EP1502987A1

EP1502987A1 - Washing machine

Info

Publication number: EP1502987A1
Application number: EP04252397A
Authority: EP
Inventors: Hyun Sook Kim; Ki Hun Joo; Jung Ran Jung; Ki Su Lee; Hyun Mu Lee; Uk Jin Jang
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2003-07-31
Filing date: 2004-04-23
Publication date: 2005-02-02
Also published as: KR20050014506A; CN100339531C; US20050022319A1; CN1580367A

Abstract

A drum washing machine and method of controlling the drum washing machine, which sufficiently dissolves a detergent by reciprocating water and the detergent contained in a lower portion of a water tub between the water tub and a detergent dissolution pipe, thus improving solubility of the detergent. Accordingly, a washing time may be decreased and laundry may be washed more cleanly. The drum washing machine and the method of controlling the drum washing machine of the present invention sufficiently dissolves the detergent in water and then efficiently sprays a detergent solution, in which the detergent dissolves in water, on an upper part of laundry, thus increasing utilization of the detergent. Therefore, a washing time is decreased and washing performance is improved.

Description

The present invention relates, in general, to a drum washing machine comprising a fixed water tub and a rotary water tub rotatably housed within said fixed water tub and to a method of controlling the drum washing machine.
In a conventional drum washing machine comprising a rotating tub within a fixed water tub, the washing process is executed after detergent is fed into the rotary tub together with a set amount of water, and the detergent dissolves in the water and separates stains from laundry by means of alternating opposite directional rotation of the rotary tub.
However, in the conventional drum washing machine, the fed detergent sinks to the bottom of the fixed water tub and dissolves in the water during the alternating opposite directional rotation of the rotary tub. In this case, it is difficult for the detergent to be sufficiently dissolved in the water and so detergent deposits remain in the water and, therefore, the laundry may not be washed clean. Furthermore, a long time is required to completely dissolve the detergent in the water which increases the washing time.
In addition, in the conventional drum washing machine, detergent solution, in which the detergent is dissolved in water, gradually disperses to an upper part of laundry from a lower part thereof by the alternating opposite directional rotation of the rotary tub. Therefore, it may take a relatively long time for this dispersion to occur, depending on the materials of the laundry, or the detergent solution may not sufficiently soak all of the way through the laundry, thereby increasing the washing time and deteriorating washing performance.
It is therefore an object of the present invention to provide a drum washing machine and method of controlling the drum washing machine, which substantially alleviates or overcomes the problems mentioned above.
Accordingly, the drum washing machine of the present invention is characterised by a detergent dissolving unit outside the fixed water tub operable to mix water and detergent drained from the fixed water tub.
A preferred embodiment preferably comprises a drain pipe for draining water from the fixed tub and a motor to drain water from the fixed tub through the drain pipe, the detergent dissolving unit comprises a pipe having a first end connected to the drain pipe. Conveniently, the other end of the pipe is disposed at an inlet to the rotary tub, and advantageously, is provided with a spray nozzle.
The detergent dissolving unit preferably comprises a dissolution member disposed in the pipe, the dissolution member defining a dissolution space formed by an enlarged diameter section of the pipe.
Conveniently, a valve is disposed between said first and second ends of the pipe to selectively open or close the flow passage from the drain pipe into the pipe.
A preferred embodiment includes a control unit to operate the pump according to preset ON/OFF periods to reciprocate the water and the detergent contained in the lower portion of the water tub between the water tub and the pipe and dissolution space.
The method of the present invention is characterised by the step of draining water and detergent from the fixed water tub into a detergent dissolving unit outside the fixed water tub to mix water and detergent supplied to the fixed water tub.
In a preferred embodiment, the washing machine includes a drain pipe for draining water from the fixed water tub and a drain pump to drain water from the fixed water tub through the drain pipe, and the method preferably includes the step of switching the drain pump on and off repeatedly to cause water and detergent to flow backwards and forwards between the fixed water tub and the detergent dissolving unit.
The detergent dissolving unit conveniently comprises a pipe having one end attached to the drain pipe and the other end disposed at an inlet to the rotary rub, the method preferably including the step of operating the drain pump to pump water through the detergent dissolving unit and into the rotary tub through the other end of the pipe.
The drum washing machine control method may further include rotating the rotary tub, and feeding a detergent solution in which the detergent dissolves in water by the reciprocation, into the rotary tub while the rotary tub is rotated.
