KR20200025558A - A washing machine and method of controlling the washing machine - Google Patents

Abstract

The present invention relates to a washing machine, which is formed such that a cylindrical drum formed by processing a metal board is rotated around a horizontal axis. The washing machine includes a plurality of protruding parts lengthily extended on an inner circumferential surface of the drum in a longitudinal direction and spaced apart along a circumferential direction. The height in which the protruding part protrudes toward the inside of the drum is 2.0 to 6.0 % of a diameter of the drum.

Description

Washing machine and washing machine control method {A WASHING MACHINE AND METHOD OF CONTROLLING THE WASHING MACHINE}

The present invention relates to a washing machine having a drum that rotates about a horizontal axis, and more particularly, to a washing machine having a height of a protrusion formed on an inner circumferential surface of the drum is less than 40 mm.

Washing machines configured to rotate the drum on which the laundry is introduced is rotated about a horizontal axis is widely known. For example, in the washing machine disclosed in Korean Patent Laid-Open Publication No. 10-2011-0022359, a lifter disposed on an inner circumferential surface of a drum pumps laundry upon rotation of the drum.

In the washing machine provided with the lifter in the drum, the laundry is lifted up to a certain height by the force applied by the lifter to the laundry, and the friction is induced between the lifter and the laundry. Therefore, it is possible to secure a certain level of washing power, which is less affected by the amount of water filled in the drum, the amount of laundry (package), and the rotational speed (RPM) of the drum, compared to a structure without a lifter. to be.

On the other hand, in the case of a drum without a lifter, the centrifugal force caused by the rotation of the drum becomes the power to lift the laundry. In this case, when the drum's rotational speed is equal to or greater than the wrapping speed, the centrifugal force applied to the laundry equals gravity. , The laundry is rotated to adhere to the inner peripheral surface of the drum. Although there is a variation depending on the diameter of the drum, the embedding speed is 90 to 110 rpm.

On the other hand, when the lifter is installed on the drum, since the lifter lifts up the laundry as well as the centrifugal force, the laundry may be rotated while the drum is stuck to the drum even when the drum's rotational speed is lower than 90 rpm. In the conventional washing machine, a lifter having a height of approximately 40 mm is applied. In this case, when the rotation speed of the drum reaches about 55 rpm, the laundry is rotated while being attached to the drum.

That is, such a conventional washing machine has to limit the rotational speed of the drum to about 55 rpm or less so that the laundry is lifted up by the lifter and falls. However, there are various factors that affect the washing force, as well as the drop of laundry by the lifter, friction between the drum and the laundry, the impact force of the lifter on the laundry, and the stretching of the laundry. In particular, since these factors are closely related to the rotational speed of the drum, there is a need to devise a method of rotating the drum at a higher speed than the conventional one while causing a drop of laundry.

The problem to be solved by the present invention is, first, to provide a washing machine to induce a drop of laundry by the rotation of the drum, the upper limit of the drum rotation speed that can induce the flow of the laundry compared to the prior art.

Secondly, a protrusion for pumping laundry is formed on the inner circumferential surface of the drum, and the height of the protrusion is properly designed so that the laundry can flow in the drum without sticking to the drum even if the rotation speed of the drum is 60 rpm or more. It is to provide a washing machine.

The present invention relates to a washing machine configured such that a cylindrical drum into which a cloth is inserted is rotated about a horizontal axis. A plurality of protrusions are provided on the inner circumferential surface of the drum. The protrusions extend in the front-rear direction on the inner circumferential surface, and a plurality of the protrusions are spaced apart along the circumferential direction of the drum.

The protrusion protrudes inwardly of the drum is 2.0 to 6.0% of the diameter of the drum. Alternatively, the protrusions protrude to the inside of the drum at a height of 10 to 30 mm.

On the inner circumferential surface of the drum, there is no protrusion structure higher than any one of the plurality of protrusions between a pair of adjacent protrusions arbitrarily selected among the plurality of protrusions.

