dishwasher

Abstract

To provide a dishwasher capable of further improving washing capacity.SOLUTION: The dish washer 1 is provided with a microbubble generator 10 for containing microbubbles in washing water for washing the TW1 of the object to be washed. A state in which the washing water contains the microbubbles is referred to as a microbubble-containing state, and a state in which the washing water contains the detergent is referred to as a detergent-containing state. The dish washer 1 is configured to execute a first washing process of washing the TW1 of the object to be washed using wash water in at least the microbubble containing state out of the microbubble containing state and the detergent containing state, and a second washing process of washing the TW1 of the object to be washed using wash water in at least the detergent containing state out of the microbubble containing state and the detergent containing state. A first upper limit temperature TU1 that is an upper limit temperature of the washing water in the first washing step is lower than a second upper limit temperature TU2 that is an upper limit temperature of the washing water in the second washing step.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to dishwashers. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional dishwasher. This dishwasher is equipped with a micro-bubble generator. The micro-bubble generator adds micro-bubbles to the wash water used to wash the objects.

[0003] The microscopic bubbles contained in the cleaning water are electrically charged and hydrophobic, and they surround the object to be cleaned and adsorb dirt, oil, etc. The microscopic bubbles then capture the dirt, etc. at the gas-liquid interface and detach it from the object to be cleaned, thereby achieving a cleaning effect.

[0004] This dishwasher aims to improve washing performance by performing a washing process in which items to be washed are washed using washing water containing detergent and fine bubbles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-175445 Summary of the Invention [Problem to be solved by the invention]

[0006] However, there is a demand for further improvement in the washing performance of the conventional dishwashers.

[0007] The present invention has been made in view of the above-mentioned conventional circumstances, and an object to be achieved is to provide a dishwasher that can further improve the washing performance. [Means for solving the problem]

[0008] In pursuit of improving the cleaning ability of fine bubbles, the inventors reviewed the latest research papers on fine bubbles and noted papers demonstrating that the number of fine bubbles contained in water decreases when the temperature of water containing fine bubbles, particularly ultrafine bubbles with a diameter of less than 1 μm, increases.The inventors then came up with the present invention based on the belief that since ordinary dishwashers use wash water at a relatively high temperature of around 60°C in order to improve cleaning power in the washing process, the number of fine bubbles contained in the wash water may decrease, making it difficult for the fine bubbles to exert their cleaning effect.

[0009] The dishwasher of the present invention is a dishwasher equipped with a microbubble generator that adds microbubbles to the wash water used to wash items, The state in which the cleaning water contains the microbubbles is referred to as a microbubble-containing state, The state in which the cleaning water contains a detergent is referred to as a detergent-containing state, a first cleaning step of cleaning the object using the cleaning water in at least the microbubble-containing state out of the microbubble-containing state and the detergent-containing state; a second cleaning step of cleaning the object using the cleaning water in at least the detergent-containing state out of the microbubble-containing state and the detergent-containing state; configured to run A first upper limit temperature, which is the upper limit temperature of the cleaning water in the first cleaning step, is lower than a second upper limit temperature, which is the upper limit temperature of the cleaning water in the second cleaning step.

[0010] In the dishwasher of the present invention, in at least the first washing step using wash water containing microbubbles, the first upper limit temperature is lower than the second upper limit temperature in the second washing step. This makes it possible to prevent a decrease in the number of microbubbles contained in the wash water in the first washing step, and as a result, to effectively maintain a state in which the cleaning effect of the microbubbles is exerted.

[0011] Furthermore, in the second washing step, which uses washing water containing at least detergent, the second upper limit temperature is higher than the first upper limit temperature in the first washing step. This allows the dishwasher to promote softening of dirt, oil, etc. adhering to the items to be washed in the second washing step, and promote dissolution or decomposition of dirt, etc. adhering to the items to be washed in the washing water, making it easier for the detergent to exert its cleaning effect.

[0012] Therefore, the dishwasher of the present invention can further improve the washing performance.

[0013] The dishwasher of the present invention preferably performs a second washing step after the first washing step.

[0014] In this case, in the first washing step, the fine bubbles contained in the washing water surround the object to be washed and adsorb to dirt and other contaminants adhering to the object, trapping the dirt and other contaminants at the gas-liquid interface and then peeling off the object together with the trapped dirt and other contaminants. As a result, in the second washing step performed after the first washing step, dirt and other contaminants are more easily peeled off from the object to be washed than if only the second washing step were performed or if the first washing step were performed after the second washing step. As a result, the dishwasher can further improve its washing performance.

