EP2416694A1

EP2416694A1 - Water-conducting household appliance, particularly a dishwasher

Info

Publication number: EP2416694A1
Application number: EP10709497A
Authority: EP
Inventors: Bernd KRÄNZLE; Stephan Lutz; Michael Rosenbauer; Markus Wecker
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2009-04-06
Filing date: 2010-03-16
Publication date: 2012-02-15
Anticipated expiration: 2030-03-16
Also published as: DE102009002224A1; EP2416694B1; WO2010115685A1; US20120009074A1; US8734136B2; PL2416694T3; DE102009002224B4

Abstract

The invention relates to a water-conducting household appliance, particularly a dishwasher, at least comprising a pump (19), by means of which fluid can be pumped in at least one normal operating mode. According to the invention, the pump (19) can be vented by a venting operating mode which can be carried out before the normal operating mode and during which a gas bubble can be pumped against the pumping direction in effect during the normal operating mode at least partially out of a pump chamber (35) of the pump (19) to a fluid pump inlet (31) of the pump (19).

Description

Water-conducting household appliance, in particular dishwasher

The invention relates to a water-conducting household appliance, in particular a dishwasher, according to the preamble of claim 1.

With water-conducting household appliances, a low-noise operating behavior and the highest possible delivery rate are of great importance. For example. a dishwasher has a drain pump, which is connected to the suction side with a sump. A pump chamber, in which an impeller is running, is in fluid communication with the pump pot in the upper area via a vent opening. In this way, after stopping the pump impeller, the gas collecting above a residual liquid column can escape via the vent opening into the pump pot. The impeller dives deeper into the residual fluid. When switched on again, therefore, the drain pump achieved with a low-noise performance in a short period of time their maximum capacity. A disadvantage of some of the already in the sump filtered rinsing fluid is passed through the vent again back into the sump during pump operation, whereby the flow rate of the drain pump is impaired.

The object of the invention is to provide a water-conducting domestic appliance, in particular a dishwasher with a pump, which has an improved delivery rate.

The solution is based on a water-conducting household appliance, in particular a dishwasher, at least comprising a pump, with which in at least one normal operating mode liquid is conveyed.

According to the invention, the pump can be vented by a vent operating mode which can be carried out before the normal operating mode, during which a gas bubble can be conveyed against the conveying direction during the normal operating mode at least partially from a pump chamber of the pump to a liquid pump inlet of the pump. By the bleed mode of operation may be to one in the prior art usual vent in the pump chamber can be omitted. As a result, no already filtered rinsing liquid can get back into the sump. Compared to the generic venting of pumps, the delivery rate of the pump is improved by the vent operating mode according to the invention. The pump may be operated intermittently during the bleed mode of operation and may temporarily have a lower flow rate than during normal operation of the pump.

For this purpose, the gas bubble is at least partially displaced in a development during the vent mode by a generated by the pump ring flow in the pump. Thus, the gas bubble can be displaced in the direction of the axis of rotation of the impeller, from where it finally reaches the liquid pump inlet.

It is provided in a development that the direction of rotation of the pump during the normal operating mode and the vent operating mode is the same. Thus, it is not necessary to operate in two directions drive to drive the pump and thus no appropriately trained control for driving the drive of the pump.

Furthermore, it is provided in a development that the pump during the Entlüftungsbetriebsmodus with a different speed characteristic than during normal operation mode is operable.

For this purpose, it is provided in a development that the speed characteristic during the Entlüftungsbetriebsmodus has a larger speed fluctuation width than during the normal operating mode. That is, the speed of the pump fluctuates between a lower and upper speed limiting the speed fluctuation width during the normal operation mode and during the purge operation mode. This speed fluctuation width is greater during the bleed operation mode than during the normal operation mode.

Furthermore, it is provided in a development that the speed characteristic during the Enttüftungsbetriebsmodus larger and / or higher speed changes per unit time than during the normal operating mode. That means the speed changes during the bleed mode more than during the normal mode, eg per second or minute as the unit of time.

For this purpose, it is provided in a development that the pump can be operated discontinuously during the venting operating mode. Accordingly, there is no continuous flow. In contrast, the pump is operated continuously in the normal operating mode, so that during operation sets a continuous flow.

