A control method of a washing machine

Abstract

The present application belongs to the technical field of washing machines, and discloses a control method of a washing machine, which comprises an inner drum for independently containing water, a water drainage device for blocking the inner drum or opening the inner drum to drain water, and a water collecting device arranged at the bottom of the inner drum, wherein a water level detection device is arranged in the water collecting device; the control method comprises the following steps: S1, the washing machine receives a water drainage instruction; S2, the water drainage device performs a pre-drainage process of opening and closing; S3, the water drainage device is opened again and performs water drainage; and S4, the water drainage of the water drainage device is controlled according to the detection result of the water level detection device. In the water drainage stage, the water drainage device first performs the pre-drainage process of opening and closing, and the closing of the water drainage device in the pre-drainage process is not controlled by the detection result of the water level detection device, so that the phenomenon of overflow of the water collecting device caused by the high water level of the inner drum, the fast water drainage rate and the untimely feedback of the detection result is avoided.

Description

Technical Field

[0001] This invention belongs to the field of washing machine technology, specifically, it relates to a control method for a washing machine. Background Technology

[0002] Traditional washing machines mostly consist of an inner tub and an outer tub that are connected to each other. When the washing machine is working, the outer tub holds the washing water, and the inner tub holds the clothes to be washed. The washing water can exist between the inner and outer tubs. However, as the washing machine runs for a long time, dirt and lint in the washing water can easily get stuck in the space between the inner and outer tubs and are difficult to clean. This can lead to bacteria and odors after years of use, affecting the hygiene of the washed clothes and endangering the user's health.

[0003] To solve this problem, such as Figure 1 As shown, the prior art proposes a washing machine without a drain hole on the inner tub 1, allowing the inner tub 1 to independently hold the washing water during the washing process. Simultaneously, to expand the capacity of the inner tub 1, the outer tub can be eliminated, and a water collection device 2, whose upper edge is lower than the opening of the inner tub 1, can be used instead. During the washing / rinsing process, all the washing / rinsing water is stored in the inner tub 1. When the drain valve is opened to drain water, unlike traditional washing machines where the water level drops simultaneously in both the inner and outer tubs, in the above scheme, the water in the inner tub 1 first passes through the water collection device 2 before being discharged from the washing machine. However, at this time, the amount of water in the inner tub 1 is relatively large, and the water level is high, causing the drainage rate of the inner tub 1 to be higher than the drainage rate of the water collection device 2. If the drain valve remains open, the water level in the water collection device 2 will continue to rise. When the water level rises to the upper edge of the water collection device 2, it will overflow, affecting normal use by the user.

[0004] For washing machines with the above-mentioned structure, how to control the drainage process and thus control the water level of the water collection device 2 to prevent overflow of the water collection device 2 has become an urgent problem to be solved.

[0005] In view of this, the present invention is hereby proposed. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a control method for a washing machine. In the drainage stage, the washing machine controls the drainage device to first perform a pre-drainage process of opening and closing, so as to avoid the phenomenon of water overflow in the water collection device caused by the high water level in the inner tub, the fast drainage rate, and the untimely feedback of the detection results of the water level detection device.

[0007] To solve the above-mentioned technical problems, the basic concept of the technical solution adopted by the present invention is as follows:

[0008] A method for controlling a washing machine, the washing machine including an inner tub that holds water independently, a drain device for sealing or opening the inner tub to drain water, and a water collection device disposed at the bottom of the inner tub, wherein a water level detection device is disposed in the water collection device.

[0009] The control method includes the following steps:

[0010] S1. The washing machine receives a drain command;

[0011] S2. The drainage device performs a pre-drainage process of opening and closing;

[0012] S3. The drainage device is restarted and drainage is carried out.

[0013] S4. Control the drainage device to drain water based on the detection results of the water level detection device.

[0014] Furthermore, in step S2, after the drainage device is fully opened, the drainage device performs a closing operation to stop drainage.

[0015] Furthermore, in step S3, the drainage device is controlled to restart based on the water level H detected by the water level detection device.

[0016] Further, step S3 includes: when the water level H detected by the water level detection device drops to the first preset water level H1, controlling the drainage device to start again to drain water.