[0015] In the dishwasher of the present invention, it is desirable that in the second washing step, the items to be washed are washed using washing water that contains fine bubbles and detergent.

[0016] In this case, in the second washing step performed after the first washing step, the synergistic effect of the detergent and the fine bubbles makes it easier to remove dirt and other particles from the items being washed. As a result, the dishwasher can further improve its cleaning performance. In addition, in this case, there is no need to provide a switching mechanism for switching the fine bubble generator on and off between the first washing step and the second washing step, which simplifies the system.

[0017] The dishwasher of the present invention preferably performs the second washing cycle after the first washing cycle without draining the washing water.

[0018] In this case, the low-temperature wash water used in the first wash step can be heated and used as high-temperature wash water in the second wash step. As a result, this dishwasher can achieve water and energy savings compared to a case in which the second wash step is performed after draining and refilling the wash water after the first wash step. [Effects of the Invention]

[0019] According to the dishwasher of the present invention, the washing performance can be further improved. [Brief explanation of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic cross-sectional view of a dishwasher according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart of the cleaning operation. DETAILED DESCRIPTION OF THE INVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

[0022] (Example) As shown in Figure 1, the dishwasher 1 of the embodiment is an example of a specific embodiment of the dishwasher of the present invention. The dishwasher 1 is a front-drawer type with a sliding washing tub 7, and is placed below the countertop CT1 of the system kitchen.

[0023] <Housing, cleaning tank and lid> Dishwasher 1 includes a housing 9, a washing tub 7, and a lid 8. In this embodiment, the side of housing 9, which is roughly box-shaped, facing a user who uses the system kitchen, i.e., the left side of the paper in Fig. 1, is defined as the front side of housing 9, and the right side of the paper in Fig. 1 is defined as the rear side of housing 9.

[0024] The upper surface of the housing 9 is covered by a top plate CT1. The housing 9 has a housing opening 9H. The housing opening 9H opens a wide area from the top to the bottom of the front of the housing 9. The housing opening 9H connects the inside of the housing 9 to the outside.

[0025] The cleaning tank 7 is housed in a housing 9. The position of the cleaning tank 7 shown in Fig. 1 is the housing position. When the cleaning tank 7 is in the housing position, the front wall of the cleaning tank 7 closes the housing opening 9H.

[0026] A slide rail mechanism (not shown) is disposed between the side surface of the approximately box-shaped cleaning tank 7 and the inner wall surface of the housing 9. Although not shown, the slide rail mechanism allows the cleaning tank 7 to slide in the front-to-rear direction relative to the housing 9.

[0027] The cleaning tank 7 has a tank opening 7H. The tank opening 7H opens the top side of the cleaning tank 7. A handle 7G is provided at the top end of the front wall of the cleaning tank 7.

[0028] The user grips the handle 7G and manually slides the cleaning tank 7 forward from the storage position, which causes the cleaning tank 7 to be pulled out forward from the housing 9 (not shown). The user can also manually slide the pulled-out cleaning tank 7 backward, which returns the cleaning tank 7 to the storage position.

[0029] The lid 8 is disposed at the top inside the housing 9. The lid 8 is supported by a linkage mechanism (not shown) so as to move up and down in conjunction with the sliding of the cleaning tank 7.

[0030] The cover 8 closes the tank opening 7H when the cleaning tank 7 is in the storage position. On the other hand, although not shown, the cover 8 rises to open the tank opening 7H and allow the cleaning tank 7 to slide when the cleaning tank 7 is in the process of being pulled out from the storage position, when the cleaning tank 7 has been pulled out from the storage position, and when the cleaning tank 7 is in the process of returning to the storage position.

[0031] A water storage section 71 is provided at the bottom of the washing tub 7. The water storage section 71 stores, as washing water, water supplied to the washing tub 7. The water storage section 71 is divided into an upper section and a lower section by the food residue filter 67.

[0032] A dish basket 70 is provided in the washing tub 7. In the dish basket 70, tableware TW1 to be accommodated in the washing tub 7 is placed.

[0033] The tableware TW1 is, for example, tableware such as bowls, plates, glasses, etc., and eating and drinking utensils such as chopsticks, spoons, forks, etc. The tableware TW1 is an example of the "item to be washed" in the present invention.

