Household appliance, in particular dishwasher

Abstract

The invention relates to a household appliance, in particular a dishwasher, comprising an appliance container (3) which provides a treatment chamber (4) and has a feed opening (5) for accessing the treatment chamber (4), said feed opening being closable by means of an appliance door (6) which is rotatably mounted about a pivot axis, and a motor unit (15) which is operatively connected to the appliance door (6) and by means of which the appliance door (6) can be converted from an open position into a closure position, which closes the feed opening (5), and / or from the closure position into an open position. The invention is characterized by a sensor unit (22) which is designed to detect the rotational speed of a motor shaft (17) of the motor unit (15).

Description

[0001] Description

[0002] Household appliance, especially dishwasher

[0003] The invention relates to a household appliance, in particular a dishwasher, with an appliance container providing a treatment chamber, which has a loading opening for access to the treatment chamber, which can be closed by means of an appliance door mounted so as to be rotatable about a pivot axis, and with a motor unit which is operatively connected to the appliance door and by means of which the appliance door can be moved from an open position into a closed position closing the loading opening and / or from the closed position into an open position.

[0004] Household appliances in general, and water-using household appliances in particular, are well known in the art, so a separate written reference is not required here. Reference is therefore made, by way of example, to EP 2 636 355 B1, which discloses a household appliance in the specific configuration of a dishwasher.

[0005] “Household appliances” within the meaning of the invention include not only water-conducting household appliances such as dishwashers, washing machines and / or dryers, but also refrigerators, freezers, ovens, microwaves, steamers and / or the like.

[0006] A household appliance of this type has a housing that houses a container, which in turn provides a treatment chamber. This treatment chamber, when used as intended, serves to hold items that, in the case of a dishwasher, are items to be washed, such as dishes, cutlery, and / or the like.

[0007] To allow user access to the treatment chamber, the appliance container features a loading opening. This can be closed with a door, which, in the case of a water-using household appliance, is typically fluid-tight.

[0008] The appliance door is hinged to the housing and pivots, usually around a horizontal pivot axis. Unlike the dishwasher known from EP 2 636 355 B1, a household appliance of this type has a motor unit for motor-driven operation of the appliance door. This motor unit is operatively connected to the appliance door via a power transmission device, and the appliance door can be moved from an open position to a closed position, which closes the loading opening, by means of the motor unit.

[0009] The appliance door is typically vertically oriented when closed, whereas it is horizontal when the loading opening is fully open. A dishwasher equipped with such a motor unit is known, for example, from DE 102021 100 347 A1.

[0010] The use of a motor unit for at least motor-driven closing of the appliance door offers the user the advantage of simplified handling. Remote control of the appliance door is also possible, for example, via a mobile device carried by the user. A disadvantage, however, is that uncontrolled blockages can occur, for example, if a dishwashing basket is not fully retracted, preventing the appliance door from closing. Furthermore, there is a risk that the user's limbs, particularly hands and / or fingers, could accidentally enter the closing gap between the appliance door and the appliance housing, which poses a safety risk.

[0011] To overcome this problem, DE 10 2021 100 347 A1 proposes recording the movement of the appliance door as a temporal change in the appliance door position and comparing the resulting actual value with a predefined target value. This allows the motor unit to be shut down if the actual value deviates too significantly from the target value. As a result, an unwanted blocking of the appliance door can be reliably prevented by reliably shutting down the motor unit when a sensor detects an actual position of the appliance door that deviates from the target position.

[0012] Another measuring arrangement for detecting the position of a device door of a

[0013] A dishwasher is known from DE 102021 206 785 B4. According to this previously known measuring arrangement, a sensor is provided that interacts with a movable component of the appliance door. This movable component of the appliance door can be a pulley, a cable interacting with the appliance door, a return spring interacting with the appliance door, and / or the like. The measuring arrangement is designed to determine at least one door parameter based on a relative movement of the movable component of the appliance door and the sensor. According to DE 102021 206 785 B4, the movement of the appliance door is not recorded as a temporal change in the appliance position, but rather the relative movement of a movable component of the appliance door is determined.

[0014] Although both previously known sensor devices have proven themselves in everyday practical use, there is still room for improvement. In particular, the aim is to create an even more improved anti-pinch protection system. Therefore, the object of the invention is to further develop the design of a household appliance of the type mentioned above to enable even better sensing of an unwanted blocking position.

[0015] To achieve this, the invention proposes a household appliance of the type mentioned above, which is characterized by a sensor unit which is designed to detect the rotational speed of a motor shaft of the motor unit.

