Dishwasher and method for controlling a dishwasher

Abstract

This disclosure provides a dishwasher that can reduce the height of the filter while suppressing contamination of the washing water and improving ease of maintenance, as well as a control method for the dishwasher. [Solution] The dishwasher in this disclosure comprises a washing tank for containing items to be washed, a spray unit for spraying washing water into the washing tank, a first filter provided at the bottom of the washing tank, and a second filter formed in a cylindrical shape with sides aligned in the vertical direction, partitioning a first contamination retention space on its inside. The first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space. Outside the first contamination retention space, a first space is formed that communicates with the spray unit via a washing path. Below the first contamination retention space, a second contamination retention space is formed, and the first contamination retention space and the second contamination retention space communicate with each other via the second opening.

Description

Technical Field

[0001] The present disclosure relates to a dishwasher and a control method for a dishwasher.

Background Art

[0002] Patent Document 1 discloses a dishwasher capable of maintaining predetermined washing performance with a small amount of water. This dishwasher includes a food residue filter having: a first filter portion provided at a substantially central portion; a boundary portion provided substantially vertically upward from a peripheral edge of the first filter portion; and a second filter portion 33 having through holes larger than those of the first filter portion.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] The present disclosure provides a dishwasher and a control method for a dishwasher, which are configured to reduce the height dimension of a filter, while suppressing contamination of washing water and improving maintainability.

Means for Solving the Problem

[0005] The dishwasher in this disclosure comprises a washing tank for containing items to be washed, a spray unit for spraying washing water into the washing tank, a first filter provided at the bottom of the washing tank, and a second filter formed in a cylindrical shape with sides aligned in the vertical direction, partitioning a first contamination retention space on its inside. The first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space. Outside the first contamination retention space, a first space is formed that communicates with the spray unit via a washing path. Below the first contamination retention space, a second contamination retention space is formed, and the first contamination retention space and the second contamination retention space communicate with each other via the second opening.

[0006] The dishwasher control method in this disclosure comprises a washing tank for containing items to be washed, a spray unit for spraying washing water into the washing tank, a first filter provided at the bottom of the washing tank, and a second filter formed in a cylindrical shape with sides aligned in the vertical direction and partitioning a first contamination retention space on its inside, wherein the first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space, a first space is formed outside the first contamination retention space that communicates with the spray unit via a washing path, a second contamination retention space is formed below the first contamination retention space, the first contamination retention space and the second contamination retention space communicate with each other via the second opening, and a washing pump is provided in the dishwasher to transport the washing water from the first space to the spray unit via the washing path, wherein the control unit provided in the dishwasher temporarily reduces the rotation speed of the washing pump during the washing process for washing the items to be washed. [Effects of the Invention]

[0007] The dishwasher and control method for the dishwasher described herein can cause residues and other debris adhering to the second filter to settle in the first contamination retention space and be collected in the second contamination retention space, thereby suppressing blockage of the second filter. As a result, the height dimension of the second filter can be reduced while suppressing contamination of the washing water and improving ease of maintenance. [Brief explanation of the drawing]

[0008] [Figure 1] Schematic side view of a dishwasher according to Embodiment 1 [Figure 2] Plan view of the base member [Figure 3] Plan view of the base member [Figure 4] View of section IV-IV in Figure 3 [Figure 5] VV cross-sectional view in Figure 3 [Figure 6] Diagram showing the configuration of the dishwasher control system. [Figure 7] A diagram showing the change in the rotation speed of the cleaning pump during the cleaning process. [Figure 8] This figure shows the change in the rotation speed of the cleaning pump after the operation control unit according to Embodiment 2 temporarily reduces the rotation speed of the cleaning pump during the cleaning process, and then restores the rotation speed. [Modes for carrying out the invention]

[0009] (Knowledge and other information that formed the basis of this disclosure) At the time the inventors conceived this disclosure, dishwasher technology generally involved circulating wash water while washing items in the washing tank, in order to conserve water resources. Therefore, in the industry, a common problem was that the wash water would be contaminated by residues attached to the items being washed, and it was common to design products that included a filter to remove residues from the circulating wash water. Under these circumstances, the inventors, inspired by the fact that if a mechanism to collect residues using a flat filter was provided, as in Reference Document 1, the filter area would be small, making the filter prone to clogging and resulting in insufficient residue collection, they conceived the idea of ​​increasing the size of the filter. The inventors then discovered that if the size of the filter was made too large, it would be necessary to secure space for the mechanism, making it difficult to secure sufficient volume for the washing tank. The inventors then arrived at the subject matter of this disclosure in order to solve these problems. Therefore, this disclosure provides a dishwasher that can reduce the height of the filter while suppressing contamination of the washing water and improving ease of maintenance.

[0010] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The attached drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0011] (Embodiment 1) Embodiment 1 will be described below with reference to the drawings.

[0012] [1-1. Structure] [1-1-1. Overall Structure] Figure 1 is a schematic side view of a dishwasher 1 according to Embodiment 1. The dishwasher 1 is a pull-out type built-in dishwasher installed, for example, in a system kitchen, and is equipped with a pull-out washing tub 50. Hereinafter, the direction in which the washing tub 50 is pulled out will be considered the front, and the direction to the left of a person looking at the dishwasher 1 from the front will be considered the left direction. In the figure, X represents the left direction, Y represents the front direction, and Z represents the upward direction.

[0013] The dishwasher 1 has a housing 10 that is installed inside a system kitchen or the like. The housing 10 is a box-shaped component that opens to the front. The opening of the housing 10 is closed from the front by a door 11.

[0014] A washing tub 50 is housed inside the housing 10. The washing tub 50 is a box-shaped structure formed with an upward opening 51. Inside the washing tub 50, a washing basket 30 for placing an object to be washed D such as a plate or a cup is provided. The washing tub 50 is connected to a door body 11. In the present embodiment, the washing tub 50 includes a side member 52 constituting a side surface of the washing tub 50, and a bottom member 53 constituting a bottom portion 50A of the washing tub 50.

[0015] A first rail 41 extending forward and backward is provided on the outer surface in the left-right direction of the washing tub 50. The washing tub 50 is supported so as to be movable in the front-rear direction relative to the housing 10 by the first rail 41 being supported by a second rail 13 provided on the inner surface of the housing 10.

[0016] As shown in Fig. 1, when the washing tub 50 moves rearward and is pushed into the housing 10, the door body 11 closes the opening of the housing 10. Further, the washing tub 50 is drawn forward to the outside such as a sink through the opening of the housing 10. When the washing tub 50 is drawn forward, the object to be washed D can be put into and taken out of the washing tub 50 through the opening 51.

[0017] When the washing tub 50 is housed in the housing 10, the opening 51 of the washing tub 50 is closed by a lid portion 15 provided on the housing 10. An annular rubber lid-side contact portion 16 is attached to the lower surface of the lid portion 15. The lid-side contact portion 16 seals the washing tub 50 by contacting the periphery of the opening 51. The lid portion 15 is attached to the housing 10 so as to be movable up and down via a parallel link mechanism 17 or the like. The lid portion 15 is configured to move downward to close the opening 51 when the washing tub 50 is housed in the housing 10, and move upward to avoid interference with the washing tub 50 when the washing tub 50 is drawn out.

