EP1277431A1 - Domestic appliance with an adjustable liquid distributor and the method to control the distributor - Google Patents

Abstract

The device has an adjustable liquid distribution device (8) for detecting the distribution of liquid within the device and at least one detector (20, 21, 30) for detecting a level of the liquid dependent on the liquid distribution device. The detection device contains a liquid level sensor on the suction side of a circulation pump (6). AN Independent claim is also included for the method of detecting the function of an adjustable liquid distribution device.

Description

The invention relates to a household appliance, in particular a Dishwasher, with an adjustable liquid distribution device for adjusting the liquid distribution within the home appliance, as well as a control method the liquid distribution device.

EP 0 237 994 B1 and WO 01/03568 A1 each have one Dishwasher with a switchable distributor valve known. From the dishwasher sump of the dishwasher is sucked in by a circulating pump and rinsing liquid the distributor valve is fed to an upper and lower spray arm. A movable ball is arranged in the distributor valve, which by varying the operation of the circulation pump over time first line to the upper spray arm, a second line to lower spray arm or in an intermediate position both lines releases to both spray arms. If the circulation pump is out of operation, the switching element falls into a defined basic state inside the distribution valve. The switching of the distributor valve enables the selection of the one to be operated Spray arm so that. e.g. if there is little wash load, only one spray arm underneath Water saving is operated or the wash ware from only one Spray arm with a large amount of rinsing liquid is applied.

The object of the invention is to provide a household appliance and to provide for this a procedure in which the safe achievement a switching position of a liquid distribution device is verifiable.

This object is achieved with the features of claims 1 and 11 respectively solved.

According to claim 1 is in a household appliance during operation through an adjustable liquid distribution device the liquid is distributed within the household appliance. For example, in a dishwasher, that of a Circulation pump circulated rinsing liquid through the liquid distribution device distributed on different spray arms. The liquid distribution device can work linearly, i.e. the liquid distribution vary continuously or switch the liquid distribution gradually. For this preferably has the liquid distribution device at least one control element with which the distribution of the Liquid is set within the facility. there it can happen that the control element is not controlled correctly or the desired position has not been reached. Thereby can after a switchover at the liquid distribution device the actual distribution of the liquid deviate from the desired liquid distribution. To capture such a deviation becomes a detection device provided with the actual state of the liquid is detected within the household appliance. By capturing the actual state as a measure of the liquid distribution a comparison with the desired state of the Allows liquid distribution device. Independent of the possible cause of the malfunction of the liquid distribution device becomes the impact of the malfunction detected. The fluid distribution or a change in Fluid distribution affects the fluid flow, on the liquid level, on the pressure of the liquid in different areas or the like.

The liquid distribution device can be hydraulic, for example be switched by the liquid flow, such as. by means of the ball valve known from EP 0 237 994 B1. Or the liquid distribution device is through an adjusting element coupled to a motor drive adjusted, e.g. with a rotary valve, a valve disc or similar. The motor drive is for example a magnetic switch, an electric motor, a pneumatic one or hydraulic device.

Check the condition of the liquid with a liquid level sensor detected, so the individual switching states of the liquid distribution device based on the differences in fluid levels be recorded. Here, e.g. dependent on the switch position different amount of liquid in Circulated liquid lines within the household appliance distributed or the like, so that for each switching position sets a different liquid level.

The liquid level can be advantageously with an analog Pressure sensor, with a float switch, a pressure switch, an ultrasonic level meter or the like. The measurement can be done discretely by using different level positions be detected, or continuously, so that a possible exact level determination can take place. With a pressure sensor the liquid column above the pressure sensor determine.

In a particularly advantageous embodiment, the liquid level sensor arranged on the suction side of a circulation pump. Since there is always liquid at this point, can measure liquid levels regardless of the selected distribution be performed. In addition, too Start of a rinse cycle, a wash cycle or the like Measurement of the amount of liquid filled in the household appliance be performed. This means that only one component is required the amount of liquid in the household appliance and the actual position of the liquid distribution device to capture. This is advantageously done in the bottom area of a container of the household appliance. For example in the dishwasher sump in the dishwashing container of a dishwasher, because the Flushing liquid moved comparatively slowly and an average the liquid level is particularly easy to measure.

In addition to the level measurement or alternatively, the Condition of the liquid with a liquid flow meter detected. The liquid measurement can be done directly by a Lever, which is deflected by the fluid pressure, by a measuring wheel or indirectly through a pressure sensor on the Liquid back pressure reacts to be measured. To do this one or more flow meters in the line system of the household appliance provided, with a known delivery rate one Circulation pump of the household appliance the flow rate of the liquid depends on the individual line sections, which switching state the liquid distribution device occupies. At least one flow sensor is advantageous here Inlet and / or at least one outlet of the liquid distribution device arranged.

