Abstract
A household dishwasher includes a dishwasher cavity, and a receptacle for items to be washed. The receptacle can be shifted into and at least partially out of the dishwasher cavity. An electric motor having a motor parameter is designed to shift in a driving state the receptacle into or at least partially out of the dishwasher cavity and is decoupled in a free-running state from the receptacle and/or disconnected from a power supply. A detection unit detects a blockage of the receptacle and/or a stop request of a user as a function of the motor parameter, and a switching unit switches the electric motor into the free-running state as a function of the detected blockage or the detected stop request.
Claims
1.-15 (canceled)
16. A household dishwasher, comprising; a dishwasher cavity; a receptacle for items to be washed, said receptacle designed to be shifted into and at least partially out of the dishwasher cavity; an electric motor having a motor parameter and designed to shift in a driving state the receptacle into or at least partially out of the dishwasher cavity and to be decoupled in a free-running state from the receptacle and/or to be disconnected from a power supply; a detection unit designed to detect a blockage of the receptacle and/or a stop request of a user as a function of the motor parameter; and a switching unit designed to switch the electric motor into the free-running state as a function of the detected blockage or the detected stop request.
17. The household dishwasher of claim 16, further comprising a regulating unit designed to regulate at least in the driving state the electric motor as a function of a regulating parameter.
18. The household dishwasher of claim 17, wherein the detection unit is designed to detect the blockage of the receptacle and/or the stop request of the user as a function of the regulating parameter.
19. The household dishwasher of claim 16, wherein the detection unit detects the blockage and/or the stop request as a function of a comparison of the motor parameter with a threshold value.
20. The household dishwasher of claim 19, wherein the threshold value has a value which is fixed or variable over time.
21. The household dishwasher of claim 17, wherein the detection unit detects the blockage and/or the stop request as a function of a comparison of the motor parameter with a threshold value which has a value which is variable over time, with the variable value being dependent on the motor parameter, the regulating parameter, a further parameter or a derivative of one or several of the motor parameter, the regulating parameter, and the further parameter.
22. The household dishwasher of claim 17, wherein the electric motor is regulated by a comparison of a target value with an actual value, with the regulating parameter being equal to the target value or the actual value, said detection unit detecting the blockage and/or the stop request as a function of the comparison.
23. The household dishwasher of claim 22, wherein the target value is a target position and the actual value is an actual position of the receptacle.
24. The household dishwasher of claim 21, wherein the further parameter is determined as a function of an actual position of the receptacle relative to a reference position of the receptacle.
25. The household dishwasher of claim 24, wherein the reference position has a value which is fixed or variable over time.
26. The household dishwasher of claim 25, wherein the variable value corresponds to the reference position of a respective start-up position of the receptacle.
27. The household dishwasher of claim 26, wherein the respective start-up position is a half extraction length.
28. The household dishwasher of claim 19, further comprising a machine learning unit designed to determine the threshold value as a function of learning data sets.
29. The household dishwasher of claim 16, further comprising a mechanical coupling element designed to decouple the receptacle in the free-running state from the electric motor or to disconnect the electric motor from the power supply.
30. The household dishwasher of claim 16, further comprising a telescopic extension designed to assist a shift of the receptacle into or at least partially out of the dishwasher cavity and including an element which is driven by the electric motor for shifting the receptacle.
31. The household dishwasher of claim 16, wherein the electric motor is a permanent-magnet synchronous motor.
32. A method for operating a household dishwasher, comprising: a) shifting a receptacle for items to be washed with the aid of an electric motor, which has a motor parameter and/or is regulated as a function of a regulating parameter; b) detecting a blockage of the receptacle or a stop request of a user as a function of the motor parameter or the regulating parameter; and c) decoupling the electric motor from the receptacle or disconnecting the electric motor from a power supply as a function of the detected blockage or the detected stop request.
Description
[0045] Further advantageous embodiments and aspects of the invention form the subject matter of the subclaims and of the exemplary embodiments of the invention that are described below. The invention is described in greater detail below using preferred embodiments with reference to the accompanying figures,
[0046] in which
[0047] FIG. 1 shows a schematic perspective view of an embodiment of a household dishwasher;
[0048] FIG. 2 shows a schematic side view of the household dishwasher;
[0049] FIG. 3 shows by way of example a time characteristic of a motor current under an external force application;
[0050] FIG. 4 shows a time characteristic of a motor current when the threshold value is exceeded as a result of the force application from FIG. 3;
[0051] FIG. 5 shows a time characteristic of a motor current with a threshold value which is variable over time;
[0052] FIG. 6 shows a schematic representation of a position regulating loop;
[0053] FIG. 7 shows a time characteristic of a motor current upon start-up of a receptacle for items to be washed with the threshold value which is variable over time;
[0054] FIG. 8 shows a time characteristic of a motor current when the threshold value from FIG. 7 is exceeded; and
[0055] FIG. 9 shows steps of a method for operating a household dishwasher.
