EP0924330A1 - Drum washing machine or laundry drier and method for washing and spinning the laundry in a washing machine or in a washing and drying machine - Google Patents

Abstract

The machine has a balancing device with at least one circular track (12) which co-rotates with the drum (2) and contains at least two freely moving weights (13). The weights are entrained in the track (12) in a drum speed range with a minimum value lower than the washing speed. A controller (6a-6d) is provided for controlling the drive motor (4) such that the drum (2) is accelerated to a spinning speed above the speed at which the washing and the drum are in contact when the center of gravity of the weights (13) lies in a preset range.

Description

The invention relates to a washing machine or a washer-dryer for washing and Throwing laundry with a drum, which is driven by a drive motor around a horizontal or inclined axis is rotatable. In addition, the invention relates to a method for Washing and spinning laundry in a washing machine or washer-dryer with a drum, which is driven by a drive motor around a horizontal or inclined axis is rotatable, with a balancing device consisting of at least one with the drum circumferential, annular raceway arranged concentrically to its axis of rotation, within which at least one weight is freely movable, and with means for taking away the weights in the track in a drum speed range, their minimum value is lower than the washing speed.

Acceleration occurs when wet laundry is spun in the aforementioned washing machines the drum to a speed above the feed speed at which the Laundry centrifugal force is greater than gravity. The laundry is distributed therefore more or less evenly on the drum shell, with it being particularly heavy or highly absorbent pieces of textile can cause unbalance. These imbalances generate vibrations, which in turn stress the bearings and break wiring harnesses and also cause noise.

Balancing systems are known for avoiding or reducing such imbalances. In the For example, EP 0 640 192 B1 describes a so-called ball balancer, in which Balls are freely movable within a track attached to the drum. When the drum rotates, these align with the laundry imbalance and compensate them up to the size of the total weight of the balls.

In addition to the ball balancer, similarly acting systems are known (DE 27 53 610 C2), at those weights on rollers in a track with the body to be balanced circulate.

With a horizontal axis of rotation of the body it must be ensured that the balls or rotating weights with the raceway and not due to their gravity in the lower one Roll off the area of the web. For this purpose, EP 0 640 192 B1 proposes the career fill with a material that due to the resistance it exerts (friction, viscous damping) takes the balls to the beginning of the rotation. Here is a viscous one Damping agents, especially oil, have proven their worth, since liquids with low viscosity do not produce the desired effect. Alternatively, DE 27 53 610 C2 describes a device which the weights with the help of springs below a predetermined speed and the associated centrifugal force fixed on the inner edge of the track.

The disadvantage of the balancing devices described above is that they are compensatory Effect only above the resonance frequency or critical speed of the system unfold in which the rotating body is stored (see, for example, Kellenberger: elastic balancing; Springer Verlag 1987; P. 402f). In the subcritical speed range, the existing Unbalance can even be increased. Therefore the main area of application is an automatic one Ball balancer on fast rotating machines with a constant speed above all occurring resonance frequencies. However, there is a desire to use the automatic Ball balancer, for example, when a washing machine spins up to be used with a horizontal or inclined axis of rotation. Both Amplitudes in the steady supercritical state as well as when driving through the Resonances can be reduced.

From the patent application that is considered to be state of the art pursuant to Section 3 (2) PatG 19718321.2-13 is a method for balancing the drum of a washing machine Known use of a ball balancer, in which the drum first to a speed is accelerated above the landing speed. Then the position becomes one trained laundry imbalance sensed. The viscosity of the damping agent is such dimensioned so that the balls roll freely in this speed range. Then will the drum is strong at a certain, previously determined position of unbalance and balls accelerated so that the balls are carried away. It should be achieved that Imbalance and center of gravity opposite each other and thus also when passing through the critical Compensate the speed range. The disadvantage of this method is the strong one Temperature dependence of the viscosity of the damping agent. This is especially true for Washing machines with different alkali temperatures between 20 ° C and 100 ° C one exact determination of the speed behavior of such damping means not possible.

As an alternative to the balancing systems described above, DE 196 14 721 A1 describes a Textile spinner described in which a weight on the drum as a fixed unbalance is arranged. By accelerating the drum from a position in which the Weight is in the 12 o'clock position, the laundry should be unbalanced specifically trained against the fixed unbalance and thus partially compensate for both unbalances. Is the laundry imbalance due to low filling of the drum or good distribution but only slightly, the drum is with the entire spin cycle Fixed unbalance A rotated, which leads to the consequences described elsewhere.