[0016] The household appliance, which can be designed in particular as a dishwasher, comprises an appliance container providing a treatment chamber, which has a loading opening for access to the treatment chamber, which can be closed by means of an appliance door mounted so as to be rotatable about a pivot axis, and a drive device which has a motor unit which is operatively connected to the appliance door and by means of which the appliance door can be moved from an open position into a closed position closing the loading opening and / or from the closed position into an open position.

[0017] In contrast to the prior art, according to the invention, neither the movement of the appliance door nor the relative movement of a movable component of the appliance door is detected, but rather the rotational speed of a motor shaft of the motor unit operatively connected to the appliance door. The embodiment according to the invention therefore differs from the prior art in particular in that, to detect a possible blockage position, it is not components moved by the motor unit, such as the appliance door itself or movable components interacting with it, that are detected, but rather the rotational speed of the motor unit moving the components. The decisive disadvantage of the solutions known from the prior art is that the components involved and driven by the motor unit only move comparatively slowly, so that sensory scanning of this movement cannot be carried out with very high resolution or sensitivity.The inventive design provides a remedy for this problem, as the speed of a relatively fast-rotating motor shaft of the motor unit is detected by a sensor. This creates a much more precise anti-pinch protection system than the prior art, further improving operational safety during intended use.

[0018] All of the prior art solutions have in common the need to sense the movement of a motor-driven component. If no movement is detected, the motor unit is stopped, as this could indicate a jamming or crushing event. Components to be sensed in this context include, for example, a control lever on the appliance door, a force transmission device operatively connected to it, such as a cable, a spring interacting with it, a pulley interacting with the cable, and / or the appliance door itself. The problem with monitoring all of these components is that, when used as intended, their movement is comparatively small, so the associated sensing is very rough. As a result, only very inaccurate monitoring of anti-pinch and / or anti-crushing protection is possible.The special feature of the invention is that the speed of the motor unit, i.e., a motor shaft of the motor unit, is sensed. Thus, in a departure from the prior art, a switch to the "high-speed side" takes place, i.e., the drive side of a possible gearbox interacting with the motor unit. The motor speed can, for example, be approximately 2000 revolutions per minute and thus significantly exceeds the angular velocity of the components driven by the motor unit, which are connected downstream of a motor-driven gearbox. The high speed of the motor shaft therefore enables much more precise and finer sensing.Even the smallest changes in the expected movement sequence, especially during the closing sequence, of an appliance door are automatically expressed in a changing speed of the motor unit, so that a corresponding change can be sensed very reliably and quickly and can be reacted to for the purpose of pinching and / or crushing protection.

[0019] The inventive design also proves particularly advantageous when the appliance door is driven as intended. Based on the sensor unit provided for detecting the motor speed, a motor control loop can be implemented that can compensate for nonlinearities in the motor load, such as those caused by the door kinematics, but also by other effects such as increasing friction due to wear and / or aging of the components involved.

[0020] As a result, the inventive design enables motor-side sensing and thus, in contrast to the prior art, does not allow sensing of the components driven by the motor unit. This enables much faster and more precise detection of any parameters that change the movement of the appliance door, providing significantly improved protection against pinching and / or crushing. The operational reliability of a household appliance according to the invention is thus increased. In particular, it is possible to react much more precisely and quickly to unwanted blocking positions, preferably by switching off the motor unit.

[0021] According to the invention, the motor unit has a motor shaft. This has at least a first shaft section, which is preferably connected to a transmission in a slip-free manner.

[0022] According to a preferred embodiment, it is provided that the motor shaft has the first shaft section at one end and a second shaft section at the other end, wherein the first shaft section is preferably connected to the transmission in a slip-free manner and wherein the second shaft section is operatively connected to the sensor unit.

[0023] The motor shaft is preferably designed as a one-piece, continuous motor shaft, with the motor shaft being operatively connected to a gear box on one side and to the sensor unit according to the invention on the other. For this purpose, the motor shaft is equipped with a first shaft section at one end and a second shaft section at the other end. The first shaft section is connected to the gear box, preferably without slippage, and the second shaft section is operatively connected to the sensor unit according to the invention. The motor unit and the cooperating gear box can preferably be designed as a one-piece drive unit.

[0024] As an alternative to a one-piece motor shaft, the motor unit provides a first motor shaft and a second motor shaft. In this case, the first motor shaft serves as the first shaft section, and the second motor shaft serves as the second shaft section.

[0025] According to a further embodiment, the motor shaft can also be operatively connected to the sensor unit via the (first) shaft section, which is preferably connected to the transmission without slippage. In this case, the sensor unit is not located on the side of the motor unit remote from the transmission, but rather between the transmission and the motor unit, i.e., it detects the rotational speed of the motor shaft between the transmission and the motor unit. Thus, no additional shaft section is required on the side of the motor unit remote from the transmission.