[0018] A required amount of washing water such as tap water is supplied into the washing tub 50 from a branch faucet on a system kitchen or the like via a water supply path (not shown) including a water supply hose, a water supply pump, a water supply valve and the like. The washing water supplied into the washing tub 50 accumulates at the bottom portion 50A of the washing tub 50.

[0019] The dishwasher 1 has a washing pump 43. The washing pump 43 is a pump that transports the washing water accumulated at the bottom 50A of the washing tank 50 to the washing nozzles 45 via a washing path 44. The washing path 44 is the path through which the washing water flows and is connected to the washing nozzles 45.

[0020] The cleaning nozzle 45 is located inside the cleaning tank 50, below the cleaning basket 30, and is positioned near the center of the cleaning tank 50 in a plan view. The cleaning nozzle 45 has multiple nozzles for ejecting cleaning water. Each nozzle opens upward. The cleaning nozzle 45 is configured to rotate about an axis in the vertical direction, either by the power of a motor or the recoil when the cleaning water is ejected. The cleaning nozzle 45 cleans the objects to be cleaned D placed in the cleaning basket 30 by rotating while ejecting cleaning water upward from each nozzle. The cleaning nozzle 45 corresponds to an example of a "spray unit" in this disclosure.

[0021] Furthermore, the cleaning nozzle 45 is provided with a center nozzle 45A. The center nozzle 45A has multiple nozzles for spraying cleaning water. The center nozzle 45A is provided with a water distribution mechanism. The water distribution mechanism is a mechanism that switches between nozzles that spray cleaning water and nozzles that do not spray cleaning water each time the supply of cleaning water to the cleaning nozzle 45 or the amount of water supplied is switched. For example, the water distribution mechanism may include a nozzle valve that reciprocates up and down according to the supply of cleaning water to the cleaning nozzle 45 and the amount of water supplied, as pushed up by the cleaning water, and a cam that has multiple inclined surfaces inclined in the vertical direction. In this case, for example, each time the nozzle valve reciprocates up and down, the nozzle valve rotates by a predetermined angle about the vertical axis due to contact between the nozzle valve and the inclined surface of the cam, and the nozzle that is blocked from reaching the cleaning water by the nozzle valve is switched.

[0022] The dishwasher 1 is equipped with a drainage path 46 (not shown) for draining washing water from the washing tank 50. The drainage path 46 is the path through which the washing water flows to a drain pipe or the like installed in the kitchen. The drainage path 46 consists of a drain pump 47 and a drain hose, etc. The drain pump 47 is a pump that transports the washing water accumulated at the bottom 50A of the washing tank 50 to the drain pipe or the like via the drainage path 46.

[0023] [1-1-2. Configuration of the area near the bottom of the washing tank] Figure 2 is a plan view of the bottom member 53. As shown in Figure 2, a bottom surface portion 54 is formed on the bottom member 53. The bottom surface portion 54 has a substantially horizontal plate-like structure and constitutes the bottom surface of the washing tank 50.

[0024] A nozzle shaft 54A is formed on the bottom surface 54, protruding upward. The nozzle shaft 54A is a hollow cylindrical structure that protrudes upward from the bottom surface 54. A cleaning nozzle 45 is rotatably attached to the upper end of the nozzle shaft 54A. Cleaning water flows inside the nozzle shaft 54A. The nozzle shaft 54A constitutes part of the cleaning path 44.

[0025] A bottom opening 54B is formed in the bottom surface 54. The bottom opening 54B is an opening formed in the front right part of the bottom surface 54. The bottom opening 54B is closed by a concave member 55. The concave member 55 is a member having a recess 56 that is recessed downwards. The concave member 55 is attached to the bottom surface 54 with an edge 55A provided on the outer circumference of the recess 56 in contact with the edge of the bottom opening 54B. As a result, the recess 56 is recessed downwards from the bottom surface 54 through the bottom opening 54B.

[0026] A first partition member 60 is installed inside the recess 56. The first partition member 60 is a plate-shaped member made of resin. The first partition member 60 is provided with a first partition portion 61 which is substantially circular in plan view, and a second partition portion 62 which surrounds the first partition portion 61 in plan view. The first partition portion 61 and the second partition portion 62 are spaced apart radially from the first partition portion 61 and are connected to each other via a plurality of connecting portions 63. In the first partition member 60, a lower opening 64 is formed between the first partition portion 61 and the second partition portion 62. The lower opening 64 is composed of a plurality of openings 65 which radiate outwards from the outer edge of the first partition portion 61 toward the inner edge of the second partition portion 62. As shown in Figure 2, in plan view, at least a portion of each opening 65 is configured not to overlap with the first partition portion 61. Furthermore, in this embodiment, the opening 65 is formed over substantially the entire circumference of the outer edge of the first partition 61. The lower opening 64 corresponds to an example of the "second opening" in this disclosure.

[0027] Furthermore, a second partition member 67 is attached to the inside of the recess 56. The second partition member 67 is a plate-shaped member made of resin.

[0028] Figure 3 is a plan view of the bottom member 53, showing the bottom member 53 with the perforated filter 57 attached. The perforated filter 57 is a plate-shaped filter with numerous small holes, and is configured to allow washing water to pass through. The perforated filter 57 closes the recess 56 of the concave member 55 from above. The perforated filter 57 is provided substantially flush with the bottom surface 54. In this embodiment, the perforated filter 57 is made of stainless steel. However, the perforated filter 57 may be made of a material other than stainless steel, such as resin. The perforated filter 57 corresponds to an example of the "third filter" in this disclosure.

[0029] A filter insertion opening 57A is formed in the punching filter 57. The filter insertion opening 57A is a circular opening in a plan view. A mesh filter 58 is inserted into the filter insertion opening 57A from above.

[0030] Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3, showing the configuration near the recess 56 in a cross-section perpendicular to the front-to-back direction and passing through the center of the mesh filter 58. The mesh filter 58 is a hollow cylindrical filter with side surfaces 58A formed along the vertical direction. The mesh filter 58 corresponds to an example of the "second filter" in this disclosure.

[0031] The mesh filter 58 comprises a frame 58B and a mesh member 58C. The frame 58B is a member made of resin. The frame 58B is formed in a hollow cylindrical shape with multiple openings on its side.

[0032] The mesh member 58C is a sheet-like member made of plain-woven fibers. The mesh member 58C is configured to allow cleaning water to pass through. The side surface 58A of the mesh filter 58 is formed by the mesh member 58C covering the opening on the side surface of the frame 58B. The mesh member 58C may be made of stainless steel or the like instead of fibers. Alternatively, the mesh filter 58 may have a sheet-like member on its side surface 58A that is configured to allow cleaning water to pass through by punching or etching, instead of the mesh member 58C.

[0033] The mesh filter 58 is attached to the punching filter 57 by hooking its edge portion 58D, which extends radially outward from the upper end of the frame 58B, onto the edge of the filter insertion opening 57A. In addition, the frame 58B has a projection 58E that protrudes radially inward from its side.

