Dishwasher

Abstract

To provide a dishwasher capable of suppressing reduction in water level detection accuracy due to malfunction of a water level detection means by executing a process for periodically washing the water level detection means.SOLUTION: The washing machine includes a housing, a washing tub disposed inside the housing and configured to accommodate an object to be washed therein such that the object can be taken in and out, a water supply unit configured to supply water to the inside of the washing tub from the outside, a water level detection unit configured to detect a water level of the water supplied from the outside via the water supply unit, a washing unit configured to wash and rinse the object to be washed in a washing operation including a washing process and a rinsing process using the water supplied to the inside of the washing tub, a drainage unit configured to drain water from the inside of the washing tub, and a control unit configured to control a washing operation of the washing unit and an operation of the drainage unit. The control means counts the number of execution times of the washing operation, and performs the washing process of the water level detection means when the number of execution times of the washing operation exceeds N times which is a preset prescribed number of times.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to cleaning of a water level detection means of a dishwasher that washes dishes. [Background technology]

[0002] Conventional dishwashers for washing dishes supply water to a washing tank from the outside, and when a predetermined amount of water has accumulated, the water is used to wash the dishes, and are equipped with a water level detection means for detecting when the predetermined amount of water has accumulated in the washing tank.

[0003] A known water level detection means is one that detects the water level by raising a float using water supplied to a cleaning tank for cleaning or rinsing, thereby detecting that a predetermined amount of water has been supplied (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-113106 Summary of the Invention [Problem to be solved by the invention]

[0005] When washing dishes in a dishwasher, it is desirable to remove as much residue and food particles as possible from the dishes, but because this is time-consuming, they are often placed in the dishwasher as is. Residue and food particles of a certain size will be captured by the filter, but small particles will slip through the filter.

[0006] In the conventional dishwasher disclosed in Patent Document 1, a water level detection means is provided in the drainage path, and water sent from the drainage means flows in from below the float of the water level detection means and is discharged from above. Because the water level detection means is provided in the drainage path, fine residue and food debris that slips through the filter enters the drainage path and passes through the water level detection means, which can cause the fine residue and food debris to adhere to the float of the water level detection means, or oil washed off the dishes to adhere to it, which can cause the float to malfunction.

[0007] In the conventional dishwasher disclosed in Patent Document 1, blades are provided on the underside of the float of the water level detection means, and a water flow is directed against the blades to rotate the float, thereby preventing the accumulation of residue, food debris, oil, etc. on the float, etc. However, the water flow alone during the normal washing process of the items being washed is not sufficient to prevent the adhesion and accumulation of fine residue, food debris, oil, etc. on the float, etc., and malfunction of the float may occur.

[0008] The present disclosure aims to solve the above-mentioned problems and to provide a dishwasher that can prevent a decrease in water level detection accuracy due to malfunction of the water level detection means by periodically performing a process of cleaning the water level detection means. [Means for solving the problem]

[0009] The dishwasher according to the present disclosure comprises a housing, a washing tub arranged inside the housing and accommodating items to be washed therein so that they can be easily removed and put in, a water supply means for supplying water into the washing tub from the outside, a water level detection means for detecting the level of water supplied from the outside via the water supply means and used in the washing and rinsing processes of the items to be washed, a washing means for using the water supplied into the washing tub to wash and rinse the items to be washed in a washing operation including the washing and rinsing processes of the items to be washed, a drainage means for draining the water supplied into the washing tub from the washing tub, and a control means for controlling the washing operation of the washing means and the operation of the drainage means, wherein the control means counts the number of times the washing operation is performed, and when the number of times the washing operation is performed exceeds a predetermined number N, the water level detection means performs the washing process. [Effects of the Invention]

[0010] In the dishwasher according to the present disclosure, the number of times the wash operation is performed is counted, and when the number of times the wash operation is performed exceeds a preset number N, a cleaning process for the water level detection means is performed. This allows the water level detection means to be cleaned periodically, washing away fine residue, food particles, oil, etc. around the water level detection float, preventing the float from malfunctioning and maintaining the accuracy of water level detection. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an external perspective view showing an example of a state in which a washing tub is pulled out from a housing of a dishwasher according to a first embodiment of the present disclosure. FIG. [Figure 2] 1 is a schematic cross-sectional view showing a cross section of a dishwasher according to a first embodiment of the present disclosure cut in the front-rear direction and viewed from the side. [Figure 3] 2 is a cross-sectional view of a water level detection means of the dishwasher according to the first embodiment of the present disclosure. FIG. [Figure 4] 4 is a flowchart of a process for washing an object to be washed, including washing with a water level detection means, of the dishwasher according to the first embodiment of the present disclosure. [Figure 5]10 is a flowchart of a water level detection means cleaning process when a water supply abnormality occurs during a washing process in the dishwasher according to the first embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiment 1 A dishwasher 100 according to an embodiment of the present disclosure will be described below with reference to the drawings. Note that in the following drawings, including Figure 1, the relative dimensional relationships and shapes of the components may differ from the actual ones. In the following drawings, the same reference numerals denote the same or equivalent components, and this applies throughout the entire specification.

[0013] Embodiment 1 Fig. 1 is an external perspective view showing an example of a dishwasher according to embodiment 1 of the present disclosure when the washing tub is pulled out from the housing, and Fig. 2 is a schematic cross-sectional view showing a cross section of the dishwasher according to embodiment 1 of the present disclosure cut in the front-to-rear direction from the side. The configuration of each part of dishwasher 100 will be described with reference to Figs. 1 and 2.