[0034] Although not shown, when the washing tub 7 is pulled out from the housing 9, the user can place tableware TW1 in the washing tub 7 or remove it from the washing tub 7 through the tub opening 7H.

[0035] <Water supply pipe, water supply solenoid valve and drain pipe> A water supply pipe P1, a water supply electromagnetic valve 69, and a drain pipe P2 are provided inside the housing 9. The water supply pipe P1 and the drain pipe P2 each have a following portion that is bent in an inverted "U" shape and can follow the sliding of the cleaning tank 7.

[0036] The upstream end of water supply pipe P1 is connected to a water supply source (not shown) provided outside dishwasher 1. The downstream end of water supply pipe P1 is connected to the rear wall of washing tub 7. Water supply pipe P1 supplies water from the water supply source (not shown) to washing tub 7.

[0037] The water supply electromagnetic valve 69 is provided on the upstream end side of the water supply pipe P1. The water supply electromagnetic valve 69 opens and closes the water supply pipe P1 to switch between supplying and stopping water to the washing tank 7.

[0038] The upstream end of drain pipe P2 is connected to drain outlet 62B of pump 62, which will be described later. The downstream end of drain pipe P2 is connected to a drain path (not shown) provided outside dishwasher 1. Drain pipe P2 drains the wash water stored in water storage section 71 to the outside of dishwasher 1 when pump 62 rotates in the reverse direction.

[0039] <Nozzles and pumps> The dishwasher 1 further includes a nozzle 61 and a pump 62. The nozzle 61 is disposed in the washing tub 7. The pump 62 is attached to the bottom wall of the washing tub 7. The nozzle 61 and the pump 62 move together with the washing tub 7 when the washing tub 7 is moved in and out.

[0040] The intake port of the pump 62 communicates with the lower part of the water storage section 71. The pump 62 has an ejection outlet 62A and a drainage outlet 62B.

[0041] Pump 62 rotates forward to discharge the wash water stored in water storage section 71 from spray outlet 62A. On the other hand, pump 62 rotates reverse to discharge the wash water stored in water storage section 71 from drain outlet 62B, and drain the water outside dishwasher 1 through drain pipe P2.

[0042] The nozzle 61 is connected to a jetting outlet 62A of the pump 62. The nozzle 61 can jet cleaning water into the cleaning tank 7 from a plurality of outlet holes when the pump 62 rotates forward.

[0043] The direction of spraying cleaning water from the nozzle 61 can be changed in various directions to ensure that multiple pieces of tableware TW1 stacked in the dish basket 70 are washed reliably and to clean the inner wall surface of the washing tank 7 and the dish basket 70.

[0044] The wash water sprayed from the nozzle 61 returns to the water reservoir 71 and is then repeatedly supplied to the nozzle 61 by the pump 62 .

[0045] <Heater, temperature sensor, drying fan and water level sensor> The dishwasher 1 further includes a heater 63, a temperature sensor 31, a drying fan 68 and a water level sensor .

[0046] The heater 63 is disposed at the bottom of the water storage section 71. The drying fan 68 is attached to the rear wall of the cleaning tank 7. An exhaust passage 79 is provided in the front wall of the cleaning tank 7 to exhaust the air sent into the cleaning tank 7 by the drying fan 68. The temperature sensor 31 is attached to a portion of the bottom wall of the water storage section 71 located below the heater 63.

[0047] The heater 63 heats the cleaning water stored in the water storage section 71 or the air in the cleaning tank 7. The temperature sensor 31 detects the temperature in the cleaning tank 7. More specifically, the temperature sensor 31 detects the temperature of the cleaning water stored in the water storage section 71 or the air in the cleaning tank 7 in the vicinity of the heater 63.

[0048] For example, when cleaning water is stored in the water storage section 71, the heater 63 is controlled to be energized and continuously generate heat or stop generating heat, thereby heating the cleaning water to a predetermined temperature range and spraying it into the cleaning tank 7 by the nozzle 61 and pump 62.

[0049] In addition, when no cleaning water is stored in the water storage section 71, the heater 63 is controlled to be energized and continuously generate heat or stop generating heat, thereby heating the air in the cleaning tank 7 to a predetermined temperature range.

[0050] Drying fan 68 rotates while heater 63 is operating, sending heated air into washing tub 7 to dry tableware TW1. The air sent into washing tub 7 by drying fan 68 is exhausted to the outside of dishwasher 1 via exhaust passage 79.

