Lifting device, method for operating a lifting device and dishwasher

Abstract

Lifting device (17) for a dishwasher (1), in particular a household dishwasher, with a dishwashing basket (10), wherein the lifting device (17) has an electric drive unit (24) which is configured to move the dishwashing basket (10) between a starting position (P A ) and an end position (P E ) to move by means of raising or lowering, comprises a detection unit (40) for detecting a current consumption of the electrical drive device (24) over a displacement path (x) of the dishwashing dish intake (10) in the dishwasher (1) and a determination unit (41) for determining at least one state of the lifting device (17) as a function of the current consumption (I) of the drive device (24) detected over the displacement path (x).

Description

[0001] The present invention relates to a lifting device for a dishwasher, a method for operating such a lifting device and a dishwasher with such a lifting device.

[0002] DE 10 2013 226 910 A1 describes a lifting device for a dishware holder of a water-conducting household appliance, wherein the dishware holder can be selectively moved into or out of a washing container of the water-conducting household appliance, wherein the lifting device is designed to raise the dishware holder when it is moved out of the washing container and to lower it when it is moved into the washing container, wherein the lifting device has a drive device and a control device, wherein the control device is designed to control the drive device when the dishware holder is moved manually such that the drive device supports the manual movement of the dishware holder with an assisting force.

[0003] Further lifting devices or basket lifting systems are known from the documents DE 10 2012 107 993 A1, DE 20 2009 004 771 U1, EP 2 818 092 A1, WO 2014 / 102 367 A1 and WO 2014 / 102 374 A1.

[0004] An active rack lifting system with an active drive element comprising a motor and gear unit is shown in JP 2006-141 700 A. This describes a temporal evaluation of the drive element's drive current, which can be used to draw conclusions about fault conditions in the drive element. Such fault conditions include, for example, a blockage of the rack or washing container.

[0005] Against this background, an object of the present invention is to provide an improved lifting device.

[0006] Accordingly, a lifting device for a dishwasher, in particular a household dishwasher, with a dishware holder is proposed, wherein the lifting device comprises an electric drive device which is designed to displace the dishware holder between a starting position and an end position by means of raising or lowering, a detection unit for detecting a current consumption of the electric drive device over a displacement path of the dishware holder in the dishwasher and a determination unit for determining at least one state of the lifting device depending on the current consumption of the drive device detected over the displacement path.

[0007] The displacement path is defined as a path, specifically a distance, between the starting position of the dishware holder and its end position. Thus, the displacement path corresponds to the distance traveled by the dishware holder when raising or lowering it between the starting position and the end position.

[0008] Examples of the at least one state of the lifting device include the current position of the dishware holder in the washing tub, a fault state of the lifting device, and the current weight of the load in the dishware holder. A fault state of the lifting device occurs, for example, when the movement of the dishware holder is blocked.

[0009] In the present lifting device, the at least one state is determined by evaluating the current consumption of the electric drive device, which is measured over the displacement distance. Advantageously, no temporal evaluation of the current consumption is used. Consequently, the determination unit operates independently of the time parameter. In particular, position detection and load detection are provided based on the relationship between current and displacement.

[0010] This requires no additional sensors to be installed in the dishwasher. The proposed lifting device advantageously increases the safety of the entire dishwasher system.

[0011] According to one embodiment, the determination unit is configured to determine a position of the dishware holder in a washing container of the dishwasher, a fault condition of the lifting device and / or a current weight of a load held in the dishware holder as a function of the current consumption of the drive device detected over the displacement path.

[0012] A fault condition in the lifting device could be, for example, a blockage of the dishware holder during raising or lowering. Such a blockage can be caused, for example, by a user or even a child.

[0013] According to a further embodiment, the determination unit is configured to determine a fault condition of the lifting device as a function of a derivative of the detected current consumption according to the displacement path.

[0014] The current consumption of the electric drive system is a function of the displacement of the washware holder between the starting position and the end position. The derivative is, in particular, the first mathematical derivative of this function of the measured current consumption with respect to the displacement. Using the first derivative of this function is a simple and unambiguous means of determining fault conditions.

[0015] According to a further embodiment, the determination unit is configured to determine the at least one state of the lifting device as a function of a comparison of the current consumption detected over the displacement path with at least one reference curve for the current consumption of the electric drive device.

[0016] The use of reference curves creates a technically simple implementation for determining at least one state of the lifting device.

[0017] According to a further embodiment, a storage unit is provided for storing a plurality of different weight-specific reference curves for the current consumption of the electric drive device for the load of the dishware holder. The determination unit is configured to determine the current weight of the load accommodated in the dishware holder by comparing the detected current consumption with the weight-specific reference curves.

[0018] For example, based on the measured current consumption, one of the weight-specific reference curves can be selected from the plurality of stored weight-specific reference curves. Using the selected weight-specific reference curve, the weight of the load in the dishwashing rack can be determined.

