DE102019135247A1 - ACTUATOR FOR ELECTRICAL HOUSEHOLD APPLIANCE - Google Patents

Abstract

Actuator (20) for an electrical household appliance, comprising: at least one fixed element (21, 22), at least one movable element (23) that is configured in such a way that it is located between at least two different positions relative to the fixed element (21, 22) is movable, a shape memory alloy member (24) operatively engaged with and extending therefrom in connection with the movable member (23) in connection with the movable member (23), the shape memory alloy member (24) being configured to a Receive activation signal and in response change its dimension to move the movable element (23) relative to the fixed element (21, 22). The actuator further comprises a modulation circuit (21a) to which the shape memory alloy element (24) is electrically connected. The modulation circuit (21a) comprises a plurality of electrical connections (25a, 25b) through which the modulation circuit (21a) can be connected to a control unit of the electrical household appliance. The modulation circuit (21a) is configured to convert a current signal from the control unit into an activation signal suitable for activating the shape memory alloy element (24) and to set a position of the movable element (23) based on a duration of the current signal .

Description

Aspects of the present disclosure relate to an actuator for an electrical household appliance, and in particular to an actuator which comprises: at least one fixed element, at least one movable element configured to be movable between at least two different positions relative to the fixed element is a shape memory alloy element that is operatively engaged with and extends therefrom in connection with the movable element, the shape memory alloy element configured to receive an activation signal and, in response, to change its dimension to relative the movable element to move to the fixed element.

The use of shape memory alloy (SMA) based actuators in household electrical appliances may involve the need to design the control units of the devices so that the control units are capable of outputting current signals that can be accepted by the actuators. In this regard, a control unit designed to work with solenoid actuators may not work correctly with an SMA-based actuator.

Accordingly, there is a need for an SMA-based actuator that can be configured to work with control units of current household electrical appliances.

The above and other requirements are met by an aspect of the present disclosure, which in one aspect indicates that the actuator further includes a modulation circuit to which the shape memory alloy element is electrically connected, the modulation circuit having a plurality of electrical connections through which the modulation circuit is connectable to a control unit of the electrical household appliance, the modulation circuit being configured to convert a current signal from the control unit into an activation signal, which is suitable for activating the shape memory alloy element, and to position the movable element based on a duration of the current signal put.

The modulation circuit can advantageously also be configured to condition the activation signal in such a way that the activation signal is tolerated by the shape memory alloy element. For example, the modulation circuit may modulate the activation signal to cause the shape memory alloy element to change its length to reach a desired position of the movable element and then maintain its length when the desired position has been reached while at the same time feeding the shape memory alloy element electrical current is controlled or limited to prevent the shape memory alloy element from overheating or being subjected to strong electrical cycles that can accelerate the aging of the SMA and cause premature failure.

In one aspect, the actuator may further include sensing means located on board the modulation circuit and configured to provide a position signal indicative of a position of the movable element. The modulation circuit may be configured to control the shape memory alloy element based on the position signal. The modulation circuit need only have two of the electrical connections. According to one aspect, the sensing means may comprise a light transmitter and a light receiver arranged in front of one another, the movable element having a coupling profile which is inserted between the light transmitter and the light receiver and configured to, based on the position of the movable element Optically couple the light receiver with the light transmitter or optically decouple the light receiver from the light transmitter. The coupling profile can be designed to ensure a smooth transition between a state in which the light receiver is optically coupled to the light transmitter and a state in which the light receiver is optically decoupled from the light transmitter.

Another aspect of the present disclosure provides a dispenser for dispensing a detergent and a dishwashing detergent in a dishwasher, the dispenser comprising: a receptacle used to receive a quantity of a detergent; a movable cover which is assigned to the receptacle and which can be displaced from an open position to a closed position in which it opens and closes the receptacle in each case; an automatically controlled closure element capable of adopting a deactivated configuration in which the closure element is configured to lock the lid in the closed position and an activated configuration in which the closure element releases the lid to allow that it changes from the closed position to the open position; and a metering valve configured to dispense the detergent; wherein the dispenser comprises an SMA-based actuator, wherein the movable element of the actuator moves to a first active position in which the movable element controls the closing element to transition from the deactivated configuration to the activated configuration and to a second active position in which the movable element controls the metering valve for dispensing the detergent, is movable.

In conventional dispensers, where the actuator is configured to move the movable member only to an active position, a drive mechanism capable of switching between a configuration in which the movable member activates door opening and a configuration is required , in which the movable element activates the metering valve ("mechanical reset"), as in the EP 1 740 082 B1 or the EP 1 909 632 B1 described. In a dispenser provided with an SMA-based actuator according to the invention, two or more active positions for the movable element can be inherently provided by the property of the actuator itself ("electronic reset"), and therefore no switching drive mechanism is required.

Yet another aspect of the present disclosure provides an air manifold for a refrigerator that includes: an air duct and an obturator that is configured to move between different positions in which the air duct is closed, partially open, and fully open, respectively , wherein the air distributor is characterized in that it has an actuator according to the invention, the movable element of the actuator being operatively connected to the obturator in order to control the position of the obturator.

Another aspect provides a method of controlling a linear actuator for a household electrical appliance, the linear actuator being at least one fixed member and at least one movable member configured to be relative to at least two different positions in response to an activation signal from a control circuit to be moved to the fixed member, the method comprising the steps of: providing a position signal indicative of a position of the movable member, and controlling the movable member based on the position signal, including controlling the movable member, a characteristic of the activation signal change based on the position signal.

