DE202021101297U1 - Valve, valve assembly and system for a seat comfort function - Google Patents

Abstract

Valve (120) with a valve housing (102), wherein the valve housing has at least a first connection (105) and a second connection (106),
the valve housing (102) enclosing a valve chamber (109), the valve comprising an actuator (103) and a control element (104), the control element (104) being arranged to open or close the first or second port (105, 106). is,
comprising at least one air mass measuring device for measuring an air mass flowing through the valve.

Description

The invention relates to a valve, a valve assembly and a system for a seat comfort function.

According to the prior art, for example, from the DE 10 2017 112 803 A1 a circuit arrangement for controlling a system, in particular a lumbar support with at least two air cushions. The known circuit is therefore suitable for a seat comfort system.

1a-c shows a circuit arrangement for controlling a seat comfort system according to the prior art. A seat comfort system, for example with a pneumatic lumbar support device and/or massage device for a seat, typically includes a plurality of air cushions 130 (not shown), which can be filled and subjected to a desired, possibly time-dependent pressure. For this purpose, the seat comfort system includes a controller, a pump (not shown) for pressurizing the air cushions and a plurality of valves 120, with each air cushion expediently being assigned at least one valve. According to the prior art, each of these valves can comprise an actuator with an SMA element (shape memory element) which, depending on the current flow, puts the valve in an open, partially open or closed functional state. The power supplied usually has to be kept within a very narrowly defined range in order to ensure reliable activation of the actuator while avoiding thermal overload and thus permanent damage to the SMA element. A control device must therefore expediently have sensors for current, voltage and/or temperature monitoring.

In the 1a a known circuit arrangement 1 is shown. The circuit arrangement 1 is suitable for controlling a system 2, in particular a lumbar support with at least two air cushions 130 (not shown). Such a system comprises at least two air cushions which comprise at least one valve, in particular at least one valve each. Such a valve 120 comprises, as exemplified in 1b shown, a housing 102 and an actuator 103. The housing 102 includes a first opening 105 and a second opening 106. The housing encloses a valve chamber 109. The actuator 103 includes an SMA element 100, which is designed as a V-shaped wire arranged , and an actuating element 104 that can be moved with the SMA element 100 and is provided with a sealing element 108 in order to selectively open or close the first opening 105 . The first opening 105 is open when the actuating element 104 is in a first position and is closed when the actuating element 104 is in a second position. From the WO 2005/026592 A2 It is known that such a valve can have a limit switch 107 which is closed when the second position is reached. A heating power supplied to the wire can be partially or completely reduced by means of this limit switch. Furthermore, from the WO 2005/026592 A2 a circuit with a temperature sensor that adjusts the heating output to the ambient temperature.

As an alternative to the in 1b shown actuator with a V-shaped SMA element, an actuator 103 with a linear or U-shaped SMA element 100 is known, in which the actuating element 104 can be formed, for example, from a leaf spring, at the first end of which the SMA element 100 acts . The sealing element 108 can be held in a through hole 104a of the actuating element 104 at the first end of the actuating element. In the example shown, the actuating element 104 is arranged with its other end between a base plate 109 and a circuit board 110 or circuit board, with the SMA element 100 being able to be held and contacted by means of a crimp 101 .

In the 1a The circuit arrangement shown is suitable for energizing and switching a plurality of SMA elements 100-1 to 100-N. The SMA elements are connected to a voltage source U shown with the arrow. For this purpose, the circuit arrangement 1 includes a control unit 30. Furthermore, a temperature sensor 70 for measuring the ambient temperature of the SMA elements 100 and/or a voltage sensor 71 can be present. The control unit 30 is connected to a pulse width modulation unit 60 . The pulse width modulation unit 60 can be used to control the SMA elements 100 by means of pulse width modulation, with the duty cycle of the pulse width modulation, i.e. the ratio of pulse width to period, being adjusted depending on the measured supply voltage and temperature. A circuit for a pulse width modulation is, for example, from DE 10 2017 112 803 A1 famous. The associated SMA element 100-1 to 100-N can be supplied with current in succession by means of the respective driver 20-1 to 20-N. To avoid current peaks, series resistors 21-1 to 21-N can be present. Furthermore, the circuit arrangement can also include a limit switch or a feedback device 38 . The feedback device is either connected to pulse width modulation unit 60, as shown, or alternatively connected to control unit 30, and is suitable for reporting to pulse width modulation unit 60 or control unit 30 when the actuator has reached an end position, which is detected mechanically in particular.

From the DE 10 2016 225 519 A1 discloses a pneumatic valve with an actuator and movable shut-off elements, the actuator being actuated by an SMA element that can be deformed by means of electrical heating power. To actuate the actuator, the SMA element is supplied with electrical heating power, whereupon the SMA element deforms in a manner known per se and this causes a predetermined movement of the shut-off element to open or close an air connection. The deformation of the SMA element is reversed upon termination of the application of the electrical heating power, thereby causing the predetermined movement of the SMA element to be reversed. The known actuator also includes a detection unit in order to detect when an end position is reached and left. The final position is achieved in the embodiment shown by bridging a portion of the SMA element and measuring a resistance reduced by the bridging.

