JP7478920B2 - Washing machine and method for controlling the washing machine - Google Patents

Description

The present invention relates to a washing machine that washes clothes, etc., and a method for controlling the washing machine.

Conventionally, washing machines have been considered that are equipped with a configuration for purifying the wash water by separating foreign matter such as dirt that has become detached from the laundry during washing (see, for example, Patent Document 1).

Figure 12 is a cross-sectional view of the main parts of the centrifugal separation unit installed in the conventional washing machine described in Patent Document 1. As shown in Figure 12, the conventional washing machine includes an outer tub (not shown), a centrifugal separation unit 51, a water passage 52, and a pump unit 53. The centrifugal separation unit 51 separates foreign matter contained in the washing water in the outer tub from the washing water. The water passage 52 circulates the washing water in the outer tub through the centrifugal separation unit 51. The pump unit 53 circulates the washing water in the outer tub through the centrifugal separation unit 51 provided in the water passage 52.

The centrifugal separation section 51 has a cylindrical case 54 connected in communication with the water passage 52, a cylindrical rotating cylinder 55 rotatably arranged within the case 54, pump impellers 53a integrally formed with the rotating cylinder 55, and a rotating cylinder motor 56 that rotates and drives the rotating cylinder 55. The pump impellers 53a are arranged within the pump section 53.

In a conventional washing machine, when the rotating barrel motor 56 is driven, the rotating barrel 55 and pump impeller 53a rotate, and the pumping action of the pump impeller 53a causes the wash water in the outer tub to flow in the direction of the arrow through the water passage 52 and circulate through the centrifugal separator 51. At this time, foreign matter such as soiling substances that have been washed off the laundry into the wash water during the wash operation are separated from the wash water by the centrifugal force generated by the high-speed rotation of the rotating barrel 55 and are held on the inner surface of the rotating barrel 55. This removes the foreign matter from the wash water. The wash water from which the foreign matter has been removed circulates between the centrifugal separator 51 and the outer tub, and purification progresses.

A washing machine has also been disclosed that removes foreign matter from the rotating drum 55 that has been centrifuged from the wash water and adhered to the inner surface of the rotating drum 55 (see, for example, Patent Document 2).

JP 2018-183277 A International Publication No. 2019/049697

However, in the conventional configuration, if the time it takes to separate foreign matter from the wash water by centrifugal force is long, the amount of foreign matter adhering to the inner surface of the rotating drum increases. Also, if the time that the foreign matter adhering to the inner surface of the rotating drum is subjected to centrifugal force is long, the force with which the foreign matter adheres to the inner surface of the rotating drum becomes stronger. Conventionally, the operation of removing foreign matter adhering to the inner surface of the rotating drum and the operation of draining the wash water containing the foreign matter were performed simultaneously, which resulted in the problem that the foreign matter could not be sufficiently removed in the specified drain time, and therefore could not be reliably drained by the drain operation.

The present invention aims to solve the above-mentioned problems of the conventional washing machine, and to provide a washing machine control method that can discharge foreign matter separated by centrifugal force from the washing water by a specified drainage operation.

In order to solve the above-mentioned problems, the washing machine of the present invention comprises a washing tub that contains the items to be washed and the washing water, a waterway that is provided so that the washing water is circulated outside the washing tub, a pump section provided in the waterway to circulate the washing water through the waterway, a centrifugal separation section provided in the waterway to centrifuge foreign matter contained in the circulating washing water, and a control section that controls at least the washing operation including the washing operation and the draining operation, the centrifugal separation section having a case through which the washing water passes, a rotating cylinder that is rotatably provided in the case to capture foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder, the control section is provided with a foreign matter removal operation that removes foreign matter captured on the inner surface of the rotating cylinder from the inner surface, and is configured to perform the foreign matter removal operation at least before the draining operation, and to discharge the foreign matter in the centrifugal separation section with the washing water during the draining operation.

As a result, even if a large amount of foreign matter is centrifuged out of the wash water and trapped on the inner surface of the rotating drum, or if the centrifugal force acting on the separated foreign matter causes the foreign matter to adhere strongly to the inner surface of the rotating drum, the foreign matter can be sufficiently discharged by performing the foreign matter removal operation with a specified drainage operation.

The washing machine of the present invention includes a washing tub that contains items to be washed and wash water, a waterway that circulates the wash water outside the washing tub, a pump unit that is provided in the waterway and circulates the wash water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating wash water by centrifugal separation, and a control unit that controls the washing operation including at least the washing operation and the draining operation. The centrifugal separator unit has a case through which the wash water passes, a rotating cylinder that is rotatably provided within the case and captures foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder. The control unit is configured to perform a foreign matter separation operation that drives the centrifugal separator unit and the pump unit during the washing operation, and to terminate the execution of the foreign matter separation operation midway through the washing operation.

This limits the amount of foreign matter that is separated from the wash water by centrifugation and the time that centrifugal force acts on the separated foreign matter, preventing the foreign matter from strongly adhering to the inner surface of the rotating drum, and allowing the foreign matter to be sufficiently discharged with a specified drainage operation.

The method of controlling a washing machine of the present invention includes a washing tub that contains items to be washed and washing water, a waterway that circulates the washing water outside the washing tub, a pump unit that is provided in the waterway and circulates the washing water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least a washing operation including a washing operation and a draining operation. The centrifugal separator unit has a case through which the washing water passes, a rotating cylinder that is rotatably provided in the case and captures foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder. The control unit includes a foreign matter removal operation that removes foreign matter captured on the inner surface of the rotating cylinder from the inner surface. The foreign matter removal operation is performed at least before the draining operation, and the foreign matter in the centrifugal separator unit is discharged by the washing water during the draining operation.

As a result, even if a large amount of foreign matter is centrifuged out of the wash water and trapped on the inner surface of the rotating drum, or if the centrifugal force acting on the separated foreign matter causes the foreign matter to adhere strongly to the inner surface of the rotating drum, the foreign matter can be sufficiently discharged by performing the foreign matter removal operation with a specified drainage operation.

In addition, the control method of the washing machine of the present invention includes a washing tub that contains items to be washed and wash water, a water channel that is arranged to circulate the wash water outside the washing tub, a pump section that is arranged in the water channel and circulates the wash water through the water channel, a centrifuge section that is arranged in the water channel and centrifuges foreign matter contained in the circulating wash water, and a control section that controls washing operations including at least a washing operation and a draining operation, wherein the centrifuge section has a case through which the wash water passes, a rotating cylinder that is rotatably arranged within the case and captures foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder, and during the washing operation, a foreign matter separation operation is performed to drive the centrifuge section and the pump section, and the execution of the foreign matter separation operation is terminated halfway through the washing operation.

This limits the amount of foreign matter that is separated from the wash water by centrifugation and the time that centrifugal force acts on the separated foreign matter, preventing the foreign matter from strongly adhering to the inner surface of the rotating drum, and allowing the foreign matter to be sufficiently discharged with a specified drainage operation.

The washing machine and washing machine control method of the present invention can sufficiently remove foreign matter separated by centrifugal force from the washing water by a specified drainage operation.

1 is a cross-sectional view showing a schematic configuration of a washing machine according to a first embodiment of the present invention; FIG. 3 is a cross-sectional view of a main part of a centrifugal separator of the washing machine according to the first embodiment; Block diagram of a washing machine according to a first embodiment Time chart showing the operation of the washing machine in the first embodiment A typical washing characteristic diagram of the washing machine in the first embodiment FIG. 13 is a diagram showing a combination of a foreign object separation operation and a foreign object removal operation of the washing machine in the first embodiment. FIG. 13 is a diagram showing combination patterns of foreign matter separation operation and foreign matter removal operation in the washing process and rinsing process of the washing machine in the first embodiment. Time chart showing another operation of the washing machine in the first embodiment Time chart showing another operation of the washing machine in the first embodiment Time chart showing another operation of the washing machine in the first embodiment Time chart showing another operation of the washing machine in the first embodiment FIG. 11 is a cross-sectional view of a schematic configuration of a washing machine according to a second embodiment. Time chart showing the operation of the washing machine in the second embodiment Time chart showing the operation of the washing machine in the third embodiment Cross-sectional view of the main part of the centrifugal separator installed in a conventional washing machine

Below, the embodiments will be described in detail with reference to the drawings. However, more detailed explanations than necessary may be omitted. For example, detailed explanations of matters that are already well known, or duplicate explanations of substantially identical configurations may be omitted. This is to avoid making the following explanation unnecessarily redundant and to make it easier for those skilled in the art to understand.

The accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

(Embodiment 1)
Hereinafter, the first embodiment will be described with reference to FIGS. 1 to 8D.

[1-1. Configuration]
Fig. 1 is a schematic cross-sectional view of a washing machine according to embodiment 1. In the following description, the left side shown in Fig. 1 and the like will be referred to as the front, the right side as the rear, the upper side as the upside, and the lower side as the downside.

As shown in Fig. 1, the washing machine has an outer tub 1 and a rotating tub 4 provided in the outer tub 1 as washing tubs for containing items to be washed and wash water. The outer tub 1 is formed in a cylindrical shape with a bottom, and is elastically supported by a plurality of suspension mechanisms 3 inside a housing 2 that constitutes the outer frame of the washing machine. The rotating tub 4 is also formed in a cylindrical shape with a bottom, and is provided so as to be rotatable about a tub rotation shaft 7. The rotating tub 4 has an input port 6 provided on the front side (left side in Fig. 1), and a user inserts and removes laundry 5, such as clothes, which are items to be washed, through the input port 6.

The peripheral wall surface of the rotating tub 4 is provided with multiple (e.g., three) baffles 8 protruding inward and numerous small holes 9. The outer tub 1 and the rotating tub 4 are connected through the small holes 9. The outer tub 1, the rotating tub 4, and the tub rotation shaft 7 are tilted upward (to the upper left in FIG. 1) at an angle θ (e.g., 20°) from the horizontal. The rotating tub 4 is connected to a motor 10 provided at the rear of the outer tub 1 via the tub rotation shaft 7, and is configured to rotate forward and backward freely. The motor 10 is, for example, a brushless DC motor, and is configured to be able to freely change the rotation speed by inverter control of the control unit 31 described later.

A door 11 formed in a substantially circular shape is provided on the front of the housing 2 to open and close the input port 6. The opening 1a of the outer tub 1 is formed opposite the input port 6 and is connected to an expandable bellows-shaped packing 12, ensuring a watertight structure between the outer tub 1 and the housing 2.

The water supply port 13 is provided at the upper rear surface of the housing 2. The water supply port 13 is connected to a water faucet 13a via a hose (not shown) or the like. As a result, tap water supplied from the water supply port 13 is supplied into the outer tub 1 as wash water. A water supply valve 14 and a detergent case 15 are provided downstream of the water supply port 13. The water supply valve 14 is driven to open and close by the control unit 31 to supply and stop the supply of wash water. Note that the wash water described in this embodiment 1 includes water containing detergent, water not containing detergent, rinse water during rinsing, etc.

The detergent case 15 includes a detergent dispenser 15a. The detergent dispenser 15a is configured to be able to be pulled out forward from the detergent case 15, as indicated by dotted arrow A. This allows the user to easily dispense detergent into the detergent case 15. Washing water is supplied to the detergent case 15 from the water supply port 13, as indicated by dotted arrow B, and flows into the outer tub 1 during the washing step of the washing operation described below, dissolving the detergent dispensed in the detergent case 15.

The drain outlet 16 is provided at the bottom of the outer tub 1. The drain passage 17 is connected to the drain outlet 16. The drain passage 17 is provided with a drain valve 18. The drain valve 18 is driven to open and close by the control unit 31. Specifically, when the drain valve 18 is closed, it stores the wash water supplied to the outer tub 1, and when it is open, it discharges the wash water in the outer tub 1 outside the machine.

One end of the water channel 19 is connected to the drainage channel 17 which is connected to the drain outlet 16. The other end of the water channel 19 is connected to the lower front part of the outer tub 1. The water channel 19 is composed of a first water channel 19a and a second water channel 19b which are connected to each other with the centrifugal separation section 20 in between. The first water channel 19a forms a flow path that allows the washing water in the outer tub 1 to flow into the centrifugal separation section 20 via the drainage channel 17. The second water channel 19b forms a flow path that allows the washing water that has passed through the centrifugal separation section 20 to flow into the washing tub 4.

That is, the wash water flows from the drain outlet 16 through the drain passage 17, through the first water passage 19a, the centrifugal separation section 20, and the second water passage 19b. At this time, foreign matter contained in the wash water is separated from the wash water by the centrifugal separation section 20 as it passes through the centrifugal separation section 20. Here, the foreign matter includes dirt and lint that have come loose from the laundry 5, water softeners contained in detergent dissolved in the wash water, etc.

The washing machine of the first embodiment is configured as described above.

Next, the configuration of the centrifugal separation unit 20 of the washing machine in this embodiment 1 will be described. Figure 2 is a cross-sectional view of the main part of the centrifugal separation unit of the washing machine in this embodiment 1.

The centrifuge section 20 has a case 21, a rotating cylinder 22, and a rotating cylinder motor 23. The case 21 is connected in communication with the water passage 19.

The rotating cylinder 22 is a hollow rotating cylinder rotatably arranged within the case 21, and is provided with a washing water inlet 22a and a washing water outlet 22b, and has an inner peripheral surface 22c, which is a cylindrical inner surface. Washing water in the outer tub 1 flows into the rotating cylinder 22 from the washing water inlet 22a through the first water passage 19a. Washing water that flows into the rotating cylinder 22 flows out from the washing water outlet 22b to the second water passage 19b. The washing water inlet 22a is provided in the center of the bottom surface of the rotating cylinder 22. The washing water outlet 22b is provided at the top of the rotating cylinder 22. With this configuration, washing water that passes through the centrifugal separation section 20 flows from the bottom to the top inside the rotating cylinder 22.

At this time, the control unit 31 drives the rotating cylinder motor 23 to rotate the rotating cylinder 22. The rotating shaft 22d of the rotating cylinder 22 is set vertically. The rotating cylinder motor 23 is set to rotate the rotating cylinder 22 at a high speed, for example, about 4000 rpm. As a result, the washing water introduced into the rotating cylinder 22 from the washing water inlet 22a generates a high-speed swirling flow along the rotation direction of the rotating cylinder 22. The swirling washing water flows out of the washing water outlet 22b provided at the top of the rotating cylinder 22 through the pump unit 24 and into the second water passage 19b. In other words, while passing through the rotating cylinder 22, the washing water is subjected to centrifugal force caused by the rotation of the rotating cylinder 22 by the driving of the rotating cylinder motor 23. Then, due to the action of the centrifugal force, foreign matter contained in the washing water is centrifuged. The separated foreign matter heads toward the inner circumferential surface 22c of the rotating cylinder 22 and adheres to and accumulates on the inner circumferential surface 22c.

The diameter of the inner circumferential surface 22c of the rotating cylinder 22 is configured to be larger than the maximum diameter of the washing water inlet 22a and the washing water outlet 22b. As a result, the centrifugal force acting on the foreign matter becomes stronger from the center, which is the rotation axis 22d of the rotating cylinder 22, toward the inner circumferential surface 22c. Therefore, the foreign matter separated by the centrifugal force is held on the inner circumferential surface 22c by the strong centrifugal force. This prevents the separated foreign matter from being drawn back into the circulating flow of washing water passing through the rotating cylinder 22 from the bottom to the top. As a result, it is possible to prevent the problem of dirt re-adhering to the laundry 5, and improve the cleaning power.

In the centrifugal separation section 20, the above-mentioned pump section 24 is provided on the outflow side of the wash water passing through the case 21. The pump section 24 is provided with pump vanes 24a formed integrally with the rotating cylinder 22. Although not shown, the pump section 24 is connected to the second water passage 19b at a position offset to the side from the center of rotation of the pump vanes 24a.

The pump blades 24a rotate together with the rotating barrel 22 when driven by the rotating barrel motor 23. This generates a pumping action on the wash water by the pump blades 24a. Due to the pumping action, the wash water in the outer tub 1 flows through the first water passage 19a and passes through the centrifugal separation section 20, as shown by arrow C in Figures 1 and 2, and circulates between the outer tub 1 and the centrifugal separation section 20 through the second water passage 19b.

The flow rate of the wash water flowing through the water passage 19 is set by the capacity of the pump section 24 and the diameter of the water passage. The capacity of the pump section 24 can be set by the number of pump blades 24a (8 in the present embodiment 1) and their shape, in addition to the rotation speed of the pump blades 24a.

In the circulating flow passing through the centrifugal separation section 20, when the flow velocity in the direction of the rotating shaft 22d is V1 and the flow velocity in the swirling direction is V2, the flow velocity V2 is set to be higher than the flow velocity V1 such that V2>V1. Note that the flow velocities V1 and V2 are set, for example, according to the capacity of the pump section 24, the size of the rotating shell 22, the number of rotations of the rotating shell 22 by the rotating shell motor 23, and the like.