The drum washing machine control may further include spraying a certain amount of water into the rotary tub after feeding the detergent solution into the rotary tub.
The drum washing machine control method may further include rotating the rotary tub in opposite directions at a low speed after feeding the detergent solution.
A preferred embodiment of the present invention will now be described, with reference to the accompanying drawings, in which:
Figure 1 is a perspective view showing an internal structure of a drum washing machine according to an embodiment of the present invention;
Figure 2 is a control flowchart of a method of controlling the drum washing machine of figure 1 according to the present invention;
Figures 3A and 3B are views showing a process of dissolving a detergent;
Figure 4 is a view showing a process of spraying clean water into a rotary tub while rotating the rotary tub at a high speed before spraying a detergent solution; and
Figure 5 is a view showing a process of spraying the detergent solution into the rotary tub.
Referring now to Figure 1 showing a drum washing of the present invention, first and second water feed pipes 12 and 13 are provided to allow water flowing from an external water supply pipe to selectively flow into a fixed water tub 10 or a rotary tub 11.
The first water feed pipe 12 is connected to the water tub 10, and the second water feed pipe 13 is connected to an inside of the rotary tub 11. The first and second water feed pipes 12 and 13 include first and second water feed valves 14 and 15 respectively mounted therein to allow water to selectively flow into the water tub 10 or the rotary tub 11.
In the first water feed pipe 12, a detergent container 16 is disposed between the first water feed valve 14 and the water tub 10 to allow both water and detergent to be fed into the water tub 10.
A spray nozzle 13a is provided at an end of the second water feed pipe 13 to spray water into the rotary tub 11. Therefore, the drum washing machine is constructed so that both water and detergent can be fed into the water tub 10 through the first water feed pipe 12 and only water can be sprayed into the water tub 10 through the second water feed pipe 13.
A drain pipe 17 is mounted on a bottom of the water tub 10 that, in use, contains water and detergent that has flowed into the water tub 10 through the first water feed pipe 12. A drain pump 18 and a drain valve 19 are mounted at the drain pipe 17 to pump the water and the detergent contained in a lower portion of the water tub 10.
A detergent dissolution pipe 20 is branched from the drain pipe 17 between the drain pump 18 and the drain valve 19, the other end thereof is connected to an inlet of the rotary tub 11. A spray nozzle 20a is formed at said other end of the detergent dissolution pipe 20 to spray a detergent solution into the rotary tub 11. A cylindrical detergent dissolution space 20b having a diameter greater than that of the detergent dissolution pipe 20 is formed at a centre portion of the detergent dissolution pipe 20 and a detergent dissolution pipe valve 21 is provided at the detergent dissolution pipe 20 to prevent water from flowing into the detergent dissolution pipe 20 when the water tub 10 is being drained.
A reversible motor (not shown) is mounted on the rotary tub 11 and is operable to rotate the rotary tub 11 in both forward and reverse directions. A water level sensor (not shown) is mounted in the rotary tub 11 to sense a level of water contained in the rotary tub 11.
The first and second water feed valves 14 and 15, the motor, the drain pump 18, the drain valve 19 and the detergent dissolution pipe valve 21 are all electrically connected to a control unit that performs an entire control operation.
Referring now to the control flowchart of Figure 2, the first water feed valve 14 is turned on for a certain period of time to allow water and detergent to be fed into the water tub 10 in operation 100. However, since the water flowing from the water supply pipe has run over the detergent in the detergent container 16, the detergent may not be sufficiently dissolved in the water and a considerable amount of detergent may remain in a solid state in the water. Furthermore, as will be described later, the rotary tub 11 is rotated in opposite directions after a predetermined amount of water has been fed into the water tub 10, which causes the detergent solution to rapidly soak through a lower part of laundry that is in contact with an inner wall of the rotary tub 11. However, it takes a relatively long time for the detergent solution to sufficiently soak through the centre part of the laundry remote from the inner wall of the rotary tub 11.
Therefore, to solve the problems mentioned above, a detergent dissolving process, which sufficiently dissolves the detergent in the water is required. Additionally, a detergent spraying process, which directly sprays the detergent solution into the rotary tub is also required.
The detergent dissolving process is executed in operation 110 in which the drain pump 18 is operated according to preset ON/OFF periods thereby repeating the operations illustrated in Figures 3A and 3B. Accordingly, the detergent and the water are forced to reciprocate between the water tub 10 and the detergent dissolution pipe 20, thereby agitating and mixing the water and the detergent.