[0034] A grid filter 59 is installed inside the mesh filter 58. The grid filter 59 is a component made of resin. The grid filter 59 has a substantially cylindrical side surface 59A that extends in the vertical direction, and a bottom surface 59B that closes the lower end of the side surface 59A. As a result, an upper contamination retention space S1, which is an upward-opening space, is formed inside the grid filter 59. An upper opening 59C is formed in the side surface 59A. The upper opening 59C is composed of a plurality of openings 59D formed in the side surface 59A. The upper contamination retention space S1 communicates with the space outside the side surface 59A through the upper opening 59C. The grid filter 59 corresponds to an example of the "first filter" in this disclosure. The upper opening 59C corresponds to an example of the "first opening" in this disclosure.

[0035] Furthermore, an edge portion 59E is formed at the upper end of the side surface 59A, extending radially outward from the grid filter 59. Additionally, a projection 59F is formed on the outer surface of the side surface 59A, projecting radially outward. The grid filter 59 is inserted inside the mesh filter 58, and is attached to the mesh filter 58 by the projection 59F catching on the projection 58E from below and the edge portion 59E catching on the projection 58E from above. The grid filter 59 also has a knob 59G that projects upward from the inside of the side surface 59A.

[0036] As described above, the perforated filter 57, mesh filter 58, and grid filter 59 are each configured to allow washing water to pass through. The perforated filter 57 offers greater resistance to washing water passage compared to the mesh filter 58 and grid filter 59. In this embodiment, the perforated filter 57 has a smaller opening area per unit area than the mesh filter 58 and grid filter 59, resulting in greater resistance to washing water passage.

[0037] Furthermore, each filter 57, 58, and 59 captures residue and other particles from the washing water. The size of the residue and other particles that can be captured by each filter 57, 58, and 59 differs. Specifically, the perforated filter 57 can capture residue and other particles smaller than those that the grid filter 59 can capture. Similarly, the mesh filter 58 can capture residue and other particles smaller than those that the perforated filter 57 can capture.

[0038] As shown in Figure 4, an inflow space S2 is formed inside the recess 56, partitioned by the second partition member 67. The inflow space S2 is part of the cleaning path 44 and is located at the uppermost part of the cleaning path 44 in the direction of the flow of cleaning water from the cleaning pump 43. The second partition member 67 is positioned outside the mesh filter 58 in the radial direction. Therefore, the inflow space S2 is formed outside the mesh filter 58 in the radial direction.

[0039] The second partition member 67 has a peripheral wall portion 68 that runs vertically. The peripheral wall portion 68 is positioned to the left of the side surface 58A of the mesh filter 58 and curves along the side surface 58A in a plan view (see Figure 2). The peripheral wall portion 68 partitions the inflow space S2 from the right side. The second partition member 67 also has an upper surface portion 69 that extends to the left from the upper end of the peripheral wall portion 68. The upper surface portion 69 partitions the inflow space S2 from above.

[0040] The inflow space S2 is connected to the cleaning pump 43 via a connection port 55B, which is an opening formed in the concave member 55. In this embodiment, a heater 48 for heating the cleaning water is provided inside the casing 43A that forms the outer surface of the cleaning pump 43.

[0041] Figure 5 is a cross-sectional view of the VV section in Figure 3, showing the configuration near the recess 56 in a cross-section perpendicular to the left-right direction and passing through the center of the mesh filter 58.

[0042] Inside the recess 56, an intermediate contamination retention space S3 is formed, partitioned by a mesh filter 58, a grid filter 59, and a first partition member 60. The intermediate contamination retention space S3 is partitioned inside the side surface 58A of the mesh filter 58 in the radial direction. The intermediate contamination retention space S3 is partitioned below the grid filter 59. Furthermore, the intermediate contamination retention space S3 is partitioned above the first partition portion 61 and the second partition portion 62 of the first partition member 60. The intermediate contamination retention space S3 corresponds to an example of the "first contamination retention space" in this disclosure.

[0043] A lower contamination retention space S4 is formed inside the recess 56. The lower contamination retention space S4 is a space partitioned off below the first partition member 60. A portion of the lower contamination retention space S4 is located below the middle contamination retention space S3. In this embodiment, a projection 55J is provided inside the lower contamination retention space S4, projecting upward from the portion of the concave member 55 that constitutes the bottom surface of the lower contamination retention space S4. The projection 55J is located below the first partition 61, and substantially the entire projection 55J overlaps with the first partition 61 in a plan view. In other words, the projection 55J is provided in a position opposite to the first partition 61. For example, when a long, thin foreign object such as a toothpick enters the lower contamination retention space S4 through the opening 65 of the lower opening 64, the projection 55J can prevent the foreign object from getting caught. Unlike this embodiment, in order to secure the volume of the lower contamination retention space S4, the portion of the concave member 55 that constitutes the bottom surface of the lower contamination retention space S4 may be formed flat, and a protruding portion 55J may not be formed. The lower contamination retention space S4 is connected to the drainage path 46 via a connection port 55C, which is an opening formed in the concave member 55. In this embodiment, the lower contamination retention space S4 is connected to the suction side of the drainage pump 47 via the connection port 55C. In detail, the connection port 55C is formed in the connection portion 55E. The connection portion 55E has a cylindrical front portion 55F that extends in the front-rear direction, and a cylindrical rear portion 55G that is connected to the rear side of the front portion 55F and extends in the front-rear direction. The rear portion 55G has a larger diameter than the front portion 55F. The above-mentioned connection port 55C is formed at the rear end of the rear portion 55G. Furthermore, a drainage inlet 55H is attached to the upper part of the edge of the opening at the front end of the front section 55F. The drainage inlet 55H has a plate-like structure that covers the opening at the front end of the front section 55F from above and in front. The drainage inlet 55H limits the height of the cleaning water drawn into the drainage pump 47 via the connection section 55E, thereby suppressing air entrapment in the drainage pump 47. The lower contamination retention space S4 corresponds to an example of the "second contamination retention space" in this disclosure.

[0044] Furthermore, the lower contamination retention space S4 is connected to the middle contamination retention space S3 via the lower opening 64. As shown in Figure 5, each opening 65 of the lower opening 64 is inclined downward from the outer edge of the first partition 61 toward the inner edge of the second partition 62. The first partition 61 is located above the second partition 62. The first partition 61 is inclined downward toward each opening 65. The second partition 62 is inclined downward toward each opening 65.

[0045] As shown in Figures 4 and 5, a third partition portion 66 is formed in the first partition member 60. The third partition portion 66 has a peripheral wall portion 66A that rises upward from the rear of the second partition portion 62. The peripheral wall portion 66A is positioned at a distance from the side surface 58A of the mesh filter 58 towards the rear. In addition, the peripheral wall portion 66A is curved along the side surface 58A in a plan view (see Figure 2). Furthermore, the third partition portion 66 has an upper surface portion 66B that extends rearward from the upper end of the peripheral wall portion 66A.

[0046] Furthermore, the space S5 is partitioned inside the recess 56 by the punching filter 57, the mesh filter 58, the first partition member 60, and the second partition member 67. Space S5 is the space surrounding the mesh filter 58 in a plan view. Space S5 is partitioned below the punching filter 57 from the space inside the recess 56. Space S5 is partitioned outside the side surface 58A of the mesh filter 58 in the radial direction. Space S5 is partitioned by the second partition member 67 on the opposite side of the inflow space S2, i.e., above and to the right of the inflow space S2. Space S5 is partitioned by the first partition member 60 on the opposite side of the lower contamination retention space S4, i.e., above and in front of the lower contamination retention space S4. Space S5 corresponds to an example of the “first space” in this disclosure.