[0026] The decisive factor is therefore that the design allows for the speed applied to the motor shaft during normal operation, i.e., for determining the speed of the motor shaft or the angular velocity. Such speed measurement must take place directly on the motor side, i.e., on the drive side before the gearbox. This is done to ensure the highest possible speed is available as a basis for measurement, which, as already described, requires a very sensitive and therefore precise anti-jamming or anti-rotation device.

[0027] Anti-crushing protection is possible.

[0028] According to a further feature of the invention, a control device is provided which, when the appliance door is moved from an open position to the closed position - and / or from the closed position to an open position - detects the speed of the motor shaft with the sensor unit and outputs a signal corresponding to the speed as an actual value, which compares the actual value with a predeterminable target value with a comparison circuit and which, if the actual value deviates from the target value outside a predeterminable tolerance window, switches off the motor unit with the switch-off device.

[0029] The control device of the household appliance according to the invention has the sensor unit already explained above as well as a comparison circuit and a shutdown device.

[0030] The sensor unit detects the speed of the motor shaft when the appliance door is moved from an open position to the closed position and / or from the closed position to an open position. This detection is preferably continuous, but can also occur at suitable discrete intervals. Continuous detection is preferred, however, as it provides a higher level of safety.

[0031] The sensor unit transmits a signal corresponding to the motor shaft speed as an actual signal to the comparison circuit. For this purpose, the sensor unit and the comparison circuit are connected via communication technology.

[0032] The comparison circuit compares the actual values ​​transmitted from the sensor unit to the comparison circuit with predefined target values. This comparison makes it possible to determine whether the appliance door is being driven as intended by the motor unit or whether the motor shaft speed is within a speed range that is inadmissible for the appliance door to pivot as intended. If the actual values ​​deviate from the target values, i.e. if there is a discrepancy, this means that the appliance door is not moving as intended, i.e. is not being driven by the motor unit in the expected manner. This means that the appliance door is not moving as intended, i.e. is blocked.In this case, the shut-off device shuts down the appliance door by deactivating the motor unit. If the sensor unit detects a motor shaft speed that is not expected for the intended pivoting of the appliance door, the motor unit is immediately shut down for safety reasons. Consequently, any pivoting movement of the appliance door is also interrupted, thus providing effective protection against pinching and / or crushing.

[0033] In order to accommodate potentially varying environmental influences at the installation location of a dishwasher, the invention incorporates a predefined tolerance range when comparing actual and target values. Therefore, the motor unit is only shut down if an actual value deviates from a target value outside a predefined tolerance window. The size of the tolerance window is preferably adjustable, even retroactively, so that the response behavior of the shutdown device can be readjusted if necessary and adapted to any special features that may exist at the installation location of the dishwasher.

[0034] An automatic shutdown of the motor unit ensures that the movement of the appliance door stops if the determined, actual speed of the motor shaft of the motor unit deviates from the speed of the motor shaft of the motor unit to be expected during intended use. The design according to the invention is therefore not aimed at monitoring possible movement of the appliance door and possible relative movement of individual appliance door components, but rather at detecting the speed of the motor-side output shaft. During normal operation, the speed of the motor shaft of the motor unit does not change. Regardless of a possible open position of the appliance door, the motor unit always provides the same speed with regard to its motor shaft. A blockage of the appliance door therefore results in a braking effect on the motor unit, resulting in a reduction in the speed of the motor shaft.Based on such a deviation between the actual speed on the one hand and the expected target speed on the other, the blockage is detected. In the intended use case, it is irrelevant whether the blockage of the appliance door is caused, for example, by an uninserted dish basket or by a foreign object being wedged in the door gap, or by other causes. The detection of a blockage made possible by the inventive design is, in particular, independent of the weight of the appliance door and also independent of whether the appliance door is still in the open position or has already moved toward the closed position.Since the motor shaft is moved comparatively quickly in its intended use, at least in relation to the speed of movement of the slower, in particular significantly slower, appliance door and / or its components driven by the motor unit, a very sensitive and therefore precise detection is also achieved.

[0035] According to a further feature of the invention, the sensor unit comprises an optical sensor and / or a magnetic field sensor. Such sensors enable precise speed detection in a simple manner, are inexpensive to purchase, and enable reliable sensing even over extended periods, as they are low-wear.