From the DE 10 2015 113 029 A1 a control device for the adjustment of air cushions is known. For the purpose of control, the running time of a pump is recorded and, taking into account the flow rate of the pump, an amount of air supplied to the at least one air cushion or an air volume supplied is determined.

From the DE 10 2015 213 442 a method for monitoring the pressure in a pneumatic seat adjustment device is known. To do this, the pressure in each air chamber or a supply channel is measured with a pressure sensor.

The known methods are based on the fact that a type of switch, which is realized by a toggle switch or a bypass, is actuated in each case at a specific position of the actuating element. Such mechanical switches can be impaired in their function by dirt particles, abrasion, liquids, but also a high switching frequency.

The object of the invention is to specify a valve, a valve arrangement and a system for seat comfort systems and a seat with seat comfort systems, which improves the disadvantages of the prior art. In particular, a valve should be specified that enables contactless detection of a switching position.

This object is achieved with the features of claim 1 with regard to the valve, with the features of claim 7 with regard to the valve arrangement and with the features of claim 10 with regard to the system. Appropriate configurations result from the respective dependent claims.

A circuit arrangement for controlling a valve, in particular a valve of a system for a seat comfort function, includes at least one actuator with at least one control element, the control element being adjustable between a first position and a second position. The system comprises at least one actuator with at least one actuating element, the actuating element being adjustable between a first position and a second position. For the purposes of this application, the first position and the second position are two positions that are different from one another and can be selected as an open and closed position or as an intermediate position. In one embodiment, the system consists of one or more valves which are used in a lumbar support device or massage device, for example in a vehicle seat, or includes one or more such valves. The actuator can, for example, comprise a piezoelectric element, a magnetic element, in particular an electromagnetic element or an SMA element. Such an SMA element (shape memory alloy element) is in particular a wire or ribbon made from an SMA. A lordosis support device or massage device comprises in particular one or more air cushions arranged in a seat, in particular a vehicle seat.

The circuit arrangement includes at least one air mass measuring device for measuring an air mass flowing through the valve. An air mass can be determined using a measuring wire and a temperature change caused on the measuring wire by the air mass flowing past, for example. Thus, the amount of air flowing through the valve can be determined. Based on the air mass flowing through the valve, it can thus be determined or at least estimated how much air is in the assigned air cushion of the system for a seat comfort function.

The circuit arrangement also has at least one driver unit for actuating the actuator and a control unit for controlling the driver unit, which is suitable for processing an output signal from the air-mass measuring device. In one embodiment, a driver unit includes an SMA driver. A resistance can be measured by means of the air mass measuring device and an output signal can be generated. The output signal is passed on to the control unit so that the control unit can regulate the driver unit based on the measured air mass. The circuit arrangement is expediently designed so that either the air mass is measured with the wire, eg SMA element, or current is supplied, ie air mass measuring device and driver unit are operatively connected in alternation. This can in particular whose control unit also controls the air mass measuring device.

1. a. eine Widerstandsmessvorrichtung zur Messung des Widerstands des Drahtes und/oder
2. b. einen Temperatursensor zur Messung einer Temperatur des Drahtes oder der Umgebungstemperatur des Drahtes und/oder
3. c. Strommesser zur Messung eines Heizstroms und/oder
4. d. Leistungsmessvorrichtung zur Messung einer Eingangsleistung

auf. Die Änderung der Messwerte ist abhängig von der dem Draht, insbesondere dem SMA-Element, entzogenen Wärmemenge durch die vorbeistreichende Luft und somit zu bestimmende Luftmasse. Im Sinne dieser Erfindung soll unter Widerstand der elektrische Widerstand verstanden werden. Das Ausgangssignal des Sensors oder der jeweiligen Messvorrichtung wird an die Steuereinheit weitergegeben, sodass die Steuereinheit die Treibereinheit basierend auf dem gemessenen Wert des Sensors oder der Messvorrichtung regeln kann. Die Schaltungsanordnung kann dazu ausgelegt sein, dass entweder der Widerstand, Strom oder Leistung des Drahtes, z.B. des SMA-Elements, gemessen wird oder eine Bestromung erfolgt, somit also Messvorrichtung und Treibereinheit alternierend wirkverbunden werden. Im Falle einer Temperaturmessung kann ebenfalls Messung und Ansteuerung der Treibereinheit gleichzeitig oder alternierend erfolgen. Dazu kann insbesondere die Steuereinheit auch die Widerstandsmessvorrichtung, den Temperatursensor, den Strommesser oder die Leitungsmessvorrichtung steuern.In an embodiment, the air mass measuring device has a wire and

