JP7489848B2 - Heating Cooker - Google Patents

Description

The present invention relates to a cooking device that cooks food using hot air, such as a steam convection oven, and in particular to a cooking device with a function for cleaning the cooking chamber.

The following Patent Document 1 discloses a cooking device that cooks ingredients with hot air. This cooking device includes a cooking chamber that cooks ingredients, a heater that heats the inside of the cooking chamber, a convection fan that circulates air in the cooking chamber, a steam generator that supplies steam into the cooking chamber, and a control device that controls the operation of the heater, the convection fan, and the steam generator. The control device of this cooking device includes a cooking program for automatically cooking ingredients, and when the cooking program is executed by the control device, the air in the cooking chamber is convected as hot air by the operation of the heater and the convection fan, and steam is supplied to the convecting hot air by the operation of the steam generator, and the ingredients stored in the cooking chamber are cooked by the hot air containing steam.

When food is cooked in the cooking chamber, the oil contained in the food is dispersed inside the cooking chamber along with the convection of hot air, and the oil adheres to the walls of the cooking chamber. This type of cooking device requires that the inside of the cooking chamber be kept clean at all times, and it is hygienic to clean the cooking chamber, for example, every day after use. This cooking device is equipped with a cleaning nozzle that sprays cleaning water onto the ceiling of the cooking chamber, a cleaning water passage that connects a drain outlet at the bottom of the cooking chamber to the cleaning nozzle, a tank that is installed in the cleaning water passage to temporarily store the cleaning water, and a pump that sends the cleaning water in the tank to the cleaning nozzle so that the inside of the cooking chamber can be cleaned automatically.

The control device of this cooking device has a cleaning program that automatically cleans the inside of the cooking chamber. When the cleaning program is executed by the control device, cleaning water in the tank is sent to the cleaning nozzle by the operation of the pump, and the sent cleaning water is sprayed from the cleaning nozzle into the cooking chamber. The sprayed cleaning water is heated to high temperature by the hot air circulating due to the operation of the heater and convection fan, and is splashed into the cooking chamber in this state. The splashed cleaning water returns to the tank from the drain, and the inside of the cooking chamber is cleaned by the high temperature cleaning water circulating between the tank and the cooking chamber.

JP 2019-138618 A

In the cooking device described in Patent Document 1 above, when the cleaning program is executed, cleaning water sprayed from the cleaning nozzle into the cooking chamber is heated by the hot air circulating due to the operation of the heater and the convection fan, and becomes high-temperature cleaning water, which is then scattered throughout the cooking chamber. At this time, if the convection fan is controlled to alternate between forward and reverse rotation every predetermined time, the cleaning water will be scattered throughout the cooking chamber due to the periodically changing air flow within the cooking chamber.

When the cleaning program is being executed, the cleaning water sprayed from the cleaning nozzle is scattered throughout the cooking chamber by the convection fan and then returns to the tank through the drain, but the cleaning water that has scattered throughout the cooking chamber is swirled by the air flow caused by the convection fan and returned to the tank through the drain, so it temporarily accumulates at the bottom of the cooking chamber. When the convection fan is temporarily stopped to change the direction of rotation of the convection fan, the flow of cleaning water at the bottom of the cooking chamber changes, the amount of cleaning water remaining in the cooking chamber temporarily increases, and the amount of cleaning water remaining in the tank temporarily decreases. If the pump is operated continuously in this state, air may be contained in the cleaning water that the pump draws into the tank, causing the pump to draw in cleaning water containing air, which is known as air entrapment. The present invention aims to make it less likely that the pump will draw in air together with the cleaning water when a cleaning program is executed to clean the inside of the cooking chamber of a heating cooker.

In order to solve the above problems, the present invention provides a cooking chamber for cooking ingredients, a convection fan for circulating air in the cooking chamber, a drain outlet provided at the bottom of the cooking chamber, a washing nozzle provided at the ceiling of the cooking chamber for spraying washing water, a washing water passage connecting the drain outlet and the washing nozzle, a tank provided in the washing water passage for temporarily storing washing water, a pump for sending the washing water in the tank to the washing nozzle, and a control device for controlling the operation of the convection fan and the pump, and the control device operates the pump to send the washing water in the tank to the washing nozzle and spray it from the washing nozzle into the cooking chamber, and This is a cooking device with a cleaning function for a cooking chamber, which has a cleaning program that operates a convection fan to splash the cleaning water into the cooking chamber with the convecting air, returns the splashed cleaning water to a tank through a drain outlet, and cleans the inside of the cooking chamber with the cleaning water circulating between the tank and the convection fan. The control device controls the convection fan to alternately change its rotation direction between forward and reverse at predetermined time intervals while the cleaning program is being executed, and controls the pump to temporarily stop operation when the rotation direction of the convection fan is changed.

