KR102521856B1 - Method and apparatus for washing machine - Google Patents

Abstract

The present invention includes a first washing tub accommodating laundry; a second washing tub disposed inside the first washing tub to rotate together with the first washing tub to accommodate laundry; a washing motor connected to the first washing tub to rotate the first and second washing tubs; and a control unit controlling a rotational speed of the washing motor, wherein the control unit accelerates the washing motor with at least a first acceleration until the washing motor reaches a predetermined target rotational speed, and then The present invention relates to a washing machine and a control method of the washing machine that prevent permanent deformation and noise of a second washing tub by accelerating with a large second acceleration.

Description

Washing machine and control method of washing machine {Method and apparatus for washing machine}

The present invention relates to a washing machine and a control method for the washing machine, and more particularly, to a control method for a washing machine having two washing tubs.

A washing machine is a device that removes contaminants from laundry (hereinafter referred to as “cloth”) through various actions such as washing, rinsing, and spin-drying using water and detergent.

Recently, a washing machine equipped with two washing tubs has been released. This washing machine is equipped with a large-capacity washing tub and a small-capacity washing tub that can be separated from each other, so that the washing tubs can be used simultaneously or a large-capacity washing tub or a small-capacity washing tub can be used alternatively according to the user's needs, so it is very economical. .

When two washing tubs are used at the same time, a small-capacity washing tub is coupled to a large-capacity washing tub, and a washing motor is connected to a large-capacity washing tub to rotate the two washing tubs to perform washing. In the section where the washing machine accelerates with a large acceleration for this purpose, the washing motor is overloaded, so power consumption increases and the temperature of the washing motor and the driver may rise excessively.

In addition, noise may be generated due to lifting of the small-capacity washing tub, and a torque greater than an allowable range may be applied to the coupled portion of the two washing tubs, resulting in permanent deformation.

An object to be solved by the present invention is, first, to provide a method for preventing lifting of a small-capacity washing tub in an acceleration section in which a high-speed rotation is required in a washing machine in which a second washing tub is installed in a first washing tub.

Second, it is to provide a method for preventing permanent deformation of the small-capacity washing tub by instantaneously transferring rotational force from a large-capacity washing tub to a small-capacity washing tub.

Third, it is to provide a method of reducing noise generation in an acceleration section.

Fourth, it is to provide a method of reducing power consumption in an acceleration section and reducing a temperature rise of a washing motor and a driver.

The tasks of the present invention are not limited to the tasks mentioned above, and other tasks not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a washing machine according to the present invention includes a first washing tub accommodating laundry; a second washing tub disposed inside the first washing tub to rotate together with the first washing tub to accommodate laundry; a washing motor connected to the first washing tub to rotate the first and second washing tubs; and a control unit controlling a rotational speed of the washing motor, wherein the control unit accelerates the washing motor with at least a first acceleration until the washing motor reaches a predetermined target rotational speed, and then Accelerate with a large second acceleration.

In order to achieve the above object, a control method of a washing machine according to the present invention includes (a) accelerating a washing motor connected to a first washing tub so that first and second washing tubs rotate; and (b) rotating the washing motor at a constant speed when the rotational speed of the washing motor reaches a predetermined target rotational speed. At least accelerating with a large second acceleration.

Before the step (a), water may be supplied to the second washing tub.

In the step (b), the washing motor accelerates with the first acceleration until the rotational speed of the washing motor reaches a predetermined intermediate rotational speed, and then the washing motor accelerates until the rotational speed reaches a predetermined target rotational speed. It can accelerate with the second acceleration.

The predetermined target rotation speed may be 100 rpm or more.

The predetermined intermediate rotational speed may be 80 rpm.

Details of other embodiments are included in the detailed description and drawings.

According to the washing machine and the washing machine control method of the present invention, one or more of the following effects are provided.

First, there is an advantage in preventing lifting of a small-capacity washing tub because the target rotational speed is reached by initially accelerating with a small acceleration in the acceleration section where high-speed rotation is required and then accelerating with a large acceleration.

Second, by reducing the torque required for the washing motor and the stress applied to the joint between the two washing tubs, there is an advantage in preventing permanent deformation of the small capacity washing tub.

Third, there is also an advantage in that noise is not generated by preventing lifting of a small-capacity washing tub.