[0019] According to a further embodiment, the lifting device comprises a storage unit for storing a plurality of different reference curves for the current consumption of the electric drive device, specific to the weight of the load in the dishware holder, a weight sensor for determining the current weight of the load accommodated in the dishware holder, and a selection unit for selecting one of the stored reference curves depending on the weight of the load determined by the weight sensor. The determination unit is configured to determine a fault condition of the lifting device by comparing the detected current consumption with the selected reference curve.

[0020] The selected reference curve represents, in particular, a setpoint curve. In contrast, the recorded current consumption represents an actual value curve. Depending on a difference between the actual value curve and the setpoint curve, a fault condition of the lifting device can be concluded.

[0021] According to a further embodiment, the lifting device comprises a weight sensor for determining a weight of the load accommodated in the dishware holder.

[0022] According to a further embodiment, the determination unit is configured to determine the at least one state of the lifting device as a function of the detected current consumption and the weight determined by the weight sensor.

[0023] By using the weight determined by the weight sensor in addition to the detected path-specific current consumption, the information content for determining at least one state of the lifting device is increased. Increasing the information content increases the accuracy and reliability of determining at least one state of the lifting device.

[0024] According to a further embodiment, a sensor device is provided for detecting the displacement path of the dishware holder in the dishwasher. The sensor device is preferably configured to detect the displacement path optically, acoustically, magnetically, or via a change in electrical resistance.

[0025] According to a further embodiment, the lifting device comprises a storage unit for storing a minimum reference curve for a minimum current consumption of the electric drive device and a maximum reference curve for a maximum current consumption of the electric drive device. The determination unit is configured to detect a fault condition of the lifting device if the detected current consumption is less than the stored minimum reference curve or greater than the stored maximum reference curve.

[0026] According to a further embodiment, the lifting device comprises a control device which is designed to control the electric drive device for raising or lowering the dishware holder depending on the determined at least one state of the lifting device.

[0027] The control device can be designed, in particular, as the central control device of the dishwasher. It can also be referred to as the electronics or central electronics of the dishwasher.

[0028] According to a further embodiment, the determination unit is integrated in the control device.

[0029] According to a further embodiment, the electric drive device comprises a servomotor. A servomotor is generally a special version of an electric motor in which a sensor device is present that enables the position of the electric motor shaft to be detected. In particular, the drive device can be a servomotor. This enables precise control of the drive device, since the servomotor can always transmit a rotational position of its drive shaft to the control device.

[0030] According to a further embodiment, the servo motor is arranged in or on a side wall of the dishwasher.

[0031] Preferably, the servomotor is arranged between a side wall of the washing container and the side wall of the dishwasher. In particular, the control device is also positioned on or in the side wall of the dishwasher. This results in a particularly space-saving design of the lifting device.

[0032] According to a further embodiment, the lifting device for a dishwasher is configured with an upper dishware receptacle and a lower dishware receptacle. The electric drive device is configured to displace the lower dishware receptacle between the starting position and the end position by raising or lowering it. The sensor device is configured to detect the displacement path of the lower dishware receptacle in the dishwasher. The detection unit is configured to detect the current consumption of the electric drive device over the displacement path of the lower dishware receptacle. The determination unit is configured to determine the at least one state of the lifting device as a function of the current consumption of the electric drive device detected over the displacement path of the lower dishware receptacle.

[0033] The upper dishware receptacle is provided in the dishwasher's wash tub above the lower dishware receptacle. A cutlery drawer of the dishwasher can be arranged above the upper dishware receptacle. The drive device is preferably configured to automatically raise the lower dishware receptacle from the starting position to the end position and to lower it from the end position to the starting position. This means that the lower dishware receptacle is moved without the application of any manual actuating force. Because the lifting device can be operated solely by applying the actuating force to the upper dishware receptacle, it is not necessary for a user to bend down to the lower dishware receptacle to operate the lifting device. This increases operating comfort.

[0034] In particular, the speed of movement of the lower dish rack when raising or lowering it is proportional to a change in the actuating force. For example, the speed of movement is directly proportional to the change in the actuating force. This means that the greater the actuating force and / or the further the upper dish rack is pushed into or pulled out of the wash tub, the greater the speed of movement of the lower dish rack.

[0035] The lifting device preferably further comprises at least one pivot arm which is pivotally attached to the washing container of the dishwasher and to the dishware holder. Preferably, four such pivot arms are assigned to the washing container, each arranged in pairs on a side of the washing container. In particular, the pivot arms are pivotally arranged on a guide device to which the lower dishware holder is attached. In particular, the drive device is arranged on the at least one pivot arm. The drive device preferably has a drive shaft which extends through a side wall of the washing container. A suitable sealing device can be provided between the drive shaft and the side wall. The drive shaft is connected in a rotationally fixed manner to a bearing point of the pivot arm. Preferably, one such drive device can be provided on each side of the lower dishware holder.Optionally, such a drive device can be provided on each of the swivel arms.

