Filter device and washing machine

Abstract

To provide a filtration device and a washing machine including the filtration device which can provide improved maintainability through preventing clogging of a filter.SOLUTION: A filtration device 20 includes a case 21, a filter 23 placed in the case 21, a rotator 32 placed in the filter 23, and raking members 33 which are held by the rotator 32 in the filter 23. The filter 23 takes water flowing into the case 21 into the filter 23 itself through an inlet opening 25F and captures foreign objects contained in the water at its inner periphery 23A. The rotator 32 rotates due to momentum of water taken, through the inlet opening 25F, into the filter 23. A raking member 33 can slide between an advancing position in which it comes near to the inner periphery 23A and a withdrawing position in which it goes away from the inner periphery 23A, and it is biased towards the withdrawing position by a biasing member 49.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a filter device and a washing machine including a filter device. [Background technology]

[0002] The washing machine described in the following Patent Document 1 includes a housing, a washing tub arranged in the housing, a drainage channel that drains water in the washing tub out of the housing, and a drainage filter that is detachably attached to the drainage channel. The drainage filter includes a comb portion having a plurality of pins. When wastewater flowing through the drainage channel passes around the pins in the drainage filter, foreign matter contained in the wastewater becomes entangled with the pins and is captured. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-103718 A Summary of the Invention [Problem to be solved by the invention]

[0004] The drainage filter described in Patent Document 1 is designed to capture long foreign objects such as lint and hair, and therefore the gaps between adjacent pins in the comb section, i.e., the filter holes, are relatively large, making the drainage filter less likely to become clogged. Meanwhile, there has been a recent demand for measures to prevent resinous foreign objects with a size of several tens of μm, known as microplastics, from being released into the natural world. In order to meet such demands, the filter holes can be made smaller, but as the filter holes become smaller, the drainage filter becomes more likely to become clogged, and users must frequently maintain the drainage filter, which is troublesome.

[0005] The present invention has been made against this background, and aims to provide a filter device that can suppress clogging of the filter and improve maintainability, and a washing machine including this filter device. [Means for solving the problem]

[0006] The present invention relates to a case having an inlet and an outlet, which allows water in a drainage channel of a washing machine to flow into the case from the inlet and allows water in the case to flow out from the outlet, and a filter disposed in the case, which has a cylindrical inner circumferential surface portion having a vertically extending central axis and a plurality of filter holes distributed on the inner circumferential surface portion, and has an intake port for taking in water flowing into the case from the inlet into the filter, and which detects foreign matters contained in water that is taken into the filter from the intake port and then flows out of the filter from the filter holes. The filter device includes: a filter that captures objects on the inner surface; a rotor that is disposed within the filter and rotates about the central axis due to the force of water taken into the filter from the inlet; a scraping member that is supported by the rotor within the filter and scrapes off foreign objects from the inner surface, the scraping member being slidable in a radial direction based on the central axis between an advanced position approaching the inner surface and a retracted position moving away from the inner surface toward the central axis; and a biasing member that biases the scraping member toward the retracted position.

[0007] The present invention is also characterized in that the rotating body includes a blade that receives water taken into the filter from the inlet, the blade being positioned above the lower half of the internal space of the filter, and the inlet faces the blade from a circumferential direction around the central axis or a tangential direction to the circumferential direction.

[0008] In the present invention, the filter device includes a weight connected to the scraping member.

[0009] The present invention is also characterized in that the filter has an overflow hole in the area above the filter hole, which allows water in the filter to overflow outside the filter, and the case has a recess that is recessed away from the overflow hole, and the outflow outlet is positioned directly below the overflow hole.

[0010] The present invention also relates to a washing machine including a washing tub that stores laundry, an upstream flow path connected to the washing tub, and a drainage passage having a first downstream flow path and a second downstream flow path branched off from the upstream flow path, a drainage valve that opens and closes the first downstream flow path, a pump provided in the second downstream flow path that drains water in the upstream flow path to the second downstream flow path, and the filter device provided in a downstream region of the second downstream flow path that is farther from the upstream flow path than the pump. Effect of the Invention

[0011] According to the present invention, in the filter device, the water flowing through the drainage channel of the washing machine flows into the case from the inlet, is taken into the filter from the inlet, and then flows out of the filter through the filter hole on the inner peripheral surface of the filter and is discharged from the washing machine through the outlet of the case. When the water flows out of the filter from the filter hole, foreign matter contained in the water is captured on the inner peripheral surface of the filter. When the rotor arranged in the filter rotates due to the momentum of the water taken into the filter from the inlet, the scraping member supported by the rotor advances from the retreated position to the advanced position against the biasing force of the biasing member due to the centrifugal force and contacts the foreign matter on the inner peripheral surface of the filter. Then, the rotation speed of the rotor temporarily decreases, so that the centrifugal force is reduced, and the scraping member retreats to the retreated position due to the biasing force of the biasing member. Then, when the rotation speed of the rotor recovers and the centrifugal force increases, the scraping member advances again to the advanced position and contacts the foreign matter on the inner peripheral surface of the filter. In this way, the scraping member repeatedly moves between the advanced position and the retracted position while the rotor rotates to drain water, thereby repeatedly contacting the foreign matter on the inner peripheral surface of the filter, thereby efficiently scraping the foreign matter off the inner peripheral surface of the filter. This makes it possible to prevent the filter from clogging the filter holes and improve maintainability.

[0012] According to the present invention, the blades included in the rotor receive water taken into the filter from the inlet, causing the rotor to rotate. The blades are disposed above the lower half of the internal space of the filter where water is likely to accumulate. Furthermore, the inlet faces the blades from the central axis of the inner peripheral surface of the filter, that is, the circumferential direction around the rotation axis of the rotor, or the tangential direction to this circumferential direction. As a result, the blades are less likely to receive resistance from the water that accumulates in the lower half of the internal space of the filter, while efficiently receiving the water taken into the filter from the inlet, allowing the rotor to rotate vigorously. Therefore, a large centrifugal force is generated, which makes it easier for the scraping member to advance to the advance position, so that the scraping member can more efficiently scrape off foreign matter from the inner peripheral surface of the filter. This further suppresses clogging of the filter in the filter holes, thereby further improving maintainability.

[0013] Furthermore, according to the present invention, the weight connected to the scraping member generates a large centrifugal force, which makes it easier for the scraping member to advance to the advanced position, so that the scraping member can more efficiently scrape off foreign matter from the inner peripheral surface of the filter. This further reduces clogging of the filter holes and further improves maintainability.

[0014] In addition, according to the present invention, even if the filter becomes clogged, the water in the filter overflows from the overflow hole and flows out of the case from the outlet, so that the water flowing in the drainage channel of the washing machine can be smoothly discharged outside the machine. Furthermore, a recess is provided in the case away from the overflow hole, and the outlet is located directly below the overflow hole, so that the water that overflows from the overflow hole to the outside of the filter can be quickly transferred from the recess to the outlet and discharged outside the machine.