Next, the configuration of the control unit 31 of the washing machine will be described. The control unit 31 is provided, for example, at the bottom inside the housing 2. As shown in FIG. 3, the control unit 31 receives the outputs of the water amount detection unit 32, the water amount detection unit 33, the rotation detection unit 34, the dirt detection unit 38, and the like. The cloth amount detection unit 32 detects the amount of laundry 5 placed in the spin tub 4. The water amount detection unit 33 detects the amount of wash water supplied to the outer tub 1. The rotation detection unit 34 detects the rotational drive of the spin tub 4. The dirt detection unit 38 detects the degree of dirtiness of the wash water, for example, by turbidity.

The control unit 31 also controls the operation of the motor 10, water supply valve 14, drain valve 18, rotating cylinder motor 23, etc., based on the washing course set by the user via the operation display unit 35 and the time measured by the built-in timer unit 36, and controls the washing operation including the water supply operation, washing operation, and drain operation described below. The washing operation includes, for example, the washing process, rinsing process, and spin-drying process.

The functions of the control unit 31 may be realized, for example, by a microcomputer and peripheral circuits.

The microcomputer and peripheral circuits may be in any form as long as they perform the control described below. The control unit 31 may be composed of an arithmetic processing unit and a storage unit that stores a control program. Examples of the arithmetic processing unit include an MPU (Micro Processing Unit) and a CPU (Central Processing Unit). Examples of the storage unit include a memory. The control program recorded in the storage unit is executed by the arithmetic processing unit.

The control unit 31 may also be configured with hard logic. Using hard logic is effective in improving processing speed. Each component may be configured with a single semiconductor chip, or may be physically configured with multiple semiconductor chips. When the control unit 31 is configured with multiple semiconductor chips, each control described below can be realized with a separate semiconductor chip.

[1-2. motion]
The operation and function of the washing machine configured as above will be described. The washing operation includes a washing step, a rinsing step, and a spin-drying step. Tap water is supplied to the washing step and the rinsing step. This includes a water supplying operation, a washing operation in which the spin tub 4 rotates to agitate the laundry 5, and a draining operation in which the wash water is discharged.

Each step will be described in detail. In the washing step, first, a water supply operation supplies wash water, in which detergent in the detergent case 15 is dissolved in tap water, to the outer tub 1. Next, a cleaning operation agitates the laundry 5 to beat it and wash away dirt from the laundry 5. Finally, a drain operation discharges the wash water containing the dirt from the laundry 5 outside the machine.

In the rinsing process following the washing process, first, tap water not containing detergent is supplied into the outer tub 1 as wash water by a water supply operation. Next, in a washing operation, the laundry 5 is agitated to disperse and dilute the detergent and dirt contained in the laundry 5 into the wash water, thereby rinsing the laundry. Finally, in a draining operation, the wash water in which the detergent and dirt from the laundry 5 has been diluted is discharged outside the machine. Here, the rinsing process may be performed multiple times, including an intermediate spin-drying operation after the draining operation.

Following the rinsing process, at the end of the washing operation, a spin-drying process is carried out to spin the wash water out of the laundry 5.

The actual washing operation will now be described in detail. First, the user opens the door 11 on the front of the housing 2 and inserts laundry 5 into the spin tub 4 through the insertion opening 6. Next, the user turns on the power switch (not shown) on the operation display unit 35 located on the upper front of the housing 2, and operates the start switch (not shown). This starts the washing operation.

When the washing operation is started, the control unit 31 first detects the amount of laundry 5 placed in the spin tub 4 by the fabric amount detection unit 32. Specifically, the fabric amount detection unit 32 detects the amount of laundry 5 from the amount of torque applied to the motor 10 when the spin tub 4 is rotated, or the current value of the motor 10, etc.

Next, the control unit 31 sets the time and amount of wash water for each process, such as the washing process, rinsing process, and spin-drying process, according to the detected amount of laundry 5. Additionally, the control unit 31 displays on the operation display unit 35 the amount of detergent that has been preset according to the amount of laundry 5. This allows the user to pull out the detergent dispenser 15a from the detergent case 15 and dispense detergent according to the estimated amount of detergent displayed on the operation display unit 35. After dispensing the detergent, the user moves the detergent dispenser 15a into the detergent case 15.

In the washing process, the water supply operation is started first. The control unit 31 detects that the detergent dispenser 15a has been placed in the detergent case 15 using the detergent case detection unit (not shown), starts the water supply operation, and opens the water supply valve 14. When the water supply valve 14 is opened, tap water flows into the detergent case 15 from the water supply port 13 as wash water, as shown by the dotted arrow B in FIG. 1. The flowing-in wash water is supplied into the outer tub 1 while dissolving the detergent dispenser 15a.

The washing water containing detergent that has accumulated at the bottom of the outer tub 1 flows into the spin tub 4 through the small hole 9. At this time, the control unit 31 detects the amount of washing water supplied to the outer tub 1 by the water amount detection unit 33. When the control unit 31 detects by the water amount detection unit 33 that a predetermined amount of washing water that is preset according to the amount of laundry 5 has been supplied, it closes the water supply valve 14 and completes the water supply operation.

Next, the process moves to the washing operation. When the water supply operation is completed, the control unit 31 starts the washing operation, and drives the motor 10 to rotate the spin tub 4. As the spin tub 4 rotates, the laundry 5 in the spin tub 4 is lifted in the direction of rotation by the baffle 8 and falls from above. The falling laundry 5 is slammed against the bottom of the spin tub 4 or against laundry 5 accumulated at the bottom of the spin tub 4, and is beaten and washed by the mechanical force of the fall in addition to the chemical force of the detergent. The rotation speed of the spin tub 4 when beating and washing the laundry 5 is, for example, 45 rpm, and the control unit 31 drives the motor 10 in forward and reverse rotation so that the washing tub 4 rotates forward and backward repeatedly at predetermined intervals.

Then, the draining operation begins. After performing the washing operation for a predetermined time, the control unit 31 transitions to the draining operation and opens the drain valve 18 to drain the wash water in the outer tub 1 outside the machine. When the control unit 31 detects via the water level detection unit 33 that the wash water has been drained, it closes the drain valve 18 and completes the draining operation.

After the washing process as described above is completed, the process proceeds to the rinsing process. In the rinsing process, as in the washing process, the control unit 31 supplies a predetermined amount of washing water into the outer tub 1 as a water supply operation. Note that the washing water supplied to the outer tub 1 in the rinsing process does not contain detergent. Thereafter, as a washing operation, the spin tub 4 is rotated to rinse the laundry 5. If intermediate spin-drying is performed at this time, the detergent and dirt contained in the laundry 5 are spin-dried together with the washing water, and the time for the rinsing process can be shortened. After the washing operation, as a drainage operation, the washing water in the outer tub 1 is discharged outside the machine.

In the spin-drying process, which is performed at the end of the washing operation, the control unit 31 opens the drain valve 18 to drain the washing water in the outer tub 1 outside the machine. The control unit 31 then drives the motor 10 to rotate the spin tub 4 containing the laundry 5 at high speed to spin-dry the laundry 5. When the spin-drying process is completed, the control unit 31 ends the washing operation.

The washing operation of the washing machine of the first embodiment is carried out as described above.

The action of purifying the wash water in the centrifugal separator 20 of the washing machine of the present embodiment 1 will be described below. In the washing process described above, the wash water contains various foreign matter such as soiling substances. For example, soiling substances include sand, fiber scraps, hair, keratinous dirt, and other substances that have a higher specific gravity than water. In addition, soiling substances include oils such as sebum that are lighter than water but adhere to things with a higher specific gravity than water, such as lint scraps.

Figure 4 is a time chart showing the operation of the washing operation of the washing machine in the present embodiment 1. Note that the washing process and rinsing process of the washing operation are shown, and the spin-drying process is omitted. As shown in Figure 4, in the washing process, the control unit 31 opens the water supply valve 14 to perform a water supply operation, and then closes the water supply valve 14 to start a cleaning operation. In the cleaning operation, a foreign object separation operation and a foreign object removal operation are performed. Each operation is described below.

First, the foreign matter separation operation will be described. With the water supply valve 14 and the drain valve 18 closed, the control unit 31 drives the rotating barrel motor 23 to circulate the wash water in the outer tub 1 to the centrifugal separation unit 20. Specifically, when the rotating barrel motor 23 is driven, the rotating barrel 22 and the pump blades 24a rotate integrally. Due to the pumping action of the pump blades 24a, the wash water in the outer tub 1 flows out of the drain port 16, passes through the first water passage 19a, and flows into the rotating barrel 22 from the wash water inlet section 22a. As described above, this wash water contains many foreign matters (dirty substances).