[0036] Furthermore, the control device is preferably designed to control the drive device in such a way that the lower dishware holder remains in its current position when the actuating force is removed.

[0037] The upper dish rack can be moved into or out of the wash tub by applying an actuating force, particularly a compressive or tensile force. As soon as the manual actuating force is no longer acting on the upper dish rack, the lower dish rack automatically remains in its current position. This prevents user injury from an unintentional movement of the lower dish rack.

[0038] Preferably, the control device is configured to control the drive device to raise the lower dishware holder when the upper dishware holder is moved into the washing container. The control device is further configured to control the drive device to lower the lower dishware holder when the upper dishware holder is moved out of the washing container.

[0039] This means that when the upper dishware holder is moved into the washing tub or when the actuating force in the form of a compressive force is applied to the upper dishware holder in the direction into the washing tub, the lower dishware holder is raised and when the upper dishware holder is moved out of the washing tub or when the actuating force in the form of a tensile force is applied to the upper dishware holder in the direction out of the washing tub, the lower dishware holder is lowered.

[0040] According to a further embodiment, the lifting device comprises a locking device which is designed to lock the upper dishware holder when raising or lowering the lower dishware holder in such a way that it is locked in the washing container in a linearly immovable manner.

[0041] This ensures that the upper dish rack always remains in the wash tub when the lower dish rack is raised or lowered. This prevents the lower dish rack from colliding with the upper dish rack.

[0042] According to a further embodiment, the locking device is designed to release the upper dishware holder only when the lower dishware holder is in the starting position.

[0043] The position of the lower dish rack can be detected using appropriate sensors. The lower dish rack can only be moved into or out of the wash tub when in its initial position.

[0044] According to a further embodiment, the locking device is designed to couple the upper dishware holder to the washing container in order to lock it.

[0045] In particular, the locking device is configured to positively couple the upper dishware holder to the washing container. The locking device can comprise a locking element, such as a bolt, which can be displaced by means of a magnetic coil. The locking element can be configured to positively engage an engagement portion provided on the washing container. The locking element can also be, for example, an electromagnet.

[0046] According to a further embodiment, the lifting device comprises a spring device which is designed to couple the locking device to the upper dishware holder.

[0047] The spring device can be a helical or cylindrical spring. Preferably, the spring device is positioned between the upper dishware holder and the locking device.

[0048] When lowering the lower dish rack, the manual actuation force acts against the spring force of the spring mechanism, compressing it. When raising the lower dish rack, the manual actuation force acts against the spring force of the spring mechanism, stretching it.

[0049] Furthermore, a dishwasher is proposed with a washing container in which a dishware holder can be arranged, and with a lifting device as described above. The dishwasher is, in particular, a household dishwasher.

[0050] The lower dishware holder can also be called the lower basket and the upper dishware holder can also be called the upper basket.

[0051] Furthermore, a method for operating a lifting device for a dishwasher, in particular a household dishwasher, with a dishware holder is proposed, wherein the lifting device has an electric drive device configured to displace the dishware holder between a starting position and an end position by raising or lowering. The method comprises the following steps: detecting a displacement path of the dishware holder in the dishwasher, detecting a current consumption of the electric drive device over the displacement path, and determining at least one state of the lifting device depending on the current consumption of the drive device detected over the displacement path.

[0052] The embodiments and features described for the proposed device apply accordingly to the proposed method.

[0053] Furthermore, a computer program product is proposed which causes the method as explained above to be carried out on a program-controlled device.

[0054] A computer program product, such as a computer program means, can be provided or delivered, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file from a server in a network. This can be done, for example, in a wireless communications network by transmitting a corresponding file with the computer program product or the computer program means.

[0055] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments that are not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0056] Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic sectional view of an embodiment of a dishwasher; Fig. 2 shows a further schematic sectional view of the dishwasher according to Fig. 1; Fig. 3 shows a schematic partial sectional view of the dishwasher according to Fig. 1; Fig. 4 shows a diagram illustrating the displacement-dependent current consumption of the electric drive device of the lifting device of the Fig. 1; Fig. 5 shows a diagram illustrating the displacement-dependent current consumption of the electric drive device of the lifting device in a fault condition; Fig. 6 shows a diagram illustrating various weight-specific reference curves for the current consumption of the electric drive device; Fig. 7 shows a diagram illustrating an example of the displacement-dependent current consumption of the electric drive device of the lifting device, as well as a minimum reference curve for a minimum current consumption of the electric drive device and a maximum reference curve for a maximum current consumption of the electric drive device; and Fig. 8 shows an embodiment of a method for operating a lifting device for a dishwasher.