[0015] According to the present invention, the drainage path of the washing machine is branched into a first downstream path and a second downstream path at a downstream portion of the upstream path connected to the washing tub. A pump and a filter device are provided in the second downstream path. When the pump operates with the drain valve closing the first downstream path, the water in the upstream path flows through the second downstream path, foreign objects are captured by the filter device, and the water is discharged outside the machine. When the amount of water in the washing tub decreases and the pump is more likely to entrap air, the pump can be stopped and the first downstream path can be opened by the drain valve. The remaining water then flows from the upstream path through the first downstream path and is discharged outside the machine, thereby suppressing noise caused by the pump operating with air entrapped, and discharging all water from the washing tub outside the machine. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic vertical sectional right side view of a washing machine according to one embodiment of the present invention; [Diagram 2] FIG. 2 is a perspective view of a filter device included in a washing machine. [Diagram 3] FIG. 2 is a perspective view of a case included in the filter device. [Figure 4] FIG. 2 is a perspective view of a filter unit included in the filter device. [Diagram 5] FIG. 2 is a perspective view of a filter included in the filter unit. [Figure 6] FIG. 6 is a perspective view of the filter as seen from a different direction from that of FIG. 5. [Figure 7] FIG. 4 is a perspective view of a cleaning unit included in the filter unit. [Figure 8] FIG. 2 is a longitudinal sectional view of the filter device. [Figure 9] 9 is a cross-sectional view taken along the line AA in FIG. 8. [Figure 10] FIG. 9 is a cross-sectional view taken along the line BB in FIG. 8 . [Figure 11] 9 is a longitudinal sectional view of the filter device taken at a position different from that in FIG. 8. [Figure 12] 10 is a cross-sectional view taken at the same cutting position as FIG. 9, showing a state in which the scraping member of the cleaning unit is in an advanced position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic vertical cross-sectional right side view of a washing machine 1 according to an embodiment of the present invention. In FIG. 1, the direction perpendicular to the paper surface is referred to as the left-right direction X of the washing machine 1, the left-right direction in FIG. 1 is referred to as the front-rear direction Y of the washing machine 1, and the up-down direction in FIG. 1 is referred to as the up-down direction Z of the washing machine 1. In the left-right direction X, the back side of the paper surface of FIG. 1 is referred to as the left side X1, and the front side of the paper surface of FIG. 1 is referred to as the right side X2. In the front-rear direction Y, the left side of FIG. 1 is referred to as the front side Y1, and the right side of FIG. 1 is referred to as the rear side Y2. In the up-down direction Z, the upper side is referred to as the upper side Z1, and the lower side is referred to as the lower side Z2.

[0018] Washing machines 1 include vertical washing machines, drum washing machines, and twin-tub washing machines, but the following will explain washing machine 1 by taking as an example a vertical washing machine that omits the drying function and only performs a washing operation. Washing machine 1 includes a housing 2 that forms its outer shell, a washing tub 5 composed of an outer tub 3 and an inner tub 4 arranged in the housing 2, a rotor 6 housed in the inner tub 4, an electric motor 7 that generates a torque to rotate the inner tub 4 and the rotor 6, and a transmission mechanism 8 that switches the destination of the torque generated by motor 7.

[0019] The housing 2 is made of, for example, metal, and formed in a box shape. An opening 2B that connects the inside and outside of the housing 2 is formed on an upper surface 2A of the housing 2. A door 9 for opening and closing the opening 2B is provided on the upper surface 2A. A display operation unit 10 constituted by a touch panel or the like is provided on the upper surface 2A, for example, in an area Y1 in front of the opening 2B. The display operation unit may be configured separately into a display unit such as a liquid crystal panel, and an operation unit such as switches and buttons.

[0020] The outer tub 3 is formed in a bottomed cylindrical shape with an opening 3A formed at the upper end. The outer tub 3 is connected to the housing 2 via a hanging rod 11, which elastically supports the washing tub 5. The opening 3A is disposed directly below the opening 2B of the housing 2. Water is stored in the outer tub 3. The washing machine 1 includes a drainage channel 12 for discharging the water stored in the outer tub 3 to the outside of the machine, i.e., to the outside of the washing machine 1. The drainage channel 12 has an upper flow path 12A connected to the outer tub 3 from the lower side Z2, and a first lower flow path 12B and a second lower flow path 12C branched off from the upper flow path 12A.

[0021] The first downstream path 12B is drawn out of the machine. The second downstream path 12C merges with the first downstream path 12B inside the housing 2. The configuration of the second downstream path 12C will be described later. A drain valve 13 is provided midway along the first downstream path 12B, which is opened and closed to start and stop the discharge of water from the outer tub 3, i.e., drainage. When the drain valve 13 opens, the first downstream path 12B is opened, and drainage begins (see the solid arrow in FIG. 1). When the drain valve 13 closes, the first downstream path 12B is closed, and drainage stops.

[0022] The inner tub 4 has a central axis J extending in the vertical direction Z, is formed in a cylindrical shape with a bottom that is slightly smaller than the outer tub 3, and can accommodate laundry Q inside. An entrance 4A is formed at the upper end of the inner tub 4. The entrance 4A is in communication with the opening 3A of the outer tub 3 and the opening 2B of the housing 2 from the lower side Z2. A user of the washing machine 1 opens the door 9 to expose the opening 2B, the opening 3A, and the entrance 4A, and puts laundry Q in or takes out of the inner tub 4.

[0023] The inner tub 4 is coaxially housed within the outer tub 3 and is disposed vertically along the up-down direction Z. When housed within the outer tub 3, the inner tub 4 can rotate around the central axis J. The inner tub 4 is formed with a plurality of through-holes (not shown), and water within the outer tub 3 can move between the outer tub 3 and the inner tub 4 via the through-holes. A tubular support shaft 14 is provided on the bottom wall of the inner tub 4, extending downward Z2 along the central axis J and penetrating the bottom wall of the outer tub 3.

[0024] The rotor 6 is a so-called pulsator, formed in a disk shape with the central axis J as the circular center, and disposed on the bottom wall of the inner tub 4. The rotor 6 is provided with a rotating shaft 15 extending from the circular center to the lower side Z2 along the central axis J. The rotating shaft 15 is inserted into the hollow portion of the support shaft 14, and the lower end of the rotating shaft 15 is located on the lower side Z2 than the bottom wall of the outer tub 3.

[0025] The motor 7 has an output shaft 16 that protrudes to the upper side Z1 and rotates around a central axis J, and is disposed on the lower side Z2 of the inner tub 4. The transmission mechanism 8 is an electric clutch that is interposed between the lower end of each of the support shaft 14 and the rotating shaft 15 and the upper end of the output shaft 16. The transmission mechanism 8 selectively transmits the torque output from the output shaft 16 by the motor 7 to one or both of the support shaft 14 and the rotating shaft 15. When the torque is transmitted to the support shaft 14, the inner tub 4 rotates, and when the torque is transmitted to the rotating shaft 15, the rotor 6 rotates.