[0014] The front-to-back, left-to-right, and up-to-down directions shown in Figure 1 are the basic directions, and when front-to-back, left-to-right, and up-to-down directions are illustrated in subsequent drawings, they shall be the same directions as the basic directions shown in Figure 1.

[0015] [Dishwasher 100] Dishwasher 100 according to embodiment 1 of the present invention is a dishwasher that is incorporated into, for example, kitchen furniture (system kitchen) (not shown). As shown in Fig. 1, dishwasher 100 has a housing 1 that forms the outer shell of dishwasher 100, and a washing tub 3 housed inside housing 1.

[0016] The dishwasher 100 also includes a cover 5 that is provided on the top surface of the washing tub 2 and opens and closes a washing tub opening 2a on the top surface of the washing tub 2, and a door 6 that is attached to the front of the washing tub 2 and opens and closes when the washing tub 2 housed inside the housing 1 is pulled out. The dishwasher 100 also includes a control unit 15 in the space between the front of the washing tub 2 and the door 6 that controls the operation of the dishwasher 100.

[0017] (Housing) The housing 1 is formed in a box shape, and a housing opening 1a is formed on the front side of the housing 1. The housing 1 is formed into a box shape by, for example, bending a metal plate. The housing opening 1a is an opening that penetrates the front side of the housing 1, and this housing opening 1a is closed by a door body 6.

[0018] The cleaning tank 2 passes through this housing opening 1a to be stored inside the housing 1 and to be pulled out from the housing 1. The housing 1 and the cleaning tank 2 are slidably connected by slide rails (not shown), and the slide rails enable the cleaning tank 2 to be smoothly stored in the housing 1 and pulled out from the housing 1.

[0019] A water supply valve 11 is provided inside the housing 1. The water supply valve 11 is a valve that supplies water used for cleaning or rinsing from outside the housing 1 into the cleaning tank 2 via a water supply hose 16, and also stops the supply of water used for cleaning or rinsing into the cleaning tank 2.

[0020] (Cleaning tank) The washing tub 2 is formed in a box shape, and a washing tub opening 2a is formed on the top surface of the washing tub 2. The washing tub opening 2a is an opening formed on the top surface of the washing tub 2, and a user can store tableware 10 such as plates and bowls in a dish basket 16 arranged inside the washing tub 2 as shown in Figure 2, and can also remove tableware 10 from inside the washing tub 2 through the washing tub opening 2a.

[0021] The cleaning tank 2 is provided with a water level detection device 7 (described in detail later), which is a water level detection means of the present disclosure that detects the water level of the water used for cleaning or rinsing stored in the cleaning tank 2, a water temperature detection device 14 that detects the temperature of the water used for cleaning or rinsing and is provided in the cleaning tank recess 2b, which is a recessed portion at the bottom of the cleaning tank 2, and a heater 3 that heats the water used for cleaning or rinsing.

[0022] In addition, washing pump 12, which pressurizes the water used for washing or rinsing and supplies it to washing nozzle 13, is provided on the outside of the bottom of washing tub 2. As described above, the water used for washing or rinsing, which has been pressurized by washing pump 12, is supplied to washing nozzle 13. Washing nozzle 13 is located below dish basket 16.

[0023] The cleaning nozzle 13 has a space inside through which the water used for cleaning or rinsing passes, and is made of, for example, a resin material. The cleaning nozzle 13 also has a plurality of spray holes (not shown), through which the water used for cleaning or rinsing, which is pressurized and supplied from the cleaning pump 12, is sprayed.

[0024] The washing nozzle 13 is rotatably supported by a shaft 13a. When the water used for washing or rinsing, which is pressurized and sent from the washing pump 12, passes through the inside of the shaft 13a and reaches the washing nozzle 13, the washing nozzle 13 rotates in the direction opposite to the direction of spraying due to the reaction force of the water used for washing or rinsing, which is sprayed from one of the multiple spray holes (not shown) that sprays in the lateral direction. As the washing nozzle 13 rotates, the water used for washing or rinsing is sprayed from the spray holes toward the tableware 10, thereby washing or rinsing the tableware 10.

[0025] Similarly to the cleaning pump 12, a drain pump 8 is provided on the outside of the bottom of the cleaning tank 2. The drain pump 8 drains the water used for cleaning or rinsing that is stored in the cleaning tank 2 out of the cleaning tank 2 via a drain pipe 9.

[0026] (lid) The lid 5 is provided so as to be able to open and close the cleaning tank opening 2a formed in the upper part of the cleaning tank 2, and in the closed state, separates the inside and outside of the cleaning tank 2. The lid 5 is provided on the upper part of the inner surface of the housing 1. One end of a link mechanism (not shown) is attached to the lid 5, and the other end of the link mechanism is attached to the upper part of the inner surface of the housing 1.

[0027] This link mechanism causes the lid body 5 to be lifted up to open the cleaning tank opening 2a of the cleaning tank 2 when the cleaning tank 2 is pulled out of the housing 1, and to be lowered to close the cleaning tank opening 2a of the cleaning tank 2 when the cleaning tank 2 is stored in the housing 1. The link mechanism also prevents the lid body 5 from being pulled out of the housing 1 together with the cleaning tank 2 when the cleaning tank 2 is pulled out of the housing 1; in other words, the lid body 5 is configured to remain within the housing 1.

[0028] (Door body) As shown in Figures 1 and 2, a door 6 is provided on the front side of the dishwasher 100. The door 6 is attached to the front of the washing tub 2 and covers the housing opening 1a of the housing 1. A handle 6a is provided on the top of the door 6 to be used when pulling the washing tub 2 out from the housing 1 to the front.