[0057] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

[0058] The Fig. 1 and Fig. 2 each show a schematic sectional view of an embodiment of a dishwasher 1. The dishwasher 1 is preferably a household dishwasher. The dishwasher 1 has a washing container 2, which can be closed by a door 3, in particular in a watertight manner. For this purpose, a sealing device can be provided between the door 3 and the washing container 2. The washing container 2 and the door 3 can form a washing chamber 4 of the dishwasher 1 for washing dishes. The door 3 is in the Fig. 1 and Fig. 2 is shown in its open position. The door 3 can be closed or opened by pivoting about a pivot axis provided at a lower end of the door 3.

[0059] The washing container 2 has a base 5, a cover 6 arranged opposite the base 5 and a rear wall 7 arranged opposite the door 3. Furthermore, the washing container 2 has two side walls 8, 9 arranged opposite each other. The side wall 9 is in the Fig. 1 and Fig. 2 is only partially shown. The rinsing container 2 is preferably cuboid-shaped. The rinsing container 2 is preferably made of a metal material, in particular of a metal sheet. For example, the rinsing container 2 can be made of a stainless steel sheet. The base 5 can also be made of a plastic material.

[0060] The dishwasher 1 has a lower basket or a lower dishware holder 10. Furthermore, the dishwasher 1 has an upper basket or an upper dishware holder 11. The dishware holders 10, 11 are preferably arranged one above the other in the washing container 2. The upper dishware holder 11 is in the orientation of the Fig. 1 and Fig. 2 is arranged above the lower dishware receptacle 10. Furthermore, the dishwasher 1 can comprise a cutlery drawer (not shown) arranged above the upper dishware receptacle 11. The dishware receptacles 10, 11 are preferably box-shaped. The bottoms and walls of the dishware receptacles 10, 11 are grid-shaped. Each dishware receptacle 10, 11 can be moved in an insertion direction E either into the washing tub 2 or out of it in a pull-out direction A, opposite to the insertion direction E. A handle 12 can be provided on each of the dishware receptacles 10, 11.

[0061] For this purpose, the washware holders 10, 11 can be moved into or out of the washing container 2 by means of guide devices 13. Fig. 1 and Fig. 2, only the guide device 13 of the lower dishware holder 10 is shown. Preferably, each dishware holder 10, 11 is assigned two such guide devices 13, which are arranged on either side of the dishware holders 10, 11. The dishware holders 10, 11 can each be suspended in the guide devices 13 assigned to them. Each guide device 13 can have a first guide rail 14, a second guide rail 15, and a guide rail 16 arranged between the first guide rail 14 and the second guide rail 15. The lower dishware holder 10 is preferably fastened to and / or suspended in the second guide rail 15. The guide rail 16 is movable relative to the guide rails 14, 15.

[0062] The dishwasher 1 further comprises a lifting device 17 for the lower dishware holder 10. The lifting device 17 is designed to lift the lower dishware holder 10, when it is completely moved out of the washing container 2, from a Fig. 1 shown starting position P A into one in the Fig. 2 shown end position P E This means that the lower dishware holder 10 can only be moved in the starting position P A into or out of the washing container 2. In particular, the lifting device 17 is designed to move the lower dishware holder 10 from the starting position P A to the end position P E to lift and from the end position P E to the starting position P A to lower.

[0063] The lifting device 17 comprises at least a first pivot arm 18 and a pivot arm 19 arranged at a distance from the first pivot arm 18. The pivot arms 18, 19 are each pivotably attached to one of the side walls 8, 9 of the washing container 2 by means of bearing points 20, 21. In particular, the bearing points 20, 21 are fixed bearings. The bearing point 20 is preferably arranged at the same height in the vertical direction as the bearing point 21. The pivot arms 18, 19 are further pivotably attached to the guide device 13 of the lower dishware holder 10 and in particular to the first guide rail 14 by means of bearing points 22, 23. Fig. 1, the pivot arms 18, 19 are positioned vertically. This means that the pivot arms 18, 19 are in the starting position P A the lower dishware holder 10 in a vertical arrangement.

[0064] The lifting device 17 further comprises a Fig. 3 and a control device 25, which can be connected to the drive device 24 via a control line 26. The drive device 24 comprises a servomotor or is designed as a servomotor. A power supply to the drive device 24 can also be provided via the control line 26. The drive device 24 and / or the control device 25 are arranged in or on a side wall 27 of a housing 28 of the dishwasher 1. As the Fig. As shown in Figure 3, the drive device 24 and the control device 25 are positioned between the side wall 8 of the washing container 2 and the side wall 27 of the housing 28 of the dishwasher 1. The control device 25 can also be integrated into the drive device 24. This results in a particularly compact design of the lifting device 17.