[0026] In relation to the supply of water to the outer tub 3 and the inner tub 4, the washing machine 1 includes a water supply passage 17 for supplying tap water from a faucet (not shown) into the inner tub 4. One end (not shown) of the water supply passage 17 is drawn out of the housing 2 and connected to the faucet. The other end of the water supply passage 17 faces the inlet / outlet 4A of the inner tub 4 from the upper side Z1 as a water supply port 17A arranged inside the housing 2. An openable and closable water supply valve 18 is provided in the portion of the water supply passage 17 arranged inside the housing 2.

[0027] Washing machine 1 includes control unit 19 configured with a microcomputer and the like. Motor 7, transmission mechanism 8, display operation unit 10, drain valve 13, and water supply valve 18 are electrically connected to control unit 19. The operation contents of display operation unit 10 by the user are input to control unit 19, and control unit 19 controls the display contents of display operation unit 10. Control unit 19 executes a washing operation for washing laundry Q in washing tub 5 by controlling the operation of motor 7, transmission mechanism 8, drain valve 13, and water supply valve 18. The washing operation includes a washing process for washing laundry Q in inner tub 4 of washing tub 5, a rinsing process for rinsing laundry Q after the washing process, and a spin-drying process for spin-drying laundry Q after the rinsing process.

[0028] In the washing step, control unit 19 first supplies water into washing tub 5 by opening water supply valve 18 for a predetermined time with drain valve 13 closed (see the dashed arrow in FIG. 1). Note that control unit 19 may supply bath water into washing tub 5 by operating a bath water pump (not shown) instead of opening water supply valve 18 when supplying water. Before or after water supply, the user may open door 9 and add detergent into inner tub 4 through opening / closing port 4A.

[0029] When the water level in the washing tub 5 rises to a predetermined level, the control unit 19 stops the water supply and then controls the motor 7 and the transmission mechanism 8 to rotate the rotor 6. As a result, the laundry Q in the inner tub 4 is washed by being agitated and having dirt broken down by the detergent. Finally, the control unit 19 drains the washing tub 5 by opening the drain valve 13 as part of the drainage process.

[0030] In the rinsing process, the control unit 19 first stores tap water in the washing tub 5 by opening the water supply valve 18 for a predetermined time with the drain valve 13 closed. After the water supply is completed, the control unit 19 controls the motor 7 and the transmission mechanism 8 to rotate the rotor 6. This rinses the laundry Q in the inner tub 4. In the rinsing process, the user may open the door 9 and add fabric softener through the opening / closing port 4A into the inner tub 4 before or after the water supply. The fabric softener permeates the laundry Q. Finally, the control unit 19 executes a draining process.

[0031] In the spin-drying process, the control unit 19 rotates the inner tub 4 at a predetermined spin-drying speed by controlling the motor 7 and the transmission mechanism 8 with the drain valve 13 open. As a result, the laundry Q in the inner tub 4 is spin-dried by the action of centrifugal force.

[0032] Next, the configuration of the second downstream path 12C of the drainage channel 12 will be described. The second downstream path 12C has an upstream area 12CA connected to the branching position of the upper path 12A, and a downstream area 12CB that is farther from the branching position than the upstream area 12CA. The upstream area 12CA extends from the branching position, for example, to the rear side Y2, then bends to the upper side Z1, and extends to the upper side Z1 along the peripheral wall of the outer tank 3 in the space 2C on the rear side Y2 of the outer tank 3 in the housing 2. The downstream area 12CB is disposed in the space 2C, for example, on the rear side Y2 of the upstream area 12CA, and extends to the lower side Z2 to merge with the first downstream path 12B.

[0033] The washing machine 1 includes an electric pump P provided in the upstream area 12CA and a filter device 20 provided in the downstream area 12CB. The filter device 20 captures foreign matter contained in the water flowing from the upper flow path 12A to the second downstream flow path 12C in the drainage channel 12. The foreign matter that the filter device 20 captures is paper hair, lint, dust, and dirt. Note that the dust and dirt also includes minute debris such as microplastics. Note that in the first downstream flow path 12B of the drainage channel 12, no configuration for restricting the flow of water is provided other than the drain valve 13.

[0034] In the following, the orientation of the filter device 20 is specified using the left-right direction X, the front-back direction Y, and the up-down direction Z of the washing machine 1, but the lateral directions of the filter device 20, i.e., the left-right direction X and the front-back direction Y, can be changed arbitrarily. The filter device 20 is disposed at the upper end of the space 2C in the housing 2. FIG. 2 is a perspective view of the filter device 20 as viewed from the front side Y1. The filter device 20 includes a box-shaped case 21 forming an outer shell thereof, and a filter unit 22 most of which is housed in the case 21.

[0035] 3 is a perspective view of the case 21 as viewed from the front side Y1. The case 21 integrally includes a semicircular bottom wall 21A bulging toward the rear side Y2, a vertical wall 21B rising from a front edge of the bottom wall 21A extending in the left-right direction X, and a curved wall 21C rising from an arc-shaped edge of the bottom wall 21A and spanning between the left and right ends of the vertical wall 21B. The space surrounded by the vertical wall 21B and the curved wall 21C and closed by the bottom wall 21A is an internal space 21D of the case 21. The internal space 21D is opened to the upper side Z1 by a semicircular opening 21E bordered by the upper edges of the vertical wall 21B and the curved wall 21C.

[0036] A cylindrical outlet passage 21F protruding to the lower side Z2 is provided at a position toward the right at the front end of the bottom wall 21A. The internal space of the outlet passage 21F is an outlet port 21G that communicates with the internal space 21D from the lower side Z2. A cylindrical inlet passage 21H protruding to the front side Y1 is provided at a position toward the upper side at the left end of the front surface of the vertical wall 21B. The internal space of the inlet passage 21H is an inlet port 21I that communicates with the internal space 21D from the front side Y1. A rib-shaped first engagement portion 21J extending in the left-right direction X is provided at the upper end of the front surface of the vertical wall 21B. A rib-shaped second engagement portion 21K that curves and extends in the left-right direction X is provided at the upper end of the inner circumferential surface of the curved wall 21C that faces the internal space 21D from the rear side Y2.

[0037] Fig. 4 is a perspective view of the filter unit 22 as viewed from the front side Y1. The filter unit 22 includes a filter 23 and a cleaning unit 24. Referring to Figs. 5 and 6 which are perspective views of the filter 23, the filter 23 has a tubular shape, specifically a cylindrical overall shape, with a cylindrical inner circumferential surface portion 23A having a central axis K extending vertically, i.e., in the up-down direction Z. The outer circumferential surface 23B of the filter 23 may be cylindrical like the inner circumferential surface portion 23A, or may be a square tube.

[0038] The filter 23 includes a cylindrical frame 25 that forms an outer shell thereof, and a mesh sheet 26 (see FIG. 6) attached to the frame 25. Note that the mesh sheet 26 is not shown in FIG. 5. In the following, the radial direction based on the central axis K is referred to as the radial direction R, and the circumferential direction around the central axis K is referred to as the circumferential direction S. Within the radial direction R, the direction approaching the central axis K is referred to as the radial inner direction R1, and the direction away from the central axis K is referred to as the radial outer direction R2.