The drum may further include a plurality of embossing protrusions formed on the inner circumferential surface lower than any of the plurality of protrusions. On the inner circumferential surface of the drum, there may be no protrusion structure other than at least one of the plurality of embossings between a pair of adjacent protrusions arbitrarily selected from among the plurality of protrusions. The height of the embossing may be 5 mm or less.

Between the adjacent pair of protrusions arbitrarily selected from among the plurality of protrusions, there is no protrusion structure on the inner circumferential surface of the drum, or at least one of the plurality of embossings is present.

The projecting portion has a first side portion that forms a positive first angle with the inner circumferential surface at a first point on the inner circumferential surface of the drum when viewed from the front, and the circumferential direction from the first point on the inner circumferential surface when viewed from the front. It may include a second side portion forming a second negative angle with the inner peripheral surface at a second spaced apart point. At least one of the first angle and the second angle may be 17.5 degrees or less.

The length from the front end to the rear end of the protrusion may be 50 to 100% of the length of the drum. The drum may have a flat front end band and a rear end band at front and rear ends, and the protrusion may be disposed between the front end band and the rear end band.

The protrusion may be integrally formed with the drum. The drum is processed by a metal plate of stainless steel (stainless steel), the thickness may be 0.4 to 0.6mm.

Alternatively, the protrusion may be made of synthetic resin and combined with the drum.

The drum may have a diameter of 484 mm, and a height of the protrusion protruding into the drum may be 10.0 to 30.0 mm.

The diameter of the drum may be 515 mm, and the height of the protrusion protruding into the drum may be 10.6 to 30.9 mm.

The drum may have a diameter of 575 mm, and the height of the protrusion protruding into the drum may be 11.8 to 34.5 mm.

The diameter of the drum may be 590 mm, and the height of the protrusion protruding into the drum may be 12.1 to 35.4 mm.

In the control method of the washing machine of the present invention, the drum is continuously rotated by one or more revolutions in one direction at a speed set between 60 and 90 rpm so that the fabric is lifted up to a predetermined height by the protrusion and falls at least once. To control.

First, the washing machine of the present invention, even if the drum is rotated at a higher speed than in the prior art, the carriage does not stick to the drum, can be flowed in the drum has the effect that the washing force is improved.

In particular, even if the rotational speed of the drum is 60rpm or more, the laundry does not adhere to the drum to flow in the drum, there is an effect that can increase the wrapping speed by approximately 18% compared with the conventional.

In addition, since the fabric flows in the drum even while the drum is being rotated at a higher speed than in the related art, the friction force between the fabric and the drum is increased, thereby enhancing the rubbing effect.

1 is a side cross-sectional view of a washing machine according to an embodiment of the present invention.
FIG. 2 schematically illustrates a cross section of the washing tub shown in FIG. 1.
3 schematically illustrates a longitudinal section of the washing tub shown in FIG. 1.
4 is a cross-sectional view taken along the line IV-IV of FIG. 3.
5 is a graph showing the embedding speed according to the height of the protrusion.
6 is a view referred to to explain the correlation between the height of the protrusion and the side angle.
Figure 7 shows the flow of the fabric according to the rotational speed of the drum.

Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and those of ordinary skill in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

1 is a side cross-sectional view of a washing machine according to an embodiment of the present invention. Referring to FIG. 1, a washing machine according to an embodiment of the present invention may include a casing 1 forming an outer appearance, a reservoir 3 disposed in the casing 1 and storing wash water, and rotating in the reservoir 3. It is installed so as to include a laundry tank 4 into which the laundry is put, and a motor 9 for rotating the laundry tank (4).

The washing tank 4 has a front cover 41 having an opening for entering and exiting laundry, a cylindrical drum 42 disposed substantially horizontally so that the front end is coupled to the front cover 41, and a rear end of the drum 42. It includes a rear cover 43 is coupled. The rotating shaft of the motor 9 may be connected to the rear cover 43 by passing through the rear wall of the reservoir 3. A through hole may be formed in the drum 42 so that water may be exchanged between the washing tub 4 and the tub 3.