[0051] Water level sensor 34 is a float-type sensor provided in water level detection tank 34A, which is arranged next to water storage section 71 of cleaning tank 7. Water level detection tank 34A is connected to water storage section 71 via a communication pipe. Water level sensor 34 detects the level of cleaning water in cleaning tank 7.

[0052] <Control unit, operation unit and display unit> The dishwasher 1 further includes a control unit C1 and an input / output unit 40. The control unit C1 is located below the handle 7G on the front wall of the washing tub 7. The input / output unit 40 is located at the upper end of the front wall of the washing tub 7.

[0053] The control unit C1 is an electronic circuit unit including a CPU (not shown), a memory unit C1M, an interface circuit (not shown) that transmits and receives signals to and from the controlled object, and a power supply circuit (not shown) that controls the power supply to the controlled object.

[0054] The memory unit C1M is composed of memory elements such as ROM and RAM. The memory unit C1M stores various programs executed by the control unit C1 to operate the dishwasher 1, such as the wash operation program shown in Fig. 2. The memory unit C1M also stores various information such as setting information for the dishwasher 1, and initial setting information for executing the various programs, as needed.

[0055] 2, the control unit C1 controls and operates the pump 62, the heater 63, the drying fan 68, etc. The control unit C1 also controls the water supply electromagnetic valve 69 to open and close the water supply pipe P1.

[0056] The control unit C1 receives detection signals from the temperature sensor 31 and the water level sensor 34. The control unit C1 also receives detection signals from sensors (not shown), such as a position sensor that detects whether the cleaning tank 7 is in the storage position or not, and a lock sensor that detects whether the cleaning tank 7 is locked in the storage position or not.

[0057] The input / output unit 40 receives user instructions for operating the dishwasher 1 through an operation instruction unit having multiple buttons. The input / output unit 40 also displays information related to the operation and settings of the dishwasher 1 transmitted from the control unit C1 through a display unit such as a liquid crystal panel.

[0058] <Fine bubble generator> As shown in Figure 1, the dishwasher 1 further includes a fine-bubble generator 10. The fine-bubble generator 10 is disposed between the following portion and the downstream end of the water supply pipe P1.

[0059] The fine-bubble generator 10 generates fine bubbles in the water flowing through the water supply pipe P1 when the water supply electromagnetic valve 69 opens the water supply pipe P1 to supply water to the washing tub 7. In other words, the fine-bubble generator 10 makes the washing water used to wash the tableware TW1 contain fine bubbles. There are various known methods for generating fine bubbles, but in this embodiment, the fine-bubble generator 10 does not require an external gas supply.

[0060] Although not shown, the micro-bubble generator 10 incorporates a venturi member and a plurality of stirring members located downstream of the venturi member.

[0061] The venturi member has a plurality of venturi flow passages formed therein. Each venturi flow passage has a throttling portion that is narrowed midway, a narrowing flow passage that narrows in diameter from the upstream side toward the throttling portion, and an expanding flow passage that widens in diameter from the throttling portion toward the downstream side. Each stirring member has a plurality of blades formed therein.

[0062] The fine-bubble generator 10 converts air already dissolved in water passing through the Venturi flow path into bubbles, and then further refines the bubbles using each stirring member, thereby generating fine bubbles containing bubbles with a diameter of less than 1 μm in the water flowing through the water supply pipe P1. In this embodiment, the fine-bubble generator 10 is a so-called "ultra-fine bubble generator."

[0063] <Washing operation> In the dishwasher 1 having the above configuration, the control unit C1 executes the washing operation according to the flowchart shown in Fig. 2. During this operation, the control unit C1 executes the first washing step, the second washing step, the draining step, the non-heated rinsing step, the draining step, the heated rinsing step, the draining step, and the drying step in this order, as will be described below.

[0064] Before starting the washing operation, the user grasps the handle 7G and pulls out the washing tub 7 from the storage position to place the tableware TW1 to be washed into the washing tub 7. Then, the user places the tableware TW1 into the washing tub 7 through the opened tub opening 7H.

[0065] The user also pours detergent into a predetermined location in the washing tub 7 in an amount that corresponds to the number of pieces of tableware TW1 contained in the washing tub 7 and the level of dirt, oil, etc. adhering to the tableware TW1.

[0066] Thereafter, the user operates the input / output unit 40 to instruct the start of the cleaning operation, and moves the cleaning tank 7 to the storage position.