1. a. a resistance measuring device for measuring the resistance of the wire and/or
2. b. a temperature sensor for measuring a temperature of the wire or the ambient temperature of the wire and/or
3. c. Ammeter for measuring a heating current and/or
4. i.e. Power measuring device for measuring an input power

on. The change in the measured values depends on the amount of heat withdrawn from the wire, in particular the SMA element, by the air passing by and thus the air mass to be determined. For the purposes of this invention, resistance should be understood to mean electrical resistance. The output signal of the sensor or the respective measuring device is forwarded to the control unit, so that the control unit can regulate the driver unit based on the measured value of the sensor or the measuring device. The circuit arrangement can be designed so that either the resistance, current or power of the wire, eg of the SMA element, is measured or current is supplied, ie the measuring device and driver unit are operatively connected in alternation. In the case of a temperature measurement, the driver unit can also be measured and controlled simultaneously or alternately. For this purpose, in particular, the control unit can also control the resistance measuring device, the temperature sensor, the ammeter or the line measuring device.

In one embodiment, the control unit can have additional sensors for current, voltage and/or temperature monitoring. In one refinement, the control unit has communication interfaces in order to be controlled via switches and/or an on-board computer that are present in a vehicle. As a further input, the control unit can have a LIN (Local Interconnect Network) communication interface, which in particular has a transceiver and/or has a switch input interface. The switch input interface is particularly suitable for processing resistance-based switch signals, it being possible for the switch input interface to be designed for a plurality of switch inputs, e.g. seat adjustment, in particular position and lumbar support, and massage. The control unit may include memory for storing data.

1. a. der Temperatur des Drahtes und dem Heizstrom,
2. b. der Temperatur des Drahtes und der Eingangsleistung,
3. c. dem Widerstand des Drahtes und dem Heizstrom oder
4. d. dem Widerstand des Drahtes und der Eingangsleistung ermittelt.

In a further embodiment, the air mass is

1. a. the temperature of the wire and the heating current,
2. b. the temperature of the wire and the input power,
3. c. the resistance of the wire and the heating current or
4. i.e. the resistance of the wire and the input power.

The wire of the mass air flow sensor is either the respective SMA element or a wire arranged separately from the SMA elements. A wire separate from the SMA element may be a wire comprising an SMA material, or another metallic material such as tungsten or platinum, or an alloy. Such a wire can, for example, be connected in parallel with the SMA elements, but driven differently from them.

In one embodiment, the circuit arrangement includes a resistance measuring device or additional resistance measuring device, the circuit arrangement being designed such that the resistance measuring device and driver unit are operatively connected alternately to the wire, in particular to the SMA element, and to the actuator, in particular to the SMA element.

The circuit arrangement expediently includes an evaluation unit or is connected to it. The evaluation unit is connected between the resistance measuring device, the temperature sensor, the ammeter or the line measuring device on the one hand and the control unit on the other hand, so that the measured resistance value, temperature value, amount of current or power is measured, evaluated with the evaluation unit and an output signal from the evaluation unit given to the control unit. This output signal can in particular include a signal for communicating that an end condition has been reached.

In one configuration, the circuit arrangement includes an application-specific integrated circuit which has one or more of the following components: driver, measuring device, evaluation unit, memory or control unit. The design with an ASIC makes the circuit smaller and can be manufactured more cheaply. The measuring device can be a temperature measuring device, resistance measuring device, current measuring device and/or power measuring device.

In a further embodiment, the circuit arrangement includes additional sensors, in particular an end position switch. For example, such an end position switch can serve both as a safety measure and as a calibration aid.

In one refinement, the circuit arrangement comprises a large number of actuators, with each actuator being assigned a driver unit, in particular a driver unit with an SMA driver for actuating the respective actuator or an SMA driver in a driver unit for each actuator. The circuit arrangement expediently comprises a multiplexer which is connected to each of the SMA elements of the actuator in such a way that the resistance of each SMA element can be measured individually. Thus, by means of the multiplexer, each SMA element is sequentially connected to the resistance measuring device for measuring the resistance.

In a further refinement, the evaluation unit comprises a memory for storing data, with the evaluation unit evaluating a course of successively measured values, in particular measured temperature values, measured current values, resistance values or (input) power values, of the same SMA element and/or compares it with one or more predetermined resistance values . Alternatively, the memory can also be a shared memory of the evaluation unit and the control unit.

The control unit is expediently designed for control using pulse width modulation. For this purpose, the control unit expediently includes a pulse width modulation unit. Thus, the SMA elements are energized one after the other within a duty cycle for a predetermined pulse width and pulse height via the assigned SMA driver of the driver unit and are thus heated. In one embodiment, the pulse width modulation unit can output a time signal to the resistance measuring device and/or air mass measuring device.

The evaluation unit includes a signal amplifier and/or a noise suppressor.