More specifically, during the ON period of the drain pump 18, the water and the detergent contained in the lower portion of the water tub 10 are pumped into the detergent dissolution space 20b of the detergent dissolution pipe 20 as shown in Figure 3B. On the contrary, during the OFF period of the drain pump 18, the water and the detergent contained in the detergent dissolution pipe 20 flow back to the lower portion of the water tub 10 as shown in Figure 3A. Therefore, the shaking and mixing action enhances the dissolution of the detergent in the water. In this process, the ON period of the drain pump 18 is preset such that the water contained in the detergent dissolution pipe 20 is prevented from overflowing from the detergent dissolution space 20b into the rotary tub 11.
After the detergent dissolving process is executed, the first water feed valve 14 is turned on to feed a preset amount of water in operation 120 wherein water flowing from the water supply pipe is fed into the water tub 10 through the first water feed pipe 12 and gradually fills the rotary tub 11. In addition, to uniformly soak the laundry in water, in operation 130, the motor used to drive the rotary tub is operated in forward and reverse directions at a preset speed to alternately rotate the rotary tub 11 in opposite directions at a low speed.
Thereafter, in operation 140, the rotary tub 11 is rotated at a high speed. As a result, centrifugal force causes the laundry to be pressed against the inner wall of the rotary tub 11 thus forming a cavity in the centre of the rotary tub 11. During operation 140, the speed of rotation of the motor is higher than that of the motor during washing. The direction of rotation of the motor is preset according to the mounting position of the detergent solution spray nozzle 20a to most efficiently spray the detergent solution on the upper part of the laundry. For example, the spraying direction of the detergent solution spray nozzle 20a and the rotating direction of the rotary tub 11 are set to correspond to each other. If the detergent solution spray nozzle 20a is mounted at the right portion of the rotary tub 11 and faces the left portion of the rotary tub 11, the rotary tub 11 is rotated counterclockwise.
After the rotary tub 11 is rotated at a high speed to form the cavity operation 140, the second water feed valve 15 is turned on again in operation 150 thereby spraying a predetermined amount of water (1 to 2 litres) on the upper part of the laundry, as shown in Figure 4. One reason for performing the above operation is to prevent stains from forming on the laundry when the detergent solution is sprayed into the rotary tub 11, due to the upper part of the laundry not being sufficiently soaked with water compared to the lower part of the laundry which has come into contact with the inner wall of the rotary tub 11. Additionally, the weight of the laundry is increased due to the added water, and so when the rotary tub 11 is rotated at a high speed, the size of the cavity is increased due to the increased weight of the laundry generating larger centrifugal force.
After a predetermined amount of clean water is sprayed into the rotary tub 11 in operation 160, the drain pump 18 is turned on for the ON period while the rotary tub 11 is rotated at a high speed, thus spraying the detergent solution contained in the detergent dissolution space 20b on the upper part of the laundry within the rotary tub 11 for a certain period of time (for example, 1 minute) as shown in Figure 5. Accordingly, the detergent solution is quickly and sufficiently soaked through and absorbed into the upper part of the laundry. Therefore, the washing time is shortened and utilization of the detergent is increased, thus improving washing performance.
A later washing process may be executed but the rotation at high speed of the rotary tub 11 in operation 160 causes the laundry to become massed and entangled. Therefore, operation 170 is performed in which the rotary tub 11 is rotated in opposite directions at a low speed, thus forming a water current to disentangle the laundry. Accordingly, the massed and entangled laundry is loosened and released thereby reducing wrinkles, and a washing process can then be executed.
The above control flowchart describes a case where the water feeding process is executed after the detergent dissolving process. However, the present invention is not limited to the above embodiment, and the detergent dissolving process and the water feeding process may be executed simultaneously.
As is apparent from the above description, the present invention provides a drum washing machine and method of controlling the drum washing machine, which increases the solubility of a powdered detergent by more effectively dissolving the powdered detergent in water, thus decreasing a washing time and washing laundry more effectively.
Furthermore, the present invention is advantageous in that it enables a detergent solution to more effectively soak through the entire laundry load thus increasing the utilization of a detergent and consequently improving washing performance.
The present invention is also advantageous in that a detergent solution is sprayed on laundry, after a rotary tub is rotated at a high speed to press the laundry into contact with an inner wall of the rotary tub thereby forming a cavity so that the detergent solution can be more efficiently sprayed onto the upper part of the laundry.
In addition, the present invention provides the added advantage that the detergent solution is sprayed on laundry after the laundry is soaked with water, thereby preventing the laundry from being stained with the detergent solution.
Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles of the invention, the scope of which is defined in the claims and their equivalents hereafter.

