KR102640363B1 - Method for controlling washing machine - Google Patents

Abstract

The method of controlling a washing machine of the present invention includes the step of rotating the drum in one direction so that laundry in a drum rotatably provided in a tub containing water does not fall on the inner peripheral surface of the drum, and rotating the drum in one direction. While performing, the rotational speed of the pump that supplies water discharged from the tub to at least one nozzle configured to spray water into the drum is increased.

Description

Control method for washing machine {METHOD FOR CONTROLLING WASHING MACHINE}

The present invention relates to a method of controlling a washing machine using a variable speed pump.

In general, a washing machine is a device that separates contaminants from clothes, bedding, etc. (hereinafter abbreviated as 'laundry') by using the chemical decomposition action of water and detergent and physical actions such as friction between water and laundry. It is a general term.

Such a washing machine includes a tub containing water, and a drum rotatably provided within the tub to accommodate laundry. Recent washing machines may be configured to circulate the water discharged from the tub using a circulation pump and spray the circulated water into the drum through a nozzle. However, in such a conventional washing machine, since the circulation pump rotates at a constant speed, the injection pressure of the nozzle is also constant.

Recently, new technologies have been developed to control the rotation of the drum in order to provide diversity to the flow of laundry loaded into the drum. However, when the water pressure sprayed through the nozzle is constant as in the prior art, there is a limitation in which significant performance improvement cannot be expected.

In particular, when water is sprayed through a nozzle while performing a filtration motion in which the drum is driven to rotate integrally with the drum while the laundry is stuck to the inner peripheral surface of the drum, a conventional circulation pump operating at a constant speed cannot be used. There was a problem in that it was not possible to effectively wet both the laundry attached to the front end of the drum and the laundry attached to the rear part (i.e., deep within the drum). For example, if the rotational speed (or discharge water pressure) of the circulation pump is configured such that the water sprayed through the circulation nozzle reaches deep into the drum, the water sprayed from the nozzle will be applied to the laundry attached to the front end of the drum. Conversely, if the rotational speed of the circulation pump is configured such that the water sprayed through the nozzle reaches the front end of the drum, there is a problem in which water cannot be applied to laundry located deep in the drum.

The problem that the present invention seeks to solve is, first, to provide a control method for a washing machine that improves washing performance by filtration motion.

Second, it provides a control method for a washing machine in which both the laundry located at the front end of the drum and the laundry located at the rear end of the drum can be effectively wetted by water sprayed from a nozzle during filtration motion.

Third, considering the flow of laundry during filtration motion, a washing machine control method is provided that optimally controls the strength of the water flow sprayed through the nozzle so that the laundry can be well wetted.

The washing machine control method of the present invention includes the step of rotating the drum in one direction so that laundry in a drum rotatably provided in a tub containing water does not fall on the inner peripheral surface of the drum.

The washing machine includes at least one nozzle configured to spray water into the drum, and a pump that pumps water discharged from the tub to the at least one nozzle. The pump has a variable rotation speed.

While performing the step of rotating the drum in one direction, the rotational speed of the pump that supplies water discharged from the tub to at least one nozzle configured to spray water into the drum is increased.

The washing machine control method of the present invention has the effect of evenly wetting the laundry in the drum by increasing the rotational speed of the pump during filtration motion. That is, in the case where a large amount of foam is injected, the water pressure of the water stream sprayed from the nozzle is increased in response to the process of expanding the empty space in the drum in the depth direction of the drum, so that the sprayed water stream flows further into the drum through the empty space. It reaches deep into the drum and can effectively wet laundry located deep within the drum.

In addition, the washing machine control method of the present invention varies the rotational speed of the pump, so that during the filtration motion, both the laundry located at the front end of the drum and the laundry located at the rear end can be effectively wetted by water sprayed from the nozzle. It works.

1 is a perspective view showing a washing machine according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view of the washing machine shown in FIG. 1.
Figure 3 is a block diagram showing the control relationship between main parts of a washing machine according to an embodiment of the present invention.
Figure 4 schematically shows the main components of a washing machine according to an embodiment of the present invention.
Figure 5 is a diagram showing drum driving motions that can be implemented by a washing machine according to an embodiment of the present invention.
Figure 6 is a graph comparing the cleaning power and vibration level of drum driving motions.
Figure 7 is a graph showing the pump rotation speed range according to drum driving motions.
Figure 8 shows the change in rotation speed of the drum (a) and the change in rotation speed of the pump (b) according to an embodiment of the present invention.
Figure 9 shows the change in rotation speed of the drum (a) and the change in rotation speed of the pump (b) according to another embodiment of the present invention.
Figure 10 shows the arrangement of laundry in a drum while a filtration motion is being performed. (a) shows a case where a small amount of laundry is placed in the drum, and (b) shows a case where a large amount of laundry is placed into the drum.
Figure 11 shows the entire washing sequence applied to the washing machine of the present invention.
Figure 12 shows the moisture content according to the position of the cloth in the drum when the rotation speed of the pump is fixed at 3600 rpm while the filtration motion is performed and when the rotation speed of the pump is increased from 0 to 4600 rpm. will be.

