oil becomes smaller accordingly. Therefore, due to the input of the object to be cooked, the heat of vaporization generated during cooking, the amount of heat applied by the heating means, etc., the temperature tends to change more sensitively and with a larger amplitude. In addition, the cooking temperature range is set based on the value measured by inserting a thermometer into the central part of the cooking oil in which the object to be cooked is directly heated by cooking, that is, the value affected by the latent heat of vaporization of the object to be cooked, etc. On the other hand, the detected temperature is the temperature detected from a thermistor or the like provided on the wall surface of the oil tank that is less affected by the object to be cooked, and there is variation depending on the detection position and detection environment. Therefore, it is inevitable that a deviation occurs between the cooking temperature range and the detected temperature, and simply performing ON / OFF control so that the detected temperature does not exceed the cooking temperature range will increase the deviation between the actual temperature and the cooking temperature range.

[0005] Then, when cooking a frozen potato at about -20°C as the object to be cooked, immediately after the object to be cooked is put in, a large amount of the heat retained by the cooking oil is taken away by the object to be cooked, and latent heat of vaporization is generated as the water content retained by the object to be cooked evaporates. Therefore, an undershoot where the temperature of the object to be cooked is much lower than the cooking temperature range is likely to occur. On the other hand, if the control line at the initial stage of cooking is inadvertently set to a high temperature and the heating means is likely to be in the ON state, even if the temperature around the object to be cooked shows an upward trend, a certain time lag will occur until the situation is transmitted to a thermistor or the like provided on the wall surface. Therefore, the time during which unnecessary heat is applied continues, and there is a risk that excessive heat is applied to the object to be cooked and the finish is poor.

[0006] Therefore, an object of the present disclosure is to provide a fryer that can prevent the actually measured temperature of the object to be cooked from deviating from the cooking temperature range and can maintain a good finish of the object to be cooked even when cooking the object to be cooked with a small amount of cooking oil.

Means for Solving the Problems

[0007] In order to achieve the above object, the present disclosure includes an oil tank capable of accommodating cooking oil, temperature detection means for detecting the temperature of the cooking oil, heating means provided in the oil tank that operates in an ON / OFF manner to heat the cooking oil, Control means for controlling the heating means, comprising a timer and a memory unit, In the memory unit, so as not to overheat the object to be cooked Pre-set change in a curve shape that shows a downward trend over time and then an upward trend The allowable upper limit temperature and pre-set so as not to underheat the object to be cooked, change in a curve shape that shows a downward trend over time and then an upward trend, and has a minimum temperature The allowable lower limit temperature, surrounded The cooking temperature range, and a predetermined control line set by variables of the elapsed time from the start of cooking and a predetermined target temperature based on the cooking temperature range are stored, The control means is a fryer that ON / OFF controls the heating means so that the detected temperature by the temperature detection means changes along the control line, The control line is set in a first control region below the allowable lower limit temperature at the initial stage of cooking, in a second control region within the cooking temperature range and in the lower half of the cooking temperature range at the middle stage of cooking, and in a third control region within the cooking temperature range and in the upper half of the cooking temperature range at the final stage of cooking. This is a characteristic. Note that the control line in the initial stage of cooking includes not only those entirely set in the first control region, but also those partially set in the second control region at a slow timing leading to the middle stage of cooking. Similarly, the control line in the final stage of cooking includes not only those entirely set in the third control region, but also those partially set in the second control region. Another aspect of the present disclosure is in the above configuration 、 The temperature of the control line in the first control region is set to a value below the allowable lower limit temperature and above the minimum temperature. This is a characteristic. Another aspect of the present disclosure is in the above configuration. In the second control region, when the allowable lower limit temperature shows an upward trend exceeding the minimum temperature, the control line is set to approach the median value between the allowable upper limit temperature and the allowable lower limit temperature as time elapses. This is a characteristic.

