Dishwasher

Abstract

To suppress erroneous detection caused by conduction between both bubble detection electrodes by washing water droplets when both bubble detection electrodes are provided in a flow duct 4 for introducing air from a fan 5 to an air inlet 27 opened in a lower part of a washing chamber 2 in a dishwasher which includes a pair of first and second bubble detection electrodes 61, 62 and can detect bubbles by conduction between both bubble detection electrodes through the bubbles when the bubbles generated by a detergent included in washing water make contact with both bubble detection electrodes.SOLUTION: A first bubble detection electrode 61 is provided in a manner that an electrode part 61 is positioned inside a side wall 41 of a flow duct 4. A second bubble detection electrode 62 is provided in a manner that the electrode part 61 follows the side wall in the outside of the side wall 41 of the flow duct 4. A through-hole 42 is opened at a part facing the electrode part 61 of the second bubble detection electrode 62 in the side wall 41.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a dishwasher including a washing tub for storing an object to be washed, a washing nozzle provided in the washing tub, and a washing pump for supplying washing water in the washing tub to the washing nozzle.

Background Art

[0002] In this type of dishwasher, when an easily foaming detergent is used, a large amount of generated foam acts as a cushion on the surface of the object to be washed. Even if the washing water is vigorously jetted from the washing nozzle, the momentum of the washing water hitting the object to be washed is weakened, making it difficult to remove dirt, or a large amount of foam is sucked into the washing pump, resulting in a decrease in the discharge pressure of the washing water from the washing pump.

[0003] Therefore, conventionally, as disclosed in Patent Document 1, a pair of first and second foam detection electrodes are provided in a water level detection tank communicating with the bottom of the washing tub. Each foam detection electrode has a rod-shaped electrode portion and a terminal portion at the base end of the electrode portion. The electrode portions of the first and second foam detection electrodes protrude into the tank. When a large amount of foam is generated in the washing tub, the foam enters the tank and rises upward. When the foam contacts the electrode portions of both foam detection electrodes, the electrode portions of both foam detection electrodes are electrically connected through the foam, and the generation of foam is detected. However, in this case, since the tank is likely to be filled with water vapor, the electrode portions of the foam detection electrodes protruding into the tank are likely to corrode. To ensure durability, it is necessary to form the electrode portions of the foam detection electrodes from a highly corrosion-resistant material such as SUS304, which increases the cost.

[0004] Here, the dishwasher is equipped with a blower fan located outside the washing tank, above the air intake, and connected via a blower duct to an air intake opening in the lower part of the side wall or bottom wall of the washing tank. The applicant of this application has focused on this blower duct and, in order to resolve the above-mentioned problems, has previously proposed in Japanese Patent Application No. 2021-140949 a system in which both first and second bubble detection electrodes are provided in the blower duct, positioned above the air intake, with the electrode portions of both bubble detection electrodes protruding into the blower duct.

[0005] In this system, after the cleaning process, in which cleaning water is sprayed from the cleaning nozzle to clean the object to be cleaned, or the rinsing process, in which water is sprayed as cleaning water from the cleaning nozzle to rinse the object to be cleaned, the blower fan is driven to return the water vapor in the blower duct to the cleaning tank. As a result, water vapor does not remain around the electrode parts of both bubble detection electrodes in the blower duct for a long time, and the electrode parts are less likely to corrode. Consequently, corrosion resistance can be ensured without forming the electrode parts of both bubble detection electrodes from highly corrosion-resistant materials, thereby reducing costs.

[0006] However, the following problems were discovered. Specifically, during the washing and rinsing processes, splashes of washing water entering the air duct adhere to the electrode portion of the foam detection electrode, causing calcium carbonate and other substances to precipitate on the electrode surface over time, which increases the hydrophilicity of the electrode surface. As a result, electrical conductivity may occur between the electrode portions of both foam detection electrodes due to splashes of washing water, potentially leading to false detections. To resolve this problem, it is conceivable to increase the distance between the electrode portions of both foam detection electrodes, but this would increase the size of the air duct. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2004-321466 [Overview of the project] [Problems that the invention aims to solve]

[0008] In view of the above points, the present invention aims to provide a dishwasher that suppresses false detections and does not require an enlarged air duct. [Means for solving the problem]