Another aspect provides a method of controlling a linear actuator for a domestic electrical appliance, the linear actuator having at least one fixed element and at least one movable element configured to be relative to at least two different positions in response to an activation signal from a control circuit the fixed element, the method comprising the steps of: providing a time signal, and changing a characteristic of the activation signal based on the time signal.

Yet another aspect provides a method of controlling a linear actuator for a household electrical appliance, the linear actuator having at least one fixed member and at least one movable member configured to be relative to at least two different positions in response to an activation signal from a control circuit to be moved to the fixed member, the method comprising the steps of: providing a position signal indicative of a position of the movable member and controlling the movable member based on the position signal according to a conditional rule; the method further comprising: providing a time signal, wherein controlling the movable element comprises changing the conditional rule based on the time signal.

Other aspects indicate combinations of two or more of the control methods mentioned above. It should be noted that the above-mentioned methods can be applied generally to linear actuators, such as the above-mentioned SMA-based actuators, solenoid actuators, wax actuators, etc.

• 1a und 1b sind Draufsichten, jeweils von oben und von unten, einer Spendervorrichtung, die einen Aktuator gemäß der vorliegenden Offenbarung enthält;
• 2a und 2b sind Ansichten in unterschiedlichen Ebenen der Spendervorrichtung der 1a und 1b in einer ersten Betriebsposition;
• 3a und 3b sind Ansichten in unterschiedlichen Ebenen der Spendervorrichtung der 1a und 1b in einer zweiten Betriebsposition;
• 4a und 4b sind Ansichten in unterschiedlichen Ebenen der Spendervorrichtung der 1a und 1b in einer dritten Betriebsposition;
• 5a und 5b sind Ansichten in unterschiedlichen Ebenen der Spendervorrichtung der 1a und 1b in einer vierten Betriebsposition;
• 6a und 6b sind Ansichten in unterschiedlichen Ebenen der Spendervorrichtung der 1a und 1b in einer fünften Betriebsposition;
• 7 ist eine Explosionsansicht des Aktuators der Spendervorrichtung der 1a und 1b;
• 8 ist ein Zeitdiagramm, das das Betriebsverfahren des Aktuators von 7 zeigt;
• 9 ist ein Diagramm, das Spannung und durchschnittliche Aktuatorleistung gegen die Zeit während des Betriebs des Aktuators von 7 zeigt;
• 10 zeigt einen Vergleich zwischen dem Tastzyklus eines Stromsignals, das von einer Steuereinheit des elektrischen Haushaltsgeräts einem konventionellen Solenoidaktuator geliefert wird (oberes Diagramm) und dem Tastzyklus eines Stromsignals, das von einer Steuereinheit des elektrischen Haushaltsgeräts dem Aktuator von 7 geliefert wird (unteres Diagramm);
• 11a und 11b zeigen jeweils ein Schaltungslayout und ein Blockdiagramm einer ersten beispielhaften Modulationsschaltung für den Aktuator von 7;
• 11c und 11d zeigen jeweils ein Schaltungslayout und ein Blockdiagramm einer zweiten beispielhaften Modulationsschaltung für den Aktuator von 7;
• 12a bis 12d zeigen alternative Wellenverläufe für das von der Modulationsschaltung gelieferte Aktivierungssignal;
• 13a und 13b sind jeweils eine Perspektivansicht und einer Draufsicht einer weiteren Ausführung des Aktuators der Spendervorrichtung; und
• 14a und 14b sind jeweils eine Perspektivansicht und eine Draufsicht einer noch weiteren Ausführung des Aktuators der Spendevorrichtung.

Aspects of the present disclosure are described in the following detailed description, given by way of non-limiting example only, with reference to the accompanying drawings, wherein

• 1a and 1b 13 are top and bottom views, respectively, of a dispensing device that includes an actuator according to the present disclosure;
• 2a and 2 B are views in different levels of the dispensing device of the 1a and 1b in a first operating position;
• 3a and 3b are views in different levels of the dispensing device of the 1a and 1b in a second operating position;
• 4a and 4b are views in different levels of the dispensing device of the 1a and 1b in a third operating position;
• 5a and 5b are views in different levels of the dispensing device of the 1a and 1b in a fourth operating position;
• 6a and 6b are views in different levels of the dispensing device of the 1a and 1b in a fifth operating position;
• 7 12 is an exploded view of the actuator of the dispensing device of FIG 1a and 1b ;
• 8th FIG. 10 is a timing diagram illustrating the operating method of the actuator of FIG 7 shows;
• 9 is a graph showing voltage and average actuator power versus time during the operation of the actuator 7 shows;
• 10th shows a comparison between the duty cycle of a current signal, which is supplied from a control unit of the household electrical appliance to a conventional solenoid actuator (upper diagram) and the duty cycle of a current signal, which is supplied from a control unit of the household electrical appliance to the actuator of 7 is delivered (lower diagram);
• 11a and 11b each show a circuit layout and a block diagram of a first exemplary modulation circuit for the actuator of FIG 7 ;
• 11c and 11d each show a circuit layout and a block diagram of a second exemplary modulation circuit for the actuator of FIG 7 ;
• 12a to 12d show alternative waveforms for the activation signal provided by the modulation circuit;
• 13a and 13b are each a perspective view and a plan view of another embodiment of the actuator of the dispensing device; and
• 14a and 14b are each a perspective view and a plan view of yet another embodiment of the actuator of the dispensing device.

In the drawings, the reference number denotes 1 the entirety of a dispensing device for dispensing a detergent and a detergent. However, the invention is not limited to this specific application and can also be applied to other household electrical appliances.

As is known per se, such a dispensing device is used 11 to be attached to an inner wall of a door that closes a washing chamber of a dishwasher.