[0029] In addition, an operation unit (not shown) is provided on door body 6. The operation unit receives operation instructions input by the user and outputs corresponding operation signals to control unit 15. The operation unit is provided with a power switch for turning on the dishwasher 100 and an operation switch for starting or pausing the operation of dishwasher 100.

[0030] (control unit) Although not shown, control unit 15 may be, for example, dedicated hardware, or a circuit board mounted with a CPU (also called a central processing unit, processing device, arithmetic unit, microprocessor, microcomputer, or processor) that executes programs stored in a storage unit, housed in a case. Control unit 15 controls the operation of each device that constitutes dishwasher 100, and is the control means of dishwasher 100 according to the embodiment of the present disclosure.

[0031] The control unit 15 receives information detected by the water level detection device 7 and the water temperature detection device 14. The control unit 15 controls the water supply valve 11, the wash pump 12, the heater 3, the drain pump 8, and the like.

[0032] (Water level detection device) As shown in Figure 2, the water level detection device 7 is located in the space between the door body 6 and the cleaning tank 2, and is provided in the drainage path, more specifically, on the downstream side (where the water flows) of the drainage pump 8. When the water used for cleaning or rinsing is drained, the water sent out from the drainage pump 8 passes through the water level detection device 7 and is drained out of the cleaning tank 2 via the drainage pipe 9.

[0033] To start washing or rinsing, water for washing or rinsing must be stored in the washing tank 2, and the water level detection device 7 is provided to store this water up to a predetermined amount. When water for washing or rinsing is stored in the washing tank 2, the water that flows into the water level detection device 7 passes through a drainage pump 8 that is not operating and flows into the inside from a water supply pipe section 76 formed in a water level detection device case 71 that constitutes the water level detection device 7 shown in Figure 3.

[0034] When water flows into the water level detection device 7, a float 73 disposed inside the water level detection device 7 begins to rise due to the buoyancy caused by the water pushing up the float 73. Although the entire float 73 is not shown, it has a thick circular shape with a float guide hole 73a, which is a circular hole that runs through the thickness of the float 73 at its center, giving it a doughnut shape, and is made of foamed resin or the like that has a specific gravity lower than that of water. In addition, although not shown in its entirety, a doughnut-shaped magnet 78 is disposed on the inner periphery of the float 73, and the magnet 78 rises together with the float 73 due to the buoyancy caused by the water pushing up the magnet 78.

[0035] The float 73 is located inside the water level detection device 7 and is provided in a detector holding tube 75 that is cylindrical and extends vertically, and is movable vertically through a float guide hole 73a, which is a through-hole. Naturally, the donut-shaped magnet 78 also has a through-hole, and the detector holding tube 75 passes through the magnet 78 as well.

[0036] The cylindrical detector holding tube 75 is provided on the water level detection device cover 72 that constitutes the water level detection device 7, and as mentioned above, is cylindrical and hollow with a space inside, and the detector 74 is arranged in that internal space.

[0037] The detector 74 is an element that responds to magnetism, for example, an electromechanical switch that operates by applying magnetism such as a reed switch. The magnet 78 arranged on the inner circumference of the float 73 rises together with the float 73 due to the buoyancy caused by the water, and when it rises to a position where the magnetism is applied to the detector 74, a signal is sent from the detector 74 to the control unit 15, indicating that the water required for cleaning or rinsing has accumulated inside the cleaning tank 2 up to the specified amount, and the control unit 15 closes the water supply valve 11 and stops the water supply.

[0038] (Washing and rinsing operations) When the water supply is completed, the dishwashing operation for the tableware 10 begins, and the control unit 15 drives the washing pump 12 to wash the tableware 10. Note that washing refers to the process of pumping water containing detergent stored in the washing tank 2 with the washing pump 12 to send it to the washing nozzle 13, and then spraying the water containing detergent onto the tableware 10 from a spray hole (not shown) of the washing nozzle 13 to wash the tableware 10.

[0039] During washing, in order to raise the water temperature to a temperature at which the enzymes contained in the detergent used to wash away dirt can easily work, for example, 60°C, the control unit 15 drives the washing pump 12 and turns on (operates) the heater 3 shown in Figure 2 to heat the water.

[0040] The water temperature is detected by a water temperature detection device 14 shown in Figure 2, which sends information (signal) about the detected temperature to a control unit 15. Based on the information about the water temperature detected by the water temperature detection device 14, the control unit 15 adjusts the water temperature by turning the heater 3 ON (operating) or OFF (stopping) so that the water temperature becomes a temperature at which the enzymes can easily work, for example, 60°C.

[0041] After the wash pump 12 and heater 3 have been turned on (operated) for a predetermined time, the control unit 15 turns off (stops) the wash pump 12 and heater 3, and then turns on (operates) the drain pump 8 to drain the water containing the detergent used for washing. The drainage water after washing not only contains the detergent used for washing, but also food residue and oil that has been removed from the tableware 10 by washing.

[0042] Food debris of a certain size is captured by the residue filter 4, which is attached to cover the washing tank recess 2b and has a mesh or punched holes that allow water to pass through, but small food debris can slip through the mesh or punched holes and end up in the drainage path. Naturally, oil also passes through the residue filter 4.