[0065] The drive device 24 comprises a drive shaft 29, which is guided through the side wall 8 of the washing container 2 into the washing chamber 4. A suitable sealing device can be provided between the drive shaft 29 and the side wall 8. The drive shaft 29 is preferably connected to the first pivot arm 18 at the bearing point 20 thereof in a rotationally fixed manner, so that the drive device 24 can apply a torque to the first pivot arm 18. Alternatively or additionally, such a drive device 24 can also be provided for the second pivot arm 19. Such drive devices 24 can be provided on both side walls 8, 9 of the washing container 2. The drive device 24 is designed to move the lower dishware holder 10 from the starting position P without any manual assistance. A to the end position P E to lift or from the end position P E to the starting position P A to lower.

[0066] Now returning to the Fig. 1 and Fig. 2, the lifting device 17 further comprises a control lever or drag lever 30. Preferably, one such drag lever 30 is provided on each side of the lower dishware holder 10. The drag lever 30 is rotatably mounted on the washing container 2 and in particular on one of the side walls 8, 9 in each case by means of a bearing point 31. The bearing point 31 is arranged vertically below the bearing points 20, 21 of the pivot arms 18, 19. The drag lever 30 is further mounted on the lower dishware holder 10 by means of a bearing point 32. The drag lever 30 can be configured to lock the lower dishware holder 10 during raising or lowering such that it cannot be displaced into or out of the washing container 2. For this purpose, the drag lever 30 can comprise a locking or locking device.In particular, the rocker arm 30 can be configured to fix the bearing point 32 of the rocker arm 30 provided on the lower dishware holder 10 when raising and lowering the lower dishware holder 10, so that the bearing point 32 is pivotable relative to the lower dishware holder 10 but cannot be linearly displaced. This means that when raising or lowering the lower dishware holder 10, the bearing point 32 is only pivotable relative to the lower dishware holder 10. Only in the starting position P. A The bearing point 32 is released, allowing the lower dishware holder 10 to be moved linearly relative to the bearing point 32. The rocker arm 30 is optional.

[0067] The lifting device 17 further comprises a locking or locking device 35, which is designed to lock the upper dishware holder 11 when raising or lowering the lower dishware holder 10 such that the upper dishware holder 11 is locked in the washing container 2 in a linearly immovable manner, so that it can only be displaced slightly in the extension direction A and in the insertion direction E to operate the lifting device 17. In particular, the locking device 35 is designed to release the upper dishware holder 11 only when the lower dishware holder 10 is in the starting position P AThe locking device 35 can comprise a locking element. The locking device 35 is configured to electromechanically lock the upper dishware holder 11 in the washing compartment 2. For example, the locking device 35 can have a magnetic coil configured to displace the locking element, which can be a bolt, for example, in order to bring it into positive engagement with an engagement portion provided on the rear wall 7 of the washing compartment 2. The locking element can also be an electromagnet configured to firmly couple the locking device 35 to the rear wall 7.

[0068] The lifting device 17 further comprises a spring device that couples the locking device 35 to the upper dishware holder 11. For example, the spring device can be a cylindrical spring. The spring device is arranged between the rear wall 34 of the upper dishware holder and a rear wall of the locking device 35. For example, the spring device 37 can be fixedly mounted to the rear walls.

[0069] The functionality of the lifting device 17 is explained below using the Fig. 1 to 7, to which reference is also made. To move the lower dishware holder 10 from the starting position P A to the end position P E the lower dishware holder 10 is first completely moved out of the washing container 2 so that the lower dishware holder 10 is in the starting position P AWhether the lower dishware holder 10 has been completely moved out of the washing tub 2 can be determined using appropriate sensors. The control device 25 is now configured to actuate the drive device 24 to raise or lower the lower dishware holder 10 when the upper dishware holder 11 is manually moved in the washing tub 2.

[0070] A first manual actuating force F1, in particular a pressure force, is first applied to the upper dishware holder 11, which has been moved into the washing tub 2. The actuating force F1 acts in the direction of the rear wall 7. In this case, the locking device 35 is still arranged at a distance from the rear wall 7 of the washing tub 2, and the upper dishware holder 11 is not yet locked in the washing tub 2. The locking device 35 is not locked. By applying the actuating force F1, the upper dishware holder 11 is displaced further into the washing tub 2 until the locking device 35 contacts the rear wall 7. The locking device 35 is still not locked.

[0071] By further displacing the upper dishware holder 11 into the washing container 2, the spring device is compressed. In this case, the actuating force F1 acts against a spring force of the spring device. As soon as a lower threshold value of a displacement path of the upper dishware holder 11 is undershot, the locking device 35 is activated and the locking element couples the locking device 35 to the rear wall 7 of the washing container 2. In addition, as soon as the locking device 35 is locked, the drive device 24 is controlled by means of the control device 25, so that the lower dishware holder 10 is moved from the initial position P A to the end position P E is raised.