Fourth, by accelerating with a small acceleration at the beginning of the acceleration section, the required power consumption is reduced and the temperature rise of the washing motor and driver is reduced.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a side cross-sectional view of a washing machine for implementing a control method for a washing machine according to a first embodiment of the present invention.
2 is a perspective view of the second washing tub shown in FIG. 1;
3 is an exploded perspective view of the second washing tub shown in FIG. 1;
4 is a perspective view illustrating the washing tub cover shown in FIG. 3;
5 is a perspective view illustrating a state in which a second washing tub is installed in a balancer.
Figure 6 is a plan view of the assembly shown in Figure 5;
FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. 6 .
8 is a cross-sectional view taken along line VIII-VIII of FIG. 7 .
9 is an example of an internal block diagram of the washing machine of FIG. 1 .
FIG. 10 is a diagram showing whether a second washing tub lifting phenomenon occurs according to a target rotational speed of a washing motor and the weight of fabrics accommodated in the second washing tub.
11 is a graph illustrating a comparison between a conventional basket motion (I) and a basket motion (II) according to the first embodiment of the present invention, in terms of a change in the rotational speed of the second washing tub.
12 is a flowchart illustrating a method for controlling a washing machine according to a first embodiment of the present invention.
13 is a graph showing changes in the rotational speed of the second washing tub in the basket motion according to the second embodiment of the present invention.
14 is a flowchart illustrating a control method of a washing machine according to a second embodiment of the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to completely inform the person who has the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Referring to FIGS. 1 to 9 , in the washing machine in which the control method according to the first embodiment of the present invention is implemented, the cabinet 2 forms the exterior and forms a space in which the water storage tank 4 is accommodated. The cabinet 2 is supported by a flat cabinet base 5, and includes a front, left side, right side and rear side, and the top side is open.

A top cover 3 may be coupled to the open upper surface of the cabinet 2 . An opening for putting in and taking out laundry (or “cloth”) may be formed in the top cover 3 . A door (not shown) for opening and closing the opening may be rotatably coupled to the top cover 3 .

The water tank 4 is for holding water and can be suspended in the cabinet 2 by the support rod 15. Support rods 15 may be provided at each of the four corners of the cabinet 2, one end of each support rod 15 is pivotally connected to the top cover 3, and the other end is a suspension that dampens vibration. It is connected to the water tank (4) by (27).

The water storage tank 4 has an open upper surface, and a water storage tank cover 14 may be provided on the open upper surface. The water reservoir cover 14 is formed in a ring shape with a substantially circular opening formed in the center thereof, and laundry is input through the opening.

In the storage tub 4, a first washing tub 6 that accommodates laundry and rotates around a vertical axis may be disposed. The vertical axis is substantially perpendicular to the ground. The vertical axis may be precisely aligned on a line perpendicular to the ground, but is not limited thereto, and may be tilted at a predetermined angle with respect to the vertical line. A plurality of through-holes 6h through which water passes are formed in the first washing tub 6, and water is exchanged between the first washing tub 6 and the water storage tank 4 through the through-holes 6h.

The first washing tub 6 may include a drum 6a having an open upper side and a through hole 6h formed therein, and a ring-shaped balancer 20 coupled to an upper portion of the drum 6a. The lower surface of the drum 6a may be connected to the rotation shaft of the drive unit 220 by the hub 7 .

A pulsator 9 may be rotatably provided at the inner lower portion of the first washing tub 6 . The pulsator 9 may include a plurality of radial wings protruding upward. When the pulsator 9 rotates, a water flow is formed by the blades.

The balancer 20 compensates for the eccentricity caused when the drum 6a rotates. The balancer 20 is coupled to the upper end of the drum 6a. 5 to 7, the balancer 20 may include a balancer body 21 forming ring-shaped cavities 20h1 and 20h2. A fluid (eg, salt water) or a plurality of weights (eg, metal spheres) may be inserted into the cavities 20h1 and 20h2. A plurality of the annular cavities 20h1 and 20h2 may be concentric but have different diameters.

If the drum 6a is tilted to one side during rotation, the eccentricity is corrected by moving fluids or weights in the opposite direction to the direction in which the drum 6a is tilted. Various forms of the ring-type balancer 20 applied to the washing machine are already known, and further description will be omitted.

The second washing tub 10 may be inserted into a space defined by the ring-shaped balancer 20 (or a substantially circular opening), and may be supported by the balancer 20 in an inserted state. The second washing tub 10 includes a container 30 containing laundry and a washing tub cover 60 covering the container 30 . The container 30 contains laundry and water, has an open upper surface, and the washing tub cover 60 covers at least a portion of the opened upper surface. The container 30 may be made of a transparent material so that the laundry accommodated inside can be seen from the outside.