[0043] Water containing small food particles and oil is drawn from washing tank recess 2b to drain pump 8 connected by connecting pipe 8a, and sent from drain pump 8 to water level detection device 7 connected by connecting pipe 8b. As shown in Figure 3, the water sent from drain pump 8 flows into water level detection device 7 from water supply pipe section 76 formed in water level detection device case 71 that constitutes water level detection device 7, passes through the space in which float 73 is located, and is drained out of washing tank 2 via drain pipe 9 from drain pipe section 77 provided in water level detection device cover 72 that extends to below water level detection device case 71.

[0044] After the drain pump 8 is turned on (operated) for a predetermined time to drain water containing small food particles and oil, the control unit 15 opens the water supply valve 11 to supply water for rinsing to the washing tank 2.

[0045] Rinse water is supplied to the cleaning tank 2, and when the water level detection device 7 detects that the water required for rinsing has accumulated inside the cleaning tank 2 up to a predetermined amount, the control unit 15 closes the water supply valve 11 to stop the water supply.

[0046] Thereafter, the control unit 15 turns on (operates) the washing pump 12 to start rinsing. Rinsing is performed multiple times, for example, three times: rinse 1, rinse 2, and a final rinse. Rinse 1 is intended to wash away any detergent components remaining on the dishes 10 or in the washing tub 2, and does not raise the water temperature, so the heater 3 is not turned on (operated).

[0047] The control unit 15 turns on (operates) the cleaning pump 12 for a predetermined time, then turns off (stops) the cleaning pump 12, and then turns on (operates) the drain pump 8 for a predetermined time to drain the water used in rinse 1.

[0048] When drainage of rinse 1 is completed, control unit 15 opens water supply valve 11 to supply water for rinse 2 to cleaning tub 2. Water for rinse 2 is supplied to cleaning tub 2, and when water level detection device 7 detects that the water required for rinse 2 has accumulated inside cleaning tub 2 up to a predetermined amount, control unit 15 closes water supply valve 11 and stops the water supply.

[0049] Thereafter, the control unit 15 turns on (operates) the washing pump 12 to start rinse 2. Like rinse 1, rinse 2 aims to flush away any detergent components remaining on the dishes 10 or in the washing tank 2, and does not raise the water temperature, so the heater 3 is not turned on (operates).

[0050] The control unit 15 turns on (operates) the cleaning pump 12 for a predetermined time, then turns off (stops) the cleaning pump 12, and then turns on (operates) the drain pump 8 for a predetermined time to drain the water used in rinse 2.

[0051] When the drainage of rinse 2 is completed, control unit 15 opens water supply valve 11 to supply water for the final rinse to cleaning tank 2. When water for the final rinse is supplied to cleaning tank 2 and water level detection device 7 detects that the water required for the final rinse has accumulated inside cleaning tank 2 up to a predetermined amount, control unit 15 closes water supply valve 11 and stops the water supply.

[0052] Thereafter, the control unit 15 turns on (operates) the wash pump 12 to start the final rinse. Unlike rinse 1 and rinse 2, the final rinse serves both as a rinse and as a sterilization of the tableware 10, and therefore the water temperature must be raised to a temperature that is effective for sterilization, for example, 80°C, so the heater 3 is turned on (operates) to start heating the water.

[0053] The water temperature is detected by a water temperature detection device 14 shown in Figure 2, which sends information (signal) about the detected temperature to a control unit 15. Based on the information about the water temperature detected by the water temperature detection device 14, the control unit 15 adjusts the water temperature by turning the heater 3 ON (operating) or OFF (stopping) so that the water temperature reaches a temperature that is effective for sterilization, for example, 80°C.

[0054] After the cleaning pump 12 and heater 3 are turned on (operated) for a predetermined time, the control unit 15 turns off (stops) the cleaning pump 12 and heater 3, and then turns on (operates) the drain pump 8 to drain the water used for the final rinse.

[0055] In this description, the number of rinses is three, but this is just an example and the number may be two or four. Also, although the rinse with increased water temperature is described as being performed once as the final rinse out of the three rinses, the rinse with increased water temperature may be performed multiple times.

[0056] As mentioned above, when washing and rinsing are performed, small food particles and water containing oil pass through the water level detection device 7. Therefore, as the dishwasher 100 is used more frequently, foreign matter may accumulate on the float 73, such as small food particles adhering to the float 73 or oil particles sticking to the float 73.

[0057] Therefore, the dishwasher 100 according to the embodiment of the present disclosure is provided with a cleaning process for the water level detection device 7 to wash away any food debris or oil that has adhered, or to prevent food debris from adhering or oil from sticking.

[0058] (Cleaning process of water level detection device 7) Next, the operation of the washing process and rinsing process of the object to be washed of the dishwasher 100 according to the embodiment of the present disclosure, and the washing process of the water level detection device 7 incorporated therein, will be described with reference to Figures 4 and 5. Figure 4 is a flowchart of the washing process of the object to be washed, including washing by the water level detection means of the dishwasher according to the embodiment 1 of the present disclosure, and Figure 5 is a flowchart of washing by the water level detection means when there is a water supply abnormality during the washing process of the dishwasher according to the embodiment 1 of the present disclosure.

[0059] First, when a cleaning start switch on an operation unit (not shown) is operated, the control unit 15 starts the cleaning process step S1 of the cleaning operation as shown in Fig. 4. When S1 starts, the control unit 15 opens the water supply valve 11 in water supply step S11 to start water supply as shown in Fig. 5. In addition, the heater 3 is turned ON (operated) to heat the supplied water.