[0017] Furthermore, in step S4, when the water level H detected by the water level detection device rises to the second preset water level H2, the drainage device is controlled to close and stop drainage, returning to step S3; wherein, H2>H1;

[0018] Preferably, the difference between the second preset water level H2 and the first preset water level H1 is greater than half the height of the water collection device.

[0019] Furthermore, the water level detection device includes a reference probe and a first probe disposed within the water collection device, wherein the first probe is installed higher than the reference probe; when the water level in the water collection device reaches a first preset water level H1, the reference probe and the first probe are connected through the washing water.

[0020] In step S3, when the washing machine receives a signal that the reference probe and the first probe are disconnected, it controls the drainage device to start draining.

[0021] Furthermore, the water level detection device also includes a second probe disposed within the water collection device, the second probe being installed higher than the first probe; when the water level in the water collection device reaches a second preset water level H2, the reference probe and the second probe are connected through the washing water;

[0022] In step S4, when the washing machine receives a signal that the reference probe and the second probe are turned on, it controls the drainage device to close and stop draining.

[0023] Preferably, the first probe is disposed in the lower region of the side wall of the water collection device, and the second probe is disposed in the upper region of the side wall of the water collection device.

[0024] Furthermore, if the washing machine does not receive a signal indicating that the reference probe and the second probe are disconnected within a first preset time period after the drainage device is turned off, the drainage process will be paused and the washing machine will issue an alarm message.

[0025] Furthermore, between steps S3 and S4, step S5 is also included: if the water level detection device detects that all the water in the water collection device has been discharged, the drainage process ends and the inner tub is controlled to rotate for dehydration; otherwise, step S4 is executed.

[0026] Furthermore, the water level detection device also includes a third probe, and both the reference probe and the third probe are disposed on the bottom wall of the water collection device; when there is water in the water collection device, the third probe and the reference probe are connected through the washing water;

[0027] In step S5, if the washing machine receives a signal that the reference probe and the third probe have disconnected for a second preset time, the drainage process ends and the inner tub is controlled to rotate for spin-drying.

[0028] By adopting the above technical solution, the present invention has the following beneficial effects compared with the prior art.

[0029] In the draining stage of the washing machine of the present invention, the draining device first performs a pre-draining process of opening and closing. During the pre-draining process, the closing of the draining device is not controlled by the detection result of the water level detection device, which avoids the overflow of the water collection device caused by the high water level in the inner tub, the fast draining rate, and the untimely feedback of the detection result.

[0030] In the pre-draining process, the washing machine of the present invention maintains the water level in the water collection device below a certain level by repeatedly opening and closing the drain device during the drainage process, thus preventing overflow. The timing of opening and closing the drain device is controlled by preset first preset water level H1 and second preset water level H2, respectively. Furthermore, maximizing the difference between the first preset water level H1 and the second preset water level H2 reduces the frequency of drain device operation.

[0031] The washing machine of this invention uses a first probe and a second probe, installed at different heights, to conduct water level detection through a reference probe. Compared to traditional water level sensors, this method generates a feedback signal as soon as the water level reaches the corresponding height, resulting in more timely and accurate water level detection. While ensuring that the water collection device does not overflow, it maximizes the difference between the first preset water level H1 and the second preset water level H2, further reducing the number of times the drainage device operates, avoiding frequent operation that could shorten its lifespan, and also reducing drainage time.

[0032] The washing machine of the present invention also uses a third probe to cooperate with a reference probe to detect whether there is water in the water collection device. This allows for timely and accurate determination of whether the water in the water collection device has been drained, thereby controlling the washing machine to enter the spin-drying stage for spin-drying.

[0033] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings. Attached Figure Description

[0034] The accompanying drawings, as part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention, but do not constitute an undue limitation of the invention. Obviously, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without creative effort. In the drawings:

[0035] Figure 1 This is a structural diagram of a washing machine without an outer tub in the existing technology;

[0036] Figure 2 This is a schematic diagram of the structure of the washing machine in an embodiment of the present invention;

[0037] Figure 3 This is a flowchart of the control method for a washing machine in an embodiment of the present invention;

[0038] Figure 4 This is a flowchart of another control method for a washing machine in an embodiment of the present invention.

