DE19848081A1 - Drive device with an actuator - Google Patents

Abstract

The invention relates to a drive device, in particular a locking device, with an actuator for driving a movable element and a position detection device for detecting the position of the movable element Magnetic element arranged Hall element, wherein the Hall element is integrated in an electronic module.

Description

The invention relates to a drive device with an actuator and a position detection device according to the features of The preamble of claim 1.

One such is from American patent 5,240,296 Drive device known, here as a locking device for a door of a vehicle is formed, wherein one designed as a lever Move the movable element from an actuator to two positions can be, and the lever lock the locking device and can unlock.

A potentiometer is used as the position detection device, whose conductor tracks are printed on a circuit board, these Traces of grinders attached to the lever are scanned become. Depending on the position of the lever, the Position "locked" or "unlocked" detected and still the  Actuator switched on depending on the detected position or switched off.

The mode of operation and the control of the actuator as well as the Position detection of the movable element works on and for satisfactory so that the desired positions are recognized can be.

The main disadvantage here is that the Position detection device the harsh environmental conditions, straight as they prevail in vehicles, which (here are too name: temperature fluctuations, humidity, dust and the like) can lead to malfunction of the position detection device. In addition, a trained as a potentiometer is subject Position detection device a wear that is just in the Use in vehicles where the locking device operates very frequently will occur. Here you could think of appropriate materials, which are subject to less wear and tear; this However, they are usually cost-intensive and especially with one Cost reduction cannot be used in series production.

Furthermore, one designed as a potentiometer Position detection device has the disadvantage that the Set the transition point between grinder and conductor track can lead to a falsification of the displayed position, so that even here the correct position is not always reliable is played. However, the position is correctly reproduced absolutely necessary in the application of the locking device, because, for example, the actuator and thus the entire Locking device can be in the "locked" state while the  Position detection "unlocked" displays, so that the actuator would not be driven at all, since the position detection device indicates that the actuator is already in the "unlocked" position is located and thus opening the door would be possible.

The invention is therefore based on the object at the outset described drive device with an actuator and To improve position detection device so that the Disadvantages described are avoided, so that there is a reliable Operation with the simplest structure results.

This object is solved by the features of claim 1.

According to the invention it is provided that the position detection device a magnetic element attached to the movable member and a Hall element arranged in the vicinity of the magnetic element, the Hall element being integrated in an electronic module.

To record the position of the movable element, you make yourself take advantage of the physical Hall effect, which is briefly described at the end.

Now that the movable element and the Position detection device no longer touch, it works Position detection device contactless and therefore wear-free, see above that thereby the function of the drive device over the entire own lifespan or over the entire lifespan of Object in which it is installed (for example a vehicle) works reliably. The construction and assembly of the invention Drive device is particularly simple because there is no alignment between the magnetic element and the Hall element must be done and a  Approach with sufficient accuracy is sufficient to ensure the function of the Ensure position detection device. In addition, this is not applicable Application of conductor tracks on the circuit board as well as that Presence of grinders and grinder carriers one Potentiometers, which are particularly complex when one Scanning the position over several revolutions of the movable Element should take place.

In a further development of the invention, the electronic component is an ASIC educated. An electronic component is closed under an ASIC understand who is manufacturing or programming for his Purpose and the tasks in question was specified. An ASIC contains input and output circuits, memories, Processors, monitors (for temperature, voltage, short circuit and the like), sensors (for example, the Hall element) and so further. This has the advantage that an integrated module on the smallest Space is available. Other advantages are the reduced Quiescent current consumption to name, because only such functions implemented are, which are required for the respective application, and therefore also reduced manufacturing costs. Testing an ASIC is simplified this also because not all functions of one normally used multifunctional chips must be tested. Important is still a very good copy protection, since the ASIC from the outside is not you can see which components it contains and which functions with it are realized. The integration of the sensor means that So-called active sensor is available, which is an already evaluated, if necessary, filtered signal available for further processing poses. The signal processing at the detection location can also Sensitive and small measured variables recorded, amplified and evaluated be passed on, thereby reducing the sensitivity to interference  becomes. This is particularly important when used in vehicles, since malfunctions are often triggered here by electromagnetic interference become.

In a development of the invention, the electronic module has a Evaluation circuit for the output signals of the Hall element and / or a control circuit for generating control signals for the Actuator on. This increases the compact design, since the Control circuit and the evaluation circuit in the electronic Module is integrated. It is also advantageous that a Further cabling can be omitted because the electronic module with its evaluation circuit and its control circuit in spatial Proximity to both the movable element and the actuator can be arranged. This results in a drive device with Integrated actuator and integrated sensors, with this Drive device only one wiring for the power supply and if necessary for further signals with which the actuator of to be controlled externally, must be relocated.