[0047] As shown in Figure 4, the inflow space S2 and space S5 communicate with each other via the inlet 44A of the washing path 44. The inlet 44A is formed between the lower end of the peripheral wall portion 68 and the concave member 55, and is an opening that connects the inflow space S2 and space S5 in the left-right direction. The inlet 44A is located below the upper opening 59C of the grid filter 59. More specifically, the upper end of the inlet 44A is located below the lower ends of all the openings 59D of the upper opening 59C. The inlet 44A is also located above the lower opening 64. More specifically, the lower end of the inlet 44A is located above the upper ends of each opening 65 of the lower opening 64. Furthermore, the upper ends of the first partition portion 61 and the second partition portion 62 are located below the lower end of the inlet 44A. Each opening 65 of the lower opening 64 is provided at a position lower than the inlet 44A for at least half of its vertical dimension. In this embodiment, the entirety of each opening 65 of the lower opening 64 is located below the lower end of the inlet 44A. Furthermore, the inlet 44A is divided into multiple openings by a plurality of protrusions 67A. The plurality of protrusions 67A have a comb-like structure that extends downward from the inflow space S2 side of the peripheral wall portion 68.

[0048] As shown in Figures 4 and 5, the concave member 55 has a peripheral wall portion 55D facing the space S5. The peripheral wall portion 55D is formed at a position radially outward from the side surface 58A of the mesh filter 58 and extends in the vertical direction. In a plan view, the peripheral wall portion 55D is curved in an arc along the side surface 58A.

[0049] The peripheral wall portions 55D, 66A, and 68 formed on the concave member 55, the first partition member 60, and the second partition member 67 are connected to each other substantially flush with each other, and in a plan view, they surround the mesh filter 58 and form a cylindrical curved surface that partitions the space S5 from the outside (see Figure 2). Also, as shown in Figures 4 and 5, a vertical gap G is formed between the upper ends of the peripheral wall portions 55D, 66A, and 68 and the punching filter 57. In this embodiment, the size of the vertical gap G is 10 mm or more over a range of more than half the circumference of the cylindrical curved surface formed by the peripheral wall portions 55D, 66A, and 68. In other words, the upper edges of the peripheral wall portions 55D, 66A, and 68 are spaced 10 mm or more below the punching filter 57 over a range of more than half the circumference of the peripheral wall portions 55D, 66A, and 68. Furthermore, the size of the gap G is not limited to 10 mm, but is preferably smaller than the height dimension of the surrounding cylindrical filter, and the gap G is configured to be between 1 / 3 and 1 / 2 of the height dimension of the mesh filter 58 and the grid filter 59. With such a configuration, a pressure distribution that reduces the horizontal flow velocity in the middle contamination retention space S3 is likely to occur, and since a large amount of washing water passes through the path to the upper contamination retention space S1, a large amount of contamination can be collected in the upper contamination retention space S1.

[0050] [1-1-3. Control System Configuration] Figure 6 shows the configuration of the control system of dishwasher 1. Dishwasher 1 includes a control unit 90.

[0051] The control unit 90 is connected to each component of the dishwasher 1, such as the washing pump 43, drainage pump 47, and heater 48, and controls the operation of each component.

[0052] The control unit 90 includes a processor 91 and a storage medium 92. The processor 91 is composed of, for example, a CPU (Central Processing Unit) or an MPU (Micro-Processing Unit).

[0053] The storage medium 92 is composed of, for example, a hard disk, flash memory, or optical disc. The storage medium 92 stores the control program 93. The processor 91 functions as an operation control unit 94 by reading and executing the control program 93 stored in the storage medium 92. The operation control unit 94 controls the washing pump 43, the drain pump 47, the heater 48, etc., to operate the dishwasher 1.

[0054] [1-2. Operation] The operation of the dishwasher 1, configured as described above, will be explained below.

[0055] [1-2-1. Overview of Dishwasher Operation] The operation control unit 94 starts operating the dishwasher 1 when it detects an operation to start operation via an operation unit (not shown) or when the start time of a pre-set scheduled operation is reached. At the start of operation of the dishwasher 1, the operation control unit 94 drives the drain pump 47 to drain any wash water remaining in the recesses 56, etc., from the previous operation. After that, the operation control unit 94 stops the operation of the drain pump 47.

[0056] Next, the operation control unit 94 opens a water supply valve (not shown) and fills the washing tank 50 with washing water via the water supply path. After filling the washing tank 50 with a predetermined amount of washing water, the operation control unit 94 closes the water supply valve to stop the supply of washing water to the washing tank 50.

[0057] Following the supply of washing water to the washing tank 50, the operation control unit 94 starts the washing process. The washing process is a step in the operation of the dishwasher 1 in which washing water containing detergent is sprayed onto the items to be washed D to wash away residue and other contaminants attached to the items D. During the washing process, the operation control unit 94 drives the washing pump 43 and heats the washing water with the heater 48. During this time, the drain pump 47 stops operating. The detergent used in the washing process may be added to the washing tank 50 by the user before the dishwasher 1 starts operation, or it may be automatically added at the start of the washing process by controlling an automatic dispensing device (not shown) controlled by the operation control unit 94.

[0058] After the washing process is complete, the operation control unit 94 stops the washing pump 43 and drives the drain pump 47 to drain the washing water accumulated at the bottom 50A of the washing tank 50. Then, the operation control unit 94 executes the rinsing process. In the rinsing process, the operation control unit 94 repeats the supply of washing water to the washing tank 50 via the water supply valve, the driving of the washing pump 43, and the driving of the drain pump 47 a number of times to rinse off the detergent adhering to the items to be washed D. After the rinsing process is complete, the operation control unit 94 terminates the operation of the dishwasher 1. Alternatively, after the rinsing process is complete, the operation control unit 94 may operate a drying heater and fan to dry the washing tank 50 and the items to be washed D.

[0059] [1-2-2. Details of the flow of washing water in the washing process] Next, the flow of cleaning water in the cleaning process will be explained. In the cleaning process, the cleaning water in the cleaning tank 50 circulates between the cleaning path 44 and the cleaning tank 50 due to the operation of the cleaning pump 43. Specifically, the cleaning water sprayed from the cleaning nozzle 45 onto the object to be cleaned D accumulates at the bottom 50A of the cleaning tank 50 along with the residue washed away from the object to be cleaned D. The cleaning water accumulated at the bottom 50A of the cleaning tank 50 flows into the recess 56. However, as mentioned above, the punching filter 57 has greater resistance to the passage of cleaning water than the grid filter 59 and the mesh filter 58, so most of the cleaning water flows into the upper contamination retention space S1 inside the grid filter 59.

[0060] Since the upper opening 59C of the grid filter 59 is open in the middle contamination retention space S3, the washing water that flows into the upper contamination retention space S1 flows into the middle contamination retention space S3 via the upper opening 59C. At this time, any large residues that could not pass through each opening 59D of the upper opening 59C are captured in the upper contamination retention space S1.