In the cooking device configured as described above, when the cleaning program is being executed, the convection fan is controlled to alternate between forward and reverse rotation every predetermined time, and the cleaning water sprayed from the cleaning nozzle is scattered to every corner of the cooking chamber by the air convection caused by the convection fan, which alternates between forward and reverse rotation every predetermined time. The cleaning water scattered in the cooking chamber flows into the drain while swirling at the bottom of the cooking chamber due to the flow of convection air, so that the cleaning water at the bottom of the cooking chamber is given centrifugal force when swirling, and the cleaning water temporarily accumulates at the bottom of the cooking chamber. When the rotation direction of the convection fan is changed, the operation of the convection fan is temporarily stopped, and the flow of the cleaning water that flows into the drain while swirling at the bottom of the cooking chamber also changes. At this time, the amount of cleaning water remaining at the bottom of the cooking chamber temporarily increases due to the change in flow, and as a result, the amount of cleaning water returning to the tank decreases. If the cleaning water in the tank is pumped to the cleaning nozzle in this state, the pump may suck in air along with the cleaning water. In response to this, the pump is controlled to temporarily stop operation when the rotation direction of the convection fan is changed. This means that the pump temporarily stops operating when the amount of cleaning water returning to the tank is decreasing, preventing the pump from sucking in air along with the cleaning water, which is known as air entrapment.

In the cooking device configured as described above, the tank is provided with a water level sensor that detects the water level in the tank, and the control device preferably controls the pump to operate again when the water level sensor detects a water level at which no air flows into the pump after temporarily stopping the pump when the rotation direction of the convection fan is changed. When doing so, the pump is controlled to operate again only after the water level in the tank reaches a level at which no air flows into the pump, so that it is possible to reliably prevent the pump from sucking in air together with the cleaning water, a phenomenon known as air entrapment.

1 is a front view of an embodiment of a cooking device of the present invention. FIG. FIG. 2 is a front view of FIG. 1 with the door open. FIG. 2 is a longitudinal cross-sectional view taken at the center in the front-rear direction. This is a cross-sectional view taken along line A-A. 2 is a cross-sectional view taken along line AA when the partition plate and the support frame are removed. FIG. FIG. 13 is a left side view showing the machine compartment with the left panel of the housing removed. FIG. 1 is a schematic diagram of a cooking device. FIG. 2 is a block diagram of a control device. 10 is a flowchart showing control of a first cleaning program. 10 is a flowchart showing control of a steam pre-cleaning operation. 10 is a flowchart showing control of a cleaning operation. 4 is a flowchart showing control of a drying operation. FIG. 8 is a schematic diagram corresponding to FIG. 7 of an embodiment in which a water level sensor is provided in the tank. FIG. 11 is a perspective view of a drainage tray showing another embodiment.

An embodiment of the cooking device of the present invention will be described below with reference to the attached drawings. The cooking device of the present invention is called a steam convection oven, and cooks food by convection of hot air containing steam. This cooking device also has a cooking chamber cleaning function for cleaning the inside of the cooking chamber. As shown in FIG. 1, the cooking device 10 has a machine chamber 12 on the left side of the housing 11, and a cooking chamber 20 for cooking food in the part of the housing 11 excluding the machine chamber 12. As shown in FIG. 2, an opening 20a for putting in and taking out food is provided in the front part of the cooking chamber 20, and a door 13 for opening and closing the opening 20a is provided in the opening 20a. As shown in FIGS. 1 and 2, a door opening detector 13a is provided in the front part of the cooking chamber 20, and the door opening detector 13a detects whether the door 13 is closing (opening) the opening 20a.

As shown in FIG. 3, the cooking chamber 20 is for storing ingredients and cooking them. The cooking chamber 20 except for the left side is a food storage chamber 21 for storing ingredients, and the left side is a hot air generation chamber 22 for generating hot air to be sent to the food storage chamber 21. A partition plate 23 is provided on the left side of the center of the cooking chamber 20 in the left-right direction to separate the food storage chamber 21 and the hot air generation chamber 22, and the partition plate 23 separates the food storage chamber 21 and the hot air generation chamber 22 so that ventilation can be performed between them. The partition plate 23 functions as a fan cover that covers the intake side of the convection fan 26 arranged in the hot air generation chamber 22. As shown in FIG. 4, the partition plate 23 is formed with a number of intake ports 23a, and the air in the food storage chamber 21 is sent to the hot air generation chamber 22 through the intake port 23a. In addition, the partition plate 23 is attached so that a space through which air can pass is formed between the ceiling wall, bottom wall, front wall, and rear wall of the cooking chamber 20, and a ventilation passage 23b through which air passes is formed between the partition plate 23 and the ceiling wall, bottom wall, front wall, and rear wall of the cooking chamber 20, and the air in the hot air generating chamber 22 is sent to the food storage chamber 21 through the ventilation passage 23b.