The dispenser 1 contains a body 2nd , which is made of molded plastic, for example, and is used to be connected in a manner known per se and not shown) to the door of the dishwasher on the side which, during operation, points towards the washing chamber of this dishwasher.

The body 2nd contains an in-depth picture 3rd (in the 2 B to 6b visible), essentially in the shape of a bowl). The recording 3rd is used to hold an amount of detergent, such as a powder detergent or a liquid detergent or a solid detergent in the form of a "soap bar" or a tablet.

The device 1 contains a movable lid 5 that of the recording 3rd is assigned and with the body 2nd connected is. The movable lid 5 is shiftable in a way that's on the body 2nd between a closed position ( 1a) and an open position (not shown) is limited where he can record 3rd each tightly closes and opens. In the example shown in the drawings is the lid 5 can be moved in the direction indicated by the arrow y. However, the invention is not limited to this type of movement, and includes, for example, designs in which the lid rotates around a fixed axis, as well as designs in which the lid follows a more complex path, such as a path that has a sliding component and has a tilting component.

An elastic return element (not shown) is conventional for the lid 5 assigned, the restoring element tending to shift the latter towards the open position. This restoring element can be a torsion spring, for example.

If the movable lid 5 is in the closed position ( 1 ), a locking arrangement holds it in this position against the action of the return spring 8th that would tend to bring him back to the open position. This locking arrangement conventionally comprises an elastically preloaded locking element (not shown) which is attached to the cover 5 is arranged, as well as an automatically controlled closing element (not shown), which on the body 2nd is arranged.

The locking element is with a manually operated opening element 15 like one on the lid 5 arranged button, integrally formed or firmly connected. The opening element 15 is conventionally operable to disengage the locking member from the closure member when the closure member is in a deactivated configuration to allow the lid 5 passes from the closed position to the open position under the action of a return member such as a spring (not shown).

In the example shown in the drawings, the closing element can be designed as a pivot lever, that of the receptacle 3rd for the detergent is adjacent. The pivot axis of the closing element is through a shaft 13 of the closing element defines and extends essentially orthogonally to the body 2nd the dispenser. A lower one End of wave 13 is in the 1a, b to 6a, b , visible. However, the invention is not limited to this type of movement for the closing element.

The lower end of the wave 13 is with a fork-shaped drive element 14 firmly connected through which the shaft 13 of the closing element with an electrically actuated actuator 20 operationally connected, which is described below. Because of this connection, the closing element is conventionally switchable and movable between a deactivated configuration in which the closing element can be gripped by the locking element of the cover when it is in the closed position, and an activated configuration in which the closing element releases the locking element of the cover to allow the lid 5 , under the action of the associated return spring 8th , from the closed position to the open position.

The body 2nd the dispensing device further includes one in the body 2nd trained tank 17th for detergent. The position of the detergent during the dispenser is in the 2 B to 6b indicated with a cross-hatched area. The Tank 17th is through a first opening 18a with a dosing chamber 18th fluidly connected. In the dosing chamber 18th is a metering valve 19th arranged. The dosing valve 19th contains a fixed valve body 19a and a slidable obturator 19b with a fastener 19c is firmly connected. Through the connecting element 19c can the obturator 19d through the actuator 20 being controlled. The dosing chamber 18th is with an outlet pipe 19e through a second opening 18b connected to the valve body 19a before the first opening 18a is trained. The outlet pipe 19e is conventionally connected to an outlet (not shown) through which the detergent can be dispensed into the washing chamber of the dishwasher. The obturator 19d is configured to alternatively open the first opening during its sliding movement 18a or the second opening 18b the dosing chamber 18th to close.

As especially in 7 shown, contains the actuator 20 at least one solid element. In the example of 7 these are two fixed elements, labeled with 21 and 22 . The first solid element 21 is a printed circuit board that is so called in the following description for simplicity. The printed circuit board carries a modulation circuit 21a , which is discussed below. The second fixed chamber 22 is a cover that attaches to the printed circuit board 21 and is so called in the following description for the sake of simplicity. According to other embodiments, there may be other fixed elements, such as a fixed main body to which the printed circuit board is attached.

The actuator 20 further includes at least one moveable element configured to be between at least two different positions relative to the fixed elements 21 and 22 is mobile. In the example of 7 this is a moving element 23 , which is configured as a slider (and is hereinafter called for simplicity), which is configured to move between at least two different positions relative to the fixed elements 21 and 22 is translationally movable. The slider 23 includes a first led projection 23a and a second led ledge 23b , each in a first guide slot 21a and a second guide slot 21b are included, which is the printed circuit board 21 push through. The first guided section 23a includes a connecting pin 23a ' which is inserted in a hole in the one with the obturator 19b of the metering valve 16 connected connecting element 19c is trained. In this way the slider is 23 with the obturator 19b of the metering valve 19th operationally connected.

The slider 23 further includes a drive section 23b that with the fork-shaped drive element 14 that is coupled to the shaft 13 of the closing element of the locking system of the cover 15 is connected. In this way the slider is 23 with the locking element of the locking system cover 5 operationally connected. According to other embodiments, other drive connections can also be provided between the slide and the locking element of the cover.

The slider 23 also includes a coupling profile 23e , whose function is described below.