[0039] The frame 25 integrally has a disk-shaped bottom wall 25A and a cylindrical circumferential wall 25B rising from the entire outer periphery of the bottom wall 25A. The space surrounded by the circumferential wall 25B and closed by the bottom wall 25A is an internal space 25C of the frame 25. The internal space 25C is also the internal space of the filter 23. The internal space 25C is opened to the upper side Z1 by a circular opening 25D bordered by the upper edge of the circumferential wall 25B. A cylindrical relay passage 25E protruding to the front side Y1 along a tangential direction T to the circumferential direction S is provided at approximately the center of the circumferential wall 25B in the vertical direction Z. The internal space of the relay passage 25E is an inlet 25F that communicates with the internal space 25C from the tangential direction T.

[0040] A plurality of through holes 25G are formed in each of the bottom wall 25A and the circumferential wall 25B. Eight through holes 25G are formed in the bottom wall 25A and are arranged at equal intervals in the circumferential direction S, and each through hole 25G is formed in an isosceles trapezoid shape that widens in the circumferential direction S toward the radially outward side R2. The plurality of through holes 25G formed in the circumferential wall 25B are distributed and arranged in an area of ​​the circumferential wall 25B avoiding the relay path 25E, and each through hole 25G is formed in a rectangular shape with rounded corners.

[0041] The through holes 25G are arranged in three vertical rows in the approximately first half region of the circumferential wall 25B, and are arranged in two vertical rows in the approximately second half region of the circumferential wall 25B. Eight through holes 25G in the lowest row are provided and are arranged at equal intervals over the entire area in the circumferential direction S of the lower end of the circumferential wall 25B. Four through holes 25G in the highest row in the approximately second half region of the circumferential wall 25B are the same size as the through holes 25G in the lowest row and are arranged at equal intervals in the circumferential direction S. The dimension in the vertical direction Z of the through holes 25G in the second row from the top in the approximately first half region of the circumferential wall 25B is about half that of the through holes 25G in the lowest row, and three through holes 25G in the second row are provided and arranged at the same height as the relay path 25E and are arranged at equal intervals in the circumferential direction S. The four uppermost through holes 25G in approximately the front half region of the circumferential wall 25B are the smallest overflow holes 25H in both the up-down direction Z and the circumferential direction S, and are arranged at equal intervals in the circumferential direction S. The upper ends of the uppermost through holes 25G in approximately the rear half region of the circumferential wall 25B are located at the same height as approximately the center of the overflow holes 25H in the up-down direction Z.

[0042] Ribs 25I for reinforcing the frame 25 are provided on the lower surface of the bottom wall 25A at positions avoiding the through-holes 25G and on the outer peripheral surface of the circumferential wall 25B at positions avoiding the relay paths 25E and the through-holes 25G. The ribs 25I extend in the circumferential direction S and the radial direction R on the lower surface of the bottom wall 25A (see FIG. 6), and extend in the up-down direction Z and the circumferential direction S on the outer peripheral surface of the circumferential wall 25B. A flange 25J is provided on the upper end of the circumferential wall 25B, protruding radially outward R2 over almost the entire area in the circumferential direction S. Notches 25K are provided in the flange 25J at a plurality of positions equally spaced apart in the circumferential direction S, by cutting the flange 25J in the up-down direction Z.

[0043] As shown in FIG. 6, the mesh sheet 26 is provided in all the through holes 25G except the overflow hole 25H in the uppermost stage of the circumferential wall 25B, and closes each of the through holes 25G to form the inner peripheral surface portion 23A (see FIG. 5) of the filter 23. Each mesh sheet 26 may be curved along the circumferential direction S. Each mesh sheet 26 has a countless number of filter holes 26A, which are minute through holes. Therefore, a plurality of filter holes 26A are distributed on the inner peripheral surface portion 23A of the filter 23. The overflow hole 25H is provided in an area Z1 above all of the filter holes 26A in the filter 23. Instead of the mesh sheet 26, a lattice (not shown) integrally formed with the frame 25 may be provided, and in this case, the gaps in the lattice function as the filter holes 26A. The size of filter holes 26A can be set arbitrarily, but is set to 10 to 20 μm when microplastics are to be captured, and is set to about 500 μm when microplastics are not to be captured.

[0044] 7 is a perspective view of the cleaning unit 24 as viewed from the front side Y1. The cleaning unit 24 includes a lid 30, a shaft 31 extending from the lid 30 to the lower side Z2, a rotor 32 rotatably supported by the shaft 31, a pair of scraping members 33 supported by the rotor 32, and weights 34 connected to each of the scraping members 33.

[0045] The lid 30 has a semicircular shape that is approximately the same in shape and size as the bottom wall 21A (see FIG. 3) of the case 21. A third engagement portion 30A is provided on a front edge of the lid 30 extending in the left-right direction X, and has a frame-like shape that is long in the left-right direction X and hangs down from the front edge.

[0046] The lower surface of the lid 30 is provided with an annular outer rib 30B that protrudes to the lower side Z2 while edging the outer peripheral edge of the lid 30. The outer rib 30B has a semicircular contour that is slightly smaller than the outer peripheral edge of the lid 30. The outer rib 30B has a circular arc-shaped edge that bulges to the rear side Y2, and is provided with a claw-shaped fourth engagement portion 30C that protrudes to the lower side Z2 and then bends to the rear side Y2. A packing 35 that edging the outer peripheral surface is attached to the outer peripheral surface of the outer rib 30B. The area surrounded by the outer rib 30B on the lower surface of the lid 30 is provided with an annular inner rib 30D that protrudes to the lower side Z2. The lower end of the inner rib 30D is located at a higher position than the lower end of the outer rib 30B, that is, on the upper side Z1. A cylindrical support portion 30E that protrudes to the lower side Z2 is provided at a position that coincides with the center of the inner rib 30D on the lower surface of the lid 30.

[0047] 8 is a vertical cross-sectional view of the filter device 20. The filter 23 is disposed in the case 21, and the lid 30 is attached so as to close the opening 21E of the case 21 and the opening 25D of the frame 25 of the filter 23 from the upper side Z1. The first engagement portion 21J of the case 21 engages with the third engagement portion 30A of the lid 30, and the second engagement portion 21K of the case 21 engages with the fourth engagement portion 30C of the lid 30, thereby fixing the lid 30 so as not to be removed unexpectedly (see FIG. 11).

[0048] On the underside of the lid 30, the outer rib 30B is sandwiched between the upper ends of the vertical wall 21B and the curved wall 21C of the case 21 and the upper end of the circumferential wall 25B of the frame 25 of the filter 23, and the upper end of the circumferential wall 25B is sandwiched between the outer rib 30B and the inner rib 30D (see also FIG. 11). In this state, the inner rib 30D and the filter 23 are arranged coaxially, so that the support part 30E provided on the underside of the lid 30 is arranged on the central axis K of the inner peripheral surface part 23A of the filter 23. A cylindrical support part 25L protruding to the upper side Z1 is provided at a position on the bottom wall 25A of the frame 25 of the filter 23 that coincides with the central axis K.