As shown in Figures 2 to 4, the food storage chamber 21 of the cooking chamber 20 is provided with a pair of left and right support frames 24 that support trays called hotel pans in multiple levels vertically. The support frames 24 in this embodiment support 10 levels of trays vertically and are made by bending metal wire material. The support frames 24 are equipped with a pair of front and rear support columns 24a and rails 24b that are fixed to the front and rear support columns 24a and support the left and right edges of the trays.

3 and 5, the hot air generating chamber 22 of the cooking chamber 20 is provided with a heater 25 and a convection fan 26. The heater 25 heats the inside of the cooking chamber 20 and is wound in an approximately annular shape on the left side wall of the cooking chamber 20. The convection fan 26 circulates the air inside the cooking chamber 20 and is attached inside the heater 25 wound in an approximately annular shape on the left side wall of the cooking chamber 20. The convection fan 26 in this embodiment is a centrifugal fan consisting of a sirocco fan. When the convection fan 26 is operated, the air in the food storage chamber 21 is sucked into the hot air generating chamber 22 through the suction port 23a of the partition plate 23, and the sucked air is blown outward in the centrifugal direction in the hot air generating chamber 22, and the blown air is returned to the food storage chamber 21 through the upper, lower, front and rear ventilation paths 23b. In addition, when the convection fan 26 is operated together with the heater 25, the air sucked from the food storage chamber 21 into the hot air generation chamber 22 is blown onto the heater 25 arranged outside the convection fan 26, becoming high-temperature hot air, which is returned to the food storage chamber 21 through the upper and lower and front and rear ventilation passages 23b.

As shown in FIG. 5, a temperature sensor 27 is provided in the hot air generating chamber 22 of the cooking chamber 20. The temperature sensor 27 detects the temperature inside the cooking chamber 20 and is disposed outside the heater 25 on the left side wall of the cooking chamber 20.

As shown in FIG. 6, the machine room 12 of the housing 11 is provided with a steam generator 30 that supplies steam to the cooking chamber 20. The steam generator 30 generates steam by heating water through induction heating, and is installed above the tank 14 installed in the machine room 12. The tank 14 is used not only to drain wastewater from the steam generator 30, but also to drain wastewater from the cooking chamber 20, to measure the amount of steam in the cooking chamber 20 by detecting the temperature of the air discharged from the cooking chamber 20, and to store cleaning water when executing a cleaning program described later. The steam generator 30 includes a cylindrical steam generating vessel 31 that stores water at a predetermined water level, a heating element (not shown) that heats the water in the steam generating vessel 31, an induction heating coil 32 that is wound around the outer periphery of the steam generating vessel 31 to heat the heating element, and a steam delivery tube 33 that delivers the steam generated in the steam generating vessel 31 to the cooking chamber 20. The steam delivery tube 33 is connected to the steam inlet 20b formed on the left wall of the cooking chamber 20 shown in FIG. 5, and the steam generated in the steam generating container 31 is sent through the steam delivery tube 33 and from the steam inlet 20b into the cooking chamber 20.

As shown in Figures 3 and 6, the machine room 12 of the housing 11 is provided with an outside air introduction pipe 34 for introducing outside air into the cooking chamber 20. The outside air introduction pipe 34 mainly adjusts the temperature and humidity inside the cooking chamber 20 by introducing outside air into the cooking chamber 20 when cooking in the cooking chamber 20. As shown in Figures 3 and 5, an outside air introduction port 20c is formed on the back side (left side) of the convection fan 26 on the left side wall of the cooking chamber 20, and the outside air introduction pipe 34 is connected to this outside air introduction port 20c. When the convection fan 26 is operated, a negative pressure is created between the left side wall of the cooking chamber 20 and the convection fan 26, and outside air can be introduced into the cooking chamber 20 through the outside air introduction pipe 34. In addition, an outside air introduction valve 35 is interposed in the outside air introduction pipe 34, and outside air is introduced into the cooking chamber 20 through the outside air introduction pipe 34 in an amount according to the opening degree of the outside air introduction valve 35.

As shown in FIG. 7, a drain port 20d is formed in the bottom wall (bottom) of the cooking chamber 20, a cleaning nozzle 40 is provided in the ceiling of the cooking chamber 20, and the drain port 20d and the cleaning nozzle 40 are connected by a cleaning water passage. The drain port 20d is provided with a drainage strainer 15 that allows liquids such as cleaning water to pass through and prevents solid objects such as fallen ingredients from passing through, and the liquids such as cleaning water in the cooking chamber 20 can pass through the drainage strainer 15 to the tank 14. As shown in FIG. 7, the drain port 20d is connected to the tank 14 by the first drain pipe 16, and the cleaning water in the cooking chamber 20 is sent from the drain port 20d through the first drain pipe 16 to the tank 14. The tank 14 and the cleaning nozzle 40 are connected by a cleaning water delivery pipe 41, and the cleaning water in the tank 14 is sent to the cleaning nozzle 40 through the cleaning water delivery pipe 41. A pump 42 is installed in the cleaning water delivery pipe 41, and cleaning water sent from the cooking chamber 20 into the tank 14 is sent by the pump 42 through the cleaning water delivery pipe 41 to the cleaning nozzle 40. The cleaning water passage in this embodiment is composed of the first drain pipe 16 and the cleaning water delivery pipe 41, but is not limited to this and may be anything that connects the drain outlet 20d of the cooking chamber 20 and the cleaning nozzle 40.