[0009] To solve the above problems, the present invention provides a dishwasher comprising a washing tank for storing items to be washed, a washing nozzle provided in the washing tank, a washing pump for supplying washing water from the washing tank to the washing nozzle, and a pair of first and second foam detection electrodes, each foam detection electrode having a rod-shaped electrode portion and a terminal portion at the base end of the electrode portion, wherein foam generated due to detergent contained in the washing water comes into contact with the electrode portions of both the first and second foam detection electrodes, and foam can be detected by electrical conduction between the electrode portions of both foam detection electrodes via the foam, wherein a supply is provided in the lower part of the side wall or bottom wall of the washing tank The cleaning tank is equipped with a blower fan that is connected to the air inlet via a blower duct and positioned above the air intake port outside the cleaning tank, and both first and second bubble detection electrodes are provided on the blower duct, positioned above the air intake port, wherein the first bubble detection electrode is provided so that its electrode portion is located inside the side wall of the blower duct, and the second bubble detection electrode is provided so that its electrode portion is located outside the side wall of the blower duct and along the side wall, and a through-hole is provided in the side wall at a position opposite to the electrode portion of the second bubble detection electrode.

[0010] According to the present invention, when foam enters the air supply duct from the air intake and the upper surface level of the foam becomes higher than the height at which the electrode portions of both the first and second foam detection electrodes are positioned, the foam touches the electrode portion of the first foam detection electrode, and foam overflowing from the penetration port touches the electrode portion of the second foam detection electrode. Conduction occurs between the electrode portions of both foam detection electrodes via the foam, and the foam is detected. Furthermore, since the electrode portion of the second foam detection electrode is positioned on the outside of the side wall of the air supply duct, it is less likely for cleaning water droplets to adhere to this electrode portion. Therefore, conduction between the electrode portions of both foam detection electrodes due to cleaning water droplets is suppressed, and false detection can be effectively prevented. In addition, by positioning the electrode portion of the first foam detection electrode inside the air supply duct and the electrode portion of the second foam detection electrode outside the air supply duct, a sufficient distance can be secured between the electrode portions of both foam detection electrodes, thus eliminating the need to enlarge the air supply duct.

[0011] Furthermore, in the present invention, it is desirable to position one of the electrode portions of the first bubble detection electrode and the second bubble detection electrode with a vertical and horizontal offset relative to the other electrode portion. This effectively suppresses electrical conductivity between the electrode portions of both bubble detection electrodes due to splashes of washing water.

[0012] Furthermore, in the present invention, it is desirable to provide a cylindrical portion projecting from the inner surface of the side wall of the air supply duct, so as to surround the electrode portion of the first bubble detection electrode, with a length less than or equal to the protrusion length of the electrode portion of the first bubble detection electrode from the inner surface. This makes it less likely for cleaning water droplets to adhere to parts of the electrode portion of the first bubble detection electrode other than the tip, and more effectively suppresses electrical conductivity between the electrode portions of both bubble detection electrodes due to cleaning water droplets. When the upper surface level of the bubbles that have entered the air supply duct reaches the height at which the electrode portion of the first bubble detection electrode is positioned, the bubbles will reliably come into contact with the tip of the electrode portion. Therefore, the bubble detection performance will not be reduced.

[0013] Furthermore, in the present invention, it is desirable to provide a foam receiving section on the outer surface of the side wall of the air supply duct to receive foam overflowing from the penetration port, thereby making it easier for the foam to come into contact with the electrode portion of the second foam detection electrode. This increases the certainty that foam overflowing from the penetration port will come into contact with the electrode portion of the second foam detection electrode, thereby improving the foam detection performance.

[0014] Furthermore, in the present invention, it is desirable to provide a splash guard portion on the inner surface of the side wall of the air supply duct, adjacent to the penetration opening, to suppress the scattering of cleaning water splashes from the inside of the air supply duct to the penetration opening. This improves the effect of suppressing the adhesion of cleaning water splashes to the electrode portion of the second bubble detection electrode, and effectively suppresses electrical conductivity between the electrode portions of both bubble detection electrodes due to cleaning water splashes.