[0049] The gap between the case 21 and the outer rib 30B is filled by a packing 35. In addition, a claw-shaped positioning portion 30F protruding toward the radially inner side R1 is provided on the inner peripheral surface of the outer rib 30B (see FIG. 11). The positioning portion 30F comes into contact with the flange 25J at the upper end of the frame 25 from the lower side Z2, so that the filter 23 in the case 21 is positioned in a state in which the bottom wall 25A of the frame 25 is slightly raised from the bottom wall 21A of the case 21. Note that the user can disassemble the cleaning unit 24 and remove only the filter 23 by shifting the filter 23 in the circumferential direction S with respect to the lid 30 to align the positioning portion 30F with the notch 25K of the flange 25J (see FIG. 5) and then moving the filter 23 from the lid 30 to the lower side Z2. In the following, the shaft 31, the rotor 32, the scraping member 33, and the weight 34 will be described using the circumferential direction S and the radial direction R, with the lid 30 attached to the case 21 and the filter 23 as a reference.

[0050] The shaft 31 is, for example, a metal shaft, and is disposed on the central axis K within the filter 23, that is, in the internal space 25C of the frame 25 of the filter 23. The upper end of the shaft 31 is inserted into the support portion 30E of the lid 30, and the lower end is inserted into the support portion 25L of the frame 25 of the filter 23. To prevent the shaft 31 from coming off, a pair of upper and lower washers 36 are attached to the upper end of the shaft 31 so as to sandwich the support portion 30E therebetween. Another washer 37 is disposed on the support portion 25L.

[0051] The rotor 32 is disposed in the filter 23. The rotor 32 can be divided into an upper unit 40 and a lower unit 41. FIG. 9 is a cross-sectional view taken along the line AA in FIG. 8. The upper unit 40 integrally includes a disk-shaped base 40A disposed coaxially with the central axis K, an upper cylindrical portion 40B protruding from the center of the upper surface of the base 40A toward the upper side Z1, and a pair of upper guide portions 40C disposed on the upper surface of the base 40A with the upper cylindrical portion 40B sandwiched therebetween. Furthermore, the upper unit 40 integrally includes a lower cylindrical portion 40D protruding from the center of the lower surface of the base 40A toward the lower side Z2, and a plurality of blades 40E disposed on the lower surface of the base 40A so as to surround the lower cylindrical portion 40D (see FIG. 8).

[0052] At two locations on the outer periphery of the base 40A, which are 180 degrees apart in the circumferential direction S, one recess 40F recessed toward the radially inward direction R1 is formed. A pair of upper guide parts 40C are arranged at the same positions as each recess 40F in the circumferential direction S, and are arranged on the same line extending in the radial direction R. Each upper guide part 40C is a hollow body elongated in the radial direction R extending from the upper cylindrical part 40B to the recess 40F. The upper cylindrical part 40B may be regarded as an end part of the radially inward direction R1 of each upper guide part 40C. Each upper guide part 40C is provided with an inner space 40G located on the radially inward direction R1, an outer space 40H located on the radially outer side R2 of the inner space 40G, a partition wall 40I arranged between the inner space 40G and the outer space 40H, and an end wall 40J located on the radially outer side R2 of the outer space 40H.

[0053] The inner space 40G and the outer space 40H communicate with each other through a through hole 40K provided in the partition wall 40I. The outer space 40H is opened to the radially outer side R2 through a through hole 40L provided in the end wall 40J. The inner space 40G and the outer space 40H are opened to the upper side Z1. The upper unit 40 further includes a pair of upper covers 42 provided in accordance with the pair of upper guide parts 40C. The upper cover 42 is longitudinal in the radial direction R, and both ends of the upper cover 42 in the circumferential direction S are bent to the lower side Z2. The upper cover 42 is attached to the corresponding upper guide part 40C, sandwiches the upper guide part 40C from both sides in the circumferential direction S, and blocks the inner space 40G and the outer space 40H, which are internal spaces of the upper guide part 40C, from the upper side Z1 (see also FIG. 8). This prevents foreign matter from entering the inner space 40G and the outer space 40H. The upper cover 42 is detachable from the upper guide portion 40C by a known locking structure such as a screw or a snap fit.

[0054] The internal space of the upper cylindrical portion 40B and the internal space of the lower cylindrical portion 40D are in a continuous state and form an upper insertion hole 40M (see FIG. 8). The shaft 31 is inserted into the upper insertion hole 40M. This allows the entire rotating body 32 to rotate around the central axis K. The inner diameter of the upper cylindrical portion 40B is smaller than the inner diameter of the lower cylindrical portion 40D and is approximately the same as the outer diameter of the shaft 31, so that the rotating body 32, especially the approximately upper half of the rotating body 32, can rotate smoothly without rattling. A bearing (not shown) may be disposed between the inner peripheral surface of the upper insertion hole 40M and the shaft 31. The lower cylindrical portion 40D is provided with a locking hole 40N penetrating the lower cylindrical portion 40D in the radial direction R (see FIGS. 7 and 8). In this embodiment, two locking holes 40N are provided at two positions 180 degrees apart in the circumferential direction S.

[0055] The blades 40E are plate-like and have a substantially rectangular shape when viewed from the circumferential direction S, and are disposed away from the lower cylindrical portion 40D toward the radially outer side R2, and are connected to the outer periphery of the base 40A (see FIG. 7). The corners of both ends of the lower end of the blades 40E in the radial direction R are rounded. In this embodiment, eight blades 40E are disposed in a line at equal intervals in the circumferential direction S. Each blade 40E is disposed at a different position in the circumferential direction S from the recess 40F and the upper guide portion 40C of the base 40A. Each blade 40E is disposed above the lower half Z1 of the internal space 25C of the frame 25 of the filter 23 (see FIG. 8).

[0056] As shown in FIG. 9, the overflow hole 25H of the frame 25 of the filter 23 is disposed around the connection portion between the vertical wall 21B and the curved wall 21C of the case 21 in a plan view. Since the connection portion constitutes a corner of the case 21 in a plan view, a recess 21L recessed away from the overflow hole 25H is formed in the case 21. The recess 21L exists in a pair on the left and right, and forms a part of the internal space 21D of the case 21, particularly a part of the gap 21M between the filter 23 and the case 21. Note that the part of the case 21 that is out of the overflow hole 25H in the circumferential direction S is disposed along the curved wall 21C, so that the gap 21M in that part is narrower in the radial direction R than the recess 21L. In addition, the overflow hole 25H at the right end overlaps with the outflow port 21G of the bottom wall 21A of the case 21 in a plan view, so that the outflow port 21G is disposed directly below the overflow hole 25H, that is, at a position that coincides with the lower side Z2 and in the circumferential direction S.

[0057] Fig. 10 is a cross-sectional view taken along the line BB in Fig. 8. Inlet 25F of frame 25 of filter 23 is disposed at the same height as blades 40E in filter 23, and faces blades 40E from circumferential direction S, or more precisely, from a tangential direction T to the circumferential direction S. That is, inlet 25F faces blades 40E from the circumferential direction S or the tangential direction T. Also, inlet 21I of case 21 is disposed next to inlet 25F along the tangential direction T, and is in communication with inlet 25F.