Advantages of the Invention

[0008] According to the present disclosure, even when cooking an object to be cooked with a small amount of cooking oil, it is possible to prevent the measured temperature of the object to be cooked from deviating from the cooking temperature range and to maintain the finish of the object to be cooked well. According to another aspect of the present disclosure, in addition to the above effects 、 Since the temperature of the control line in the first control region is set to a value that is lower than the allowable lower limit temperature and higher than the minimum temperature, overheating by the heating means can be suppressed, preventing undershoot from occurring. According to another aspect of the present disclosure, in addition to the above effects, when the allowable lower limit temperature of the control line in the second control region shows an upward trend exceeding the minimum temperature, it approaches the median value between the allowable upper limit temperature and the allowable lower limit temperature over time, so a rapid increase in the measured temperature can be suppressed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. FIG. 1 is a perspective view showing an example of a fryer, and FIG. 2 is a schematic diagram of the fryer. This fryer 1 includes a pair of left and right oil tanks 3, 3 at the upper part inside the vessel body 2. At the bottom of each oil tank 3, a pair of left and right pulse burners 4, 4 as heating means are respectively provided. Each pulse burner 4 has a combustion chamber 5 provided on the front inner wall of the oil tank 3 and a tail pipe 6 connected to the combustion chamber 5 and snaking through the oil tank 3. Since the configurations of each oil tank 3 and its combustion system and exhaust system are the same on the left and right, the following mainly describes the oil tank 3 on the left side of FIG. 1.

[0011] The oil tank 3 has a first cooking section 7 and a second cooking section 8. The first cooking section 7 is formed above the pulse combustor 4 and has a rectangular tube shape with a constant opening area in the vertical direction. The second cooking section 8 is located above the first cooking section 7 and is formed in an inverted taper shape that expands in the front-back and left-right directions as it goes upward from the upper end of the first cooking section 7. The upper end up to the second cooking section 8 serves as the storage section for the cooking oil. A basket 9 containing an object to be cooked such as potatoes can be inserted into the oil tank 3. Above the pulse combustors 4, 4, a net 10 for receiving the basket 9 is provided. Near the upper end surface of the first cooking section 7, a first oil surface temperature sensor 11 is provided. Near the upper end surface of the second cooking section 8, a second oil surface temperature sensor 12 is provided. Near the tail pipe 6 of the pulse combustor 4 in the oil tank 3, a cooking temperature sensor 13 is provided. An electric heater 33 is provided on the lower outer peripheral surface of the oil tank 3.

[0012] Behind the oil tank 3 and above the body 2, an oil replenishing tank 14 for storing the cooking oil is provided. On the lower surface of the oil replenishing tank 14, an oil replenishing pipe 15 connected to the second cooking section 8 at the rear surface of the oil tank 3 is connected. An oil replenishing valve 16 that is opened and closed manually is provided on the oil replenishing pipe 15. An oil replenishing temperature sensor 17 for detecting the temperature of the stored cooking oil is provided in the oil replenishing tank 14. An overflow section 18 is provided on the front surface of the oil replenishing tank 14. The overflow section 18 is formed by a pipe connected to the front surface of the oil replenishing tank 14, a flow path formed vertically on the front surface of the oil replenishing tank 14, etc. The upper end of the overflow section 18 is connected to an opening formed in the upper part of the front surface of the oil replenishing tank 14 and hangs down, and the lower end of the overflow section 18 is connected to the inner surface of the rear part in the oil tank 3 via an outlet 19. Therefore, when the cooking oil in the oil replenishing tank 14 exceeds the lower edge of the opening, the overflowed cooking oil flows down into the oil tank 3 along the inner surface of the rear part of the oil tank 3 from the outlet 19.

[0013] An air chamber 20 is provided outside the front side of the oil tank 3. Inside the air chamber 20, a mixing chamber (not shown) communicating with the combustion chamber 5 is provided. A gas conduit 21 equipped with a gas solenoid valve 22 is connected to the mixing chamber, and fuel gas is supplied. Also, an air supply pipe 23 is connected to the mixing chamber. The air supply pipe 23 is connected to a fan 24 provided at the lower part of the vessel body 2, and combustion air is supplied. The tail pipes 6, 6 of the pulse combustors 4, 4 are arranged in a meandering shape at the lower part of the oil tank 3 and then connected to exhaust pipes 25, 25 drawn out from the air chamber 20. These exhaust pipes 25, 25 have mufflers 26, 26 arranged at the rear part of the vessel body 2. The mufflers 26, 26 are arranged upward in a state of contacting the rear surface of the fuel increasing tank 14, enabling the discharge of combustion exhaust gas. The fuel increasing tank 14 and the mufflers 26, 26 are covered with an exhaust pipe cover 27 provided on the vessel body 2. Protective covers 28 are provided on the front surfaces of the left and right exhaust pipe covers 27, 27. Basket hangers 29, 29 for suspending and supporting the baskets 9, 9 are fixed to the protective cover 28. The outlet 19 of the overflow part 18 is provided below the basket hanger 29.

