CN113330154B

CN113330154B - Washing machine

Info

Publication number: CN113330154B
Application number: CN202080009139.6A
Authority: CN
Inventors: 仓挂敏之
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2019-04-09
Filing date: 2020-03-19
Publication date: 2023-02-17
Anticipated expiration: 2040-03-19
Also published as: JP7466075B2; JP2020171392A; CN113330154A; WO2020209030A1

Abstract

The washing machine is provided with: a centrifugal separation part (20) which is arranged on a water path (19) for circulating the washing water in the washing tank and is used for separating foreign matters contained in the washing water flowing in the water path (19); a pump blade (20 k) which is a pump section for circulating the washing water between the washing tank and the centrifugal separation section (20) through a water path (19); and a control unit (21) for controlling the washing operation. The centrifugal separation unit (20) comprises: a housing (20 a) which is connected to the water path (19) in a communicating manner; a rotary drum (20 b) rotatably provided in the housing (20 a); and a rotary drum motor (20 c) that rotates the rotary drum (20 b). The control unit (21) controls the rotary drum motor (20 c) to change the rotation speed of the rotary drum (20 b) so that the speed difference between the rotation speed of the rotary drum (20 b) and the speed of the swirling flow of the washing water in the rotary drum (20 b) is equal to or less than a predetermined value.

Description

Washing machine

Technical Field

The present invention relates to a washing machine for washing fiber products such as clothes.

Background

In a conventional washing machine, it is considered to separate foreign matters such as dirt and lint released from laundry from the washing water during washing to purify the washing water and prevent the separated dirt and the like from being attached to the laundry again (for example, see patent document 1).

Fig. 11 is a schematic configuration diagram of a conventional washing machine. As shown in fig. 11, the washing machine is provided with: a centrifugal separation part 52 for separating foreign matters contained in the washing water in the outer tank 51; and a water path 53 for supplying the washing water before the foreign substances are separated from the outer tub 51 to the centrifugal separation part 52 and supplying the washing water after the foreign substances are separated from the centrifugal separation part 52 into the outer tub 51. The centrifugal separation section 52 includes: a cylindrical housing 54 connected to the water passage 53; a cylindrical rotary drum 55 rotatably provided in the housing 54; and a spin basket motor 56 that drives the spin basket 55 to rotate the spin basket 55.

The washing water flowing in the water path 53 passes in the spin basket 55. That is, the washing water flows into the rotary drum 55 through the washing water inlet 57 provided at the lower portion of the rotary drum 55, and flows out of the rotary drum 55 through the washing water outlet 58 provided at the upper portion of the rotary drum 55. Here, on the washing water outlet 58 side of the rotary drum 55, a pump blade 59 constituting a pump is formed integrally with the rotary drum 55. The pump blade 59 is rotated integrally with the rotary drum 55 by the rotary drum motor 56.

That is, when the rotary drum motor 56 is driven, the rotary drum 55 and the pump blade 59 rotate. Thereby, the washing water in the outer tub 51 circulates so as to pass through the centrifugal separation part 52 provided in the water path 53. Here, the washing water in the outer tub 51 contains foreign matter such as dirt and lint that is released from the laundry by the washing operation. The washing water is passed through the centrifugal separation part 52, whereby foreign matters such as dirt and lint are removed from the washing water, and the washing water is purified. The foreign matter separated from the washing water is held on the inner surface of the spin basket 55 by the centrifugal force generated by the high-speed rotation of the spin basket 55.

In the rinsing step of the conventional washing machine, it is considered that water in the outer tub is circulated by a circulation pump to be injected in a shower-like manner toward laundry in the drum. This promotes the water-containing action in the laundry to improve the rinsing effect (see, for example, patent document 2).

Here, the water level in the outer tub is lowered due to the progress of moisture in the laundry, and the like. As a result, air may enter the circulation pump, and so-called air infiltration may occur. In order to solve this problem, the washing machine described in patent document 2 intermittently drives and stops the circulation pump based on the output of the water level sensor in the outer tub.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2018-183277

Patent document 2: japanese laid-open patent publication No. 2010-46124

Disclosure of Invention

The conventional washing machine shown in fig. 11 circulates the washing water in the outer tub 51 so as to pass through the centrifugal separation unit 52, and removes foreign matter from the washing water to purify the washing water. However, when the water level in the outer tank 51 is lowered by the circulation of the washing water, it is necessary to maintain the washing water stored in the outer tank 51 at a predetermined water level in order to avoid air infiltration. In addition, in the washing machine in which a heater for heating the washing water is provided at the bottom of the outer tub 51, it is necessary to maintain the washing water stored in the outer tub 51 at a predetermined water level in order to avoid overheating or the like due to the heater being exposed from the water surface when the water level is lowered.

Therefore, the pump is driven from the on state to the off state temporarily during the circulation of the washing water, and the water level of the washing water in the outer tub 51 is maintained. It is considered that the washing water is intermittently circulated by intermittently controlling the driving of the pump. However, when the driving of the pump is stopped, the centrifugal force no longer acts on the foreign substances, which are retained on the inner surface of the spin basket 55 and separated from the washing water. As a result, the foreign matter is released from the inner surface of the spin basket 55 and dispersed into the washing water. Moreover, the following problems arise: when the pump is driven to restart the circulation of the washing water, foreign matter is ejected into the washing tub including the outer tub 51 by the circulation flow, and the foreign matter may be attached to the laundry in the washing tub again.

As a countermeasure, for example, when the circulation of the washing water is temporarily stopped, the rotation speed of the spin basket 55 is reduced, and the rotation speed of the spin basket 55 is maintained at or above the rotation speed at which the separated foreign matters are continuously maintained on the inner surface of the spin basket 55. When the circulation of the washing water is restarted, it is conceivable to increase the rotation speed of the spin basket 55 to the same rotation speed as that in the circulation.

However, even in this case, the following problems arise: when the rotation speed of the spin basket 55 is changed, the foreign matter held on the inner surface of the spin basket 55 is separated and dispersed into the washing water, and the foreign matter is ejected into the washing tub together with the washing water. That is, a speed difference is generated between the speed of the swirling flow of the washing water in the spin basket 55 and the speed of the spin basket. This speed difference acts as a shearing force on the foreign matter held on the inner surface of the rotary drum 55, and the foreign matter may be peeled off from the inner surface of the rotary drum 55.

The present disclosure prevents foreign matter separated from washing water from dispersing into the washing water when the rotation speed of a rotary drum is changed. That is, the washing machine can prevent the separated foreign matters from being attached to the washing again, thereby improving the washing effect.

The washing machine of the present disclosure includes: a washing tank for storing the object to be washed and washing water; a water path for circulating washing water in the washing tank; a centrifugal separation part which is arranged on the water path and is used for separating foreign matters contained in the washing water flowing in the water path; a pump section for circulating wash water between the wash tank and the centrifugal separation section through a water path; and a control part for controlling the washing operation. The centrifugal separation part comprises: a housing connected in communication with the water path; a rotary cylinder rotatably provided in the housing; and a rotary drum motor for rotating the rotary drum, wherein the control part controls the rotary drum motor to change the rotation speed of the rotary drum in a mode that the speed difference between the rotation speed of the rotary drum and the speed of the swirling flow of the washing water in the rotary drum is below a specified value.