The advantages and features of the present invention and methods for achieving them will become clear by referring to the embodiments described in detail below along with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. The present embodiments are merely provided to ensure that the disclosure of the present invention is complete and to be understood by those skilled in the art. It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

1 is a perspective view showing a washing machine according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the washing machine shown in FIG. 1. Figure 3 is a block diagram showing the control relationship between main parts of a washing machine according to an embodiment of the present invention. Figure 4 schematically shows the main components of a washing machine according to an embodiment of the present invention. Figure 5 is a diagram showing drum driving motions that can be implemented by a washing machine according to an embodiment of the present invention. Figure 6 is a graph comparing the cleaning power and vibration level of drum driving motions. Figure 7 is a graph showing the pump rotation speed range according to drum driving motions. Figure 8 shows the change in rotation speed of the drum (a) and the change in rotation speed of the pump (b) according to an embodiment of the present invention. Figure 9 shows the change in rotation speed of the drum (a) and the change in rotation speed of the pump (b) according to another embodiment of the present invention. Figure 10 shows the arrangement of laundry in a drum while a filtration motion is being performed. (a) shows a case where a small amount of laundry is placed in the drum, and (b) shows a case where a large amount of laundry is placed into the drum. Figure 11 shows the entire washing sequence applied to the washing machine of the present invention. Figure 12 shows the moisture content according to the position of the cloth in the drum when the rotation speed of the pump is fixed at 3600 rpm while the filtration motion is performed and when the rotation speed of the pump is increased from 0 to 4600 rpm. will be. Hereinafter, a washing machine control method according to embodiments of the present invention will be described with reference to FIGS. 1 to 12.

Referring to Figures 1 to 4, the casing 10 forms the exterior of the washing machine, and an inlet 12h through which laundry is put is formed on the front. The casing 10 may include a cabinet 11 with an open front, a left side, a right side, and a rear, and a front panel 12 coupled to the open front of the cabinet 11 and having an inlet 12h. You can. The bottom and top surfaces of the cabinet 11 are open, and a horizontal base (not shown) supporting the washing machine can be coupled to the bottom surface. In addition, the casing 10 includes a top plate 13 that covers the open upper surface of the cabinet 11, and a control panel 14 that is disposed on the upper side of the front panel 12 and forms a part of the front of the casing 10. ) may further be included.

The door 20 that opens and closes the inlet 12h may be rotatably coupled to the casing 10. The door 20 is open at approximately the center and may include a door frame 21 rotatably coupled to the front panel 12, and a window 22 installed at the open center of the door frame 21. .

A tub 31 containing water may be disposed within the casing 10. The tub 31 has an inlet formed on the front so that laundry can be put in, and the inlet is connected to the inlet formed in the casing 10 by a gasket 60.

The gasket 60 is used to prevent water contained in the tub 31 from leaking. The front end is coupled to the front (or front panel 12) of the casing 10, the rear end is coupled to the entrance of the tub 31, and the space between the front and rear ends extends in a tubular shape. The gasket 60 may be made of a flexible or elastic material. The gasket 60 may be made of natural rubber or synthetic resin.

The gasket 60 is connected to the tub from the casing coupling portion 61 coupled around the inlet of the casing 10, the tub coupling portion 62 coupled around the inlet of the tub 31, and the casing coupling portion 61. It may include an extension part 63 extending to the part 62.

A flat portion 64 is formed in the extension portion 63 that extends evenly from the casing coupling portion 61 toward the tub coupling portion 62, and is formed between the flat portion 64 and the tub coupling portion 62. A folded portion 65 may be formed.

The folding portion 65 is folded or unfolded when the tub 31 moves in an eccentric direction. The folded portion 65 may be formed over the entire circumference of the gasket 60.

The nozzles 83a and 83b may be installed on the flat portion 64. Depending on the embodiment, the nozzles 83a and 83b may be formed integrally with the flat portion 64, but this is not limited to this. A nozzle fastener (not shown) is formed on the flat portion 64, and the gasket 60 ) and the nozzle inlet pipe (not shown, a pipe through which water pumped by a pump flows) formed as a separate part may be inserted/fixed into the nozzle fastener. In either case, preferably, the outlet of the nozzle that sprays water toward the drum 40 is located on the inside surrounded by the gasket 60, and the circulating water guide pipe 18 is located on the outside of the gasket 60. It is connected to the inlet pipe.

The front panel 12 has the periphery of the inlet rolled outward, and the casing coupling portion 61 is fitted into the concave portion formed by the outer peripheral surface of the rolled portion. An annular groove in which a wire is wound is formed in the casing coupling portion 61, and after the wire is wound along the groove, both ends of the wire are bound, so that the casing coupling portion 61 is formed so that the front panel 12 is formed around the inlet. It is firmly fixed on.

A drum 40 containing laundry is rotatably provided within the tub 31. A plurality of through holes 47 communicating with the tub 31 may be formed in the drum 40 . Additionally, a lifter 45 may be provided on the inner peripheral surface of the drum 40 to lift the laundry when the drum 40 rotates.

The drum 40 accommodates laundry, is arranged so that the inlet through which the laundry is loaded is located at the front, and rotates about a substantially horizontal rotation center line C. However, “horizontal” here is not a term used in a mathematically strict sense. That is, as in the embodiment, when the rotation center line C is inclined at a predetermined angle (for example, 5 degrees or less) with respect to the horizontal, it is also close to the horizontal, so it can be said to be approximately horizontal.

The tub 31 may be supported by a damper 16 installed at the bottom of the casing 10. Vibration of the tub 31 caused when the drum 40 rotates is attenuated by the damper 16.

A water supply hose (not shown) that guides water supplied from an external water source such as a faucet to the tub 31 and a water supply valve (not shown) that controls the water supply hose may be provided.