[0060] The supplied water accumulates from the washing tank recess 2b, which is the lowest layer of the washing tank 2. Therefore, under normal water supply conditions, the water temperature detection device 14 and heater 3 are submerged early, and the water temperature detection device 14 does not detect a high temperature. Therefore, normally, an abnormal temperature is not detected within the predetermined time Ti1 in step S12. The predetermined time Ti1 here is the time it takes for the water supplied into the washing tank 2 to reach a predetermined water level at which washing or rinsing is possible.

[0061] In step S12, a timing means (not shown) provided in the control unit 15 measures the time required for a predetermined amount of water required for cleaning to accumulate inside the cleaning tank 2. The time required for the predetermined amount of water required for cleaning to accumulate inside the cleaning tank 2 is stored in the control unit 15 as a preset predetermined time.

[0062] For example, if the predetermined time from when water supply valve 11 is opened and water supply begins until detector 74 of water level detection device 7 detects that a predetermined amount of water has accumulated inside cleaning tank 2 is set to, for example, 3 minutes (predetermined time Ti1 in the present disclosure), if detector 74 of water level detection device 7 detects within 3 minutes, control unit unit 15 will determine that it is operating normally, close water supply valve 11, and end water supply. Note that although 3 minutes has been described here, the time is not limited to this and may be 5 minutes or 4 minutes, and is set as appropriate.

[0063] If the water supply valve 11 is open but the main water valve is closed, water will not be supplied to the washing tank 2. Since the heater 3 is also ON (operating) without water being supplied, the washing tank 2 will be in a dry-run state without being submerged. The water temperature detection device 14 can also detect the ambient air temperature, so the ambient temperature around the heater 3, which is in a dry-run state without being submerged and is therefore high, for example, exceeding 100°C, will also be high.

[0064] If water temperature detection device 14 detects such a high temperature, exceeding the abnormal (empty-baking) temperature Te4, within a predetermined time Ti1, control unit 15 turns off (stops) heater 3 and closes water supply valve 11 to alert the user to the abnormal condition. The alert may be provided by displaying a message on a display unit (not shown) of dishwasher 100, or by sound or a buzzer. Because the water temperature never exceeds 100°C during normal operation of dishwasher 100, 100°C is described here as the abnormal (empty-baking) temperature Te4. If water temperature detection device 14 detects a temperature exceeding Te4, 100°C, the device immediately shuts down the device for product safety reasons.

[0065] As described above, water normally supplied to the cleaning tank 2 passes through the drain pump 8, which is not in operation, and flows into the interior through the water supply pipe 76 formed in the water level detection device case 71 that constitutes the water level detection device 7. The water that flows into the interior of the water level detection device 7 causes the float 73 disposed inside the water level detection device 7 and the magnet 78 disposed on the inner periphery of the float 73 to rise due to the buoyancy caused by the water pushing up.

[0066] When the detector 74 rises to a position where the magnetism of the magnet 78 is applied to it, it is determined that the water required for cleaning has accumulated inside the cleaning tank 2 up to the specified amount, and a signal is sent from the detector 74 to the control unit 15 in step S13, and the control unit 15 closes the water supply valve 11 in step S14 to end the water supply.

[0067] Once the water supply is completed, the process proceeds to step S15, where the dishwashing operation for the tableware 10 is performed. The control unit 15 drives the washing pump 12, and pressurized water is supplied by the washing pump 12 to the washing nozzle 13, which is rotatably supported on a shaft 13a that is in water-permeable communication with the washing pump 12, and sprayed from multiple spray holes (not shown) formed in the washing nozzle 13.

[0068] The washing nozzle 13 rotates in the opposite direction to the direction of spraying due to the reaction force of the water sprayed from the injection hole that sprays in the side direction (not shown), so that water is sprayed toward the tableware 10 while the washing nozzle 13 rotates, thereby cleaning the tableware 10.

[0069] As mentioned above, during washing, in order to raise the water temperature to a temperature at which the enzymes contained in the detergent used to wash away dirt can easily work, for example, 60°C (the water temperature Te1 disclosed in this specification), the control unit 15 drives the washing pump 12 and turns on (operates) the heater 3 shown in Figure 2 to heat the water.

[0070] As mentioned above, the water temperature is detected by the water temperature detection device 14 shown in Fig. 2, and information (signal) on the detected temperature is sent to the control unit 15. Based on the information on the water temperature detected by the water temperature detection device 14, the control unit 15 adjusts the water temperature by turning the heater 3 ON (operating) or OFF (stopping) so that the water temperature becomes a temperature at which the enzymes can easily function, for example, 60°C.

[0071] After the wash pump 12 and heater 3 have been turned on (operated) for a predetermined time, the control unit 15 turns off (stops) the wash pump 12 and heater 3, and then turns on (operates) the drain pump 8 to drain water containing the detergent used for washing and food residue and oil removed from the tableware 10. When drainage is complete, the washing process step S1 ends.

[0072] In step S13, a timing means (not shown) provided in the control unit 15 measures the time required for a predetermined amount of water required for cleaning to accumulate inside the cleaning tank 2. As described above, the time required for a predetermined amount of water required for cleaning to accumulate inside the cleaning tank 2 is stored in the control unit 15 as a preset predetermined time.

[0073] As mentioned above, if the predetermined time from when water supply valve 11 is opened and water supply begins until detector 74 of water level detection device 7 detects that a predetermined amount of water has accumulated inside cleaning tank 2 is set to, for example, 3 minutes (predetermined time Ti1 in the present disclosure), if detector 74 of water level detection device 7 detects within 3 minutes, control unit unit 15 determines that the device is operating normally, closes water supply valve 11, and ends water supply. Note that although 3 minutes has been described here, the time is not limited to this and may be 5 minutes or 4 minutes, and is set as appropriate.