[0061] During the cleaning process, the cleaning pump 43 is driven and the drainage pump 47 is stopped. As a result, the cleaning water that flows into the intermediate contamination retention space S3 passes through the mesh member 58C provided on the side surface 58A of the mesh filter 58, and flows into the inflow space S2 of the cleaning path 44 via space S5 and the inlet 44A. After that, the cleaning water passes through each part of the cleaning path 44, reaches the cleaning nozzle 45, and is sprayed again toward the object to be cleaned D.

[0062] Here, as the cleaning water passes through the mesh member 58C, any residue or other contaminants contained in the cleaning water are captured by the mesh member 58C. As a result, while the cleaning pump 43 is operating at a high rotational speed, the amount of residue and other contaminants adhering to the mesh member 58C continues to increase, and the side surface 58A of the mesh filter 58 gradually becomes blocked. Conventionally, in order to prevent such blocking of the mesh filter 58, the height dimension of the mesh filter 58 was increased and the area of ​​the side surface 58A was increased, which made it difficult to secure the volume of the cleaning tank 50.

[0063] In contrast, in this embodiment, the operation control unit 94 temporarily reduces the rotation speed of the cleaning pump 43 during the cleaning process in order to suppress blockage of the mesh filter 58. This temporarily weakens the flow of cleaning water passing from the middle contamination retention space S3 to space S5 along the side surface 58A of the mesh filter 58, allowing residues and other debris attached to the side surface 58A of the mesh filter 58 to settle due to gravity. Furthermore, since the middle contamination retention space S3 is connected to the lower contamination retention space S4 below via the lower opening 64 of the first partition member 60, the residues and other debris that have settled from the side surface 58A can be retained in the lower contamination retention space S4.

[0064] In this embodiment, the lower opening 64 is composed of a plurality of openings 65 that radiate outwards from the outer edge of the first partition 61 towards the inner edge of the second partition 62. Furthermore, in a plan view, at least a portion of each opening 65 is configured not to overlap with the first partition 61. As a result, residue and other debris that settle in the middle contamination retention space S3 can easily pass through each opening 65 and flow into the lower contamination retention space S4 below. Moreover, each opening 65 of the lower opening 64 is inclined downward from the outer edge of the first partition 61 towards the inner edge of the second partition 62. As a result, compared to, for example, a case where each opening of the lower opening 64 is provided horizontally, when the operation control unit 94 reduces the rotation speed of the cleaning pump 43, residue and other debris that have flowed into the lower contamination retention space S4 are less likely to flow back into the middle contamination retention space S3. In addition, the middle contamination retention space S3, which retains contamination, can be secured in a larger height direction.

[0065] Furthermore, since the lower contamination retention space S4 is connected to the drainage path 46, when the operation control unit 94 drives the drainage pump 47, the residue and other substances retained in the lower contamination retention space S4 can be discharged into the drainage pipe or the like. As a result, residue and other substances are less likely to accumulate in the lower contamination retention space S4, and backflow of residue and other substances from the lower contamination retention space S4 to the middle contamination retention space S3 can be suppressed.

[0066] [1-2-3. Details of the operation of the washing pump in the washing process] Next, the operation of the cleaning pump 43 in the cleaning process will be described in detail. Figure 7 is a diagram showing the change in rotational speed of the cleaning pump 43 in the cleaning process. In the example of Figure 7, the change in rotational speed of the cleaning pump 43 in a cleaning process that started at time t0 and ended at time t6 is shown. As shown in Figure 7, the operation control unit 94 controls the rotational speed of the cleaning pump 43 to rotational speed N0 after the cleaning pump 43 starts operating. In this embodiment, the operation control unit 94 controls the rotational speed of the cleaning pump 43 to rotational speed N0 for most of the time in the cleaning process.

[0067] The operation control unit 94, from time t0 when the cleaning process starts until time t6 when the cleaning process ends, temporarily reduces the rotation speed of the cleaning pump 43 by a decrease amount ΔN from rotation speed N0, and returns it to rotation speed N0 after the decrease time Δt has elapsed. In this embodiment, the operation control unit 94 performs the operation of temporarily reducing the rotation speed of the cleaning pump 43 by a decrease amount ΔN from rotation speed N0 and returning it to rotation speed N0 five or more times between time t0 and time t6. Specifically, the operation control unit 94 temporarily reduces the rotation speed of the cleaning pump 43 at least at times t1, t2, t3, t4, and t5 between time t0 and time t6. As a result, residue and other debris adhering to the side surface 58A of the mesh filter 58 can be settled multiple times during a single cleaning process, making it easier to suppress blockage of the mesh filter 58.

[0068] As shown in Figure 7, at time t1, the operation control unit 94 temporarily reduces the rotational speed of the cleaning pump 43 by a reduction amount ΔN1 from rotational speed N0 and stops the operation of the cleaning pump 43. That is, the reduction amount ΔN1 is equal to the rotational speed N0. The operation control unit 94 then restarts the operation of the cleaning pump 43 and returns the rotational speed to rotational speed N0 at a time when the reduction time Δt1 has elapsed from time t1. The reduction time Δt1, that is, the time during which the operation control unit 94 stops the cleaning pump 43, is set to a predetermined time. The predetermined time is, for example, 5 seconds.

[0069] The operation control unit 94 temporarily reduces the rotational speed of the cleaning pump 43 from rotational speed N0 by amounts ΔN2, ΔN3, ΔN4, and ΔN5, respectively, at times t2, t3, t4, and t5, and controls it to a rotational speed less than N0 and greater than or equal to a predetermined rotational speed Ns. The predetermined rotational speed Ns is, for example, a rotational speed at which the flow of cleaning water in the cleaning path 44 is slightly maintained when the rotational speed of the cleaning pump 43 is at the predetermined rotational speed Ns. The operation control unit 94 then returns the rotational speed of the cleaning pump 43 to rotational speed N0 at times t2, t3, t4, and t5 after the reduction time Δt2, Δt3, Δt4, and Δt5 has elapsed. The reduction time Δt2, Δt3, Δt4, and Δt5 may be greater than or equal to the predetermined time.

[0070] As described above, in this embodiment, if the operation control unit 94 reduces the rotational speed of the cleaning pump 43 and temporarily stops it, it restores the rotational speed of the cleaning pump 43 within a predetermined time after stopping the cleaning pump 43. Furthermore, if the operation control unit 94 does not restore the rotational speed of the cleaning pump 43 to rotational speed N0 within a predetermined time after reducing the rotational speed of the cleaning pump 43, it does not reduce the rotational speed of the cleaning pump 43 to below a predetermined rotational speed Ns. This prevents the temperature of the cleaning water, etc., around the heater 48 from rising excessively, even if the heater 48 provided inside the casing 43A of the cleaning pump 43 is generating heat.

[0071] Furthermore, in this embodiment, the cleaning nozzle 45 is equipped with a center nozzle 45A that incorporates a water distribution mechanism. Therefore, each time the operation control unit 94 temporarily reduces the rotation speed of the cleaning pump 43 and returns it to its original rotation speed, the direction of the cleaning water sprayed from the center nozzle 45A can be switched.