A ring-shaped support portion 22 for supporting the container 30 may be formed on an inner diameter portion of the balancer body 21 (a portion forming an inner circle among two circles constituting the ring shape when viewed from above). In the support part 22, a plurality of engagement grooves 22c extending in the vertical direction are arranged along the circumferential direction. Each engagement groove 22c may have a spiral shape.

Threads 33 in the form of protrusions engaging with engagement grooves 22c formed in the support portion 22 may be formed on an outer surface of the container 30 . The thread 33 extends vertically in a form corresponding to the engagement groove 22c. That is, when the engagement groove 22c has a spiral shape, the thread 33 is also a protrusion extending in a spiral shape. Threads 33 are arranged in large numbers along the circumferential direction.

The threads 33 constitute a kind of helical gear and engage with the engagement grooves 22c formed in the support 22 of the balancer 20. Due to this structure, when the first washing tub 6 rotates, the second washing tub 10 can rotate integrally with the first washing tub 6 without spinning. In addition, since this type of coupling between the balancer 20 and the container 30 is also a kind of screw coupling, the coupling between the second washing tub 10 and the first washing tub 6 is firmly maintained. In particular, the second washing tub 10 can be fixed without descending due to the restraining force of the coupling between the thread 33 and the engagement groove 22c (for example, the frictional force acting between the surfaces engaged with each other).

The second washing tub 10 accommodates laundry and is detachably attached to the first washing tub 6 . That is, the second washing tub 10 is detachably coupled to the first washing tub 6 . When the first washing tub 6 is rotated in a state where the second washing tub 10 is installed, the second washing tub 10 is also rotated integrally with the first washing tub 6 .

The user can put the first laundry into the first washing tub 6 when the second washing tub 10 is not installed, or install the second washing tub 10 and put the second laundry into the second washing tub 10. there is.

A driving unit 220 providing power for rotating the first washing tub 6 and the pulsator 9 may be disposed in the cabinet 2 . The driving unit 220 is disposed below the water storage tank 4 and can be hung in the cabinet 2 while being coupled to the bottom of the water storage tank 4 . The driving unit 220 includes a washing motor 230 providing rotational force for driving at least one of the first washing tub 6 and the pulsator 9, a driver 240 controlling driving of the washing motor 230, A speed sensor 250 for sensing the rotational speed of the washing motor 230 may be included.

The rotating shaft of the driving unit 220 is always connected to the pulsator 9, and may be connected or disconnected from the first washing tub 6 according to a switching operation of the clutch 19. Therefore, when the driving unit 220 is operated in a state in which the rotating shaft of the driving unit 220 is connected to the first washing tub 6, the pulsator 9 and the first washing tub 6 are integrally rotated, and the rotating shaft When operating in a state in which the first washing tub 6 is disconnected (or separated), only the pulsator 9 rotates while the first washing tub 6 is stopped.

The driving unit 220 may include a washing motor 230 capable of speed control. The washing motor 230 may be a direct drive type inverter motor. The controller 210 may include a proportional-integral controller (PI controller), a proportional-integral-derivative controller (PID controller), and the like. The controller receives the output value (eg, output current) of the washing motor as an input, and based on this, the rotation speed (or rotation speed) of the washing motor follows a predetermined target rotation number (or target rotation speed). You can control it. The controller 210 may set a driving pattern of the washing motor 230, and the driver 240 may control driving of the motor 230 according to the driving pattern applied from the controller 210.

It should be understood that the control unit 210 may control not only the washing motor 230 but also the overall operation of the washing machine, and control of each component mentioned below is performed by the control of the control unit 210.

Meanwhile, the washing machine may include at least one water supply pipe 11 guiding water supplied from an external water source such as a tap. The at least one water supply pipe 11 may include a cold water pipe (not shown) receiving cold water from an external water source and a hot water pipe (not shown) receiving hot water.

A water supply valve 13 for controlling the water supply pipe 11 may be provided. When a plurality of water supply pipes 11 are provided, a plurality of water supply valves 13 are also provided, so that the water supply pipes 11 may be interrupted by the water supply valves 13, respectively. When at least one water supply valve 13 is opened under the control of the controller 210, water is supplied to the main dispenser 16 through the water supply pipe 11 corresponding to the opened water supply valve 13.