The washing tub 4 is rotated about a horizontal axis. Here, the "horizontal" does not mean a geometric horizontal in a strict sense, and even when inclined at a predetermined angle with respect to the horizontal as shown in FIG. 1, the washing tank 4 is closer to horizontal than vertical. It is assumed that it is rotated about a horizontal axis.

In addition, the washing tank 4 includes a plurality of protrusions 20 provided on the inner circumferential surface of the drum 42. A plurality of protrusions 20 extend in the front-rear direction on the inner circumferential surface of the drum 42, these protrusions 20 are spaced apart along the circumferential direction, preferably, with respect to the center O of the drum 42 It is arranged at a constant angle (equivalent).

Between adjacent pairs of protrusions 20 selected arbitrarily (or randomly) from the plurality of protrusions 20, there is no protrusion higher than any one of the plurality of protrusions 20. In other words, no matter how the pair of adjacent protrusions 20 are taken, no structure protrudes higher than the protrusions 20 between them.

A plurality of embossing 425 may be provided on the inner circumferential surface of the drum 42. The embossing 425 is a protruding structure formed on the inner circumferential surface of the machine, and the height protruding into the drum 42 is lower than any of the plurality of the protruding portions 20. On the inner circumferential surface of the drum 42, there is no protrusion structure except at least one of the plurality of embossings 425 between a pair of adjacent adjacent protrusions arbitrarily selected among the plurality of protrusions 20.

Embossing 425 may be formed integrally with drum 42, and the plurality of embossing 425 need not be constant in size and / or height, as shown in FIG. A plurality of embossings 425 may be formed in which the size gradually increases or decreases in the longitudinal direction. The height of the embossing 425 is 5 mm or less.

On the other hand, the drum 42 is a metal plate of stainless steel (stainless steel), the thickness may be 0.4 to 0.6mm. The cylindrical drum 42 can be formed by rounding a rectangular metal sheet and joining (eg, welding) both ends to each other. The metal plate is preferably an STS430 series, but is not necessarily limited thereto.

A laundry inlet is formed on the front surface of the casing 1, and a door 2 for opening and closing the laundry inlet is rotatably provided in the casing 1. Inside the casing 1, a water supply valve 5, a water supply pipe 5, and a water supply hose 8 may be installed. When the water supply valve 5 is opened to supply water, the washing water passing through the water supply pipe 5 may be mixed with the detergent in the dispenser 14, and then supplied to the water storage tank 3 through the water supply hose 8.

The input port of the pump 11 is connected to the reservoir 3 by the discharge hose 10, the discharge port of the pump 11 is connected to the drain pipe (12). Water discharged from the reservoir 3 through the discharge hose 10 is pumped by the pump 11 and flows along the drain pipe 12, and then discharged outside the washing machine.

Figure 7 shows the flow of the fabric according to the rotational speed of the drum. Reference is now made to FIG. 7. While the drum 42 is being rotated, the forces acting on the fabrics introduced into the drum 42 are applied from the centrifugal force Fc, gravity Fg, and the protrusion 20 caused by the rotation of the drum 42. Lifting force (Fn).

As shown in FIG. 7A, when the drum 42 is rotated at a low speed, since the centrifugal force Fc is relatively small, the fabric is raised to a certain height by the protrusion 20, and the centrifugal force Fc ) And the support force (Fn) is unable to handle the gravity (Fg) is separated from the projection 20 and falls. This flow of cloth is defined as a rolling motion.

7 (b) is a state in which the rotational speed of the drum 42 is larger than that of FIG. 7 (a), and it is shown that the fabric falls after rising to a higher position. In particular, the position at which the gun falls is at least 90 degrees of rotation angle from the lowest point of the drum, and this flow of the gun is defined as a tumbling motion hereinafter.