[0056] In the figures, elements that are identical or have the same function have been provided with the same reference characters unless otherwise stated.
[0057] FIG. 1 shows a schematic perspective view of an embodiment of a household dishwasher 1. The household dishwasher 1 comprises a dishwasher cavity 2, which can be closed off by a door 3, in particular in a watertight manner. To this end, a sealing device can be provided between the door 3 and the dishwasher cavity 2. The dishwasher cavity 2 is preferably cuboid in shape. The dishwasher cavity 2 can be arranged in a housing of the household dishwasher 1. The dishwasher cavity 2 and the door 3 can form a washing compartment 4 for washing items to be washed.
[0058] The door 3 is shown in its opened position in FIG. 1. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided on a lower end of the door 3. A loading opening 6 of the dishwasher cavity 2 can be closed or opened with the aid of the door 3. The dishwasher cavity 2 has a base 7, a ceiling 8 arranged opposite to the base 7, a rear wall 9 arranged opposite to the closed door 3, and two side walls 10, 11 arranged opposite to one another. The base 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 can be manufactured from a stainless steel sheet, for example. Alternatively, the base 7 can be manufactured from a plastic material, for example.
[0059] The household dishwasher 1 also has at least one receptacle for items to be washed 12 to 14. A number of, for example three, receptacles for items to be washed 12 to 14 can preferably be provided, wherein the receptacle for items to be washed 12 can be a lower receptacle for items to be washed or a lower basket, the receptacle for items to be washed 13 can be an upper receptacle for items to be washed or an upper basket, and the receptacle for items to be washed 14 can be a cutlery drawer. As additionally shown in FIG. 1, the receptacles for items to be washed 12 to 14 are arranged one above the other in the dishwasher cavity 2. Each receptacle for items to be washed 12 to 14 can optionally be shifted into or out of the dishwasher cavity 2. In particular, each receptacle for items to be washed 12 to 14 can be inserted or retracted into the dishwasher cavity 2 in an insertion direction E (arrow) and extracted or extended out of the dishwasher cavity 2 against the insertion direction E (arrow) in an extraction direction A (arrow).
[0060] FIG. 2 shows the household dishwasher 1 in a schematic side view. The dishwasher 1 has a telescopic extension 15 to which the receptacle for items to be washed 13 is fastened. The dishwasher 1 further comprises an electric motor 16 for driving an element 17, for example a rail, of the telescopic extension 15. In a driving state of the electric motor 16, the receptacle for items to be washed 13 is extended out of and retracted into the dishwasher cavity 2. Here, the electric motor 16 is actively connected to the receptacle for items to be washed 13. A combination of toothed wheels (not shown) and toothed racks (not shown) is provided for the active connection, for example. The toothed wheels and toothed racks engage with one another and can be arranged for example on the receptacle for items to be washed 13 and/or on the telescopic extension 15.
[0061] As further illustrated in FIG. 2, the dishwasher 1 has a regulating unit 18 (optional), which regulates the electric motor 16 as a function of at least one regulating parameter. The regulating parameter can be for example a position of the receptacle for items to be washed 13. The dishwasher 1 also comprises a detection unit 19 for detecting a blockage of the receptacle for items to be washed 13 or a stop request of a user. The detection takes place as a function of the regulating parameter or a motor parameter The detection can also take place as a function of the regulating parameter and the motor parameter. The motor parameter is for example a motor current I, a motor voltage, a motor temperature or a motor torque. The regulating parameter can be in particular an extension path of the receptacle for items to be washed 13. Furthermore, the detection unit 19 can comprise a sensor (not shown) for detecting the motor parameter. Furthermore, the dishwasher 1 has a switching unit 20, which switches the electric motor 16 into a free-running state if the detection unit 19 detects the blockage of the receptacle for items to be washed 13 or the stop request of the user. The regulating unit 18, the detection unit 19 and the switching unit 20 are implemented for example as hardware and/or software on a central control device (not shown) of the dishwasher 1. This can be the same control device which is also responsible for selecting and carrying out a respective washing program.