Another advantage for using the electronic component within the drive device as well as for the integration of the Evaluation circuit and / or the control circuit in the electronic module can be seen in the fact that the connection between the Hall signal delivering the output signal depending on the position Element and the evaluation circuit and the connection between the Control circuit and the actuator can be kept extremely short can, so that measures to prevent radiation interference radiation would be required can be omitted. This eliminates not only the shield against electromagnetic interference,  but it also increases the reliability of the whole Drive device.

In a development of the invention, the electronic module is on one Printed circuit board, which is designed in particular as a flexible printed circuit board, arranged, the circuit board in a housing of Drive device is used.

This leads to a high degree of ease of installation, since on the one hand the Printed circuit board at least with the electronic components and if necessary, further cabling and additional components in a first step can be pre-assembled, on the other hand in the Housing already the movable element, the actuator and others Functional elements of the drive device can be used, so that after this insertion only the circuit board with the electronic module must be assembled and thus the assembly of the Drive device is ended. This assembly process is essential easier because there is no exact assignment of the movable element the position detection device must take place, however it must be ensured that the electronic component with its Hall Element close to the magnetic element attached to the movable Element is attached, is arranged. The circuit board in the housing can be an independent component, whereas it is also conceivable that the circuit board is first inserted into a housing cover and then on the housing is put on or an integral part of the Housing cover is. Such a production would be conceivable that first the circuit board with the electronic component is manufactured and then at least these two components with plastic in the Shape of the housing cover are surrounded (molded), so that both the printed circuit board as well as the electronic component with its Hall element  lie completely protected under a plastic layer. At the manufacture of such a housing cover, which is also the housing itself can do it Connection means such as plugs or sockets or the like with be provided. For example, the connection between a To implement the connector and the electronic module, it must be not necessarily around a printed circuit board with attached conductor tracks act, so that instead also in the plastic housing cover also only the conductor tracks, for example in the form of stamped Conductor tracks, can be realized. A flexible circuit board is can be accommodated particularly well with complex designed housings and particularly advantageous in applications involving vibrations and Are exposed to vibrations because they are better from a flexible than from on a rigid circuit board.

Hybrid modules or so-called Lead frames available. A hybrid module is an electronic circuit that has multiple electronic components (Resistors, capacitors, processors, sensors) includes. This can already be wired for a specific application and must be connected and only needs to be inserted into the housing and with its periphery (especially a power supply) become.

A lead frame is to be understood as a component that initially has one electrically non-conductive carrier, in particular made of plastic. This carrier is designed as a largely flat surface, can but bent to adapt to the installation location, kinked or otherwise suitably shaped. In the carrier are electrically conductive Areas, especially tracks, are inserted, for example, from  Sheet metal stampings exist. A possible creation of a lead frame is that the sheet metal stampings are placed in a mold and with Overmoulded plastic. In the places where there is electrical component located on the carrier, are the relevant ones electrically conductive areas led to the outside and with the contacted the relevant component. Plugs or the like can also be formed in one piece with the carrier or as a separate component can also be contacted. So here also stands after the Assembly of the lead frame an electronic module is available, the functionality before installation in the housing can be checked. Thus, only functional building blocks in the housing installed so that after completion of the entire Drive device a possible source of error is excluded.

In a development of the invention, the magnetic element is in one on one Shaft of the movable element attached to the magnetic element holder arranged. This has the advantage of simple assembly, so that on the Shaft only the magnetic element using the magnetic element holder must be attached, with other mounting options (such as gluing) are conceivable. The use of the Magnetic element holder also has the advantage that by means of this magnetic element holder tolerances, especially in axial direction, can be compensated. In addition, one and the same Magnet, especially a permanent magnet, via this magnetic element Holder on different shafts or other movable Elements that have different geometric shapes become. Conversely, it is of course also conceivable that one and same movable element via the magnetic element holder different magnets can be used.  

As already described at the beginning, is a particularly advantageous one Application of the device according to the invention in a Locking device, in particular for a vehicle, given here harsh operating conditions prevail that by means of the invention Using a Hall element can be eliminated. Even if this area of application is considered to be particularly preferred still pointed out that the invention is not based on this Area of application is limited and other applications of Drive device according to the invention, without the inventive concept to leave are conceivable.

The use of the drive device according to the invention in a Locking device is described below and with reference to the figures explained.

Show it:

Fig. 1 shows the basic structure of a locking device,

Fig. 2 shows the arrangement of the elements shown in Fig. 1 in a housing,

Fig. 3 shows a detail from Fig. 2, relating to the position detection device.