According to this configuration, the rotation speed of the spin basket can be gradually changed to the rotation speed at which the foreign matter is separated from the washing water, and the speed difference between the rotation speed of the spin basket and the speed at which the swirling flow of the washing water in the spin basket changes with the acceleration and deceleration of the spin basket can be reduced. Therefore, the foreign matter separated from the washing water when the rotation speed of the rotary drum changes can be prevented from dispersing into the washing water. That is, the foreign matter separated can be prevented from adhering to the laundry again by maintaining the state of holding the foreign matter on the inner surface of the rotary drum, thereby improving the cleaning effect.

Drawings

Fig. 1 is a schematic configuration diagram of a washing machine according to a first embodiment of the present disclosure.

Fig. 2 is an enlarged view of a centrifugal separation part of the washing machine in the first embodiment of the present disclosure.

Fig. 3 is a sectional view of 3-3 of fig. 2 in a first embodiment of the present disclosure.

Fig. 4 is a cross-sectional view 4-4 of fig. 2 in a first embodiment of the present disclosure.

Fig. 5 is a block diagram of a washing machine in a first embodiment of the present disclosure.

Fig. 6 is a timing chart showing the operation of the washing machine in the first embodiment of the present disclosure.

Fig. 7 is a conceptual diagram of an action at the D portion of fig. 6 in the first embodiment of the present disclosure.

Fig. 8 is a timing chart showing operations of another example of the washing machine according to the first embodiment of the present disclosure.

Fig. 9 is a schematic configuration diagram of another example of the washing machine in the first embodiment of the present disclosure.

Fig. 10 is a schematic configuration diagram of a washing machine according to a second embodiment of the present disclosure.

Fig. 11 is a schematic configuration diagram of a conventional washing machine.

Detailed Description

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The present disclosure is not limited to the embodiment.

(first embodiment)

Fig. 1 is a schematic configuration diagram of a washing machine according to a first embodiment of the present disclosure. As shown in fig. 1, the washing machine includes an outer tub 1 and a spin tub 4 rotatably provided in the outer tub 1 as a washing tub. The outer tub 1 is formed in a bottomed tubular shape, and is elastically supported by a plurality of suspension mechanisms 3 inside a frame 2 constituting an outer frame of the washing machine. The rotary tub 4 is formed in a bottomed tubular shape and is provided in the outer tub 1. An opening 6 for a user to put in and take out laundry 5 such as clothes as an object to be washed is provided on the front surface side (left side in fig. 1) of the outer tub 1 and the rotary tub 4.

The rotary tub 4 is provided to be rotatable around a rotary shaft 7. A plurality of (e.g., 3) protrusions 8 protruding inward are provided on the peripheral wall surface 4a of the rotary tub 4. The peripheral wall surface 4a is provided with a plurality of small holes 9, and the inside and outside of the rotary tub 4 in the outer tub 1 communicate with each other through the small holes 9. The outer tub 1, the rotation tub 4, and the rotation shaft 7 are disposed at an angle θ (for example, 20 °) forward and upward with respect to the horizontal.

The rotary tub 4 is configured to be rotatable forward and backward by a motor 10 provided at the rear portion of the outer tub 1. The motor 10 is formed of, for example, a brushless dc motor, and the rotation speed can be freely changed by inverter control of a control unit 21 described later.

The opening 1a of the outer tub 1 and the opening 2a of the housing 2 are formed to face the opening 6 of the rotary tub 4. A door 11 for opening and closing the opening 2a is provided on the front surface of the housing 2. The opening 1a and the opening 2a are connected to each other by a bellows-shaped seal 12 which can expand and contract freely, so as to ensure an airtight structure.

A water supply port 13 for supplying washing water is provided at an upper portion of the rear surface of the housing 2. The water supply port 13 is connected to a tap 13a of a tap water pipe. Thus, the washing water is tap water supplied from water supply port 13. A water supply valve 14 and a detergent box 15 are provided downstream of the water supply port 13. Here, controller 21 drives water supply valve 14 to open and close water supply valve 14, thereby stopping water supply and water supply. Further, as indicated by arrow a, the detergent box 15 is configured such that the detergent input portion 15a can be pulled out to the near side from the detergent box 15. This allows the user to easily put detergent into the detergent box 15.

As indicated by arrow B, the washing water supplied from the water supply port 13 flows into the detergent box 15. The washing water flows into the outer tub 1 while dissolving the detergent put into the detergent box 15. A drain port 16 for draining the washing water is provided at the bottom of the outer tub 1. Here, the drain port 16 is connected to the drain passage 17. Further, a drain valve 18 is provided in the drain path 17. Therefore, the control unit 21 drives the drain valve 18 to open and close the drain valve 18, thereby accumulating or discharging the washing water in the outer tub 1.

One end of the water path 19 is connected to the water discharge path 17, and the other end is provided with a discharge port 31 provided so as to face an upper portion of the opening 6 provided on the front surface side of the rotary tub 4. The washing water is discharged from discharge port 31 into rotary tub 4 to form a circulation path. The washing water is sprayed in a shower shape so that the washing water falls from a position higher than the water level in the outer tub 1 to a wide range of the laundry 5 in the rotary tub 4.

The water path 19 is connected to a centrifugal separation part 20 provided below the outer tub 1. The water path 19 includes: a water path 19a for allowing the washing water in the outer tub 1 to flow into the centrifugal separation part 20; and a water path 19b for allowing the washing water having passed through the centrifugal separation part 20 to flow into the rotary tub 4, wherein a discharge port 31 is provided at an outlet of the water path 19 b.

When the washing water flowing through the water passage 19 from the drain port 16 through the drain passage 17 passes through the centrifugal separation unit 20, foreign substances contained in the washing water are separated as described below. The foreign matter includes stains and lint released from the laundry, and water softeners contained in detergents dissolved in the washing water.

The water passage 19 is provided with an on-off valve 32, and the on-off valve 32 is an adjustment portion for controlling the flow of the washing water. The control unit 21 controls the opening and closing of the open/close valve 32. The opening/closing valve 32 is constituted by, for example, an electromagnetic valve.

Fig. 2 is an enlarged view of the centrifugal separation part of the washing machine in the present embodiment. Fig. 3 is a cross-sectional view of 3-3 of fig. 2. Fig. 4 is a cross-sectional view 4-4 of fig. 2.

The centrifugal separation section 20 includes: a housing 20a connected to the

water paths

19a and 19 b; a hollow rotary cylinder 20b rotatably provided in the housing 20 a; and a rotary drum motor 20c which is a driving unit for rotating the rotary drum 20b.