[0062] In its free-running state, the electric motor 16 is not actively connected to the receptacle for items to be washed 13 in order to extend and retract the same. In the free-running state, the receptacle for items to be washed 13 can be moved manually by the user freely in the retraction direction E (arrow) and the extension direction A (arrow). A coupling element (not shown), such as for example a switchable freewheel, can be arranged between the electric motor 16 and the receptacle for items to be washed 13. The coupling element couples the electric motor 16 to the receptacle for items to be washed 13 in order to move the same. Upon detection of the blockage or the stop request, the switching unit 20 decouples the coupling element from the electric motor 16 so that the receptacle for items to be washed 13 can be moved freely. The free-running state of the electric motor 16 can also be achieved by the switching unit 20 disconnecting the electric motor 16 from the power supply, for which purpose the electric motor 16 can advantageously be embodied as a permanent-magnet synchronous motor. Disconnection from the power supply can take place for example via a relay (not shown).
[0063] Embodiments of the manner in which the blockage and the stop request of the user are determined by the detection unit 19 are now described below.
[0064] The stop request of the user is expressed for example by way of a force 21 (arrow) applied by the user onto the receptacle for items to be washed 13 when the same is extended or retracted. The force 21 (arrow) can also take effect on the receptacle for items to be washed 13 as a result of a blockage.
[0065] The case in which the receptacle for items to be washed 13 is extended is described below.
[0066] If the receptacle for items to be washed 13 is extended in the extension direction A (arrow) and becomes blocked or the user wants to stop the receptacle for items to be washed 13, the external force 21 (arrow) acts counter to the extension direction A (arrow) on the receptacle for items to be washed 13. So that the receptacle for items to be washed 13 can continue its movement in the extension direction A (arrow), the electric motor 16 must provide an additional force 22 (arrow) in order to overcome the external force 21 (arrow). To provide the force 22 (arrow), the electric motor 16 must apply a greater torque, which is achieved by an increase in a motor current I of the electric motor 16.
[0067] FIG. 3 shows a time characteristic of a motor current I before and during a sustained application of the external force 21 (arrow, hereinafter also external force application 21). The motor current I prior to the external force application 21 is referred to as I1, while the motor current I after the external force application 21 (arrow) is referred to as 12. The start time of the external force application 21 (arrow) is referred to as t1. The motor current I increases linearly from I1 to I2, but can also increase exponentially, for example. The increase in the motor current I3 takes place up to the time t2, from which the motor current I reaches the value I2 required in order to overcome the external force 21 (arrow). The time difference between the time t2 and the start of the force application t1 is referred to as t3.
[0068] As can further be seen in FIG. 3, the motor current I can also run dynamically between a current interval I4 and not along a fixed characteristic of the motor current I1 and 12. This can be the case for example on account of an undetermined or unknown load of the receptacle for items to be washed 13 or a dynamic behavior during the movement of the receptacle for items to be washed 13, such as during a start-up phase, as explained in more detail later. The lower limit of the motor current characteristic I within the current interval I4 is referred to as I5, while the upper limit of the motor current characteristic I within the current interval I4 is referred to as I6.
[0069] FIG. 4 shows a time characteristic of the motor current I and an increase in the motor current I3 as a result of the force application 21 (arrow). In order to avoid injury to the user or damage to the receptacle for items to be washed 13 or to the items to be washed (not shown), a fixed threshold value 23 is defined, for example stored on a storage facility (not shown) of the dishwasher 1. The detection unit 19 (FIG. 2) compares the motor current I with the threshold value 23. If the motor current I exceeds the threshold value 23, the detection unit 19 detects the blockage or the stop request.
[0070] In a further exemplary embodiment, the threshold value 23 can for example be adapted to a load state of the receptacle for items to be washed 13. If the weight of the receptacle for items to be washed 13 is increased, a higher motor current I3 is required in order to move the receptacle for items to be washed 13. So that the detection unit 19 does not incorrectly detect a blockage, the threshold value 23 is advantageously increased.
[0071] In a further exemplary embodiment, the threshold value 23 can have a value which is variable over time, as shown in FIG. 5. The threshold value 23 can be reduced if the motor current I3 increases too rapidly in the time difference t3. The reason for this is that a stop request of a user or a blockage is associated with a very sudden and thus rapid increase in the motor current I3.
[0072] FIG. 5 further shows a motor current characteristic I with a lower increase I3 and a higher threshold value 23, so that an increased motor current I2 is tolerated by the detection unit 19. A reason for this can be for example the start-up of the electric motor 16 and an increased current draw associated therewith. In order to consider the increase in the motor current I3 in the threshold value 23, the threshold value 23 is defined for example as a function of a time derivative of the motor current I.