[0036] According to a further feature of the invention, the sensor unit comprises an incremental encoder. This is coupled to the motor shaft, and during operation, its rotational movement is detected by a sensor. The incremental encoder can be designed, for example, as a perforated disk. This results in an overall robust yet reliable design of a sensor unit according to the invention. The incremental encoder, designed, for example, as a perforated disk, is mounted on the motor shaft of the motor unit in a rotationally secure manner. Undesired incorrect measurements and / or error tolerances are thus reliably prevented.

[0037] According to a further feature of the invention, the perforated disc is bell-shaped. Such a bell-shaped design advantageously enables assembly and disassembly exclusively in the axial direction of the motor shaft. This makes it easy to install the sensor unit according to the invention or a motor unit coupled thereto, which is advantageous given the limited installation space available.

[0038] According to a further feature of the invention, the perforated disc interacts with a light barrier. The light barrier serves as the actual sensor. When used as intended, the light barrier can detect a rotational movement of the motor shaft by alternately interrupting or allowing the light beam of the light barrier to pass through. An evaluation of the pulses thus generated allows real-time conclusions to be drawn about the current motor speed.

[0039] According to a further feature of the invention, the light barrier can be a forked light barrier. Depending on the design, this is used in particular in combination with a disc-shaped or bell-shaped perforated disc. However, the light barrier can also be a retro-reflective light barrier. This is used in particular in combination with a disc-shaped, particularly partially reflective, perforated disc. The advantage of a retro-reflective light barrier is that, unlike a forked light barrier, it does not surround the perforated disc, which simplifies assembly and disassembly.

[0040] According to a further feature of the invention, the incremental encoder is a multipole ring segment. In this case, the actual sensor is not a light barrier, but rather a sensor that interacts with the multipole ring segment, for example, a Hall sensor.

[0041] According to a further feature of the invention, the sensor unit comprises a circuit board carrying the actual sensor, for example, the light barrier or the Hall sensor. This circuit board can also incorporate evaluation electronics. In particular, the previously described comparison device and the shutdown device can be housed on the circuit board. Thus, when used as intended, the circuit board enables a direct comparison between the detected actual speed and a predeterminable target speed, so that the motor unit can also be shut down using the circuit board if the detected actual values ​​deviate too significantly from the predeterminable target values.

[0042] According to a further feature of the invention, the circuit board provides connection contacts for the contact lugs of the motor unit. This enables an electrical connection between the circuit board and the motor unit. Power can thus be supplied to both the circuit board and the motor unit via one or more central connection contacts of the circuit board. This results in an overall simple and compact design. In particular, no additional, i.e., separate, power cabling is required between the circuit board and the motor unit.

[0043] The connection contacts provided by the circuit board can be soldered to the contact lugs on the motor unit. However, it is preferred to design the connection contacts as plug-in contacts. The circuit board pre-equipped with a sensor can therefore be easily plugged onto the motor unit and then connected to a power supply. As a result, power is supplied to both the circuit board and the electrical components carried by it, on the one hand, and to the motor unit, on the other, via just one power connection in the form of a group connection. According to a further feature of the invention, it is provided that the sensor unit is arranged on the motor unit so that it can be mounted or dismounted in the axial direction of the motor shaft. According to this particularly preferred embodiment of the invention, it is provided that the sensor unit is designed to be pre-assembled and is suitable for mounting or dismounting.During disassembly, the sensor unit can only be moved toward or away from the motor unit in the axial direction of the motor shaft. A secure positioning of the sensor unit on the motor unit can be achieved simply by the contact tabs on the motor unit engaging the connection contacts of the circuit board, which are designed as plug contacts, in the final assembled state. Alternatively, additional fastening means can be provided for the secure positioning of the sensor unit on the motor unit, whereby these additional fastening means should also preferably be mounted or disassembled in the axial direction of the motor shaft.

[0044] The result of the inventive design is the particular advantage that crushing or pinching situations can be detected very sensitively, quickly, and reliably. In particular, it is possible to detect any crushing or pinching situations within milliseconds. A further advantage lies in the location of the rotary encoder and its design. The inventive design thus avoids having to attach a rotary encoder or pulse generator to the appliance door itself or to components of the door mechanism. Instead, the incremental rotary encoder provided according to the invention is located directly on the motor unit. This also requires very little installation space and reduces installation effort and costs. Furthermore, the proposed sensor unit can be used to create a control circuit for the motor unit that is optionally specifically tailored to the household appliance and is suitable for compensating for external influences.Such external influences can include, for example, widely varying total door weights, spring settings, and potentially increasing friction or wear in the entire door mechanism over its service life. The same applies to nonlinearities in the motor load caused by the door mechanism itself.

[0045] Further features and advantages of the invention will become apparent from the following description with reference to the figures.