The actuator 20 also includes a shape memory alloy (SMA) element 24th that with the printed circuit board 21 is operationally engaged and from there in connection with the slide 23 extends. In the example shown in the drawings, the shape memory alloy element is 21 configured as an SMA wire, and is referred to below for the sake of simplicity. In particular, the SMA wire 24th a U-shaped wire, the opposite ends of which 24a and 24b with the modulation circuit 21a the printed circuit board 21 are mechanically and electrically connected, and its intermediate bend 24c at their ends 24a and 24b of the SMA wire 24th opposite end with one in the slider 23 trained groove 23d is coupled. According to other embodiments, the SMA wire can be laid in other ways, such as, for example, a V-shaped shape or a straight shape.

Through the modulation circuit 21a the printed circuit board 21 is the SMA wire 24th configured to receive a current signal from a control unit (not shown) of the electrical household appliance and, in response, change its dimension to the slider 23 relative to the fixed elements 21 , 22 to move. Due to the operational connection between the slide 23 and the wave 13 of the lid locking system on the one hand, and between the slide 23 and the obturator 19b of the metering valve 19th on the other hand, is the actuator 20 able to open the lid 5 and the metering valve 19th to control. The one from the SMA wire 24th a restoring element acts 24f like a spring against its first end 23g with the slider 23 is connected, and its second end 23 " in 21c with the printed circuit board 21 connected is.

The modulation circuit 21a the printed circuit board 21 is configured so that it can be connected to the control unit of the electrical household appliance by electrical connections. In the example shown in the drawings, these are two electrical connections, with 25a and 25b designated. Conventionally, an electrical connector can be used with these electrical connections 26 for example, a plug of the RAST type, for electrical connection to the control unit of the electrical household appliance.

The modulation circuit 21a the printed circuit board 21 is configured to convert the current signal from the control unit into an activation signal that is used to activate the SMA wire 24th suitable is.

Sensing means on the printed circuit board are preferred 21 arranged and configured to provide a position signal representing a position of the slider 23 indicates. In the example shown in the drawings, the sensing means are configured as optical sensing means. According to other embodiments, the sensing means can, for example, also be magnetic sensing means, such as Hall effect sensors, or mechanical sensing means, such as microswitches.

The modulation circuit is preferred 21a the printed circuit board 21 configured to the SMA wire 24th based on the position signal supplied by the sensing means. According to alternative embodiments, in which the control unit of the electrical household appliance is configured to use the SMA wire 24th to control based on the position signal supplied by the sensing means is another connector on the printed circuit board 21 provided for a position signal connection between the printed circuit board 21 and to provide the control unit of the electrical household appliance.

In the example shown in the drawings, the sensing means comprise a light transmitter 26 , such as a light emitting diode, and a light receiver 27 , such as a photodetector, arranged in front of each other. The coupling profile 29e the slide 23 is between the light transmitter 26 and the light receiver 27 inserted and is configured to the light receiver 27 with the light transmitter 26 optically to couple or the light receiver 27 from the light transmitter 26 , based on the position of the slider 27 to optically decouple.

Im in the 7 and 8th The example shown includes the coupling profile 29e a first signal generation front 23ea, which acts as the end edge of the coupling profile 23e is formed, and a second signal generation front 23eb, which acts as the front edge of one in the coupling profile 23e trained slot is formed. The signal generation fronts are along the direction of movement of the slide 23 , denoted in the drawings by an arrow x, arranged in succession.

The operation of the dispenser discussed above will now be described.

The 2a and 2 B show the donor 1 in a start position which generally corresponds to a situation in which a user has set some controls of the dishwasher to start a washing program and has closed the door of the dishwasher after taking the picture 3rd filled with a detergent and the dispenser lid 5 has closed. The actuator 20 is in its deactivated configuration, with the slider 23 in its starting position. The first opening 18a the dosing chamber 18th is through the obturator 19b of the metering valve 19th closed during the second opening 18b is open. The lid 5 is closed.

The 3a and 3b show the donor 1 after the actuator 20 has been activated to the slider 23 to move a first stroke (to the left in the drawings). This first stroke is dimensioned such that it corresponds to the state of the first opening 18a and the second opening 18b the dosing chamber 18th does not change. Therefore, the first opening is after the first stroke 18a the dosing chamber 18th through the obturator 19b of the metering valve 19th still closed, and is the second opening 18b still open. On the other hand, the movement of the slide has 18th the fork-shaped drive element 18th and the wave 13 driven to rotate. Hence the wave 13 assigned closing element moves and has the locking element of the lid 5 loosened, and consequently the cover has come off 5 under the action of the return spring 8th moved to its open position.

The 4a and 4b show the donor 1 after the actuator 20 has been deactivated. The slider 23 has therefore returned to its starting position. The first opening 18a the dosing chamber 18th is through the obturator 19b of the metering valve 19th still closed, and the second opening 18b is still open. On the other hand, the movement of the slide has the fork-shaped drive element 14 and the wave 13 the backward rotation to their starting positions. The lid 5 is open and remains in this position.

The 5a and 5b show the donor 1 when the actuator 20 has been reactivated to the slider 23 to move a second stroke (to the left in the drawings) that is longer than the first stroke. Of course, the second stroke has no effect on the lid, since the lid is already in its open position. On the other hand, after the second stroke is the obturator 19b of the metering valve 19th in the first opening 18a the dosing chamber 18th been moved away in such a way that the opening 18a is opened, and to the second opening 18b to such a way that the second opening 18b is closed. Hence a lot of detergent from the tank 17th to the dosing chamber 18th flowed.

The 6a and 6b show the donor 1 after the actuator 20 has been deactivated again. The movement of the slider has the obturator 19b of the metering valve 19th driven back to their starting positions. The first opening 18a the dosing chamber 18th has therefore returned to its closed position, and the second opening 18b has returned to her open position. On the other hand is the lid 5 open and remains in this position. As a result, the amount of detergent in the dosing chamber 18th from the dosing chamber 18th to the outlet pipe 19e flowed, and therefore into the dishwasher's rinsing chamber.