[0074] In step S13, if the detector 74 of the water level detection device 7 does not detect anything within three minutes, which is set as an example of a predetermined time in the description of the dishwasher 100 according to embodiment 1 of the present disclosure, the control unit 15 determines that there is an abnormality in the water supply.

[0075] One of the abnormalities related to the water supply is the inflow of water containing small food particles or oil into the water level detection device 7, as mentioned above, which may accumulate and hinder the movement and rise of the float 73 of the water level detection device 7. In this case, water is being supplied to the washing tank 2, but the water level cannot be detected, so since there is water in the washing tank 2, this water is used to carry out a process to remove the factors that hinder the movement and rise of the float 73. The process of removing the factors that hinder the movement and rise of the float 73 referred to here is the process of cleaning the water level detection device 7, or more specifically, the process of cleaning the float 73, the interior of the water level detection device 7 through which the water passes.

[0076] In step S31 of heating the wash water shown in Figure 5, the water in the wash tank 2 is heated by the heater 3. In the washing process of the water level detection device 7, the water temperature is raised to Te3 to remove and wash away accumulated food residue and oil. Te3 can be set within the range of Te1, which is the water temperature during washing (60°C), but not boiling (100°C), or Te2, which is the water temperature during the final rinse (80°C), as described below, but not boiling (100°C), to make it easier to remove and wash away accumulated food residue and oil.

[0077] In step S31 for heating wash water, the water temperature is raised to Te3, and when the water temperature detection device 14 detects the water temperature Te3, the process proceeds to the next step S32, where the drain pump 8 is turned ON (operated) to drain the water. Note that although it has been described here that the drain operation is performed when the water temperature detection device 14 detects the water temperature Te3, that is, when the water temperature reaches Te3, the drain operation may not be performed immediately even when the water temperature detection device 14 detects the water temperature Te3, but the drain operation may be performed after the water temperature detection device 14 has maintained the state for a predetermined time Ti4, for example, five minutes, even after detecting the water temperature Te3.

[0078] When the drain pump 8 is turned on (operated), water is drawn from the cleaning tank recess 2b to the drain pump 8 connected by the connecting pipe 8a, flows from the drain pump 8 into the inside of the water level detection device 7 connected by the connecting pipe 8b, passes through the space where the float 73 is located, and is drained out of the cleaning tank 2 via the drain pipe part 77 and the drain pipe 9. By carrying out the cleaning process for the water level detection device in this way, the possibility of improving the malfunction of the water level detection device can be increased.

[0079] Once drainage is complete, the process restarts from step S11 of supplying water, and if cleaning is successful, the cleaning process S1 ends. Once S1 ends, the process moves to the next step S2, the rinsing process 1. When the rinsing process 1 begins, the control unit 15 opens the water supply valve 11 to supply rinsing water to the cleaning tub 2, and when the water level detection device 7 detects that the water required for rinsing has accumulated inside the cleaning tub 2 up to a predetermined amount, the control unit 15 closes the water supply valve 11 to end the water supply.

[0080] Thereafter, the control unit 15 turns on (operates) the washing pump 12 to start rinse 1. The purpose of rinse 1 is to flush away any detergent components remaining on the dishes 10 or in the washing tank 2, and the water temperature is not increased, so the heater 3 is not turned on (operated).

[0081] The control unit 15 turns on (operates) the cleaning pump 12 for a predetermined time, then turns off (stops) the cleaning pump 12, and then turns on (operates) the drain pump 8 for a predetermined time to drain the water used in rinse 1.

[0082] When the drainage of rinse 1 is complete, step S2 rinse 1 process is completed and the process moves to the next step S3 rinse 2 process. To supply water for rinse 2 to cleaning tank 2, control unit 15 opens water supply valve 11. When water for rinse 2 is supplied to cleaning tank 2 and water level detection device 7 detects that the water required for rinse 2 has accumulated inside cleaning tank 2 up to a predetermined amount, control unit 15 closes water supply valve 11 and ends the water supply.

[0083] Thereafter, the control unit 15 turns on (operates) the washing pump 12 to start rinse 2. Like rinse 1, rinse 2 aims to flush away any detergent components remaining on the dishes 10 or in the washing tank 2, and does not raise the water temperature, so the heater 3 is not turned on (operates).

[0084] The control unit 15 turns on (operates) the cleaning pump 12 for a predetermined time, then turns off (stops) the cleaning pump 12, and then turns on (operates) the drain pump 8 for a predetermined time to drain the water used in rinse 2.

[0085] When the drainage of rinse 2 is completed, the rinse 2 process in step S3 is completed, and the process moves to the next step S4, the final rinse process. To supply water for the final rinse to the cleaning tank 2, the control unit 15 opens the water supply valve 11. When the water for the final rinse is supplied to the cleaning tank 2 and the water level detection device 7 detects that the water required for the final rinse has accumulated inside the cleaning tank 2 up to the specified amount, the control unit 15 closes the water supply valve 11 and ends the water supply.

[0086] Thereafter, the control unit 15 turns on (operates) the wash pump 12 to start the final rinse. Unlike rinses 1 and 2, the final rinse serves both as a rinse and as a sterilization of the tableware 10, and therefore the water temperature must be raised to a temperature that is effective for sterilization, for example, 80°C (water temperature Te2 in the present disclosure), so the heater 3 is turned on (operates) to start heating the water.