The invention thus poses the problem of a washing machine or a washer-dryer and a method for washing and spinning laundry in such an apparatus disclose, in which both in the subcritical and in the supercritical area a safe Reduction of the total imbalance of the drum is achieved.

According to the invention, this problem is solved by a washing machine or a washer-dryer with the features specified in claim 1 and by a method with the Claim 9 specified features solved. Advantageous refinements and developments the washing machine or washer-dryer result from the following Subclaims.

The advantages achievable with the invention result from the use of the weights in the subcritical range as fixed unbalance as well as in the supercritical range as dynamic Unbalance compensator. In the subcritical range, the gain of Imbalance avoided, in the supercritical area the possibility of low laundry imbalance is also avoided, for example through drainage.

In an advantageous further development of the drum washing machine, the means for taking the weights consist of a viscous damping means arranged in the track, the viscosity and the size of the weights being dimensioned such that the weights are entrained at the washing speed. As a result, a simply constructed ball balancer can be used, but when selecting the damping agent, it is only necessary to ensure that it is viscous enough even at high alkali temperatures up to 100 ° C to take the balls with it even at washing speeds around 50 min ^-1 .

Alternatively, fixing devices in the form of the cross section of the raceway can be reduced Locking devices are used. Such facilities are from program control adjustable and are therefore not subject to external temperature influences.

The acceleration of the drum from a washing speed below the application speed A spin speed above the application speed can be used in washing machines with a ball balancer and damping agent-filled track after a stopping time or slight swiveling the drum in which the balls are gravity to the lowest point of the track have dropped. As a result, the center of gravity of the balls is in the 6 o'clock position Career or drum, so that the position of the unbalance is known and therefore not needs to be sensed more.

Alternatively, means for sensing the position of the weights or the center of gravity can be used be used. This will, on the one hand, provide greater security the position of the fixed unbalance is reached, on the other hand the program run times are shortened.

It can, for example, be the signal component of a speed signal corresponding to the drum speed drum or drive motor. Optionally or additionally can also be a displacement or acceleration signal of the tub as a position transmitter be used. This makes use of the fact that the laundry freely moving in the drum below the feed speed and no stationary imbalances yet has trained. Thus, the only periodic fluctuations in speed, displacement and acceleration caused by the unbalance. Through suitable signal analysis, e.g. Filtering of the aforementioned signals can thus be carried out in a simple manner and using already existing sensors (motor control, determination of the laundry weight) the position the center of gravity and the resulting unbalance become.

In another embodiment of the invention, it is possible to make the balls from one Manufacture material with ferromagnetic properties and its location by a fixed Determine magnetic sensor. This does require additional resources, but it is a faster and possibly more precise determination of the position of the center of gravity is possible. In addition, information about the time of the imbalance-related alignment of the Bullets are obtained.

Figur 1

eine Schemaskizze einer erfindungsgemäß ausgebildeten Waschmaschine

Figur 2a

eine Waschmaschinentrommel mit Kugelauswuchter und Bremselementen

Figur 2b

einen Teilschnitt aus Figur 2a entlang der Linie A-A

Figur 3

ein Drehzahl-Zeit-Diagramm vor und nach der Filterung durch eine Rechnerschaltung (6c)

Figur 4a,b

Drehzahlprofile

An embodiment of the invention is shown purely schematically in the drawings and is described in more detail below. It shows

Figure 1

a schematic sketch of a washing machine designed according to the invention

Figure 2a

a washing machine drum with ball balancer and brake elements

Figure 2b

a partial section of Figure 2a along the line AA

Figure 3

a speed-time diagram before and after filtering by a computer circuit (6c)

Figure 4a, b

Speed profiles

FIG. 1 shows the parts essential for the invention in a schematic diagram Washing machine. The washing machine designed according to the invention has a tub (1), in which a drum (2) for receiving laundry (3) is rotatably mounted. Of the The drum (2) is driven by a motor (4), the power transmission by a V-belt (5). The speed of the motor can be controlled in a known manner by a in the microprocessor control (6) the washing machine integrated motor controller (6a) program and can be set depending on the condition.

The tub is swinging on springs (7) in the housing (8) and becomes Damping of these vibrations in the lower area by shock absorbers (9) compared to Supported base (10). To further dampen the vibrations are on the tub (1) Additional weights (11) arranged so that it passes through the critical Speed range does not strike the housing (8).