[0039] In the diagram: 1. Inner tub; 2. Water collection device; 10. Inner tub; 11. Drain outlet; 20. Water collection device; 30. Reference probe; 31. First probe; 32. Second probe; 33. Third probe; 40. Drainage pipe.

[0040] It should be noted that these accompanying drawings and textual descriptions are not intended to limit the scope of the invention in any way, but rather to illustrate the concept of the invention to those skilled in the art by referring to specific embodiments. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the accompanying drawings. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0042] In the description of this invention, it should be noted that the terms "upper", "lower", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] An embodiment of the present invention provides a control method for a washing machine.

[0045] like Figure 2 As shown, the washing machine in this embodiment includes an inner tub 10 that holds water independently, a drainage device (not shown in the figure) that seals or opens the inner tub 10 to drain water, and a water collection device 20 disposed at the bottom of the inner tub 10, wherein a water level detection device is disposed inside the water collection device 20.

[0046] In this embodiment, the inner tub 10 has no dewatering holes, at least in the area below the highest water level of the washing machine. The drainage device seals the inner tub 10 during washing / rinsing, allowing it to hold water independently, with no water between the inner tub 10 and the water collection device 20. During drainage, the drainage device opens the drain outlet 11 on the inner tub 10, draining water into the water collection device 20, which then discharges the water from the washing machine through the drain pipe 40 connected to the water collection device 20. The drainage device can be a drain valve.

[0047] like Figure 3 As shown, the control method includes the following steps:

[0048] S1. The washing machine receives a drain command;

[0049] S2. The drainage device performs a pre-drainage process of opening and closing;

[0050] S3. The drainage device is restarted and drainage is carried out.

[0051] S4. Control the drainage device to drain water based on the detection results of the water level detection device.

[0052] Furthermore, in step S2, after the drainage device is fully opened, the drainage device performs a closing operation to stop drainage.

[0053] In this embodiment, the upper edge of the water collecting device 20 is lower than the opening of the inner tub 10. If the drainage device remains open during the drainage phase, the water level in the water collecting device 20 may continuously rise and overflow because the rate at which the inner tub 10 drains water into the water collecting device 20 is higher than the rate at which the water collecting device 20 drains water through the drainage pipe 40. Therefore, it is necessary to control the drainage rate of the inner tub 10 so that the water level in the water collecting device 20 does not exceed the highest water level corresponding to the upper edge during the drainage process. For example, the drainage device can be temporarily shut off when the water level in the water collecting device 20 is high, suspending the drainage from the inner tub 10 to the water collecting device 20 to prevent water from overflowing from the water collecting device 20.

[0054] However, the detection results are fed back from the water level detection device to the washing machine's control system, and the control system then sends a shutdown command to the drain device, which takes a certain amount of time. The drain device also needs time to go from being open to being completely closed. However, in the initial stage of drainage, the water level in the inner tub 10 is high, and the drainage rate is fast. If the drain device is only shut off after the water level detection device detects a high water level in the water collection device 20 during the initial drainage stage, the water level in the water collection device 20 will continue to rise during signal transmission and the shutdown process, potentially causing overflow.

[0055] Therefore, in this embodiment, after receiving the drainage command, the washing machine first performs a pre-drainage process and then immediately shuts down the drainage device after it is fully opened, without controlling the shutdown of the drainage device by the detection result of the water level in the water collection device 20 through the water level detection device.

[0056] During the initial drainage phase, the drainage device is immediately closed after being opened, without pausing in the fully open position. This generally prevents the water level in the collection device 20 from reaching excessively high levels, reducing the risk of overflow during the initial drainage phase. Simultaneously, the pre-drainage process discharges some water, lowering the water level in the inner tank 10. This reduces the drainage rate of the inner tank 10 during subsequent drainage. The drainage can be controlled by the water level detection device, making it easier to ensure that the water level in the collection device 20 remains below the maximum level throughout the entire drainage process, preventing overflow.

[0057] In a further embodiment, in step S3, the drainage device is controlled to restart based on the water level H detected by the water level detection device.