Since the rotating cylinder 22 is rotated at high speed by the rotating cylinder motor 23, the washing water that flows into the rotating cylinder 22 becomes a swirling flow within the rotating cylinder 22. As described above, foreign matter that is separated from the laundry and is heavier in specific gravity than the washing water is directed toward the inner circumferential surface 22c of the rotating cylinder 22 by the centrifugal force of this swirling flow, and adheres to and accumulates on the inner circumferential surface 22c. In this way, the soiling substances specific to the laundry that are contained in the washing water are centrifuged and removed from the washing water.

In other words, among the dirt contained in the wash water, those with a higher specific gravity than water (sand, hair, keratin dirt, etc.) and those with a lower specific gravity than water (such as grease such as sebum) adhere to and are separated from those with a higher specific gravity than water (such as lint), and can be removed from the wash water, allowing the separation of soiling substances specific to laundry contained in the wash water.

The rotation speed of the rotating drum 22 is the rotation speed at which the wash water is circulated and foreign matter is separated by centrifugal separation during the washing process or rinsing process. In the present embodiment 1, the rotation speed is set to, for example, 4000 rpm. The rotation speed of the rotating drum 22 is not limited to one, but may be set to multiple stages. For example, the dirt detection unit 38 detects the dirt in the wash water, and the control unit 31 varies the rotation speed of the rotating drum 22 depending on the dirt in the wash water.

The wash water from which the dirt substances have been separated in the rotating drum 22 flows out from the wash water outlet 22b to the pump section 24. The wash water that has flowed into the pump section 24 flows into the outer tub 1 through the second water passage 19b due to the pumping action of the pump blades 24a. The wash water in the outer tub 1 circulates between the centrifugal separation section 20 and the wash water in the centrifugal separation section 20 through the water passage 19 due to the pump function of the centrifugal separation section 20, and the purification of the wash water progresses. As described above, the foreign matter separation operation can prevent the separated dirt substances from re-adhering to the laundry 5.

As shown in FIG. 4, the control unit 31 executes a foreign object separation operation that drives the rotating cylinder motor 23 during the cleaning operation after the water supply operation in the washing step, and ends the execution of the foreign object separation operation in the middle of the cleaning operation. That is, the control unit 31 starts timing with the timer unit 36 when the cleaning operation starts, and executes the foreign object separation operation. The foreign object separation operation ends a predetermined elapsed time (t1) after the cleaning operation starts. At this time, the elapsed time t1 is set to be shorter than the cleaning operation time. t1 is, for example, 10 minutes.

Now, we will explain the elapsed time t1. Figure 5 shows typical washing characteristics when washing with a washing machine. The washing water and the amount of dirt on the laundry are shown on the vertical axis, and the washing time on the horizontal axis. When washing normally soiled laundry in the standard method, as shown by the laundry washing characteristics Da, most of the dirt on the laundry is removed before the set washing time t5 has elapsed, and after the elapsed time t1 from the start of the washing operation, the reduction in the amount of dirt on the laundry reaches a nearly saturated state da.

Therefore, even if the foreign matter separation operation is terminated during the washing operation after the elapsed time t1 from the start of the washing operation, most of the dirt on the laundry will have been removed, so the washing characteristics will not be impaired. Furthermore, by performing the foreign matter separation operation in the centrifugal separation section 20 for a time shorter than the total washing operation time, the amount of foreign matter that is centrifuged out of the wash water is reduced, and the adhesion force of the foreign matter is reduced by shortening the time that the centrifugal force acts on the separated foreign matter, making it possible to achieve both washing characteristics and foreign matter removal.

The elapsed time t1 is set in anticipation of the time it takes for foreign matter contained in the wash water to be captured by the centrifugal separation section 20. This anticipated time may be set through experiments or simulations.

The foreign object separation operation can also be terminated midway through the washing operation by detecting the degree of dirtiness of the wash water. The control unit 31 terminates the foreign object separation operation based on a decrease in the dirtiness of the wash water. More specifically, the dirtiness of the wash water is detected by the dirt detection unit 38, and the control unit 31 terminates the foreign object separation operation when it detects that the dirtiness of the wash water has been purified to a predetermined level.

As shown in FIG. 5, the wash water dirt characteristic Db is related to the laundry cleaning characteristic Da, and as the washing time progresses, the amount of dirt in the wash water increases due to dirt being washed off the laundry 5. Then, as the amount of dirt removed from the laundry 5 decreases, the increase in the amount of dirt in the wash water reaches db, which is almost saturated.

Therefore, if the dirt in the wash water has decreased to a predetermined level after the time t1 has elapsed since the start of the washing operation, even if the foreign matter separation operation is terminated during the washing operation, most of the dirt on the laundry 5 will have been removed and the washing characteristics will not be impaired.

Next, the foreign matter removal operation will be described. The foreign matter removal operation is started at least before the drainage operation, for example, during the cleaning operation. With the water supply valve 14 and the drainage valve 18 closed, the control unit 31 performs an operation to peel off and remove foreign matter adhering to the inner surface 22c of the rotating cylinder 22.

Specifically, the control unit 31 controls the rotating drum motor 23 so as to generate a speed difference between the flow speed of the wash water that flows with the rotation of the rotating drum 22 and the rotation speed of the rotating drum 22 .
For example, the control unit 31 controls the rotating barrel motor 23 so as to rapidly change the rotation speed of the rotating barrel 22 within a range of rotation speeds at which the foreign matter held on the inner circumferential surface 22c of the rotating barrel 22 can be dispersed. The rotation speed of the rotating barrel 22 is, for example, 50 rpm to 400 rpm.

At this time, the rotating drum 22 is filled with the washing water used in the washing process, and while the rotation speed of the rotating drum 22 changes rapidly, the flow rate of the washing water changes slowly. This creates a speed difference between the rotation speed of the foreign matter that is attached to and integrated with the inner circumferential surface 22c of the rotating drum 22 and the flow rate of the water. This speed difference therefore acts on the foreign matter as a shear force of the water, allowing the foreign matter to be peeled off and removed from the inner circumferential surface 22c of the rotating drum 22.

The control unit 31 rapidly drives the rotating barrel motor 23 in reverse to rotate the rotating barrel 22 forward and backward. For example, the rotating barrel motor 23 is driven forward for 1 second and reversely for 1 second. The shear force of the water can be repeatedly applied alternately in opposite directions to the foreign matter stuck to the inner surface 22c of the rotating barrel 22 each time the rotating barrel 22 is reversed. This makes it even easier to peel off and remove the foreign matter from the inner surface 22c of the rotating barrel 22.

At this time, the pump blades 24a formed integrally with the rotating barrel 22 are rapidly rotated forward and backward together with the rotating barrel 22. As a result, no pumping action occurs, and the circulation of the wash water is stopped. Therefore, the foreign matter removed from the inner surface 22c of the rotating barrel 22 does not flow from inside the rotating barrel 22 into the second water passage 19b and into the outer tub 1, and is prevented from reattaching to the laundry 5 in the outer tub 1.

In addition, the foreign object removal operation may be performed by rapidly rotating the rotating barrel 22 in one direction intermittently in addition to rapidly rotating the rotating barrel 22 forward and backward. In this case, short-term sudden movements and stops are repeated. For example, the ON time for energizing the rotating barrel motor 23 is 1 second, and the OFF time for deenergizing is 3 seconds. When the power supply to the rotating barrel motor 23 is stopped, the rotating barrel 22 rotates by inertia and gradually decreases in speed. After the OFF time from the deenergization of the rotating barrel motor 23, the control unit 31 controls the rotating barrel motor 23 so that the rotation of the rotating barrel 22 is suddenly accelerated during the inertial rotation of the rotating barrel 22, and this sudden acceleration operation is repeated. In short, it is sufficient that the operation is performed so that a speed difference occurs between the flow speed of the water and the foreign objects attached to the inner circumferential surface 22c of the rotating barrel 22, and a shear force due to the resistance of the water acts on the foreign objects. The ON time and rotation speed of the rotating barrel motor 23 are within a range in which the washing water does not circulate. In addition, during the foreign matter removal operation, the control unit 31 may rotate the rotating cylinder 22 in a separate operation to remove foreign matter adhering to the inner circumferential surface 22c of the rotating cylinder 22.

