DE102011012688A1 - Door handle unit for a vehicle - Google Patents

Abstract

A door handle unit (2) for a vehicle door is specified. The door handle unit (2) comprises a door handle (1) with a handle body (7) and with a capacitive sensor device (20) for detecting an approach of a hand of a vehicle user. The sensor device (20) comprises a first sensor electrode (21) for detecting an unlocking signal, a second sensor electrode (22) for detecting a locking signal, and evaluation electronics (24). The first sensor electrode (21) is arranged on a rear side of the grip body (7), while the second sensor electrode (22) is arranged on a front side of the grip body (7).

Description

The invention relates to a door handle unit for a vehicle.

Door handles, especially outside door handles of high-quality motor vehicles are often provided with electronic components, in particular with capacitive sensors or buttons. Such capacitive sensors are used, for example, in a system for keyless vehicle access (also referred to as "keyless go", "keyless entry", etc.) to detect an approach of a hand of a vehicle user and in response to the detected proximity signal the vehicle to unlock.

A capacitive sensor normally comprises a so-called sensor electrode, which forms a first electrode of a capacitor. As a counter electrode of the capacitor usually serves a penetrating into the detection range of the sensor grounded object z. B. a human body part. When the object (in this case the hand of a vehicle user) approaches the sensor, the capacitance of the capacitor formed between the sensor electrode and the counterelectrode changes. The capacitance change is determined directly or indirectly by means of an evaluation electronics and compared with a predetermined triggering criterion, from which the evaluation of the presence or absence of an object in the detection area, and optionally also on the distance of the object to the sensor closes.

The invention has for its object to provide a door handle unit for a vehicle, which is particularly well suited for use for a keyless entry system. In particular, the door handle unit is to ensure a fail-safe function of the keyless entry system. Furthermore, the door handle unit should be stable and wear-susceptible, but at the same time simple and efficient to produce.

With regard to a door handle unit, this object is achieved according to the invention by the features of claim 1. The door handle unit according to the invention comprises a door handle, which is essentially formed by a handle body. Furthermore, the door handle unit comprises a capacitive sensor device for detecting the approach of a hand of a vehicle user. The sensor device comprises a first sensor electrode for the detection of an unlocking signal and a second sensor electrode for the detection of a locking signal. The first sensor electrode is arranged in the vicinity of a rear side of the grip body, which faces the vehicle door positively in the intended installation. The rear sensor electrode serves primarily to detect the approach of the hand when it engages around the grip body. The rearward sensor electrode preferably extends over a large part of the longitudinal extension of the grip body.

The second sensor electrode is preferably arranged in the vicinity of a front side of the handle body, which faces away from the vehicle door in the mounting position. By means of this sensor electrode, the approach of a finger is detected as a locking signal. In order to display a locking request, the vehicle user deletes, in particular with his finger, the area occupied by the sensor electrode. The second sensor electrode has, in an expedient embodiment, a substantially smaller extent than the first sensor electrode. However, it is also conceivable to make the first and second sensor electrodes approximately the same size.

Furthermore, the sensor device comprises evaluation electronics which evaluate the signals detected by the sensor electrodes and transmit them to a door control unit. Depending on the sensor signal causes the door control unit according to a locking or unlocking a door lock of the associated vehicle door or as part of a central locking the locking or unlocking of all vehicle doors.

In order to largely exclude mutual interference of the sensor electrodes, the sensor electrodes are expediently interposed by a shield electrode which electrically shields the two electrodes from one another. In a particularly simple embodiment, each sensor electrode serves as a shield for the respective other sensor electrode.

In a particularly rationally producible and expedient embodiment of the handle body is formed as a plastic injection molded part. The electrodes are expediently made in one piece with each subsequent electrical supply lines as metal stampings. These stampings are preferably embedded in the handle body by being molded directly with the plastic material of the handle body.

Instead of punched parts, layers of an electrically conductive lacquer can also be used to form the electrodes and the associated supply lines. Furthermore, the electrodes and leads can also be made of an electrically conductive plastic. The advantage of this embodiment lies in particular in the fact that the entire door handle including the handle body and the electrodes and leads embedded therein in a (two-component) injection molding process can be produced.

According to a further alternative, the sensor electrodes are produced in so-called MID (Molded Interconnect Device) technology. In this case, one or more interconnects are introduced or introduced onto an injection molded circuit carrier made of plastic. The Aufbw. Introducing the conductor tracks is effected for example by printing or spraying of the circuit carrier with a conductive fluid, laser structuring, hot stamping or flame spraying (z. B. Flamecon ^® process).

In principle, flexible conductors, in particular stranded conductors, can also be used as supply lines.

