EP1458277A1

EP1458277A1 - Dishwasher with a movement reversal device

Info

Publication number: EP1458277A1
Application number: EP02805289A
Authority: EP
Inventors: Michael Rosenbauer; Roland Ertle; Claus KÖTHER
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2001-12-21
Filing date: 2002-11-25
Publication date: 2004-09-22
Anticipated expiration: 2022-11-25
Also published as: JP2005512660A; WO2003053211A1; CN1286425C; US7047986B2; DE50213909D1; AU2002366723A1; US20040226586A1; EP1458277B2; DE10163184A1; DE10163184B4; CN1606421A; DE20122635U1; ATE444700T1; KR20040068598A; EP1458277B1; ES2332404T3; JP4191046B2

Abstract

The control for a dish washer (1) with a washing container (2) and at least two sprays supplied with washing fluid via a pump (7). The control has two outlets for fed the fluid to the sprays which are selectively opened and closed. The control simultaneously controls the operation of the pump and the characteristics of the hydraulic feed. The control can alter the speed of the pump. The valve for controlling the flow can have openings of different cross sections.

Description

DISHWASHER WITH A RETURNING DEVICE

The invention relates to a reversing device, in particular for a dishwasher with a washing container with a hydraulic arrangement with at least two spray devices which act on the items to be cleaned which are arranged in the washing container by means of a liquid conveyed by a circulating pump, the conveyed liquid flowing through a reversing device, and wherein the reversing device has at least two outputs for supplying the liquid to different spray devices, which can be opened or closed by means of an actuating element such that either one of the outputs or a number of outputs or all outputs alternately in succession and / or continuously are open or closed.

From DE-198 57 103-A1 a reversing device of the type mentioned is known, in which the control element is a rotary valve arranged in a continuous-flow heater, which in the direction of circulation alternately has a closed area after an open area, between which there is an empty space , The aforementioned open area is a circular opening.

The rotary slide valve from DE-198 57 103-A1 can be controlled, for example, using an actuator device known from DE-10065571.8 (DE-100 65 571-A1), which includes a motor-driven cam disk that is firmly connected to the rotary slide valve.

From DE-119 07 158-A1 it is known that the speed of the circulation pump can be regulated, whereby DE-199 07 188-A1 proposes, in order to avoid increased noise when changing the spraying devices, the speed of the circulation pump when changing to reduce the spraying devices and, in the already mentioned DE-198 57 103-A1 and also in DE-199 07 157-A1, the speed of the circulation pump is higher when operating a lower spraying device than when operating a upper spraying device to ensure full use of the filled amount of liquid.

With the electronic control of the speed of the circulation pump, only one aspect of the influence on the program sequence, e.g. in a dishwasher, namely a change in the pump characteristic and thus the pressure on the items to be cleaned, e.g. Wash items, and the amount of liquid with which the items to be cleaned, e.g. Items to be washed are loaded.

The object of the invention is to provide a reversing device in a simple manner with which the possibilities of influencing the course of the cleaning program are improved and thus optimally achieve a cleaning effect in accordance with the degree of soiling of the items to be cleaned.

This object is achieved in that the characteristic of the hydraulic arrangement and the characteristic of the circulation pump are changed simultaneously or alternately.

A combination of the influencing of the characteristics on the one hand of the hydraulic arrangement and on the other hand of the circulation pump results in a much greater variability in the program control, e.g. a dishwasher, and thus much greater possible variations in the loading of the items to be cleaned, with which a reversing device was created in a simple manner with which the possibilities of influencing the course of the cleaning program are improved and thus a cleaning effect in accordance with the degree of soiling of the items to be cleaned optimally achieved.