[0067] As a result, the control unit C1 starts the cleaning operation on the condition that a position sensor (not shown) detects that the cleaning tank 7 is in the storage position and a lock sensor (not shown) detects that the cleaning tank 7 is locked in the storage position.

[0068] First, in step S101, the control unit C1 executes the first cleaning step. The control unit C1 controls the water supply electromagnetic valve 69 to open the water supply pipe P1 and supply water to the cleaning tank 7. At this time, the micro-bubble generator 10 generates micro-bubbles in the water flowing through the water supply pipe P1, so that the cleaning water stored in the water storage unit 71 contains micro-bubbles. The state in which the cleaning water contains micro-bubbles is referred to as a micro-bubble-containing state.

[0069] When the control unit C1 determines, based on the detection signal from the water level sensor 34, that a sufficient amount of flush water has been stored in the water storage unit 71, it controls the water supply electromagnetic valve 69 to close the water supply pipe P1 and stop the supply of water to the washing tank 7. Then, the control unit C1 activates the pump 62 and heater 63.

[0070] As the pump 62 rotates forward, the nozzle 61 sprays the wash water containing fine bubbles in various directions within the wash tub 7. The detergent introduced into a predetermined location within the wash tub 7 gradually dissolves in the sprayed wash water. As a result, the wash water stored in the water storage section 71 and repeatedly sprayed from the nozzle 61 becomes detergent-containing. The state in which the wash water contains detergent is referred to as a detergent-containing state.

[0071] The nozzle 61 sprays the cleaning water containing fine bubbles and detergent in various directions within the cleaning tank 7.

[0072] That is, the first washing step is a step of washing tableware TW1 using washing water in at least a microbubble-containing state out of a microbubble-containing state and a detergent-containing state. In this embodiment, the dishwasher 1 washes tableware TW1 using washing water in a microbubble-containing state and a detergent-containing state in the first washing step.

[0073] The heater 63 heats the wash water containing fine bubbles and detergent. Since the water supplied from a water supply source (not shown) is at room temperature, the temperature of the wash water rises from room temperature. The control unit C1 sets the upper limit temperature of the wash water in the first wash step as the first upper limit temperature TU1. The control unit C1 determines the temperature of the wash water based on the detection signal of the temperature sensor 31.

[0074] When the temperature of the cleaning water rises from room temperature to the first upper limit temperature TU1, the control unit C1 controls the heater 63 so that the temperature of the cleaning water does not exceed the first upper limit temperature TU1 and so that the temperature decrease from the first upper limit temperature TU1 is equal to or less than the temperature fluctuation range TD1. Then, when a predetermined required time has elapsed, the control unit C1 ends the first cleaning step.

[0075] In this embodiment, as an example, the first upper limit temperature TU1 is 40° C., the temperature fluctuation range TD1 is 5° C., and the time required for the first cleaning step is 30 minutes.

[0076] In the first washing step, the fine bubbles contained in the washing water are electrically charged and hydrophobic, surround the tableware TW1, adsorb to dirt and other contaminants adhering to the tableware TW1, capture the dirt and other contaminants at the gas-liquid interface, and then peel off from the tableware TW1 together with the captured dirt and other contaminants. The detergent contained in the washing water promotes the dissolution and decomposition of dirt and other contaminants adhering to the tableware TW1 and dirt and other contaminants captured in the fine bubbles into the washing water.

[0077] Next, the control unit C1 proceeds to step S102 and executes the second cleaning step. The control unit C1 executes the second cleaning step without draining the cleaning water after the first cleaning step.

[0078] The control unit C1 continues to operate the pump 62. The nozzle 61 sprays the cleaning water containing fine bubbles and detergent in various directions within the cleaning tub .

[0079] That is, the second washing step is a step of washing tableware TW1 using washing water in at least a detergent-containing state out of a microbubble-containing state and a detergent-containing state. In this embodiment, the dishwasher 1 washes tableware TW1 in the second washing step using washing water in a microbubble-containing state and a detergent-containing state, as in the first washing step.

[0080] The controller C1 sets the upper limit temperature of the cleaning water in the second cleaning step as the second upper limit temperature TU2. The first upper limit temperature TU1 is lower than the second upper limit temperature TU2. Therefore, the controller C1 controls the heater 63 to raise the temperature of the cleaning water in the second cleaning step from that in the first cleaning step.