After the foreign matter separation operation is completed, the control unit 31 starts the foreign matter removal operation before the drainage operation begins, and starts timing with the timer unit 36. The control unit 31 ends the foreign matter removal operation a predetermined time (t2) after the start of the foreign matter removal operation. At this time, the time t2 may be set longer than the drainage time t3. For example, by setting the foreign matter removal operation time t2 longer than the discharge time t3, the foreign matter removal operation can be performed for a longer period of time than if it were performed only during the drainage operation (time t3). This allows the foreign matter to be sufficiently removed. For example, t2 is 1 minute, and t3 is 30 seconds.

The foreign object removal operation may also end during or at the end of the cleaning operation. Alternatively, the foreign object removal operation may end during the drainage operation of the washing step. In short, it is sufficient that there is wash water in the rotating drum 22.

That is, the control unit 31 executes the foreign matter removal operation while the wash water used in the washing process is still in the rotating drum 22. This allows the foreign matter removal operation to be executed before the draining operation, and the foreign matter adhering to the inner circumferential surface 22c of the rotating drum 22 can be easily removed by utilizing the shear force caused by the resistance of the wash water. Then, in the draining operation, the removed foreign matter is discharged outside the machine through the opened drain valve 18 together with the wash water flowing in the opposite direction to the direction circulating through the water passage 19, i.e., in the draining direction.

In this way, the foreign matter removal operation is performed at least before the discharge of the wash water begins, so that even if a large amount of foreign matter is centrifuged from the wash water and captured on the inner surface 22c of the rotating drum 22, or if the separated foreign matter adheres strongly to the inner surface 22c of the rotating drum 22 due to the centrifugal force acting on the separated foreign matter, the foreign matter removed by the specified drainage operation can be discharged.

In addition, by performing the foreign matter removal operation after the foreign matter separation operation has been completed during the washing operation and before the drainage operation, the amount of foreign matter that is separated from the wash water in the centrifuge section and the time that centrifugal force acts on the captured foreign matter are limited, and it is possible to prevent the foreign matter from strongly adhering to the inner surface 22c of the rotating cylinder 22. Furthermore, since the foreign matter removal operation is performed when the foreign matter that has adhered to the inner surface 22c of the rotating cylinder 22 is likely to peel off before it adheres strongly, the foreign matter can be easily removed from the inner surface 22c of the rotating cylinder 22 and discharged together with the wash water.

Also, as shown in FIG. 4, the foreign matter removal operation may be performed in the rinsing process. In the rinsing process, the washing water used in the washing process is discharged and new washing water is supplied to perform the foreign matter removal operation. Also, before this water supply operation, an intermediate spin-drying operation may be performed in which the washing water containing dirt is spin-dried from the laundry 5. In this case, the rinsing process is suitable for performing a foreign matter removal operation to peel off foreign matter from the inner circumferential surface 22c of the rotating cylinder 22 when the washing water contains a small amount of foreign matter and the foreign matter centrifuged in the washing process remains on the inner circumferential surface 22c of the rotating cylinder 22.

The foreign matter removal operation is performed during the rinsing process, as well as during the washing process, at least before the draining process. The pump blades 24a, which are formed integrally with the rotating barrel 22, are rapidly rotated forward and backward together with the rotating barrel 22. As a result, no pumping action occurs, and no circulation of wash water occurs. Therefore, foreign matter that has peeled off from the inner surface 22c of the rotating barrel 22 does not flow from inside the rotating barrel 22 into the second water passage 19b and into the outer tub 1, and is prevented from reattaching to the laundry 5.

In the rinsing step of FIG. 4, the foreign matter separation operation is not performed, so the foreign matter removal operation may be performed at any time during the cleaning operation. The time t4 for the operation may be set arbitrarily, similar to the time t2. t4 is, for example, one minute.

As described above, in FIG. 4, a time chart showing the operation of the washing machine of the first embodiment has been explained, but it will be explained that the combination of the foreign object separation operation and the foreign object removal operation is not limited to this. FIG. 6 shows a combination of the foreign object separation operation and the foreign object removal operation in the washing operation. Also, FIG. 7 shows a combination pattern of the foreign object separation operation and the foreign object removal operation in the washing process and the rinsing process.

Figure 6 shows that in one cleaning operation, combination A performs both a foreign object separation operation and a foreign object removal operation. Similarly, combination B performs only a foreign object removal operation, and combination C performs only a foreign object separation operation. Combination D performs neither operation.

Fig. 7 explains combination patterns of the foreign matter separation operation and the foreign matter removal operation in the washing process and the rinsing process, using combinations A to D in Fig. 6. For example, the combination in the embodiment in Fig. 4 shows that the washing process is performed in combination A, and the rinsing process is performed in combination B. However, the combination patterns of the foreign matter separation operation and the foreign matter removal operation are not limited to this, and in other embodiments, the washing process and the rinsing process may be performed in any of combinations A, B, and C. Furthermore, depending on the state of the laundry 5 and the operating conditions, there may be a combination D in which neither the foreign matter separation operation nor the foreign matter removal operation is performed.

As an example, combination patterns of foreign matter separation operation and foreign matter removal operation are shown in Figures 8A, 8B, 8C, and 8D. In Figure 8A, foreign matter separation operation and foreign matter removal operation are performed in both the washing process and the rinsing process (combination A). In Figure 8B, foreign matter separation operation and foreign matter removal operation are performed in the washing process (combination A), and foreign matter separation operation is performed in the rinsing process (combination C). In Figure 8C, foreign matter separation operation is performed in the washing process (combination C), and foreign matter separation operation and foreign matter removal operation are performed in the rinsing process (combination A). In Figure 8D, foreign matter separation operation is performed in the washing process (combination C), and foreign matter removal operation is performed in the rinsing process (combination B).

In any case, if the foreign object separation operation is performed in the washing step, the foreign object removal operation may be performed in the washing step or the rinsing step after that. Alternatively, it may be performed in both the washing step and the rinsing step. Also, the foreign object separation operation may be performed in the rinsing step. Then, these combination patterns may be set and changed each time a washing operation is performed. The setting may be changed by the user. Alternatively, the combination pattern may be set by the control unit 31. For example, the control unit 31 selects a combination pattern according to the amount of laundry 5 detected by the cloth amount detection unit 32. Also, during the washing operation, the control unit 31 selects a combination pattern according to the dirt in the washing water detected by the dirt detection unit 38.

The foreign matter removal operation may be performed when the washing machine is not in use. For example, the foreign matter removal operation may be performed after the end of a washing operation or after each predetermined number of washing operations. In this case, the control unit 31 opens the water supply valve 14, detects the amount of tap water supplied from the water supply port 13 using the water amount detection unit 33, and closes the water supply valve 14 when the case 21 of the centrifuge unit 20 is filled with water, thereby performing the foreign matter removal operation. The control unit 31 then opens the drain valve 18 to discharge the removed foreign matter.

[1-3. Effects, etc.]
As described above, in the first embodiment, the washing machine includes a washing tub that contains articles to be washed and wash water, a water passage 19 that is provided so that the wash water is circulated outside the washing tub, a pump unit 24 that is provided in the water passage 19 and circulates the wash water through the water passage 19, a centrifugal separation unit 20 that is provided in the water passage 19 and separates foreign matter contained in the circulating wash water by centrifugal separation, and a control unit 31 that controls at least a washing operation including a washing operation and a draining operation. The centrifugal separation unit 20 has a case 21 through which the wash water passes, a rotating cylinder 22 that is rotatably provided within the case 21 and captures foreign matter, and a rotating cylinder motor 23 that rotates and drives the rotating cylinder 22. The control unit 31 is provided with a foreign matter removal operation that removes foreign matter captured on the inner circumferential surface 22c of the rotating cylinder 22 from the inner circumferential surface 22c, and is configured to perform the foreign matter removal operation at least before performing the draining operation, and to discharge the foreign matter in the centrifugal separation unit 20 by the wash water during the draining operation.

The control method for a washing machine includes a washing tub that contains items to be washed and washing water, a waterway 19 that is provided so that the washing water is circulated outside the washing tub, a pump unit 24 that is provided in the waterway 19 and circulates the washing water to the waterway 19, a centrifugal separator unit 20 that is provided in the waterway 19 and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit 31 that controls at least a washing operation including a washing operation and a draining operation. The centrifugal separator unit 20 has a case 21 through which the washing water passes, a rotating cylinder 22 that is rotatably provided in the case 21 and captures foreign matter, and a rotating cylinder motor 23 that drives the rotating cylinder 22 to rotate. The control unit 31 is provided with a foreign matter removal operation that removes foreign matter captured on the inner circumferential surface 22c of the rotating cylinder 22 from the inner circumferential surface 22c. The foreign matter removal operation is performed at least before the draining operation, and the foreign matter in the centrifugal separator unit 20 is discharged by the washing water during the draining operation.