According to a preferred feature of the invention, the characteristic of the hydraulic arrangement is changed by changing the flow of the liquid through the reversing device and the characteristic of the circulating pump by regulating the rotational speed of the circulating pump, with which the combination according to the invention of influencing the characteristic on the one hand of the hydraulic arrangement and on the other hand the circulation pump has succeeded in a simple way. According to a preferred embodiment of the invention, the adjusting element of the hydraulic arrangement has at least one opening with different cross sections compared to at least one further opening. Through at least one smaller opening, it is possible to convey a smaller amount of liquid to a desired spray device, thus creating the simplest possible way of influencing the characteristics of the hydraulic arrangement.

The at least one opening with different cross sections advantageously has a substantially smaller cross section than the at least one further opening, which further simplifies the possibility of influencing the characteristics of the hydraulic arrangement.

In a particularly advantageous manner, the opening with the substantially smaller cross-section than the at least one further opening for supplying the liquid to an upper spraying device is used so that it can be operated with the amount of liquid available for circulation without running dry. Due to the opening associated with the supply of the liquid to an upper spray device with the substantially smaller cross-section compared to the at least one further opening, the amount of liquid - the so-called dead water amount - due to the longer supply of the liquid to the upper spray device is reduced ,

The actuating element is preferably a disk which has at least one opening with the substantially smaller cross section than the at least one further opening. The design of the control element as a disk is the simplest way of implementing the hydraulic arrangement of the reversing device according to the invention.

The at least one larger opening expediently serves essentially to supply the liquid to a lower spray device, but alternatively it can also serve to supply the liquid to the upper spray device. The opening associated with the supply of the liquid to a lower spray device with the substantially larger cross-section compared to the at least one smaller opening makes it possible in a simple manner to deliver significantly larger amounts of cleaning liquid. With the use of at least one large opening alternatively also for the supply line to the upper spray device, the possibility of delivering substantially larger amounts of cleaning fluid to the upper spray device is also created in a simple manner.

For the application described above, in which all of the outputs of the reversing device according to the invention are alternately opened one after the other and / or continuously, two larger openings on the disc opposite one another are preferably used for simultaneously supplying the liquid to a lower and an upper spray device. The variability in the washing program control is increased by the use of differently large quantities of liquid for the different operations of the spray device - only upper spray device - only lower spray device - both spray devices.

Expediently, closed areas of the actuating element, which lie in the closed positions in a sealing manner at the corresponding exits, each have a circumferential sealing edge which protrudes in the direction of the exits. According to a further preferred embodiment of the invention, the smaller opening is also surrounded by a sealing edge which rises in the direction of the exits. This measure ensures a complete sealing system at the corresponding outputs in a simple manner.

Alternatively, the speed of the circulating pump is reduced or increased in predetermined sub-program sections of the washing program sequence or over the entire washing program sequence, whereby the number of program types can be increased further and a particularly good adaptation of the program course to the types of contamination of the objects to be cleaned, e.g. of the dishes in a dishwasher.

With the invention, a reversing device was created in a simple manner, with which the possibilities of influencing the course of the cleaning program are improved and thus a cleaning effect is optimally achieved in accordance with the degree of soiling of the items to be cleaned. The invention is explained below with reference to the embodiments shown in the drawing. Show it:

1 shows a household dishwasher in a schematic illustration, FIG. 2 shows a sectional illustration of the side view of a continuous-flow heater with a reversing device according to the invention, FIG. 3 shows a sectional illustration of the top view of the continuous-flow heater with a preferred embodiment of the reversing device according to the invention in accordance with the section lines III-IM in FIG. 2,

4 shows possible positions of the actuating element of the preferred embodiment of the reversing device according to the invention, FIG. 5 shows possible positions of the actuating element of the further embodiment of the reversing device according to the invention and FIG. 6 shows a pressure-delivery volume diagram with possible pump and system characteristics.