[0015] Furthermore, in this invention, an overflow port is provided on the side wall of the air supply duct, positioned below the electrode portions of both the first and second bubble detection electrodes, so that the cleaning water overflows when the water level of the cleaning water in the cleaning tank exceeds a predetermined level. A guide plate is provided inside the air supply duct to guide the air blown from the air supply fan so that it flows around the installation portions of both the first and second bubble detection electrodes and the overflow port, and it is desirable that the lower end of the guide plate extends below the upper edge of the air intake port. By providing the overflow port as described above, even if the water supply to the cleaning tank is not properly stopped and cleaning water enters the air supply duct from the air intake port, the cleaning water will overflow from the overflow port and will not come into contact with the electrode portions of both bubble detection electrodes, thereby preventing false detections. In addition, by providing the guide plate as described above, it is possible to suppress the air blown from the air supply fan from escaping from the overflow port. Furthermore, by extending the lower end of the guide plate below the upper edge of the air intake, as described later, it becomes more difficult for cleaning water droplets to scatter onto the installation area of ​​both the first and second bubble detection electrodes, and electrical conductivity between the electrode portions of both bubble detection electrodes due to cleaning water droplets can be effectively suppressed. [Brief explanation of the drawing]

[0016] [Figure 1] A cross-sectional side view of a dishwasher according to an embodiment of the present invention. [Figure 2] A perspective view of the main part of the air duct provided in the dishwasher of the embodiment, as seen from the outside. [Figure 3] A perspective view of the main part of the air duct installed in the dishwasher of the embodiment, as seen from the inside. [Modes for carrying out the invention]

[0017] The dishwasher according to the embodiment of the present invention shown in Figure 1 is a built-in type that is installed in a system kitchen and has a washing tank 2 that can be freely pulled out from the front inside a main body 1 with an open front. Water is supplied to the washing tank 2 from a water supply valve (not shown) located inside the main body 1 via a water supply hose. A front cover 21 is attached to the front of the washing tank 2 to close the front of the main body 1. In addition, a seal cover 11 is provided at the top inside the main body 1 to close the open top surface of the washing tank 2.

[0018] The washing tank 2 houses a lower basket 22 and an upper basket 23 that support the items to be washed, such as dishes, and is equipped with washing nozzles 24 that spray washing water towards these baskets 22 and 23. The washing nozzles 24 have a lower nozzle 241 that extends horizontally at the bottom of the washing tank 2 and is rotatable around a vertical axis at the center of its longitudinal direction, and an upward-extending center nozzle 242 that is erected at the center of the longitudinal direction of the lower nozzle 241. A nozzle guard frame 221 is erected in the center of the lower basket 22 to prevent the items to be washed W placed in it from interfering with the center nozzle 242.

[0019] A cleaning pump 3 is installed on the underside of the bottom wall of the cleaning tank 2, communicating with a cleaning water reservoir 25 recessed in the bottom wall. When the cleaning pump 3 is rotated forward, cleaning water in the cleaning tank 2 is supplied to the cleaning nozzle 24 via the reservoir 25 and the cleaning pump 3, and when the cleaning pump 3 is rotated in reverse, the cleaning water is drained from the cleaning tank 2. A heater 26 is also provided at the bottom of the cleaning tank 2 so as to sink below the water surface when water is supplied to the cleaning tank 2.

[0020] The dishwasher is further equipped with a drying fan 5 located outside the washing tank 2, above the air intake 27, and connected via an air duct 4 to an air intake 27 opened at the lower part of the rear side wall of the washing tank 2. The air duct 4 is longitudinal in the vertical direction and has an open front. By attaching this air duct 4 to the rear surface of the rear side wall of the washing tank 2 such that the front of the air duct 4 is closed by the rear side wall, an air passage 4a communicating with the air intake 27 is defined between the air duct 4 and the rear side wall. The drying fan 5 is attached to the rear surface of the rear side wall of the washing tank 2, with the air duct 4 connected to the upper end of the drying fan 5.

[0021] When the operation switch of the dishwashing machine is turned on, first, water is supplied to the washing tub 2, and detergent is mixed into this water from a detergent supply means (not shown) to generate washing water. Then, when the water level in the washing tub 2 reaches a predetermined level, the water supply is stopped. After that, while heating the washing water with the heater 26, the washing pump 3 is rotated forward to inject the washing water from the washing nozzle 24, and a washing process for washing the object to be washed W stored in the washing tub 2 is performed for a predetermined time. After the completion of the washing process, the washing pump 3 is rotated reversely to drain the washing water in the washing tub 2. Next, after supplying water to the washing tub 2, the washing pump 3 is rotated forward to inject water as washing water from the washing nozzle 24, and a rinsing process for rinsing the object to be washed W is performed for a predetermined time. After the completion of the rinsing process, the washing pump 3 is rotated reversely to drain the water in the washing tub 2. Then, while heating the air in the washing tub 2 with the heater 26, the drying fan 5 is driven to blow air into the washing tub 2, and a drying process for drying the object to be washed W with the blown air is performed for a predetermined time.