As shown in FIG. 7, a water supply pipe 43 is connected to the tank 14, which supplies water for cleaning (cleaning water) from a water supply source such as a waterworks, and a water supply valve 44 and a flow meter 45 are interposed in the water supply pipe 43. Water from the water supply source is supplied into the tank 14 through the water supply pipe 43 by opening the water supply valve 44. The flow rate of water passing through the water supply pipe 43 when the water supply valve 44 is opened is measured by the flow meter 45.

The second drain pipe 17 is connected to the washing water delivery pipe 41 upstream of the pump 42 in the direction in which the washing water flows, and a drain valve 18 is interposed in the second drain pipe 17. Water including washing water in the tank 14 is discharged through the second drain pipe 17 by opening the drain valve 18. When washing water is circulated between the tank 14 and the cooking chamber 20, a predetermined amount of washing water is stored in the tank 14 by opening the water supply valve 44 for an opening time according to the flow rate detected by the flow meter 45 with the drain valve 18 closed. The washing water stored in the tank 14 is sent to the washing nozzle 40 through the washing water delivery pipe 41 by the operation of the pump 42, and the sent washing water is sprayed from the washing nozzle 40 into the cooking chamber 20. The washing water sprayed into the cooking chamber 20 is returned to the tank 14 through the first drain pipe 16 from the drain port 20d in the bottom wall of the cooking chamber 20. In this way, the washing water circulates between the tank 14 and the cooking chamber 20 by the operation of the pump 42.

As shown in FIG. 8, the cooking device 10 is equipped with a control device 50, which is connected to the door open/close detector 13a, the drain valve 18, the heater 25, the convection fan 26, the temperature sensor 27, the steam generator 30, the outside air introduction valve 35, the pump 42, the water supply valve 44, and the flow meter 45. The control device 50 has a microcomputer (not shown), which has a CPU, RAM, ROM, and a timer (all not shown) connected via a bus. The control device 50 also has an inverter circuit for supplying a drive current to the motor of the convection fan 26, and can change the rotation direction of the convection fan 26 between forward and reverse by controlling the drive of the inverter circuit.

The control device 50 has cooking programs in the ROM for heating and cooking ingredients in the cooking chamber 20. The cooking programs include three types of cooking programs: a hot air mode cooking program that operates the heater 25 and the convection fan 26 to heat and cook ingredients with convecting hot air containing steam, a steam mode cooking program that operates the convection fan 26 and the steam generator 30 to heat and cook ingredients with convecting hot air containing steam, and a combination mode cooking program that operates the heater 25, the convection fan 26 and the steam generator 30 to heat and cook ingredients with convecting high-temperature hot air containing steam. The ROM stores cooking programs in which the set temperature, amount of steam and cooking time in the cooking chamber 20 are preset, and the set temperature, amount of steam and cooking time of the cooking chamber 20 for the cooking program can be set by the user.

When the hot air mode cooking program of the cooking program is executed, the heater 25 and the convection fan 26 operate to cause the air in the cooking chamber 20 to circulate as hot air, and the food stored in the cooking chamber 20 is cooked by the convection of the hot air. When the combination mode cooking program of the cooking program is executed, the heater 25 and the convection fan 26 operate to cause the air in the cooking chamber 20 to circulate as hot air, and steam is supplied from the steam generator 30 to the cooking chamber 20, so that the hot air circulating in the cooking chamber 20 contains steam, and the food stored in the cooking chamber 20 is cooked by the convection of the hot air containing steam.

The control device 50 has a cleaning program in its ROM that automatically cleans the inside of the cooking chamber 20 with cleaning water. The cleaning program includes a first cleaning program that has a steam pre-cleaning operation that pre-cleans the inside of the cooking chamber 20 with steam and four (one or more) cleaning operations that clean the inside of the cooking chamber 20 with high-temperature cleaning water, and a second cleaning program that has four (one or more) cleaning operations that clean the inside of the cooking chamber 20 with high-temperature cleaning water without a steam pre-cleaning operation, and the first and second cleaning programs can be selected.

The steam pre-cleaning operation of the first cleaning program involves supplying steam into the cooking chamber 20 using the steam generator 30 to pre-clean the inside of the cooking chamber 20 with steam. The steam pre-cleaning operation causes oily stains (greasy dirt) adhering to the inside of the cooking chamber 20 to float up with the steam, making it easier to wash away with high-temperature cleaning water in the cleaning operation that follows the steam pre-cleaning operation.