In the exemplary embodiments shown, the reversing device according to the invention is explained in the application for a household dishwasher 1. The household dishwasher 1 (not explained in more detail) has a washing container 2, into which items to be cleaned, not shown, for example soiled dishes and cutlery, are usually filled into dish racks 3, 4. A hydraulic arrangement is provided in the household dishwasher 1, with at least two spray devices, in the exemplary embodiments shown two spray devices 5, 6 being arranged in the washing container 2, which act on the items to be cleaned in the washing container 2 with liquid. This liquid, usually called the washing liquor, is conveyed to the spraying devices 5, 6 by means of a circulation pump 7 in liquid feed lines 8, 9. The liquid conveyed in household dishwashers 1 is usually heated at least in a sub-program section of a washing program, for which purpose the household dishwasher 1 has a continuous-flow heater 10 in the exemplary embodiments shown. The liquid conveyed in the domestic dishwasher 1 is passed from the circulating pump 7 to an inlet connection 11 of the instantaneous water heater 10 and through the instantaneous water heater 10. The instantaneous water heater 10 has at least two outlet ports, namely a number of outlet ports corresponding to the number of spray devices or groups of spray devices operated simultaneously, in the exemplary embodiments shown two outlet ports 12, 13. From the outlet connections 12, 13 of the continuous-flow heater 10, the liquid is fed via the already mentioned liquid feed lines 8, 9 to the respective different spray devices 5, 6. The heating rods required for heating the liquid in the water heater 10 are designated by 16.

The conveyed liquid flows through a reversing device 20 which, in the exemplary embodiments shown, is arranged in the flow heater 10, for which purpose the conveyed liquid is passed from the circulating pump 7 to an inlet connection 11 of the through-flow heater 10, which is therefore also the inlet connection of the reversing device 20. The reversing device 20 has at least two outputs - in the exemplary embodiment shown, the two outlet ports 12, 13 of the continuous-flow heater 10 - for supplying the liquid to different spray devices 5, 6, respectively. These outlet connections 12, 13 can be opened or essentially closed by means of an actuating element 21, 21 'of the reversing device 20 arranged in the flow heater 10 in the flow direction in front of the outlet connections 12, 13 in the exemplary embodiments shown, such that either one of the outlet connections is in each case 12, 13 or a number of outlet ports 12, 13 or all outlet ports 12, 13 are alternately opened one after the other and / or continuously or are essentially closed. For this purpose, the adjusting element 21, 21 'of the reversing device 20, which is designed as a disk in the exemplary embodiments shown, is arranged in the flow direction in front of each outlet port 12, 13 of the outlets 14, 15 of the instantaneous water heater 10. 3 and 4, one of the outputs 14, 15 of the instantaneous water heater 10 can be closed, and the control element 21 'in the further exemplary embodiment shown in FIG. 5 shows the two outputs 14, 15 either alternately in succession and / or be constantly open or essentially closed.

According to the invention, the characteristic of the hydraulic arrangement and the characteristic of the circulating pump 7 are changed simultaneously or alternately, the characteristic of the hydraulic arrangement being changed by changing the flow of the liquid through the reversing device 20 and the characteristics of the circulating pump 7 are changed by regulating the speed of the circulating pump 7.

The change according to the invention in the characteristic of the hydraulic arrangement is now explained below:

For the change according to the invention in the characteristic of the hydraulic arrangement, the adjusting element 21, 2V has at least one opening 22 with a cross section that is different from the cross section of at least one further opening 23. This at least one opening 22 with a different cross section has a substantially smaller cross section than the cross section of the at least one further opening 23. Through at least one smaller opening 22, a possibility is created to convey a smaller amount of liquid to a desired spray device 5, 6 and with an at least larger opening 23, 24, a possibility is created to supply a larger amount of liquid to a desired spray device 5, 6 promote, with which the simplest possible way to influence the characteristics of the hydraulic arrangement was created.

In the exemplary embodiments shown, the opening 22 with the substantially smaller cross-section - hereinafter referred to as the smaller opening 22 - compared to the at least one further opening 23 - hereinafter referred to as the larger opening 23 - is used to supply the liquid to an upper spray device 5. Through the supply line the opening 22 associated with the liquid to an upper spray device 5 and having a substantially smaller cross-section than the at least one further opening 23, the amount of liquid - the so-called dead water amount - which is in the longer supply line of the liquid to the upper spray device 5 is reduced.