[0014] A filtering tank 30 equipped with a filter at the bottom is provided at the bottom of the vessel body 2. An oil discharge pipe 31 is connected to the bottom of the oil tank 3, and the cooking oil in the oil tank 3 can be discharged to the filtering tank 30 through the oil discharge pipe 31. An oil discharge valve 32 that opens and closes manually is provided on the oil discharge pipe 31. A filtering pump 35 is provided at the lower part of the vessel body 2. The suction side of the filtering pump 35 is connected to the bottom of the filtering tank 30 through a suction pipe 36. The discharge side of the filtering pump 35 branches into a first oil supply pipe 37 and a second oil supply pipe 38. The first oil supply pipe 37 is connected to the fuel increasing pipe 15 upstream of the fuel increasing valve 16. A first oil supply valve 39 that opens and closes manually is provided on the first oil supply pipe 37. The second oil supply pipe 38 is connected to the lower part of the oil tank 3. A second oil supply valve 40 that opens and closes manually is provided on the second oil supply pipe 38.

[0015] Below the oil tank 3, an additional oil tank 45 using a one-bucket can is provided. The additional oil tank 45 is installed on a mounting base 46 provided on the container body 2. The mounting base 46 is provided with a heat preservation heater 47 for heating the additional oil tank 45 and a tank temperature sensor 48 for detecting the temperature of the additional oil tank 45. The lower end of an additional oil pipe 49 is inserted into the additional oil tank 45. The upper end of the additional oil pipe 49 is connected to the oil tank 3 above the second cooking unit 8. The additional oil pipe 49 is provided with an additional oil pump 50 and an additional oil solenoid valve 51 from the upstream side.

[0016] A fry controller 60 is provided at the upper front part of the container body 2. The fry controller 60 is provided with an operation panel 61. As shown in FIG. 3, the operation panel 61 is provided with a power switch 62, a plurality of cooking buttons 63, 63 ···, display units 64, 64 such as a selected cooking mode and a maintenance menu, a mode selection button 65 for selecting a cooking mode, and rated quantity display lamps 66A, 66B for displaying a rated quantity. The rated quantity display lamp 66A corresponds to the first rated quantity, and the rated quantity display lamp 66B corresponds to the second rated quantity respectively. A burner controller 70 is provided at the lower part of the container body 2. The burner controller 70 is provided with a timer 71 and a storage unit 72, and performs ON / OFF control of the pulse burner 4 according to the cooking mode instructed from the fry controller 60 to cook the object to be cooked such as potatoes. Detection signals such as the first and second oil surface temperature sensors 11, 12, a cooking temperature sensor 13, an oil increasing temperature sensor 17, and a tank temperature sensor 48 are input to the burner controller 70. Based on these detection signals and instructions from the operation panel 61, the burner controller 70 controls the pulse burner 4, the gas solenoid valve 22, the fan 24, the electric heater 33, the filtering pump 35, the heat preservation heater 47, the additional oil pump 50, the additional oil solenoid valve 51, etc.

[0017] In the fryer 1 configured as described above, the amount of the object to be cooked at one time is defined in two types: a predetermined first rated amount and a second rated amount greater than the first rated amount, and it is possible to cook in a first cooking mode corresponding to the first rated amount and a second cooking mode corresponding to the second rated amount, respectively. In the oil replenishing tank 14, cooking oil in a full state (oil replenishment) is stored. When the burner controller 70 detects that the operator turns on the power switch 62 of the operation panel 61, the burner controller 70 rotates the fan 24 for a predetermined time to supply air, and then intermittently burns the mixed gas in the combustion chamber 5 to turn the pulse burner 4 on and off. That is, the mixed gas is ignited in the combustion chamber 5 and explosively burned in the combustion chamber 5, and the combustion exhaust gas is forcibly discharged to the tail pipe 6 due to the pressure increase in the combustion chamber 5 accompanying the combustion. Then, the fuel gas and the combustion air are inhaled into the combustion chamber 5 that becomes negative pressure due to the discharge of the combustion exhaust gas. By repeating this on / off operation, the cooking oil stored in the oil tank 3 is heated.