[0072] [1-3. Effects, etc.] As described above, in this embodiment, the dishwasher 1 comprises a washing tank 50 for containing the items to be washed D, a washing nozzle 45 for spraying washing water into the washing tank 50, a grid filter 59 provided at the bottom 50A of the washing tank 50, and a mesh filter 58 formed in a cylindrical shape with a side surface 58A along the vertical direction, partitioning the middle contamination retention space S3 on its inside. The grid filter 59 partitions the middle contamination retention space S3 from above and has an upper opening 59C that opens into the middle contamination retention space S3. Outside the middle contamination retention space S3, a space S5 is formed that communicates with the washing nozzle 45 via a washing path 44. Below the middle contamination retention space S3, a lower contamination retention space S4 is formed, and the middle contamination retention space S3 and the lower contamination retention space S4 communicate with each other via a lower opening 64. This allows residues adhering to the mesh filter 58 to settle in the middle contamination retention space S3 and collect in the lower contamination retention space S4 when the spray of cleaning water from the cleaning nozzle 45 is weakened, making it less likely for the mesh filter 58 to become clogged. As a result, the height of the mesh filter 58 can be reduced, making it easier to increase the volume of the cleaning tank 50. In addition, dirt is less likely to accumulate on the mesh filter 58, eliminating the need for filter maintenance for extended periods after operation.

[0073] As in this embodiment, in the dishwasher 1, the inlet 44A of the washing path 44 may be configured to be located above the lower opening 64 and below the upper opening 59C in the space S5. This prevents the water flow passing through each opening 59D of the upper opening 59C from being biased towards the side closer to the inlet 44A, reduces the adhesion of residue to the mesh member 58C, and promotes the collection of residue into the lower contamination retention space S4.

[0074] As in this embodiment, in the dishwasher 1, the middle contamination retention space S3 and the lower contamination retention space S4 are separated vertically by a first partition 61 and a second partition 62 that surrounds the first partition 61 in a plan view and is located below the first partition 61. The lower opening 64 has a plurality of openings 65 that radiate outwards from the outer edge of the first partition 61 toward the inner edge of the second partition 62 and are inclined downwards, and at least a portion of each opening 65 may be configured not to overlap with the first partition 61 in a plan view. As a result, residues that settle from the mesh filter 58 tend to accumulate in the lower contamination retention space S4, and are less likely to flow back from the lower contamination retention space S4 to the middle contamination retention space S3, thus preventing the mesh filter 58 from becoming clogged. Therefore, the height of the mesh filter 58 can be reduced, making it easier to increase the volume of the washing tank 50.

[0075] As in this embodiment, the washing tank 50 may be configured such that a punching filter 57 is provided at the bottom 50A of the washing tank 50 and partitions the space S5 from above, and cylindrical peripheral wall portions 55D, 66A, and 68 surround the mesh filter 58 in a plan view and partition the space S5 from the outside, and the upper edges of the peripheral wall portions 55D, 66A, and 68 are spaced 10 mm or more below the punching filter 57 in an area of ​​more than half the circumference of the peripheral wall portions 55D, 66A, and 68. This prevents the water flow passing through the perforated filter 57 from being biased towards the side closer to the mesh filter 58, and prevents residue from sticking to the perforated filter 57.

[0076] As in this embodiment, the dishwasher 1 may be configured such that the lower contamination retention space S4 is connected to the drainage path 46. This allows the residue and other materials collected in the lower contamination retention space S4 to be discharged, and makes it less likely for the residue and other materials to flow back into the middle contamination retention space S3. As a result, the height dimension of the mesh filter 58 can be reduced, and the volume of the washing tank 50 can be increased more easily.

[0077] In this embodiment, the control method for the dishwasher 1 comprises a washing tank 50 for containing the items to be washed D, a washing nozzle 45 for spraying washing water into the washing tank 50, a grid filter 59 provided at the bottom 50A of the washing tank 50, and a mesh filter 58 formed in a cylindrical shape with a side surface 58A along the vertical direction, partitioning the middle contamination retention space S3 on its inside. The grid filter 59 partitions the middle contamination retention space S3 from above and has an upper opening 59C that opens into the middle contamination retention space S3. Outside the space S3, a space S5 is formed that communicates with the washing nozzle 45 via a washing path 44. Below the middle contamination retention space S3, a lower contamination retention space S4 is formed. The middle contamination retention space S3 and the lower contamination retention space S4 communicate with each other via a lower opening 64. The dishwasher 1 is equipped with a washing pump 43 that transports the washing water from space S5 to the washing nozzle 45 via the washing path 44. The control unit 90 installed in the dishwasher 1 temporarily reduces the rotation speed of the washing pump 43 during the washing process to wash the items to be washed D. As a result, during the cleaning process, residues and other debris adhering to the mesh filter 58 in the middle contamination retention space S3 can settle and be collected in the lower contamination retention space S4, making it less likely for the mesh filter 58 to become clogged. Therefore, the height dimension of the mesh filter 58 can be reduced, making it easier to increase the volume of the cleaning tank 50.

[0078] As in this embodiment, the control method for the dishwasher 1 may be configured such that, during the washing process, the control unit 90 of the dishwasher 1, which is equipped with a heater 48 inside the casing 43A of the washing pump 43, stops the washing pump 43 for a predetermined period of time or less, or temporarily reduces the rotational speed of the washing pump 43 to a rotational speed of a predetermined number of rotational speeds Ns or higher. This allows for the collection of residues and other debris in the lower contamination retention space S4 while suppressing excessive temperature rise within the casing 43A. Therefore, it is possible to increase the volume of the cleaning tank 50 while ensuring the reliability of the cleaning pump 43's operation.

[0079] As in this embodiment, the control method for the dishwasher 1 may be configured such that the control unit 90 temporarily reduces the rotation speed of the washing pump 43 five or more times during a single washing cycle. This prevents the mesh filter 58 from becoming clogged during the cleaning process. As a result, the height of the mesh filter 58 can be reduced, making it easier to increase the volume of the cleaning tank 50.

[0080] (Embodiment 2) The dishwasher 1 according to Embodiment 2 will be described below. Note that the following will describe the differences from Embodiment 1, and explanations of matters similar to those in Embodiment 1 may be omitted.

[0081] The dishwasher 1 according to Embodiment 2 has the same configuration as the dishwasher 1 according to Embodiment 1, with only its operation differing. The operation of the dishwasher 1 according to Embodiment 2 will be described below.

[0082] Figure 8 shows the change in the rotational speed of the cleaning pump 43 after the operation control unit 94 in Embodiment 2 temporarily reduces the rotational speed of the cleaning pump 43 during the cleaning process, and then returns the rotational speed to its original value. In this embodiment, the operation control unit 94 temporarily reduces the rotational speed of the cleaning pump 43 from the rotational speed N0 during the cleaning process, and then increases the rotational speed of the cleaning pump 43 in two stages, returning it to rotational speed N0.