[0073] In a further exemplary embodiment, a regulation of the electric motor 16 comprises a position regulating loop 24, which is illustrated in FIG. 6. The regulation compares a target value SW with an actual value IW. The regulating parameter-here the actual value DWis regulated by the regulation in order to minimize a difference DW between the target value SW and the actual value IW. The target value SW can be for example a target position of the receptacle for items to be washed 13. The actual value IW can be for example an actual position s of the receptacle for items to be washed 13. The position regulating loop from FIG. 6 comprises the regulating unit 18 from FIG. 2, which regulates the motor current I of the electric motor 16 from FIG. 2. Subsequently, the receptacle for items to be washed 13 is extended out of the dishwasher cavity 2 and in the process travels along an extension path s. A position of the receptacle for items to be washed 13 is determined for example via the extension path s. The position of the receptacle for items to be washed 13 is goes back into the position regulating loop 24 as the actual position IW or s, where it is compared with the target value SW.
[0074] On account of the external force application 21 (arrow) from FIG. 2, the difference DW between the target position SW and an actual position IW cannot be minimized by the position regulating loop 24 and even increases. So that the detection unit 19 detects a blockage or a stop request, the threshold value 23 can be defined for example as a function of the difference DW.
[0075] FIG. 7 shows a time characteristic of a motor current I at the start-up of the receptacle for items to be washed 13. The start-up phase s3 is described by an initial start-up position s1 and a final startup position s2. During the start-up s3 of the receptacle for items to be washed 13, the motor current I is increased. So as not to detect an incorrect blockage therein and to leave the external force 21 (arrow) constant over an entire extraction length 25 (FIG. 2) of the receptacle for items to be washed 13, the threshold value 23 is dependent both on the motor current I and on a reference position of the receptacle for items to be washed 13. Here, the reference position has a value which remains fixed or varies over time. The reference position can be a position of the receptacle for items to be washed 13 over the entire extraction length 25, for example the start-up position s1, as for example at half extraction length.
[0076] As shown in FIG. 7, the motor current I is limited by the threshold value 23. The threshold value 23 is dependent on the motor current I and the position of the receptacle for items to be washed 13, wherein the position over the extension path s of the receptacle for items to be washed 13 is determined and has a similar curve to the characteristic of the motor current I. The difference between the threshold value 23 and the motor current I remains constant. This difference corresponds to an additional motor current that is required in order to overcome the external force 21 (arrow).
[0077] FIG. 8 shows the time characteristic of a motor current I from FIG. 7 when the threshold value 23 from FIG. 7 is exceeded in the start-up phase s3 of the receptacle for items to be washed. This also makes it possible to detect the blockage and the stop request during the start-up phase s3.
[0078] FIG. 9 shows steps of a method for operating a household dishwasher. In a first step S1, the receptacle for items to be washed 13 is shifted with the aid of the electric motor 16. The electric motor 16 has at least one motor parameter I and is regulated as a function of at least one regulating parameter s. In a second step S2, the blockage of the receptacle for items to be washed 13 or the stop request of a user is regulated as a function of the motor parameter I or the regulating parameter s. In a third step S3, the electric motor 16 is decoupled from the receptacle for items to be washed 13 or disconnected from the power supply as a function of the detected blockage or the detected stop request.
[0079] In a further exemplary embodiment, the dishwasher 1 has a machine learning unit (not shown) for determining the threshold value 23 as a function of learning data sets. The threshold value 23 can be defined for example once only or continuously with new data sets.
[0080] Although the present invention has been described with reference to exemplary embodiments, it can be modified in numerous different ways.
REFERENCE CHARACTERS USED
[0081] 1 Household dishwasher [0082] 2 Dishwasher cavity [0083] 3 Door [0084] 4 Washing compartment [0085] 5 Pivot axis [0086] 6 Loading opening [0087] 7 Base [0088] 8 Ceiling [0089] 9 Rear wall [0090] 10 Side wall [0091] 11 Side wall [0092] 12 Receptacle for items to be washed [0093] 13 Receptacle for items to be washed [0094] 14 Receptacle for items to be washed [0095] 15 Telescopic extension [0096] 16 Electric motor [0097] 17 Element [0098] 18 Regulating unit [0099] 19 Detection unit [0100] 20 Switching unit [0101] 21 Force (arrow) [0102] 22 Force (arrow) [0103] 23 Threshold value [0104] 24 Regulating loop [0105] 25 Extraction length [0106] A Extraction direction (arrow) [0107] DW Difference [0108] E Insertion direction (arrow) [0109] I Motor current [0110] I1-16 Motor current [0111] IW Actual value; actual position [0112] S1 First step [0113] S2 Second step [0114] S3 Third step [0115] SW Target value; target position [0116] S Extension path; actual position [0117] s1 Position [0118] s2 Position [0119] s3 Start-up phase [0120] t Time [0121] t1 Time [0122] t2 Time [0123] t3 Time