With this type of washing machine and washing machine control method, even if a large amount of foreign matter is centrifuged from the wash water and captured on the inner surface 22c of the rotating drum 22, or if the separated foreign matter adheres strongly to the inner surface 22c of the rotating drum 22 due to the centrifugal force acting on the foreign matter, the foreign matter can be sufficiently discharged by a specified drainage operation by performing a foreign matter removal operation.

During the foreign matter removal operation, the control unit 31 is configured to control the rotating barrel motor 23 so as to create a speed difference between the flow rate of the wash water that flows with the rotation of the rotating barrel 22 and the rotation speed of the rotating barrel 22. This allows a shear force to be applied to the foreign matter adhering to the inner circumferential surface 22c of the rotating barrel 22, making it easier to remove the foreign matter from the inner circumferential surface 22c of the rotating barrel 22.

The control unit 31 is also configured to start a foreign matter removal operation in the middle of the cleaning operation. This allows the foreign matter removal operation to be executed when the foreign matter adhering to the inner circumferential surface 22c of the rotating cylinder 22 is likely to peel off before it becomes firmly attached, so that the foreign matter can be easily removed from the inner circumferential surface 22c of the rotating cylinder 22.

The control unit 31 is also configured to stop the circulation of the wash water when the foreign matter removal operation is being performed. This prevents the foreign matter removed during the foreign matter removal operation from being supplied to the washing tub through the second water passage 19b, thereby preventing the foreign matter from reattaching to the laundry 5.

The pump unit 24 also functions as the rotating barrel motor 23 and is configured to be integrated with the centrifugal separation unit 20, and the control unit 31 is configured to drive the rotating barrel motor 23 at a rotation speed at which the wash water does not circulate to perform the foreign matter removal operation. As a result, the pump unit 24 is simplified in configuration by being integrated with the centrifugal separation unit 20. When the foreign matter removal operation is performed, the circulation of the wash water is automatically stopped.

The washing machine is equipped with a washing tub that contains the items to be washed and the washing water, a waterway 19 that is provided so that the washing water is circulated outside the washing tub, a pump unit 24 that is provided in the waterway 19 and circulates the washing water to the waterway 19, a centrifugal separator unit 20 that is provided in the waterway 19 and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit 31 that controls at least the washing operation including the washing operation and the draining operation. The centrifugal separator unit 20 has a case 21 through which the washing water passes, a rotating cylinder 22 that is rotatably provided within the case 21 and captures foreign matter, and a rotating cylinder motor 23 that drives the rotating cylinder 22 to rotate. The control unit 31 is configured to perform a foreign matter separation operation that drives the centrifugal separator unit 20 and the pump unit 24 during the washing operation, and to terminate the execution of the foreign matter separation operation during the washing operation.

The method for controlling a washing machine includes a washing tub that contains items to be washed and washing water, a waterway 19 that is provided to circulate the washing water outside the washing tub, a pump unit 24 that is provided in the waterway 19 and circulates the washing water to the waterway 19, a centrifugal separator unit 20 that is provided in the waterway 19 and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit 31 that controls at least the washing operation including the washing operation and the draining operation. The centrifugal separator unit 20 has a case 21 through which the washing water passes, a rotating cylinder 22 that is rotatably provided within the case 21 and captures foreign matter, and a rotating cylinder motor 23 that drives the rotating cylinder 22. In the washing operation, the method performs a foreign matter separation operation that drives the centrifugal separator unit 20 and the pump unit 24, and ends the execution of the foreign matter separation operation in the middle of the washing operation.

This type of washing machine and washing machine control method limits the amount of foreign matter that is separated from the wash water by centrifugation in the centrifuge section 20 and the time that centrifugal force acts on the separated foreign matter, thereby preventing the foreign matter from strongly adhering to the inner surface 22c of the rotating cylinder 22.

In addition, the control unit 31 performs a foreign matter removal operation before performing a drainage operation after completing a foreign matter separation operation during the washing operation, thereby performing a foreign matter removal operation when foreign matter attached to the inner surface 22c of the rotating drum 22 is likely to peel off before it becomes firmly attached, so that the foreign matter can be easily removed from the inner surface 22c of the rotating drum 22 and discharged together with the wash water.

The control unit 31 is also configured to terminate the foreign object separation operation based on the elapsed time since the start of the cleaning operation. This allows the foreign object separation operation performed in the cleaning operation to be optimized based on the elapsed time.

The time that has elapsed since the start of the washing operation is set in anticipation of the time it takes for foreign objects contained in the wash water to be captured by the centrifugal separation unit 20. This allows the foreign object separation operation performed during the washing operation to be optimized based on the time it takes for the foreign objects to be captured.

The control unit 31 is also configured to terminate the foreign matter separation operation based on the reduction in dirtiness of the wash water. This allows the foreign matter separation operation performed in the washing operation to be optimized based on the reduction in dirtiness of the wash water.

The washing machine also includes a dirt detection unit 38 that detects dirt in the wash water, and the control unit 31 is configured to detect when the dirt in the wash water has been purified to a predetermined state by the dirt detection unit 38. This allows the reduction in dirt in the wash water to be accurately grasped, and the foreign matter separation operation performed during the washing operation can be optimized based on the state of purification of the wash water.

The washing machine further includes a drainage channel 17 that branches off from the water channel 19 to drain the washing water outside the machine, and a drainage valve 18 provided in the drainage channel 17, and the control unit 31 is configured to open the drainage valve 18 to drain the washing water. This allows foreign matter removed from the rotating drum 22 to be discharged through the drainage channel 17 together with the washing water, thereby cleaning the inside of the rotating drum 22.

(Embodiment 2)
[2-1. Configuration]
9 is a schematic cross-sectional view of a washing machine according to the second embodiment. The second embodiment is characterized in that pump unit 37 is configured independently of centrifugal separator 20, and control unit 31 drives pump unit 37 to circulate the washing water in outer tub 1 and executes a foreign matter separating operation. Control unit 31 also stops driving pump unit 37 to execute a foreign matter removing operation. Other configurations are the same as those of the first embodiment, and the same reference numerals are used for the same configurations, and the detailed description of the first embodiment is incorporated.

As shown in FIG. 9, a pump unit 37 is provided in the water passage 19 to circulate the wash water in the outer tub 1. The pump unit 37 is provided in the second water passage 19b, downstream of the centrifugal separation unit 20, and is driven by a motor (not shown) different from the rotating barrel motor 23 that drives the rotating barrel 22 to rotate. In other words, the centrifugal separation unit 20 does not have a pump function for circulating the wash water, and the circulation of the wash water is performed by the pump unit 37.

In addition, the pump unit 37 is not driven during the draining operation, and the washing water is naturally discharged by gravity, and the pump unit 37 is configured not to impede the discharge of the washing water from the rotating cylinder 22. Alternatively, the pump unit 37 is configured to be freely rotatable in both directions, and may be driven to flow the washing water in the draining direction during the draining operation.

The pump section 37 may be provided in the first water passage 19a, which is upstream of the centrifugal separation section 20.

[2-2. motion]
The actual operation will be described in detail below. The control unit 31 controls the washing operation in the same manner as in the first embodiment. Fig. 10 is a time chart showing the operation of the washing process of the washing machine in the second embodiment. In addition, the rinsing process of the washing operation is omitted because it is the same as that of the first embodiment shown in Fig. 4. The foreign matter separating operation and the foreign matter removing operation will be described below.

During the washing operation, a foreign matter separation operation is performed. That is, the control unit 31 drives the rotating barrel motor 23 to rotate the rotating barrel 22 at high speed, and centrifuges the foreign matter contained in the washing water in the centrifugal separation unit 20. At this time, the control unit 31 drives the pump unit 37 in the forward direction, and circulates the washing water in the outer tub 1 to the centrifugal separation unit 20 through the water passage 19, as shown by arrow C in FIG. 9.

After the foreign object separation operation, the foreign object removal operation is performed. At this time, the control unit 31 stops driving the pump unit 37 and stops the circulation of the wash water. The foreign object removal operation may end at the end of the washing operation, or during or at the end of the next drainage operation.

Following the above washing operation, the control unit 31 executes a draining operation. At this time, the control unit 31 opens the drain valve 18 without driving the pump unit 37, and the washing water is naturally discharged by gravity. Alternatively, the control unit 31 may open the drain valve 18 and drive the pump unit 37 in reverse to encourage the washing water to flow in the draining direction.

Although not shown, a foreign matter removal operation may be performed during the washing operation of the rinsing step as shown in FIG. 10. Also, a foreign matter removal operation may be performed during the washing operation as shown in FIG. 10 without performing a foreign matter separation operation.