Fig. 1 shows an electrically actuated locking device with an actuator, which is designed as an electric motor 1 . A worm wheel 3 is seated on a shaft 2 of the electric motor 1 , a transmission element designed as a control disk 4 being driven by the electric motor 1 . An outer periphery 5 of the control disk 4 is provided with teeth (not shown in FIG. 1) which mesh with the worm wheel 3 and thus form a reduction gear. At least one side of the control disk 4 has inner elevations 6 and outer elevations 7 , which form an intermediate region. The inner and outer elevations 6 , 7 form a contour for setting various functions of the locking device, as will be described later.

The control disk 4 is rotatably mounted on a shaft 9 . Reference number 10 denotes a first lever, the end of which the control disk 4 is assigned carries a pin 11 which projects into the intermediate region 8 and can come into contact with the contours of the inner elevations 6 and outer elevations 7 . Furthermore, a second lever 12 is shown in FIG. 1, which is mounted with the first lever 10 on a common shaft 13 and can be adjusted independently of the first lever 10 by means of internal elevations and external elevations on the other side of the control disk 4 . At this point it should be mentioned that with the embodiment shown in Fig. 1, the actuation of the inside door handle and the outside door handle can be transferred to lock elements such as pawl / rotary latch depending on the positions of the levers 10 and 12 . It is also conceivable to assign a separate handle (such as inside door handle) to its own electric motor 1 with its own control disk 4 and internal elevations 6 and external elevations 7 on only one side and also only a single lever. Since the design of the lock elements does not affect the design of the actuator, an illustration has been omitted. For the sake of clarity, it should be mentioned that a handle is connected to a further lever via Bowden cables, this further lever being actuatable, for example, by the first lever 10 . The further lever acts on lock elements, such as on the pawl interacting with a rotary latch. In its one position, the first lever 10 then causes the further lever to act on the pawl when the handle is actuated, while in its further position the first lever 10 acts on the further lever in such a way that the actuation of the handle does not affect the pawl can act (idle stroke).

This embodiment shown in Fig. 1 thus allows an extremely flat design, which enables all functions of an electrically operated locking device, such as "unlocking", "(central) locking" and "theft protection" (possibly also "child protection"). By appropriate control of the electric motor 1 and the movement of the levers 10 and 12 depending on the contours of the control disc 4 , the lock functions for two handles (such as inside door and outside handle) are realized with only one actuator (electric motor 1 ).

FIG. 2 shows the arrangement of the elements shown in FIG. 1 in a housing 14 . When looking at FIG. 2, this housing 14 is open at the top and is sealed off by a housing cover 15 . For this purpose, a seal, not shown and designated, is provided all around at the connection point between the housing 14 and the housing cover 15 , so that the elements and further elements shown in FIG. 1 and housed in the housing 14 , covered by the housing cover 15 , are moisture and dust-tight are.

A printed circuit board 16 is inserted into the housing 14 , for which purpose corresponding means (such as pins or the like) are provided either on the housing 14 or on the housing cover 15 or on both in order to hold the printed circuit board 16 . For example, the printed circuit board 16 is inserted into corresponding cutouts or the printed circuit board 16 has bores with which it is guided via pins in the housing 14 , with corresponding counter pins being provided in the housing cover 15 which fix the printed circuit board 16 in its position.

The circuit board 16 carries in the area of the movable element, the position of which is to be detected (here the shaft 9 of the control disk 4 ), an electronic component 17 which is electrically connected to the circuit board 16 and its conductor tracks, not shown, via flags. The electronic component 17 can optionally also be mechanically fixed on the printed circuit board 16 . At the end facing the electronic module 17 , the shaft 9 carries a magnetic element 18 , so that a rotation of the shaft 9 also causes a rotation of the magnetic element 18 with its north and south poles, this rotation being detected and evaluated by the electronic module 17 . This detection and evaluation is now described below.

FIG. 3 shows a detailed view of the electronic component 17 and the magnetic element 18 . A Hall element 19 , which reacts to the rotation of the magnetic element 18 , is also arranged in the electronic module 17 , in which an evaluation circuit, which is not designated, is accommodated. The magnetic element 18 is a permanent magnet with a north pole (N) and a south pole (S). By rotating the magnetic element 18 , the current flow in the Hall element 19 is changed and a so-called Hall voltage is generated, so that this Hall element 19 as an output signal is a digital signal or a continuous signal (signal sequences) with several rotations of the magnetic element 18 delivers. This output signal of the Hall element 19 is evaluated by the evaluation circuit, and this can be done, for example, by counting the output pulses of the Hall element 19 . This evaluated output signal can then be used in a control signal for the actuator (electric motor 1 ), the electric motor 1 being controlled, for example, until a further position is reached. If this position has been recognized, the electric motor 1 is switched off. Pre-braking for the electric motor 1 can also be realized by means of the evaluation circuit and control circuit integrated in the electronic module 17 , so that when a pre-position to a certain position has been detected, the control for the electric motor 1 can be reduced so that the electric motor 1 is not only switched off when its predetermined position is reached, but is reached slowly and overshoot is prevented. In this way, complex control of the control for the electric motor 1 to reach its position can be omitted.