[0046] Fig. 1 shows a purely schematic side view of a household appliance according to the invention; Fig. 2 shows a schematic perspective view of a section of the base area of ​​the household appliance according to Fig. 1 with a drive device;

[0047] Fig. 3a shows a purely schematic representation of a drive device and a sensor unit cooperating with its motor unit according to a first embodiment;

[0048] Fig. 3b shows a purely schematic representation of a drive device and a sensor unit cooperating with its motor unit according to a second embodiment;

[0049] Fig. 4 shows a schematic perspective view of a drive device with motor unit and adapted sensor unit in assembled position;

[0050] Fig. 5 shows a schematic representation of the drive device according to Fig. 4 in a partially disassembled position;

[0051] Fig. 6 shows a schematic representation of the drive device according to Fig. 4 in a partially disassembled position;

[0052] Fig. 7 shows a schematic representation of the drive device according to Fig. 4 in a partially disassembled position;

[0053] Fig. 8 shows a schematic perspective view of the drive device according to Fig. 4;

[0054] Fig. 9 shows a schematic perspective view of a drive device according to a second embodiment of the sensor unit;

[0055] Fig. 10 is a schematic perspective view of the drive device according to Fig. 9 from a different angle;

[0056] Fig. 11 shows a further schematic perspective view of the drive device according to Fig. 9;

[0057] Fig. 12 shows a schematic perspective view of a drive device according to a further embodiment of the sensor unit;

[0058] Fig. 13 shows a schematic perspective view of a drive device according to a further embodiment of the sensor unit;

[0059] Fig. 14 shows a further schematic perspective view of the drive device according to Fig. 13;

[0060] Fig. 15 is a schematic perspective view from the front showing the sensor unit according to an embodiment;

[0061] Fig. 16 shows a schematic perspective view of a section of the sensor unit according to Fig. 15;

[0062] Fig. 17 shows a further detailed view of the sensor unit according to Fig. 15 and

[0063] Fig. 18 shows a schematic exploded view of a drive device including a sensor unit.

[0064] Fig. 1 shows a purely schematic representation of a household appliance 1 according to the invention, which, without limiting its generality, can be designed, for example, as a dishwasher.

[0065] The household appliance has a housing 2 that accommodates an appliance container 3. The appliance container 3, in turn, provides a treatment chamber 4, which, for example, when configured as a dishwasher, serves to accommodate items to be cleaned during its intended use. The appliance container 3 has a loading opening 5 for access to the treatment chamber 4.

[0066] The household appliance further comprises an appliance door 6 mounted for rotation about a pivot axis, which serves to close the loading opening 5. The appliance door 6 can be moved from a closed position, closing the loading opening 5, to an open position, and vice versa. Fig. 1 shows the appliance door 6 in an open position, in which the loading opening is partially open. As can be seen from the detail view in Fig. 2, the appliance door 6 has a lever 10 arranged on it near the pivot axis. One such lever 10 is provided on each side of the appliance door.

[0067] A force transmission means 9 is arranged on one end of each lever 10. The force transmission means 9 is guided around a first deflection pulley serving as an intermediate member 11 and around a second deflection pulley 12, and is arranged on the other end on a spring element 8 fixed relative to the device container 3. This spring element 8, together with the force transmission means 9, forms a spring mechanism 7. A cable, a chain, a toothed belt, or the like can be provided as the force transmission means 9.

[0068] When the appliance door 6 is opened, the force transmission means 9 arranged on the levers 10 are subjected to tensile stress, which leads to tensioning of the spring element 8 arranged on the other end of the respective force transmission means 9. This provides weight compensation with respect to the appliance door 6, which in particular prevents the appliance door 6 from pivoting downwards in an uncontrolled manner.

[0069] The force stored in the spring elements 8 is released again when the appliance door 6 is moved back into the closed position, which enables simplified closing of the appliance door 6.

[0070] The household appliance, in particular the dishwasher, further comprises a drive device 13. This drive device 13 is operatively connected to the appliance door 6 and allows a motor-driven pivoting of the appliance door 6.

[0071] When the drive device 13 is in operation, it drives the intermediate member 11 via a coupling device 14, which interacts with the power transmission means 9. Motor-driven rotation of the intermediate member 11 thus leads to a force loading or unloading of the spring element 8, depending on the direction of rotation of the drive device 13.

[0072] As can be seen from the schematic representations in Fig. 3a and Fig. 3b, the drive device 13 has a motor unit 15 and a gear unit 16 interacting therewith. The motor unit 15 provides a motor shaft 17. According to the embodiment of Fig. 3a, this has a first shaft section 18 at one end and a second shaft section 19 at the other end. The first shaft section 18 is connected to the gear unit 16 in a slip-free manner. In the intended use, the gear unit 16 is thus driven by the motor unit 15 with the first shaft section 18 interposed.