[0018] Before starting cooking, the burner controller 70 monitors the detected temperature obtained from the cooking temperature sensor 13, and executes a standby mode in which the pulse burner 4 is turned on and off to maintain the detected temperature at a predetermined standby temperature (for example, 160°C). During the execution of the standby mode, the fry controller 60 notifies the operator by outputting a "Cooking OK" display on the display unit 64 of the operation panel 61. Then, the operator selects either the first or second cooking mode with the mode selection button 65, puts the basket containing the object to be cooked in the corresponding rated amount into the oil tank 3, and presses the cooking start button (here, the leftmost cooking button 63). Then, the burner controller 70 cooks the object to be cooked with the cooking time and the calorific value of the pulse burner 4 preset corresponding to the rated amounts, respectively.

[0019] In the storage unit 72 of the burner controller 70, as shown by the dashed line in Fig. 4, a cooking temperature range V surrounded by the allowable upper limit temperature T1 and the allowable lower limit temperature T2 that change with each elapsed time is set. This cooking temperature range V becomes a curve that shows a downward trend and then an upward trend over time. The allowable lower limit temperature T2 has a minimum temperature Tmin at the inversion position between the downward trend and the upward trend. Based on this cooking temperature range V, in the storage unit 72, intermittent control lines L1 to L3 (shown by solid lines) are set for each cooking mode, where the target temperature at the start of cooking changes stepwise according to the elapsed time from the start of cooking and the target temperature. However, in each cooking mode, the control line L1 at the initial stage of cooking from the start time t0 of cooking to the first elapsed time t1 is set within the first control region E1 that is lower than the allowable lower limit temperature T2 of the cooking temperature range V. However, the control line L1 is set to exceed the minimum temperature Tmin and, immediately before the first elapsed time t1, a part of it is within the second control region E2 that is the lower half of the cooking temperature range V. Next, the control lines L2, L2... in the middle stage of cooking from the first elapsed time t1 to the second elapsed time t2 are each set within the cooking temperature range V and within the second control region E2 that is the lower half of the cooking temperature range V. In addition, the control line L2 after the allowable lower limit temperature T2 exceeds the minimum temperature Tmin and shows an upward trend is set to gradually approach the median value Tmid between the allowable upper limit temperature T1 and the allowable lower limit temperature T2 over time. Then, the control line L3 at the final stage of cooking from the second elapsed time t2 to the third elapsed time t3 when cooking ends is set within the cooking temperature range V and within the third control region E3 that is the upper half of the cooking temperature range V. However, the control line L3 is set so that a part of it is within the second control region E2 immediately before the third elapsed time t3.

[0020] The burner controller 70 controls the ON / OFF of the pulse combustor 4 so that the detected temperature is maintained along the control lines L1, L2, L3 corresponding to the selected cooking mode from the start time t0 of cooking. Therefore, at the initial stage of cooking, since it is ON / OFF controlled based on the control line L1 in the first control region E1, excessive heat is not applied to the cooking oil, and overshoot can be suppressed. At this initial stage of cooking, bubbles are generated from the object to be cooked, and the cooking oil is cooled by the heat of vaporization, so the temperature of the cooking oil does not easily rise. However, as cooking progresses, the number of bubbles generated decreases, so the temperature of the cooking oil tends to rise. Therefore, in the middle stage of cooking, since the control line L2 is set in the second control region E2 in the lower half of the cooking temperature range V, it is possible to suppress the cooking oil from rising all at once and prevent overshoot in the middle stage of cooking.