The washing operation of the first and second washing programs is a process in which the washing water in the tank 14 is sent to the washing nozzle 40 by operating the pump 42, the sent washing water is sprayed from the washing nozzle 40 into the cooking chamber 20, the sprayed washing water is heated by the convection hot air by operating the heater 25 and the convection fan 26, and scattered inside the cooking chamber 20 in a state where it is heated, and the scattered high-temperature washing water is returned to the tank 14 from the drain outlet 20d, and the inside of the cooking chamber 20 is washed with the high-temperature washing water circulating between the tank 14. In this embodiment, the first and second washing programs are controlled to perform four washing operations, and the first washing operation is a washing operation in which high-temperature washing water containing detergent is sprayed into the cooking chamber 20 to wash, and the second and subsequent washing operations are a rinsing operation in which high-temperature washing water is sprayed into the cooking chamber 20 to wash away the washing water containing detergent remaining in the cooking chamber 20.

In the cleaning operation, the control device 50 controls the operation of the heater 25 so that the temperature inside the cooking chamber 20 is 90°C, which is an example of a temperature suitable for cleaning. In addition, in the cleaning operation, the control device 50 controls the convection fan 26 to alternate between forward and reverse rotation every two minutes as a predetermined time, and controls the operation of the pump 42 to be temporarily stopped for 10 seconds when the rotation direction of the convection fan 26 is changed. Note that the time for changing the rotation direction of the convection fan 26 is set to every two minutes, and the time for stopping the operation of the pump 42 when the rotation direction of the convection fan 26 is changed is set to 10 seconds, but this is not limited to this, and the time for changing the rotation direction of the convection fan 26 and the time for stopping the operation of the pump 42 may be set to other times as desired to provide the optimal timing for cleaning.

Next, the control of the first cleaning program will be described with reference to FIG. 9. When cleaning the inside of the cooking chamber 20, the cleaning program is executed with a tablet-shaped (low cylindrical) detergent placed on the top of the drainage strainer 15 installed in the drain outlet 20d of the cooking chamber 20. The cleaning program may be executed after cooking ingredients. If cleaning water is splashed into the cooking chamber 20 after cooking the ingredients, the peripheral walls of the cooking chamber 20 may be rapidly cooled by the cleaning water, which may cause deformation of the peripheral walls of the cooking chamber 20. For this reason, in step 101, the control device 50 determines whether the temperature detected by the temperature sensor 27 that detects the temperature inside the cooking chamber 20 is higher than 50°C, which is the suitable cleaning temperature.

If the temperature inside the cooking chamber 20 is below 50°C, which is the suitable cleaning temperature, the control device 50 judges NO in step 101 and proceeds to step 106 (step 200) described below. On the other hand, if the temperature inside the cooking chamber 20 is higher than 50°C, which is the suitable cleaning temperature, the control device 50 judges YES in step 101 and performs cooling operation until the temperature becomes below 50°C, which is the suitable cleaning temperature. After judging YES in step 101, the control device 50 displays a notification on the operation panel on the front of the housing 11 urging the user to open the door, and in step 102, the door opening/closing detector 13a judges whether the door 13 is open or not, and if the door opening/closing detector 13a does not detect that the door 13 is open, the process returns to step 102.

In step 102, the control device 50 repeatedly judges NO until the door 13 is opened by the door open/close detector 13a. When the door open/close detector 13a detects that the door 13 is open, the control device 50 judges YES in step 102 and proceeds to step 103. In step 103, the control device 50 operates the convection fan 26 and opens the outside air introduction valve 35. The air outside the housing 11 is sucked into the cooking chamber 20 through the outside air introduction pipe 34 under negative pressure, and the temperature inside the cooking chamber 20 gradually drops due to the outside air being introduced. In step 104, the control device 50 judges whether the temperature detected by the temperature sensor 27 is below 50°C, which is the suitable cleaning temperature. If the temperature inside the cooking chamber 20 is not below the suitable cleaning temperature, the control device 50 judges NO in step 104 and returns to step 103.

The control device 50 repeatedly executes the process of step 103 and the determination of NO in the determination process of step 104 until the temperature inside the cooking chamber 20 falls below 50°C. When the temperature detected by the temperature sensor 27 falls below 50°C, the control device 50 determines YES in step 104 and proceeds to step 105. In step 105, the control device 50 stops the operation of the convection fan 26 and closes the outside air introduction valve 35, and proceeds to steam pre-cleaning operation in step 106 (step 200).

The steam pre-wash operation shown in step 106 (step 200) is a process for mainly floating oily stains by supplying steam into the cooking chamber 20 before performing a cleaning operation that includes detergent inside the cooking chamber 20. The steam pre-wash operation controls the operation of the steam generator 30 based on the temperature detected by the temperature sensor 27 so that the temperature inside the cooking chamber 20 becomes 100°C, which is an example of a steam cleaning temperature that can float oily stains. In this embodiment, the steam pre-wash operation in step 105 (step 200) is controlled to be performed for 30 minutes. The execution time of the steam pre-wash operation can be set, for example, between 14 and 40 minutes.