[2-3. Effects, etc.]
As described above, in the present embodiment 2, the pump unit 37 is configured independently of the centrifugal separation unit 20, and the control unit 31 is configured to stop driving the pump unit 37 and execute the foreign matter removal operation. This prevents the foreign matter removed by the foreign matter removal operation from being supplied to the washing tub through the water passage 19, and prevents the foreign matter from reattaching to the laundry 5. The control unit 31 can also individually control the pump unit 37 and the centrifugal separation unit 20 to accurately control the circulation and stop of the wash water.

The pump unit 37 is configured so that the washing water flows in the draining direction during the draining operation. This allows the washing water to be drained naturally, and the pump unit 37 does not hinder the draining of the washing water. Furthermore, if the pump unit 37 is driven in the reverse direction, the washing water in the rotating cylinder 22 is quickly drained.

(Embodiment 3)
[3-1. Configuration]
The configuration of the washing machine is the same as that of the second embodiment, and the same components are denoted by the same reference numerals, and the detailed description thereof will be referred to that of the second embodiment. The third embodiment is characterized in that a drainage operation is temporarily performed during the foreign matter removal operation to discharge foreign matter from within the centrifugal separation unit 20.

[3-2. motion]
The actual operation will be described in detail below. The control unit 31 controls the washing operation in the same manner as in the first embodiment. Fig. 11 is a time chart showing the operation of the washing process of the washing machine in the third embodiment. As in the second embodiment, the rinsing step of the washing operation is the same as that in the first embodiment shown in Fig. 4 and is therefore omitted. The foreign matter separating operation and the foreign matter removing operation will be described below.

As in the second embodiment, the control unit 31 drives the rotating barrel motor 23 as a foreign matter separation operation during the washing operation, rotating the rotating barrel 22 at high speed to separate foreign matter contained in the wash water in the centrifugal separator 20. At this time, the control unit 31 drives the pump unit 37 in the forward direction, and circulates the wash water in the outer tub 1 to the centrifugal separator 20 through the water passage 19 as shown by arrow C in FIG. 9. After the foreign matter separation operation is performed, a foreign matter removal operation is performed. At this time, the control unit 31 stops driving the pump unit 37 and stops the circulation of the wash water. Up to this point, it is the same as in the second embodiment.

Then, as shown in FIG. 11, the control unit 31 drives the pump unit 37 in the opposite direction to the circulation for a short time (t6) during the foreign object removal operation, and opens the drain valve 18 to drain the wash water in the rotating drum 22. t6 is a time for which some or all of the wash water in the rotating drum 22 flows into the first water passage 19a, for example, 2 seconds. As a result, the wash water in the rotating drum 22, including the foreign objects peeled off by the foreign object removal operation, is discharged outside the machine through the drain valve 18. As the wash water in the rotating drum 22 flows out, the wash water in the outer tub 1 flows into the rotating drum 22 from the second water passage 19b, replacing the wash water in the rotating drum 22.

After performing a temporary drainage operation, the control unit 31 stops driving the pump unit 37 and closes the drainage valve 18 to continue the foreign matter removal operation. The foreign matter removal operation may end when the cleaning operation ends, or may end during or at the end of the next drainage operation.

Following the above washing operation, the control unit 31 executes the draining operation. At this time, the control unit 31 opens the drain valve 18 without driving the pump unit 37, and the washing water is naturally discharged by gravity. Alternatively, the control unit 31 may drive the pump unit 37 in the reverse direction to encourage the washing water to flow in the draining direction.

In the third embodiment, the temporary drainage operation may be natural drainage in which the control unit 31 opens the drain valve 18 without driving the pump unit 37. For example, in a washing machine in which the pump unit 37 doubles as the rotary barrel motor 23 and is integrated with the centrifugal separator unit 20 as in the configuration of FIG. 1, the temporary drainage operation can be performed by opening the drain valve 18 during the foreign matter removal operation.

Although not shown, a foreign matter removal operation may be performed during the washing operation of the rinsing step as shown in FIG. 11. Also, a foreign matter removal operation may be performed during the washing operation as shown in FIG. 11 without performing a foreign matter separation operation.

[3-3. Effects, etc.]
As described above, in this embodiment 3, the control unit 31 is configured to temporarily perform a short-term drainage operation while performing the foreign matter removal operation, to discharge the foreign matter within the centrifugal separation unit 20.

As a result, the wash water in the rotating barrel 22 is discharged along with the removed foreign matter, preventing the foreign matter from re-adhering to the laundry 5. In addition, the wash water in the rotating barrel 22 flows in the drain direction, causing the water in the washing tub to flow into the rotating barrel 22. As the water in the rotating barrel 22 is replaced, the concentration of foreign matter contained in the wash water in the rotating barrel 22 that was removed by the foreign matter removal operation can be reduced. As a result, foreign matter adhering to the inner surface 22c of the rotating barrel 22 is more likely to move to the wash water with a lower concentration of foreign matter, facilitating the removal of the foreign matter.

In particular, after the portion of the foreign matter that is attached in layers to the inner circumferential surface 22c of the rotating barrel 22 that is in contact with the inner circumferential surface 22c of the rotating barrel 22 is dispersed into the wash water, the wash water enters between the layer of foreign matter and the inner circumferential surface 22c of the rotating barrel 22 instead of the foreign matter, so that the layer of foreign matter tends to peel off from the inner circumferential surface 22c of the rotating barrel 22 in a lump. This condition is particularly likely to occur when fine particles of foreign matter are accumulated on the inner circumferential surface 22c of the rotating barrel 22.

Other Embodiments
As described above, the first to third embodiments have been described as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited to these, and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made. In addition, it is also possible to combine the components described in the first to third embodiments to create new embodiments.

Therefore, other embodiments are given below as examples.

In the first to third embodiments, as an example of the foreign matter separation operation, the control unit 31 has been described as starting the foreign matter separation operation simultaneously with the start of the cleaning operation in the washing step. However, the control unit 31 may not start the foreign matter separation operation simultaneously with the cleaning operation, but may execute it after a predetermined time has elapsed. This prevents the cleaning components contained in the cleaning water from being separated when the cleaning operation starts.

In the first to third embodiments, a drum-type washing machine has been described as an example of a washing machine, but the present invention is not limited to this. In short, any washing machine that uses wash water to wash laundry may be used. In other words, the present invention can be applied to washing machines of any configuration, such as a drum-type washing machine that performs beating wash, a vertical washing machine that performs agitation wash, or a washing machine that performs push wash or shower wash inside a storage case.

As described above, the washing machine of this embodiment includes a washing tub that contains the items to be washed and the washing water, a waterway that circulates the washing water outside the washing tub, a pump unit that is provided in the waterway and circulates the washing water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least the washing operation including the washing operation and the draining operation. The centrifugal separator unit has a case through which the washing water passes, a rotating cylinder that is rotatably provided in the case and captures foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder. The control unit includes a foreign matter removal operation that removes foreign matter captured on the inner surface of the rotating cylinder from the inner surface, and is configured to perform the foreign matter removal operation at least before the draining operation and to discharge foreign matter in the centrifugal separator unit with the washing water during the draining operation.

With this, even if a large amount of foreign matter is centrifuged out of the wash water and trapped on the inner surface of the rotating drum, or if the separated foreign matter adheres strongly to the inner surface due to the centrifugal force, the foreign matter can be sufficiently discharged with a specified drainage operation.

The control unit of the washing machine in this embodiment is configured to control the rotating drum motor during the foreign object removal operation so as to create a speed difference between the flow rate of the wash water that flows with the rotation of the rotating drum and the rotation speed of the rotating drum.

This allows a shear force to be applied to the foreign matter adhering to the inner surface of the rotating cylinder, making it easier to remove the foreign matter from the inner surface of the rotating cylinder.

The control unit of the washing machine in this embodiment is also configured to start the foreign object removal operation in the middle of the washing operation.

By doing this, the foreign matter removal operation is performed when foreign matter attached to the inner surface of the rotating cylinder is likely to peel off before it becomes firmly attached, so foreign matter can be easily removed from the inner surface of the rotating cylinder.

The control unit of the washing machine in this embodiment is also configured to stop the circulation of wash water when the foreign object removal operation is being performed.

This prevents foreign objects that are removed during the foreign object removal operation from being fed through the waterway into the washing tub, preventing the foreign objects from reattaching to the laundry.

The pump section of the washing machine in this embodiment is also configured as an integral part of the centrifugal separator, and the control section is configured to drive the rotating barrel motor at a rotation speed at which the wash water does not circulate to perform the foreign object removal operation.