[0021] And at the final stage of cooking, since the control line L3 is set in the third control region E3 in the upper half of the cooking temperature range V, the temperature of the cooking oil at the end of cooking can be made close to the temperature at the start of cooking. Therefore, it is possible to quickly respond to the heating and cooking of the next object to be cooked. Note that at the final stage of cooking, the heating and cooking of the object to be cooked has progressed considerably and the number of generated bubbles has decreased, so the influence of the heat of vaporization is small, and the detected temperature and the actual temperature of the cooking oil around the object to be cooked are in a close state. Therefore, even if the control line L3 is set in the third control region E3 in the upper half of the cooking temperature range V, there is little risk that the temperature of the cooking oil will suddenly exceed the cooking temperature range V. In this way, by ON / OFF controlling the pulse burner 4 along each control line L1 to L3, the actual temperature (measured temperature) T of the cooking oil will change within the cooking temperature range V as shown by the dotted line. When the time is up at the third elapsed time t3, the fry controller 60 sounds an alarm to notify the end of cooking. Therefore, the cook pulls up the basket 9 from the oil tank 3. When continuing cooking, if the object to be cooked is put in and the cooking start button is pressed, the same control will be repeated.

[0022] On the other hand, during operation in each cooking mode, the burner controller 70 monitors the detected temperature obtained from the tank temperature sensor 48 and ON / OFF controls the heat preservation heater 47 so that a predetermined heat preservation temperature is maintained in the make-up oil tank 45. When the first and second oil level sensors 11 and 12 detect a decrease in the cooking oil required in any of the cooking modes or reach a predetermined number of cooking times, the topping-up pump 50 is driven to open the topping-up solenoid valve 51. Then, the liquefied cooking oil in the topping-up tank 45 is directly supplied to the oil tank 3 through the topping-up oil pipe 49.

[0023] As described above, the fryer 1 of the above configuration includes an oil tank 3 capable of storing cooking oil, a cooking temperature sensor 13 (temperature detection means) for detecting the temperature of the cooking oil, a pulse burner 4 (heating means) provided in the oil tank 3 and operating in an ON / OFF manner to heat the cooking oil, and a burner controller 70 (control means) including a timer 71 and a storage unit 72 for controlling the pulse burner 4. Further, in the storage unit 72, a cooking temperature range V composed of a preset allowable upper limit temperature T1 and an allowable lower limit temperature T2 for each elapsed time, and predetermined control lines L1 to L3 set as variables of the elapsed time from the start of cooking and a predetermined target temperature based on the cooking temperature range V are stored. Furthermore, the burner controller 70 performs ON / OFF control of the pulse burner 4 so that the detected temperature by the cooking temperature sensor 13 changes along the control lines L1 to L3. The control lines L1 to L3 are set in a first control region E1 below the allowable lower limit temperature T2 at the initial stage of cooking, in a second control region E2 within the cooking temperature range V and in the lower half of the cooking temperature range V at the middle stage of cooking, and in a third control region E3 within the cooking temperature range V and in the upper half of the cooking temperature range V at the final stage of cooking. According to this configuration, even when cooking the object to be cooked with a small amount of cooking oil, it is possible to prevent the actually measured temperature T of the object to be cooked from deviating from the cooking temperature range V and to maintain a good finish of the object to be cooked.

[0024] In particular, the allowable lower limit temperature T2 is defined as a curve having a minimum temperature Tmin after showing a downward trend and then an upward trend over time, and the temperature of the control line L1 in the first control region E1 is set to a value below the allowable lower limit temperature T2 and above the minimum temperature Tmin. Therefore, it is possible to prevent the heating by the pulse combustor 4 from being excessively suppressed and an undershoot from occurring. Further, when the control line L2 in the second control region E2 shows an upward trend with the allowable lower limit temperature T2 exceeding the minimum temperature Tmin, it is set to approach the median value Tmid between the allowable upper limit temperature T1 and the allowable lower limit temperature T2 over time. Therefore, a rapid rise in the measured temperature T can be suppressed.