In one configuration, the resistance measuring device comprises two or more multiplexers, which are each connected to a part of the SMA elements. This configuration is possible for large systems with a large number of SMA elements. For example, 20 SMA elements can be provided per multiplexer.

A series resistor is expediently connected in series between the resistance measuring device and the SMA element. This series resistor essentially serves to reduce current peaks and thus reduces the risk of overloading the SMA elements.

1. a. Messen einer Luftmasse,
2. b. Nachfolgend Ansteuern des Aktuators, insbesondere des SMA-Elementes mittels eines Treibers in Abhängigkeit der gemessenen Luftmasse,
3. c. Zyklisches Widerholen des Messens und Ansteuerns bis zum Erreichen einer Endbedingung.

A method for controlling a circuit arrangement, in particular a circuit arrangement described above, comprises:

1. a. measuring an air mass,
2. b. Subsequent activation of the actuator, in particular the SMA element, by means of a driver depending on the measured air mass,
3. c. Cyclic repetition of measurement and activation until an end condition is reached.

The end condition is or includes one of reaching a predetermined air mass value, a predetermined change or a fill level.

When an SMA element is heated, in particular when a heating current flows through the SMA element, its resistance changes. Such a change in resistance has been published, for example, by the song "Resistance modeling of SMA Wire actuators", International Workshop Smart Materials Structures & NDT in Aerospace, NDT in Canada 2011. A change in resistance can thus be assigned to a predetermined change in length, in particular a shortening. However, the change in resistance is not linear, but includes linear and near-linear regions. Experiments have shown that an increase in the resistance curve has a sign reversal when the actuator reaches an end point, so that the resistance curve has a reversal point, i.e. a zero crossing of the second derivative of the resistance curve. The reversal point can be determined by comparing it with the previously measured resistance value or values. A combination of detection of the reversal point and comparison with a specified absolute value increases the accuracy of the method. If a wire with a different material, e.g. a metal, is used to determine the air mass, the relationship between resistance and temperature is different.

In particular for normal operation, the end condition can be selected such that the actuating element is brought into an intermediate position close to the open or closed position, so that an end point of the actuator is not reached with the method according to the invention. This reduces the mechanical stress on the valves.

The method expediently includes activation by means of pulse width modulation.

1. a. Messen eines Widerstands des Drahtes und/oder
2. b. Messen einer Temperatur des Drahtes und/oder
3. c. Messen einer Umgebungstemperatur des Drahtes und/oder
4. d. Messen eines Heizstroms des Drahtes und/oder
5. e. Messen einer Eingangsleistung des Drahtes.

In an embodiment, the method also includes

1. a. measuring a resistance of the wire and/or
2. b. measuring a temperature of the wire and/or
3. c. measuring an ambient temperature of the wire and/or
4. i.e. measuring a heating current of the wire and/or
5. e. measuring an input power of the wire.

The method can also include measuring the resistance of all SMA elements, with the resistance of all elements being measured in a common activation dead time, or with an element being measured between the activation of the SMA element and the activation of the subsequent element.

In a further refinement, the power required for activation is calculated by means of the driver or read from a table.

The valve according to the invention comprises a valve housing. The valve housing includes in particular a housing cover, a housing base and an intermediate housing arranged between the housing cover and the housing base.

The valve housing has at least a first connection and a second connection, and the valve housing encloses a valve chamber. This may include a flow chamber and an actuation chamber. The valve includes an actuator with an actuating element for opening and closing the valve, and expediently a restoring element. In one configuration, the actuating element is used for directly closing the first or second connection. The actuator may include an SMA element.

A circuit arrangement as described above can be provided to control the valve.

The valve housing can have at least one valve opening leading from the flow chamber into the actuation chamber, and the actuating element, which can be moved axially between a closed position for closing the valve opening and an open position for releasing the valve opening, inside the actuating chamber, has a wire or strip-shaped SMA element made of a shape memory alloy, a restoring element serving to move the actuating element in the closing direction and a circuit board are arranged, wherein the SMA element is fixed with a section on the actuating element and is electrically connected to the circuit board at least one end for the application of current .

In an expedient refinement, the SMA element is fixed to the actuating element with a middle section and is connected to the printed circuit board with both ends.

The wire of the circuit arrangement is expediently arranged in the valve chamber of the valve.

A valve arrangement can be formed with a plurality of valves described above. The valve housings that enclose the valve chamber of a valve, in particular the intermediate housings and/or housing covers and/or housing bases, and/or printed circuit boards, are designed in one piece.

The valve according to the invention comprises a valve housing. The valve housing includes in particular a housing cover, a housing base and an intermediate housing arranged between the housing cover and the housing base.

The valve housing has at least a first connection and a second connection, and the valve housing encloses a valve chamber. This may include a flow chamber and an actuation chamber. The valve includes an actuator, a control element for opening and closing the valve, and expediently a restoring element. In one configuration, the actuating element is used for directly closing the first or second connection. The actuator may include an SMA element. Alternatively, the actuator can also include a piezoelectric element or a magnetic element.