Claims

A washing machine comprising a fixed water tub and a rotatable tub housed within said fixed water tub characterised by a detergent dissolving unit outside the fixed water tub operable to mix water and detergent drained from the fixed water tub.
A washing machine according to claim 1, comprising a drain pipe for draining water from the fixed tub and a motor to drain water from the fixed tub through the drain pipe, the detergent dissolving unit comprises a pipe having a first end connected to the drain pipe.
A washing machine according to claim 2, wherein the detergent dissolving unit comprises a dissolution member disposed in the pipe, the dissolution member defining a dissolution space formed by an enlarged diameter section of the pipe.
A washing machine according to claim 2 or claim 3, wherein a valve is disposed between said first and second ends of the pipe to selectively open or close the flow passage from the drain pipe into the pipe.
A washing machine according to any of claims 2 to 4 wherein the other end of the pipe is disposed at an inlet to the rotatable tub.
A washing machine according to claim 5 wherein the second end of the pipe is provided with a spray nozzle.
A method of controlling a drum washing machine comprising a fixed water tub and a rotatable tub housed within the fixed water tub, characterised by the step of draining water and detergent from the fixed water tub into a detergent dissolving unit outside the fixed water tub to mix water and detergent supplied to the fixed water tub.
A method according to claim 7, wherein the washing machine includes a drain pipe for draining water from the fixed water tub and a drain pump to drain water from the fixed water tub through the drain pipe, the method including the step of switching the drain pump on and off repeatedly to cause water and detergent to flow backwards and forwards between the fixed water tub and the detergent dissolving unit.
A method according to claim 8 wherein the detergent dissolving unit comprises a pipe having one end attached to the drain pipe and the other end disposed at an inlet to the rotary rub, the method including the step of operating the drain pump to pump water through the detergent dissolving unit and into the rotary tub through the other end of the pipe.
A drum washing machine comprising a water tub including a lower portion, a rotary tub rotatably provided in the water tub and a detergent dissolving unit to dissolve a detergent, initially contained in the lower portion of the water tub in water initially contained in the water tub, outside the water tub and provided with a first end, which is connected to an inside of the water tub.
The drum washing machine according to claim 10 wherein the detergent dissolving unit comprises a detergent dissolution pipe having a first end connected with the inside of the water tub and a second end extended outside of the water tub and a pump to pump the water and the detergent contained in the lower portion of the water tub to the detergent dissolution pipe.
The drum washing machine according to claim 11 wherein the detergent dissolving unit comprises a control unit to operate the pump according to preset ON/OFF periods to reciprocate the water and the detergent contained in the lower portion of the water tub between the water tub and the detergent dissolution pipe.
The drum washing machine according to claim 11 wherein the detergent dissolving unit further comprises a detergent dissolution space having a diameter greater than that of the detergent dissolution pipe formed at the detergent dissolution pipe.
The drum washing machine according to claim 11 wherein the second end of the detergent dissolution pipe is provided at an inlet of the rotary tub.
The drum washing machine according to claim 14 wherein the detergent dissolving unit further comprises a spray nozzle provided at the second end of the detergent dissolution pipe.
The drum washing machine according to claim 11 wherein the detergent dissolving unit further comprises a valve mounted at the detergent dissolution pipe to selectively open and close a flow passage.
A method of controlling a drum washing machine, the drum washing machine having a water tub, a rotary tub, and a detergent dissolving unit provided outside of the water tub, the method comprising feeding water and a detergent into the water tub, and reciprocating the detergent and the water between the water tub and the detergent dissolving unit to dissolve the detergent.
The drum washing machine control method according to claim 17 further comprising rotating the rotary tub, and feeding a detergent solution, in which the detergent dissolves in water by the reciprocation, into the rotary tub while the rotary tub is rotated.
