WASHING MACHINE

• US 20080229790A1
• Filed: 03/19/2008
• Published: 09/25/2008
• Est. Priority Date: 03/20/2007
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Kim, Woo Young, Kim, Kyeong Hwan, Chang, Jin Ho, Jo, Il Hyeon
• Granted Patent: US 7,980,102 B2
• Time in Patent Office: Days
• US Class Current: 68/17R
• CPC Class Codes: D06F 33/37 of metering of detergents or additives
• CPC Class Codes: D06F 39/022 in a liquid state D06F39/024 takes precedence

Abstract

Disclosed is a washing machine, which prevents solidification of liquid detergent by rapidly recovering the liquid detergent left in a liquid detergent supply passage and a liquid detergent supply pump by forming a negative pressure differential by use of the liquid detergent supply pump for a set period of time after the supply of liquid detergent is finished.

Claims

1. A washing machine, comprising:

a washing machine housing;

a washing tub disposed in the washing machine housing; and

a liquid detergent supply pump configured to provide a positive pressure differential for supplying liquid detergent to the washing tub, and configured to provide a negative pressure differential for removing residual liquid detergent not supplied to the washing tub.

2. The washing machine of claim 1, further comprising a liquid detergent storage container that stores the liquid detergent,

wherein the liquid detergent supply pump provides a pressure differential between the liquid detergent storage container and the washing tub.

3. The washing machine of claim 2, further comprising a liquid detergent supply passage provided between the washing tub and the liquid detergent storage container, the liquid detergent being supplied to the washing tub through the liquid detergent supply passage.

4. The washing machine of claim 3, wherein the liquid detergent supply pump removes residual liquid detergent remaining in the liquid detergent supply passage by providing a negative pressure differential.

5. The washing machine of claim 1, further comprising a detergent supply unit positioned along a passage through which washing water is supplied to the washing tub, the washing water and detergent being mixed together in the detergent supply unit,

wherein the liquid detergent is supplied to the washing tub via the detergent supply unit.

6. The washing machine of claim 1, wherein the liquid detergent supply pump is operated to supply a predetermined amount of liquid detergent to the washing tub, corresponding to the amount of laundry in the washing tub, by providing a positive pressure differential, and is then operated to remove residual liquid detergent not supplied to the washing tub by providing a negative pressure differential for a predetermined period of time.

7. The washing machine of claim 1, wherein, while the liquid detergent supply pump provides a negative pressure differential, washing water in the washing tub is sucked to remove residual liquid detergent not supplied to the washing tub.

8. The washing machine of claim 1, wherein the liquid detergent supply pump comprises a rotary pump that provides a positive pressure differential during forward rotation and provides a negative pressure differential during backward rotation.

9. The washing machine of claim 3, wherein a passage blocker that prevents air from contacting the liquid detergent stored in the liquid detergent storage container is provided at one end of the liquid detergent supply passage.

10. The washing machine of claim 9, wherein the passage blocker is disposed at an end of the liquid detergent supply passage connected to the washing tub.

11. The washing machine of claim 9, further comprising a detergent supply unit positioned along a passage through which washing water is supplied to the washing tub, and forming a portion of the liquid detergent supply passage,

wherein the passage blocker is disposed at an end of the liquid detergent supply passage connected to the detergent supply unit.

12. The washing machine of claim 9, wherein the passage blocker includes a check valve.

13. The washing machine of claim 1, further comprising a support frame configured to support the washing machine housing.

14. The washing machine of claim 1, further comprising a liquid detergent storage container that supplies liquid detergent to the washing tub,

the liquid detergent storage container being disposed within the support frame.

15. The washing machine of claim 5, wherein the detergent supply unit includes a detergent box configure to receive powder detergent is therein.

16. The washing machine of claim 2, wherein the liquid detergent storage container includes plural containers, the washing machine further comprising a switching valve configured to switch between the liquid detergent storage containers for selecting the liquid detergent stored in any one of the liquid detergent storage containers for supply to the washing tub.

17. The washing machine of claim 16, further comprising a liquid detergent supply passage provided between the washing tub and the liquid detergent storage container, the liquid detergent being supplied to the washing tub through the liquid detergent supply passage,

the liquid detergent supply passage comprising:

a first supply passage connecting the switching valve to the washing tub; and

a second supply passage connecting the liquid detergent storage container to the switching valve.