In the exemplary embodiments shown, the openings 22, 23 are arranged at right angles to one another on a circle with the same radius, indicated by dash-dotted lines in FIGS. 3, 4 and 5. The arrangement of the openings on the same radius at right angles to one another creates a very simple possibility of controlling the reversing device. In the exemplary embodiments shown, the at least one larger opening 23 thus serves for supplying the liquid to a lower spray device 6, although this can also be used as an alternative to special program sequences Supply of the liquid to the upper spray device 5 can serve. With the use of the at least one large opening 23 alternatively also for the supply line to the upper spray device 5, the possibility of delivering substantially larger amounts of cleaning fluid to the upper spray device 5 is created in a simple manner.

In the further exemplary embodiment shown in FIG. 5, two larger openings 23, 24 located opposite one another on the actuating element 21 '- the disk - serve for the simultaneous supply of the liquid to the lower spray device 6 and the upper spray device 5.

The closed areas of the actuating element 21, 21 '- the disc - which bear in the closed positions on the corresponding exits 14, 15 in a sealing manner are designated by 25 and each have a circumferential sealing edge 26 which protrudes in the direction of the exits 14, 15 , The smaller opening 22 is also surrounded by such a sealing edge 26 (see FIG. 3). With this measure, a complete sealing system at the corresponding outputs 14, 15 is ensured in a simple manner.

The drive unit 30 is a motor 31, e.g. an electric motor, with a gear 32 shown only schematically in Figure 2, e.g. a gear transmission. The control element 21 is connected to the transmission 32 by means of a shaft 33 which is guided in the housing of the water heater 10. The motor 30 and the gear 32 are protected by a cover 18 seated on a raised edge 17 of the instantaneous water heater 10. The cover 18 also has bearing points for the gear 32, of which only a raised journal 19 is shown as a bearing for the shaft 33.

The function of the reversing device 20 according to the invention in the two exemplary embodiments shown is explained below:

The description of the function of the preferred embodiment of the reversing device 20 according to the invention with the actuating element 21 now follows first. With the actuating element 21 of the preferred embodiment of the reversing device 20 according to the invention according to FIGS. 3 and 4, either one of the outputs 14, 15 is alternately opened one after the other and / or continuously or kept essentially closed.

If an alternate loading of the spray devices 5, 6 with the supply of a reduced amount of liquid to the upper spray device 5 is desired, the connection of the motor 31 of the drive device 30 to the supply voltage is initiated by a program control unit of the household dishwasher 1, which is not explained in detail, and the control element 21 4 begins to rotate clockwise, as indicated by an arrow in FIG. As a result, one of the closed areas 25 of the actuating element 21 is rotated until it lies sealingly on the outlet 15 and the smaller opening 22 lies above the outlet 14. This corresponds to the position of the actuating element 21 in FIG. 4b. In this case, the supply of the liquid flowing through the continuous-flow heater 10 to the lower spray device 6 is interrupted and the supply to the upper spray device 5 is opened due to the smaller opening 22 with less liquid passage. The reversing device 20 remains in this position for an exposure time provided in the program sequence, in the exemplary embodiment shown about one minute. For example, the actuator device described in DE-10065571.8 (DE-10065 571-A1), the rotational position of the actuating element 21 is ascertained and the motor 31 is switched off via the program control device for a predetermined duration, so that the respective rotational position of the actuating element 21 is this duration is held. When the spray devices 5, 6 are loaded alternately, the motor 31 then continues to rotate, so that after the actuating element 21 has been rotated by 90 ° in the exemplary embodiment, one of the closed areas 25 lies sealingly on the outlet 14 and the larger opening 23 lies above the outlet 15. This corresponds to the position of the actuating element 21 in FIG. 4c. The supply to the upper spray device 5 is thus interrupted and the supply to the lower spray device 6 is opened with a larger liquid passage. The reversing device 20 now remains in this position again for an exposure time provided in the program sequence, in the exemplary embodiment shown about one minute. When the motor 31 continues to rotate until it reaches the position shown in FIG. 4b - in the exemplary embodiment shown above 270 ° - however, due to the rapid rotation of the actuating element 21, there is only a very short one Opening the outlet 15 through the smaller opening 22 and then opening the outlet 14 through the larger opening 23 (see FIG. 4d and then FIG. 4a) until then again one of the closed areas 25 for contacting the outlet 15 and the smaller bore 22 is on exit 14 and the process continues as described. As described at the beginning, an alternate loading of the spray devices 5, 6 is used in particular to save water, the smaller opening 22 of the actuating element 21 of the reversing device 20 according to the invention for sucking in air with an unpleasant and undesirable noise development of the circulation pump 7 due to the lower liquid passage to the upper spray device 4, so that the suction space of the circulation pump 7 is not emptied.