So-called ball balancers are used as balancing systems in the drum cap and the drum base (12; 13) are used, wherein for producing the annular raceways (12) an inexpensive deep-drawing process is used. In these careers (12) are individual Balls (13) arranged as weights and can freely in the circumferential direction of the drum move. To ensure maximum compensation, each track (12) must be in tightest packing can be filled with balls in a given angular range. By Setting the size and number of balls (13) can cause an imbalance in the order of magnitude of their total weight are generated and thus also compensated.

So that the gravity acting on the balls (13) is overcome at a desired rotational speed and the balls (13) are carried along by the raceway (12) in the case of a horizontal axis of rotation, this is filled with a viscous damping means (14), oil being advantageously used . Without this damping means (14), the balls (13) would only be subject to rolling friction and thus roll off at the lowest point in the raceway (12) without developing their compensatory effect. An oil with a very low viscosity is used, so that it is ensured that the balls (13) are taken along at washing speeds of around 50 min ^-1 . They then generate a fixed unbalance A rotating around the drum in the subcritical range. As they pass through the critical speed range, they are distributed in order to fully or at least partially compensate for the total unbalance C of the drum (2) consisting of the laundry unbalance B and the fixed unbalance A.

A displacement sensor (15), arranged parallel to a shock absorber (9) or integrated in it, determines the weight-dependent lowering of the tub and sends a corresponding one Signal to a computer circuit (6b) integrated in the microprocessor control (6). The on the fixed unbalance A acting centrifugal force vectorially overlaps the weight, so that the weight signal periodic fluctuations with the frequency of the drum speed is exposed. During the washing process it is generated by the rotation of the drum raised and falling laundry additional vibrations in a wide frequency range. The computer circuit filters the weight signal in a known manner Drum speed corresponding frequency range and determines the position of the Fixed unbalance A. Instead of the displacement sensor (14), for example, one from DE 19522393 A1 known acceleration sensor can be used. In addition or as an alternative to this A further computer circuit (6c) can determine the position of the fixed unbalance A by method Evaluation of the fluctuations of a speed-dependent signal (motor current, slip ...) or determine the speed yourself (with a tachometer generator (15)). Here, too, one in the Computer circuit (6c) integrated filter the frequency range corresponding to the drum speed extract. With the same procedure, the location and size of the Laundry unbalance B and the total unbalance C can be determined. Figure 3 shows the speed signal of the tachometer generator at washing speed and the filtered unbalance signal at a rotation of the drum at a speed. Depending on the calculated unbalance position An evaluation circuit (6d) influences the motor controller (6a) and thus the speed curve the drum (2).

Another possibility for determining the position of the balls (13) consists of these to produce a material with ferromagnetic properties and a fixed magnetic sensor (not shown) to be arranged, for example, on the tub (1). The Field distortion sensed by non-magnetized spheres in a constant magnetic field.

Figures 2a and b show an embodiment of a ball balancer, in which a Filling the track (20) with oil can be omitted. The ball balancer shown has an annular raceway (20) in which individual balls (24) are arranged as weights are. These can be in the circumferential direction of any body to be balanced (not shown) move freely. To ensure maximum compensation, each Raceway (20) in the densest packing in an angular range α ≈ 180 ° filled with balls (24) become. This can cause an imbalance for a given size and number of balls (24) of 1 kg, for example, and thus also be compensated.

An elastic hose (22) is provided on the inner surface (21) of the raceway (20) as a fixing device. arranged, which can be set by the microprocessor control (not shown) Pump device (23) can be filled with air or another medium. This will the cross section of the raceway (20) is reduced and the balls (24) are fixed in their position. The hose (22) can be subdivided, the individual segments (22a, 22b, 22c) then can be filled by separate pump devices (23a, 23b, 23c). This way you can initially a single segment (22b) is inflated at the end of the spinning process then the balls collect. You can then pump up the rest Segments (22a, 22c) are fixed. This ensures that the balls (24) are in the tightest Pack close together and create the greatest possible unbalance. After this Passing through the critical speed range, the hose (22) is relieved of pressure, whereby the balls (24) are freely distributed and the total imbalance of the drum (2) completely or at least partially compensate.

As an alternative to using several segments (22a, 22b, 22c), when using one continuous hose (22) and a single pumping device (23) the hose (22) Relieve pressure before spinning and stop the drum (2). Hereby the balls (24) collect due to gravity in the lower part of the track (20) and can then be tightly packed together by inflating the tube (22) in the densest packing be fixed horizontally.