The valve comprises at least one air mass measuring device for measuring an air mass flowing through the valve. Thus, the amount of air flowing through the valve can be determined. Based on the air mass flowing through the valve, it can thus be determined or at least estimated how much air is in the assigned air cushion of the system for a seat comfort function.

The valve housing can at least one of the flow chamber into the actuation chamber opening into the valve opening, wherein within the actuation chamber the actuating element that can be moved axially between a closed position for closing the valve opening and an open position for releasing the valve opening, a wire-shaped or band-shaped SMA element made of a shape-memory alloy that serves to actuate the actuating element in the opening direction, a Adjusting element in the closing direction serving return element and a printed circuit board are arranged, wherein the SMA element is fixed with a section on the actuating element and is electrically connected to the application of electricity with at least one end to the printed circuit board.

In one embodiment, the air mass measuring device comprises a wire and a resistance measuring device for measuring the resistance of the wire and/or a temperature sensor for measuring a temperature of the wire or an ambient temperature of the wire and/or an ammeter for measuring a heating current and/or a power measuring device for measuring an input power.

The wire may be the wire or ribbon shaped SMA element, or the wire may be an element other than wire or ribbon shaped SMA element. In principle, the SMA element and a separate wire can also be used for the measurement.

The wire is expediently arranged in the flow chamber, or in an embodiment with a separate wire is arranged in the first or second connection.

In one embodiment, the valve arrangement has a plurality of valves, each configured as described above, with the valve housings enclosing the valve chamber of a valve, in particular the intermediate housings and/or housing covers and/or housing bases, and/or circuit boards being configured in one piece.

In one refinement, at least a first part of the plurality of valves has a common pressure connection, which in each case opens into the valve space, in particular into the flow chamber, particularly preferably into a first area of the flow chambers or an area comprising the first areas of the flow chambers, or in each case with the valve space, in particular the flow chamber, particularly preferably the first area of the flow chamber or the area is connected via at least one air duct, and/or wherein at least a second part of the plurality of valves has a common opening for connection to the atmosphere, which is in particular in the first area of the flow chamber or opens into an area comprising the first areas of the flow chambers or is connected to the first areas of the flow chambers. The wire can be accommodated in each valve, in particular as an SMA wire.

As an alternative to the embodiment described above, the wire is not accommodated in each valve of the valve arrangement, but the wire of the air mass measuring device is arranged in the air duct or the common opening for connection to the atmosphere.

In a further refinement, the air mass measuring device is connected to a circuit arrangement in such a way that the air mass measurement is only carried out when precisely one valve is open.

In one embodiment, a system for a seat comfort function includes one or more valves and/or a valve arrangement, and also includes one or more air cushions, the fill level of each air cushion being controllable via at least one of the valves.

At least a first part of the several valves expediently has a common pressure connection, which is connected to the valve space, in particular the flow chamber, particularly preferably the first area of the flow chamber or the area via at least one air duct, and/or wherein at least a second part of the several valves has a common opening for connection to the atmosphere, which opens in particular into the first area of the flow chamber or an area comprising the first areas of the flow chambers or is connected to the first areas of the flow chambers, the air mass measuring device having a wire for each valve or for a first portion of the plurality of valves and for a second portion of the plurality of valves.

The several valves can have a common pressure connection, which in each case opens into the valve space, in particular into the flow chamber, particularly preferably into the first area of the flow chambers of the valves or an area comprising the first areas of the flow chambers, or in each case with the valve space, in particular the flow chamber, is particularly preferably connected to the first area of the flow chambers or the area via at least one air duct, and each valve has a separate opening for connection to the atmosphere, which opens in particular into the second area of the flow chamber.

The valve spaces of the plurality of valves can be separated from the electronic control accommodating space Contacting of the printed circuit board can be separated by a partition, the partition being in particular formed in one piece with the intermediate housing, and/or the valves and the valves being separated from one another by a partition, the partition being in particular formed in one piece with the intermediate housing, the partitions have a passage opening for the printed circuit board that is pneumatically sealed in the assembled state.

Guide elements can be arranged in an air duct leading from the air supply unit of the valve arrangement to the flow chamber or chambers in such a way that a fluid flowing into and/or through the flow chambers has a laminar flow.

The system according to the invention for a seat comfort function includes one or more valves and/or a valve arrangement and also includes one or more air cushions, the fill level of each air cushion being controllable via at least one of the valves.

The seat includes a seat comfort system with the circuit arrangement.