A drain for discharging water is formed in the tub 31, and a drain bellows 17 may be connected to the drain. A pump 36 may be provided to pump the water discharged into the drainage bellows 17.

The pump 36 can selectively perform the function of pumping water discharged through the drain bellows 17 to the drain pipe 19 and the function of pumping water to the circulating water guide pipe 18, which will be described later.

The pump 36 may include an impeller (not shown) for pumping water, a pump housing (not shown) in which the impeller is accommodated, and a pump motor 92 that rotates the impeller. The pump housing includes an inflow port (not shown) through which water flows in through the drainage bellows 17, a drainage discharge port (not shown) through which water pumped by the impeller is discharged to the drain pipe 18, and the water discharged by the impeller. A circulating water discharge port (not shown) may be formed to discharge the pressured water to the circulating water guide pipe 18.

The pump motor 92 may be capable of forward/reverse rotation. Depending on the direction in which the impeller rotates, water may be discharged through a drainage discharge port or a circulating water discharge port. This configuration can be implemented by appropriately designing the structure of the pump housing, and since this technology is already known in Korean Patent Publication No. 10-2013-0109354, etc., detailed description will be omitted.

The inlet of the circulating water guide pipe 18 is connected to the circulating water discharge port, and the outlet is connected to nozzles 83a and 83b, which will be described later. However, it is not limited to this, and a circulation pump that pumps the water discharged from the tub 31 to the circulating water guide pipe 18 and a drainage pump that pumps the water discharged from the tub 31 to the drain pipe 19 are separate. It can be provided. Under the control of a control unit (not shown), the circulation pump may be operated (eg, during washing) or the drain pump may be operated (eg, during draining) according to a preset algorithm. Hereinafter, the pump 36 is exemplified as a circulation pump for both drainage and drainage.

Meanwhile, the pump motor 92 is a variable speed motor whose rotation speed is controlled. Depending on the embodiment, when a circulation pump is provided separately from the drainage pump, the pump motor constituting the circulation pump may be a variable speed motor. The pump motor 92 is preferably a BLCD motor (Brushless Direct Current Motor), but is not necessarily limited to this. A driver for controlling the speed of the pump motor 92 may be further provided, and the driver may be an inverter driver. The inverter driver converts AC power to DC power and inputs it to the motor at the target frequency.

A control unit 91 that controls the pump motor may be further provided. The control unit 91 may be configured to include a proportional-integral controller (PI controller), a proportional-integral-derivative controller (PID controller), etc. The controller receives the output value (for example, output current) of the pump motor 92 as input, and based on this, the rotation speed (or number of rotations) of the pump motor 92 is set to a preset target rotation speed (or target rotation speed). The output value of the driver can be controlled to follow the number of revolutions.

Meanwhile, the control unit 91 can control not only the pump motor 92 but also the overall operation of the washing machine, and the control of each part mentioned below is understood to be controlled by the control unit 91, even if not specifically mentioned. Let's do it.

At least one nozzle (83a, 83b) may be provided for spraying the circulating water pumped by the pump 36 into the drum 40. In the embodiment, the nozzles 83a and 83b provided on both the left and right sides of the gasket 60 are configured to spray water upward from below the center of the drum 40, but it is not necessarily limited to this. That is, the number and location of the nozzles can be modified in various ways, but in any case, the washing machine according to an embodiment of the present invention sprays water deeper into the drum 40 as the supplied water pressure increases. It is preferable to include one or more nozzles, and further, the nozzles are preferably configured to spray water more upward as the supplied water pressure increases.

Alternatively, a plurality of nozzles are configured, and at least one of these nozzles is configured to spray water deeper into the drum 40 as the supplied water pressure increases, and the other at least one nozzle is configured to spray water deeper as the supplied water pressure increases. It may be configured to spray water upward.

The outlet of each nozzle (83a, 83b) may open upward toward the inside of the drum (40). Therefore, when water is supplied above a certain water pressure, spraying through each nozzle (83a, 83b) is done in an upward slanting direction toward the inside of the drum (40), and the sprayed water reaches deep into the drum (40). This can be achieved.

On the other hand, when the water pressure of the water supplied to the nozzles (83a, 83b) is not sufficient, the water sprayed through the outlets of the nozzles (83a, 83b) does not sufficiently proceed upward and is easily lowered by gravity, so the drum (40) ) It does not reach deep into the medial area.

In Figure 4, the spray form when water is supplied by the pump 36 with sufficient water pressure is indicated as "a", and when the water pressure is lower than that, it is indicated as "b". That is, as the rotational speed of the pump 36 varies, the form of the water flow sprayed through the nozzles 83a and 83b may vary between a and b.

Figure 5 is a diagram showing drum driving motions that can be implemented by a washing machine according to an embodiment of the present invention. Below, with reference to FIG. 5, drum driving motions will be described in detail.

The drum driving motion refers to a combination of the rotation direction and rotation speed of the drum 40. Due to the drum driving motion, the falling direction or point of falling of the laundry located inside the drum 40 changes, and as a result, the drum 40 ) The flow of laundry inside changes. The drum driving motion is implemented by controlling the driving motor 93 by the control unit 91.