If the rotational speed of the drum 42 further increases, it is ultimately rotated in a state in which it is attached to the drum 42 without falling even at the highest point of the carriage drum 42, as shown in FIG. The lowest value of the rotational speed of the drum 42, which can cause the foaming of the form as shown in FIG. 7C, is defined as the foaming speed Vf.

When the drum 42 does not have the protrusion 20, since the bearing force Fn is eliminated, only the centrifugal force Fc and the gravity Fg remain on the force acting on the fabric. In this case, the embedding speed vf can be obtained from an equilibrium equation that equals centrifugal force and gravity. Since the mass of the cloth is canceled on both sides of the equilibrium equation, the foaming speed Vf becomes a value dependent on the diameter of the drum irrespective of the mass of the cloth, and is a predetermined value that can be obtained by knowing the diameter of the drum.

By the way, when the protrusion part 20 is formed in the drum 42, since the bearing force Fn acts further, the wrapping speed Vf becomes low compared with the case where the protrusion part 20 is not applied generally. At this time, the embedding speed (Vf) will vary depending on the structure of the protrusions 20, but the drum 42 has a diameter of 24 to 27 inches (inch) and the height of the lifter (protrusions) 40mm or more in the conventional washing machine The speed Vf is about 55 rpm or less.

The washing force is determined by several factors such as flexing, friction, and drop of the gun. These factors are closely related to the rotational speed of the drum 42, and in particular, relative to the drop of the gun or to the drum, such as rolling or tumbling motion. Movement (or flow in the drum) is induced, but the higher the rotational speed of the drum 42 at this time is advantageous to enhance the washing force.

In this aspect, it is necessary to devise a way to increase the embedding speed Vf while rotating the drum 42 at a higher speed than in the related art, and the present invention provides a height h of the protrusion 20, that is, The height projecting inwardly of the drum 42) was lowered as compared with the prior art to reduce the bearing force Fn. The height h of the protruding portion 20 at this time is 2.0 to 6.0% of the diameter D as compared to the diameter 42 of the drum 42, and is approximately 10 to 30 mm in absolute value.

The control method of the washing machine according to an embodiment of the present invention can implement a rolling or tumbling motion while rotating the drum 42 at a higher speed than in the related art.

Specifically, when the protrusion height of the protrusions 20 is 2.0 to 6.0% of the diameter of the drum 42, the drum 42 is continuously rotated one or more revolutions in one direction at a speed set between 60 and 90 rpm, whereby the drum It is possible to at least once carry out the bubble inside the 42 by being raised to the predetermined height by the protrusion 20 and falling.

The set speed may be a speed at which a rolling motion is induced, and in this case, the cloth in the drum 42 rises to an angle of 90 degrees or less in the rotational direction of the drum 42 at the lowest point of the drum 42 and then falls.

Alternatively, the set speed may be a speed that causes tumbling motion. At this time, the cloth in the drum 42 rises to an angle of 90 degrees or more and 180 degrees or less in the rotational direction of the drum 42 at the lowest point of the drum 42, and then falls.

A controller (not shown) for controlling the rotation of the motor 9 may be provided, and the drum 42 may be rotated by the speed control of the motor 9 by the controller.

FIG. 2 schematically illustrates a cross section of the washing tub shown in FIG. 1. 3 schematically illustrates a longitudinal section of the washing tub shown in FIG. 1. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3. Reference is now made to FIGS. 2 to 4.

When viewed from the front of the drum 42, the protrusion 20 is longer in the longitudinal direction (or front and rear direction) of the drum 42 than the width of the drum 42 in the circumferential direction. These protrusions 20 are arranged symmetrically with respect to the center of the drum 42, in the embodiment three protrusions 20 are arranged at an isometric angle of 120 degrees with respect to the center of the drum 42, but is not necessarily limited thereto. .