Furthermore, it is provided in a development that the pump has a lower delivery rate during the vent operating mode than during the normal operating mode of the pump.

In addition, it is provided in a development that the liquid pump inlet is connected to a pump pot of a pump designed as a drain pump. In doing so, the suds pump serves to dispense liquid, e.g. contaminated rinse liquor from the water-conducting household appliance to promote a home-based sanitation system.

In a further development, it is provided that a pump wheel of the pump performs at least a jerky rotational movement at least temporarily during the venting operating mode. According to a further development, the bleeding mode of operation is effected by a corresponding control of the liquid pump by a control device. In bleeding mode, the gas bubble remaining after a stop of the pump wheel above a residual liquid column can be at least partially displaced to a liquid pump feed or discharge. This can take place in that the impeller is driven to execute at least one jerky rotational movement. This causes the residual liquid column in the pump chamber to move, which displaces the gas bubble. Due to the jerky rotational movement of the impeller, the residual liquid column can displace the gas bubble in the direction of an axis of rotation of the impeller under a short-term structure of a ring flow. The gas bubble can therefore escape at least partially via an inlet or outlet nozzle of the liquid pump. The inlet or outlet connection can preferably be aligned axially or coaxially aligned with the impeller rotation axis. Investigations have shown that when a short-term generation of a ring flow with turbulent flow pattern, a comparatively large amount of gas is displaced from the pump chamber. Against this background, the jerky rotational movement of the impeller can include up to five revolutions. However, it is particularly preferred if the impeller is moved by a rotation angle which is smaller than 360 °, in particular smaller than 240 ° or 120 °. With such small rotational angle changes on the one hand, the energy consumption is minimal. On the other hand, the time period required for carrying out the jerky rotary movement, which is in the order of a fraction of a second, is also minimal.

To activate the venting operation of the liquid pump, the control device can control the liquid pump with a venting signal. The vent signal may preferably be located directly upstream of the actual start signal, so that after the venting, the actual start of operation of the liquid pump begins, in which the pump is continuously raised to the maximum flow rate.

To drive the liquid pump, a DC motor can be used, in particular a brushless DC motor with electronic commutation, d. H. a BLDC motor. The DC motor can be multi-phase, about two- or three-phase, executed. In particular, when using a two- or three-phase DC motor, the jerky rotational movement of the pump impeller can be particularly easily generated with exactly predetermined rotation angles, only one, or in the case of a three-phase DC motor, only two phases are switched.

Thus, the remaining after the venting operation in the pump chamber gas bubble is largely reduced, a sequence of, in particular up to three jerky rotational movements of the pump impeller can be performed. The rotational movements can be repeated in short time intervals, with an interruption time period of the order of about 0.3 s. The implementation of the jerky rotational movement of the pump impeller itself extends over a short period of time on the order of 0.1 s. In such a constellation, therefore, the entire venting process is less than 1.5 s.

In a particular embodiment, the liquid pump can be used as a drain pump in a dishwasher. The drain pump is connected with its pump inlet to a sump of the dishwasher, in which the gas bubble can escape after jerky movement of the pump impeller. The pump inlet can preferably be arranged coaxially with the axis of rotation of the pump impeller.

The jerky rotational movement of the impeller can be done without building up a fluid pressure with which a pressure-side check valve element is opened. In the case of the washer of the dishwasher, the pressure-side check valve element separates the hydraulic circuit of the dishwasher from the sewage network.

Hereinafter, an embodiment of the invention with reference to the accompanying figures will be described.

Show it:

1 shows a schematic block diagram of a dishwasher;

FIG. 2 is an enlarged sectional view of the sump of the dishwasher with associated suds pump; FIG.

3 and 4 are enlarged views of the sectional view shown in FIG. 2 when the pump impeller is stopped and when a jerky movement of the pump impeller is carried out.

In FIG. 1, a dishwasher with a washing container 1 is shown roughly schematically as an exemplary embodiment of a water-conducting domestic appliance, in which dishes that are not shown can be arranged in dish racks 3, 5. Im shown Rinsing containers 1 are arranged by way of example as spraying means two spray arms 7, 9 provided in different spray levels, with which rinse liquid to be rinsed is applied to the items to be cleaned. In Spülbehälterboden a pump pot 11 is provided with associated circulating pump 13, which is fluidly connected via fluid lines 14, 15, 16 with the spray arms 7, 9.