The drum washing machine control method according to claim 18 further comprising spraying and feeding a certain amount of water into the rotary tub after feeding the detergent solution into the rotary tub.
The drum washing machine control method according to claim 18 further comprising rotating the rotary tub in opposite directions at a low speed after completely feeding the detergent solution.
A drum washing machine comprising a cylindrical water tub to initially contain detergent and water, having a first end to be selectively opened and closed, a cylindrical rotary tub rotatably provided in the water tub and opened at a first end corresponding with the first end of the cylindrical water tub and a detergent dissolving unit to dissolve the detergent and the water, provided outside of the water tub and provided with a first end connected to an inside of the water tub.
The drum washing machine according to claim 21 wherein the detergent dissolving unit comprises a detergent dissolution pipe having a first end connected with the inside of the water tub and a second end extended outside of the water tub.
The drum washing machine according to claim 22 wherein the detergent dissolving unit comprises a pump to pump the water and the detergent contained in the lower portion of the water tub to the detergent dissolution pipe.
The drum washing machine according to claim 23 wherein the detergent dissolving unit comprises a control unit to operate the pump according to the preset ON/OFF periods to reciprocate the water and the detergent contained in the lower portion of the water tub between the water tub and the detergent dissolution pipe.
The drum washing machine according to claim 21 wherein the detergent dissolving unit further comprises a detergent dissolution space, having a diameter greater than that of the detergent dissolution pipe formed at the detergent dissolution pipe.
The drum washing machine according to claim 21 wherein the second end of the detergent dissolution pipe is provided at an inlet of the rotary tub.
The drum washing machine according to claim 26 wherein the detergent dissolving unit further comprises a spray nozzle provided at the second end of the detergent dissolution pipe.
The drum washing machine according to claim 21 wherein the detergent dissolving unit further comprises a valve mounted at the detergent dissolution pipe to selectively open and close a flow passage.
A drum washing machine comprising a cylindrical water tub, to initially contain detergent and water having a first end to be selectively opened and closed, a cylindrical rotary tub rotatably provided in the water tub and opened at a first end corresponding with the first end of the cylindrical water tub and a detergent dissolving unit to increase a solubility of the detergent in the water, provided outside of the water tub, and provided with a first end connected to an inside of the water tub.
A drum washing machine comprising a cylindrical water tub, to initially contain detergent and water, having a first end to be selectively opened and closed, a cylindrical rotary tub rotatably provided in the water tub and opened at a first end corresponding with the first end of the cylindrical water tub, and a detergent dissolving unit provided outside of the water tub, to partially dissolve the detergent in the water outside of the water tub, and having a first end connected to an inside of the water tub.
A method of controlling a drum washing machine in which laundry is laundered, the drum washing machine having a water tub, a rotary tub in which the laundry is held, and a detergent dissolving unit provided outside of the water tub, the method comprising feeding water and a detergent into the water tub and dissolving the detergent into the water partially outside the water tub, effectively feeding the dissolved detergent to the laundry.
The drum washing machine control method according to claim 31 wherein the effective feeding further comprises rotating the rotary tub at a high speed.
The drum washing machine control method according to claim 31 further comprising reciprocating the rotary tub in the water tub to increase a dissolving speed of the detergent into the water.
The drum washing machine control method according to claim 32 further comprising spraying and feeding a certain amount of water into the rotary tub after feeding the detergent solution into the rotary tub.
The drum washing machine control method according to claim 32 further comprising rotating the rotary tub in opposite directions at a low speed after completely feeding the detergent solution.