When the drum 40 rotates, the laundry is lifted by the lifter 45 provided on the inner peripheral surface of the drum 40, so the impact applied to the laundry can be varied by controlling the rotation speed and direction of the drum 40. do. In other words, it is possible to vary mechanical forces such as friction between laundry, friction between laundry and wash water, and impact of dropping laundry. In other words, the degree of tapping or rubbing of laundry can be varied for washing, and the degree of dispersion or turning of laundry can be varied.

Meanwhile, in order to implement these various drum driving motions, it is preferable that the drive motor 93 is a direct-coupled motor. That is, it is preferable that the stator of the motor is fixed to the rear of the tub 31, and the drive shaft 38, which rotates together with the rotor of the motor, directly drives the drum 40. This is because by controlling the rotation direction and torque of the motor, the drum driving motion can be immediately controlled by preventing temporal delay or backlash as much as possible.

On the other hand, in the form of transmitting the rotational force of the motor to the rotating shaft through a pulley, etc., a drum driving motion in which temporal delay or backlash is allowed, for example, tumbling driving or spin driving, is possible, but various other drum driving motions are possible. It is not suitable for implementing . Since the driving method of the driving motor 93 and the drum 40 is obvious to those skilled in the art, detailed description will be omitted.

Figure 5(a) is a diagram showing rolling motion. In the rolling motion, the drive motor 93 rotates the drum 40 in one direction (preferably, more than one rotation), but the laundry on the inner peripheral surface of the drum 40 rotates less than about 90 degrees in the rotation direction of the drum 40. It is a motion controlled to fall from the position toward the lowest point of the drum 40.

For example, when the drive motor 93 rotates the drum 40 at about 40 RPM, the laundry located at the lowest point of the drum 40 rises to a predetermined height along the rotation direction of the drum 40 and then falls into the drum 40. It flows toward the lowest point of the drum 40 as if rolling at a position less than about 90 degrees in the rotation direction from the lowest point. Visually, when the drum 40 rotates clockwise, laundry continues to roll in the three quadrants of the drum 40.

During the rolling motion, laundry is washed through friction with washing water, friction between laundry items, and friction with the inner peripheral surface of the drum 40. At this time, the laundry is sufficiently turned over, allowing the effect of gently rubbing and washing the laundry.

Here, the rotation speed (rpm) of the drum 40 is determined in relation to the radius of the drum 40. That is, as the rotation speed of the drum 40 increases, the centrifugal force acting on the laundry in the drum 40 also increases. Due to the size difference between the centrifugal force and gravity, the flow of laundry inside the drum 40 changes. Of course, the rotational force of the drum 40 and the frictional force between the drum 40 and the laundry must also be considered. In this way, considering various forces acting on laundry, the rotational speed of the drum 40 in rolling motion is determined in a range where the sum of centrifugal force and friction force is less than gravity (1G).

Figure 5(b) is a diagram showing tumbling motion. In the tumbling motion, the drive motor 93 rotates the drum 40 in one direction (preferably, more than one rotation), and the laundry on the inner peripheral surface of the drum 40 rotates about 90 to 110 degrees in the rotation direction of the drum 40. It is a controlled motion to drop from the position to the lowest point of the drum 40. The tumbling motion is a drum driving motion commonly used in washing and rinsing because mechanical force is generated simply by controlling the drum 40 to rotate in one direction at an appropriate rotation speed.

That is, the laundry put into the drum 40 is located at the lowest point of the drum 40 before the drive motor 93 is driven. When the drive motor 93 provides torque to the drum 40, the drum 40 rotates, and the laundry is moved by friction with the lifter 45 provided on the inner peripheral surface of the drum 40 or the inner peripheral surface of the drum 40. It rises from the lowest point in the drum 40 to a predetermined height. For example, when the drive motor 93 rotates the drum 40 at about 46 rpm, the laundry falls toward the lowest point of the drum 40 at a position of about 90 to 110 degrees in the rotation direction from the lowest point of the drum 40. do.

The rotation speed of the drum 40 in the tumbling motion can be set in a range in which centrifugal force is generated greater than in the rolling motion, but less than that of gravity.

Visually, the tumbling motion is that when the drum 40 rotates clockwise, the laundry rises from the lowest point of the drum 40 to a 90-degree position or the second quadrant, then separates to the inner circumferential surface of the drum 40 and reaches the lowest point of the drum 40. It takes the form of falling towards.

Therefore, during the tumbling motion, the laundry is washed by impact force caused by friction with the washing water and falling, and in particular, the laundry is washed by a greater mechanical force than in the case of the rolling motion. In particular, the tumbling motion has the effect of separating tangled laundry and dispersing the laundry.

Figure 5(c) is a diagram showing step motion. In the step motion, the drive motor 93 rotates the drum 40 in one direction (preferably less than 1 rotation), but the laundry on the inner peripheral surface of the drum 40 moves to the highest point of the drum 40 (drum 40). It is a motion controlled to fall toward the lowest point of the drum 40 at a position of approximately 180 degrees in the direction of rotation.

In other words, the step motion is the speed at which the laundry does not fall from the inner peripheral surface of the drum 40 due to centrifugal force (i.e., the speed at which the laundry rotates with the drum 40 while attached to the inner peripheral surface of the drum 40 due to centrifugal force). This is a motion that maximizes the impact force on the laundry by rotating the drum 40 and then suddenly braking the drum 40.

For example, when the drive motor 93 rotates the drum 40 at about 60 rpm or more, the laundry rotates (i.e., sticks to the inner peripheral surface of the drum 40) without falling due to centrifugal force. In this process, when the laundry is located near the highest point (180 degrees in the rotation direction) of the drum 40, torque in the opposite direction to the rotation direction of the drum 40 is applied to the drive motor ( 93) can be controlled to be applied.