[0073] The transmission 16 provides a transmission shaft 20 as the output shaft. This transmission shaft 20, in turn, interacts with the clutch device 14. On the output side of the clutch device 14, an output shaft 21 is provided, which interacts with the intermediate member 11.

[0074] As can also be seen from the illustration in Fig. 3a and Fig. 3b, a sensor unit 22 is provided. This serves to detect the rotational speed of the motor shaft 17, for which purpose the sensor unit 22, according to the embodiment of Fig. 3a, is operatively connected to the second shaft section 19 of the motor shaft 17, which operative connection is shown in Fig. 3a by the arrow 23. According to the embodiment of Fig. 3b, the sensor unit 22 detects the rotational speed of the motor shaft 17 at the shaft section arranged between the motor unit 15 and the gearbox 16, which shaft section is connected to the gearbox 16 without slip. The sensor unit 22 is therefore designed in both cases to detect the rotational speed of the motor shaft 17 of the motor unit 15.

[0075] The motor unit 15 of the drive device 13 is operatively connected to the appliance door 6 and makes it possible to move the appliance door 6 from an open position into a closed position closing the loading opening 5 - and / or from the closed position into an open position.

[0076] During a motor-driven pivoting movement of the appliance door 6, the speed of the motor shaft 17 of the motor unit 15 is detected by the sensor unit 22. If the actual speed of the motor shaft 17 detected by the sensor unit 22 deviates from a predeterminable target speed of the motor shaft 17, this can be interpreted as a blockage of the appliance door 6. Such a blockage of the appliance door 6 can occur in particular if there are foreign objects in the closing gap of the appliance door 6, for example limbs or parts thereof belonging to a user of the dishwasher. In order to implement pinching or crushing protection, the motor unit 15 is automatically switched off or stopped if a blockage is detected, i.e. the actual speed deviates from the target speed. The same applies if the door is pushed or accelerated during the motor-driven pivoting movement.

[0077] For this purpose, the household appliance has a control device which, with the sensor unit 22, detects the rotational speed of the motor shaft 17 when the appliance door 6 is moved from an open position to the closed position and / or from the closed position to an open position and outputs a signal corresponding to the rotational speed as the actual value. The control device also has a comparison circuit which compares the actual value supplied by the sensor unit 22 with a predeterminable target value. If a deviation is detected during this comparison, the motor unit 15 is immediately switched off, for which purpose the control device has a switch-off device.

[0078] The presettable target value is preferably stored in a memory of the comparison circuit. Furthermore, a presettable tolerance window can be stored in the memory of the comparison circuit, so that the motor unit 15 is not switched off when there is a mathematical discrepancy between the actual value and the target value, but only when the target value deviates from the actual value outside the presettable tolerance window. This allows wear and tear and / or special influences at the installation location of the dishwasher to be taken into account.

[0079] As a result, during a movement, such as a closing movement of the appliance door 6, a continuous comparison takes place between the actual speed of the motor shaft 17, as detected by the sensor, and the target speed of the motor shaft 17 expected according to a previously known movement profile. In the event of a deviation, the motor unit 15 is immediately switched off, which leads to an immediate stop of movement of the appliance door 6. In order to adapt the response behavior of the switch-off device to special conditions that may prevail at the installation location of the dishwasher, the tolerance window for the comparison between the actual value and the target value is provided. This tolerance window can of course also be set to zero, in which case the smallest difference between the actual value and the target value is sufficient to switch off the motor unit 15.Figures 4 to 8 show, in different views, a first embodiment of a drive device 13 which is designed in accordance with the invention and has a sensor unit 22 for detecting the rotational speed.

[0080] The drive device 13 has, as already described, a motor unit 15 and a gear unit 16 coupled thereto. On the output side of the gear unit 16, a gear shaft 20 is provided, which interacts with the coupling device 14 in a manner also already described.

[0081] In the axial direction of the motor shaft 17 provided by the motor unit 15, the second shaft section 19 of the motor shaft 17 is provided opposite the gear 16. This factual connection can be seen, for example, from a comparison of Figures 5 and 6.

[0082] In the final assembled state, the second shaft section 19 of the motor shaft 17 interacts with the sensor unit 22.

[0083] The sensor unit 22 has a housing 24 that houses the actual sensor of the sensor unit 22. The housing 24 consists of a base body 25 and a cover 26. In the final assembled state, the base body 25 is secured in position on the drive device 13, and the cover 26 rests on the base body 25.