[0081] Heater 63 heats the wash water containing fine bubbles and detergent to a temperature above a first upper limit temperature TU1. When the temperature of the wash water exceeds the first upper limit temperature TU1 and rises to a second upper limit temperature TU2, controller C1 controls heater 63 so that the temperature of the wash water does not exceed the second upper limit temperature TU2 and so that the temperature decrease from the second upper limit temperature TU2 is within a temperature fluctuation range TD2. Then, controller C1 ends the second wash step after a predetermined required time has elapsed.

[0082] In this embodiment, for example, the second upper limit temperature TU2 is 60°C, the temperature fluctuation range TD2 is 5°C, and the time required for the second washing step is 30 minutes. The reason for setting the second upper limit temperature TU2 to 60°C is that proteins contained in dirt and the like adhering to the tableware TW1 tend to coagulate and harden at temperatures above 65°C, making it difficult for the cleaning effect of the microbubbles and detergent to be achieved.

[0083] In the second washing step, as in the first washing step, the fine bubbles contained in the washing water surround the tableware TW1 and adsorb to dirt and the like adhering to the tableware TW1, trapping the dirt and the like at the gas-liquid interface, and then peeling off from the tableware TW1 together with the trapped dirt and the like. The detergent contained in the washing water promotes the dissolution into the washing water of dirt and the like adhering to the tableware TW1 and dirt and the like trapped in the fine bubbles.

[0084] Next, the control unit C1 proceeds to step S103 and executes the draining process. The control unit C1 reversely rotates the pump 62 to drain the cleaning water containing fine bubbles and detergent, which is contaminated with dirt, out of the dishwasher 1 via the drain pipe P2.

[0085] Next, the control unit C1 proceeds to step S104 and executes the non-heated rinsing process. The control unit C1 controls the water supply electromagnetic valve 69 to open the water supply pipe P1 and supply water to the cleaning tank 7. At this time, the fine-bubble generator 10 makes the cleaning water stored in the water storage unit 71 contain fine bubbles.

[0086] When the control unit C1 determines, based on the detection signal from the water level sensor 34, that a sufficient amount of flush water has been stored in the water storage unit 71, it controls the water supply electromagnetic valve 69 to close the water supply pipe P1 and stop the supply of water to the washing tank 7. Then, the control unit C1 operates the pump 62.

[0087] In the non-heated rinsing step, water supplied from a water supply source (not shown) is used as cleaning water without being heated. For this reason, the control unit C1 stops the heater 63.

[0088] When the pump 62 rotates forward, the nozzle 61 sprays the washing water containing fine bubbles in various directions in the washing tank 7 to rinse the tableware TW1.

[0089] The fine bubbles contained in the washing water surround the tableware TW1, trapping residues and the like adhering to the surface of the tableware TW1, and then peeling off the trapped residues and the like from the tableware TW1.

[0090] Then, the control unit C1 ends the non-heated rinsing process when a preset required time has elapsed. In this embodiment, the required time for the non-heated rinsing process is 10 minutes, for example.

[0091] Next, the control unit C1 proceeds to step S105 and executes the draining process. The control unit C1 reversely rotates the pump 62 to drain the wash water containing fine bubbles and residue to the outside of the dishwasher 1 via the drain pipe P2.

[0092] Next, the control unit C1 proceeds to step S106 and executes the heated rinsing process. The control unit C1 controls the water supply electromagnetic valve 69 to open the water supply pipe P1 and supply water to the cleaning tank 7. At this time, the fine-bubble generator 10 makes the cleaning water stored in the water storage unit 71 contain fine bubbles.

[0093] When the control unit C1 determines, based on the detection signal from the water level sensor 34, that a sufficient amount of flush water has been stored in the water storage unit 71, it controls the water supply electromagnetic valve 69 to close the water supply pipe P1 and stop the supply of water to the washing tank 7. Then, the control unit C1 activates the pump 62 and heater 63.

[0094] As the pump 62 rotates forward, the nozzle 61 sprays the washing water containing fine bubbles in various directions in the washing tank 7 to rinse the tableware TW1. The effect of the fine bubbles contained in the washing water is the same as in the non-heated rinsing process.

[0095] The heater 63 heats the cleaning water containing fine bubbles from room temperature. The control section C1 sets the upper limit temperature of the cleaning water in the heated rinsing step as an upper limit rinsing temperature TU3.

[0096] When the temperature of the wash water rises to the upper limit rinsing temperature TU3, the control unit C1 controls the heater 63 so that the temperature of the wash water does not exceed the upper limit rinsing temperature TU3 and the temperature drop from the upper limit rinsing temperature TU3 is within the temperature fluctuation range TD3. Then, when a predetermined required time has elapsed, the control unit C1 ends the heating rinsing process.