After the laundry rises from the lowest point of the drum 40 along the direction of rotation of the drum, the drum 40 stops and falls from the highest point of the drum 40 to the lowest point. Therefore, the laundry falls to the maximum, and thus, it acts on the laundry. The impact force is also maximized. The mechanical force (eg, impact force) generated by this step motion is greater than the rolling motion or tumbling motion described above.

Visually, step motion means that when the drum 40 rotates clockwise, the laundry located at the lowest point of the drum 40 moves through the 3rd and 2nd quadrants to the highest point (180 degrees) of the drum 40 and then suddenly moves to the drum 40. (40) It separates from the inner peripheral surface and falls toward the lowest point of the drum (40). Therefore, the step motion provides mechanical power more effectively as the drop of laundry is the largest and the amount of laundry is small.

Meanwhile, as a control method of the drive motor 93 for braking the drum 40, reverse phase braking is preferable. Reverse phase braking is a method of braking by generating a rotational force in the opposite direction to the direction in which the drive motor 93 is rotating. The phase of the power supplied to the drive motor 93 can be reversed to induce rotational force in the opposite direction to the direction in which the drive motor 93 is rotating, and in this way, sudden braking is possible. Therefore, reverse phase braking is suitable for step motion.

After the drive motor 93 is braked, the drive motor 93 again applies torque to the drum 40 to raise the laundry at the lowest point of the drum 40 to the highest point. In other words, step motion is implemented by applying torque to rotate in the forward direction, then momentarily applying torque to rotate in the reverse direction to bring it to a sudden stop, and then applying torque to rotate in the forward direction again.

When the drum 40 rotates, the step motion washes the laundry by friction between the washing water flowing in through the hole 47 formed in the drum 40, and when the laundry is located at the highest point of the drum 40, it falls to avoid impact force. It can be said to be a washing motion.

Figure 5(d) is a diagram showing swing motion. The swing motion is a motion in which the driving motor 93 rotates the drum 40 in both directions, and is controlled so that the laundry falls at a position less than about 90 degrees in the rotation direction of the drum 40.

For example, when the drive motor 93 rotates the drum 40 counterclockwise at about 40 rpm, the laundry located at the lowest point of the drum 40 rises counterclockwise to a predetermined height. At this time, the drive motor 93 stops the rotation of the drum 40 before the laundry reaches a position of about 90 degrees counterclockwise, and therefore, the laundry rotates in the drum 40 at a position less than about 90 degrees counterclockwise. moves toward the lowest point of

After the rotation of the drum 40 is stopped, the drive motor 93 rotates the drum 40 clockwise at about 40 RPM so that the laundry moves in the rotation direction of the drum 40 (i.e. clockwise). So that it rises to a certain height. And, before the laundry reaches a position of about 90 degrees clockwise, the drive motor 93 is controlled so that the rotation of the drum 40 is stopped, so that the laundry moves to the drum 40 at a position of less than about 90 degrees clockwise. moves toward the lowest point of

In other words, the swing motion is a motion in which the forward rotation/stop of the drum 40 and the reverse rotation/stop are repeated. Visually, the laundry located at the lowest point of the drum 40 passes through the third quadrant of the drum 40, making it 2 It can be said to be a form of repeating the process of rising to the fourth quadrant, falling gently, passing through the fourth quadrant of the drum 40 again, rising to the first quadrant, and then falling gently. That is, visually, the swing motion is a form in which laundry flows in the shape of an eight lying on its side across the third and fourth quadrants of the drum 40.

At this time, power generation braking is suitable for braking the drive motor 93. Dynamic braking minimizes the load occurring on the drive motor 93, minimizes mechanical wear of the drive motor 93, and at the same time controls the impact applied to the laundry.

Dynamic braking is a braking method that uses the fact that the drive motor 93 functions as a generator due to rotational inertia when the current applied to the drive motor 93 is turned off. When the current applied to the drive motor 93 is turned off, the direction of the current flowing in the coil of the drive motor 93 is opposite to the direction of the current before turning off the power, so a force ( Fleming's right-hand rule) acts to brake the drive motor 93. Unlike reverse-phase braking, dynamic braking does not suddenly brake the drive motor 93 and allows the rotation direction of the drum 40 to change smoothly.

Figure 5(e) is a diagram showing scrub motion. The scrub motion is a motion in which the drive motor 93 alternately rotates the drum 40 in both directions and is controlled so that the laundry falls at a position of about 90 degrees or more in the rotation direction of the drum 40.

For example, when the drive motor 93 rotates the drum 40 in the forward direction at about 60 rpm or more, the laundry located at the lowest point of the drum 40 rises to a certain height in the forward direction. At this time, the drive motor 93 provides reverse torque to the drum 40 after the laundry passes a position of about 90 degrees in the forward direction to temporarily stop the rotation of the drum 40. Then, the laundry on the inner peripheral surface of the drum 40 falls rapidly.

Afterwards, the drive motor 93 rotates the drum 40 in the reverse direction at about 60 rpm or more to raise the fallen laundry again in the reverse direction to a predetermined height of 90 degrees or more. When the laundry passes the 90 degree position in the reverse direction, the drive motor 93 provides reverse torque to the drum 40 again to temporarily stop the rotation of the drum 40. At this time, the laundry on the inner peripheral surface of the drum 40 falls toward the lowest point of the drum 40 at a position of 90 degrees or more in the reverse direction.