The steps of the 5a-5b and 6a-6b are repeated during dispensing depending on the total amount of detergent required to be released during the wash cycle.

8th shows a timing diagram of the donor operation. It should be noted that the operation of the actuator 20 is coordinated with a timer circuit, which is preferably in the modulation circuit 21 the printed circuit board 21 is implemented. However, according to an alternative embodiment, the timer circuit could also be implemented in the control unit of the electrical household appliance. The set point position for the actuators (the distance covered by the moving part of the actuator) is determined as a function of the duration of the current signal supplied by the control unit of the electrical household appliance. In 8th the bars indicated by "signal time <Tt" and signal time> Tt "represent the duration of the current signals which are supplied by the control unit of the electrical household appliance. A current signal of short duration, ie shorter than a threshold time Tt , causes the actuator 20 the movable element 23 moved from a starting position to a first position at most. A current signal of longer duration, ie longer than the threshold time Tt , causes the actuator 20 the movable element 23 moved from the start position to a second position farther from the start position than the first position. More specifically, the current signal required to reach the first position has a duration that is shorter in time than the threshold time Tt and longer than the time it takes for the moving part of the actuator to reach the state in which the first signal generation front 23aA completely blocks the light beam directed to the optical receiver for the first time, which prevents the receiver from receiving the light beam (hereinafter referred to as the "masking time", T1 , designated). This masking time can vary with each activation or for each actuator depending on boundary conditions in a tolerance of components, ambient temperature of the system and uncontrollable mechanical causes.

The inserts A, B and C in 8th show the schematic cross section of the actuator 8th in an area where the light transmitter 26 and the light receiver 27 are arranged. In particular, the insert A corresponds to a state in which the slide 23 starts moving when activated, from the position of the 2a to 2 B or from the position of the 4a-4b . In these positions, the one from the light transmitter 26 generated light beam from the light receiver 27 receive.

If the slider 23 which differs from the position of the 2a-b moved the position of the 3a-3b reached and caused the lid to move 5 opens (at the concealment time T1 ), ie when the first stroke is completed (in 8th also as a hub 1 designated), reaches the first signal generation front 23eA the slide 23 the position of the insert B of 8th , ie it interrupts the light beam and decouples the light receiver 27 from the light transmitter 26 . This solves that with the light transmitter 26 and the light receiver 27 connected sensing circuit to output a position signal indicating that the first stroke has been completed.

After the position of the 3-3b and insert B has been reached, the slide remains 23 in this position until the predetermined threshold time Tt is reached. The length of time the slider is in the position of the 3a-3b and the Insert B is held in 8th as a "dwelling position 1 ". As stated above, is the time when the first generation front 23eA the light from the emitter is completely blocked due to different component tolerances and different operating conditions of the same dispenser. The effect of the configuration described above is to get a defined feedback system ON position of the slide that is specific to the actuator of the dispenser without interacting with the control unit of the device (for this reason only two cables are required to connect to the control unit ). The actuator described in this embodiment ensures that the first stroke position is reached insofar as the time to reach the first stroke position is shorter than the threshold time Tt . In a specific application, the concealment time is T1 the threshold time is about 0.5 seconds Tt about 0.8 seconds.

As in 9 shown is the displacement of the slide 23 from the position of the 2a-2b up to the position of the 3a-3b (time period referred to as "opening the lid") caused by a series of relatively more frequent electrical pulses while the slide remains 23 in this position (time period specified as “dwell position 1”) is caused by a series of relatively less frequent electrical pulses. As in 10th As shown in the diagram below, this first lifting sequence (which has "open cover" and "dwell position 1") can be repeated several times (in the example of 10th five times) to guarantee that the lid 5 is actually open at the end of this process. It is clear that theoretically only a single opening cycle is sufficient to open the lid: repetitions are set to counteract sticking effects with wet detergent, which could inadvertently hold the lid in the closed position after the first opening cycle. After each opening cycle there is a time for resetting the slide in the first position as in FIGS 2a-2b (this time is required for the temperature of the SMA wire to decrease and can be, for example, 0.2 seconds). In 10th the upper diagram also shows the duty cycle of a conventional solenoid actuator for comparison.

At threshold time Tt becomes the actuator 20 deactivated and the donor goes 1 in the position of 4a-4b after a cooling time for the SMA wire (for example about 0.2 seconds).

Furthermore, the logic of the control system is programmed to the threshold time Tt change if the current signal is longer than the threshold time Tt Has. In an embodiment in which the duration of the current signal is longer than the threshold time Tt is the logic of the control system of the threshold time Tt changed. The logic of the control system switches from the condition "when the light beam switches from ON to OFF then trigger a position signal" (and consequently the activation signal changes from stronger to less powerful to hold only the position) that was assigned to the first stroke, on the condition "if the light beam switches from OFF to ON, then trigger a position signal". Therefore, at the threshold time Tt When the light goes out to the receiver, the activation signal goes to a stronger one and remains at that level until the light turns on again. The time at which the second signal generation front 23eB the light beam can reach the receiver again, is subsequently called the "release time" T2 designated. At this release time, which is longer than the threshold time Tt , the moving part of the actuator reaches the second stroke position. This release time is not constant due to limit conditions as described for the concealment time. In one version, it can be about 1.3 seconds.