[0084] The sensor unit 22 further comprises a circuit board 29, which is arranged on the base body 25 of the housing 24. This circuit board 29 provides electronic components as well as power connection contacts 32, as can be seen, for example, in Figures 6 and 7.

[0085] In the illustrated embodiment according to Figures 4 to 8, a forked light barrier 31 is used as the actual sensor of the sensor unit 22. This forked light barrier 31 interacts with a perforated disk 30, which is attached to the end of the second shaft section 19 of the motor shaft. As a result of the interaction of the perforated disk 30 and the forked light barrier 31, the motor shaft speed can be detected when the motor shaft 17 is rotated as intended. As can be seen in particular from the illustration in Figure 7, the printed circuit board 29 can be guided over the motor shaft in the axial direction of the motor shaft 17 for arrangement on the base body 25. For this purpose, the printed circuit board 29 has an opening 33, through which the second shaft section 19 of the motor shaft 17 is guided in the finally assembled state.

[0086] The printed circuit board 29 also has two openings 34 and 35 through which the contact lugs 27 and 28 of the motor unit 15 are passed in the final assembled state.

[0087] The contact lugs 27 and 28 of the motor unit 15 are, in the final assembled state, electrically connected to the power connection contacts 32 of the printed circuit board 29, so that when the power connection contacts 32 are connected to a power supply as intended, not only the printed circuit board 29 and the electronic and / or electrical components carried thereon, but also the motor unit 15 are supplied with electrical energy.

[0088] According to an alternative embodiment of the invention, which is shown in Figures 9, 10 and 11, the perforated disk 30 is bell-shaped and the forked light barrier 31, in contrast to the first embodiment according to Figures 4 to 8, is arranged on the circuit board 29 rotated by 90°. This embodiment provides the advantage of simplified assembly, since the circuit board 29 and the perforated disk 30 can be pushed onto the motor shaft 17 independently of one another, exclusively in a direction axial to the motor shaft 17. This simplifies both assembly and, in the event of repair, disassembly, since pre-assembly of the circuit board 29 and the perforated disk 30 is eliminated.

[0089] The embodiment according to Fig. 12 also offers the advantage of simple assembly and disassembly. In accordance with the exemplary embodiment according to Figures 4 to 8, a disk-shaped perforated disk 30 is also used according to this embodiment, however not in combination with a forked light barrier 31, but in combination with a reflected light barrier 38. The use of a reflected light barrier 38 also makes pre-assembly of the partially reflecting perforated disk 30 and circuit board 29 superfluous, and this while at the same time making it possible to arrange both the circuit board 29 and the perforated disk 30 in the exclusively axial direction of the motor shaft 17 on the motor unit 15.

[0090] Figures 13 and 14 show a further embodiment. According to this embodiment, instead of an optical sensor 31 or 38, a magnetic sensor is used, namely a Hall sensor 40. In the intended use, this interacts with a multipole ring magnet 39 which is plugged onto the second shaft section 19 of the motor shaft 17.

[0091] Soldering can be provided for electrically connecting the contact lugs 27 and 28 to the circuit board 29. However, it is preferred to provide connection contacts in the form of plug contacts 36 and 37, as shown in Figures 15, 16, and 17. Plug contacts 36 and 37 are then provided, which, on the circuit board side, connect to the openings 34 and 35 formed in the circuit board 29 in the axial direction of the motor shaft 17. During assembly, the contact lugs 27 and 28 of the motor unit 15 extend through the corresponding openings 34 and 35 and are received by the plug contacts 36 and 37 in a precisely positioned and securely positioned manner. This creates an electrical contact between the circuit board 29, on the one hand, and the motor unit 15, on the other hand, which is easy to assemble and, in the event of repair, also easy to disassemble. In addition, no additional position securing of the circuit board 29 on the motor unit 15 is required.Rather, it is securely clamped to the motor unit 15 via the intermediary of the plug contacts 36 and 37.

[0092] Finally, Fig. 18 shows an exploded view of the inventive design. Accordingly, a drive device 13 and a sensor unit 22 are provided. The drive device 13 provides the motor unit 15, which in turn has a shaft 17 with a first shaft section 18 and a second shaft section 19. In the final assembled state, the second shaft section 19 interacts with the sensor unit 22.

[0093] The sensor unit 22 has a rotary pulse generator arranged on the second shaft section 19, for example a perforated disk 30. This rotary pulse generator interacts with the actual sensor, for example in the form of a forked light barrier 31.

[0094] The forked light barrier 31 is mounted on a circuit board 29, which, in the final assembled state, is electrically connected to the motor unit 15. For this purpose, the circuit board 29 has plug contacts 36 and 37, into which corresponding contact tabs 27 and 28 of the motor unit 15 engage in the final assembled state. Both the circuit board 29 and the motor unit 15 can be supplied with electrical power via common power connection contacts 32.