[0022] Here, when a detergent that easily foams is used, a large amount of foam is generated in the washing tub 2 during the washing process. Therefore, as also shown in FIGS. 2 and 3, a pair of first and second foam detection electrodes 61 and 62 are provided in the air supply duct 4 at a position above the air supply port 27. Here, each foam detection electrode 61, 62 has a rod-shaped electrode portion 61 and a terminal portion 62 at the base end of the electrode portion 61. The first foam detection electrode 61 is provided such that its electrode portion 61 is located inside the rear side wall 41 of the air supply duct 4, specifically, so as to protrude inward, that is, forward from the side wall 41. On the other hand, the second foam detection electrode 62 is provided such that its electrode portion 61 is along the outer side of the side wall 41 of the air supply duct 4 and extends in the lateral direction along the side wall 41.

[0023] Further, a through hole 42 is formed in a portion of the side wall 41 of the air duct 4 that faces the electrode portion 61 of the second foam detection electrode 62. The installation portions of the first and second foam detection electrodes 61 and 62 on the side wall 41 are composed of a removable partition wall 41a, and the through hole 42 is formed in this partition wall 41a. The terminal portions 62 of the first and second foam detection electrodes 61 and 62 are installed in a terminal cover 63 outside the side wall 41. Further, ribs 43 are protruding from the outer surface of the side wall 41 so as to surround the installation portions of the first and second foam detection electrodes 61 and 62 from above and inward in the lateral direction. When the cleaning tank 2 is taken in and out, the rib 43 can prevent a water supply hose (not shown) connected to the cleaning tank 2 from touching the installation portions of the two foam detection electrodes 61 and 62.

[0024] When a large amount of foam is generated in the cleaning tank 2, the foam enters the air duct 4 through the air supply port 27. When the upper surface level of the foam in the air duct 4 becomes higher than the arrangement heights of the electrode portions 61 and 61 of the first and second foam detection electrodes 61 and 62, the foam touches the electrode portion 61 of the first foam detection electrode 61, and the foam overflowing from the through hole 42 touches the electrode portion 61 of the second foam detection electrode 62, and the electrode portions 61 and 61 of the two foam detection electrodes 61 and 62 are electrically connected through the foam, and the foam is detected. When the generation of foam is detected, the cleaning process is interrupted, an abnormality notification is performed by a notification means (not shown), and further, an anti-foaming process for discharging the generated foam is executed.

[0025] Here, in the drying process after the rinsing process, by driving the drying fan 5, the water vapor in the air duct 4 can be returned to the cleaning tank 2. Therefore, water vapor does not stay around the electrode portion 61 of the first foam detection electrode 61 in the air duct 4 for a long time, and water vapor does not stay around the electrode portion 61 of the second foam detection electrode 62 outside the air duct 4 for a long time, and the electrode portions 61 and 61 of the two foam detection electrodes 61 and 62 are less likely to corrode. Therefore, corrosion resistance can be ensured without forming the electrode portions 61 and 61 of the two foam detection electrodes with a material having high corrosion resistance, and cost reduction can be achieved.

[0026] Furthermore, since the electrode portion 61 of the second bubble detection electrode 62 is positioned on the outside of the side wall 41 of the air supply duct 4, it is less likely for cleaning water droplets to adhere to the electrode portion 61. Therefore, electrical conductivity between the electrode portions 61, 61 of both the first and second bubble detection electrodes 61, 62 due to cleaning water droplets can be suppressed, effectively preventing false detections. Moreover, by positioning the electrode portion 61 of the first bubble detection electrode 61 inside the air supply duct 4 and the electrode portion 61 of the second bubble detection electrode 62 outside the air supply duct 4, a sufficient distance can be secured between the electrode portions 61, 61 of both bubble detection electrodes 61, 62, thus avoiding the need to enlarge the air supply duct 4.

[0027] Furthermore, in this embodiment, one of the electrode portions 61 of the first bubble detection electrode 61 and the electrode portion 61 of the second bubble detection electrode 62 is positioned vertically and horizontally relative to the other. Specifically, the electrode portion 61 of the second bubble detection electrode 62 is positioned above and laterally outward relative to the electrode portion 61 of the first bubble detection electrode 61. This effectively suppresses electrical conductivity between the electrode portions 61, 61 of both the first and second bubble detection electrodes 61, 62 due to washing water splashes.