This prevents foreign matter that has been removed during the foreign matter removal operation from being supplied to the washing tub through the waterway, preventing the foreign matter from reattaching to the laundry. In addition, the pump section is simplified in configuration by being integrated with the centrifugal separation section. And when the foreign matter removal operation is performed, the circulation of the wash water is automatically stopped.

In addition, the pump section of the washing machine in this embodiment is configured independently of the centrifugal separation section, and the control section is configured to stop driving the pump section and perform the foreign object removal operation.

This prevents foreign objects that have been removed during the foreign object removal operation from being fed through the waterway into the washing tub, preventing the foreign objects from reattaching to the laundry. The control unit also controls the independent pump unit and centrifugal separator unit separately, allowing it to accurately control the circulation and stopping of the wash water.

The pump section of the washing machine in this embodiment is configured so that the wash water flows in the drain direction during the draining operation.

By doing this, the washing water in the rotating drum flows in the drainage direction together with the foreign objects that have been removed, preventing the foreign objects from reattaching to the laundry. In addition, the washing water in the rotating drum is discharged by the pump section.

The control unit of the washing machine in this embodiment is also configured to temporarily perform a drainage operation while the foreign object removal operation is in progress, to expel foreign objects from within the centrifugal separator.

By doing this, the washing water in the rotating drum is discharged together with the foreign objects that have peeled off, preventing the foreign objects from reattaching to the laundry. In addition, the washing water in the rotating drum flows in the drain direction, causing the water in the washing tub to flow into the rotating drum, and the water in the rotating drum is replaced during the foreign object removal operation, facilitating the removal of the foreign objects.

The washing machine of this embodiment includes a washing tub that contains the items to be washed and the wash water, a waterway that circulates the wash water outside the washing tub, a pump unit that is provided in the waterway and circulates the wash water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating wash water by centrifugal separation, and a control unit that controls at least the washing operation including the washing operation and the draining operation. The centrifugal separator unit has a case through which the wash water passes, a rotating cylinder that is rotatably provided within the case and captures foreign matter, and a rotating cylinder motor that rotates and drives the rotating cylinder. The control unit is configured to perform a foreign matter separation operation that drives the centrifugal separator unit and the pump unit during the washing operation, and to terminate the execution of the foreign matter separation operation midway through the washing operation.

This limits the amount of foreign matter that is separated from the wash water in the centrifuge section and the time that centrifugal force acts on the separated foreign matter, preventing the foreign matter from strongly adhering to the inner surface of the rotating drum.

The control unit of this embodiment is also configured to terminate the foreign object separation operation based on the time that has elapsed since the cleaning operation was started.

This allows the foreign object separation operation performed during the cleaning operation to be optimized based on the elapsed time.

In addition, in the washing machine of this embodiment, the elapsed time is set to take into account the time it takes for foreign objects contained in the wash water to be captured by the centrifugal separator.

This allows the foreign object separation operation performed during the cleaning operation to be optimized based on the time it takes for the foreign object to be captured.

The control unit of the washing machine in this embodiment is also configured to end the foreign object separation operation based on a decrease in the dirtiness of the wash water.

This allows the foreign object separation operation performed during the washing operation to be optimized based on the reduction in dirt in the wash water.

The washing machine of this embodiment also includes a dirt detection unit that detects dirt in the wash water, and the control unit is configured to detect when the dirt in the wash water has been purified to a predetermined state by the dirt detection unit.

This allows the degree of dirt in the wash water to be accurately determined, and the foreign matter separation operation performed during the washing operation can be optimized based on the state of purification of the wash water.

The washing machine of this embodiment further includes a drainage channel that branches off from the water channel to drain the wash water outside the machine, and a drainage valve provided in the drainage channel, and the control unit is configured to open the drainage valve to drain the wash water during the draining operation.

This allows foreign matter that is torn off inside the rotating drum to be discharged through the drainage channel together with the wash water, keeping the inside of the rotating drum clean.

The control method for a washing machine according to the present embodiment includes a washing tub that contains items to be washed and washing water, a waterway that circulates the washing water outside the washing tub, a pump unit that is provided in the waterway and circulates the washing water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least a washing operation including a washing operation and a draining operation. The centrifugal separator unit has a case through which the washing water passes, a rotating cylinder that is rotatably provided in the case and that captures foreign matter, and a rotating cylinder motor that drives the rotating cylinder to rotate. The control unit is provided with a foreign matter removal operation that removes foreign matter captured on the inner surface of the rotating cylinder from the inner surface. The foreign matter removal operation is performed at least before the draining operation, and the foreign matter in the centrifugal separator unit is discharged by the washing water during the draining operation.

With this, even if a large amount of foreign matter is centrifuged out of the wash water and trapped on the inner surface of the rotating drum, or if the separated foreign matter adheres strongly to the inner surface due to the centrifugal force, the foreign matter can be sufficiently discharged with a specified drainage operation.

The method for controlling a washing machine according to the present embodiment includes a washing tub that contains items to be washed and washing water, a waterway that circulates the washing water outside the washing tub, a pump unit that is provided in the waterway and circulates the washing water through the waterway, a centrifugal separator unit that is provided in the waterway and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least the washing operation including the washing operation and the draining operation. The centrifugal separator unit has a case through which the washing water passes, a rotating cylinder that is rotatably provided within the case and captures foreign matter, and a rotating cylinder motor that drives the rotating cylinder. In the washing operation, the method for controlling a foreign matter separation operation that drives the centrifugal separator unit and the pump unit is performed, and the execution of the foreign matter separation operation is terminated in the middle of the washing operation.

This limits the amount of foreign matter that is separated from the wash water in the centrifuge section and the time that centrifugal force acts on the separated foreign matter, preventing the foreign matter from strongly adhering to the inner surface of the rotating drum.

In addition, any combination of the above components, and any transformation of the present invention into a method, device, system, recording medium, computer program, etc., are also valid aspects of the present invention.

As described above, the washing machine and washing machine control method of the present invention are useful as a washing machine because they can discharge foreign matter separated by centrifugal force from the wash water by a specified drainage operation.

1 Outer tub (washing tub)
4 Rotating drum (washing drum)
17 Drainage channel 18 Drainage valve 19 (19a, 19b) Water channel 20 Centrifugal separation section 21 Case 22 Rotating cylinder 22c Inner peripheral surface (inner surface) of rotating cylinder
23 Rotary barrel motor 24, 37 Pump section 31 Control section 38 Dirt detection section

Claims (4)

A washing tub for containing items to be washed and washing water;
A water channel provided so that the washing water circulates outside the washing tub;
A pump unit provided in the water channel for circulating the washing water through the water channel;
The washing machine includes a centrifugation unit that is provided in the water passage and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least a washing operation including a washing operation and a draining operation,
The centrifugal separation unit includes a case through which the wash water passes, a rotating cylinder rotatably provided in the case and configured to capture the foreign matter, and a rotating cylinder motor configured to rotate the rotating cylinder.
the control unit is provided with a foreign matter separation operation for driving the centrifugal separation unit and the pump unit, and a foreign matter removal operation for removing foreign matter captured on the inner surface of the rotating cylinder from the inner surface, and is configured to execute the foreign matter separation operation for driving the centrifugal separation unit and the pump unit in the cleaning operation, and to terminate execution of the foreign matter separation operation in the middle of the cleaning operation.
washing machine. The foreign matter removal operation is started at least during the washing operation before the draining operation, and the foreign matter in the centrifugal separation unit is discharged by the washing water during the draining operation.
The washing machine according to claim 1. A washing tub for containing items to be washed and washing water;
A water channel provided so that the washing water circulates outside the washing tub;
A pump unit provided in the water channel for circulating the washing water through the water channel;
The washing machine includes a centrifugation unit that is provided in the water passage and separates foreign matter contained in the circulating washing water by centrifugal separation, and a control unit that controls at least a washing operation including a washing operation and a draining operation,
The centrifugal separation unit includes a case through which the wash water passes, a rotating cylinder rotatably provided in the case and configured to capture the foreign matter, and a rotating cylinder motor configured to rotate the rotating cylinder.
The control unit includes a foreign matter separation operation for driving the centrifugal separation unit and the pump unit, and a foreign matter removal operation for removing foreign matter captured on an inner surface of the rotating drum from the inner surface,
In the cleaning operation, the foreign matter separating operation is executed, and the execution of the foreign matter separating operation is terminated during the cleaning operation.
How to control a washing machine. The foreign matter removal operation is started at least during the washing operation before the draining operation, and the foreign matter in the centrifugal separation unit is discharged by the wash water during the draining operation.
A method for controlling a washing machine according to claim 3 .