[0058] Fig. 11 is a vertical cross-sectional view of the filter device 20 taken at a different position shifted 180 degrees in the circumferential direction S from that of Fig. 8. The lower unit 41 integrally includes a cylindrical portion 41A disposed directly below the upper cylindrical portion 40B of the upper unit 40, a locking portion 41B extending from the upper end of the cylindrical portion 41A to the upper side Z1, and a pair of lower guide portions 41C disposed on either side of the cylindrical portion 41A.

[0059] The internal space of the cylindrical portion 41A forms a lower through-hole 41D. The shaft 31 is inserted through the lower through-hole 41D. The inner diameter of the lower through-hole 41D is approximately the same as the outer diameter of the shaft 31, so that the rotor 32, particularly the lower half of the rotor 32, can rotate smoothly without rattling. A bearing (not shown) may be disposed between the inner peripheral surface of the lower through-hole 41D and the shaft 31.

[0060] The locking portion 41B is inserted into the internal space of the upper cylindrical portion 40B, i.e., the upper insertion hole 40M, from the lower side Z2 without contacting the shaft 31. A pair of claws 41E protruding in opposite directions toward the radially outer side R2 are provided at the upper end of the locking portion 41B, and are locked one by one into the locking holes 40N of the lower cylindrical portion 40D (see Figs. 7 and 8). This allows the lower unit 41 to be connected to the upper unit 40 so as to be rotatable together with the upper unit 40. The locking portion 41B is provided with a positioning portion 41F that contacts the lower cylindrical portion 40D from the lower side Z2 to position the lower unit 41 in the up-down direction Z relative to the upper unit 40.

[0061] The pair of lower guide parts 41C are arranged on the same straight line extending in the radial direction R. Each lower guide part 41C is a hollow body extending in an elongated manner from the cylindrical part 41A to the radially outer side R2. The cylindrical part 41A may be regarded as an end part of each lower guide part 41C on the radially inner side R1. Each lower guide part 41C is configured similarly to the upper guide part 40C of the upper unit 40. That is, the pair of lower guide parts 41C are arranged at the same position in the circumferential direction S as the pair of upper guide parts 40C. Furthermore, each lower guide part 41C is provided with an inner space 41G located on the radially inner side R1, an outer space 41H located on the radially outer side R2 of the inner space 41G, a partition wall 41I arranged between the inner space 41G and the outer space 41H, and an end wall 41J located on the radially outer side R2 of the outer space 41H.

[0062] The inner space 41G and the outer space 41H communicate with each other through a through hole 41K provided in the partition wall 41I. The outer space 41H is opened to the radially outer side R2 through a through hole 41L provided in the end wall 41J. The inner space 41G and the outer space 41H are opened to the lower side Z2. The lower unit 41 further includes a pair of lower covers 43 provided in accordance with the lower guide portion 41C. The lower cover 43 is elongated in the radial direction R, and both ends of the lower cover 43 in the circumferential direction S are folded to the upper side Z1. The lower cover 43 is attached to the corresponding lower guide portion 41C, sandwiches the lower guide portion 41C from both sides in the circumferential direction S, and blocks the inner space 41G and the outer space 41H, which are internal spaces of the lower guide portion 41C, from the lower side Z2 (see FIG. 8). This prevents foreign matter from entering the inner space 41G and the outer space 41H. The lower cover 43 is detachable from the lower guide portion 41C by a known locking structure such as a screw or a snap fit.

[0063] As described above, a pair of scraping members 33 are provided in accordance with the pair of upper guide portion 40C and lower guide portion 41C. The scraping members 33 are disposed at two locations 180 degrees apart in the circumferential direction S. The number of scraping members 33 can be changed as desired, and may be a single scraping member, or may be three or more scraping members disposed at equal intervals in the circumferential direction S. Each scraping member 33 includes a total of two slide pins 45 disposed in the internal spaces of the upper guide portion 40C and the lower guide portion 41C, a holder 47 fixed to the slide pins 45 via a bolt 46, and a brush 48 provided on the holder 47.

[0064] The slide pin 45 is cylindrical and extends in the radial direction R. Referring to the slide pin 45 at the upper left in Fig. 11, an annular inner flange portion 45A that protrudes one step from the outer circumferential surface of the slide pin 45 is provided at an end portion of the slide pin 45 on the radial inner side R1. An annular outer flange portion 45B that protrudes one step from the outer circumferential surface of the slide pin 45 is provided at a midpoint in the radial direction R of the slide pin 45, i.e., on the radial outer side R2 of the inner flange portion 45A. A screw hole 45C is formed in the slide pin 45, extending from the end face on the radial outer side R2 to the outer flange portion 45B.

[0065] The slide pin 45 arranged in the internal space of the upper guide part 40C is arranged across the internal space 40G and the external space 40H of the upper guide part 40C. In this slide pin 45, the internal flange part 45A is arranged in the internal space 40G, and the external flange part 45B is arranged in the external space 40H. This slide pin 45 is slidable in the radial direction R. When the slide pin 45 slides to the radially outward R2, the end part of the slide pin 45 on the radially outward R2 can protrude from the through hole 40L of the end wall 40J of the upper guide part 40C to the radially outward R2. In addition, since the external flange part 45B of the slide pin 45 faces the end wall 40J from the radially inward R1, the slide pin 45 is prevented from coming out of the internal space of the upper guide part 40C.

[0066] The slide pin 45 arranged in the internal space of the lower guide part 41C is arranged across the internal space 41G and the external space 41H of the lower guide part 41C. In this slide pin 45, the internal flange part 45A is arranged in the internal space 41G, and the external flange part 45B is arranged in the external space 41H. This slide pin 45 is slidable in the radial direction R. When the slide pin 45 slides to the radially outward R2, the end part of the slide pin 45 on the radially outward R2 can protrude from the through hole 41L of the end wall 41J of the lower guide part 41C to the radially outward R2. In addition, since the external flange part 45B of the slide pin 45 faces the end wall 41J from the radially inward R1, the slide pin 45 is prevented from coming out of the internal space of the lower guide part 41C.

[0067] The holder 47 is a box-shaped member that is long in the vertical direction Z and thin in the radial direction R, and its internal space is open to the radially outer side R2. Therefore, the holder 47 has a bottom wall 47A extending in the vertical direction Z, an upper wall 47B extending from the upper end of the bottom wall 47A to the radially outer side R2, a lower wall 47C extending from the lower end of the bottom wall 47A to the radially outer side R2, and a pair of side walls 47D (see FIG. 7) extending from both ends of the bottom wall 47A in the circumferential direction S to the radially outer side R2. The vertical dimension of the side walls 47D in the vertical direction Z is approximately the same as the vertical dimension of the internal space 25C of the frame 25 of the filter 23. The bottom wall 47A of the holder 47 is disposed to face the radially outer side R2 with respect to the upper guide portion 40C and the lower guide portion 41C that are at the same position as the holder 47 in the circumferential direction S.