• 1a Schaltungsanordnung nach dem Stand der Technik,
• 1b SMA-Ventil mit einem Aktuator,
• 1c alternative Ausgestaltung eines Aktuators,
• 2 erste Ausgestaltung einer Schaltungsanordnung,
• 3 Ausgestaltung eines SMA-Ventils,
• 4 zweite Ausgestaltung einer Schaltungsanordnung,
• 5 dritte Ausgestaltung einer Schaltungsanordnung,
• 6 ASIC,
• 7 Ausgestaltung einer Ventilanordnung und
• 8 System

The invention is explained in more detail below, also with regard to further features and advantages, on the basis of the description of exemplary embodiments and with reference to the accompanying drawings. They each show in a schematic principle sketch:

• 1a Circuit arrangement according to the state of the art,
• 1b SMA valve with an actuator,
• 1c alternative design of an actuator,
• 2 first embodiment of a circuit arrangement,
• 3 design of an SMA valve,
• 4 second embodiment of a circuit arrangement,
• 5 third embodiment of a circuit arrangement,
• 6 ASIC,
• 7 Design of a valve assembly and
• 8th system

2 shows a first embodiment of a circuit arrangement 1. The circuit arrangement 1 is provided with the SMA elements 100 which, in particular, are as in FIGS 1b and c shown are part of an actuator and thus a valve, designed for a seat comfort system.

The circuit arrangement 1 includes a measuring device 5 and a control unit 30. The measuring device 5 forms an air mass measuring device with the SMA wire. The measuring device can be designed as a resistance measuring device, a temperature measuring device, a current measuring device or a power measuring device. The measuring device 5 can be connected to each of the SMA elements 100-1 to 100-N. The SMA elements are connected to a voltage source U shown by the arrow. The control unit 30 is connectable or permanently connected to the SMA drivers 20 with each of the SMA elements 100 - 1 to 100 -N. The SMA drivers 20 are arranged in a driver unit 6 . The measuring device 5 generates an output signal which is transmitted by cable or wirelessly to the control unit 30 and is used there as an input signal for controlling the SMA driver 20 .

The measuring device 5 optionally includes a multiplexer 12 which can be or is connected to each of the SMA elements 100 so that a resistance of one of the SMA elements 100 is measured in particular by applying a measuring current using a current source 13 . Furthermore, a signal amplifier 14 is expediently provided in the measuring device 5, which can have an offset correction. The measurement signal obtained for the air mass can now be evaluated in an evaluation unit 8 to determine the air mass. In the example shown, the evaluation unit is arranged in the measuring device 5 . Alternatively, it can be arranged as a separate component between measuring device 5 and control unit 30 .

In the 2 The circuit arrangement shown can have a control unit 30, which is designed to actuate the SMA elements 100-1 to 100-N by means of pulse width modulation.

3 shows an alternative embodiment of a valve. In this valve is in contrast to 1B , the wire not the SMA wire, but the wire 140 can be placed in different positions in the valve. In particular, the wire 140 can be arranged as a wire 141 in the second opening 106 and/or as a wire 142 in the first opening 105 of the valve. Alternatively or additionally, the wire of the measuring device 5 can also be arranged as a wire 143 in a flow chamber of the valve.

4 shows an embodiment of the circuit arrangement 2 , in which separate wires 140 are arranged in the respective valves, so that the air mass measuring device the Mes solution on the wires 140 and the drivers drive the SMA wires 100 of the valves. The separate wires 140 are connected in parallel with the SMA wires 100 in the embodiment of the drawing shown, however, the separate wires for the measurement are driven solely for the measurements. In addition to the actuation, a resistance, for example, can also be measured on the SMA wires 100 by means of the circuit arrangement. The number M of separate measurement wires 140 and the number N of SMA wires can be the same or different. If the actuator controls the setting element with a piezoelectric element or magnetic, in particular electromagnetic element instead of an SMA element, this can be controlled analogously to the SMA elements.

5 shows a second embodiment of a circuit arrangement 1. The circuit arrangement 1 differs from that in 2 shown arrangement by the series resistors 21-1 to 21-N, which are respectively connected by the SMA elements 100-1 to 100-N. Optional are also here as in 4 shown, in addition to the N SMA elements M separate wires 140 are arranged, before each of which a series resistor 23 is connected. Furthermore, the arrangement differs in that a filter 16 is also arranged in the measuring device 5 in addition to the amplifier 14 . In principle, a plurality of filters and amplifier stages or integration elements whose circuitry for signal improvement is known can also be used.

In the embodiment shown, the evaluation unit 8 comprises a memory 36. However, an external memory which the evaluation unit 8 can access is also possible.

In addition to the input 31 shown here, which can in principle also be present in the other configurations, the control unit 30 also includes a pulse width modulation device which is connected to the driver unit 6 and thus to the drivers 20 - 1 to 20 -N. Optionally, the control unit 30 can be designed to control the measuring device 5 . As already based on 4 described, separate wires 140 can also be easily integrated into the circuit arrangement.

6 shows an ASIC. This ASIC 4 can include one or more of driver 20, measuring device 5, evaluation unit 8, memory 36, control unit 30, pulse width modulation unit 60, amplifier 14 or filter 16. Furthermore, if the ASIC includes the control unit 30, the ASIC can in particular also include the input 31, for example for the input of a control signal, which can be transmitted wirelessly or by cable.