Also in terms of rational production, at least two electrodes are formed with the associated leads from a common, contiguous metal stamped grid whose individual strands are fixed in position relative to each other by at least one plastic preform and then cut free from each other for mutual electrical insulation. Before the encapsulation of the stamped grid with the pre-molded part, the stamped grid is preferably bent into a three-dimensional shape, in which the individual strands of the stamped grid correspond to the desired position of the electrodes and supply lines with respect to their relative position.

In a particularly compact embodiment of the invention, the transmitter is integrated in the handle body. To produce an electrically conductive connection between the evaluation electronics and the electrodes, the evaluation electronics are preferably pressed onto contact ends of the associated supply lines. The press-contacting of the evaluation with the leads has - for example, compared to a solder or adhesive joint - the advantage that it is very stable and resistant to changing loads (especially bending and torsional stresses) and micro-movements, as in the interior of a vehicle door handle in Operation often occur.

In an alternative embodiment of the invention, the transmitter is arranged outside the door handle. The evaluation is in this case provided in particular for installation in the interior of a vehicle door. The griffexterne arrangement of the evaluation, in particular in the door interior, in particular has the advantages that the sensitive evaluation electronics on the one hand better protected against weathering than in the handle body. Furthermore, the outsourced from the door handle transmitter is also not exposed to the door handle regularly occurring mechanical stresses. In a particularly rational training, the transmitter is integrated in particular in the door control unit, which causes the automatic locking and unlocking of the vehicle door. The door control unit and the evaluation are preferably constructed on one and the same circuit hardware, this hardware is formed in an appropriate training essentially by a microcontroller. The functionality of the door control unit and the evaluation electronics are implemented by components of a firmware associated with the microcontroller software.

In order to avoid disturbances and distortions of the signals supplied by the sensor electrodes by parasitic capacitances and electrical interference fields as far as possible, the feed lines interposed between the sensor electrodes and the evaluation electronics are electrically shielded in an expedient embodiment of the invention. The shielding of the leads is provided in particular in embodiments of the door handle unit, in which the transmitter is outsourced from the door handle. Namely, such embodiments necessarily require long supply lines, in which the influence of capacitances and electrical interference fields has a particularly significant effect. When integrated into the door handle evaluation the above-mentioned interference effects due to the only short leads from house only a relatively small influence. Shielded supply lines can, however, also be advantageously used within the scope of the invention for achieving improved measuring accuracy.

The shield conductor of the shielded line can in principle be laid by the evaluation electronics or a separate connection to ground potential. As is known, however, the shielding conductor is set by the evaluation electronics or a separate control unit to an electrical potential which is equal to the potential of the shielded supply line or at least deviates comparatively little from the latter. The potential of the shield conductor can be analog, d. H. amount continuously controlled. In an embodiment that is particularly easy to implement, however, the potential of the shielding conductor is switched digitally between two values ("high" / "low"), in particular "high" being the operating potential of the evaluation electronics (eg 5 volts) and "low" being the ground potential (0 volts). In this case, the shielding conductor is preferably set to the "high" potential when the associated sensor electrode is charged, and to the "low" potential when the sensor electrode is discharged. For potential control of the shielding conductor, this is expediently connected to a digital output of the evaluation electronics.

In a mounting-friendly embodiment, the door handle unit comprises a contact device for contacting the handle-internal electrical and electronic components, in particular the electrodes and / or the evaluation (if it is integrated in the door handle), with external electronic or electronic components, such as the door control unit and / or the transmitter (if this is outsourced from the door handle). The contact unit is formed in particular by a connector with a handle-side contact element and a door-side contact element.

The leads that connect this contact unit inside the handle with the electrodes and / or the optionally grip integrated evaluation, are also formed by stampings, in particular strands of a punched grid expediently.

In the course of a particularly advantageous method for producing the door handle unit, a stamped grid made of sheet metal is punched out according to the invention, which has a plurality of wire strands, which are at first connected via at least one connecting bridge, for forming in each case one electrode and / or one feed line. The stamped grid is - if necessary - bent into a three-dimensional shape in which the position of the individual strands of wire corresponds to the desired relative position of the electrodes and leads. The strands of wire are then fixed in position relative to each other by extrusion coating with at least one plastic preform in their relative position. Subsequently, the electrical insulation strands are cut from each other by removing the or each connecting bridge. The various conductor strands are thus still held together by the at least one pre-molded part, but electrically separated from each other. The bundle of conductor strands held by the at least one pre-sprayed section is then encapsulated with a plastic material to form the grip body. The conductor strands forming the electrodes and leads in the finished state of the door handle are embedded in the material of the grip body during encapsulation. Optimally, before or simultaneously with the spraying of the actual handle body, a support grid, in particular in honeycomb form, injected, which improves the stability of the door handle. For the support grid in this case preferably a comparatively hard plastic is selected, while the handle body is injected from a contrast softer plastic. The support grid is molded in order to achieve a particularly high stability, in particular to the conductor bundle formed from the electrodes and leads.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

1 in side view of a door (outside) handle a door handle unit for a motor vehicle, wherein in the door handle a capacitive sensor unit with two sensor electrodes and a transmitter is integrated,

2 in plan view of a front of the door handle according to 1 , and

3 in a schematic side view of the door handle in a further embodiment in which the transmitter is outsourced from the door handle.