If the slider 23 which differs from the position of the 4a-4b Moved away, again reaches the position of insert B, it triggers the first position signal and remains the position of insert B until the threshold time Tt receive. Because the current signal duration is longer than the threshold time Tt , starts after the threshold time Tt has expired, the moving part of the actuator moves again until the second stroke position is reached (this state is recognized by the sensor when the movement of the second signal generation front 23eB - see insert C - causes the light beam to switch from OFF to ON). However, if the slider 23 the position of the 5a-5b reached and the dosing valve 19th activated, ie when it has completed the second stroke (in 8th also as a hub 2nd designated), reaches the second signal generation front 23eB the slide 23 the position of the insert C in 8th , ie lets the light beam pass and couples the light receiver 27 with the light transmitter 26 . This triggers the one with the light transmitter 26 and the light receiver 27 connected sensing circuit to output a position signal indicating that the second stroke has been completed.

After the position of the 5a-5b and insert C has been reached, the slide remains 23 in this position until a predetermined time is reached. A period of time along which the slider is in the position of the 5a-5b and the insert B remains in 8th referred to as "dwell position 2". The time at which the second signal generation front 23eB fully releasing the light from the emitter is different according to different component tolerances and different operating conditions of the same dispenser. The effect of the configuration described above is for the donor to get a defined feedback system ON position of the slide, which is specific to the actuator, without interacting with the control unit of the device (for this reason, only two cables may be required to connect to the control unit). The total time of the current signal for moving the movable part of the actuator to the second lifting position and holding the movable part in this position can be approximately 8.1 seconds in one embodiment, as in FIG 9 shown.

As in 9 shown is the displacement of the slide 23 from the position of the 4a-4b to the position of the 5a-5b (time period specified as "open valve") caused by a series of relatively more frequent electrical pulses while holding the slide 23 in this position (area referred to as "dwell position 2") is caused by a series of relatively less frequent electrical pulses. The more common electrical pulses are required to give the SMA wire more electrical power (for example, more than 4W), which causes the wire temperature to increase and the wire length to decrease, as is conventionally known for SMA wires. Less frequent electrical pulses allow a power spread for the Joule effect (for example about 2W) which only keep the temperature of the SMA wire constant and consequently also keep the length of the SMA wire constant; in this way the first stroke position is retained.

As in 10th As shown in the graph below, this first stroke sequence (which has "open valve" and "dwell position 2") can be repeated several times (in the example of 10th six times) to guarantee that a certain amount of washing-up liquid is released, in view of the fact that after each activation of (for example 1.8 seconds) a certain amount of washing-up aid has been dispensed.

This design does not require a mechanical system capable of toggling between activation to open the dispenser and activation to dispense rinse aid (as is known in the art and in EP 1 740 082 B1 or EP 1 909 632 B1 described), since the dispenser only provides for opening activation or donation activation based on the duration of the current signal. With a duration of the current signal that is shorter than or equal to the threshold time Tt is and longer than the concealment time T1 , will only open the lid of the dispenser 5 activated; with an activation time that is longer than the release time T2 is activated, the rinse aid pump is activated, and thus the control unit of the dishwasher can change the activation of the dispenser with a time signal control.

According to further embodiments, not shown, the control procedure could ensure that the flushing aid dispensing action is activated without requiring that the movable element temporarily remains in the first lifting position during its movement from the starting position to the second lifting position. In this case, the signal modulation described above would cover time T1 and the threshold time Tt not done.

The 11a and 11b each show a circuit layout and a block diagram of a first example of the modulation circuit used in the printed circuit board 21 can be implemented, and which is capable of performing the signaling and control operations described above. The circuit includes a signal generator 30th that of the light transmitter 26 is assigned to the light receiver 27 as well as a switching unit 40 , and is with a timer circuit 60 and connected to a power stage that is the SMA wire 24th having. The 11c and 11d each show a circuit layout and a block diagram of a second example of the modulation circuit used in the printed circuit board 21 can be implemented, and which is capable of performing the signaling and control operations described above. The circuit includes a microprocessor 70 with the light transmitter 26 and the light receiver 27 is connected, as well as a performance level 50 that the SMA wire 24th having. Of course, other circuit configurations can be considered by those skilled in the art.

In the actuator discussed above, an SMA-based actuator is controlled by changing the duty cycle of the activation signal to achieve a decrease in the SMA wire length to activate the actuator or to maintain the length of the SMA wire to maintain the position reached by the actuator. More generally, according to the present disclosure, a method of controlling the position of a linear actuator, such as an SMA actuator, a solenoid actuator, or a wax actuator, is provided by changing a characteristic of the activation signal, such as pulse intensity, the duty cycle, that Duration of the signal, pulse length, voltage, current or RMS of the signal. Each of these changes in the characteristics of the activation signal is able to change the thermal energy generated by the Joule effect of the SMA wire and to change its own temperature and then its own length. In this regard, the 12a and 12b an example of an alternative waveform in which it is the voltage pulse intensity that is changed. In particular shows 12a the waveform of an activation signal required to move the movable element to the first position (open door) and to keep the movable element in the first position, whereas 12b the Waveform of an activation signal required to move the movable member to the second position (metering valve activation) and to hold the movable member in the second position. On the other hand, they show 12c and 12b another example of an alternative waveform in which a continuous voltage signal is used. In particular shows 12c the waveform of an activation signal required to move the movable element to the first position and to keep the movable element in the first position, whereas 12d shows the waveform of an activation signal required to move the movable element to the second position in order for the movable element to remain in the second position.

In further embodiments, not shown, where the actuator has to reach more than two different operating positions, corresponding series of modulation signals are required using the same procedure as described above.