[0087] As mentioned above, the water temperature is detected by the water temperature detection device 14, and the control unit 15 adjusts the water temperature based on the information on the water temperature detected by the water temperature detection device 14 by turning the heater 3 ON (operating) or OFF (stopping) so that the water temperature reaches 80°C (the water temperature Te2 disclosed in this specification), which is a temperature that has a disinfecting effect.

[0088] After the cleaning pump 12 and heater 3 are turned on (operated) for a predetermined time, the control unit 15 turns off (stops) the cleaning pump 12 and heater 3, and then turns on (operates) the drain pump 8 to drain the water used for the final rinse.

[0089] The control unit 15 counts the number of times the cleaning operation has been performed, and stores information about the number of times the cleaning operation has been performed in a memory (not shown) provided in the control unit 15. Then, in step S5, the control unit 15 compares whether the number of times the cleaning operation has been performed exceeds a preset number N. If the control unit 15 determines in step S5 that the number of times the cleaning operation has been performed does not exceed the preset number N, the process proceeds to the next step S6, which is a drying step.

[0090] In the drying step, in order to dry the tableware 10 and the inside of the washing tank 2, the control unit 15 turns on (operates) an air blower fan (not shown) that draws in drying air from outside the washing tank 2 and blows it into the washing tank 2. The control unit 15 also turns on (operates) a drying heater (not shown) that heats the drying air, thereby drying the tableware 10 and the inside of the washing tank 2.

[0091] After the control unit 15 turns on (operates) the blower fan and the drying heater for a predetermined time, the control unit 15 turns off (stops) the blower fan and the drying heater to end the drying process in step S6, and then proceeds to the next step, the dry-keeping process in S7.

[0092] When the drying step S6 is completed, the temperature of the tableware 10, which was rinsed at a high temperature of 80°C (the water temperature Te2 disclosed in the present invention) in the final rinse, may not have dropped completely, and if the tableware 10 is left as is, condensation may form on the tableware 10. Therefore, the dry-keeping step S7 is a step in which a blower fan (not shown) for blowing air into the washing tank 2 is turned on (operated) to blow air onto the tableware 10 and prevent condensation from forming on the tableware 10.

[0093] Since the purpose of the dry-keeping step is to blow air onto the tableware 10, the drying heater (not shown) for heating the drying air is not turned on (operated). After the control unit 15 turns on (operates) the blower fan for a predetermined time, the control unit 15 turns off (stops) the blower fan, ending the dry-keeping step of step S7. The steps up to this point mark the completion of all processes from washing to drying. Note that the dry-keeping step of step S7 may not be necessary, and therefore the dry-keeping step of step S7 may not be included in the entire process from washing to drying.

[0094] If the control unit 15 determines in step S5 that the number of times the cleaning operation has been performed exceeds the predetermined number N, the control unit 15 executes a cleaning process for the water level detection device 7, more specifically, a cleaning process for the inside of the water level detection device 7 through which water passes, and the float 73, as a preventive measure to prevent small food particles and oil from accumulating inside the water level detection device 7.

[0095] The number of times the washing operation is performed may be the number of times all steps from the washing step S1 to the dry-keep step S7 are performed, or the number of steps from the washing step S1 to the final rinse step S4 are performed, and is set as appropriate. The predetermined number of times N may be 10 or 15, or may be a smaller or larger number, and is set as appropriate. Here, as an example for the purpose of explanation, N is set to 10.

[0096] If the control unit 15 determines in step S5 that the number of times the cleaning operation has been performed exceeds the predetermined number of 10 times, then in step S21 the control unit 15 opens the water supply valve 11 to supply water to the cleaning tank 2. When the water level detection device 7 detects that the required amount of water has accumulated inside the cleaning tank 2 up to the predetermined amount, the control unit 15 closes the water supply valve 11 to end the water supply.

[0097] In step S22 of heating the wash water shown in Figure 4, the water in the wash tank 2 is heated by the heater 3. In order to remove and wash away food debris and oil adhering to the inside of the water level detection device 7, float 73, etc., the water temperature is raised to Te3 in the washing process of the water level detection device 7. Te3 can be set within the range of Te1, which is the water temperature during washing (60°C), but less than 100°C, which is a temperature below boiling, or Te2, which is the water temperature during the final rinse (80°C), which will be described later, but less than 100°C, which is a temperature below boiling, to make it easier to remove and wash away adhering food debris and oil.

[0098] In step S22 for heating wash water, the water temperature is raised to Te3, and when the water temperature detection device 14 detects the water temperature Te3, the process proceeds to the next step S23, where the drain pump 8 is turned ON (operated) to drain the water. Note that although the description here has been given of the water temperature detection device 14 detecting the water temperature Te3, that is, performing the drain operation when the water temperature reaches Te3, the drain operation may not be performed immediately even when the water temperature detection device 14 detects the water temperature Te3, but may be configured to maintain the state for a predetermined time Ti4, for example 5 minutes, after detecting the water temperature Te3 before performing the drain operation.

[0099] When the drain pump 8 is turned on (operated), water is drawn from the cleaning tank recess 2b to the drain pump 8 connected by a connecting pipe 8a, flows from the drain pump 8 into the inside of the water level detection device 7 connected by a connecting pipe 8b, passes through the space in which the float 73 is located, and is drained out of the cleaning tank 2 through the drain pipe section 77 and the drain pipe 9.