The sump 11 is also connected to a, connected to the water supply network fresh water supply line 17 and a drain line 18 in connection, in which a drain pump 19 is connected to pump out contaminated rinsing liquid from the washing compartment 1. According to FIG. 1, the drain pump 19 is followed by a check valve 27. Downstream of the check valve 27, a siphon section 29 follows in the sewer line with mutually opposite vertical line sections, so that a liquid column of predetermined height in the reverse direction against the check valve 27 builds up a liquid pressure.

In the sump 11, a filter system for cleaning the circulating in the hydraulic circuit rinsing liquid is provided. The filter system has a flat, funnel-shaped fine filter 21, which sits on the top of the pump pot 11, and a centrally located in the pump pot 11 hollow cylindrical, cup-shaped large filter 22.

During a rinse cycle of the dishwasher, the operation of the pumps 13, 19 and other device components, not shown here, is controlled by the control device 23. A rinse may include partial program steps with or without liquid feed, such as pre-rinsing, cleaning, intermediate rinsing, rinsing and drying.

Between two successive partial program steps with liquid use, such as between the pre-rinsing and the cleaning, a rinsing liquid change takes place. In the rinsing liquid change, the no longer required, contaminated rinsing liquid is derived by putting the drain pump 19 from the washing tank 1 into the waste water supply network. In addition, fresh water is introduced via the fresh water supply into the pump pot 11.

FIG. 2 shows, in an enlarged sectional illustration, the sump 11 with associated sump pump 19. Within the pump pot 11 is the hollow cylindrical coarse filter 22 indicated in dashed line. On the bottom side, the sump 11 is connected via an intake 31 with the drain pump 19 in connection. The intake manifold 31 is formed in a pump cover 33 of the drain pump 19, which limits the front side of a pump chamber 35. The drain pump 19 has an impeller 37, which is rotatably mounted in the pump chamber 35. The pump chamber 35 opens into an outlet-side pressure port 39 on a radially outer side lying behind the plane of the drawing. The check valve 27 designed as a check valve can be seen within the pressure port 39, which prevents backflow through the pressure port 39 into the pump chamber 35 during delivery.

The lye pump 19 is driven by way of example with a three-phase brushless DC motor 43 with electronic commutation. The roughly indicated in Figures 2 to 4 DC motor 43 has a rotor permanent magnet 45 which is mounted on a rotor shaft 46 which in turn carries the impeller 37. The rotor stator magnet 45 is surrounded by rotatably arranged stator packs 47 which generate a rotating magnetic field in pump operation with appropriate control by the control device 23, which carries the rotor permanent magnet 45.

In Fig. 3, the drain pump 19 is shown out of service, so that the impeller 37 is stopped. In this state, a residual liquid column h builds up in the pump chamber 35, above which a gas bubble remains. According to FIG. 3, the gas bubble is trapped in the upper apex region of the pump chamber 35 and in the transition to the discharge nozzle 39. In addition, a impeller blade partially protrudes into the gas bubble.

The drain pump 19 is activated during the wash cycle for a liquid change, which takes place after execution of a partial program step, such as the pre-wash, and before the start of the subsequent part program step, such as cleaning.

The trapped in the pump chamber 3 gas bubble increases the time until the drain pump 19 runs at maximum capacity. It is therefore displaced in a vent operating mode, the gas bubble from the pump chamber 35. The bleed mode of operation takes place immediately before the actual operation of the Lye pump 19 instead. For this purpose, the drain pump 19 is controlled before the actual operation start signal S ₆ with a vent signal S _E , which starts the e-vent operating mode. In the bleeding mode, two phases of the three-phase DC motor 43 are energized, whereby the pump 37 rotates jerkily by 270 °. The jerky rotational movement I is illustrated in FIG. 4 with an arrow.