A magnetic element holder 20 , which receives the magnetic element 18 , is also placed on the shaft 9 . The magnetic element holder 20 , for example made of plastic, connects the magnetic element 18 to the end of the shaft 9 by means of a clamping action, wherein an axial displacement of the magnetic element 18 in the direction of the Hall element 19 or away from it is possible in order to axially adjust the position of the Hall element 19 to allow the magnetic element 18 for tolerance compensation. In addition, the spaced arrangement of the magnetic element 18 to the end of the shaft 9 largely prevents magnetization of the shaft 9 made of magnetic material, which could lead to undesirable effects.

FIG. 2 also shows that both the electronic component 17 and the magnetic element 18 are arranged in the housing 14 with the housing cover 15 , protected from external influences. If such a protected arrangement is not possible due to the geometric conditions or the installation space, a protective housing can also be provided around the magnetic element 18 and the electronic module 17 . An arrangement would also be conceivable in which the circuit board 16 in FIG. 2 has a recess into which the magnetic element 18 projects and then the electronic component 17 is arranged above the circuit board 16 when viewing FIG. 2. This leads to a further advantageous reduction in installation space.

At this point, the basic mode of operation of a Hall element and its evaluation will be briefly described. A longitudinal current 1 is impressed on the Hall element. A magnet which can be actuated by a movable actuating element or which is fixedly arranged thereon generates a magnetic field B which acts on the Hall element. The so-called Hall voltage UH which arises from the Hall element due to the approach or removal of the magnetic field B of the magnet is taken off at the Hall element and fed to an evaluation unit. The evaluation unit has an external voltage supply, which it receives via corresponding lines (for example voltage line and ground line). Furthermore, a signal line is provided so that the evaluated Hall voltage UH can be made available for further processing, for example via the signal line and the ground line. This is a so-called intelligent evaluation unit that provides an already prepared output signal. A current source, in particular in the evaluation unit, is provided for generating the impressed longitudinal current 1 .

Reference list

1

Electric motor

2nd

wave

3rd

Worm wheel

4th

Control disc

5

Outer circumference

6

Internal surveys

7

External surveys

8th

Intermediate area

9

wave

10th

first lever

11

Cones

12th

second lever

13

common wave

14

casing

15

Housing cover

16

Circuit board

17th

electronic component

18th

Magnetic element

19th

Hall element

20th

Magnetic element holder

Claims (12)

1. Drive device with an actuator for driving a movable element and a position detection device for detecting the position of the movable element, characterized in that the position detection device is a magnetic element ( 18 ) attached to the movable element and a Hall arranged in the vicinity of the magnetic element ( 18 ) - Element ( 19 ), the Hall element ( 19 ) being integrated in an electronic module ( 17 ). 2. Drive device according to claim 1, characterized in that the electronic module ( 17 ) is designed as an ASIC. 3. Drive device according to claim 1 or 2, characterized in that the electronic module ( 17 ) has an evaluation circuit for the output signals of the Hall element ( 19 ) and / or a control circuit for generating control signals for the actuator. 4. Drive device according to one of claims 1 to 3, characterized in that the electronic module ( 17 ) on a circuit board ( 16 ), in particular a flexible circuit board, is arranged, the circuit board ( 16 ) in a housing ( 14 ) of the drive device is inserted. 5. Drive device according to one of claims 1 to 3, characterized in that the electronic module ( 17 ) is designed as a hybrid module, the hybrid module being inserted in a housing ( 14 ) of the drive device. 6. Drive device according to one of claims 1 to 3, characterized in that the electronic module ( 17 ) is arranged on a lead frame, the lead frame being inserted in a housing ( 14 ) of the drive device. 7. Drive device according to one of claims 1 to 3, characterized in that the electronic component ( 17 ) is arranged on a printed circuit board ( 16 ), the printed circuit board in a housing cover ( 15 ) for a housing ( 14 ) of the drive device or part of the housing cover ( 15 ). 8. Drive device according to one of the preceding claims, characterized in that the magnetic element ( 18 ) in a fixed to a shaft ( 9 ) of the movable element magnetic element holder ( 20 ) is arranged. 9. Drive device according to one of the preceding claims, characterized in that the drive device as Locking device, in particular for a vehicle, is formed.   10. Drive device according to claim 8 or 9, characterized in that the movable element is a control disc ( 4 ) for setting functional positions of the locking device. 11. Drive device according to one of the preceding claims, characterized in that the actuator is designed as an electric motor ( 1 ). 12. Drive device according to one of the preceding claims, characterized in that at least the magnetic element ( 18 ) in a magnetic housing ( 18 ) surrounding protective housing, in particular the housing ( 4 ), is housed.