• - Bereitstellen eines Positionssignals, das eine Position des beweglichen Elements 23 angibt, und
• - Steuern des beweglichen Elements 23 basierend auf dem Positionssignal,

wobei das Steuern des beweglichen Elements 23 aufweist, eine Charakteristik des Aktivierungssignals basierend auf dem Positionssignal zu ändern. Zum Beispiel wird im oben diskutierten Beispiel der Tastzyklus des Aktivierungssignals von dem „Deckel öffnen“-Bereich zu dem „Verweilposition 1“-Bereich geändert, wenn der Abschluss des ersten Hubs des Schiebers 23 durch die Sensiermittel 26, 27 detektiert wird (basierend auf der Position der Front 23eA relativ zu den Sensiermitteln), und der Tastzyklus des Aktivierungssignals von dem „Ventil öffnen“-Bereich zu dem „Verweilposition 2“-Bereich geändert wird, wenn der Abschluss des zweiten Hubs durch den Schieber 23 durch die Sensiermittel 26, 27 detektiert wird (basierend auf der Position der Front 23eB relativ zu den Sensiermitteln 26, 27).Accordingly, a method for controlling a linear actuator 20 specified for an electrical household appliance, the linear actuator 20 at least one solid element 21 , 22 and at least one moving element 23 configured to be in response to an activation signal from a control circuit between at least two different positions relative to the fixed element 21 , 22 is movable, the method comprising the following steps:

• - Providing a position signal, which is a position of the movable element 23 indicates, and
• - Control the moving element 23 based on the position signal,

controlling the movable member 23 comprises changing a characteristic of the activation signal based on the position signal. For example, in the example discussed above, the duty cycle of the activation signal is changed from the "open lid" area to the "dwell position 1" area when the first stroke of the slide is completed 23 through the sensing means 26 , 27 is detected (based on the position of the front 23eA relative to the sensing means), and the duty cycle of the activation signal is changed from the "open valve" area to the "dwell position 2" area when the second stroke is completed by the slide 23 through the sensing means 26 , 27 is detected (based on the position of the front 23eB relative to the sensing means 26 , 27 ).

• - Bereitstellen eines Zeitsignals, und
• - Ändern einer Charakteristik des Aktivierungssignals basierend auf dem Zeitsignal (im näheren Detail basierend auf der Dauer des Zeitsignals). Zum Beispiel wird im oben diskutierten Beispiel der Tastzyklus des Aktivierungssignals vom „Verweilposition 1“-Bereich zum „Ventil öffnen“-Bereich geändert, wenn die Schwellenzeit Tt erreicht wird.

Furthermore, a method for controlling a linear actuator 20 specified for an electrical household appliance, the linear actuator 20 at least one solid element 21 , 22 and at least one moving element 23 configured to be in response to an activation signal from a control circuit between at least two different positions relative to the fixed element 21 , 22 is movable, the method comprising the following steps:

• - Providing a time signal, and
• - Changing a characteristic of the activation signal based on the time signal (in more detail based on the duration of the time signal). For example, in the example discussed above, the duty cycle of the activation signal is changed from the “dwell position 1” area to the “open valve” area when the threshold time Tt is achieved.

• - Bereitstellen eines Positionssignals, das eine Position des beweglichen Elements 23 angibt, und
• - Steuern des beweglichen Elements 23 basierend auf dem Positionssignal gemäß einer Konditionalregel,

wobei das Verfahren ferner aufweist:

• Bereitstellen eines Zeitsignals, wobei das Steuern des beweglichen Elements aufweist, die Konditionalregel basierend auf dem Zeitsignal zu ändern. Zum Beispiel wird im oben diskutierten Beispiel die Konditionalregel des Aktivierungssignals von „wenn der Lichtstrahl von EIN zu AUS schaltet, dann triggere ein Positionssignal“, das dem ersten Hub zugeordnet ist, zu „wenn der Lichtstrahl von AUS zu EIN schaltet, dann triggere ein Positionssignal“, das dem zweiten Hub zugeordnet ist, geändert, wenn die Schwellenzeit Tt erreicht wird. Der hierin verwendete Begriff „Konditionalregel“ bedeutet allgemein, dass dann, wenn eine spezifische Bedingung erfüllt ist, eine spezifische Aktion durchgeführt wird.

Furthermore, a method for controlling a linear actuator 20 specified for an electrical household appliance, the linear actuator 20 at least one solid element 21 , 22 and at least one moving element 23 configured to be in response to an activation signal from a control circuit between at least two different positions relative to the fixed element 21 , 22 is movable, the method comprising the following steps:

• - Providing a position signal, which is a position of the movable element 23 indicates, and
• - Control the moving element 23 based on the position signal according to a conditional rule,

the method further comprising:

• Providing a time signal, wherein controlling the movable member comprises changing the conditional rule based on the time signal. For example, in the example discussed above, the conditional rule of the activation signal changes from "when the light beam switches from ON to OFF trigger a position signal" associated with the first stroke to "when the light beam switches from OFF to ON then trigger a position signal “, Which is assigned to the second hub, changed when the threshold time Tt is achieved. The term “conditional rule” used herein generally means that when a specific condition is met, a specific action is taken.

Combinations of two or more of the control methods mentioned above provide further aspects.

The 13a and 13b show another embodiment of the actuator 20 . In the actuator of the 13a and 13 b elements corresponding to the previous embodiment have been given the same reference numbers. While in the previous versions the actuator was movable between three different positions (ie A, B, C), the actuator is the 13a and 13b moving between a larger number of positions, the respective signal generation front 23eA , 23eB , 23eC , 23eD , ..., can be assigned on the coupling profile 23e the slide 23 are trained. It is clear that in this version not only a threshold time is defined, but more than one ( Tt1 , Tt2 , Tt3 , ...). Each threshold time defines a corresponding activation setpoint length of the actuator. In fact, by defining each threshold time, it is possible to define a length reached and held by the actuator, as previously described.