If, however, alternate loading of the spray devices 5, 6 with a non-throttled liquid supply to the upper spray device 5 is desired, then the actuating element 21 is rotated until one of the closed areas 25 of the actuating element 21 lies sealingly on the outlet 15 and the larger opening 23 is located above exit 14. This corresponds to the position of the actuating element 21 in FIG. 4a. In this case, the supply of the liquid flowing through the continuous-flow heater 10 to the lower spray device 6 is interrupted and the supply to the upper spray device 5 is opened due to the larger opening 23 with a non-reduced liquid passage. The reversing device 20 remains in this position for an exposure time provided in the program sequence, in the exemplary embodiment shown about one minute. When the spray devices 5, 6 are alternately charged, the motor 31 then continues to turn, but now, due to the rapid rotation of the actuating element 21, the outlet 14 is opened further through the smaller opening 22 (see FIG. 4b). , After the actuating element 21 has been rotated by 180 ° in the exemplary embodiment, one of the closed regions 25 lies sealingly on the outlet 14 and the larger opening 23 above the outlet 15. This corresponds to the position of the actuating element 21 in FIG. 4c. The supply to the upper spray device 5 is thus interrupted and the supply to the lower spray device 6 is opened with a larger liquid passage. The reversing device 20 now remains in this position again for an exposure time provided in the program sequence, in the exemplary embodiment shown about one minute. When the motor 31 continues to rotate continuously to the position according to FIG. 4a - in the exemplary embodiment shown above 180 ° again - until then one of the closed areas 25 for contacting the exit 15 and the larger hole 23 is located on the exit 14 and the process continues as described above.

If, however, a constant opening of only the liquid supply line 8 to the upper spray device 5 with a not reduced amount of liquid is desired - a so-called full upper basket rinsing - the sensor system described above is used to operate the motor 31 only until the larger opening 23 of the control element 21 has reached the outlet 14 for the outlet nozzle 12 to the liquid feed line 8 to the upper spray device 5, see FIG. 4a, and then to maintain this position through the complete washing program, since the motor 31 is no longer operated.

If a constant opening of only the liquid supply line 8 to the upper spray device 5, but with a reduced amount of liquid - a so-called throttled upper basket rinsing - is desired, the sensor system described above is used to operate the motor 31 only until the larger opening 23 of the Control element 21 has only partially opened the outlet 14 for the outlet nozzle 12 to the liquid feed line 8 to the upper spray device 5, see FIG. 4d, and then to maintain this position through the complete washing program, since the motor 31 is no longer operated.