[0072] The smaller the displacement path and / or the greater the actuating force F1, the greater the movement speed when lifting the lower dishware holder 10. The prerequisite for locking the upper dishware holder 11 and activating the drive device 24 is that the lower dishware holder 10 is fully extended. This is ensured by the sensors described above. As soon as the actuating force F1 is no longer applied to the upper dishware holder 11, the lower dishware holder 10 remains in its current position. For this purpose, a locking device, for example a self-locking worm gear associated with the drive device 24, can be provided to lock the lower dishware holder 10.

[0073] If a second manual actuating force F2, in particular a tensile force, is applied to the locked upper dishware holder 11, directed away from the rear wall 7, and an upper threshold value of the displacement path is exceeded, the lower dishware holder 10 is moved from the end position P E to the starting position P A As soon as the lower dishware holder 10 reaches the starting position P A has been reached, the locking device 35 is unlocked or released, so that the upper dishware holder 11 is no longer locked in the washing container 2 and can be moved out of it. If, as long as the upper dishware holder 11 is locked, no actuating force F1, F2 is exerted on it, the drive device 24 is deactivated and the lower dishware holder 10 remains in its current position. For this purpose, the drive device 24 can comprise the aforementioned self-locking worm gear.

[0074] The lifting device 17 further comprises a sensor device 39 for directly detecting the actuating force F1, F2. The sensor device 39 can be provided on the washing container 2, the upper dishware receptacle 11, or on the handle 12 of the upper dishware receptacle 11. Preferably, the sensor device 39 is operatively connected to the handle 12, so that the actuating force F1, F2 can be detected as soon as it is applied to the handle 12. The sensor device 33 can be referred to as the first sensor device 33, and the sensor device 39 can be referred to as the second sensor device 39.

[0075] Compared to conventional solutions, the lifting device 17 has the advantage that a user does not have to bend down to the lower dishware holder 10 to operate the lifting device 17. The lifting device 17 can always be operated at the upper dishware holder 11, regardless of the position of the lower dishware holder 10. In particular, the lifting device 17 is operated using the handle 12 of the upper dishware holder 11. Furthermore, it is not necessary to attach additional buttons or sensor fields to the dishwasher 1 for operating the lifting device 17. Since the lifting device 17 can only be activated to raise or lower the lower dishware holder 10 when the upper dishware holder 11 is completely located in the washing tub 2, a collision between the lower dishware holder 10 and the upper dishware holder 11 is ruled out.Furthermore, no data and / or energy transmission into the rinsing chamber 4 of the rinsing container 2 is required.

[0076] The drive device 24 of the Fig. 3 comprises a detection unit 40 which is designed to detect a current current consumption of the electric drive device 24 over a displacement path x of the dishware holder 10 in the dishwasher 1. For this purpose, the Fig. 4 a diagram illustrating the displacement-dependent current consumption I of the electric drive device 24 of the lifting device 17.

[0077] Furthermore, the control device 25 comprises a determination unit 41 for determining at least one state of the lifting device 17 as a function of the current consumption I of the electric drive device 24 detected over the displacement path x.

[0078] Examples of the at least one state that can be determined by the determination unit 41 are the position of the lower dishware holder 10 in the washing container 2, an error state of the lifting device 17 and a current weight of a load held in the lower dishware holder 10.

[0079] For example, the determination unit 41 is configured to determine a fault condition of the lifting device 17 as a function of a first derivative of the detected current consumption I with respect to the displacement path x. For this purpose, the Fig. 5 a diagram to illustrate the displacement path dependent current consumption I of the electric drive device 24 in the event of a fault condition, which is indicated by the circuit 501 in Fig. 5. In the area of ​​circle 501, the gradient of the current current consumption I changes. This change in the gradient can be determined particularly easily by the first mathematical derivative of the detected current consumption I with respect to the displacement path x. In other words, the error state is detected here via the derivative of the motor current of the electric drive device 24 over the path x. If, for example, during the movement of the lower dishware holder 10, the current I or the current consumption I deviates from a reference curve or standard curve, for example if a child gets caught on the lower dishware holder, this is detected and the control device 24 can react accordingly, for example by switching off the drive device 24 or retracting the lower dishware holder 10.

[0080] In addition, the determination unit 41 can be configured to determine the at least one state of the lifting device 17 as a function of a comparison of the current consumption I detected over the displacement path x with at least one reference curve K1 - K5 for the current consumption I of the electric drive device 24. Examples of this are shown in the Fig. 6 and Fig. 7.