The main dispenser 16 supplies additives acting on the laundry to the drum 6a together with water supplied through the water supply pipe 11. Additives supplied by the main dispenser 16 include laundry detergent, fabric softener, bleach, and the like.

Meanwhile, the washing machine may further include a drain bellows 19a for discharging water from the water storage tank 4 and a drain valve 17 for controlling the drain bellows 19a. The drain bellows 19a may be connected to the pump 18. When the drain valve 17 is opened, water is supplied to the pump 18 through the drain bellows 19a. Water introduced into the pump 18 is discharged to the outside of the washing machine through the drain pipe 19b when the pump 18 is operated.

An inlet 60h is formed at the center of the washing tub cover 60 so that laundry can be put into the container 30 . The washing tub cover 60 includes a lower cover 40 and an upper cover 50 coupled to an upper side of the lower cover 40 .

The lower cover 40 may be coupled to an upper end of the container 30 . The lower cover 40 and the container 30 are each made of synthetic resin, and are coupled to each other preferably by welding, more preferably by thermal welding, but are not necessarily limited thereto.

The lower cover 40 has an inlet 452h through which the water flow that has risen in the container 30 flows when the first washing tub 6 rotates, and the water introduced through the inlet 452h is passed through the second washing tub 10. An outlet 431 for discharging to the outside is formed.

The upper cover 50 is coupled to the upper side of the lower cover 40 and defines a flow path from the inlet 452h to the outlet 431 between the lower cover 40 and the lower cover 40 . A check valve 91 opening and closing the inlet 452h may be provided on the flow path. The check valve 91 may be opened and closed by centrifugal force caused by rotation of the second washing tub 10 or by water pressure applied through the inlet 452h.

Between the lower cover 40 and the upper cover 50, a locking member 81 supported by a spring (not shown) may be provided. When the second washing tub 10 is rotated, the locking member 81 protrudes outward along the radial direction by centrifugal force and engages with the locking groove 22r formed in the balancer 20 . At this time, the spring is in a deformed state. When the second washing tub 10 is stopped, the locking member 81 escapes from the locking groove 22r and returns to its original position by the restoring force of the spring.

The upper cover 50 may be detachably coupled to the lower cover 40 . If necessary, the user may maintain or repair the check valve 91 after separating the upper cover 50 from the lower cover 40, and may clean the passage.

A first opening 40h is formed in the lower cover 40, and a second opening 50h communicating with the first opening 40h and constituting the inlet 60h is formed in the upper cover 50.

A water supply port 51h through which water discharged from the main dispenser 16 flows may be formed in the washing tub cover 60 . The washing tub cover 60 is provided with a sub dispenser 70 containing additives such as detergent, bleach or fabric softener, and the water supplied to the water inlet 51h passes through the sub dispenser 70 to the container with the additive ( 30) is supplied. The additive is preferably in liquid form so that it can be smoothly discharged through a siphon pipe 724 to be described later.

Water supply through the water inlet 51h may be performed a plurality of times. In this case, since the additives are all discharged through the siphon pipe 724 to be described later during the first water supply, water in which the additives are not dissolved (or , raw water) is watered.

On the other hand, when the second washing tub 10 is rotated at a sufficient speed, the water flow developed outward along the radial direction by the centrifugal force within the container 30 moves toward the inner surface of the container 30 (ie, the container body 31 ), and may be introduced into the washing tub cover 60 through an inlet 452h to be described later. A flow path guiding the water flow introduced through the inlet 452h is formed in the washing tub cover 60 .

The washing tub cover 60 may include a nozzle 62 that discharges the water flow guided along the passage to the outside of the washing tub cover 60 . The nozzle 62 may be inserted into and fixed to the outlet 431 formed in the lower cover 40 . The nozzle 62 may have a slit-shaped outlet extending long in the horizontal direction.

The outlet is open toward a lower side than the water tank cover 14 . The second washing tub 10 is rotated at high speed, so that the water discharged through the nozzle 62 may be guided along the lower surface of the water reservoir cover 14 .

As shown in FIG. 5, in a state where the second washing tub 10 is installed on the balancer 20, the nozzle 62 is positioned higher than the balancer 20 (that is, exposed to the upper side than the balancer 20 is), and therefore, the water injected through the nozzle 62 can reach the water tank 4 without interfering with the balancer 20.