[0083] In the example shown in Figure 8, the control unit 94 begins to reduce the rotational speed of the cleaning pump 43 from rotational speed N0 to 500 rpm at time t7. The control unit 94 maintains the rotational speed of the cleaning pump 43 at 500 rpm for a predetermined time Δt71. Next, the control unit 94 increases the rotational speed of the cleaning pump 43 from 500 rpm to 1000 rpm and maintains the rotational speed of the cleaning pump 43 at 1000 rpm for a predetermined time Δt72. After that, the control unit 94 increases the rotational speed of the cleaning pump 43 back to rotational speed N0. Furthermore, it is preferable to set the predetermined time △t71 to be longer than the predetermined time △t72. This makes it possible to reduce the noise level while shortening the time required for re-acceleration. On the other hand, the predetermined time △t71 can also be set to be shorter than the predetermined time △t72. This can reduce the noise level.

[0084] Thus, in this embodiment, the control method for the dishwasher 1 involves the control unit 90 temporarily reducing the rotation speed of the washing pump 43 during the washing process, and then increasing the rotation speed of the washing pump 43 in two stages to return it to its original speed. This makes it easier to reduce the noise level caused by the operation of the cleaning pump 43 while also shortening the time required for the rotational speed of the cleaning pump 43 to increase.

[0085] (Other embodiments) As described above, Embodiments 1 and 2 have been presented as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can be applied to embodiments that have been modified, replaced, added, or omitted. Furthermore, it is possible to combine the components described in Embodiments 1 and 2 to create new embodiments. Therefore, other embodiments are illustrated below.

[0086] In Embodiments 1 and 2, a pull-out type built-in dishwasher was described as an example of the dishwasher 1, but this is merely an example. The dishwasher 1 may be a front-opening type or a countertop type. However, when the dishwasher 1 is a pull-out type, the space below the washing tub 50 is small, so by applying this disclosure and reducing the height dimension of the mesh filter 58, it is easier to effectively secure the volume of the washing tub 50.

[0087] In the above embodiment, the operation control unit 94 was described as performing the operation of temporarily reducing the rotational speed of the cleaning pump 43 and then returning it to its original rotational speed five or more times during a single cleaning process, but this is just an example. The operation control unit 94 only needs to perform the above operation once or more times during a cleaning process. Furthermore, the operation control unit 94 may arbitrarily combine and execute the operation of temporarily stopping the cleaning pump 43 after reducing its rotational speed from rotational speed N0, and the operation of temporarily maintaining the rotational speed of the cleaning pump 43 at a rotational speed below rotational speed N0, during a single cleaning process. In addition, the operation control unit 94 may arbitrarily set the reduction amount ΔN and the reduction time Δt for the operation of temporarily reducing the rotational speed of the cleaning pump 43 and then returning it to its original rotational speed.

[0088] In the above embodiment, it was explained that the multiple openings 65 of the lower opening 64 are formed over substantially the entire circumference of the outer edge of the first partition 61, but this is just one example. The multiple openings 65 may be provided only on a portion of the outer edge of the first partition 61. For example, the lower opening 64 may have only three openings 65 provided on the outer edge of the first partition 61 at positions offset from each other by approximately 120° in the circumferential direction. Also, in the above embodiment, it was explained that the first partition 61 is located above the outer second partition 62, and each opening 65 of the lower opening 64 is inclined downward from the outer edge of the first partition 61 toward the inner edge of the second partition 62, but this is just one example. For example, the outer edge of the first partition 61 and the inner edge of the second partition 62 may be formed at approximately the same height, and each opening 65 of the lower opening 64 may be formed approximately horizontally. Alternatively, for example, the outer edge of the first partition 61 may be formed lower than the inner edge of the second partition 62, and each opening 65 of the lower opening 64 may be inclined upward from the outer edge of the first partition 61 toward the inner edge of the second partition 62.

[0089] In the above embodiment, the control unit 90 was described as including a processor 91 and a storage medium 92, but this is just one example. The control unit 90 may, for example, use wired logic that cannot be rewritten. Using wired logic in the control unit 90 is effective in improving processing speed. Examples of wired logic include ASICs (Application Specific Integrated Circuits). The control unit 90 may also be implemented by combining a processor and wired logic. Implementing the control unit 90 by combining a processor and wired logic can improve processing speed while increasing the freedom of software design. Furthermore, the control unit 90 and a circuit having a different function from the control unit 90 may be configured with a single semiconductor element. Examples of circuits having a different function include A / D-D / A conversion circuits. The control unit 90 may also be configured with a single semiconductor element or with multiple semiconductor elements. When configured with multiple semiconductor elements, various controls may be implemented with different semiconductor elements. Moreover, the control unit 90 may be configured with a configuration including semiconductor elements and passive components such as resistors or capacitors.

[0090] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents.

[0091] (Note) Based on the above description of embodiments, the following technologies are disclosed. (Technical 1) A dishwasher comprising: a washing tank for containing items to be washed; an injection unit for injecting washing water into the washing tank; a first filter provided at the bottom of the washing tank; and a second filter formed in a cylindrical shape with sides aligned in the vertical direction, partitioning a first contamination retention space on its inside, wherein the first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space; a first space is formed outside the first contamination retention space that communicates with the injection unit via a washing path; a second contamination retention space is formed below the first contamination retention space; and the first contamination retention space and the second contamination retention space communicate with each other via the second opening. This allows residues adhering to the second filter in the first contamination retention space to settle and collect in the second contamination retention space when the spray of cleaning water from the spray nozzle is weakened, making it less likely for the second filter to become clogged. As a result, the height of the second filter can be reduced while suppressing contamination of the cleaning water and improving ease of maintenance.

[0092] (Technical 2) The dishwasher according to Technical 1, wherein the inlet of the washing path is located above the second opening and below the first opening in the first space. This prevents the water flow passing through the first opening from being biased towards the side closer to the inlet of the washing path, reduces the adhesion of residue to the side of the second filter, and promotes the collection of residue into the second contamination retention space.

[0093] (Technical 3) The dishwasher according to Technical 1 or 2, wherein the first contamination-retaining space and the second contamination-retaining space are separated vertically by a first partition and a second partition that surrounds the first partition in a plan view and is provided below the first partition, and the second opening has a plurality of openings that radiate outward from the outer edge of the first partition towards the inner edge of the second partition and are inclined downward, and at least a portion of each of the openings does not overlap with the first partition in a plan view. As a result, residue and other particles that settle from the second filter tend to accumulate in the second contamination retention space, and it becomes less likely for them to flow back from the second contamination retention space to the first contamination retention space, thus reducing the likelihood of the second filter becoming clogged. Therefore, the height of the second filter can be reduced, making it easier to increase the volume of the washing tank.

[0094] (Technical 4) A dishwasher according to any one of Technical 1 to 3, comprising: a third filter provided at the bottom of the washing tank and partitioning the first space from above; and a cylindrical peripheral wall portion surrounding the second filter in a plan view and partitioning the first space from the outside, wherein the upper edge of the peripheral wall portion is spaced at least 10 mm below the third filter over a range of half the circumference or more of the peripheral wall portion. This prevents the water flow passing through the third filter from being biased towards the side closer to the second filter, thus preventing residue from sticking to the third filter.

[0095] (Technical 5) The dishwasher according to any one of Technical 1 to 4, wherein the second contamination retention space is connected to a drainage path. This allows the residue and other materials collected in the second contamination retention space to be discharged, making it less likely for the residue and other materials to flow back into the first contamination retention space. As a result, the height of the second filter can be reduced, making it easier to increase the volume of the washing tank.