[0028] Furthermore, in this embodiment, a cylindrical portion 44 is provided protruding from the inner surface of the rear side wall 41 of the air supply duct 4, surrounding the electrode portion 61 of the first bubble detection electrode 61, with a length less than or equal to the protrusion length of the electrode portion 61 of the first bubble detection electrode 61 from the inner surface. This makes it difficult for cleaning water droplets to adhere to parts of the electrode portion 61 of the first bubble detection electrode 61 other than the tip. Therefore, electrical conductivity between the electrode portions 61, 61 of both the first and second bubble detection electrodes 61, 62 due to cleaning water droplets can be suppressed more effectively. When the upper surface level of bubbles that have entered the air supply duct 4 reaches the height at which the electrode portion 61 of the first bubble detection electrode 61 is positioned, the bubbles will reliably come into contact with the tip of the electrode portion 61. Therefore, the bubble detection performance will not be reduced.

[0029] Furthermore, in this embodiment, a foam receiving section 45 is provided on the outer surface of the side wall 41 of the air supply duct 4, more precisely on the outer surface of the separation wall 41a, to receive foam overflowing from the through-hole 42 and to make it easier for this foam to come into contact with the electrode portion 61 of the second foam detection electrode 62. This increases the certainty that foam overflowing from the through-hole 42 will come into contact with the electrode portion 61 of the second foam detection electrode 62, thereby improving the foam detection performance.

[0030] In this embodiment, the foam receiving section 45 is formed in a cylindrical shape slightly larger than the through-hole 42 that surrounds the through-hole 42 and the electrode section 61. However, it is also possible to form it in a cylindrical shape the same size as the through-hole 42, a U-shape with the top open, or even a flat plate shape along the lower edge of the through-hole 42.

[0031] Furthermore, in this embodiment, a splash guard portion 46 is provided on the inner surface of the side wall 41 of the air supply duct 4, adjacent to the through-hole 42, to suppress the scattering of cleaning water splashes from the inside of the air supply duct 4 to the through-hole 42. This improves the effect of suppressing the adhesion of cleaning water splashes to the electrode portion 61 of the second bubble detection electrode 62, and effectively suppresses the conduction of the electrode portions 61, 61 of both the first and second bubble detection electrodes 61, 62 due to cleaning water splashes.

[0032] In this embodiment, the splash guard portion 46 is formed in an L-shape along the lower edge and the lateral inner edge of the through-hole 42. However, it can also be formed in a cylindrical shape surrounding the through-hole 42, a U-shape with the top open, or even a flat plate shape along only the lower edge of the through-hole 42.

[0033] Furthermore, in this embodiment, an overflow port 47 is provided on the side wall 41 of the air supply duct 4, positioned below the electrode portions 61, 61 of both the first and second bubble detection electrodes 61, 62, so that when the water level of the cleaning water in the cleaning tank 2 exceeds a predetermined level above the predetermined level at which the water supply is stopped, the cleaning water overflows. As a result, even if the water supply to the cleaning tank 2 is not properly stopped and cleaning water enters the air supply duct 4 from the air intake port 27, the cleaning water will overflow from the overflow port 47 and will not come into contact with the electrode portions 61, thus preventing false detection.

[0034] Furthermore, a guide plate section 48 is provided inside the air supply duct 4 to guide the air supplied from the drying fan 5 so that it flows around the installation areas of the first and second bubble detection electrodes 61 and 62 and the overflow port 47. Specifically, the guide plate section 48 is provided protruding from the inner surface of the side wall 41 of the air supply duct 4, extending diagonally downward from a point above the installation area of ​​the second bubble detection electrode 62 at the lateral outward end of the air supply duct 4, toward a point a certain distance laterally inward from the first bubble detection electrode 61, and then extending downward through a point laterally inward from the overflow port 47. By providing the guide plate section 48 in this manner, it is possible to prevent the air supplied from the drying fan 5 from escaping through the overflow port 47.

[0035] Furthermore, the lower end of the guide plate section 48 extends below the upper edge of the air intake port 27. This makes it difficult for splashes of cleaning water entering from the air intake port 27 to scatter onto the installation areas of the first and second bubble detection electrodes 61 and 62, and into the air duct 4 located on the opposite side of the overflow port 47 and the guide plate section 48. As a result, electrical conductivity between the electrode portions of the two bubble detection electrodes due to splashes of cleaning water can be effectively suppressed.