The signal detected by the detector about the state the liquid is advantageous via a signal line sent to a control device. In the control device the detection signal is then further evaluated. typically, the control device is the program sequence control of the household appliance. For example, the washing program control one Dishwasher.

The control device is in turn connected to a control line the liquid distribution device and / or a circulation pump connected. Depending on whether the liquid distribution device is converted by a motor drive or e.g. due to the timing of the circulation pump, corresponding Control signals provided by the control device.

According to the method of claim 11, the function is a adjustable liquid distribution device of a household appliance based on the state of the liquid after adjusting the liquid distribution device actually ingested is recorded.

The current state of the liquid is also advantageous compared to a predetermined target value. Depending on the number of Switching states are advantageously several different, predetermined ones Setpoints are provided, each of the current state the liquid should be reached when the liquid distribution device works correctly. Preferably each switching state is compared using its own setpoint, so that a clear assignment can take place.

In a particularly advantageous embodiment, the liquid distribution device via an intermediate position again switched to the selected position if based on a deviation the current state of the liquid from the setpoint it was detected that the desired position was not reached. Is e.g. an adjustment device of the liquid distribution device jammed for a short time or due to contamination not tightly closing in the liquid at an outlet opening, so this state is preferred by interposing of the idle state, and again controlling the desired Position brought about.

The number of repetitions is preferably limited, whereby if the number is exceeded and further malfunction of the Liquid distribution device issued an error message becomes. This will make the user of the household appliance above it informs that maintenance must be carried out. in this connection can be provided that the household appliance despite the malfunction continues to operate.

In a very particularly advantageous embodiment, the Setpoint for a given position of the liquid distribution device not fixed unchangeably, but will adjusted based on other operating parameters of the household appliance. For example, in a dishwasher for one Rinsing program requires more rinsing liquid than for another Rinsing program, the specified setpoint is corresponding to the Adjusted the amount of rinsing liquid. For example, changes the liquid level in the bottom area of a container of the Household appliance, depending on whether more or less total amount of liquid is used. Therefore, it also changes during operation the liquid distribution device in different positions the absolute value of the specified target value or values.

Standardization of the target value or values in one is advantageous specified operating state of the dishwasher carried out. By normalizing the specified setpoint For example, there may be a deviation in the total amount of liquid filled be balanced. This is e.g. a correction in a dishwasher if increased Wash liquid sticks to the wash ware. Can continue with it operational wear and tear, e.g. the circulation pump can be taken into account with little effort.

Exemplary embodiments of the invention are illustrated with the aid of figures explained.

Show it:

Fig. 1 is a schematic representation of a rinsing liquid circuit in a dishwasher and

Fig. 2 different rinsing liquid levels in the dishwasher sump at different positions of a ball switch.

Fig. 1 shows a schematic representation of the rinsing liquid circuit in a dishwasher. In a flushing room 1 of the dishwasher is an upper spray arm 2, a lower spray arm 3 and an upper and lower crockery basket 4 arranged .. The spray arms 2, 3 in the crockery baskets 4 stored items to be washed with washing liquid, the then in the wash cabinet 1 or the wash tank in the dishwasher sump 5 collects. The rinsing liquid is supplied by a circulating pump 6 sucked out of the dishwasher sump 5 and through a connecting line 7 promoted to a changeover valve 8 or ball switch. In the changeover valve 8, the rinsing liquid from the circulation pump 6 optionally through a first line 9 to the upper Spray arm 2, through a second line 10 to the lower spray arm 3, or both to the lower and upper spray arm 2, 3 passed. A bypass line 11 leads from the valve body to the suction side the circulation pump 6.

A flow guide body is located within the valve body of the changeover valve 8 18 arranged by the circulation pump 6 incoming liquid flow streamlined to the first and / or second line 9, 10 deflects. Furthermore is inside of the valve body a ball 14 movably mounted, which in Fig. 1 marked I, II and III switch positions can take. In switch position I the bypass line 11, in switch position II, the first line 9 and in the Position III closed the second line 10. In the position I is the ball 14 by the pressure difference between the flowing into the switching valve 8 rinsing liquid and inlet-side suction held in front of the circulation pump 6. additionally flows around the ball through the flow guide 18 14 prevented in position I.

When the circulation pump 6 is not in operation, the ball 14 falls regardless of their previous position I, II or III in a not shown home position, which due to the oblique course of the guide for the ball 14 within the 'Switch valve 8 slightly below and left to the position II lies (in the top view of Fig. 1). Switching takes place in a similar manner as in EP 0 237 994 B1 or WO 01/03568 A1. By starting the circulation pump 6, the ball 14 first placed in position II, where they are the first line 9 closes. A defined amount of leakage flows into the Line 9. As soon as the circulation pump is switched off briefly, the liquid from the first line 9 pushes the ball 14 in Direction ball position III. At this point the circulation pump 6 started again, the ball 14 is held there and the line 10 closed. The circulation pump 6 at switched off position III of the ball, it moves towards position II or basic position. On the way of the ball from position II to III or from position III to II or the basic position, the ball can be switched on by the Circulation pump must be held in position I. In this case both spray arms 2, 3 are acted upon with rinsing liquid.