In 7 1 is a view of a valve assembly showing a section of an intermediate housing 208. FIG. Via a common pressure connection 270, which can be connected to a pneumatic pump, the flow chambers, more precisely the first areas of the flow chambers of a first part of the valves 120a, in this case four valves 120a, are connected via a pressure port formed by the intermediate housing 208 and delimited on the upper side by the intermediate housing 208 Air channel 276 supplied air (indicated by dashed arrows). A check valve 272 is arranged within the air channel 276 between the pressure connection 270 and a region 282 . A damping foam 274 is also arranged inside the valve housing in order to reduce noise development, in particular when venting the valves 120 .

The first areas 224a of the valves 120 together form the area 282 into which the air duct 276 opens, ie the end section of the air duct 276 . However, it would also be conceivable to separate the first areas 224a from each other by partition walls, so that the first areas 224a each form an end section of the air duct 276 . Air flowing into the first regions 224a is substantially retained in the first regions 224a when the valve opening is closed. However, there is a small exchange of air between the flow chamber 224 or the first regions 224a and the respective actuation chamber 26 of the valve 2 via air gaps, so that pressure equalization is ensured. In addition, a desired cooling of the SMA elements 100 can be set or heat can be dissipated from the actuation chamber 226 via the dimension of the gap.

A second part of the valves 120, here four valves 120b, has a common opening 232 to the atmosphere, via which the first areas 224a of the flow chambers 224 of the second part of the valves 120b or a first area 224a of the valves 120b comprehensive area 284 with the atmosphere are connected. If an air cushion is deflated, the air it contains first flows via the respective consumer connection 230a, b, c, d into the air ducts 278a, b, c, d or the second areas 224b and then via the open valve opening 14 of the valves 120 and the Connecting duct 224c into area 284. Here, too, when valve opening 14 is open, air is exchanged between area 284 and the actuating chambers 26 of valves 120 via the air gaps.

The second regions 224b of the flow chambers of a first valve 120a and a second valve 120b are fluidic in pairs with one another and with one of the present four consumer connections 230a, b, c, d for four media memory or air cushion connected. Each media reservoir or air cushion is assigned one of the air ducts or air chambers 278a, b, c, d, with the air ducts 278a, b, c, d as well as the areas 282, 284 and the areas 284, 286 being partition walls 280, 288 are in turn formed integrally with the intermediate housing 208 or are formed by this. In other words: a first valve 120a and a second valve 120b are assigned to an air cushion and connected to it, the first valve 120 being used to fill the air cushion with air and the second valve 120 to be used to empty the air cushion.

The pressure area 282, the ventilation area 284 and the electronics area 286 are each separated from one another by partitions 280, 288 formed by the intermediate housing 208 and are pneumatically sealed from one another. In order to achieve a sealed transition 290 of the printed circuit board 22 between the printing area 282 and the ventilation area 284 and between the ventilation area 284 and the electronics area 288, an adhesive is applied to the transition in the partition wall 288 through an opening in the printed circuit board 222, which adhesive settles into distributed in the space between circuit board 222 and partition wall 288 and can be cured, for example, by UV light.

In such a valve arrangement, which is shown here in a non-limiting manner, the SMA wires of the valves 120 can be used as the wire of the air mass measuring device or separate wires 140 can be used. Here, too, the arrangement is in an area exclusively assigned to the respective valve, as in 3 shown as an example possible. Alternatively, a wire 140 may be placed in a common air passage 176, marked wire 144, or in the common pressure port 270, marked wire 145, or in the area of cushioning foam 174, marked wire 146.

8th shows a system for a seat comfort function. In the illustration shown, the system comprises a valve 302 which has a first valve opening 310 , a second valve opening 311 and a third valve opening 312 . The first valve port is connected to a pump 300 via a fluid line 320 . The second valve opening 311 is connected to an air cushion 330 via a fluid line 321 . The third valve port 312 is connected to the atmosphere port 340 via another fluid line 322 . One or more air mass measuring devices, in particular the wires of the air mass measuring devices, can be arranged, for example, in fluid line 320 with reference number 305a and/or in fluid line 321 with reference number 305b and/or in fluid line 322 with reference number 305c and/or in the valve with reference number 305d . In a multiple air bag system, the multiple air bags may be connected to one or more valves. In particular, several air cushions are connected to a valve arrangement, the valve arrangement being, for example, 7 essentially the in 8th valve 302 shown would replace, and instead of the one air bag shown, multiple air bags could be connected in parallel to the valve assembly. The air mass measuring devices can then be arranged accordingly in the valve arrangement or in the respective fluid lines.