[0081] The Fig. 6 shows a diagram illustrating various weight-specific reference curves K1, K2, and K3 for the current consumption of the electric drive device 24. Reference curve K1 is an example of a light load, reference curve K2 is an example of a medium-heavy load, and reference curve K3 is an example of a heavy load. The weight-specific reference curves K1-K3 are stored, for example, in a memory device 42, which is integrated, for example, in the control unit 25. The determination unit 41 can be configured to determine the current weight of the load accommodated in the washware holder 10 by comparing the currently recorded current consumption I with the weight-specific reference curves K1-K3. The currently recorded current consumption I is used to determine the respective current reference curve K1, K2, or K3.The current weight of the load is then determined using the reference curve K1, K2, or K3 selected in this way.

[0082] Furthermore, it is also possible to use a weight sensor (not shown). The weight sensor can be configured to determine a current weight of the load accommodated in the lower dishware holder 10. Furthermore, a selection unit 43 integrated in the control device 25 can be configured to select one of the stored reference curves K1-K3 depending on the weight of the load determined by the weight sensor. The determination unit 41 can then be configured to determine an error state of the lifting device 17 by comparing the currently detected current consumption I with the selected reference curve K1, K2, or K3. In this embodiment, the selected reference curve K1, K2, or K3 specifies a target value curve, whereas the currently detected current consumption I represents an actual value curve.Depending on a deviation of the actual value curve from the setpoint value curve, an error condition of the lifting device 17 can be detected.

[0083] Furthermore, the weight of the load determined by the weight sensor can be used to increase the information content for detecting a state of the lifting device 17. The determination unit 41 can be configured to determine the at least one state of the lifting device 17 as a function of the detected current consumption I and the weight determined by the weight sensor.

[0084] Furthermore, Fig. 7 a diagram to illustrate an example of the displacement path-dependent current consumption I of the electric drive device 24 as well as a minimum reference curve K4 for a minimum current consumption of the electric drive device 24 and a maximum reference curve K5 for a maximum current consumption of the electric drive device 24. The determination unit 41 is then configured to determine a fault condition of the lifting device 17 if the detected current consumption is smaller than the stored minimum reference curve K4 or larger than the stored maximum reference curve K5. In the example of Fig. 7, the currently detected current consumption I intersects the maximum reference curve K5 at the exemplary displacement path x1. Consequently, it is determined that an error condition exists at the displacement path x1. For example, the control device 25 can react to this detected error condition by retracting the lower dishware holder 10 by means of the lifting device 17.

[0085] In Fig. 8 shows an embodiment of a method for operating a lifting device 17 for a dishwasher 1. An example of such a lifting device is shown in the Fig. 1 and Fig. 2. The dishwasher 1 is, for example, a household dishwasher and comprises a dishware holder 10. The lifting device 17 comprises an electric drive device 24, which is designed to move the dishware holder 10 between a starting position P A and an end position P Eby lifting or lowering. The example of the method of Fig. 8 includes the following steps 801, 802 and 803:

[0086] In step 801, a displacement path x of the dishware holder 10 in the dishwasher 1 is recorded.

[0087] In step 802, a current consumption I of the electric drive device 24 is recorded over the displacement path x.

[0088] In step 803, at least one state of the lifting device 17 is determined as a function of the current consumption I of the drive device 24 detected over the displacement path x.

[0089] Although the present invention has been described using exemplary embodiments, it is capable of being modified in many ways. For example, the Fig. 1 and Fig.2 a dishwasher 1 with a lower dishware holder 10 and an upper dishware holder 11. The lifting device 17 can also be used for a dishwasher with only a single dishware holder. Reference symbols used: 1 dishwasher 2 rinsing containers 3 Door 4 rinsing chamber 5 Floor 6 blanket 7 Rear wall 8 Side wall 9 Side wall 10 Dishwasher holder 11 Dishwasher drawer 12 Handle 13 Guide device 14 Guide rail 15 Guide rail 16 guide rail 17 Lifting device 18 Swivel arm 19 Swivel arm 20 storage location 21 storage location 22 storage location 23 storage location 24 electric drive device 25 Control device 26 Control line 27 Side wall 28 housings 29 Drive shaft 30 rocker arms 31 storage location 32 storage location 33 Sensor device 34 Rear wall 35 Locking device 39 Sensor device 40 recording units 41 Determination unit 42 storage unit 43 Selection unit 501 Circle 801 Process step 802 Process step 803 Process step A Extension direction E Insertion direction F1 actuation force F2 actuation force I Current consumption K1 weight-specific reference curve K2 weight-specific reference curve K3 weight-specific reference curve K4 minimum reference curve K5 maximum reference curve P A Starting position P E Final position x Relocation path