[0096] (Technical 6) A dishwasher control method comprising: a washing tank for containing objects to be washed; an injection unit for injecting washing water into the washing tank; a first filter provided at the bottom of the washing tank; and a second filter formed in a cylindrical shape with sides aligned in the vertical direction, partitioning a first contamination retention space on its inside, wherein the first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space; a first space is formed outside the first contamination retention space, communicating with the injection unit via a washing path; a second contamination retention space is formed below the first contamination retention space; the first contamination retention space and the second contamination retention space communicate via the second opening; and a washing pump is provided for transporting washing water from the first space to the injection unit via the washing path, wherein a control unit provided in the dishwasher temporarily reduces the rotation speed of the washing pump during the washing process for washing the objects to be washed. This allows residues and other debris adhering to the second filter in the first contamination retention space to settle and collect in the second contamination retention space during the cleaning process, making it less likely for the second filter to become clogged. As a result, the height of the second filter can be reduced, making it easier to increase the volume of the cleaning tank.

[0097] (Technical 7) The dishwasher control method according to Technical 6, wherein the dishwasher is equipped with a heater in the casing of the washing pump, and the control unit stops the washing pump for a predetermined period of time or less during the washing process, or temporarily reduces the rotational speed of the washing pump to a rotational speed equal to or greater than a predetermined rotational speed. This allows for the collection of residues and other contaminants in the second contamination retention space while suppressing excessive temperature rises within the casing. As a result, it becomes easier to increase the volume of the cleaning tank while ensuring the reliability of the cleaning pump's operation.

[0098] (Technical 8) A dishwasher control method according to Technical 6 or 7, wherein the control unit temporarily reduces the rotation speed of the washing pump five or more times during a single washing cycle. This prevents the second filter from becoming clogged during the cleaning process. As a result, the height of the second filter can be reduced, making it easier to increase the volume of the cleaning tank.

[0099] (Technical 9) A dishwasher control method according to any one of Technical 6 to 8, wherein the control unit temporarily reduces the rotation speed of the washing pump during the washing process, and then increases the rotation speed of the washing pump in two stages to return it to its original speed. This makes it easier to reduce the noise level caused by the operation of the cleaning pump while also shortening the time required for the cleaning pump's rotation speed to increase. [Industrial applicability]

[0100] This disclosure is applicable to dishwashers. Specifically, it is applicable to any dishwasher, such as drawer-type, front-opening built-in dishwashers, or countertop dishwashers. [Explanation of symbols]

[0101] 1 Dishwasher 10 cabinets 11 Door Body 13. The second rail 15 Lid 16 Lid side contact part 17 Parallel link mechanism 30 Washing baskets 41 First Rail 43 Washing pump 43A Casing 44 Cleaning Route 44A Inlet 45. Cleaning nozzle (spray part) 45A Center Nozzle 46 Drainage routes 47 Drainage pump 48 Heater 50 Washing Tanks 50A bottom 51 Aperture 52 Side members 53 Bottom member 54 Bottom part 54A Nozzle shaft 54B Bottom opening 55 Concave member 55A Edge 55B Connection Port 55C connector 55D Peripheral wall part 55E Connection 55F front 55G Rear 55H Drainage introduction part 55J Projection 56 Recess 57. Punching filter (third filter) 57A Filter insertion opening 58-mesh filter (second filter) 58A side 58B Frame 58C Mesh Member 58D Edge 58E protrusion 59. Grid filter (first filter) 59A side 59B Bottom 59C Upper opening (1st opening) 59D aperture 59E Edge 59F protrusion 59G Snack 60 First partition member 61 First partition section 62 Second partition section 63 Connection part 64 Lower opening (second opening) 65 Aperture 66 Third partition section 66A Peripheral wall section 66B Top part 67 Second partition member 67A protrusion 68 Peripheral wall section 69 Top part 90 Control Unit 91 processors 92 Storage medium 93 Control Program 94 Operation Control Unit D Item to be cleaned G Gap S1 Upper contamination retention space S2 Inflow space S3 Intermediate contamination containment space (First contamination containment space) S4 Lower contamination containment space (Second contamination containment space) S5 space (first space)

Claims

1. A washing tank for containing the items to be washed, The cleaning tank includes an injection unit that sprays cleaning water into the interior of the cleaning tank, A first filter provided at the bottom of the washing tank, It is formed in a cylindrical shape with sides aligned in the vertical direction, and comprises a second filter that partitions the first contamination retention space on the inside, The first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space. Outside the first contamination retention space, a first space is formed that communicates with the spray section via a cleaning path. Below the first contamination retention space, a second contamination retention space is formed. The first contamination-retaining space and the second contamination-retaining space are in communication through the second opening. dishwasher.

2. The inlet of the cleaning path is located in the first space above the second opening and below the first opening. The dishwasher according to claim 1.

3. The first contamination-retaining space and the second contamination-retaining space are separated vertically by a first partition and a second partition that surrounds the first partition in a plan view and is located below the first partition. The second opening has a plurality of openings that radiate outward from the outer edge of the first partition towards the inner edge of the second partition and are inclined downward. At least a portion of each of the aforementioned openings does not overlap with the first partition in a plan view. The dishwasher according to claim 1.

4. A third filter is provided at the bottom of the washing tank and partitions the first space from above, It comprises a cylindrical peripheral wall portion that surrounds the second filter in a plan view and partitions the first space from the outside, In the area of ​​more than half the circumference of the peripheral wall portion, the upper edge of the peripheral wall portion is spaced at least 10 mm below the third filter. The dishwasher according to claim 1.

5. The aforementioned second contamination retention space is connected to the drainage route. The dishwasher according to claim 1.

6. A washing tank for containing the items to be washed, The cleaning tank includes an injection unit that sprays cleaning water into the interior of the cleaning tank, A first filter provided at the bottom of the washing tank, It is formed in a cylindrical shape with sides aligned in the vertical direction, and comprises a second filter that partitions the first contamination retention space on the inside, The first filter partitions the first contamination retention space from above and has a first opening that opens into the first contamination retention space. Outside the first contamination retention space, a first space is formed that communicates with the spray section via a cleaning path. Below the first contamination retention space, a second contamination retention space is formed. The first contamination-retaining space and the second contamination-retaining space are in communication through the second opening. A control unit provided in the dishwasher is equipped with a washing pump that transports the washing water from the first space to the spray unit via the washing path, During the cleaning process for cleaning the object to be cleaned, the rotation speed of the cleaning pump is temporarily reduced. How to control a dishwasher.

7. The dishwasher is equipped with a heater inside the casing of the washing pump. The control unit may, during the cleaning process, stop the cleaning pump for a predetermined period of time or temporarily reduce the rotation speed of the cleaning pump to a rotation speed equal to or greater than a predetermined rotation speed. A method for controlling a dishwasher according to claim 6.

8. The control unit temporarily reduces the rotation speed of the cleaning pump five or more times during a single cleaning process. A method for controlling a dishwasher according to claim 6.

9. The control unit temporarily reduces the rotation speed of the cleaning pump during the cleaning process, and then increases the rotation speed of the cleaning pump in two stages to return it to its original speed. A method for controlling a dishwasher according to claim 6.

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