Scrub motion washes laundry by causing the laundry to fall rapidly from a predetermined height. At this time, it is preferable that the drive motor 93 is subjected to reverse phase braking to brake the drum 40.

Since the rotation direction of the drum 40 is rapidly changed, the laundry does not significantly deviate from the inner peripheral surface of the drum 40, making it possible to obtain a very powerful scrubbing effect.

Scrub motion is a form in which laundry moves in the forward direction through the 3rd quadrant to the 2nd quadrant, falls rapidly, then moves in the reverse direction through the 4th quadrant to part of the 1st quadrant and then repeats the fall. Therefore, visually, it can be said that the laundry repeatedly rises and then falls along the inner peripheral surface of the drum 40.

Figure 5(f) is a diagram showing filtration motion. In the filtration motion, the drive motor 93 rotates the drum 40 so that the laundry does not fall off the inner peripheral surface of the drum 40 due to centrifugal force, and in this process, the laundry water flows into the drum 40 through the nozzles 83a and 83b. It is a spraying motion.

After the laundry is spread out, the washing water is sprayed into the inside of the drum 40 while rotating in close contact with the inner peripheral surface of the drum 40. Therefore, the sprayed washing water penetrates the laundry by centrifugal force and then passes through the through hole 47 of the drum 40. ) and exits through the tub (31).

The filtration motion expands the surface area of the laundry, and because the wash water penetrates the laundry, the laundry is evenly wetted.

Figure 5(g) is a diagram showing a squeeze motion. In the squeeze motion, the drive motor 93 rotates the drum 40 so that the laundry does not fall off the inner peripheral surface of the drum 40 due to centrifugal force, and then lowers the rotation speed of the drum 40 to remove the laundry from the inner peripheral surface of the drum 40. This is a motion in which the separation operation is repeated and the washing water is sprayed into the drum 40 through the nozzles 83a and 83b while the drum 40 is rotating.

The filtration motion continues to rotate at a speed that prevents the laundry from falling off the inner circumferential surface of the drum 40, but the squeeze motion changes the rotational speed of the drum 40 to repeatedly attach and separate the laundry from the inner circumferential surface of the drum 40. There is a difference in

Figure 6 is a graph comparing the cleaning power and vibration level of drum driving motions. In Figure 6, the horizontal axis represents cleaning power, and the farther left it goes, the easier it is to separate the dirt contained in the laundry. The vertical axis represents the vibration or noise level. As you move toward the top, the vibration level increases, but the washing time for the same laundry decreases.

Step motion and scrub motion have excellent cleaning power and are suitable for washing when laundry is heavily contaminated and for shortening washing time. Additionally, step motion and scrub motion are motions with high levels of vibration and noise. Therefore, this is an undesirable motion when the laundry is sensitive or in a laundry course that needs to minimize noise and vibration.

Rolling motion is a motion characterized by excellent cleaning power, low vibration level, minimal damage to laundry, and low motor load. Therefore, it can be applied to all washing courses, but it is especially suitable for dissolving detergent and wetting laundry at the beginning of washing. However, the rolling motion has a disadvantage that the vibration level is lower, but the washing time takes longer when washing to the same level compared to the tumbling motion.

The tumbling motion has lower cleaning power than the scrub motion, but the vibration level is intermediate between the scrub motion and rolling motion. The tumbling motion can be applied to all washing cycles, but is especially useful for the hair dispersion step.

The squeeze motion has a similar jaw thrust force to the tumbling motion, and the vibration level is higher than that of the tumbling motion. The squeeze motion is useful in the rinsing step because the washing water passes through the laundry and is discharged to the outside of the drum 40 in the process of repeating the adhesion and separation of the laundry to the inner peripheral surface of the drum 40.

Filtration motion is a motion in which the cleaning power is lower than that of the squeeze motion and the level of noise is similar to the rolling motion. The filtration motion is a useful motion when wetting the laundry or adding detergent water to the laundry at the beginning of washing because the washing water passes through the laundry and is discharged into the tub 31 while the laundry is in close contact with the inner peripheral surface of the drum 40.

Swing motion is the motion with the lowest vibration level and cleaning power. Therefore, the swing motion is a useful motion for low-noise or low-vibration laundry courses, and is a motion suitable for washing sensitive clothes (gentle care).

Referring to FIG. 7, while a scrub motion or a step motion is being performed, the rotational speed of the pump 36 (or the rotational speed of the pump motor 93) may vary between the rotational speed Pr1 and the rotational speed Pr5. That is, while the scrub motion or step motion is being performed, in the section where the laundry located at the lowest point of the drum 40 is raised, the rotational speed of the pump 36 is gradually increased, and the water sprayed through the nozzles 83a and 83b is also gradually increased. When the laundry located at the lowest point of the drum 40 rises to the maximum and the drum 40 is braked, the rotational speed of the pump 36 begins to decrease. The rotational speed of the pump 36 can be controlled by the control unit 91. Hereinafter, unless otherwise stated, it will be understood that the operations of the pump motor 92 and the drive motor 93 are controlled by the control unit 91.

Pr1 can be set within a range that allows injection to occur at least through the nozzles 83a and 83b. That is, even if the rotational speed of the pump 36 changes while the scrub motion or step motion is being performed, injection through the nozzles 83a and 83b is continuously performed. In the embodiment, Pr1 is approximately 1700 rpm, but is not necessarily limited thereto.