10, when the control device 50 operates the steam generator 30 in step 201, steam is supplied from the steam generator 30 to the cooking chamber 20. In step 202, the control device 50 determines whether 30 minutes have elapsed since the timer counted the operating time of the steam pre-cleaning operation, and returns to step 201 with a NO determination until 30 minutes have elapsed. When 30 minutes have elapsed since the timer counted the operating time of the steam pre-cleaning operation, the control device 50 determines YES in step 202 and proceeds to step 203. In step 203, the control device 50 stops the operation of the steam generator 30, and proceeds to drainage treatment in step 204. Condensation that has formed inside the cooking chamber 20 as a result of the processing of steps 201 and 202 has accumulated in the tank 14, and the control device 50 opens the drain valve 18 for 2.5 minutes as a drainage process in step 204, and the water that has accumulated in the tank 14 is drained to the outside through the second drain pipe 17. The drain valve 18 is controlled to close after 2.5 minutes.

As shown in FIG. 9, when the control device 50 finishes the steam pre-cleaning operation in step 106 (step 200), it executes the cleaning operation in step 107 (step 300). The cleaning operation in step 107 (step 300) is to clean the inside of the cooking chamber 20 with high-temperature cleaning water. The cleaning operation in step 107 (step 300) is controlled to be executed four times. In the first cleaning operation, the detergent placed on the upper side of the drainage strainer 15 dissolves in the cleaning water, so that the inside of the cooking chamber 20 is cleaned with cleaning water containing detergent. The second and subsequent cleaning operations are rinse cleaning operations that wash away the cleaning water containing detergent remaining in the cooking chamber 20 due to the first cleaning operation. In this embodiment, the cleaning operation in step 106 (step 300) is controlled to be executed for 30 minutes.

As shown in FIG. 11, in the washing operation of step 300 (step 107), the control device 50 first executes a water supply process in step 301. In the water supply process, the control device 50 opens the water supply valve 44 for an opening time according to the flow rate measured by the flow meter 45, and the tank 14 stores the amount of washing water required for the washing operation. In step 302, the control device 50 operates the heater 25, the convection fan 26, and the pump 42, and starts timing with a timer that measures the operating time of the convection fan 26 while controlling the operation of the heater 25 so that the temperature of the washing water becomes 90°C, which is a temperature suitable for washing. The washing water in the tank 14 is sent to the washing nozzle 40 by the operation of the pump 42, and the washing water sent to the washing nozzle 40 is sprayed into the cooking chamber 20, and the washing water sprayed into the cooking chamber 20 is splashed inside the cooking chamber 20 by the convection fan 26, and the inside of the cooking chamber 20 is washed by the splashed washing water.

When the timer that measures the operation time of the convection fan 26 has elapsed for two minutes while controlling the operation of the heater 25 so that the temperature of the washing water during this washing operation is 90°C, which is a temperature suitable for washing, the control device 50 judges YES in step 303 and proceeds to step 304. In step 304, the control device 50 resets the timer that measures the operation time of the convection fan 26 and uses the timer to measure a new operation time of the convection fan 26. In step 305 after processing in step 304, the control device 50 temporarily stops the convection fan 26 and reverses the rotation direction of the convection fan 26, i.e., from clockwise forward rotation to counterclockwise reverse rotation, or from counterclockwise reverse rotation to clockwise forward rotation. At the same time, the control device 50 temporarily stops the operation of the pump 42 for 10 seconds.

When the convection fan 26 is operating, the washing water that temporarily accumulates at the bottom of the cooking chamber 20 flows into the drain port 20d while swirling due to the convection of hot air. If the convection fan 26 is temporarily stopped when the rotation direction of the convection fan 26 is reversed, the flow of washing water at the bottom of the cooking chamber 20 changes, the amount of washing water at the bottom of the cooking chamber 20 temporarily increases, and the amount of washing water in the tank 14 temporarily decreases. If the pump 42 continues to operate when the rotation direction of the convection fan 26 is reversed, the pump 42 may suck in the reduced amount of washing water in the tank 14 together with air, and the pump 42 may suck in air together with the washing water, resulting in so-called air entrapment. Therefore, when the convection fan 26 is temporarily stopped and its rotation direction is reversed, the control device 50 temporarily stops the operation of the pump 42 for 10 seconds, so that the pump 42 does not suck in cleaning water from the tank 14 whose water level has temporarily dropped, and it is possible to reliably prevent the pump 42 from sucking in air along with the cleaning water, i.e., so-called air entrainment.

In step 306 after processing in step 305, the control device 50 determines whether 45 minutes have elapsed since the timer counted down the operation time of the cleaning operation, and if 30 minutes have not elapsed since the timer counted down the operation time of the cleaning operation, it determines NO and returns to step 303.