[0097] In this embodiment, as an example, the upper rinsing temperature limit TU3 is 70° C., the temperature fluctuation range TD3 is 5° C., and the time required for the heating rinsing step is 20 minutes.

[0098] Next, control unit C1 proceeds to step S107 and executes the draining process. Control unit C1 reversely rotates pump 62 to drain the cleaning water containing fine bubbles and residue to the outside of dishwasher 1 via drain pipe P2.

[0099] Next, the control section C1 proceeds to step S108 to execute the drying step. The control section C1 operates the drying fan 68 and the heater 63 to send warm air into the washing tub 7, thereby drying the tableware TW1.

[0100] The heater 63 heats the air in the cleaning tank 7. The control unit C1 grasps the temperature of the air in the cleaning tank 7 based on the detection signal of the temperature sensor 31. The control unit C1 sets the upper limit temperature of the air in the cleaning tank 7 during the drying process as an upper limit drying temperature TU4.

[0101] When the temperature of the air in the cleaning tank 7 rises to the upper drying limit temperature TU4, the control unit C1 controls the heater 63 so that the temperature of the air in the cleaning tank 7 does not exceed the upper drying limit temperature TU4 and the temperature drop from the upper drying limit temperature TU4 is equal to or less than the temperature fluctuation range TD4. Then, when a predetermined required time has elapsed, the control unit C1 ends the drying process.

[0102] In this embodiment, as an example, the upper drying temperature limit TU4 is 60° C., the temperature fluctuation range TD4 is 10° C., and the time required for the drying process is 120 minutes.

[0103] After the drying step is completed, the control unit C1 stops the drying fan 68 and the heater 63, notifies the user of the completion of the cleaning operation, and then terminates this program.

[0104] <Action and effect> In the dishwasher 1 of the embodiment, in the first washing step of step S101, which uses washing water containing at least fine bubbles, the first upper limit temperature TU1 (40°C) is lower than the second upper limit temperature TU2 (60°C) for the second washing step of step S102. This allows the dishwasher 1 to prevent a decrease in the number of fine bubbles contained in the washing water in the first washing step, and as a result, can effectively maintain a state in which the cleaning effect of the fine bubbles is exerted.

[0105] Furthermore, in the second washing step of step S102, which uses wash water containing at least detergent, the second upper limit temperature TU2 (60°C) is higher than the first upper limit temperature TU1 (40°C) for the first washing step of step S101. This allows the dishwasher 1 to promote softening of dirt, oil, etc. adhering to the tableware TW1 in the second washing step, and promote dissolution or decomposition of dirt, etc. adhering to the tableware TW1 and dirt, etc. trapped in the fine bubbles, in the washing water, making it easier for the detergent to exert its cleaning effect.

[0106] Therefore, the dishwasher 1 of the embodiment can further improve the washing performance.

[0107] Furthermore, after performing the first washing step in step S101, the dishwasher 1 performs the second washing step in step S102. With this configuration, in the first washing step, the fine bubbles contained in the washing water surround the tableware TW1 and adsorb to dirt and other contaminants adhering to the tableware TW1, trapping the dirt and other contaminants at the gas-liquid interface, and then peeling them off from the tableware TW1 together with the trapped dirt and other contaminants. As a result, in the second washing step performed after the first washing step, dirt and other contaminants are more easily peeled off from the tableware TW1 than if only the second washing step were performed or if the first washing step were performed after the second washing step. As a result, the dishwasher 1 can further improve its washing performance.

[0108] Furthermore, in the second washing step, the dishwasher 1 washes the tableware TW1 using wash water containing both fine bubbles and detergent. With this configuration, in the second washing step, which is performed after the first washing step, the synergistic effect of the detergent and the fine bubbles makes it easier to remove dirt and other particles from the tableware TW1. As a result, the dishwasher 1 can further improve its washing performance. Furthermore, with this configuration, there is no need to provide a switching mechanism for switching between operating and stopping the fine-bubble generator 10 between the first washing step and the second washing step, thereby simplifying the system.

[0109] Furthermore, after performing the first washing step in step S101, the dishwasher 1 performs the second washing step in step S102 without draining the wash water. With this configuration, the low-temperature (40°C or less) wash water used in the first washing step can be heated in the second washing step to be used as high-temperature (60°C or less) wash water. As a result, the dishwasher 1 can save water and energy compared to a case in which the second washing step is performed after draining and supplying wash water after the first washing step.