[0058] Specifically, step S3 includes: when the water level H detected by the water level detection device drops to the first preset water level H1, controlling the drainage device to start again to drain water.

[0059] In the above scheme, the drainage device is turned on again when the water level in the water collection device 20 drops to a certain level. After reserving enough water collection space in the water collection device 20, the drainage continues to flow into the water collection device 20. The drainage device can remain open so that the inner tank 10 can continuously drain water for a certain period of time, and the water collection device 20 will not overflow.

[0060] In another embodiment, in step S3, the drainage device can be activated to drain water after a preset waiting time. During the waiting period, the inner tub 10 stops draining water into the water collection device 20, while the water collection device 20 continues to drain water, causing the water level in the water collection device 20 to drop continuously, thus ensuring sufficient water collection space when the drainage device is activated again.

[0061] In a further embodiment, in step S4, when the water level H detected by the water level detection device rises to the second preset water level H2, the drainage device is controlled to close and stop drainage, returning to step S3. Wherein, H2 > H1.

[0062] Preferably, the difference between the second preset water level H2 and the first preset water level H1 is greater than half the height of the water collection device 20. More preferably, the difference between the second preset water level H2 and the first preset water level H1 is close to the height of the water collection device 20.

[0063] In this embodiment, by controlling the repeated opening and closing of the drainage device during the drainage process, the water level in the water collection device 20 is kept below a certain level to avoid overflow. By presetting different first preset water levels H1 and second preset water levels H2 to control the timing of opening and closing of the drainage device, compared with the scheme of controlling the drainage device with the same preset water level, the frequency of drainage device operation can be reduced, thereby reducing the number of times the drainage device operates during the drainage process and extending the service life of the drainage device.

[0064] The difference between the second preset water level H2 and the first preset water level H1 is greater than half the height of the water collection device 20. Increasing the difference between the two preset water levels further reduces the frequency of the drainage device's operation. While ensuring that the water collection device 20 does not overflow, the difference between the second preset water level H2 and the first preset water level H1 is as close as possible to the height of the water collection device 20, maximizing the difference between them and thus further reducing the number of times the drainage device operates.

[0065] In a further embodiment, such as Figure 2As shown, the water level detection device includes a reference probe 30 and a first probe 31 disposed within the water collection device 20, with the first probe 31 installed above the reference probe 30.

[0066] The installation height of the first probe 31 corresponds to the height of the first preset water level H1. When the water level of the water collection device 20 reaches the first preset water level H1, the reference probe 30 and the first probe 31 are connected by the washing water.

[0067] like Figure 4 As shown, in step S3, when the washing machine receives a signal that the reference probe 30 and the first probe 31 are disconnected, it controls the drainage device to start draining.

[0068] Furthermore, the water level detection device also includes a second probe 32 disposed within the water collection device 20, the second probe 32 being installed higher than the first probe 31.

[0069] The installation height of the second probe 32 corresponds to the height of the second preset water level H2. When the water level of the water collection device 20 reaches the second preset water level H2, the reference probe 30 and the second probe 32 are connected through the washing water.

[0070] like Figure 4 As shown, in step S4, when the washing machine receives a signal that the reference probe 30 and the second probe 32 are turned on, it controls the drainage device to close and stop draining.

[0071] Preferably, the first probe 31 is disposed in the lower region of the side wall of the water collection device 20, and the second probe 32 is disposed in the upper region of the side wall of the water collection device 20.

[0072] In the above scheme, compared with traditional water level sensors which have larger errors and may exhibit delayed response, multiple probes are used for water level detection, resulting in more timely signal feedback and significantly reducing water level detection errors. While ensuring that the water collection device 20 does not overflow, the difference between the first preset water level H1 and the second preset water level H2 can be maximized, minimizing the number of times the drainage device needs to operate and shortening the drainage time.

[0073] In this embodiment, both the first probe 31 and the second probe 32 are disposed on the side wall of the water collection device 20, with the first probe 31 disposed in the lower region of the side wall and the second probe 32 disposed in the upper region of the side wall. In the optimal solution, while ensuring that the water collection device 20 does not overflow, the difference in installation height between the first probe 31 and the second probe 32 is close to the height of the water collection device 20, that is, minimizing the distance between the first probe 31 and the bottom wall of the water collection device 20, and minimizing the distance between the second probe 32 and the upper edge of the water collection device 20, thereby maximizing the difference between the first preset water level H1 and the second preset water level H2.