Meanwhile, referring to FIG. 3 , a vane 35 extending long in the vertical direction may be provided on an inner surface of the container 30 . The vane 35 protrudes from the inner surface of the container 30 , is manufactured as a separate part from the container 30 , and may be installed in the container 30 . After the water flow generated by the rotation of the second washing tub 10 rises due to collision with the vane 35, it falls to the center of the container 30. A plurality of vanes 35 may be provided, and preferably, a plurality of vanes 35 are disposed symmetrically with respect to the center of rotation of the second washing tub 10 . In the embodiment, a pair of vanes 35 are provided, but the number of vanes 35 is not limited thereto.

The washing tub cover 60 may include a handle 61 formed around the inlet 60h. When looking down at the washing tub cover 60 from above, the inlet 60h is located on one side with respect to the handle 61, and the water supply inlet 51h is located on the other side. The handle 61 may be provided on both sides of the inlet 60h, respectively, and the water supply port 51h may also be provided on the other side of each handle 61, respectively.

The sub dispenser 70 may be provided on both sides of the washing tub cover 60, respectively. In this case, laundry detergent or bleach may be supplied through one of the pair of sub dispensers 70 and fabric softener may be supplied through the other.

The sub dispenser 70 may be provided on the lower cover 40 . The sub dispenser 70 may be disposed at a position corresponding to the pair of water supply inlets 51h. Hereinafter, the pair of sub-dispensers 70 are divided into a first sub-dispenser 70(1) and a second sub-dispenser 70(2).

Depending on the rotational position (or rotational angle) of the second washing tub 10, the water discharged from the main dispenser 16 is selectively directed to the first sub dispenser 70(1) or the second dispenser 70(2). can be watered with For example, by the controller 210, water is supplied to the first sub-dispenser 70(1) during the washing process and water is supplied to the second sub-dispenser 70(2) during the rinsing process. The rotational position (or rotational angle) of the second washing tub 10 may be controlled.

Each sub-dispenser 70 is accommodated in a drawer housing 71 and withdrawable in the drawer housing 71, and a drawer 72 with an open top surface and an open top surface of the drawer 72 A drawer cover 73 may be included. The drawer cover 73 may be detachably coupled to the drawer 72 . An opening 73h through which water discharged from the main dispenser 16 passes is formed in the drawer cover 73, and the water passing through the opening 73h is supplied into the drawer 72.

The upper cover 50 may include a flow guide 52 for guiding water introduced through the water supply port 51h to the sub dispenser 70 . The flow guide 52 forms an inclined surface to guide water downward, and the water guided along the inclined surface is guided to the opening 73h of the drawer cover 73.

The drawer 72 is a container with an open upper surface, and additives may be accommodated in the drawer 72 . The drawer 72 is coupled with the drawer housing 71 , and this coupling allows the drawer 72 to be inserted into or withdrawn from the drawer housing 71 .

The drawer 72 may be provided to be rotatable with respect to the drawer housing 71 . The connection link 721 (see FIG. 3 ) of the drawer 72 may be rotatably connected to the lower cover 40 . That is, the front end of the connection link 721 may be connected to the drawer 72 and the rear end may be rotationally coupled with the lower cover 40 .

An opening 715 through which the link 721 passes may be formed in the second side portion 714 of the drawer housing 71 .

However, it is not necessarily limited thereto, and according to embodiments, it is also possible to install the drawer housing 71 in a linearly slidable manner.

Referring to FIG. 7 , the drawer 72 may include a siphon tube 724 protruding upward from the bottom, and the drawer cover 73 is a siphon cap covering the siphon tube 724 ( 732) may be included.

An outlet of the siphon tube 724 is formed at the bottom of the drawer 72, and the siphon cap 732 forms a passage having an annular cross section between the outer circumferential surface of the siphon tube 724. Such a structure is suitable for supplying liquid additives.

When water is supplied to the sub-dispenser 70 and the water level in the drawer 72 gradually rises, the water rises along the passage having an annular cross section and passes through the inlet at the top of the siphon tube 724 ( 724), and then discharged into the container 30 through the outlet at the bottom of the siphon tube 724.

Meanwhile, in order for the laundry in the first washing tub 6 and the laundry in the second washing tub 10 to be washed simultaneously, water must be supplied to the first washing tub 6 while the second washing tub 10 is installed. Hereinafter, how water is supplied to the first washing tub 6 in a state where the second washing tub 10 is installed will be described.

Referring to FIG. 6, when viewed from above, the outer appearance of the second washing tub 10 is a first section S1 in contact with the support portion 22 of the balancer 20 and a second section S1 spaced apart from the support portion 22. A section (S2) may be included.