The control device 50 controls the operation of the heater 25 so that the temperature detected by the temperature sensor 27 during this cleaning operation is 90°C, which is a temperature suitable for cleaning, and in steps 303 to 305, the control device 50 controls the rotation direction of the convection fan 26 to change every two minutes as a predetermined time, and temporarily stops the operation of the pump 42 for 10 seconds when changing the rotation direction of the convection fan 26. When the timer that counts the operation time of the cleaning operation reaches 45 minutes, the control device 50 judges YES in step 306 and proceeds to step 307.

In step 307, the control device 50 controls the heater 25, the convection fan 26, and the pump 42 to stop operating. In the drainage process in step 308 after the process in step 307, the control device 50 opens the drain valve 18 for 2.5 minutes. The cleaning water in the tank 14 is discharged to the outside through the second drain pipe 17, and the drain valve 18 is closed after 2.5 minutes.

As shown in FIG. 9, after the cleaning operation in step 107 (step 300), the control device 50 judges in step 108 whether the cleaning operation has been performed four times, and if the cleaning operation has not been performed four times, the control device 50 judges NO in step 108 and returns to step 107, and executes the above-mentioned processing in step 107 (step 300) again. The second and subsequent cleaning operations are rinsing operations to wash away the cleaning water containing detergent remaining in the cooking chamber 20 due to the first cleaning operation, and since the operating time of the rinsing cleaning operation is 8 minutes, the judgment processing in step 310 in the second and subsequent cleaning operations judges whether the operating time of the cleaning operation has elapsed for 8 minutes. If the rinsing cleaning operation is performed three times after the cleaning operation using cleaning water containing detergent, and the cleaning operation using cleaning water containing detergent and the rinsing cleaning operation are performed four times in total, the control device 50 judges YES in step 108 and proceeds to the drying operation in step 109 (step 400). The drying operation in step 109 (step 400) is a process in which the convection fan 26 is operated while the operation of the heater 25 is controlled to evaporate the cleaning water remaining in the cooking chamber 20 and dry the inside of the cooking chamber 20. In this embodiment, the drying operation in step 109 (step 400) is controlled to be performed for 40 minutes.

As shown in FIG. 12, in the drying operation of step 109 (step 400), the control device 50 operates the heater 25 and the convection fan 26 in step 401, and controls the operation of the heater 25 so that the temperature inside the cooking chamber 20 becomes 140°C, which is a temperature suitable for drying. The air inside the cooking chamber 20 is heated by the heater 25 while being circulated between the food storage chamber 21 and the hot air generating chamber 22 by the convection fan 26. In step 402, the control device 50 determines whether the timer that measures the operation time of the drying operation has reached 40 minutes, and if the timer that measures the operation time of the drying operation has not reached 40 minutes, the control device 50 determines NO and returns to step 401.

In step 401, the control device 50 controls the operation of the heater 25 so that the temperature inside the cooking chamber 20 is 140°C, which is a temperature suitable for drying. When the timer that measures the operation time of the drying operation has elapsed for 40 minutes, the control device 50 judges YES in step 402 and proceeds to step 403. In step 403, the control device 50 stops the operation of the heater 25 and the convection fan 26 to end the drying operation. This end of the drying operation ends the first cleaning program. Note that the second cleaning program does not have the steam pre-cleaning operation of step 106 (step 200) of the first cleaning program shown in Figures 9 and 10, so a detailed description will be omitted. In addition, the second cleaning program may have only one of the first cleaning program and the second cleaning program. Furthermore, the temperature and time of the steam pre-cleaning operation, the cleaning operation, and the drying operation are not limited to those described above, and may be set arbitrarily depending on the size of the cooking chamber 20 and the degree of dirt.

The cooking device 10 configured as described above includes a control device 50 that controls the operation of the convection fan 26 and the pump 42. The control device 50 operates the pump 42 to send cleaning water in the tank 14 to the cleaning nozzle 40, sprays the sent cleaning water from the cleaning nozzle 40 into the cooking chamber 20, operates the convection fan 26 to scatter the sprayed cleaning water into the cooking chamber 20 by the convecting air, and returns the scattered cleaning water to the tank 14 from the drain outlet 20d of the cooking chamber 20. The control device 50 has a cleaning program (cleaning operation of the first and second cleaning programs) that cleans the inside of the cooking chamber 20 with the cleaning water circulating between the tank 14 and the cleaning water.

When the control device 50 is executing the cleaning operation of each cleaning program, it controls the convection fan 26 to alternate between forward and reverse rotation every two minutes as a predetermined time, and the cleaning water sprayed from the cleaning nozzle 40 is scattered to every corner of the cooking chamber 20 by the air flow of the convection fan 26, which alternates between forward and reverse rotation. When cleaning water is sprayed from the cleaning nozzle 40 into the cooking chamber 20, the air flow of the convection fan 26 causes the cleaning water that temporarily accumulates at the bottom of the cooking chamber 20 to swirl and flow into the drain outlet 20d. When the operation of the convection fan 26 is temporarily stopped in order to change the rotation direction of the convection fan 26, the flow of the cleaning water at the bottom of the cooking chamber 20 changes, and the amount of cleaning water that accumulates at the bottom of the cooking chamber 20 temporarily increases, and as a result, the amount of cleaning water in the tank 14 temporarily decreases.