The rotary cylinder 20b includes: a cylindrical inner peripheral surface 20d; a washing water inlet 20e for washing water to flow from the water path 19a into the rotary drum 20 b; and a washing water outlet 20f for the washing water to flow out from the spin basket 20b to the water path 19 b. Here, the rotation shaft 20g of the rotary cylinder 20b is set in the vertical direction. Therefore, the washing water in the outer tub 1 flows into the rotary tub 20b through the water passage 19a from the washing water inlet 20e provided at the center of the bottom surface of the rotary tub 20b. Thereafter, since the washing water inlet 20e is positioned below the washing water outlet 20f, the washing water passing through the centrifugal separation part 20 flows upward from below in the spin basket 20b.

At this time, the control unit 21 drives the rotary drum motor 20c to rotate the rotary drum 20b at, for example, about 3500rpm. Thereby, the washing water flowing into the rotary tub 20b swirls in the rotary tub 20b, and a high-speed swirling flow is generated. The washing water flowing into the rotary drum 20b flows out through a washing water outlet 20f provided at an upper portion of the rotary drum 20b. In this manner, the centrifugal separation unit 20 is configured to cause the passing washing water to flow upward from below in the direction of the rotation shaft 20g in the rotary drum 20b. Also, the washing water receives a centrifugal force due to the rotation of the spin basket 20b while passing through the spin basket 20b. Thereby, the foreign matters contained in the washing water are centrifugally separated, go to the inner peripheral surface 20d of the spin basket 20b, and are collected on the inner peripheral surface 20d.

Here, the diameter of the inner circumferential surface 20d around the rotation shaft 20g of the spin basket 20b is configured to be larger than the maximum diameter of the washing water inlet 20e and the washing water outlet 20 f. Accordingly, the centrifugal force applied to the washing water is stronger as the distance from the center of the rotary drum 20b as the rotary shaft 20g is closer to the inner circumferential surface 20d. Therefore, the foreign matters separated from the washing water passing through the spin basket 20b by the centrifugal force are held by the inner peripheral surface 20d by the stronger centrifugal force as they approach the inner peripheral surface 20d. Thereby, the foreign matters separated by the centrifugal force are sucked into the circulating flow of the washing water passing through the spin basket 20b, and are held by the centrifugal force at the inner circumferential surface 20d. That is, the re-adhesion of stains to the laundry 5 can be prevented, and the cleaning power can be improved.

In the centrifugal separation part 20, a swirling flow generating part 20h is provided on the inflow side of the washing water passing through the casing 20 a. The swirling flow generating portion 20h is formed integrally with the housing 20 a. As shown in fig. 4, the swirling flow generating portion 20h is connected to the water passage 19a at a position offset to the side of the swirling flow generating portion 20h. Further, in the centrifugal separation section 20, a pump chamber 20i is provided on the outflow side of the washing water passing through the casing 20 a. As shown in fig. 3, a pump vane 20k (pump section) formed integrally with the rotary cylinder 20b is disposed in the pump chamber 20i, and is connected to the water passage 19b at a position offset to the side of the pump chamber 20i.

The pump blade 20k rotates together with the rotary drum 20b by driving of the rotary drum motor 20c, thereby generating a pump action. The washing water in the outer tub 1 circulates as indicated by arrow C (see fig. 1) through the centrifugal separation unit 20 from a water passage 19 formed at a lower portion outside the outer tub 1 by the pump action. At this time, the flow rate of the washing water flowing through the water path 19 can be set according to the pump capacity of the pump section. The pump capacity can be set in consideration of the number of the pump blades 20k (4 in the present embodiment), the shape, and the like, in addition to the rotation speed of the pump blades 20 k.

According to the above structure, the washing water flows through the water path 19 and circulates between the centrifugal separation part 20 and the outer tub 1. When the flow velocity of the circulating flow when the washing water passes through the centrifugal separation part 20 is V1 and the flow velocity of the swirling flow when the washing water swirls in the rotary drum 20b is V2, V2> V1 is set so that the flow velocity V2 of the swirling flow is higher than the flow velocity V1 of the circulating flow.

The control unit 21 is provided in a lower portion of the housing 2 as shown in fig. 1. Fig. 5 is a block diagram of the washing machine according to the present embodiment. The washing machine is provided with: a cloth amount detecting unit 22 for detecting the amount of the laundry 5 put into the rotary tub 4; a water amount detection unit 23 for detecting the amount of the washing water supplied into the outer tub 1; and a rotation detecting unit 24 for detecting the rotational driving of the rotary tub 4. The control unit 21 receives an output from the cloth amount detection unit 22, an output from the water amount detection unit 23, and an output from the rotation detection unit 24.

Further, the control unit 21 controls the driving of the motor 10, the water supply valve 14, the drain valve 18, the rotary drum motor 20c, and the on-off valve 32 based on the washing course set by the user through the operation display unit 25, and performs the washing operation. Here, the washing operation includes a washing step, a rinsing step, and a dewatering step.

The operation and action of the washing machine configured as described above will be described below. First, the user opens the door 11 provided on the front surface of the housing 2, and puts the laundry 5 into the rotary tub 4 through the opening 6. Next, the user turns on a power switch (not shown) of the operation display unit 25 provided on the upper portion of the front surface of the housing 2, and operates a start switch (not shown) to start the washing operation.

In response to the start of the washing operation, the controller 21 first detects the amount of the laundry 5 put into the rotary tub 4 by the cloth amount detector 22. The cloth amount detector 22 detects the amount of the laundry 5 based on the amount of torque applied to the motor 10 when the rotary tub 4 is rotated. The cloth amount detector 22 may detect the amount of the laundry 5 based on a current value of the motor 10 when the rotary tub 4 is rotated. The control unit 21 sets the time and the amount of the washing water for each of the above-described washing step, rinsing step, and spin-drying step, based on the amount of the laundry 5 detected by the cloth amount detection unit 22. At the same time, the control unit 21 causes the operation display unit 25 to display the amount of the detergent predetermined according to the amount of the laundry 5.

First, a cleaning process in the cleaning operation will be described. The user pulls out the detergent input portion 15a from the detergent box 15 and inputs detergent according to the approximate target of the amount of detergent displayed on the operation display portion 25. After that, the user moves the detergent input portion 15a into the detergent box 15.

After the completion of the input of the detergent, control unit 21 opens water supply valve 14. When the water supply valve 14 is opened, the washing water flows from the water supply port 13 into the detergent box 15 as indicated by arrow B. Thereafter, the washing water is supplied to the outer tub 1 while dissolving the detergent in the detergent box 15. The washing water accumulated in the bottom of the outer tub 1 flows into the rotary tub 4 through the small holes 9.

Here, the water amount detector 23 detects the washing water accumulated in the outer tub 1. When water amount detector 23 detects that the amount of washing water stored in outer tub 1 reaches a predetermined amount, controller 21 closes water supply valve 14 to complete water supply. Here, the predetermined amount is an amount of washing water preset in accordance with the amount of the laundry 5.