[0095] For arranging the sensor unit 22 on the drive device 13, a base body 25 is provided which, in the final assembled state, interacts with a cover 26, wherein the base body 25 and the cover 26 together form a housing 24 which, in the final assembled state, accommodates the printed circuit board 29 and the rotary pulse encoder arranged on the second shaft section 19.

[0096] Reference symbol

[0097] 1 household appliance 20 18 first wave section

[0098] 2 Housing 19 second shaft section

[0099] 3 Equipment container 20 Gear shaft 4 Treatment chamber 21 Output shaft

[0100] 5 Loading opening 22 Sensor unit

[0101] 6 Appliance door 25 23 Arrow (active connection)

[0102] 7 Spring mechanism 24 Housing

[0103] 8 Spring element 25 Base body 9 Power transmission element 26 Cover

[0104] 10 Lever 27 Contact flag

[0105] 11 Intermediate link so 28 Contact lug

[0106] 12 pulley 29 circuit board

[0107] 13 Drive device 30 Perforated disc 14 Coupling device 31 Fork light barrier (sensor)

[0108] 15 Motor unit 32 Power connection contact

[0109] 16 Gearbox 35 33 Opening

[0110] 17 Motor shaft section 34 Breakthrough 35 Breakthrough

[0111] 36 plug contact

[0112] 37 plug contact

[0113] 38 Reflex light barrier (sensor) 39 Multipole ring magnet

[0114] 40 Hall sensor

Claims

Patent claims 1. Household appliance, in particular a dishwasher, with an appliance container (3) providing a treatment chamber (4), which has a loading opening (5) for accessing the treatment chamber (4), which can be closed by means of an appliance door (6) mounted so as to be rotatable about a pivot axis, and with a motor unit (15) which is operatively connected to the appliance door (6) and by means of which the appliance door (6) can be moved from an open position into a closed position closing the loading opening (5) and / or from the closed position into an open position, characterized by a sensor unit (22) which is designed to detect the rotational speed of a motor shaft (17) of the motor unit (15).

2. Household appliance according to claim 1, characterized in that the motor shaft (17) has a first shaft section (18) on one end, which is connected to a gear (16) in a slip-free manner, and wherein the motor shaft (17) preferably has a second shaft section (19) on the other end, and wherein the first shaft section (18) or second shaft section (19) is in operative connection with the sensor unit (22).

3. Household appliance according to claim 1 or 2, characterized by a control device which, with the sensor unit (22), detects the speed of the motor shaft (17) when the appliance door (6) is moved from an open position to the closed position and / or from the closed position to an open position and outputs a signal corresponding to the speed as an actual value, which compares the actual value with a predeterminable target value with a comparison circuit and which, if the actual value deviates from the target value outside a predeterminable tolerance window, switches off the motor unit (15) with a switch-off device.

4. Household appliance according to one of the preceding claims, characterized in that the sensor unit (22) comprises an optical sensor and / or a magnetic field sensor.

5. Household appliance according to one of the preceding claims, characterized characterized in that the sensor unit (22) has an incremental encoder.

6. Household appliance according to claim 5, characterized in that the incremental encoder is a perforated disc (30) arranged on the motor shaft (17).

7. Household appliance according to claim 6, characterized in that the perforated disc (30) is bell-shaped and / or disc-shaped.

8. Household appliance according to claim 6 or 7, characterized in that the perforated disc (30) cooperates with a light barrier.

9. Household appliance according to claim 8, characterized in that the light barrier is a forked light barrier (31) or a reflex light barrier (38).

10. Household appliance according to claim 5, characterized in that the incremental encoder is a multipole ring magnet arranged on the motor shaft (17).

11. Household appliance according to one of the preceding claims, characterized in that the sensor unit (22) has a printed circuit board (29) which carries the sensor (31, 38, 40).

12. Household appliance according to claim 11, characterized in that the printed circuit board (29) provides connection contacts for contact lugs (27, 28) of the motor unit (15).

13. Household appliance according to claim 12, characterized in that the connection contacts are plug contacts (36, 37) or are electrically connected to the contact lugs (27, 28) of the motor unit (15) by soldering.

14. Household appliance according to one of the preceding claims 11 to 13, characterized in that the printed circuit board (29) has power connection contacts (32) for supplying power to both the sensor (31, 38, 40) and the motor unit (15).

15. Household appliance according to one of the preceding claims, characterized in that the sensor unit (22) is arranged on the motor unit (15) in such a way that it can be mounted and / or dismounted in the axial direction of the motor shaft (17).

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