The bleeding mode of operation here has, for example, three consecutive jerky rotational movements I of the impeller 37, which are separated from each other only fractions of a second of about 0.3 s. As a result of each of these jerky rotational movements I, an annular flow running radially around the rotational axis of the pump wheel 37 builds up from the stationary residual liquid column h, as shown in FIG. 4. Due to the structure of this ring flow, the gas bubble is displaced in the direction of the axis of rotation of the impeller 37. Even before a laminar flow pattern is established in the annular flow, the 270 ° rotational movement of the pump impeller 37 abruptly aborted again. As a result, the gas bubble displaced to the axis of rotation as shown in FIG. 4 is largely hurled formally out of the pump chamber 35 through the intake manifold 31 into the pump pot 11.

Only after expiration of the bleeding mode of operation, the DC motor 43 is driven with the operation start signal S ₆ . In contrast to the jerky rotational movement I of the impeller 37 during the venting process, the speed of the impeller 37 is not abruptly raised during the subsequent start of operation, but continuously until reaching the maximum flow rate.

LIST OF REFERENCE NUMBERS

1 bobbin

3, 5 baskets

7.9 spray arms

11 pump pot

13 circulation pump

15, 16 fluid lines

17 fresh water supply

19 drain pump

21 fine filters

22 coarse filter

23 control device

27 check valve

29 Siphon section

31 intake manifold

33 pump covers

35 pump chamber

37 impeller

39 discharge nozzle

43 DC motor

45 rotor permanent magnet

46 rotor shaft

47 Stator packages h Remaining liquid column

I jerky rotation

SE bleed signal

SB start signal

Claims

1. A water-conducting household appliance, in particular a dishwasher, at least comprising a pump (19) with which in at least one normal operating mode liquid is conveyed, characterized in that the pump (19) can be vented by a feasible before the normal operating mode bleeding mode during which a gas bubble against the conveying direction during the normal operating mode at least partially from a pump chamber (35) of the pump (19) to a liquid pump inlet (31) of the pump (19) is conveyed.

2. Water-conducting household appliance according to claim 1, characterized in that during the vent operating mode generated by the pump (19) ring flow in the pump (19) displaces the gas bubble at least partially.

3. Water-conducting household appliance according to claim 1 or 2, characterized in that the direction of rotation of the pump (19) during the normal operating mode and the venting mode is the same.

4. Water-conducting household appliance according to one of the preceding claims, characterized in that the pump (19) during the

Bleed operating mode with a different speed characteristic than during normal operation mode is operable.

5. Water-conducting household appliance according to claim 4, characterized in that the speed characteristic during the bleeding mode of operation a larger

Speed fluctuation width than during the normal operation mode.

6. Water-conducting household appliance according to claim 4 or 5, characterized in that the speed characteristic during the Entlüftungsbetriebsmodus larger and / or higher speed changes per

Time unit than during the normal operation mode.

7. Water-conducting household appliance according to claim 4, 5 or 6, characterized in that the pump (19) is discontinuously operable during the bleeding mode of operation.

8. Water-conducting domestic appliance according to one of the preceding claims 1 to 7, characterized in that the pump (19) during the

Bleed operating mode has a lower flow rate than during the normal operation mode of the pump (19).

9. Water-conducting domestic appliance according to one of the preceding claims 1 to 8, characterized in that the liquid pump inlet (31) with a

Pump pot (1 1) is designed as a drain pump designed as a pump (19).

10. A water-conducting domestic appliance according to one of the preceding claims 1 to 9, characterized in that a pump wheel (37) of the pump (19) at least temporarily during the vent operating mode at least one jerky

Rotary movement (I) executes.

11. Water-conducting domestic appliance according to claim 10, characterized in that the impeller (37) during the jerky rotary movement (I) rotates about a rotation angle which is smaller than 360 °, in particular smaller than 240 ° or 120 °.

12. A water-conducting household appliance according to any one of claims 10 or 1 1, characterized in that during the vent operating mode, the impeller (37) a sequence of, in particular from three to five, jerky rotational movements (I) executed.

13. Water-conducting domestic appliance according to one of the preceding claims 10 to 12, characterized in that the jerky rotary movement (I) of the pump impeller (37) is repeatable in spaced-apart time intervals.

14. Water-conducting household appliance according to one of the preceding claims claims 1 to 13, characterized in that during the Venting mode a pressure-side check valve element (27) is closed.

15. Water-conducting household appliance according to one of the preceding claims 1 to 14, characterized in that for driving the pump (19), a DC motor (43), in particular a brushless DC motor with electronic commutation, is provided.