The protrusion 20 may be integrally formed with the drum 42. For example, the protruding portion 20 can be formed by plastic working of the metal sheet. However, the present invention is not limited thereto, and in some embodiments, the protrusion 20 may be formed separately from the drum 42, and then coupled to the drum 42. In particular, in the latter case, the protrusion 20 may be made of synthetic resin.

On the other hand, in order to smoothly spread the fabric by expanding the contact area between the projection 20 and the fabric (or the area where the projection 20 exerts a bearing force Fn), the length of the projection 20 Should be appropriate, and in this aspect the present invention suggests that the length L1 from the front end to the rear end of the projection 20 is 50 to 100% of the drum L length L0. In particular, even when the length L1 of the protrusion 20 is close to 50% of the length L0 of the drum 42, the protrusion 20 may be disposed to cover the front and rear of the drum 42. It is preferable to provide the projection 20 so that the front end of the 20 is at a position spaced rearward from the front end of the drum 42.

Specifically, the drum 42 has a flat front band portion 42a and a rear band portion 42b formed at the front end and the rear end, respectively, and the protrusions 20 may be disposed between the front end band 42a and the rear end band 42b. have.

On the other hand, referring to Figure 4, the projection 20, when viewed from the front, the first side portion that forms a positive first angle (+ θ) with the inner peripheral surface at the first point (P1) on the inner peripheral surface of the drum 42 And a second side surface portion 22 forming a negative second angle (−θ) with the inner circumferential surface at a second point P2 circumferentially spaced from the first point P1 on the inner circumferential surface. Can be. Here, at least one of the first angle and the second angle is 17.5 degrees or less. Hereinafter, angle (theta) is defined as a side angle.

In the embodiment, the first side portion 21 and the second side portion 22 are symmetrical, and the first angle and the second angle have the same size, but are not necessarily limited thereto.

5 is a graph showing the embedding speed (Vf) according to the height of the protrusion. 6 is a view referred to to explain the correlation between the height of the protrusion and the side angle. First, as described above, FIG. 5 shows that the higher the height h of the protrusion 20 is, the lower the wrapping speed Vf is. By the way, when the height h of the protrusion 20 is 5mm or less, the lapping speed Vf may be high, and thus washing performance may be good, but in reality it is not.

When the height h of the protrusion 20 is 5 mm or less, the support force Fn of the protrusion 20 is too small, so that the cloth almost rolls in place in a state where the drum 42 does not reach the embedding speed Vf. It shows a behavior of moving only up and down within a very small angle of rotation tool, and suddenly starts to stick to the drum 42 when the wrapping speed Vf is reached. The flow of this type of cloth is intensified as the volume is small, and the washing power is not good because the fall or flexion of the cloth is not induced smoothly. For this reason, the height h of the protrusion 20 should be at least greater than 5 mm, preferably at least 10 mm.

The height h of the protruding portion 20 is preferably 30 mm or less, and in this case, the embedding speed Vf becomes about 65 rpm or more, and about 18% of the embedding is compared with 55 rpm when the conventional height is 40 mm. You can expect an increase in speed.

For each diameter D of the drum 42, preferred values of the lower limit LSL and the upper limit USL of the height h of the protrusion 20 are as follows. Here, the diameter of the drum 42 may be any of an inner diameter, an outer diameter, or an intermediate value between the inner diameter and the outer diameter of the drum 42.

Drum Diameter (D (mm)) LSL (mm) USL (mm) 484 10.0 30.0 515 10.6 30.9 575 11.8 34.5 590 12.1 35.4

Meanwhile, referring to FIG. 6, it is understood that the rolling or tumbling of the fabric is not induced in the area A where the height h of the protrusion 20 is smaller than 5 mm and the side angle θ is smaller than 17.5 degrees. Therefore, even when the height h of the protrusion 20 is 5 mm, the side angle θ is preferably at least 17.5 mm so as to cause rolling or tumbling. The area B shown in FIG. The height h of 5) is 5 mm or more and the side angle θ is 17.5 or more, indicating that the rolling or tumbling motion of the fabric can be caused in this area. The height of the protrusions 20, where performance can be further enhanced, is preferably at least 10 mm.