The first section S1 is located on a first axis (a line marked VII-VII) passing through the vertical axis O, and the second section S2 passes through the vertical axis O and is orthogonal to the first axis. It can be located on the axis (Y). The first section S1 may be formed on both sides to be symmetrical with respect to the second axis Y, and the second section S2 may be formed on both sides to be symmetrical with respect to the first axis.

When the second washing tub 10 is rotated and aligned to the first rotational position under the control of the drive unit 220 of the control unit 210, the water discharged from the main dispenser 16 flows through the second section S2 and the balancer Water can be supplied into the drum 6a of the first washing tub through the gap P1 or P2 formed between the inner circumferential surfaces of the 20. That is, the first rotation position is a position where the second washing tub 10 is aligned so that water discharged from the main dispenser 16 can pass through the gap P1 or P2.

In the embodiment, the second rotational position is a position where the first washing tub 6 is rotated 90 degrees from the first rotational position. However, when the position of the water inlet 51h is changed according to the embodiment, the angle between the second rotational position and the first rotational position may be changed. As described above, since the washing motor 230 is capable of speed control, the control unit 210 controls the rotation angle of the first washing tub 6 or the first washing tub 6 based on the speed of the washing motor 230. It is possible to control the rotational position of (6). Since the second washing tub 10 rotates integrally with the first washing tub 6, controlling the rotation angle or rotation position of the first washing tub 6 is equivalent to controlling the rotation angle or rotation position of the second washing tub 10. it is also

Meanwhile, the washing machine according to the present invention may be driven in a motion of alternately rotating the second washing tub 10 in forward and reverse directions for washing or rinsing fabrics accommodated in the second washing tub after supplying water to the second tub, , this method can be named as basket motion. That is, the control method of the washing machine according to the present invention can be applied to the basket motion, and the step of rotating in one direction of the basket motion can be described as the control method of the washing machine according to the present invention.

FIG. 10 is a diagram illustrating whether a lifting phenomenon of the second washing tub occurs according to a target rotational speed of a washing motor and the weight of fabric accommodated in the second washing tub in a basket motion. In the washing machine according to the present invention, when the target rotational speed of the basket motion is 80 rpm, lifting of the second washing tub does not occur. When the target rotation speed is 100 rpm, the lifting of the second washing tub does not occur when the amount of fabric accommodated in the second washing tub is 2 kg, but the lifting of the second washing tub occurs when no fabric is accommodated in the second washing tub. When the target rotational speed is 120 rpm, lifting of the washing tub occurs regardless of the amount of fabric accommodated in the second washing tub.

Accordingly, the washing machine control method according to the first embodiment of the present invention can be applied when the rotational speed of the washing motor is equal to or greater than a predetermined target rotational speed, a change in acceleration is required at a predetermined intermediate rotational speed, The target rotational speed of is 100 rpm or more. In addition, when the target rotational speed is 80 rpm, lifting of the second washing tub does not occur. In this case, a change in acceleration is unnecessary in the acceleration step. Therefore, the desired intermediate rotational speed is preferably 80 rpm.

11 is a graph illustrating a comparison between a conventional basket motion (I) and a basket motion (II) according to the present invention, in terms of rotational speed change of the second washing tub.

The washing machine and the washing machine control method according to the present invention include accelerating the washing motor 230 until it reaches a predetermined target rotation speed (T1, T2), and the rotation speed of the washing motor 230 reaching the predetermined target rotation speed. When it arrives, it includes a step (T3) of rotating at a constant speed, and the step of accelerating is a step of accelerating (T1) with a first acceleration (α1) and then accelerating (T2) with a second acceleration (α2) greater than the first acceleration (T2). ) at least.

Driving of the washing motor 230 is controlled by the driver 240 so that the speed of the washing motor 230 follows the target rotational speed applied from the controller 210 and accelerates. The controller 210 may set accelerations α1 and α2 in the step of accelerating the washing motor 230 as well as setting the target rotation speed. As shown in (II) of FIG. 11, the washing motor 230 is accelerated with the first acceleration α1 (T1), and then, at a certain point in time, with the second acceleration α2 greater than the first acceleration α1. It accelerates (T2). The washing motor 230 increases its acceleration at least once until reaching the target speed. For example, the first acceleration α1 may be 200 rpm/s, and the second acceleration α2 may be greater than 300 rpm/s. Hereinafter, a section accelerating at the first acceleration α1 is also referred to as a first acceleration section T1, and a section accelerating at the second acceleration α2 is also referred to as a second acceleration section T2.