When the water supply is completed, the control part 21 drives the motor 10 to rotate the rotary tub 4. By the rotation of the rotary tub 4, the laundry 5 is lifted in the rotation direction by the protrusions 8 in the rotary tub 4 and falls from above. The dropped laundry 5 hits the laundry 5 remaining on the bottom surface of the spin basket 4 or the bottom of the spin basket 4. In this manner, the cleaning step is performed by the chemical force generated by the detergent and the mechanical force generated by the impact. The rotary tub 4 is driven to rotate in the forward and reverse directions at predetermined intervals to beat and wash the laundry 5. The rotation speed of the rotary tub 4 is, for example, 45rpm.

Next, a rinsing step of the washing operation will be described. After the washing step is performed for a predetermined time, the controller 21 opens the drain valve 18 to discharge the washing water in the outer tub 1 to the outside of the washing machine. After the completion of the water discharge, controller 21 supplies a predetermined amount of washing water into outer tub 1 and rotates rotary tub 4 in the same manner as in the cleaning step. Thereby, the rinsing operation for the laundry 5 is performed. At this time, the detergent in the detergent box 15 is completely used up in the washing process. Therefore, the washing water does not contain a detergent during the rinsing operation.

Finally, the dehydration step in the washing operation will be described. After the rinsing step, controller 21 opens drain valve 18 to discharge the washing water in outer tub 1 to the outside of housing 2. Then, the control unit 21 rotates the rotary tub 4 at a high speed by driving the motor 10, thereby performing dehydration on the laundry 5 in the rotary tub 4. When the dehydration step is completed, the control unit 21 ends the washing operation.

Next, the operation of the centrifugal separation unit 20 for purifying the washing water will be described. In the cleaning step, the washing water in the outer tub 1 contains various foreign matters such as dirt of the laundry. For example, the stain material may be a material heavier than water, such as sand, fiber waste, hair, and keratin stain. In addition, there are substances which are lighter than water, such as oil and fat components typified by sebum, but adhere to materials heavier than water, such as strings.

In the washing step, the control unit 21 drives the rotary drum motor 20c to circulate the washing water in the outer tub 1 to the centrifugal separation unit 20. That is, the rotary bowl 20b and the pump blade 20k are rotated by driving the rotary bowl motor 20c. The washing water in the outer tub 1 flows into the swirling flow generating portion 20h through the water passage 19a by the pump action of the rotating pump blade 20 k. Here, the water passage 19a communicates with the swirling flow generating portion 20h at a position offset to the side of the swirling flow generating portion 20h.

After the washing water flows in from the water passage 19a, a swirling component is given to the washing water by the swirling flow generating portion 20h, and the washing water flows into the rotary tub 20b from the washing water inlet 20 e. At this time, since the spin basket 20b is rotated by the spin basket motor 20c, the washing water introduced into the spin basket 20b becomes a high-speed swirling flow in the spin basket 20b.

The washing water passes through the inside of the spin basket 20b after flowing in from the washing water inlet 20e and flows out from the washing water outlet 20 f. At this time, a strong centrifugal force generated by the high-speed swirling flow in the spin basket 20b acts on foreign substances contained in the washing water and having a heavier specific gravity than the washing water. As a result, the foreign matter is directed toward the inner peripheral surface 20d of the rotary cylinder 20b. In this way, the dirt and substance specific to the laundry contained in the washing water is separated from the washing water and removed from the washing water.

At this time, the dirt separated from the washing water by the centrifugal force and going toward the inner circumferential surface 20d of the spin basket 20b is not sucked into the circulating flow passing through the spin basket 20b and is not returned to the circulating flow. That is, the washing water passing through the inside of the spin basket 20b has a region located outside the circulating flow passing through the vicinity of the rotation shaft 20g of the spin basket 20b and located inside the inner circumferential surface 20d of the spin basket 20b. However, a strong centrifugal force acts from the circulating flow portion toward the inner peripheral surface 20d of the spin basket 20b. In addition, the washing water inlet 20e and the washing water outlet 20f of the spin basket 20b are occupied by the circulation flow.

As described above, the washing water is separated from the dirt in the rotary drum 20b, and flows out from the washing water outlet 20f to the pump chamber 20i. Thereafter, the washing water is discharged from the pump chamber 20i into the rotary tub 4 through the water passage 19b and the discharge port 31 by the pump action of the pump blade 20 k.

As described above, the washing water in the outer tub 1 circulates between the outer tub 1 and the centrifugal separation unit 20 through the water path 19 by the pump function provided in the centrifugal separation unit 20. This can purify the washing water and prevent the separated contaminants from adhering to the laundry 5 again, thereby improving the washing performance of the washing machine.

In the spin basket 20b of the centrifugal separation unit 20, the washing water passes through from the bottom to the top while swirling. At this time, bubbles contained in the washing water and bubbles in the water path 19, which are sometimes generated by the detergent, enter the spin basket 20b. In this case, the bubbles lighter than water are collected in the center portion of the spin basket 20b by the swirling flow. In addition, the action of the upward floating action and the action of the washing water flowing from the bottom to the top are matched with each other, so that the bubbles are easily discharged from the washing water outlet 20f to the outside of the spin basket 20b.

This can prevent imbalance in the distribution of water and air bubbles in the rotary drum 20b, which occurs when air bubbles lighter than water are retained in the rotary drum 20b, and can minimize fluctuations in torque required to rotate the rotary drum 20b. Further, since the rotational speed of the rotary drum 20b can be prevented from varying due to torque variation and the rotational vibration of the rotary drum 20b due to imbalance can be prevented, the rotary drum 20b can be made larger. Further, since the flow in the rotary drum 20b is not disturbed due to the retention of the air bubbles lighter than water in the rotary drum 20b, the foreign matter that has been separated from the washing water and held on the inner peripheral surface 20d of the rotary drum 20b can be prevented from being dispersed into the washing water.

Further, the foreign matter collected on the inner peripheral surface 20d of the spin basket 20b is discharged to the outside of the housing 2 when the washing water is discharged. That is, the controller 21 opens the drain valve 18 to discharge the washing water in the outer tub 1 to the outside of the machine. At this time, the washing water in the water path 19 flows in the opposite direction to the circulation. That is, the washing water flows from the water path 19b to the water path 19a in the centrifugal separation part 20. The foreign matter collected on the inner peripheral surface 20d is discharged to the outside of the housing 2 through the drain valve 18 with the flow of the washing water. This eliminates the need for a configuration in which a part of the washing water to be purified is discarded during the operation of the centrifugal separation.

Next, circulation control of the washing water in the washing step and drive control of the rotary drum motor 20c in the centrifugal separation unit 20, which are performed by the control unit 21, will be described. Fig. 6 is a timing chart showing the operation of the washing machine in the present embodiment. As shown in fig. 6, control unit 21 opens water supply valve 14 when the cleaning process is started (time T0). Thereby, the washing water is supplied into the outer tub 1, and the water level in the outer tub 1 is increased.

The control unit 21 detects the water level by the water level detecting unit 23. When water level detector 23 detects that the water level in outer tub 1 has reached predetermined amount L3, controller 21 closes water supply valve 14 (time T1). Here, the predetermined amount L3 is a water level set according to the amount of the laundry 5. The control unit 21 opens the water passage 19 by opening the on-off valve 32 at substantially the same timing as the closing timing of the water supply valve 14, and drives the rotary drum motor 20c.