By fixing the balls in the subcritical area, in addition to the unbalance compensation a reduction in their rolling noises can be achieved. For further noise reduction and in order to keep wear to a minimum, the track of ball balancers can be used Mechanically compact rolling or embossing. Other procedures by which the career for the weights are hardened, for example a hard surface surface coating or cold compression is also possible. In addition to the running noises This avoids excessive stress at high speeds.

The mode of operation of the arrangement according to FIG described:

After the washing process, the alkali is first pumped out. Then the Drum (2) stopped for a holding time or swiveled slightly. This is dimensioned that the balls (13) sink due to gravity into the deepest area of the raceway (12) can. The drum (2) is then further rotated at the washing speed.

Alternatively or in addition to the stopping time, the position of the center of gravity of the ball, which is the Represents the center of a fixed unbalance A, determined by one of the computer circuits (6b, 6c) become.

In both cases it can be assumed that the microprocessor control (6) the position of the Fixed unbalance A now knows and based on a speed-proportional signal by counting the Drum rotations via the pulses from the tachometer generator also for the following program sequence can calculate.

If the fixed unbalance A is now in a previously defined position with respect to the focus of the laundry, d. H. to the point where statistically the largest accumulation of laundry (3) takes place, the drum (2) quickly reaches a speed above the application speed accelerates. The laundry (3) is not evenly distributed due to the rapid acceleration on the drum jacket, but there remains a large proportion in the place where it Time of the onset of acceleration. This forms against the Fixed unbalance A from laundry unbalance B, so that these unbalances are partially compensated for. With further acceleration of the drum and after passing through the critical Speed range, the balls are distributed according to the physical initially described Law and completely compensate for the unbalance.

Experience has shown that the point at which statistically the largest amount of laundry is present is when the drum is turned to the right between the 7 and 9 o'clock position. It depends on the type and weight of the laundry and on the washing speed. In addition, the initial acceleration of the spin profile must be taken into account, since the laundry (3) behaves as an inert mass and therefore does not follow the drum immediately when the speed increases. Depending on the load and the type of laundry, the control system decides which spin method is selected based on predefined values. The parameters start speed of acceleration, acceleration and spin-on angle are varied. Figures 4a and 4b show an example of a speed profile with low initial acceleration (Fig. 4a) and a profile with a sudden passage of the applied speed n ₂ (Fig. 4b).

The washing speed n ₁ and the initial acceleration are known to the microprocessor control (6) as manipulated variables, the weight of the laundry (3) can be measured with the displacement sensor (15). The type of laundry can be determined from its suction behavior, which in turn can be determined with the displacement sensor (15) or with a level sensor not shown in the drawings. Depending on the aforementioned variables, the microprocessor control determines a position of the fixed unbalance A, from which acceleration then takes place. Such a method can generally be used for fixed unbalances, even if these are generated by stationary weights on the drum.

The acceleration is carried out initially until reaching a spin speed n _3, n ₂ above the settling speed, but is _crit below the critical speed range .DELTA.n. This first spin speed n ₃ is kept constant by the motor control for a time phase t ₂ - t ₃ in which the size and position of the unbalances A and B or the resulting total unbalance C is determined again. It is checked whether the prescribed placement of the laundry with respect to the fixed unbalance A was successful and the unbalances A and B are exactly opposite. In addition, it must be ensured that the overall imbalance C does not exceed a maximum value, which may occur .DELTA.n _crit inadmissible vibration when passing through the critical speed range. If these conditions are met, the speed can be increased in a known manner until the final spin speed n ₄ is reached.

Otherwise, sharp acceleration or braking pulses are generated by the motor control, which the position of the weights and thus the position of the fixed unbalance A in relation to the Change laundry unbalance B. Then the size and position of the unbalance must be checked again be determined. If the desired result is not achieved despite repeated attempts, the drum can be stopped and the laundry redistributed.

The above-described method for changing the position of the weights can also be used are formed without a laundry imbalance or a determination of the Positions of unbalance A and B were made. Then the drum from the Standstill accelerated immediately to the first spin speed. Starting from any Placement of the unbalances relative to one another makes the position of the fixed unbalance A possibly existing Laundry unbalance B shifted with the method described above until it face each other and the resulting total unbalance C is as low as possible.

