METHOD FOR OPERATING A WASHING MACHINE, AND WASHING MACHINE

Abstract

A washing machine and method for operating a washing machine having a suds container for holding washing liquid, a non-ribbed drum rotatably mounted in the suds container for holding laundry, a motor for driving the drum, and an open or closed loop control device, wherein the method has a step for rearranging the laundry in the drum. The drum is caused to execute a right-left motion by means of the motor so as to cause a rocking motion of the laundry at a rocking frequency, the predetermined rocking amplitude of which is adjusted such that a laundry fall is implemented in which the laundry falls from a first region of the drum into a second region of the drum.

Claims

1. A method for operating a washing machine having a suds container for holding washing liquid, a non-ribbed drum rotatably mounted in the suds container for holding laundry, a motor for driving the drum, and an open or closed loop control device, wherein the method has a step for rearranging the laundry in the drum, in which the drum is caused to execute a right-left motion by means of the motor so as to cause a rocking motion of the laundry at a rocking frequency, the rocking frequency having a predetermined rocking amplitude which is adjusted such that a laundry fall is implemented in which the laundry falls from a first region of the drum into a second region of the drum.

2. The method according to claim 1, wherein the rocking frequency is adjusted in the range of from −50% to +20% of a calculated rocking frequency stored in the washing machine, wherein the calculated rocking frequency stored is calculated using the following formula (1), $\begin{array}{cc}f=\frac{\sqrt{\frac{g}{r}}}{2\pi }& \left(1\right)\end{array}$ where f is the predetermined rocking frequency, g is the gravitational constant=9.81 m/s.sup.2, and r is a drum radius of the non-ribbed drum.

3. The method according to claim 1, wherein the rocking frequency is adjusted such that the rotational speed has a triangular time curve.

4. The method according to claim 3, wherein the triangular time curve is implemented by accelerating the motor alternately with constant acceleration in portions.

5. The method according to claim 1, wherein the predetermined rocking amplitude is more than +/−90°.

6. The method according to claim 1, wherein the rocking amplitude is increased from zero to the predetermined rocking amplitude within a predetermined period of time.

7. The method according to claim 6, wherein the predetermined period of time is a first period of time which is up to 0.5 commuting periods, or a second period of time which is 1.0 to 2.0 rocking periods.

8. The method according to claim 1, wherein the predetermined rocking amplitude is maintained over a predetermined period of time.

9. A washing machine having a suds container for holding washing liquid, a non-ribbed drum which is rotatably mounted in the suds container for holding laundry, a motor for driving the drum, and an open or closed loop control device designed to execute the method according to claim 1.

10. The method according to claim 2, wherein the rocking frequency is adjusted to −30% of the calculated rocking frequency stored in the washing machine.

11. The method according to claim 1, wherein the predetermined rocking amplitude is in the range of from +/−90° to +/−150°.

12. The method according to claim 1, wherein the predetermined rocking amplitude is in the range of from +/−100° to +/−110°.

13. The method according to claim 7, wherein first period of time is up to 0.2 rocking periods.

14. The method according to claim 7, wherein the second period of time is 1.5 rocking periods.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] An embodiment of the disclosure is shown in the drawings in a purely schematic manner and will be described in more detail below. In the drawings:

[0023] FIG. 1 is a time curve of a rotational speed and an angle in a method according to the disclosure; and

[0024] FIG. 2 is a time curve of a rotational speed and an angle in a further method according to the disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 is a time curve of a rotational speed and an angle in a method according to the disclosure. The rotational speed curve over time is triangular. The triangular shape is achieved by alternating acceleration of the motor with constant acceleration in portions. The rotational speed is increased in an acceleration phase until it varies in the range of +/−150 rpm. Since the curve of the angle, i.e., the angle of rotation, represents the integral of the rotational speed curve, it runs almost sinusoidally due to the properties of the integration (attenuation of the higher frequency components −20 dB/decade).

[0026] A rocking amplitude predetermined for generating a fall of laundry is initially increased from zero to the predetermined rocking amplitude within a predetermined period of time. The predetermined period of time is a first period of time, which is, for example, 1.5 rocking periods. The first period of time represents the acceleration phase, in which a large part of the laundry is entrained without sliding as the drum rotates. As soon as the predetermined rocking amplitude, for example of approx. +/−100°, is reached, the laundry begins to fall. If the predetermined rocking amplitude is then maintained, the laundry will constantly rise and fall alternately on the right and left side of the drum, based on the operational set-up position of the washing machine.

[0027] FIG. 2 is a time curve of a rotational speed and an angle in a further method according to the disclosure. The time curves of rotational speed and angle shown in FIG. 2 correspond to the time curves shown in FIG. 1 with the difference that the predetermined period of time is a second period of time which is zero and the rotational speed of the drum is in the range of +/−100 rpm is varied, so that the acceleration phase described in relation to FIG. 1 is missing. In other words, at the beginning of the method, the laundry slides in the drum, so that at the beginning there is a short phase with surface friction between the drum and the laundry.