[0036] Although embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, it is also possible to provide a separate blower fan for dehumidifying the foam detection electrodes 61 and 62, separate from the drying fan 5, and a separate blower duct from the blower duct 4 that guides the air from this blower fan into the washing tank 2, and to provide the foam detection electrodes 61 and 62 in this blower duct. However, as in the above embodiment, if the foam detection electrodes 61 and 62 are provided in the blower duct 4 that guides the air from the drying fan 5 into the washing tank 2, there is no need to provide a separate blower fan or blower duct for dehumidifying the foam detection electrodes 61 and 62, which is advantageous in terms of cost reduction. Furthermore, since the foam detection electrodes 61 and 62 are dehumidified in the drying process for drying the objects to be washed, a separate process for dehumidifying the foam detection electrodes 61 and 62 is also unnecessary, making it more efficient.

[0037] Furthermore, although the above embodiment provides an air intake 27 at the lower part of the rear side wall of the washing tank 2, it is also possible to provide the air intake 27 at the bottom wall of the washing tank 2. Moreover, although the dishwasher in the above embodiment is a built-in type, the present invention can also be similarly applied to a tabletop dishwasher that has an open front surface for the washing tank and a front door that opens and closes this front surface. [Explanation of Symbols]

[0038] 2...Washing tank, 24...Washing nozzle, 27...Air inlet, 3...Washing pump, 4...Air duct, 41...Side wall, 42...Penetration port, 44...Cylindrical section, 45...Foam receiving section, 46...Splash guard section, 47...Overflow port, 48...Guidance panel section, 5...Drying fan (air blower fan), 61...First foam detection electrode, 62...Second foam detection electrode, 61...Electrode section, 62...Terminal section.

Claims

1. A dishwasher comprising a washing tank for storing items to be washed, a washing nozzle provided in the washing tank, a washing pump for supplying washing water from the washing tank to the washing nozzle, and a pair of first and second foam detection electrodes, each foam detection electrode having a rod-shaped electrode portion and a terminal portion at the base end of the electrode portion, wherein foam generated due to detergent contained in the washing water comes into contact with the electrode portions of both the first and second foam detection electrodes, and foam can be detected by electrical conduction between the electrode portions of both foam detection electrodes via the foam, A blower fan is provided outside the washing tank, positioned above the air intake, and connected via a blower duct to an air intake opening in the lower part of the side wall or bottom wall of the washing tank, and both first and second bubble detection electrodes are provided on the blower duct, positioned above the air intake. A dishwasher characterized in that the first bubble detection electrode is provided such that its electrode portion is located inside the side wall of the air supply duct, and the second bubble detection electrode is provided such that its electrode portion is located outside the side wall of the air supply duct and along the side wall, and a through-hole is provided in the side wall at a position opposite to the electrode portion of the second bubble detection electrode.

2. The dishwasher according to claim 1, characterized in that one of the electrode portions of the first bubble detection electrode and the second bubble detection electrode is positioned offset vertically and horizontally from the other electrode portion.

3. The dishwasher according to claim 1, characterized in that a cylindrical portion is provided protruding from the inner surface of the side wall of the air supply duct, surrounding the periphery of the electrode portion of the first bubble detection electrode, and having a length less than or equal to the protrusion length of the electrode portion of the first bubble detection electrode from the inner surface.

4. The dishwasher according to claim 1, characterized in that a foam receiving portion is provided on the outer surface of the side wall of the air supply duct for receiving foam overflowing from the through-hole, and for making it easier for the foam to come into contact with the electrode portion of the second foam detection electrode.

5. The dishwasher according to claim 1, characterized in that a splash guard portion is provided on the inner surface of the side wall of the air duct, adjacent to the through-hole, to suppress the scattering of washing water splashes from the inside of the air duct to the through-hole.

6. The dishwasher according to claim 1, characterized in that an overflow port is provided in the side wall of the air supply duct, positioned below the electrode portions of the first and second bubble detection electrodes, from which washing water overflows when the water level of the washing water in the washing tank exceeds a predetermined level, and a guide plate is provided in the air supply duct to guide the air blown from the air supply fan to flow around the installation portions of the first and second bubble detection electrodes and the overflow port, and the lower end of the guide plate extends below the upper edge of the air intake port.

Images