Corresponding parts are always provided in all figures with the same reference numerals.

1 shows a door (outside) handle 1 a door handle unit 2 for a vehicle door, here for a side door of a motor vehicle. The illustrated door handle 1 is in a side view with a view of an intended installation situation upwardly facing top 3 shown. Accordingly, the opposite bottom of the door handle 1 not visible in the illustration. A designated the vehicle door facing side is as the back 5 the door handle 1 designated, while a side facing away from the door as a front page 6 is designated.

The door handle 1 includes an elongated, slightly curved (plastic) handle body 7 , which is aligned approximately parallel to the vehicle door. The intended purpose of the front of the vehicle facing the end of the door handle 1 is as a front longitudinal end 8th designated, while the opposite end as a rear longitudinal end 9 is designated.

All direction-determining terms refer to these definitions and in the following are independent of the actual position of the door handle 1 used in the room.

At the rear longitudinal end 9 protrudes a stop hook on the back 10 from the handle body 7 off, at the front longitudinal end 8th also protrudes back a bearing angle 11 from the handle body 7 from. Both the stop hook 10 as well as the bearing angle 11 serve in a conventional manner for pivotal mounting of the door handle 1 in a door handle receptacle, not shown here, in the vehicle door. By pivotal movement of the door handle 1 a lock of the vehicle door is actuated.

In the handle body 7 the door handle 1 is a sensor device 20 integrated. The sensor device 20 serves as described above to detect the approach of a hand of a vehicle user to the door handle and possibly a closing signal or Output signal to output the door lock operating door control unit.

The sensor device 20 comprises a first, rear-side capacitive sensor electrode 21 , a second sensor electrode arranged at the front 22 , as well as a third, between the two sensor electrodes 21 . 22 arranged shield electrode 23 , Each of the electrodes 21 . 22 . 23 is essentially formed by a conductor made of copper. How out 2 can be seen, is the backside sensor electrode 21 formed by a narrow, annular closed conductor track structure, which is approximately centrally in the handle body 7 is arranged, and spread over a large proportion of the length of the handle body 7 expands. The sensor electrode 22 has a substantially small surface area than the sensor electrode 21 , It is formed by an approximately square conductor surface and at the rear longitudinal end 9 of the handle body 7 arranged. The sensor electrodes 21 and 22 are arranged such that they face in the direction of the front 6 do not overlap. In the 2 for reasons of clarity not shown) shield electrode 23 is preferably formed flat and in particular in one at the rear end 9 adjacent area of the handle body the sensor electrodes 21 . 22 interposed.

The sensor device 20 further includes an evaluation 24 , which are in the area of the front longitudinal end 8th in the grip body 7 is integrated. The evaluation electronics 24 includes a rigid circuit board 25 with soldered in the usual way electronic components. Each of the sensor electrodes 21 . 22 . 23 is in each case via an assigned supply line 27 with the transmitter 24 contacted. The circuit board 25 the transmitter 24 this is on a contact end 26 the respective supply line 27 pressed.

On the other hand, the circuit board 25 , again by press contact, by means of further supply lines 28 with a grip-side contact element 30 a contact device 31 connected. The contact element 30 is at the front longitudinal end 8th a parallel leg 32 of the bearing angle 11 rigidly connected to this.

In the embodiment illustrated here, the grip-side contact element comprises 30 a connector housing 33 in which tinned connection pins are received, which correspond to form an electrical connector with associated sockets of a door-side contact element. The door-side contact element is in turn connected to a built-in door in the vehicle door control unit 34 ( 3 ).

In the plan view according to 2 on the handle body shown transparent 7 is also evident that the handle body 7 inside a three-dimensional support grid in the form of a honeycomb structure 40 having. This honeycomb structure 40 serves on the one hand to increase the torsional stiffness of the handle body 7 , On the other hand, the honeycomb structure fixes 40 the electrodes 21 . 22 . 23 in terms of their relative position to each other. In this regard, it should be noted that the electrodes 21 . 22 . 23 just for the sake of clarity than on the honeycomb structure 40 are shown lying on top. In fact, the sensor electrodes 21 . 22 . 23 however, from the honeycomb structure 40 enclosed.