[0110] Although the present invention has been described above with reference to the examples, it goes without saying that the present invention is not limited to the above examples and can be modified and applied as appropriate within the scope of the invention.

[0111] (Variation 1) In Figure 2, in the first washing process of step S101, no detergent is added, and tableware TW1 is washed using washing water containing fine bubbles, and when moving to the second washing process of step S102, the present invention also includes a configuration in which the second washing process is executed after the user adds additional detergent or after the automatic detergent adding mechanism is activated to automatically add detergent.

[0112] (Variation 2) 2, the present invention also includes a configuration in which a draining step similar to steps S103, S105, and S107 is executed between the first washing step of step S101 and the second washing step of step S102. In this case, when transitioning from the draining step to the second washing step, the user may add additional detergent or the automatic detergent dispensing mechanism may be activated to automatically dispense detergent, and then water will be supplied in the second washing step.

[0113] (Variation 3) 2, the present invention also includes a configuration in which the order of the first washing step in step S101 and the second washing step in step S102 is reversed, and water is supplied and detergent is added in the second washing step. In this case, when transitioning from the second washing step to the first washing step, some of the high-temperature washing water may be drained and then room-temperature water may be supplementarily supplied, thereby lowering the temperature of the washing water containing fine bubbles and detergent to below the first upper limit temperature TU1. In this case, after performing a drainage step between the second washing step and the first washing step, detergent may be added as needed and water may be supplied in the first washing step, thereby heating the washing water containing at least fine bubbles from room temperature.

[0114] (Variation 4) 1, the present invention also includes a configuration in which a bypass pipe that bypasses the micro-bubble generator 10 is provided between the following portion and the downstream end of the water supply pipe P1, and a switching solenoid valve is provided that switches between a state in which water flowing through the water supply pipe P1 passes through the micro-bubble generator 10 but not through the bypass pipe, and a state in which water flowing through the water supply pipe P1 passes through the bypass pipe but not through the micro-bubble generator 10, and the controller C1 controls the switching solenoid valve. In this case, in the second washing step, washing water containing detergent, or washing water containing microbubbles and detergent, can be used as needed. In this case, washing water that does not contain microbubbles can be used in the unheated rinsing step and the heated rinsing step.

[0115] (Variation 5) In FIG. 1, the present invention also includes a configuration in which the micro-bubble generator 10 is relocated from between the following portion and the downstream end of the water supply pipe P1 to between the jet outlet 62A of the pump 62 and the nozzle 61.

[0116] (Variation 6) 2, the present invention also includes a configuration in which, when the temperature of the cleaning water rises from room temperature to the first upper limit temperature TU1 in the first cleaning step of step S101, the first cleaning step is terminated and the second cleaning step of step S102 is subsequently executed. In this case, the required time for the first cleaning step is not set in advance, and the required time is the time from when the first cleaning step starts until the temperature of the cleaning water reaches the first upper limit temperature TU1. [Industrial Applicability]

[0117] The present invention can be used in, for example, a dishwasher or a dish washer-dryer. [Explanation of symbols]

[0118] 1. Dishwasher TW1…Objects to be washed (tableware) 10...Fine bubble generator TU1…1st upper limit temperature TU2…Second upper limit temperature

Claims

1. A dishwasher equipped with a microbubble generator that adds microbubbles to the washing water used to wash items, The state in which the cleaning water contains the microbubbles is referred to as a microbubble-containing state, The state in which the cleaning water contains a detergent is referred to as a detergent-containing state, a first washing step of washing the object using the washing water in at least the microbubble-containing state out of the microbubble-containing state and the detergent-containing state; a second cleaning step of cleaning the object using the cleaning water in at least the detergent-containing state out of the microbubble-containing state and the detergent-containing state; configured to run A dishwasher characterized in that a first upper limit temperature, which is an upper limit temperature of the washing water in the first washing step, is lower than a second upper limit temperature, which is an upper limit temperature of the washing water in the second washing step.

2. 2. The dishwasher according to claim 1, wherein the second washing step is carried out after the first washing step.

3. 3. The dishwasher according to claim 2, wherein in the second washing step, the objects are washed using the washing water containing the fine bubbles and the detergent.

4. 4. The dishwasher according to claim 2, wherein the second washing step is carried out without draining the washing water after the first washing step.

Images