[0074] In a preferred embodiment, after the drainage device is turned off, if the washing machine does not receive a signal indicating that the reference probe 30 and the second probe 32 are disconnected within a first preset time period, the drainage process is paused and the washing machine issues an alarm message.

[0075] In the above scheme, when the washing machine receives a signal indicating that the reference probe 30 and the second probe 32 are conducting, it controls the drain device to close. During the closing process, the water level in the water collection device 20 continues to rise to a certain height and then begins to fall. Under normal circumstances, after the drain device is completely closed, the water level in the water collection device 20 continues to fall. When it drops below the second preset water level H2, the reference probe 30 and the second probe 32 disconnect. The water level in the water collection device 20 continues to fall until it reaches the first preset water level H1, at which point the drain device is then controlled to open.

[0076] However, if the reference probe 30 and the second probe 32 remain conductive for an extended period after the drainage device is closed, it indicates that the water level remains above the second preset water level H2 for a prolonged time. This suggests that the drainage efficiency of the water collection device 20 is very low or even almost nonexistent, possibly due to a blockage in the drain pipe 40. In this case, the washing machine will pause the drainage process and issue an alarm message, prompting the user to manually check the system to prevent prolonged drainage time caused by the water collection device 20 draining too slowly or failing to drain.

[0077] In a further embodiment, such as Figure 4 As shown, step S5 is also included between steps S3 and S4: if the water level detection device detects that all the water in the water collection device 20 has been discharged, the drainage process ends and the inner bucket 10 is controlled to rotate for dehydration; otherwise, step S4 is executed.

[0078] Specifically, the water level detection device further includes a third probe 33, and both the reference probe 30 and the third probe 33 are disposed on the bottom wall of the water collection device 20. When there is water in the water collection device 20, the third probe 33 and the reference probe 30 are connected by washing water.

[0079] In step S5, if the washing machine receives a signal that the reference probe 30 and the third probe 33 have disconnected for a second preset time, the drainage process ends and the inner tub 10 is controlled to rotate for dehydration.

[0080] In the above scheme, the washing machine can also determine whether all the water in the water collection device 20 has been drained through a water level detection device, thereby determining whether to enter the spin-drying stage. This is achieved by setting a third probe 33 to work in conjunction with a reference probe 30. Since both the reference probe 30 and the third probe 33 are located on the bottom wall of the water collection device 20, the connection between the third probe 33 and the reference probe 30 is established once water is present in the water collection device 20. When the connection between the third probe 33 and the reference probe 30 is broken, it indicates that the water in the water collection device 20 has been drained. Therefore, the continuity between the reference probe 30 and the third probe 33 allows for timely and accurate determination of whether all the water in the water collection device 20 has been drained.

[0081] In this embodiment, after the connection between the reference probe 30 and the third probe 33 is broken, a second preset time is waited, such as 10 seconds. If the reference probe 30 and the third probe 33 remain disconnected, it indicates that the water in the water collection device 20 has been completely drained, and the inner tub 10 has not continued to drain water into the water collection device 20, meaning that the water in the inner tub 10 has been drained. At this time, the washing machine ends the drainage process and enters the spin-drying stage, which is performed by controlling the rotation of the inner tub 10.

[0082] Traditional water level sensors suffer from significant and inconsistent errors in detection due to individual variations. This can lead to situations where the water in the collection device 20 has been completely drained, but the sensor still detects water, causing the washing machine to delay entering the spin-drying stage. In this embodiment, a third probe 33 works in conjunction with the reference probe 30 for detection, resulting in a more accurate assessment of the presence of water in the collection device 20. This allows for timely notification of whether the drainage process is complete, enabling the washing machine to execute the subsequent spin-drying process after drainage is finished, leading to higher overall washing program efficiency.