The control unit 21 drives the rotary drum motor 20c to rotate the rotary drum 20b at the rotation speed Hi. Here, the rotation speed Hi is a rated rotation speed at which the dirt can be centrifugally separated from the washing water in the centrifugal separation portion 20, and is, for example, 3500rpm. As described above, the control unit 21 drives the rotary drum motor 20c to rotate the pump blade 20k integrally provided with the rotary drum 20b, thereby generating a pump action. Thereby, the washing water circulates between the inside of the outer tub 1 and the centrifugal separation part 20 through the water path 19. The centrifugal separator 20 separates foreign matters from the circulating washing water.

The washing water is circulated and discharged from the discharge port 31 into the rotary tub 4. A part of the sprayed washing water is contained in the laundry 5, and the water level in the outer tub 1 is lowered. When the water level in the outer tank 1 is detected to be the first water level L1 by the water amount detector 23, the controller 21 closes the on-off valve 32 to close the water path 19 (time T2). Thereby, the circulation of the washing water flowing in the water path 19 is stopped. Here, the first water level L1 is a water level at which air infiltration or the like does not occur in the pump chamber 20i due to the pump blade 20 k. The first water level L1 is a water level at which a heater (not shown) is not exposed from the water surface when the heater is provided at the bottom of the outer tub 1.

The controller 21 closes the water passage 19 to stop the ejection of the washing water from the ejection port 31 and the outflow of the washing water from the drain port 16 to the water passage 19. Thereby, the circulation of the washing water is stopped and the water level does not drop below the first water level. Therefore, air infiltration due to a drop in the water level in the outer tub 1 can be prevented. In addition, in the case where the heater is provided at the bottom of the outer tub 1, overheating or the like caused by the heater being exposed from the water surface due to the water level in the outer tub 1 falling can be prevented.

Next, the control section 21 controls the rotary drum motor 20c to decelerate the rotary drum 20b from the rotation speed Hi to the rotation speed L o at substantially the same timing as the timing of closing the opening and closing valve 32. At this time, the control unit 21 controls the spin basket motor 20c not by a rapid change in the rotation speed such as tap switching but by a smooth or fine stepwise change in the rotation speed by an inverter or the like. Here, the rotation speed L o is a rotation speed at which the foreign matters separated by the centrifugal separation part 20 are continuously held on the inner circumferential surface 20d of the spin basket 20b, and is, for example, 800rpm. This can maintain the state where the foreign matter is held on the inner peripheral surface 20d of the rotary drum 20b, and prevent the separated foreign matter from being dispersed into the washing water.

Specifically, the control unit 21 controls the rotary drum motor 20c to gradually reduce the rotation speed of the rotary drum 20b. Fig. 7 is a schematic diagram of an action at a portion D of fig. 6.

As shown in fig. 7, when the energization of the rotary drum motor 20c is turned off, the rotary drum 20b is generally decelerated rapidly as indicated by a dashed line S1. On the other hand, the speed of the swirling flow of the washing water flowing along with the rotation of the spin basket 20b is decreased more slowly than the spin basket 20b by inertia as shown by the broken line W1. Therefore, a speed difference is generated between the rapid speed decrease of the spin basket 20b and the speed decrease of the swirling flow of the washing water. This speed difference acts as a shearing force, and there is a possibility that foreign matter held on the inner peripheral surface 20d of the rotary cylinder 20b is peeled off.

Therefore, the control unit 21 controls the driving of the rotary drum motor 20c to gradually reduce the change in the rotation speed as indicated by the solid line Y1. This allows the deceleration of the spin basket 20b to change from the dashed line S1 in the direction of the arrow, and to follow and approach the descending speed of the washing water.

That is, the expansion of the speed difference between the swirling flow speed of the washing water and the rotation speed of the spin basket 20b is suppressed. That is, it is preferable that the deceleration of the spin basket 20b substantially coincides with the decrease in the speed of the swirling flow of the washing water. This can weaken the shearing force acting on the foreign matter held on the inner peripheral surface 20d of the rotary cylinder 20b.

Specifically, the control unit 21 changes the rotation speed of the spin basket 20b so that the speed difference between the rotation speed of the spin basket 20b and the speed of the swirling flow of the washing water in the spin basket 20b is equal to or less than a predetermined value. Here, the predetermined value is a speed difference that can maintain a state in which the foreign matter separated by the centrifugal separation portion 20 is held on the inner circumferential surface 20d of the rotary cylinder 20b. Therefore, the state of the foreign matter held by the inner peripheral surface 20d of the rotary drum 20b can be maintained, and the separated foreign matter can be prevented from being dispersed into the washing water.

Next, after the water level in the outer tank 1 has dropped to the first water level L1, the controller 21 closes the on-off valve 32 to close the water path 19. Thereby, the washing water contained in the laundry 5 flows out into the outer tub 1, and the water level in the outer tub 1 rises again. When the water level in the outer tank 1 is detected by the water amount detector 23 to be the second water level L2, the controller 21 opens the water path 19 by opening and closing the valve 32 (time T3). Here, the second water level L2 is a water level higher than the first water level L1 by a predetermined amount.

Next, the control unit 21 controls the rotary drum motor 20c to accelerate the rotary drum 20b from the rotational speed Lo to the rotational speed Hi at substantially the same timing as the opening/closing valve 32 is opened. At this time, the control unit 21 controls the rotary tub motor 20c not by a rapid change in the rotation speed such as tap switching, but by a smooth or fine stepwise change in the rotation speed by an inverter or the like. As a result, as described above, the washing water in the outer tub 1 flows through the water path 19 by the pump function provided in the centrifugal separation unit 20, and the circulation between the inside of the outer tub 1 and the centrifugal separation unit 20 is restarted. The second water level L2 is set to a constant water level that the laundry 5 can contain during the period from the second water level L2 to the first water level L1 due to the circulation of the washing water, but is not limited thereto.

Specifically, the control unit 21 controls the rotary drum motor 20c to gradually accelerate the rotation speed of the rotary drum 20b.

Generally, when the current to the rotary drum motor 20c is turned on, the rotary drum 20b is rapidly accelerated as indicated by the dashed dotted line S2. On the other hand, the speed of the swirling flow of the washing water flowing along with the rotation of the spin basket 20b gradually rises as indicated by the broken line W2 so as to be slower than the spin basket 20b. Therefore, a speed difference is generated between the rapid speed increase of the spin basket 20b and the speed increase of the swirling flow of the washing water. This speed difference acts as a shearing force, and there is a possibility that foreign matter held on the inner peripheral surface 20d of the rotary cylinder 20b is peeled off.

Therefore, the control unit 21 controls the rotary drum motor 20c to gradually accelerate the change in the rotation speed as indicated by the solid line Y2. This makes it possible to change the acceleration of the spin basket 20b from the dashed line S2 in the direction of the arrow, and to follow and approach the rising speed of the washing water.