Claims

[1] Lifting device (17) for a dishwasher (1), in particular a household dishwasher, with a dishware holder (10), wherein the lifting device (17) comprises an electric drive device (24) which is designed to move the dishware holder (10) between a starting position (P A ) and an end position (P E ) by means of raising or lowering, a detection unit (40) for detecting a current consumption of the electric drive device (24) over a displacement path (x) of the washware holder (10) in the dishwasher (1) and a determination unit (41) for determining at least one state of the lifting device (17) depending on the current consumption (I) of the drive device (24) detected over the displacement path (x). [2] Lifting device according to claim 1, characterized byin that the determination unit (41) is designed to determine a position of the dishware holder (10) in a washing container (2) of the dishwasher (1), a fault state of the lifting device (17) and / or a current weight of a load held in the dishware holder (10) as a function of the current consumption (I) of the drive device (24) detected over the displacement path (x). [3] Lifting device according to claim 1 or 2, characterized by that the determination unit (41) is designed to determine a fault condition of the lifting device (17) as a function of a derivative of the detected current consumption (I) according to the displacement path (x). [4] Lifting device according to one of claims 1 to 3, characterized byin that the determination unit (41) is designed to determine the at least one state of the lifting device (17) as a function of a comparison of the current consumption (I) detected over the displacement path (x) with at least one reference curve (K1 - K5) for the current consumption (I) of the electric drive device (24). [5] Lifting device according to one of claims 1 to 4, characterized by a storage unit (42) for storing a plurality of different weight-specific reference curves (K1 - K3) for the current consumption (I) of the electric drive device (24) for the loading of the dishware holder (10), wherein the determination unit (41) is designed to determine the current weight of the load accommodated in the dishware holder (10) by means of a comparison of the detected current consumption (I) with the weight-specific reference curves (K1 - K3). [6] Lifting device according to one of claims 1 to 5, characterized bya storage unit (42) for storing a plurality of different reference curves (K1 - K3) for the current consumption (I) of the electric drive device (24), which reference curves are specific to the weight of the load in the dishware holder, a weight sensor for determining a current weight of the load held in the dishware holder, and a selection unit (43) for selecting one of the stored reference curves (K1 - K3) depending on the weight of the load determined by the weight sensor, wherein the determination unit (41) is configured to determine a fault state of the lifting device (17) by comparing the detected current consumption (I) with the selected reference curve (K1 - K3). [7] Lifting device according to one of claims 1 to 6, characterized bya weight sensor for determining a weight of the load accommodated in the dishware holder (10), wherein the determination unit (41) is configured to determine the at least one state of the lifting device (17) as a function of the detected current consumption (I) and the weight determined by the weight sensor. [8] Lifting device according to one of claims 1 to 7, characterized by a sensor device (33) for detecting the displacement path (x) of the dishware holder (10) in the dishwasher (1). [9] Lifting device according to one of claims 1 to 8, characterized bya storage unit (42) for storing a minimum reference curve (K4) for a minimum current consumption of the electric drive device (24) and a maximum reference curve (K5) for a maximum current consumption of the electric drive device (24), wherein the determination unit (41) is configured to determine a fault condition of the lifting device (17) if the detected current consumption is less than the stored minimum reference curve (K4) or greater than the stored maximum reference curve (K5). [10] Lifting device according to one of claims 1 to 9, characterized by a control device (25) which is designed to control the electric drive device (24) for raising or lowering the dishware holder (10) depending on the determined at least one state of the lifting device (17). [11] Lifting device according to claim 10, characterized bythat the determination unit (41) is integrated in the control device (25). [12] Lifting device according to one of claims 1 to 11, characterized by that the electric drive device (24) has a servo motor. [13] Lifting device according to one of claims 1 to 12, characterized by that the lifting device (17) for a dishwasher (1) is designed with an upper dishware holder (11) and a lower dishware holder (10), wherein the electric drive device (24) is designed to move the lower dishware holder (10) between the starting position (P A ) and the final position (P E) by means of raising or lowering, wherein the sensor device (33) is designed to detect the displacement path (x) of the lower dishware holder (10) in the dishwasher (1), wherein the detection unit (40) is designed to detect the current consumption (I) of the electric drive device (24) over the displacement path (x) of the lower dishware holder (10), and wherein the determination unit (41) is designed to determine the at least one state of the lifting device (17) as a function of the current consumption (I) of the electric drive device (24) detected over the displacement path (x) of the lower dishware holder (10). [14] Dishwasher (1), in particular a household dishwasher with a washing container (2) in which a dishware holder (10) can be arranged, and a lifting device (17) according to one of claims 1 to 13. [15] Method for operating a lifting device (17) for a dishwasher (1), in particular a household dishwasher, with a dishware holder (10), wherein the lifting device (17) has an electric drive device (24) which is designed to move the dishware holder (10) between a starting position (P A ) and an end position (P E ) by lifting or lowering, with: Detecting (801) a displacement path (x) of the dishware holder (10) in the dishwasher (1), Detecting (802) a current consumption (I) of the electric drive device (24) over the displacement path (x), and Determining (803) at least one state of the lifting device (17) as a function of the current consumption (I) of the drive device (24) detected over the displacement path (x).

Images