A transition point from the first acceleration α1 to the second acceleration α2 may be determined based on the speed of the washing motor 230 . A speed at which the acceleration is changed (hereinafter, also referred to as “intermediate rotational speed”) may be set by the control unit 210, and the washing motor 230 is accelerated to the first acceleration α1 so that the speed sensor 250 When the rotational speed of the washing motor 230 sensed by ) reaches the intermediate rotational speed, the controller 210 controls the driver 240 to rotate the washing motor 230 at the second acceleration α2. can For example, the washing motor 230 may be accelerated with the first acceleration α1 until the rotational speed reaches 80 rpm, and then accelerated with the second acceleration until the rotational speed reaches the target rotational speed.

Alternatively, the transition time from the first acceleration α1 to the second acceleration α2 may be determined based on the driving time of the washing motor 230 . When the time during which the washing motor 230 is accelerated to the first acceleration α1 has elapsed, the controller 210 controls the driver 240 to accelerate the washing motor 230 to the second acceleration α2. can do. For example, after the first acceleration period T1 progresses for 0.4 seconds, the second acceleration period T2 may proceed until the rotational speed of the washing motor 230 reaches the target rotational speed.

After the controller 210 controls the washing motor 230 to accelerate at the second acceleration and reaches the target rotational speed, the controller 210 controls the washing motor 230 to rotate at a constant speed at the target rotational speed ( T3). After the washing motor 230 rotates at a constant speed for a predetermined number of times or for a predetermined time, the controller 210 brakes the washing motor 230 to control the first and second washing tubs 6 and 10 to stop.

After the second washing tub 10 is stopped, the control unit 210 controls the washing motor 230 to rotate in the opposite direction to that of the previous step, and details are the same as those described above and will therefore be omitted.

12 is a flowchart illustrating a control method of a washing machine according to a first embodiment of the present invention.

In the control method of the washing machine according to the first embodiment of the present invention, the washing motor 230 and the first and second washing tubs ( 6, 10) is accelerated until it reaches a predetermined target rotational speed.

First, the first and second washing tubs 6 and 10 are accelerated at a first acceleration (S110). The first and second washing tubs 6 and 10 are controlled by the driving unit 220 of the controller 210 until the rotation speed of the first and second washing tubs 6 and 10 reaches a predetermined intermediate rotation speed. It accelerates with 1 acceleration, and the rotational speed gradually increases.

When the rotation speed of the first and second washing tubs 6 and 10 reaches the predetermined intermediate rotation speed (S120), the first and second washing tubs 6 and 10 are accelerated at the second acceleration (S130). The speed detector 250 may detect a rotational position of a rotor (not shown) of the washing motor 230 and may detect a rotational speed of the washing motor 230 from the rotational position and time. When the rotational speed of the washing motor 230 detected by the speed sensor 250 reaches the intermediate rotational speed, the controller 210 controls the driver 240 to wash the washing motor 230 and the first and second rotational speeds. The washing tubs 6 and 10 rotate at the second acceleration.

The first and second washing tubs 6 and 10 are controlled by the driving unit 220 of the control unit 210 until the rotation speed of the first and second washing tubs 6 and 10 reaches a predetermined target rotation speed. It accelerates with 2 acceleration and the rotational speed gradually increases.

When the rotation speed of the first and second washing tubs 6 and 10 reaches the predetermined target rotation speed (S140), the first and second washing tubs 6 and 10 rotate at constant speed at the predetermined target rotation speed (S150). ). When the rotational speed of the washing motor 230 sensed by the speed sensor 250 reaches the target rotational speed, the controller 210 controls the driver 240 to wash the washing motor 230 and the first and second rotational speeds. The washing tubs 6 and 10 rotate at the target rotation speed.

After the first and second washing tubs 6 and 10 rotate at constant speed for a predetermined number of rotations or for a predetermined time, the control unit 210 brakes the washing motor 230 so that the first and second washing tubs 6 and 10 are Control to stop (S160).

13 is a graph showing changes in the rotational speed of the second washing tub in the basket motion according to the second embodiment of the present invention, and FIG. 14 is a flow chart showing a control method of the washing machine according to the second embodiment of the present invention. am.

In the control method of the washing machine according to the second embodiment of the present invention, the washing motor 230 and the first and second washing tubs ( 6, 10) is accelerated until it reaches a predetermined target rotational speed.