[0025] Hereinafter, modified examples will be described. The cooking temperature range and the control line are not limited to the above form and can be changed as appropriate. For example, the cooking temperature range may be linear, and the control line is not limited to the intermittent linear form of the above form, and may be an intermittent curved form, a continuous curved form, a linear form, or the like. The lengths of the early cooking stage, the middle cooking stage, and the final cooking stage are also not limited to the above form. In the above form, a part of the control line in the early cooking stage is set within the second control region, but all of the control line may be set within the first control region. Similarly, in the above form, a part of the control line in the final cooking stage is set within the second control region, but all of the control line may be set within the third control region. In the above form, the first and second cooking modes can be executed, but the cooking mode may be single, or three or more cooking modes may be executable. In any case, the setting of the control line of the present disclosure is possible.

[0026] The fryer is not limited to one in which a fry controller and a burner controller are provided separately, and may be one provided with one controller having both functions of the fry controller and the burner controller. The heating means may be formed only by a pulse combustor, or may be formed only by an electric heater. Further, the heating means may be formed only by a gas burner provided outside the oil tank. Furthermore, the heating means may be formed by a combination other than the combination of a pulse combustor and an electric heater. In the above form, a pair of left and right oil tanks are provided, but the number of oil tanks may be one, or conversely, three or more. The present disclosure is also applicable to a pressure fryer that closes the opening of an oil tank with a lid.

Explanation of Reference Numerals

[0027] 1 ··· Fryer, 2 ··· Body, 3 ··· Oil tank, 4 ··· Pulse combustor, 5 ··· Combustion chamber, 6 ··· Tail pipe, 7 ··· First cooking section, 8 ··· Second cooking section, 9 ··· Basket, 11 ··· First oil level temperature sensor, 12 ··· Second oil level temperature sensor, 13 ··· Cooking temperature sensor, 14 ··· Oil replenishment tank, 15 ··· Oil replenishment pipe, 16 ··· Oil replenishment valve, 18 ··· Overflow section, 22 ··· Gas solenoid valve, 30 ··· Filtering tank, 35 ··· Filtering pump, 37 ··· First fuel supply pipe, 38 ··· Second fuel supply pipe, 39 ··· First fuel supply valve, 40 ··· Second fuel supply valve, 60 ··· Fry controller, 61 ··· Operation panel, 62 ··· Power switch, 63 ··· Cooking button, 64 ··· Display section, 65 ··· Mode selection button, 66A, 66B ··· Rated quantity display lamps, 70 ··· Burner controller, 71 ··· Timer, 72 ··· Memory section, V ··· Cooking temperature range, T1 ··· Allowable upper limit temperature, T2 ··· Allowable lower limit temperature, Tmid ··· Median value, Tmin ··· Minimum temperature, L1 to L3 ··· Control lines, E1 ··· First control region, E2 ··· Second control region, E3 ··· Third control region.

Claims

1. An oil tank capable of accommodating cooking oil, temperature detection means for detecting the temperature of the cooking oil, heating means provided in the oil tank and operating in an ON / OFF manner to heat the cooking oil, control means including a timer and a memory unit for controlling the heating means, in the memory unit, a permissible upper limit temperature that is preset so as not to overheat the object to be cooked, and changes in a curve shape showing a downward trend and then an upward trend over time; and a cooking temperature range surrounded by a permissible lower limit temperature that is preset so as not to underheat the object to be cooked, changes in a curve shape showing a downward trend and then an upward trend over time, and has a minimum temperature, and a predetermined control line set by variables of the elapsed time from the start of cooking and a predetermined target temperature based on the cooking temperature range are stored, the control means is a fryer that performs ON / OFF control of the heating means so that the detected temperature by the temperature detection means changes along the control line, the control line is set in a first control region below the permissible lower limit temperature at the initial stage of cooking, in a second control region within the cooking temperature range and in the lower half of the cooking temperature range at the middle stage of cooking, and in a third control region within the cooking temperature range and in the upper half of the cooking temperature range at the final stage of cooking. A fryer characterized by this.

2. The temperature of the control line in the first control region is set to a value that is lower than the permissible lower limit temperature and higher than the minimum temperature. The fryer according to claim 1, characterized by this.

3. When the permissible lower limit temperature shows an upward trend exceeding the minimum temperature in the second control region, the control line in the second control region is set to approach the median value between the permissible upper limit temperature and the permissible lower limit temperature over time. The fryer according to claim 2, characterized by this.

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