That is, the expansion of the speed difference between the swirling flow speed of the washing water and the rotation speed of the spin basket 20b is suppressed. That is, it is preferable that the acceleration of the spin basket 20b substantially coincides with the speed increase of the swirling flow of the washing water. This can weaken the shearing force acting on the foreign matter held on the inner peripheral surface 20d of the rotary cylinder 20b.

As described above, the controller 21 repeats the above-described operation in accordance with the change in the water level in the outer tub 1 in the cleaning step. That is, if the water level in the outer tank 1 decreases to reach the first water level L1, the controller 21 closes the on-off valve 32 to close the water path 19. Thereby, the circulation of the washing water is stopped (time T2, T4, T6). Then, the control section 21 controls the spin basket motor 20c to decelerate the spin basket 20b from the rotation speed Hi to the rotation speed L o at substantially the same timing as the time when the open/close valve 32 is closed. At this time, the controller 21 sets the speed difference between the rotation speed of the rotary drum 20b and the speed of the swirling flow of the washing water in the rotary drum 20b to a predetermined value or less.

Further, if the water level in the outer tank 1 rises to reach the second water level L2, the control unit 21 opens the water path 19 by opening the on-off valve 32. Thereby, the circulation of the washing water is started again (time T3, T5, T7). Then, the control section 21 controls the spin basket motor 20c to accelerate the spin basket 20b from the rotation speed L o to the rotation speed Hi at substantially the same timing as the timing at which the open-close valve 32 is opened. At this time, the controller 21 sets the speed difference between the rotation speed of the rotary drum 20b and the speed of the swirling flow of the washing water in the rotary drum 20b to a predetermined value or less.

Here, the predetermined value is a speed difference that can maintain a state in which the foreign matter separated by the centrifugal separation portion is held on the inner circumferential surface 20d of the rotary drum 20b. This makes it possible to separate foreign matter in the washing water and to cause the washing water to fall from the spout 31 to the laundry 5 to promote the washing water to be contained in the laundry 5, thereby improving the washing effect. In addition, the water level of the washing water in the washing tub and the water level of the laundry in the washing tub can be optimized.

Fig. 8 is a timing chart showing the operation of another example in the present embodiment. The control part 21 drives the spin basket motor 20c to accelerate the spin basket 20b from the rotation speed L o to the rotation speed Hi when the circulation of the washing water is started again. The control unit 21 opens the on-off valve 32 at substantially the same timing as the rotational speed Hi of the rotary drum 20b.

Specifically, when the control unit 21 closes the on-off valve 32, the washing water contained in the laundry 5 flows into the outer tub 1, and the water level in the outer tub 1 rises again. When the water level detector 23 detects that the water level in the outer tub 1 has reached the second water level L2, the controller 21 controls the spin basket motor 20c to accelerate the spin basket 20b from the rotational speed Lo (time T3 a).

Next, the control unit 21 opens the on-off valve 32 at substantially the same timing as the timing at which the rotary drum 20b rises to the rotation speed Hi (time T3 b). Accordingly, when the circulation of the washing water is resumed, the spin basket 20b rotates at the rotation speed Hi, and thus the foreign substances can be efficiently separated.

Fig. 9 is a schematic configuration diagram of another example of the washing machine in the present embodiment. As shown in fig. 9, an adjustment valve 33 as an adjustment part is provided at a position on the upstream side of the centrifugal separation part 20 of the water passage 19 in place of the on-off valve 32. The adjustment valve 33 can adjust the amount of the passing washing water in a plurality of stages or continuously. The controller 21 controls the regulating valve 33 to stop the washing water flowing through the water passage 19 and to regulate the water amount.

The controller 21 can set the amount of the washing water flowing through and circulating through the water passage 19 by adjusting the valve 33, for example, according to the amount of the laundry 5. The cloth amount detecting unit 22 detects the amount of the laundry 5. Therefore, the controller 21 can control the adjustment valve 33 so that the amount of the washing water flowing through the water passage 19 becomes a water amount set in accordance with the cloth amount detected by the cloth amount detector 22.

When the water amount detector 23 detects that the washing water in the outer tub 1 has reached the first water level L1, the controller 21 controls the regulating valve 33 to stop the flow of the washing water. Alternatively, the amount of circulating water may be reduced to flow a small amount of washing water. In this case, the amount of circulating water may be set to be such that the washing water in the outer tub 1 is lower than the first water level L1.

When the water amount detector 23 detects that the level of the washing water in the outer tub 1 is at the second water level L2, the controller 21 controls the control valve 33 to start the flow of the washing water. Alternatively, the amount of circulating water may be increased.

The control of the spin basket motor 20c when the rotation speed of the spin basket 20b is accelerated as described above may be performed at the start of the washing step (time T1) in addition to the restart of the circulation of the washing water in the washing step or the increase of the amount of circulating water. That is, it is effective when the rotation speed of the rotary drum 20b is increased. This prevents foreign matter deposited on the inner peripheral surface 20d of the spin basket 20b from dispersing into the washing water even immediately after the start of the washing operation.

The control unit 21 can perform the above-described operation of separating foreign matters contained in the washing water and the above-described operation of dispersing the washing water into the laundry, in the rinsing step as well as in the cleaning step. In particular, in the rinsing step, zeolite having a specific gravity higher than that of water in the cleaning assistant contained in the detergent can be separated by the centrifugal separation part 20, and thus the rinsing performance can be improved. The controller 21 can control the spin basket motor 20c when the rotation speed of the spin basket 20b changes, thereby preventing the foreign matter separated from the washing water from being dispersed into the washing water. That is, the separated foreign matter can be prevented from adhering to the laundry 5 again, and the rinsing performance can be improved.

As described above, the washing machine of the present embodiment includes: a washing tank for containing the object to be washed and washing water, comprising an outer tank 1 and a rotary tank 4; a water path 19 for circulating the washing water in the washing tank; a centrifugal separation part 20 provided in the water path 19 for separating foreign matters contained in the washing water flowing through the water path 19; a pump blade 20k for circulating the washing water between the washing tank and the centrifugal separation part 20 through the water path 19; and a control unit 21 for controlling the washing operation. The centrifugal separation section 20 includes: a housing 20a connected to the water path 19; a rotary drum 20b rotatably provided in the housing 20 a; and a spin basket motor 20c for rotating the spin basket 20b. The controller 21 controls the spin basket motor 20c to change the rotation speed of the spin basket 20b so that a speed difference between the rotation speed of the spin basket 20b and the speed of the swirling flow of the washing water in the spin basket 20b is equal to or less than a predetermined value.

According to this configuration, the rotational speed of the spin basket 20b can be changed slowly, and the speed difference between the rotational speed of the spin basket 20b and the speed of the swirling flow of the washing water in the spin basket 20b, which changes with acceleration and deceleration of the spin basket 20b, can be reduced. Therefore, it is possible to prevent the foreign substances separated from the washing water from being dispersed into the washing water when the rotation speed of the spin basket 20b is changed. That is, the state in which the foreign matter is held on the inner peripheral surface 20d of the rotary cylinder 20b is maintained. Therefore, the separated foreign matter can be prevented from adhering to the laundry 5 again, and the cleaning effect can be improved. In addition, the circulation of the washing water can promote the washing water to be contained in the laundry 5, thereby further improving the washing effect.