The liquid level of the washing liquid in the dishwasher sump 5 depends on whether the circulation pump 6 is in operation and which position the ball 14 occupies. As soon as the fresh water supply was turned off and the circulation pump 6 out of operation is, the rinsing liquid runs from lines 9 and 10 and the spray arms 2, 3 back or out and collects in the Dishwasher sump 5. At this point, there is a maximum Rinse liquid level in the dishwasher sump 5, such as it is marked with the level A in FIG. 2.

If the ball is in position II after a switching operation, so only the lower spray arm 3 is acted upon with rinsing liquid. Here are the second line 10 and the lower one Spray arm 3 filled with rinsing liquid and a certain amount of rinsing liquid, that was sprayed from spray arm 3 is still did not run back into the dishwasher sump. Compared to the Liquid level A causes this additional amount of liquid required a decrease in fluid level A to the level B. Was the ball 14 by means of a switching operation the circulation pump 6 in position III, so the upper spray arm 2 with rinsing liquid, the first line 9 and the spray arm 2 filled with liquid are. A certain amount of liquid is also not yet gets back into the dishwasher sump 5 because e.g. at the Washware and adheres to the walls of the washing compartment and from have to run back there. Due to the larger volume of the first line 9 opposite the second line 10 and the Distribution of the washing liquid on the items to be washed in the upper and lower crockery basket 4 is the liquid level C in this State even lower compared to liquid level B, as shown in Fig. 2.

Finally, the ball 14 was switched to position I, so both the upper and the lower spray arm 2, 3 with Flushing liquid applied. Both spray arms 2, 3 and the lines 9 and 10 are filled with rinsing liquid, and the in Rinsing space 1 distributed amount of rinsing liquid is greatest here. Therefore, the liquid level D is in this switch position even lower. Thus, any position of the ball valve a fluid level can be assigned, summarizing level A is reached in the basic position of the ball 14, in position II the level B, in position III the level C and in position I level D.

To monitor the liquid level is at the bottom of the dishwasher sump 5 a pressure sensor 21 or ultrasound level meter arranged the the middle level of the rinsing liquid detected in the dishwasher sump 5 .. The corresponding signal is from the pressure sensor 21 via a signal line 22 to a control unit 20 transferred to the dishwasher. The control unit 20 compares the signal from the pressure sensor 21 with one Setpoint and causes the circulation pump 6 in the event of a deviation of the actual value from the setpoint for a new activation of the desired Position of the ball 14 in the changeover valve 8. For this becomes a control signal from the control unit 20 via the control line 25 sent to the drive unit 24 of the circulation pump 6.

As described above, for each of the positions I, II, III and the basic position has its own liquid level A, B, C and D, and accordingly a separate setpoint for each Position of the ball 14 in the changeover valve 8. At the beginning of a rinse cycle, the setpoint is advantageously used a standardization is established. This will be for the washing program required fresh water is introduced and circulated for a short time. After switching off the circulation pump 6 'and a short waiting time the setpoint for basic level A is then set, in which a certain amount of washing liquid adheres to the wash ware or was collected in it. Regarding this standardized Basic level A now becomes levels B, C and D as relative setpoints set. Through this standardization e.g. Fluctuations in fresh water supply or differences the washing liquid adhering to the items to be washed is compensated.

In addition, it can be provided that the setpoints, which with the actual values in the different positions are compared, also depend on the selected speed of the circulation pump 6, because the amount of liquid in the lines 9, 10 and Spray arms 2, 3 and the one currently distributed in the wash cabinet 1 Flushing liquid from the liquid pressure and from the pump speed depend.

If there is a deviation between the measured level and a the desired positions I, II, III of the ball 14, an attempt is made to control the circulation pump 6 to reach the position of the ball 14 again. E.g. to Repeating this switching attempt five times the desired one Position not yet reached or the associated fluid level is not recorded, so for the operator at the control console an error message is displayed and the rinsing operation is canceled or continued with the malposition.

Alternatively, if there is a discrepancy between the actual and the Setpoint of the liquid level e.g. tries three times the one you want Switch position by activating the circulation pump 6 to reach. Was not after the third shift attempt a new standardization of the liquid levels is achieved carried out by e.g. the circulation pump 6 turned off and one Standardization of the liquid level A with the circulation pump switched off 6 is carried out. With the new standardized setpoints the desired switching position is then activated again and the setpoint and actual values are compared again. E.g. to three switching attempts again did not reach the position, an error message is also output as above.