If, however, a constant opening of only the liquid supply line 8 to the upper spray device 5, but with the amount of liquid reduced during alternate operation - a so-called heavily throttled upper basket rinse - is desired, the sensor system described above is used to operate the motor 31 only as long as until the smaller opening 22 of the actuating element 21 has opened the outlet 14 for the outlet nozzle 12 to the liquid feed line 8 to the upper spray device 5, see FIG. 4b, and then to maintain this position through the complete washing program, since the motor 31 is no longer operated ,

It is of course also conceivable, as an alternative, to carry out a permanent opening of only the liquid feed line 9 to the lower spray device 6. For this purpose, the motor 31 would only be operated with the sensor system described above until the larger opening 23 of the actuating element 21 passed the outlet 15 for the outlet nozzle 13 to the liquid supply. has reached line 9 to the lower spray device 6, see FIG. 4c, and then, since the motor 31 would no longer be operated, this position would be retained over the complete washing program.

Simultaneous operation of both spray devices 5, 6 without changing between them by simultaneously supplying the liquid - the so-called two-basket rinsing - is not provided in this preferred embodiment of the reversing device 20 according to the invention.

The function of the further embodiment of the reversing device 20 according to the invention with the adjusting element 21 'now follows.

5, either one of the outputs 14, 15 or both outputs 14, 15 are alternately opened one after the other and / or continuously or kept essentially closed.

If an alternate loading of the spray devices 5, 6 is desired, the connection of the motor 31 of the drive device 30 to the supply voltage is initiated by a program control device of the household dishwasher 1, which is not explained in detail, and the control element 21 'begins, as with an arrow in Figure 5 indicated to rotate clockwise. As a result, one of the closed regions 25 of the actuating element 21 ′ is rotated until it lies sealingly on the outlet 15 and the smaller opening 22 lies above the outlet 14. This corresponds to the position of the actuating element 21 in FIG. 5a. In this case, the supply of the liquid flowing through the instantaneous water heater 10 to the lower spray device 6 is interrupted and the supply to the upper spray device 5 is opened. In the exemplary embodiment shown, the reversing device 20 remains in this position for about one minute, the rotational position of the actuating element 21 being determined by means of a sensor system (not described in greater detail) and the motor 31 being switched off via the program control device for a predetermined duration, so that the respective rotational position of the actuating element 21 'is held over this period. When the motor 31 continues to rotate continuously to the position according to FIG. 5 c - in the exemplary embodiment shown over 180 ° - in which one of the closed areas 25 seals on the outlet 14 rests and the smaller opening 22 lies above the outlet 15, both outlets 14, 15 now open through the larger openings 23, 24 (see FIG. 5d), but only very briefly due to the rapid rotation of the adjusting element 21 '. , In the position of the adjusting element 21 'according to FIG. 5c, the feed to the upper spray device 5 is interrupted and the feed to the lower spray device 6 is opened. In the exemplary embodiment shown, the reversing device 20 now remains in this position for about one minute. When the motor 31 continues to rotate to the position according to FIG. 5a - in the exemplary embodiment shown over 180 ° - in which one of the closed areas 25 lies sealingly on the outlet 15 and the smaller opening 22 lies above the outlet 14, it now occurs again, but only very briefly due to the rapid rotation of the actuating element 21, for opening both outlets 14, 15 through the larger openings 23, 24 (see FIG. 5d). In the position of the adjusting element 21 'according to FIG. 5a, the feed to the lower spray device 6 is interrupted and the feed to the upper spray device 5 is opened. In the exemplary embodiment shown, the reversing device 20 now remains in this position for about one minute, then the process is continued as described.

However, if a constant opening of only the liquid supply line 8 to the upper spray device 5 is desired - a so-called throttled upper basket rinsing - the sensor system described above is used to operate the motor 31 only until the smaller opening 22 of the control element 21 'has the exit 14 for the outlet nozzle 12 to the liquid supply line 8 to the upper spray device 5, see FIG. 5a, and then to maintain this position through the complete washing program, since the motor 31 is no longer operated.