[0068] The brush 48 is formed of bristles attached to the end faces of the radially outer side R2 of each of the pair of side walls 47D of the holder 47 and protruding in the radially outer side R2 (see also FIG. 7). Specifically, a predetermined number of bristles are arranged in bundles 48A at equal intervals in the vertical direction Z over almost the entire end face of the radially outer side R2 of each side wall 47D. Note that instead of the bundles 48A of bristles, the brush 48 may be formed of, for example, elastically deformable protrusions. Alternatively, instead of the brush 48, a wiper that is elongated in the vertical direction Z and protrudes from the side wall 47D in the radially outer side R2 may be used.

[0069] The weight 34 is a metal plate elongated in the vertical direction Z and tightly accommodated in the internal space of the holder 47. The bolts 46 penetrate the weight 34 and the bottom wall 47A of the holder 47 and are assembled one by one into the screw holes 45C of each slide pin 45, whereby the weight 34 and the holder 47 are fixed to the two upper and lower slide pins 45, completing each scraping member 33. Each scraping member 33 is supported by the upper guide portion 40C and the lower guide portion 41C of the rotating body 32 via the slide pins 45 in the filter 23, and can slide in the radial direction R in response to the sliding of the slide pins 45. The head 46A of the bolt 46 is disposed embedded in the weight 34 so as not to protrude from the end face of the radial outer side R2 of the weight 34.

[0070] The cleaning unit 24 further includes a biasing member 49 disposed in each of the internal spaces of the upper guide portion 40C and the lower guide portion 41C. The biasing member 49 is a coil spring extending in the radial direction R. In the upper guide portion 40C, the biasing member 49 is disposed in the outer space 40H and surrounds the slide pin 45, and is compressed between the end wall 40J and the outer flange portion 45B of the slide pin 45, thereby constantly biasing the slide pin 45 in the radially inward direction R1. In the lower guide portion 41C, the biasing member 49 is disposed in the outer space 41H and surrounds the slide pin 45, and is compressed between the end wall 41J and the outer flange portion 45B of the slide pin 45, thereby constantly biasing the slide pin 45 in the radially inward direction R1.

[0071] 8 to 11, all the slide pins 45 are in a state of being fully retracted to the radially inward R1. In this state, each scraping member 33 is in a retracted position away from the inner peripheral surface portion 23A of the filter 23 toward the central axis J, i.e., toward the radially inward R1, and in each scraping member 33, the holder 47 is disposed in a recess 40F at the same position in the circumferential direction S in the base 40A (see FIG. 9), and the bottom wall 47A of the holder 47 is in contact with the end wall 40J of the upper guide portion 40C and the end wall 41J of the lower guide portion 41C. Each scraping member 33 is constantly urged toward the retracted position by the urging member 49.

[0072] In the drainage process described above, the control unit 19 first operates the pump P with the drain valve 13 closed (see FIG. 1). Then, the pump P causes the water that has flowed down from the washing tub 5 into the upper flow path 12A of the drainage channel 12 to flow into the second lower flow path 12C. The water flowing through the second lower flow path 12C rises in the upstream area 12CA of the second lower flow path 12C, as shown by the dashed-dotted arrow in FIG. 1, and then flows into the case 21 of the filter device 20 from the inlet 21I of the case 21.

[0073] 10, water that has flowed into case 21 from inlet 21I travels straight to inlet 25F of filter 23 with almost no leakage on the way, and is taken into filter 23 from inlet 25F, and is sprayed onto blades 40E inside filter 23 from the above-mentioned tangential direction T. Then, the entire rotor 32 having blades 40E that have received the water taken into filter 23 from inlet 25F is rotated by the force of the water in one direction in the circumferential direction S, which in this embodiment is the clockwise direction in a plan view.

[0074] Furthermore, the water taken into the filter 23 from the inlet 25F flows out of the filter 23 from the filter hole 26A in the inner peripheral surface portion 23A of the filter 23, that is, into the gap 21M between the filter 23 and the case 21 in the case 21. When the water passes through the filter hole 26A, foreign matter contained in the water is captured and adheres to the inner peripheral surface portion 23A. In other words, the filter 23 captures the foreign matter contained in the water flowing out of the filter 23 from the filter hole 26A on the inner peripheral surface portion 23A. Note that the water flowing out from the inside of the filter 23 may pass through the mesh sheet 26 of the inner peripheral surface portion 23A not only to the radially outer side R2, but also to the mesh sheet 26 of the bottom wall 25A of the frame 25 to the lower side Z2.

[0075] The water that has flowed out of filter 23 flows out of case 21 from outlet 21G in bottom wall 21A of case 21, flows down in downstream region 12CB of second downstream path 12C, joins first downstream path 12B, and is discharged outside washing machine 1 (see the two-dot chain arrow in FIG. 1). When the amount of water flowing into filter 23 exceeds the amount of water flowing out of filter 23, the water in filter 23 overflows out of filter 23 from overflow hole 25H (see FIG. 8) provided at the upper end of frame 25, and flows out of case 21 from outlet 21G.

[0076] Each scraping member 33, which was in the retracted position up until now, slides radially outward R2 against the biasing force of the biasing member 49 due to the centrifugal force generated by the rotation of the rotor 32, and is disposed in the advanced position close to the inner peripheral surface portion 23A of the filter 23, as shown in FIG. 12. In each scraping member 33 in the advanced position, the brush 48 rotates as part of the rotor 32 and comes into contact with foreign matter on the inner peripheral surface portion 23A of the filter 23, thereby scraping off foreign matter from the inner peripheral surface portion 23A of the filter 23. When the brush 48 comes into contact with the foreign matter on the inner peripheral surface portion 23A, the rotation speed of the rotor 32 temporarily decreases, thereby reducing the centrifugal force, and each scraping member 33 retracts to the retracted position side due to the biasing force of the biasing member 49. In this way, each scraping member 33 can slide in the radial direction R between the retracted position and the advanced position.

[0077] Then, when the rotation speed of the rotor 32 is restored and the centrifugal force becomes large, each scraping member 33 advances again to the advance position and contacts the foreign matter on the inner peripheral surface portion 23A of the filter 23. In this way, the scraping member 33 repeatedly advances and retreats between the advance position and the retreat position during the rotation of the rotor 32 accompanying the drainage, and thereby contacts the foreign matter on the inner peripheral surface portion 23A of the filter 23 many times, thereby efficiently scraping off the foreign matter from the inner peripheral surface portion 23A of the filter 23. This makes it possible to suppress clogging of the filter 23 in the filter holes 26A and improve maintainability. In other words, even if the foreign matter is minute, such as microplastics or microfibers, this filter device 20 can continue to capture the foreign matter for a long time while peeling off the foreign matter attached to the inner peripheral surface portion 23A, so that a large amount of foreign matter can be captured. In particular, if the scraping member 33 is always in the advanced position, there is a risk that the rotation of the rotating body 32 will suddenly stop if the scraping member 33 gets caught on the inner surface portion 23A, but in this embodiment, the scraping member 33 is configured to be able to move forward and backward, so that the rotating body 32 can continue to rotate smoothly.