[0083] In this embodiment, when the washing machine receives a drainage command, the drainage device first performs a pre-draining process of opening and closing. During the pre-draining process, the drainage device remains fully open without stopping, and the amount of water discharged from the inner tub 10 to the water collection device 20 is limited, reducing the risk of overflow from the water collection device 20 in the initial stage of drainage. At the same time, the pre-draining process discharges a portion of the water from the inner tub 10, causing the water level in the inner tub 10 to drop, reducing the subsequent drainage rate of the inner tub 10. This makes it easier to control the opening and closing state of the drainage device through the water level detection device of the water collection device 20, thus preventing overflow from the water collection device 20.

[0084] In this embodiment, multiple probes with different installation heights are used as water level detection devices. Compared with traditional water level sensors, the error in water level detection results is smaller, and water level information is acquired more promptly. When two preset water levels are used to control the opening and closing timing of the drainage device, the difference between the first preset water level H1 and the second preset water level H2 can be maximized, preventing overflow of the water collection device 20 due to detection errors or delayed responses. Furthermore, increasing the difference between the first preset water level H1 and the second preset water level H2 can reduce the number of times the drainage device repeatedly opens and closes during drainage, thereby extending the service life of the drainage device, and thus extending the service life of the washing machine. On the other hand, the reduced frequency of drainage device operation also shortens the drainage time, thereby shortening the running time of the washing program and improving the user experience.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A control method for a washing machine, the washing machine comprising an inner tub independently holding water, a drain device for sealing or opening the inner tub to drain water, and a water collection device disposed at the bottom of the inner tub, wherein a water level detection device is disposed within the water collection device; during drainage, the drain device opens the drain outlet on the inner tub to drain water into the water collection device, and discharges the water through a drain pipe connected to the water collection device. Its features are, The water level detection device includes a reference probe, a first probe, and a second probe installed inside the water collection device. The first probe is installed higher than the reference probe, and the second probe is installed higher than the first probe. When the water level of the water collection device reaches the first preset water level H1, the reference probe and the first probe are connected through the washing water; when the water level of the water collection device reaches the second preset water level H2, the reference probe and the second probe are connected through the washing water, wherein H2 > H1. The control method includes the following steps: S1. The washing machine receives a drain command; S2. The drainage device performs a pre-drainage process of opening and closing, wherein when the drainage device is fully opened, the drainage device immediately performs a closing operation to stop drainage; S3. When the washing machine receives a signal that the reference probe and the first probe are disconnected, it controls the drainage device to start draining. S4. When the washing machine receives the signal that the reference probe and the second probe are turned on, it controls the drainage device to close and stop drainage, and returns to step S3.

2. The control method for a washing machine according to claim 1, characterized in that, The difference between the second preset water level H2 and the first preset water level H1 is greater than half the height of the water collection device.

3. The control method for a washing machine according to claim 1, characterized in that, The first probe is located in the lower region of the side wall of the water collection device, and the second probe is located in the upper region of the side wall of the water collection device.

4. The control method for a washing machine according to claim 3, characterized in that, The difference in installation height between the first probe and the second probe is close to the height of the water collection device.

5. The control method for a washing machine according to claim 1, characterized in that, In step S4, after the drainage device is turned off, if the washing machine does not receive a signal that the reference probe and the second probe are disconnected within the first preset time period, the drainage process is paused and the washing machine issues an alarm message.

6. The control method for a washing machine according to any one of claims 1-5, characterized in that, Between steps S3 and S4, there is also step S5: if the water level detection device detects that all the water in the water collection device has been discharged, the drainage process ends and the inner tub is controlled to rotate for dehydration; otherwise, step S4 is executed.

7. The control method for a washing machine according to claim 6, characterized in that, The water level detection device also includes a third probe, and both the reference probe and the third probe are set on the bottom wall of the water collection device; when there is water in the water collection device, the third probe and the reference probe are connected through the washing water; In step S5, if the washing machine receives a signal that the reference probe and the third probe have disconnected for a second preset time, the drainage process ends and the inner tub is controlled to rotate for spin-drying.

8. The control method for a washing machine according to any one of claims 1-5, characterized in that, The upper edge of the water collection device is lower than the opening of the inner bucket.

9. The control method for a washing machine according to any one of claims 1-5, characterized in that, The drainage device is a drain valve.

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