Pr5 is preferably set in a range where the water flow sprayed from the nozzles 83a and 83b can reach the highest point of the drum 40, but depending on the capacity of the pump 36, it may not reach this level.

While the tumbling motion is being performed, the rotation speed of the pump 36 can be determined approximately based on the rotation speed Pr3. In an embodiment, Pr3 is 3500 rpm, but is not necessarily limited thereto. While the tumbling motion is being performed, the control unit 91 can control the rotational speed of the pump 36 to remain constant.

While the rolling motion is being performed, the rotational speed of the pump 36 is set in a band lower than the rotational speed of the pump 36 in the tumbling motion, and can be determined based on the rotational speed Pr2. In an embodiment, Pr2 is 2800 rpm, but is not necessarily limited thereto. While the tumbling motion is being performed, the control unit 91 can control the rotational speed of the pump 36 to remain constant.

While the swing motion is being performed, the rotational speed of the pump 36 may vary approximately between Pr1 and Pr3. In the section where the laundry located at the lowest point of the drum 40 rises, the rotational speed of the pump 36 is gradually increased, so the water sprayed through the nozzles 83a and 83b gradually increases, and the laundry located at the lowest point of the drum 40 is raised. When it is raised to the maximum and the rotation direction of the drum 40 is reversed, the rotation speed of the pump 36 may also decrease.

While the filtration motion is being performed, the rotational speed of the pump 36 may vary approximately between Pr1 and Pr4. In the section where the drum 40 is accelerated, the pump 36 is also accelerated, and when the speed of the drum 40 is maximized, the pump 36 can also be rotated at the maximum rotation speed, and when the drum 40 is braked, the pump 36 is also accelerated. The rotational speed of the pump 36 can also be controlled to decrease. Pr4 may be lower than Pr5, and is 4600 rpm in the embodiment, but is not necessarily limited thereto.

Hereinafter, a washing machine control method according to an embodiment of the present invention will be described with reference to FIGS. 8 to 12.

A washing machine control method according to an embodiment of the present invention includes rotating the drum 40 in one direction so that the laundry in the drum 40 does not fall off the inner peripheral surface of the drum 40. This step corresponds to the filtration motion described above.

And, while the drum 40 is rotated in one direction (preferably more than one rotation) for the filtration motion as described above, the rotation speed of the pump 36 increases. In the process of carrying out the filtration motion, when the rotational speed of the drum 40 begins to increase, the centrifugal force acting on the laundry also increases, and the laundry located close to the inner surface of the drum 40 is sequentially moved to the drum 40. It is closely adhered or attached to the inner surface of the. That is, during the filtration motion, the rotational speed of the drum 40 begins to increase and reaches the preset rotational speed, but at the beginning, sufficient centrifugal force is not applied to the laundry located in the center of the drum 40, and thus the laundry. When the flow is generated and the rotational speed of the drum 40 increases sufficiently, the position of most of the laundry (preferably all laundry) in the drum 40 is fixed with respect to the drum 40.

In particular, when the amount of laundry put into the drum 40 is below a certain level, the laundry generally gathers at the entrance of the drum 40 during the filtration motion (see (a) of FIG. 10). In this case, it is better to control the rotational speed of the pump 36 low so that the circulating water sprayed from the nozzles 83a and 83b falls in front of the drum 40.

Conversely, when the amount of laundry loaded into the drum 40 is above a certain level, as the rotation speed of the drum 40 increases, the empty space surrounded by the laundry expands rearward from the entrance of the drum 40. , Ultimately, it takes the form shown in (b) of Figure 10. Controlling the rotational speed of the pump 36 to increase while the filtration motion is being performed is based on the mechanism of expansion of the empty space within the drum 40 as described above discovered during the filtration motion. . That is, in the process of expanding the empty space to the rear of the drum 40, the injection pressure of the nozzles 83a and 83b is also increased in conjunction, allowing the water flow to reach deep inside the drum 40. will be.

At this time, the rotational speed of the pump 36 may be configured to start increasing corresponding to the time point (t1) when the rotation of the drum 40 begins to accelerate. In other words, the acceleration of rotation of the drum 40 and the increase in rotation speed of the pump 36 are linked (or synchronized).

The graph indicated by a solid line in Figure 8(b) or Figure 9(b) shows the change in rotational speed of the pump 36 when the amount of laundry is above the standard value, and the graph indicated by a chain line shows the change in rotation speed of the pump 36 when the amount of laundry is above the reference value. In the case of less than 1, the change in rotational speed of the pump 36 is shown. As shown in these figures, the drum 40 may be braked when the rotational speed of the pump 36 reaches a preset maximum rotational speed (Pr(Fm), Pr(Fs)) (t=t2).

Meanwhile, as shown in FIG. 9, the rotational speed of the pump 36 increases to the preset injection rotational speed (Pr(md)) at the first acceleration slope (acceleration slope in the section from t1 to ts), The maximum rotation speed (Pr(Fm), Pr(Fs)) can be increased with a second acceleration slope (acceleration slope in the section from ts to t2) that is lower than the first acceleration slope.

The injection of water through the nozzles 83a and 83b is started at the latest when the rotational speed of the pump 36 reaches the injection rotational speed Pr(md). That is, at the latest when the rotational speed of the pump 36 reaches the injection rotational speed Pr(md), the water transferred through the circulating water guide pipe 18 must reach the nozzles 83a and 83b. In this respect, the first acceleration slope is preferably set to be larger than the second acceleration slope so that injection can be quickly performed through the nozzles 83a and 83b.