If a constant opening of only the liquid supply line 8 to the upper spray device 5, but with a further reduced amount of liquid - a so-called strongly throttled upper basket rinsing - is desired, the sensor system described above is used to operate the motor 31 only until the smaller one Opening 22 of the control element 21 'has only partially opened the outlet 14 for the outlet connection 12 to the liquid feed line 8 to the upper spray device 5, see FIG. 5d, and then to maintain this position through the complete washing program, since the motor 31 is no longer operating is operated. A so-called full upper basket rinsing is not provided in this further embodiment.

If a permanent opening of only the liquid feed line 9 to the lower spray device 6 were now desired, the sensor system described above would only be used to operate the motor 31 until the smaller opening 22 of the actuating element 21 'to the outlet 15 for the outlet nozzle 13 to the liquid supply line 9 to the lower spray device 6, see FIG. 5c, and then to maintain this position through the complete washing program, since the motor 31 is no longer operated.

If, in the further embodiment of the reversing device 20 according to the invention, the uninterrupted operation of both spray devices 5, 6 is desired, the position of the openings 23 and 24 on the adjusting element 21 'to both outputs 14, 15 can be determined again by means of the sensor system described above (see FIG. 5b ) and maintain this position throughout the entire washing program, since the motor 31 is no longer operated. The filling quantity with rinsing liquid is increased accordingly.

The change according to the invention in the characteristics of the circulation pump 7 is now explained below:

According to the invention, the characteristic of the circulation pump 7 is changed by regulating the speed of the circulation pump 7. Alternatively, the speed of the circulation pump 7 is reduced or increased in predetermined sub-program sections of the washing program sequence or over the entire washing program sequence, whereby the number of program settings can be increased further and a particularly good adaptation of the program sequence to the types of contamination of the objects to be cleaned, e.g. of the dishes in a dishwasher.

FIG. 6 shows a pressure-delivery volume diagram with possible pump and system characteristics, in which the pressure p is scaled on the Y-axis and the delivery volume Q on the X-axis. The reduction in the speed of the circulation pump 7 causes a drop in the pressure generated by the circulation pump and thus also in the amount of liquid delivered. Conversely, the increase in the speed of the circulation pump 7 causes an increase in the pressure generated by the circulation pump and thus also in the amount of liquid delivered. Basically, as shown in Figure 6, the pump characteristic curve - see pump characteristic curve PB - is shifted upwards in parallel when the speed increases - see pump curve PA - and downwards in parallel when the speed decreases - see pump characteristic curve PC. As already explained at the beginning of the prior art, for example in order to avoid increased noise when changing the spraying devices, the speed is reduced or, for example, the speed of the circulation pump is increased when the lower spraying device is operated than when the upper spraying device is operated in order to make full use of the spraying device ensure the amount of liquid filled.

The effect of the combination according to the invention of the two change measures described above will now be explained.

According to the invention, the characteristic of the hydraulic arrangement and the characteristic of the circulation pump 7 are changed simultaneously or alternately.

In addition to the examples for the position of the pump characteristics PA, PB, PC, FIG. 6 also shows the system characteristics AA, AB, AC, AD for the above-mentioned different settings of the reversing device 20 and thus the changed characteristics of the hydraulic arrangement. The system characteristic curve AA is the system characteristic curve for the position of the actuating element 21 in FIG. 4b and that of the actuating element 21 'in FIG. 5a, in which the supply of the liquid flowing through the water heater 10 to the lower spray device 6 is interrupted and the supply to the upper spray device 5 is opened due to the smaller opening 22 with less liquid passage. The system characteristic curve AB is the system characteristic curve for the position of the actuating element 21 in FIG. 4c, in which the supply to the upper spray device 5 is interrupted and the supply to the lower spray device 6 is opened with a larger liquid passage. The system characteristic curve AC is the system characteristic curve for the position of the actuating element 21 in FIG. 4a, in which the supply of the liquid flowing through the instantaneous water heater 10 to the lower spray device 6 is interrupted and the supply to the upper spray device 5 is opened due to the larger opening 23 with not reduced liquid passage. The system characteristic curve AD is the system characteristic curve for the position of the actuating element 21 'in FIG. 5b, in which the uninterrupted operation of both spray devices 5, 6 is set and both outlets 14, 15 are open with a not reduced liquid passage.