First, the first and second washing tubs 6 and 10 are continuously accelerated at an acceleration that gradually increases (S210). For example, if the rotational speed of the washing motor 230 is ω1, the acceleration (the tangential line in the graph) is a1, and the acceleration when ω2 is a2 (a2>a1), the acceleration in the section between ω1 and ω2 is continuously increased from a1 to a2.

When the rotation speed of the first and second washing tubs 6 and 10 reaches the predetermined target rotation speed (S220), the first and second washing tubs 6 and 10 rotate at constant speed at the predetermined target rotation speed (S230). After the first and second washing tubs 6 and 10 are rotated at constant speed for a predetermined constant speed rotation number or for a predetermined time, the controller 210 brakes the washing motor 230 so that the first and second washing tubs 6 and 10 ) is controlled to stop (S240).

In another embodiment of the present invention, there is a basket motion having a plurality of intermediate rotational speeds, for example, the rotational speeds of the first and second washing tubs are accelerated at the first acceleration until the rotational speeds of the first and second washing tubs reach the first intermediate rotational speed. After that, it can be accelerated with a second acceleration greater than the first acceleration until reaching the second intermediate rotational speed, and then accelerated with a third acceleration greater than the second acceleration until reaching the target rotational speed. Since this is an extension of the first embodiment, a detailed description thereof will be omitted.

The operation of the washing machine and the control method of the washing machine according to the present invention configured as described above will be described as follows.

Since the washing motor 230 is gently accelerated with the first acceleration α1 at the beginning of the basket motion, the peak of the current applied to the motor 230 compared to the prior art (indicated by (I) in FIG. 11) The value can be reduced, and the temperature rise of the driver 240 or the washing motor 230 is also reduced. In particular, at the beginning of the basket motion (T1), the engagement groove 22c of the balancer 20 of the first washing tub momentarily transmits rotational force to the thread 33 of the second washing tub 10, and the value of the target rotational speed And as the magnitude of the rotational acceleration is large and the weight of the fabric accommodated in the second washing tub 10 is light, lifting of the second washing tub 10 may occur, resulting in noise and permanent deformation of the second washing tub 10. there is a risk of Conversely, since the impact force applied to the fabric from the wash water supplied to the second washing tub 10 decreases as the magnitude of the acceleration α1 decreases, it becomes an obstacle to improving washing performance.

Therefore, in the present invention, the lifting of the second washing tub is prevented by gently accelerating the washing motor 230 (α1) at the beginning of the basket motion, and thereafter, by accelerating with a larger acceleration (α2), sufficient washing performance is obtained. There is an effect that can be secured.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and in the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Various modifications and implementations are possible by those skilled in the art, and these modifications should not be individually understood from the technical spirit or perspective of the present invention.

6: first washing tub 10: second washing tub
20: Balancer 22c: Matching groove
33: thread 210: control unit
220: driving unit 230: washing motor
240: driver 250: speed sensor

Claims (8)

A first washing tub including a drum accommodating laundry and a balancer having a ring shape opening upward and coupled to an upper portion of the drum;
a washing motor connected to the first washing tub to rotate the first washing tub;
a second washing tub including a container accommodating laundry and being inserted into the inner diameter of the balancer to rotate together with the first washing tub;
A control unit controlling a rotational speed of the washing motor;
The balancer includes a plurality of engagement grooves spirally extending in an up-and-down direction in the inner diameter part into which the first washing tub is inserted and arranged along a circumferential direction of the inner diameter part,
The second washing tub includes a plurality of threads protruding from the outer surface of the container, spirally extending in an up-and-down direction, engaged with the engagement groove, and arranged along a circumferential direction of the outer surface of the container;
The controller accelerates the washing motor with a first acceleration until the rotational speed of the washing motor reaches a predetermined intermediate rotational speed, and then accelerates the washing motor until the rotational speed of the washing motor reaches a predetermined target rotational speed. A washing machine accelerating the washing motor with a second acceleration greater than the first acceleration.
delete delete According to claim 1,
The controller rotates the washing motor at a constant speed when the rotational speed of the washing motor reaches the target rotational speed.
According to claim 1,
A water supply pipe connected to an external water source; and
Further comprising a water supply valve for regulating the water supply pipe
The control unit:
The washing machine supplies water to the second washing tub by controlling the water supply valve before accelerating the washing motor to the first acceleration.
delete According to claim 1,
The predetermined target rotation speed is 100 rpm or more.
According to claim 1 or 7,
The predetermined intermediate rotational speed is 80 rpm.

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