The washing machine control method according to embodiments of the present invention may further include detecting the amount of laundry (hereinafter referred to as “laundry amount”) in the drum 40. Various methods for obtaining weight are already known. For example, the control unit 91 accelerates the drum 40 with laundry (or laundry) loaded and determines the amount of laundry based on the time it takes for the rotational speed of the drum 40 to reach the preset rotational speed. You can. However, it is not limited to this, and the weight may be obtained using other known methods.

The spray rotation speed (Pr(md)) and the maximum rotation speed (Pr(Fm), Pr(Fs)) can be set according to the amount of laundry (i.e., laundry weight). As shown in FIG. 10, when the amount of laundry is relatively small (see (a) in FIG. 10), the laundry is concentrated at the inlet side of the drum 40, so the rotation speed of the pump 36 is adjusted to the amount of laundry. Even if the amount is changed in a relatively low area compared to the large amount (see (b) in FIG. 10), the laundry may be wet by the water flow sprayed from the nozzles 83a and 83b and falling.

Preferably, if the sensed amount of laundry is less than a preset reference value, the maximum rotation speed is set to the first rotation speed (Pr(Fs)), and if the sensed amount of laundry is more than the reference value, the maximum rotation speed is set to the first rotation speed. It may be set to a second rotation speed (Pr(Fm)) that is higher than the rotation speed.

Meanwhile, the spray rotation speed can also be set according to the amount of laundry. The spray rotation speed may be set higher when the amount of laundry is small compared to when the amount of laundry is large. That is, when the spray rotation speed is Pr(m) when the amount of laundry is large, it can be set to a value higher than Pr(m) when the amount of laundry is small.

For example, if the detected laundry amount is less than the reference value, the rotation speed of the pump 36 is quickly increased to 2400 rpm (injection rotation speed) to the first acceleration slope, and then the second acceleration slope (lower than the first acceleration slope) is increased. value) can be gently increased to 2800 rpm.

Meanwhile, if the detected amount of laundry is greater than the reference value, the rotation speed of the pump 36 is quickly increased to 2200 rpm (injection rotation speed) to the first acceleration slope, and thereafter, the second acceleration slope (a value lower than the first acceleration slope) is increased. It can be gently increased to 4600 rpm. Afterwards, the rotational speed of the pump 36 decreases, and the drum 40 is also braked and stopped.

As shown in FIG. 11, the washing machine may be configured to sequentially perform a water supply/wetting process, a dehydration process, a washing process, and a dehydration process. The water supply/wetting process is to wet the cloth by supplying water with detergent.

The washing cycle is a cycle that removes contamination from laundry by rotating the drum 40 according to a preset algorithm.

The dehydration process is a process that drains water and removes moisture from the cloth while rotating the drum 40 at high speed.

The rinsing process is an process that removes detergent from the cloth, water is supplied, and then the dehydration process can be performed again.

The step of controlling the pump 36 while performing the filtration motion described above is suitable for the water supply/wetting process among the above series of processes.

Meanwhile, Figure 12 shows the case where the rotation speed of the pump is fixed at 3600 rpm while the filtration motion is being performed (i.e., when using a conventional fixed rpm pump, indicated by a solid line) and the rotation speed of the speed variable pump 36. This shows the moisture content of the cloth located on the rear part 42 of the drum 40 when the speed is increased from 0 to 4600 rpm (in the case of one embodiment of the present invention, indicated by a dotted line). In the graph, the As shown in the drawing, it can be seen that in the case of the present invention, compared to the conventional case, the cloth located deep in the drum 40 is better wetted.

Claims (9)

A step of rotating the drum in one direction so that laundry in a drum rotatably provided in a tub containing water does not fall on the inner peripheral surface of the drum,
While performing the step of rotating the drum in one direction, increasing the rotational speed of a pump that supplies water discharged from the tub to at least one nozzle configured to spray water into the drum,
A method of controlling a washing machine further comprising: braking the drum when the rotational speed of the pump reaches a preset maximum rotational speed. According to claim 1,
The rotational speed of the pump is,
A control method for a washing machine that starts to rise in response to the point in time when the rotation of the drum begins to accelerate. delete According to claim 1,
The rotational speed of the pump is,
A method of controlling a washing machine in which the spray rotation speed increases to a preset speed with a first acceleration slope and then increases to the maximum rotation speed with a second acceleration slope lower than the first acceleration slope. According to claim 4,
A control method for a washing machine, wherein spraying of water through the at least one nozzle is started at the latest when the pump reaches the spraying rotation speed. According to claim 5,
Further comprising detecting the amount of laundry in the drum,
The maximum rotation speed is,
A washing machine control method set according to the detected amount of laundry. According to claim 6,
If the detected amount of laundry is less than a preset reference value, the maximum rotation speed is set to a first rotation speed,
If the detected amount of laundry is greater than the reference value, the maximum rotation speed is set to a second rotation speed higher than the first rotation speed. According to claim 7,
The injection rotation speed is,
A washing machine control method set according to the detected amount of laundry. According to claim 8,
The injection rotation speed is,
A control method for a washing machine where, when the detected amount of laundry is less than a preset standard value, the amount is set higher than when the detected amount of laundry is more than the reference value.

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