The 14a and 14b show yet another embodiment of the actuator. In the actuator of the 14a and 14b elements corresponding to the previous explanations have been given the same reference numbers. While in the previous versions the coupling profile 23e the slide 23 Signal generation fronts 23eA , ..., which was orthogonal to the direction of movement of the slide 23 are arranged contains in the execution of the 14a and 14b the coupling profile 23e ' a signal generation fronts 23eK, which is oblique to the direction of movement of the slide 23 is arranged. This ensures a smooth transition between a state in which the light receiver 27 with the light transmitter 26 is optically coupled, and a state in which the light receiver 27 from the light transmitter 26 is optically decoupled. With such a design it would be possible to control the movement and position of the slider 23 proportional to the intensity of the light signal reaching the optical receiver.

Of course, without touching the principle of the invention, the details and structural details of what is described and illustrated merely as a non-limiting example can be changed widely without thereby departing from the scope of the invention as defined in the appended claims is.

Actuator ( 20 ) for an electrical household appliance, which has: at least one fixed element ( 21 , 22 ), at least one movable element ( 23 ) configured to be between at least two different positions relative to the fixed element ( 21 , 22 ) is movable, a shape memory alloy element ( 24th ) with the fixed element ( 21 , 22 ) is operationally engaged and is in connection with the movable element ( 23 ), the shape memory alloy element ( 24th ) is configured to receive an activation signal and, in response, to change its dimension to the movable element ( 23 ) relative to the fixed element ( 21 , 22 ) to move. The actuator also includes a modulation circuit ( 21a ) with which the shape memory alloy element ( 24th ) is electrically connected. The modulation circuit ( 21a ) includes a plurality of electrical connections ( 25a , 25b ), through which the modulation circuit ( 21a ) can be connected to a control unit of the electrical household appliance. The modulation circuit ( 21a ) is configured to convert a current signal from the control unit into an activation signal, which is suitable for the shape memory alloy element ( 24th ) and a position of the movable element ( 23 ) based on a duration of the current signal.

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• EP 1740082 B1 [0008, 0056]
• EP 1909632 B1 [0008, 0056]

Claims (8)

Actuator (20) for an electrical household appliance, comprising: at least one fixed element (21, 22), at least one movable element (23) that is configured in such a way that it is located between at least two different positions relative to the fixed element (21, 22) is movable, a shape memory alloy member (24) operatively engaged with and extending therefrom in connection with the movable member (23), the shape memory alloy member (24) being configured to a Receiving the activation signal and in response changing its dimension to move the movable member (23) relative to the fixed member (21, 22), and the actuator is characterized in that it further comprises a modulation circuit (21a) with which the shape memory alloy element (24) is electrically connected, wherein the modulation circuit (21a) has a plurality of electrical connections (25a, 25b) through which the The modulation circuit (21a) is connectable to a control unit of the electrical household appliance, the modulation circuit (21a) being configured to convert a current signal from the control unit into an activation signal that is suitable for activating the shape memory alloy element (24) and a position of the movable member (23) based on a duration of the current signal. Actuator after Claim 1 characterized in that it further comprises sensing means (26, 27) located on board the modulation circuit (21) and configured to provide a position signal indicative of a position of the movable element (23). Actuator after Claim 2 , characterized in that the modulation circuit (21) is configured to control the shape memory alloy element (24) based on the position signal. Actuator after Claim 3 , characterized in that the modulation circuit (21) has only two of the electrical connections. Actuator according to one of the Claims 2 to 4th , characterized in that the sensing means comprise a light transmitter (26) and a light receiver (27) which are arranged in front of one another, the movable element having a coupling profile (23e; 23e ') which is located between the light transmitter (26) and the light receiver ( 27) is inserted and configured to optically couple the light receiver (27) to the light transmitter (26) or optically decouple the light receiver (27) from the light transmitter (26) based on the position of the movable element (23) . Actuator after Claim 5 , characterized in that the coupling profile (23e ') is designed to ensure a smooth transition between a state in which the light receiver (27) is optically coupled to the light transmitter (26) and a state in which the light receiver (27 ) is optically decoupled from the light transmitter (26). Dispenser (1) for dispensing a detergent and a detergent in a dishwasher, the dispenser (1) comprising: a receptacle (3) which serves to hold an amount of a detergent; a movable cover (5) which is assigned to the receptacle (3) and can be moved from an open position to a closed position in which it opens and closes the receptacle (3) in each case; an automatically controlled closing element (13), which is able to assume a deactivated configuration in which the closing element (13) is configured to lock the lid (5) in the closed position, and an activated configuration in which the Closure member (13) releases cover (5) to allow it to transition from the closed position to the open position; and a metering valve (19) configured to dispense the detergent; the dispenser being characterized in that it has an actuator according to one of the Claims 1 to 6 wherein the movable member (23) of the actuator (20) to a first active position in which the movable member (23) controls the closing member (23) to transition from the deactivated configuration to the activated configuration and to a second active one Position in which the movable element (23) controls the metering valve (19) for dispensing the detergent is movable. An air manifold for a refrigerator having an air duct and an obturator configured to move between different positions, in which the air duct is closed, partially open and fully open, the air manifold being characterized by being one Actuator according to one of the Claims 1 to 6 wherein the movable member of the actuator is operatively connected to the obturator to control the position of the obturator.

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