16. Water-conducting domestic appliance according to claim 15, characterized in that when using a two- or three-phase DC motor (43) for generating the jerky rotary movement (I) of the pump impeller (37) connected only two current-carrying in the case of a three-phase DC motor two phases become.

17. Water-conducting household appliance according to one of the preceding claims 10 to 16, characterized in that the jerky rotational movements (I) of the

Pump impeller (37) over a predetermined period of time, in particular over a period of time substantially from 0.1 s to 0.5 s, preferably from 0.2 s to 0.4 s, are spaced apart in time.

18. Water-conducting household appliance according to one of the preceding claims 10 to 17, characterized in that the jerky movement (I) of the pump impeller (37) over a period of time substantially from 0.05 s to 0.5 s, preferably from 0.1 s to 0.2 s.

19. A method for operating a water-conducting household appliance, in particular a dishwasher, during which at least temporarily with a pump (19) of the water-conducting household appliance liquid is promoted, characterized in that before starting the pump (19) this is vented by operation in a vent operating mode during which a gas bubble at least partially against the conveying direction during the

Normal mode of operation from a pump chamber (35) of the pump (19) to a liquid pump inlet (31) of the pump (19) is conveyed.

20. The method according to claim 19, characterized in that during the venting operating mode, the gas bubble is at least partially displaced by one of the pump (19) generated ring flow in the pump (19).

21. The method according to claim 19 or 20, characterized in that pump (19) is operated during the normal operating mode and the bleeding mode with the same direction of rotation.

22. The method according to any one of the preceding claims 19 to 21, characterized in that the pump (19) is operated during the bleeding mode with a different rotational speed characteristic than during the normal operating mode.

23. The method according to claim 22, characterized in that the

Speed characteristic during the bleeding mode has a larger speed fluctuation width than during the normal operation mode.

24. The method of claim 22 or 23, characterized in that the speed characteristic during the Entlüftungsbetriebsmodus larger and / or higher speed changes per unit time than during the normal operating mode.

25. The method according to any one of the preceding claims 19 to 24, characterized in that the pump (19) is operated discontinuously during the bleeding mode of operation.

26. The method according to any one of the preceding claims 19 to 25, characterized in that the pump (19) during the bleeding mode promotes a smaller amount than during the normal operation mode of the pump (19).

27. The method according to any one of the preceding claims 19 to 26, characterized in that the pump (19) is used as a drain pump whose liquid pump inlet (31) is connected to a pump pot (11).

28. The method according to any one of the preceding claims 19 to 27, characterized in that an impeller (37) of the pump (19) at least temporarily during the venting mode at least one jerky rotational movement (I) performs.

29. The method according to claim 28, characterized in that the impeller (37) during the jerky rotary movement (I) rotates by a rotation angle which is smaller than 360 °, in particular smaller than 240 ° or 120 °.

30. The method according to any one of claims 28 or 29, characterized in that during the vent operating mode, the impeller (37) a sequence of, in particular from three to five, jerky rotational movements (I) executed.

31. The method according to any one of the preceding claims 28 to 30, characterized in that the jerky rotary movement (I) of the pump impeller (37) are repeated at spaced-apart time intervals.

32. The method according to at least one of claims 19 to 31, characterized in that a pressure-side check valve element (27) is kept closed during the vent operating mode.

33. The method according to at least one of claims 19 to 32, characterized in that for driving the pump (19), a DC motor (43), in particular a brushless DC motor with electronic commutation, is used.

34. The method according to claim 33, characterized in that when using a two- or three-phase DC motor (43) for generating the jerky rotary motion (I) of the pump impeller (37) only one or two phases are energized in the case of a three-phase DC motor ,

35. The method according to any one of the preceding claims 28 to 34, characterized in that the jerky rotational movements (I) of the pump impeller (37) over a predetermined period of time, in particular over a period of time in

Substantially from 0.1 s to 0.5 s, preferably from 0.2 s to 0.4 s, are carried out spaced apart from each other.

36. The method according to any one of the preceding claims 28 to 35, characterized in that the jerky movement (I) of the pump impeller (37) over a period of time substantially from 0.05 s to 0.5 s, preferably of 0.1 s to 0.2 s.