[0100] In step S5, a cleaning process for the water level detection device 7 is carried out as a preventive measure against the accumulation of small food particles and oil inside the water level detection device 7, specifically a cleaning process for the inside of the water level detection device 7 through which water passes, the float 73. After that, the next step is a drying process in S6 and a dry-keeping process in S7, and the entire process from cleaning to drying is completed.

[0101] As described above, by periodically performing a process of cleaning the water level detection device, the frequency of malfunctions in the water level detection device can be reduced, making it possible to create a dishwasher that users can use with confidence. [Explanation of symbols]

[0102] Te1: Water temperature during the washing process, Te2: Water temperature during the final rinse (heated rinse) process, Te3: Water temperature during the washing process of the water level detection device, Te4: Temperature during abnormality (empty burn), Ti1: Predetermined time, Ti2: Predetermined time, Ti3: Predetermined time, Ti4: Predetermined time, 1: Housing, 1a: Housing opening, 2: Washing tank, 2a: Washing tank opening, 2b: Washing tank recess, 3: Heater, 4: Residue filter, 5: Lid, 6: Door, 6a: Handle, 7: Water level detection device (water level detection means of the present disclosure), 8: Drain pump, 8a: Connecting pipe, 8b: Connecting pipe, 9: Drain pipe, 10: Dishes, 11: Water supply valve, 12: Washing pump, 13: Washing nozzle, 13a: Shaft, 14: Water temperature detection device, 15: Control unit, 16: Water supply hose, 17: Dish basket, 71: Water level detection device case, 72 Water level detection device cover, 73 float, 73a float guide hole, 74 detector, 75 detector holding tube, 76 water supply pipe section, 77 drain pipe section, 78 magnet, 100 dishwasher.

Claims

1. The housing and a cleaning tank disposed inside the housing and configured to accommodate objects to be cleaned therein in a removable manner; a water supply means for supplying water from the outside into the cleaning tank; a water level detection means for detecting the level of water supplied from the outside via the water supply means and used in the washing process and rinsing process of the object to be washed; a cleaning means for cleaning and rinsing the object to be cleaned in a cleaning operation including the cleaning step and the rinsing step of the object to be cleaned using the water supplied into the cleaning tank; a drainage means for draining the water supplied into the cleaning tank from the cleaning tank; a control means for controlling the cleaning operation of the cleaning means and the operation of the drainage means, The control means counts the number of times the washing operation is performed, and when the number of times the washing operation is performed exceeds a predetermined number N, the dishwasher performs the washing process of the water level detection means.

2. The washing machine further comprises a heating means provided in the washing tank for heating the water supplied to the washing tank used in the washing operation including the washing step and the rinsing step of the object to be washed, and a temperature detection element for detecting the temperature of the water; the cleaning step of the water level detection means is performed by draining water using the drainage means, 2. The dishwasher of claim 1, wherein, during the washing process of the water level detection means, when the water level detection means detects a predetermined water level for the water supplied from outside into the washing tank, and the temperature detection element detects that the temperature of the water has reached a predetermined temperature, the control means operates the drainage means to drain the water.

3. The washing machine further comprises a heating means provided in the washing tank for heating the water supplied to the washing tank used in the washing operation including the washing step and the rinsing step of the object to be washed, and a temperature detection element for detecting the temperature of the water; the cleaning step of the water level detection means is performed by draining water using the drainage means, 2. The dishwasher of claim 1, wherein, during the cleaning operation of the water level detection means, after the water level detection means detects a predetermined water level for the water supplied from outside into the cleaning tank, and the temperature detection element detects that the temperature of the water has reached a predetermined temperature, the control means measures that a predetermined time Ti3 has elapsed, and then the control means operates the drainage means to drain the water.

4. 4. The dishwasher of claim 1, wherein the rinsing step is a step of performing multiple rinses, and at least one of the multiple rinses is a heated rinse in which the water used for rinsing is heated by the heating means, and the temperature Te2 of the water during the heated rinse detected by the temperature detection element is higher than the temperature Te1 of the water during the washing step, and the temperature Te3 of the water during the washing step detected by the water level detection means is equal to or higher than the temperature Te1 of the water during the washing step and less than 100°C.

5. 4. The dishwasher of claim 1, wherein the rinsing step is a step of performing multiple rinses, and at least one of the multiple rinses is a heated rinse in which the water used for rinsing is heated by the heating means, and the temperature Te2 of the water during the heated rinse detected by the temperature detection element is higher than the temperature Te1 of the water during the washing step, and the temperature Te3 of the water during the washing step detected by the water level detection means is higher than the temperature Te2 of the water during the washing step and less than 100°C.

6. The time required for the water level detection means to reach a predetermined water level is set to a predetermined time Ti1. The dishwasher described in claim 4, wherein the control means measures the elapsed time Ti2 from when the water supply means starts supplying water into the washing tank until the water level detection means detects a preset water level, and when the elapsed time Ti2 until the preset water level is detected exceeds the preset time Ti1, the control means stops the water supply by the water supply means and operates the drainage means to drain the water to perform the washing process of the water level detection means.

7. The time required for the water level detection means to reach a predetermined water level is set to a predetermined time Ti1. The dishwasher described in claim 4, wherein the control means measures the elapsed time Ti2 from when the water supply means starts supplying water into the washing tank until the water level detection means detects a preset water level, and when the temperature detection element detects that the elapsed time Ti2 until the detection of the preset water level has exceeded a temperature Te4 at which the control means determines an abnormality before it exceeds the preset time Ti1, the control means stops supplying power to the heating means, stops water supply by the water supply means, and alerts the user of the abnormality.

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