On the other hand, the curve shown by the dotted line in Figure 6 connects the threshold values of the side angle (θ) that can cause rolling or tumbling.

On the other hand, the control method of the laundry treatment machine according to an embodiment of the present invention, it is possible to implement as a processor readable code on a processor-readable recording medium. The processor-readable recording medium includes all kinds of recording devices that store data that can be read by the processor. Examples of the processor-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage device, and the like, and may also be implemented in the form of a carrier wave such as transmission over the Internet. . The processor-readable recording medium can also be distributed over network coupled computer systems so that the processor-readable code is stored and executed in a distributed fashion.

Although the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the above-described specific embodiments, it is intended in the technical field to which the invention belongs without departing from the spirit of the invention claimed in the claims. Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

Claims (13)

In the washing machine configured to rotate the cylindrical drum to be fed around the horizontal axis,
It extends in the longitudinal direction on the inner circumferential surface of the drum, and includes a plurality of protrusions spaced along the circumferential direction,
The protrusion,
The height projecting inwardly of the drum is 2.0 to 6.0% of the diameter of the drum,
And a protrusion structure higher than any one of the plurality of protrusions does not exist between an adjacent pair of protrusions arbitrarily selected among the plurality of protrusions on the inner circumferential surface of the drum. The method of claim 1,
The drum,
Further comprising a plurality of embossings formed on the inner circumferential surface lower than any of the plurality of protrusions,
And a protrusion structure on the inner circumferential surface of the drum, between at least one of the plurality of embossings, between a pair of adjacent protrusions arbitrarily selected from among the plurality of protrusions. The method of claim 2,
The height of the embossing is 5mm or less washing machine. The method of claim 1,
The protrusion,
A first side portion which, when viewed from the front, forms a first positive angle with the inner circumferential surface at a first point on the inner circumferential surface of the drum; And
When viewed from the front, comprising a second side portion which makes a negative second angle with the inner circumferential surface at a second point circumferentially spaced from the first point on the inner circumferential surface,
At least one of the first angle and the second angle is 17.5 degrees or less. The method of claim 1,
The length from the front end to the rear end of the protrusion,
Washing machine 50 to 100% of the length of the drum. The method of claim 5, wherein
The drum,
Flat front and rear band sections are formed at the front and rear ends, respectively.
The protrusion,
Washing machine disposed between the front end band portion and the rear end band portion. The method of claim 1,
The protrusion,
Washing machine is formed integrally with the drum. The method of claim 7, wherein
The drum is a machined sheet metal of stainless steel (stainless steel), the washing machine having a thickness of 0.4 to 0.6mm. The method of claim 1,
The drum is made of stainless steel,
The protrusion,
Washing machine made of synthetic resin and combined with the drum. The method of claim 1,
The protrusion,
Washing machine has a height of 10 to 30mm protruding into the drum. A cylindrical drum into which the cloth is inserted is rotated about a horizontal axis, and extends in the front and rear direction on the inner circumferential surface of the drum, and includes a plurality of protrusions spaced along the circumferential direction, and the protrusions protrude inwardly of the drum. In the control method of the washing machine, the height is 2.0 to 6.0% of the diameter of the drum,
And continuously rotating the drum one or more revolutions in one direction at a speed set between 60 and 90 rpm so that the fabric is carried up and dropped by a protrusion to a predetermined height at least once. The method of claim 11,
The set speed is,
And a fabric in the drum is set to rise and fall from the lowest point of the drum to an angle of 90 degrees or less in the rotational direction of the drum. The method of claim 11,
The set speed is,
The control method of the washing machine is set to rise and fall from the lowest point of the drum to the angle of 90 degrees or more and 180 degrees or less in the rotational direction of the drum.

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