[0078] The blade 40E, which rotates the rotor 32 by receiving water taken into the filter 23 from the inlet 25F, is disposed on the upper side Z1 of the lower half of the internal space 25C of the filter 23 where water is likely to accumulate (see FIG. 11). Furthermore, the inlet 25F faces the blade 40E from the circumferential direction S or the tangential direction T (see FIG. 10). As a result, the blade 40E is less likely to receive resistance from the water that accumulates in the lower half of the internal space 25C of the filter 23, while efficiently receiving the water taken into the filter 23 from the inlet 25F, so that the rotor 32 can be rotated vigorously. Therefore, a large centrifugal force is generated, which makes it easier for the scraping member 33 to advance to the advanced position, so that the scraping member 33 can more efficiently scrape off foreign matter from the inner peripheral surface portion 23A of the filter 23. As a result, clogging of the filter 23 in the filter hole 26A can be further suppressed, and the maintainability can be further improved.

[0079] In addition, since the weight 34 connected to the scraping member 33 generates a large centrifugal force, the scraping member 33 can easily advance to the advanced position, so that the scraping member 33 can more efficiently scrape off foreign matter from the inner circumferential surface portion 23A of the filter 23. This can further suppress clogging of the filter 23 in the filter hole 26A, thereby further improving maintainability.

[0080] Even if filter 23 becomes clogged, water in filter 23 overflows from overflow hole 25H to the outside of filter 23 and flows out of case 21 from outlet 21G, so that water flowing in drainage channel 12 of washing machine 1 can be smoothly discharged to the outside of the machine. Furthermore, in case 21, recess 21L recessed away from overflow hole 25H is provided, and outlet 21G is disposed directly below overflow hole 25H (see FIG. 9), so that water overflowing from overflow hole 25H to the outside of filter 23 can be swiftly transferred from recess 21L to outlet 21G and discharged to the outside of the machine.

[0081] In this way, when the pump P operates with the drain valve 13 closing the first downstream flow path 12B, the water in the upper flow path 12A flows through the second downstream flow path 12C, foreign objects are captured by the filter device 20, and the water is discharged outside the machine. When the amount of water in the washing tub 5 decreases and the pump P becomes more likely to trap air, the control unit 19 stops the pump P and opens the first downstream flow path 12B with the drain valve 13. Then, water stops flowing into the filter device 20, and each scraping member 33 returns to the retracted position. In other words, the retracted position is the standby position of each scraping member 33.

[0082] When the first downstream path 12B opens, the remaining water in the washing tub 5 flows from the upper path 12A through the first downstream path 12B and is discharged outside the machine, so that noise caused by the pump P operating with air trapped in it can be suppressed and all the water in the washing tub 5 can be discharged. The control unit 19 determines that the water in the washing tub 5 is running low based on the detection value of a water level sensor (not shown) that detects the water level in the washing tub 5 and the elapsed time measured by a timer (not shown).

[0083] In the filter device 20, foreign matter peeled off from the inner peripheral surface portion 23A of the filter 23 accumulates in the internal space 25C of the frame 25 of the filter 23 from the bottom wall 25A side. In the filter device 20, at least the lid 30 of the filter unit 22 is exposed from the upper surface 2A of the housing 2 of the washing machine 1 (see FIG. 1). Therefore, as maintenance, the user can remove the filter unit 22 from the washing machine 1 by removing the first engagement portion 21J and the second engagement portion 21K of the case 21 from the third engagement portion 30A and the fourth engagement portion 30C of the lid 30, respectively, and disassemble it as described above to remove foreign matter in the filter 23. As described above, the filter device 20 can continue to capture foreign matter for a long time, so the user does not need to perform daily maintenance on the filter 23. The user can assemble the filter unit 22 and return it to the washing machine 1 by following the reverse procedure.

[0084] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the claims.

[0085] For example, the first downstream path 12B may be omitted in the drainage channel 12, and the drain valve 13 may also be omitted. In that case, the downstream path of the drainage channel 12 is only the second downstream path 12C, and a downstream region 12CB of the second downstream path 12C is led out of the washing machine 1. In addition, the first downstream path 12B and the second downstream path 12C may be led out of the washing machine 1 separately without merging. [Explanation of symbols]

[0086] 1. Washing machine 5 Washing tub 12 Drainage Channel 12A Upstream channel 12B 1st downstream passage 12C 2nd downstream passage 12CB downstream area 13 Drain valve 20 Filter device 21 cases 21G Outlet 21I Inlet 21L Recess 23 Filters 23A Inner peripheral surface section 25C interior space 25F intake port 25H Overflow hole 26A Filter hole 32 Rotating Body 33 Scraping member 34 Weight 40E Feather 49 Pressing member K center axis P-Pump Q Laundry R Radial direction S circumferential direction T Tangential direction Z1 upper side

Claims

1. A filter device for removing foreign matter from water in a drain of a washing machine, A case having an inlet and an outlet, the case allowing water in a drainage channel of the washing machine to flow into the case from the inlet and allowing water in the case to flow out from the outlet; a filter disposed within the case, the filter having a cylindrical inner peripheral surface portion having a vertically extending central axis and a plurality of filter holes distributed on the inner peripheral surface portion, the filter having an intake port for taking in water flowing into the case from the inlet into the filter, and capturing, at the inner peripheral surface portion, foreign matter contained in the water that is taken into the filter from the intake port and then flows out of the filter through the filter holes; a rotor including a plurality of blades spaced apart in a circumferential direction about the central axis, the plurality of blades being disposed within the filter, and the plurality of blades being rotated about the central axis by the force of water taken into the filter from the inlet; a scraping member disposed within the filter at a position offset in the circumferential direction around the central axis with respect to the plurality of blades, supported by the rotor, and configured to scrape off foreign matter from the inner peripheral surface portion, the scraping member being slidable in a radial direction with respect to the central axis between an advanced position approaching the inner peripheral surface portion and a retracted position moving away from the inner peripheral surface portion toward the central axis; a biasing member that biases the scraping member, which has slid to the advanced position as the rotating body rotates, toward the retracted position; The filter device, wherein the scraping member includes an upper end positioned above upper ends of the plurality of blades and a lower end positioned below lower ends of the plurality of blades.

2. The plurality of vanes include vanes disposed only above a lower half of an internal space of the filter, The filter device according to claim 1 , wherein the inlet faces the blade in a circumferential direction about the central axis or in a tangential direction relative to the circumferential direction.

3. The scraping member includes a scraping portion that contacts foreign matter on the inner circumferential surface portion and a holder that holds the scraping portion, The filter device according to claim 1 or 2, wherein the holder has a different shape than the vanes.

4. an overflow hole for allowing water in the filter to overflow outside the filter is provided in a region above the filter hole in the filter, A recess is provided in the case so as to be spaced apart from the overflow hole, The filter device according to any one of claims 1 to 3, wherein the outlet is disposed directly below the overflow hole.

5. A washing tub for storing laundry; A drainage path having an upper flow path connected to the washing tub and a first lower flow path and a second lower flow path branched from the upper flow path; A drain valve that opens and closes the first downstream path; a pump provided in the second downstream flow path for causing the water in the upstream flow path to flow into the second downstream flow path; and the filter device according to any one of claims 1 to 4, which is provided in a downstream region of the second downstream path that is farther from the upstream path than the pump.

Images