The predetermined value of the speed difference is a value that can maintain the state in which the foreign matter separated by the centrifugal separation section 20 is held on the inner circumferential surface 20d of the rotary drum 20b.

With this configuration, the foreign matter can be kept on the inner peripheral surface 20d of the rotary drum while the rotation speed of the rotary drum 20b is changed. In other words, the foreign matter separated from the washing water can be prevented from dispersing into the washing water.

The water path 19 is provided with an adjustment unit (an on-off valve 32 or an adjustment valve 33) for controlling the flow of the washing water, and the control unit 21 controls the circulation of the washing water by the adjustment unit.

According to this configuration, the water level of the laundry 5 in the washing tub including the outer tub 1 and the rotary tub 4 and the water level of the washing water in the washing tub can be optimized.

The pump section includes a pump blade 20k, the pump blade 20k is provided on the outflow side of the rotary drum 20b through which the washing water passes, and the pump blade 20k rotates integrally with the rotary drum 20. The pump blade 20k is configured to be rotated together with the rotary tub 20b by the rotary tub motor 20c, and to circulate the washing water between the centrifugal separation unit 20 and the washing tub through the water path 19.

According to this configuration, the washing water in the washing tank including the outer tank 1 and the rotary tank 4 is circulated through the centrifugal separation unit 20 by the rotation of the rotary drum 20b. The centrifugal separation unit 20 can be provided with a pump function for circulating the washing water by a simple structure.

The controller 21 controls the spin basket motor 20c to rotate the spin basket 20b at a rotation speed Lo (second rotation speed) at which the foreign matters separated by the centrifugal separator 20 can be held on the inner circumferential surface 20d of the spin basket 20b when the circulation of the washing water is stopped or the amount of the circulating water is reduced.

According to this configuration, the state in which the foreign matter centrifugally separated from the washing water is held on the inner peripheral surface 20d of the spin basket 20b can be maintained when the circulation of the washing water is stopped or when the amount of circulating water is reduced.

Further, a water amount detector 23 for detecting the water level of the washing water in the washing tub is provided, and when the water amount detector 23 detects that the washing water in the washing tub becomes the first water level L1 during circulation of the washing water, the controller 21 stops or reduces the flow of the washing water in the water passage 19 by an adjusting unit (an on-off valve 32 or an adjusting valve 33).

According to this structure, the washing water in the washing tank can be maintained at a predetermined water level. Thus, air infiltration due to a drop in water level can be prevented. In addition, when the heater is provided at the bottom of the washing tank, overheating and the like caused by the heater being exposed from the water surface can be prevented.

When the water quantity detector 23 detects that the washing water in the washing tub has reached the second water level L2 when the circulation of the washing water in the washing tub is stopped, the controller 21 starts or increases the flow of the washing water in the water passage 19 by the adjustment unit (the on-off valve 32 or the adjustment valve 33).

According to this configuration, the washing water in the washing tub can be maintained at a predetermined water level.

In the present embodiment, the pump chamber 20i is provided on the outflow side of the housing 20a, but the present invention is not limited to this. For example, the pump chamber 20i may be provided on the inflow side of the housing 20a, and the washing water may be configured to flow into the rotary cylinder 20b from the pump chamber 20i in a swirling manner.

(second embodiment)

Fig. 10 is a schematic configuration diagram of a washing machine according to a second embodiment of the present disclosure. In the present embodiment, the pump 34 as the pump section is provided in the water path 19 independently of the centrifugal separation section 20. The control unit 21 controls the circulation of the washing water by the pump 34 as a pump unit. Therefore, unlike the first embodiment, the opening and closing valve 32 is not required. Other structures are the same as those of the first embodiment, the same structures are denoted by the same reference numerals, and the detailed description refers to the description of the first embodiment.

The pump 34 as a pumping section is provided at a position on the upstream side of the centrifugal separation section 20 of the water path 19. The washing water in the outer tub 1 flows through the water path 19 by driving of the pump 34, and circulates through the centrifugal separation part 20.

The control section 21 controls the driving and the driving stop of the pump 34. The washing water is circulated by driving of the pump 34. Thereby, the washing water is ejected from the ejection port 31 into the rotary tub 4. As a result of a part of the sprayed washing water being contained in the laundry 5, the water level in the outer tub 1 is lowered. The control unit 21 detects the water level in the outer tub 1 by the water amount detecting unit 23. When the water level in the outer tub 1 is detected to be the first water level L1 by the water amount detector 23, the controller 21 stops the driving of the pump 34.

Thereby, the circulation of the washing water is stopped, and the washing water contained in the laundry 5 flows out into the outer tub 1, so that the water level in the outer tub 1 rises again. When the water level in the outer tub 1 is detected to become the second water level L2 by the water amount detecting part 23, the control part 21 drives the pump 34. Thereby, the circulation of the washing water is started again. In this manner, the controller 21 controls the driving of the pump 34 so that the water level in the outer tub 1 is maintained at the first water level L1 or more.

When it is detected that the washing water in outer tub 1 reaches first water level L1, controller 21 may drive pump 34 to flow a small amount of washing water. In this case, the amount of the washing water in the outer tub 1 may be not less than the first water level L1. When it is detected that the washing water in the outer tub 1 reaches the second water level L2, the controller 21 may drive the pump 34 to increase the circulation water amount.

As described above, in the washing machine of the present embodiment, the pump 34 is provided in the water passage 19 separately from the centrifugal separation unit 20, and the control unit 21 controls the circulation of the washing water by the pump 34.

According to this configuration, the washing water can be circulated so as to pass through the centrifugal separation unit 20, and the water level of the washing water in the washing tub including the outer tub 1 and the rotary tub 4 can be optimized.

In the first and second embodiments, a drum-type washing machine is described as an example of a washing machine, but the present invention is not limited to this. In short, any washing machine may be used as long as it washes laundry with washing water. That is, the present invention can be applied to any washing machine having any structure, such as a structure for performing beat washing like a drum-type washing machine, a structure for performing agitation washing like a vertical-type washing machine, or a structure for performing press washing or shower washing in a housing case.

The washing machine in the first publication includes: a washing tank for storing the object to be washed and washing water; a water path for circulating the washing water in the washing tank; a centrifugal separation part which is arranged on the water path and is used for separating foreign matters contained in the washing water flowing in the water path; a pump section for circulating wash water between the wash tank and the centrifugal separation section through a water path; and a control part for controlling the washing operation. The centrifugal separation part comprises: a housing connected in communication with the water path; a rotary cylinder rotatably provided in the housing; and a rotary drum motor for rotating the rotary drum, wherein the control part controls the rotary drum motor to change the rotation speed of the rotary drum in a mode that the speed difference between the rotation speed of the rotary drum and the speed of the swirling flow of the washing water in the rotary drum is below a specified value.