In this state, if the pump 42 continues to operate, the pump 42 may suck air together with the cleaning water from the tank 14, which may cause so-called air entrapment, in which the pump 42 sucks in air together with the cleaning water. In the cleaning operation of each cleaning program in this embodiment, the control device 50 controls the operation of the pump 42 to be temporarily stopped for 10 seconds when the rotation direction of the convection fan 26 is changed. As a result, even if the amount of cleaning water accumulating at the bottom of the cooking chamber 20 temporarily increases due to the stopping of the convection fan 26 when the rotation direction of the convection fan 26 is changed, and the amount of cleaning water accumulating in the tank 14 temporarily decreases, the pump 42 is temporarily stopped for 10 seconds (10 seconds is an example and is not limited to this), so that it is possible to prevent the pump 42 from sucking in air together with the cleaning water, which may cause so-called air entrapment.

In this embodiment, the control device 50 controls the pump 42 to temporarily stop operation when the rotation direction of the convection fan 26 is changed. The present invention is not limited to this, and as shown in FIG. 13, a water level sensor 14a may be provided in the tank 14, and the control device 50 may control the pump 42 to operate again when the water level sensor 14a detects a water level at which no air flows into the pump 42 after the pump 42 is temporarily stopped when the rotation direction of the convection fan 26 is changed. Since the pump 42 is controlled to operate again after the water level in the tank 14 reaches a water level at which no air flows into the pump 42, it is possible to reliably prevent the pump 42 from sucking in air together with the cleaning water, i.e., so-called air entrapment.

In addition, when cleaning water is sprayed from the cleaning nozzle 40 and the convection fan 26 is operated, the cleaning water that accumulates at the bottom of the cooking chamber 20 swirls and flows into the drain outlet 20d in the center. At this time, the cleaning water that accumulates at the bottom of the cooking chamber 20 spreads over the entire bottom of the cooking chamber 20 due to the centrifugal force of the vortex water flow, so the cleaning water in the tank 14 tends to decrease. If the cleaning water is prevented from swirling at the bottom of the cooking chamber 20, the cleaning water that accumulates at the bottom of the cooking chamber 20 can be prevented from spreading over the entire bottom, and the cleaning water in the tank 14 can be prevented from decreasing. As shown in FIG. 14, when a guide 15a is provided on the top of the drainage strainer 15 detachably provided on the drain outlet 20d, on which three tablet-shaped (low cylindrical) solid detergents can be placed horizontally in an upright state, the three solid detergents placed on the guide 15a block the swirling flow of the washing water at the bottom of the cooking chamber 20, and the washing water can be prevented from swirling at the bottom of the cooking chamber 20. In this way, by using the drainage strainer 15 at the bottom of the cooking chamber 20 to prevent the washing water at the bottom of the cooking chamber 20 from swirling, it is possible to prevent so-called air entrapment, in which the pump 42 sucks in air together with the washing water due to a small amount of washing water in the tank 14. Note that the guide 15a is shaped like the Chinese character "一" that extends linearly in a plan view, but is not limited to this, and the guide 15a may be shaped like the Chinese character "次" in a plan view to allow five solid detergents to be placed.

10... cooking device, 14... tank, 14a... water level sensor, 20... cooking chamber, 20d... drain, 26... convection fan, 40... cleaning nozzle, 42... pump, 16, 41... cleaning water passage, 50... control device.

Claims (2)

A kitchen for heating and cooking ingredients;
A convection fan for circulating air in the cooking chamber;
A drain outlet provided at the bottom of the cooking chamber;
A cleaning nozzle provided on the ceiling of the cooking chamber for spraying cleaning water;
a cleaning water passage connecting the drain outlet and the cleaning nozzle;
a tank provided in the flush water passage for temporarily storing the flush water;
a pump that delivers cleaning water in the tank to the cleaning nozzle;
a control device for controlling the operation of the convection fan and the pump;
The control device operates the pump to send cleaning water in the tank to the cleaning nozzle and spray it from the cleaning nozzle into the cooking chamber, operates the convection fan to scatter the sprayed cleaning water into the cooking chamber by convective air, and returns the scattered cleaning water to the tank from the drain outlet, and the cooking chamber is cleaned with the cleaning water circulating between the tank and the control device,
The control device controls the convection fan to alternately change its rotation direction between forward and reverse at predetermined time intervals while executing the cleaning program, and controls the operation of the pump to temporarily stop at the timing when the rotation direction of the convection fan is changed. The cooking device according to claim 1,
a water level sensor for detecting a water level in the tank;
The control device controls the pump to be temporarily stopped when the rotation direction of the convection fan is changed, and then to operate the pump again when the water level sensor detects a water level at which no air flows into the pump.

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