As can be seen from Figure 6 at the twelve crossing points of the pump characteristics PA, PB, PC with the system characteristics AA, AB, AC, AD, which serve only as examples, there are various working points with different pressure and pressure for the basically infinite combination possibilities Liquid flow rate values, which enables almost unlimited variation in the loading of the goods to be cleaned. In the case of program sequences which can be set either by the user according to his assessment of the degree of soiling of the goods to be cleaned or by means of a suitable sensor system of the household dishwasher 1 and which then contain the corresponding operating points, the program sequences become much more precise in relation to the degree of contamination of the goods to be cleaned customized.

In FIG. 6, the use of a pump type at different speeds is shown using a few examples. The possible variations are of course further increased when using different pumps with different pump characteristics.

The energy and water consumption can be optimized by optimally adjusting the pressure and liquid flow rate values.

With the invention, a reversing device was created in a simple manner, with which the possibilities of influencing the course of the cleaning program are improved and thus a cleaning effect is optimally achieved in accordance with the degree of soiling of the items to be cleaned.

Claims

claims

1. reversing device, in particular for a dishwasher with a washing container with a hydraulic arrangement with at least two spray devices which act on the items to be cleaned which are arranged in the washing container by means of a liquid conveyed by a circulating pump, the conveyed liquid flowing through a reversing device, and wherein the reversing device has at least two exits for supplying the liquid to different spray devices, which can be opened or closed by means of an actuating element such that either one of the exits or a number of exits or all exits alternately in succession and / or continuously are open or closed, characterized in that the characteristic of the hydraulic arrangement and the characteristic of the circulation pump (7) are changed simultaneously or alternately.

2. Reversing device according to claim 1, characterized in that the characteristic of the hydraulic arrangement is changed by changing the flow of the liquid through the reversing device and the characteristic of the circulating pump by regulating the speed of the circulating pump (7).

3. Reversing device according to claim 1 or 2, characterized in that the adjusting element (21, 21 ') of the hydraulic arrangement has at least one opening (22) with a cross section which is different from the cross section of at least one further opening (23, 24).

4. Reversing device according to one of claims 1 to 3, characterized in that the at least one opening (22) with a different cross section compared to the cross section of the at least one further opening (23, 24) has a substantially smaller cross section.

5. Reversing device according to one of the preceding claims, characterized in that the opening (22) with the substantially smaller cross-section than the at least one further opening (23, 24) serves to supply the liquid to an upper spray device (5).

6. Reversing device according to one of the preceding claims, characterized in that the adjusting element (21, 21 ') is a disc which has at least one opening (22) with the substantially smaller cross-section compared to the at least one further opening (23, 24).

7. Reversing device according to one of the preceding claims, characterized in that the at least one larger opening (23) is used essentially for supplying the liquid to a lower spray device (6), but alternatively also for supplying the liquid to the upper spray device (5) can serve.

8. Reversing device according to one of the preceding claims, characterized in that two opposite, larger openings (23, 24) serve for the simultaneous supply of the liquid to an upper spray device (5) and a lower spray device (6).

9. reversing device according to one of the preceding claims, characterized in that closed areas (25) of the actuating element (21, 21 '), which bear in the closed positions at the corresponding outputs (14, 15) in a sealing manner, in each case a circumferential, in the direction of the outlets (14, 15) have a protruding sealing edge (26).

10. Reversing device according to one of the preceding claims, characterized in that the smaller opening (22) is surrounded by a sealing edge (26) which rises in the direction of the exits (14, 15).

11. Reversing device according to claim 1 or 2, characterized in that the speed of the circulation pump (7) is reduced or increased in predetermined sub-program sections of the washing program sequence.

2. Reversing device according to claim 1 or 2, characterized in that the speed of the circulation pump (7) is reduced or increased over the entire washing program sequence.