Reference List

1

circuit arrangement

2

system

4

ASIC

5

resistance measuring device

6

driver unit

8th

evaluation unit

12

multiplexer

13

power source

14

signal booster

16

filter

20

SMA driver

21

series resistor

23

series resistor

30

control unit

31

input

36

Storage

38

feedback device

40

pump driver

50

current sensor

60

pulse width modulation unit

70

temperature sensor

71

voltage sensor

100

SMA element

101

crimp

102

valve body

103

actuator

104

actuator

104a

through hole

105

first opening

106

second opening

107

limit switch

108

sealing element

109

base plate

110

circuit board

120

Valve

130

air cushion

140

wire

141...146

separate wire

208

intermediate housing

224

flow chamber

226

actuation chamber

230

consumer connection

270

pressure connection

272

check valve

276

air duct

278

air duct

282

area

284

area

300

pump

302

Valve

305a...d

air mass measuring device

310

first valve opening

311

second valve opening

312

third valve opening

320

fluid line

321

fluid line

322

fluid line

330

air cushion

340

atmospheric vent

u

voltage source

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely 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

• DE 102017112803 A1 [0002, 0006]
• WO 2005/026592 A2 [0004]
• DE 102016225519 A1 [0007]
• DE 102015113029 A1 [0008]
• DE 102015213442 [0009]

Claims (12)

Valve (120) with a valve housing (102), the valve housing having at least a first connection (105) and a second connection (106), the valve housing (102) enclosing a valve chamber (109), the valve comprising an actuator (103) and a control element (104), the control element (104) being arranged to open or close the first or second port (105, 106). is, comprising at least one air mass measuring device for measuring an air mass flowing through the valve. valve (120) after claim 1 , wherein the actuator comprises a SMA element (100). valve (120) after claim 1 or 2 , wherein the valve housing (102) comprises a housing cover (206), a housing base (210) and an intermediate housing (208) arranged between the housing cover (206) and the housing base (210), the valve space (109) being divided into a flow chamber (224 ) and an actuation chamber (226), wherein in the valve housing (109) at least the valve opening (214) opening from the flow chamber (224) into the actuation chamber (226) has, and wherein within the actuation chamber (226) at least one between a closed position for closing the valve opening (214) and an open position for releasing the valve opening (214), axially movable actuating element (104) and a restoring element (120) serving to move the actuating element (104) in the closing direction and a printed circuit board (122) are arranged, with in particular the SMA element (100) is fixed with a section on the actuating element (104) and is connected to the printed circuit board (22) at least at one end for the application of current is critically connected valve (120) after claim 1 or 2 , wherein the air mass measuring device comprises a wire and a. a resistance measuring device for measuring the resistance of the wire and/or b. a temperature sensor for measuring a temperature of the wire or an ambient temperature of the wire and/or c. an ammeter for measuring a heating current and/or d. comprises a power measuring device for measuring an input power. valve (120) after claim 2 and 4 , wherein the wire (140) is the wire or ribbon-shaped SMA element (100). valve (120) after claim 2 and 4 , wherein the wire (140) is an element (141, 142, 143, 144, 145) other than a wire or ribbon-shaped SMA element (100). valve (120) after claim 5 wherein the wire is disposed in the valve chamber (109), or is disposed in the first or second port (105, 106). Valve arrangement (100) with several, in particular each after claim 1 until 7 formed valves (120), the valve housing (109) enclosing the valve chamber (109) of a valve (120), in particular the intermediate housing (208) and/or housing cover (206) and/or housing base (210), and/or printed circuit boards (222) are formed in one piece. Valve assembly (100) after claim 8 , wherein at least a first part of the plurality of valves (120) has a common pressure connection (270), which opens into the valve space (109), in particular the flow chamber (224), or each connects to the valve space (109), in particular the flow chamber (224 ) or the area (282) via at least one air duct (276), and/or wherein at least a second part of the plurality of valves (120) has a common opening for connecting to the atmosphere, which opens in particular into the first area (224a) of the flow chamber (224). Valve assembly (200) with several each after claim 5 or 6 formed valves (120), wherein at least a first part of the plurality of valves (120) has a common pressure connection (270) which opens into the valve space (109), in particular the flow chamber (224), or each connected to the valve space (109), in particular the flow chamber (224) or the area (282) via at least one air duct (276), and/or wherein at least a second part of the plurality of valves (220) has a common opening for connecting to the atmosphere, which is in particular in the first portion (224a) of the flow chamber (224), wherein the wire of the mass air flow sensor is located in the air duct (276) or common opening for connection to the atmosphere. Valve assembly (200) after claim 10 , wherein the air mass measuring device is connected to a circuit arrangement in such a way that the air mass measurement is only carried out when exactly one valve is open. System for a seat comfort function comprising one or more valves according to one of Claims 1 until 7 and/or a valve assembly (200) after one of the Claims 8 until 11 , further comprising one or more air cushions, wherein the filling level of each air cushion can be controlled via at least one of the valves.

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