According to this configuration, the rotational speed of the spin basket can be changed slowly, and the speed difference between the rotational speed of the spin basket and the speed of the swirling flow of the washing water in the spin basket that changes with acceleration and deceleration of the spin basket can be reduced. Therefore, the foreign matter separated from the washing water when the rotation speed of the rotary drum changes can be prevented from dispersing into the washing water. That is, the state in which the foreign matter is held on the inner surface of the rotary cylinder is maintained. Therefore, the separated foreign matter can be prevented from adhering to the laundry again, and the cleaning effect can be improved. In addition, the circulation of the washing water can promote the washing water to be contained in the laundry, thereby further improving the washing effect.

In the second publication, particularly in the first publication, the predetermined value is set to a speed difference that can maintain a state in which the foreign matter separated by the centrifugal separation section is held on the inner surface of the rotary drum.

According to this configuration, the foreign matter can be maintained in the state of being held on the inner surface of the rotary drum when the rotation speed of the rotary drum changes. That is, the foreign matter separated from the washing water can be prevented from being dispersed in the washing water.

In the third disclosure, particularly in the first or second disclosure, an adjusting portion for controlling the flow of the washing water may be provided in the water path, and the control portion may control the circulation of the washing water by the adjusting portion.

According to this configuration, the water level of the water contained in the laundry in the washing tub and the water level of the washing water in the washing tub can be optimized.

In the fourth disclosure, particularly in any one of the first to third disclosures, the pump section may include a pump blade provided on an outflow side of a rotary drum through which the washing water passes, the pump blade being rotated integrally with the rotary drum, and the pump blade being rotated together with the rotary drum by a rotary drum motor to circulate the washing water between the centrifugal separation section and the washing tub through the water path.

According to this configuration, the washing water in the washing tank circulates through the centrifugal separation unit by the rotation of the rotary drum. The centrifugal separation part can be provided with a pump function for circulating the washing water with a simple structure.

In the fifth disclosure, particularly in the first or second disclosure, the pump section may be provided in the water path independently of the centrifugal separation section, and the control section may control the circulation of the washing water by the pump section.

According to this configuration, the washing water can be circulated so as to pass through the centrifugal separation unit, and the water level of the washing water in the washing tank can be optimized.

In the sixth disclosure, particularly in any one of the first to fifth disclosures, the controller may control the spin basket motor to rotate the spin basket at a rotation speed at which the foreign matter separated by the centrifugal separator can be held on the inner surface of the spin basket when the circulation of the washing water is stopped or when the amount of the circulating water is reduced.

According to this configuration, the state in which the foreign matter centrifugally separated from the washing water is held on the inner surface of the spin basket can be maintained when the circulation of the washing water is stopped or when the amount of circulating water is reduced.

In the seventh disclosure, particularly in any one of the first to sixth disclosures, the washing machine may further include a water amount detector for detecting a water level of the washing water in the washing tub, and the controller may stop or reduce the flow of the washing water in the water passage by the adjuster when the water amount detector detects that the washing water in the washing tub reaches the first water level during circulation of the washing water.

According to this configuration, the washing water in the washing tub can be maintained at a predetermined water level. Thus, air infiltration due to a drop in water level can be prevented. In addition, when the heater is provided at the bottom of the washing tank, overheating and the like caused by the heater being exposed from the water surface due to the drop of the water level can be prevented.

In the eighth disclosure, particularly in the seventh disclosure, the controller may start or increase the flow of the washing water in the water path by the adjuster when the water amount detector detects that the washing water in the washing tub has reached the second water level higher than the first water level when the adjuster stops or reduces the flow of the washing water in the water path.

According to this structure, the washing water in the washing tank can be maintained at a predetermined water level.

Industrial applicability

As described above, the washing machine according to the present disclosure can prevent foreign matter separated from washing water from dispersing into the washing water when the rotation speed of the rotary drum provided in the centrifugal separation unit changes. Therefore, the separated foreign matter can be prevented from being attached to the laundry again, and the washing effect can be improved, and thus the washing machine is useful as various washing machines.

Description of the reference numerals

1: an outer tub (washing tub); 4: a rotary tub (washing tub); 19. 19a, 19b: a water path; 20: a centrifugal separation section; 20a: a housing; 20b: a rotary drum; 20c: a rotary drum motor; 20d: an inner peripheral surface (inner surface); 20k is as follows: a pump blade (pump section); 21: a control unit; 23: a water amount detection unit; 32: an opening/closing valve (adjusting part); 33: an adjustment valve (adjustment unit); 34: a pump (pump section).

Claims

1. A washing machine is provided with:

a washing tank for accommodating the object to be washed and washing water;

a water path for circulating wash water within the wash tank;

a centrifugal separation part provided in the water path for separating foreign matters contained in the washing water flowing in the water path;

a pump section for circulating wash water between the wash tank and the centrifugal separation section through the water path; and

a control part for controlling the washing operation,

wherein the centrifugal separation part comprises: a housing connected in communication with the water path; a rotary cylinder rotatably provided in the housing; and a rotary drum motor that rotates the rotary drum,

the rotary tub has a washing water inlet and a washing water outlet,

the control unit controls the spin basket motor to change the rotation speed of the spin basket so that a speed difference between the rotation speed of the spin basket and a speed of the swirling flow of the washing water in the spin basket is equal to or less than a speed difference that can maintain a state in which the foreign matter separated by the centrifugal separation unit is held on the inner surface of the spin basket.

2. The washing machine according to claim 1, wherein,

an adjusting part for controlling the flow of the washing water is provided in the water path,

the control part controls the circulation of the washing water through the adjusting part.

3. The washing machine according to claim 1 or 2,

the pump section includes a pump blade provided on an outflow side of the rotary drum through which the washing water passes, the pump blade rotating integrally with the rotary drum,

the pump blade is rotated together with the spin basket by the spin basket motor to circulate the washing water between the washing tub and the centrifugal separation part through the water path.

4. The washing machine according to claim 1 or 2,

the pump section is provided in the water path independently of the centrifugal separation section,

the control part controls circulation of the washing water through the pump part.

5. The washing machine according to claim 1 or 2,

the control section controls the rotary drum motor,

when the circulation of the washing water is stopped or the amount of the circulating water is reduced, the spin basket motor is rotated at a rotation speed at which the foreign matter separated by the centrifugal separation unit can be held on the inner surface of the spin basket.

6. The washing machine according to claim 2, wherein,

and a water amount detecting part for detecting the water level of the washing water in the washing tank,

the control part stops or reduces the flow of the washing water in the water path through the adjusting part when the water quantity detecting part detects that the washing water in the washing tank becomes a first water level when the washing water circulates.

7. The washing machine according to claim 6, wherein,

the control part starts or increases the flow of the washing water in the water path through the adjustment part when the water amount detection part detects that the washing water in the washing tank becomes a second water level greater than the first water level when the flow of the washing water in the water path is stopped or reduced by the adjustment part.