In a second embodiment, instead of or in addition to the pressure sensor 21 (or ultrasonic level meter), flow sensors 30, 32 or pressure sensors are provided. Here is the first flow sensor 30 on the first line 9 and the second Flow sensor 32 arranged on the second line 10. The Flow meters 30, 32 have a driver 31, which in the Line 9 or 10 protrudes and through the liquid flow is operated. This is based on the flow of the liquid of the driver 31 detected and it can be determined whether and through which of the lines 9, 10 rinsing liquid flows. In the basic position, i.e. when the circulation pump is switched off 6 none of the flow sensors 30, 32 responds. Is the ball 14 in position II, only the flow sensor 32 detects Signal that is sent to the control unit 20 via a signal line 33 is directed. In position III only the flow sensor detects 30 a signal that is sent via a signal line 34 the control unit 20 is directed. Detect in position I. both the first and the second flow sensors 30, 32 Signal.

In the control unit is obtained by comparing the Signals from the flow sensors 30, 32 and at the desired one Position expected signals a malposition of the Switch valve 8 detected. In the event of a malposition or deviation e.g. a changeover of the changeover valve 8 made by means of the circulation pump 6, as in the above determined deviation based on the measured with the pressure sensor 21 Liquid level is described.

If a pressure sensor is used instead of the flow sensors 30, 31, so can be due to the resulting in the lines 9, 10 Dynamic pressure, a pressure change can be detected, and so likewise, whether the lines 9, 10 flow with flushing liquid become. A malposition of the changeover valve 8 can then accordingly as described for the flow sensors 30, 32, be recorded.

LIST OF REFERENCE NUMBERS

1:

Wash cabinet

2:

upper spray arm

3:

lower spray arm

4:

dish rack

5:

Dishwasher swamp

6:

circulating pump

7:

connecting line

8th:

switching valve

9:

first line

10:

second line

11:

Bypass line

14:

Bullet

18:

flow guide

20:

control unit

21:

pressure sensor

22:

signal line

24:

drive unit

25:

control line

30:

first flow sensor

31:

takeaway

32:

second flow sensor

33:

signal line

34:

signal line

Claims (16)

Household appliance, in particular dishwasher, with an adjustable liquid distribution device for adjusting the liquid distribution within the household appliance,
marked by
at least one detection device (20; 21, 30, 32) for detecting a state (A - D) of the liquid which is dependent on the liquid distribution. Domestic appliance according to claim 1, characterized in that the detection device (20; 21) comprises a liquid level sensor (21). Household appliance according to claim 2, characterized in that the liquid level sensor (21) is arranged on the suction side of a circulation pump (6). Household appliance according to claim 2 or 3, characterized in that the liquid level sensor (21) measures the liquid level (A - D) in the bottom region (5) of a container. Household appliance according to one of the preceding claims, characterized in that the detection device (20; 30, 32) comprises a sensor (30, 32) for the liquid flow, preferably a flow sensor (30, 32) in an inlet (7) and / or at least one outlet (9, 10) of the liquid distribution device (8) is arranged. Household appliance according to one of the preceding claims, characterized by a control device (20) which is connected via a signal line (22, 33, 34) to a sensor (21, 30, 32) of the detection device (20; 21, 30, 32). Household appliance according to claim 6, characterized in that the control device (20; 21, 30, 32) is connected via a control line (25) to the liquid distribution device (8) and / or a circulating pump (6). Household appliance according to one of the preceding claims, characterized in that the adjustable liquid distribution device (8) has at least two outlets and a switching element (14) for releasing or closing the liquid flow through the outlets. Household appliance according to one of the preceding claims, characterized in that the liquid distribution device (8) adjustably supplies the liquid to a first and / or second liquid spray device (2, 3). Method for detecting the function of an adjustable Liquid distribution device (8) of a domestic appliance, the current setting based on the state of the liquid the liquid distribution device (8) is detected , preferably the detected state (A - D) of the Liquid a liquid flow and / or a liquid level is. The method of claim 10, wherein the current state (A - D) the liquid with at least one predetermined Setpoint, which is preferably from a selected position (I - III) of the liquid distribution device (8) depends, is compared. The method of claim 11, wherein in the event of a discrepancy between the setpoint and the current state (A - D) of the Liquid the liquid distribution device (8) again is switched to the selected position (I - III). The method of claim 12, wherein the step of claim 15 is repeated n times, where n is a predetermined one Number is. The method of claim 11, 12 or 13, wherein one An error message is output when the selected position (I - III) is not reached. Method according to one of claims 11 to 14, in which the predetermined setpoint or values from the operating parameters depend on the household appliance and / or on the amount of Liquid in the household appliance and / or from the selected program depend. Method according to one of claims 11 to 15, in which the specified setpoint by standardization in a defined one Condition of the liquid is determined.

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