Claims (13)

Washer or washer dryer for washing and spinning laundry a drum (2) which can be rotated about a horizontal or inclined axis by a drive motor (4), a balancing device consisting of at least one circular raceway (12; 20) which rotates with the drum (2) and is concentric to its axis of rotation and within which at least two weights (13; 24) are freely movable, Means (14; 22, 23) for carrying the weights (13; 24) in the raceway (12; 20) in a drum speed range, the minimum value of which is lower than the washing speed, Speed control means (6a-d) for driving the drive motor (4) such that the drum (2) is accelerated from a washing speed below the application speed to a spin speed above the application speed when the center of gravity of the weights (13; 24) is within a predetermined range Area. Drum washing machine or washer dryer according to claim 1,
characterized,
that the means for taking the weights (13) consist of a viscous damping means (14) arranged in the track (12), the viscosity and the size of the weights (13) being dimensioned such that they are entrained at the washing speed. Drum washing machine or washer dryer, in particular according to claim 1,
characterized,
that the means for taking away consist of a locking device (22; 23) which reduces the cross section of the raceway (20). Drum washing machine or washer dryer according to claim 3,
characterized,
that the raceway is at least partially hardened or surface-coated to increase hardness. Drum washing machine or washer dryer one or more of claims 1 to 4,
characterized,
that before the drum (2) accelerates from a washing speed below the application speed to a spin speed above the application speed, the drum is stopped or performs slight swiveling movements. Drum washing machine or washer dryer according to one or more of claims 1 to 5,
characterized by a device (6b; 6c) for sensing the position of the weights (13; 24) or a fixed unbalance (A) generated by the weights (13; 24) during a speed which is below the application speed. Drum washing machine or washer dryer according to claim 6,
characterized,
that for sensing the position of the unbalance (A) the frequency component corresponding to the drum speed of a speed signal of the drum (2) or the drive motor (4) and / or a weight, displacement or acceleration signal of the tub (1) is used. Drum washing machine or washer dryer according to claim 6,
characterized,
that for sensing the position of the weights (13; 24) they are made of a material with a high permeability and that at least one stationary magnetic sensor is arranged in the washing machine housing (8) or on the tub (1). Method for washing and spinning laundry in a washing machine or washer-dryer with a drum (2) which can be rotated about a horizontal or inclined axis by a drive motor (4), with a balancing device consisting of a concentrically rotating drum The ring-shaped raceway (12; 20) is arranged on its axis of rotation, within which at least two weights (13; 24) are freely movable, and with means (14; 22, 23) for taking the weights (13) along in the raceway in a drum. Speed range, the minimum value of which is lower than the washing speed,
characterized,
that the drum (2) is accelerated from a washing speed below the application speed to a spin speed above the application speed when the center of gravity of the weights (13; 24) is in a predetermined range. Method according to claim 9,
characterized,
that before the acceleration to a spin speed above the application speed, the drum (2) is stopped during a holding time and that the drum (2) is then first rotated by the microprocessor controller (6) at a washing speed while counting the drum rotations. Method for washing and spinning laundry in a washing machine or washer-dryer with a drum (2) which can be rotated about a horizontal or inclined axis by a drive motor (4), with a fixed unbalance A arranged on the drum, in particular with a balancing device, Consisting of an annular raceway (12; 20) rotating with the drum, concentric to its axis of rotation, within which at least two weights (13; 24) are freely movable, and with means (14; 22, 23) for taking the weights with them (13) in the race in a drum speed range whose minimum value is lower than the washing speed,
characterized,
that the drum (2) is accelerated from a washing speed below the application speed to a spin speed above the application speed when the center of gravity of the weights (13; 24) is in a predetermined range, the range being controlled by a microprocessor controller (6) in Depending on the washing speed and / or the initial acceleration of the drum (2) and / or the type and / or weight of the laundry (3) is determined. Method for balancing the drum (2) of a washing machine with a balancing device, comprising at least one circular raceway (12; 20) that rotates with the drum (2) and is arranged concentrically to its axis of rotation, within the at least two weights (13; 24) are movably arranged, in particular according to one of claims 9 to 11, wherein the method includes accelerating the drum to a speed at which the laundry rests on the drum shell and the weights are carried along, characterized by the following further method steps: Sensing the size and position of the fixed unbalance A produced by the weights, the laundry unbalance B and / or the size of the total unbalance C resulting from these unbalances
Generate positive or negative acceleration pulses for changing the position of the weights if the size of the total unbalance is above a predetermined limit unbalance or if the unbalances A and B are not opposite each other with respect to the drum axis Repeating the sensing of the size and the position of the unbalances A and B or the total unbalance C resulting from these unbalances and the following method steps. Method of balancing the drum according to claim 12,
characterized,
that after a predetermined number of repetitions the spin-up is stopped and the laundry is redistributed.

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