• – die Sensorelektrode 21 mit der zugehörigen Zuleitung 27,
• – die Sensorelektrode 22 mit der zugehörigen Zuleitung 27,
• – die Schirmelektrode 23 mit der zugehörigen Zuleitung 27, sowie
• – jeweils eine der Zuleitungen 28

bilden, noch durch die Vorspritzlinge in ihrer Relativlage zueinander gehalten werden, wohingegen die einzelnen Leiterstränge aber elektrisch voneinander getrennt sind.For the production of the door handle 1 According to the embodiment shown here, first the electrodes 21 . 22 . 23 , as well as the supply lines 27 . 28 in the form of elongated tracks made of a stamped grid. The punched out sensor electrodes 21 . 22 . 23 , as well as the supply lines 27 . 28 are then bent into their three-dimensional shape and prefixed by pre-molded parts. Thereafter, remaining connection bridges between the individual conductor strands of the stamped grid are separated, so that the conductor strands, the

• - the sensor electrode 21 with the associated supply line 27 .
• - the sensor electrode 22 with the associated supply line 27 .
• - the shield electrode 23 with the associated supply line 27 , such as
• - one of each of the supply lines 28

form, are still held by the preforms in their relative position to each other, whereas the individual conductor strands are electrically separated from each other.

Subsequently, the prefixed conductor strands with the honeycomb structure 40 molded. The prefixed conductor strands with the molded honeycomb structure 40 formed unit is then finally with the handle body 7 molded.

In 3 is a second embodiment of the door handle 1 shown. In this second embodiment, the door handle comprises 1 a rear-mounted handle shell 50 , which is made of plastic as an injection molded part. Furthermore, the door handle includes 1 a lid 51 , which may also be made of plastic or sheet metal, and in the assembled state on the handle shell 50 is snapped. Between the handle shell 50 and the lid 51 cavities are formed, each as a receptacle 52 for one of the sensor electrodes 21 . 22 serves. The sensor electrodes 21 . 22 are each formed in this embodiment by the outer conductor of a flexible coaxial cable. Optionally, in this embodiment, in addition to the sensor electrodes, also the shield electrode 23 intended. The shield electrode 23 can in particular by a sensor electrodes 21 . 22 be formed intermediate metal foil.

The sensor electrodes 21 . 22 are preferred in the respective recording 52 glued. In addition, the sensor electrodes 21 . 22 with an elastic band 53 made of sponge rubber, which is between the sensor electrodes 21 . 22 and the lid 51 rests, elastic in the recording 52 fixed.

The sensor electrodes 21 . 22 are about the here flexibly designed supply lines 27 directly with the contacting device 31 connected. Door side is the contact device 31 by means of a shielded cable 60 with the transmitter 24 connected.

The evaluation electronics 24 is here in contrast to the first embodiment is not in the handle body 7 but in the door control unit 34 integrated, which is installed in the weather-protected interior of the vehicle door. To the door control unit 34 is also a leader 61 connected, which leads to an access control unit (keyless control), not shown here, which checks the authorization of the vehicle user by wireless communication with a - for example integrated in a vehicle key - identification transponder and releases the door unlocking when properly identifying the vehicle user.

LIST OF REFERENCE NUMBERS

1

Door (the outside) grabbed

2

The door handle unit

3

top

5

back

6

front

7

handle

8th

(front) longitudinal end

9

(rear) longitudinal end

10

stop hook

11

bearing angle

20

sensor device

21

sensor electrode

22

sensor electrode

23

sensor electrode

24

evaluation

25

circuit board

26

Contact end

27

supply

28

supply

30

contact element

31

contactor

32

parallel leg

33

plug housing

34

Door control unit

40

honeycomb structure

50

grip

51

cover

52

admission

53

tape

60

management

61

management

Claims (10)

Door handle unit ( 2 ) for a vehicle door, with a handle body ( 7 ) comprehensive door handle ( 1 ) and with a capacitive sensor device ( 20 ) for detecting an approach of a hand of a vehicle user, wherein the sensor device ( 20 ) a first sensor electrode ( 21 ) for detecting an unlocking signal, a second sensor electrode ( 22 ) for detecting a locking signal, as well as evaluation electronics ( 24 ), wherein the first sensor electrode ( 21 ) on a rear side of the handle body ( 7 ), and wherein the second sensor electrode ( 22 ) on a front side of the handle body ( 7 ) is arranged. Door handle unit ( 2 ) according to claim 1, wherein between the first sensor electrode ( 21 ) and the second sensor electrode ( 22 ) a shield electrode ( 23 ) is arranged. Door handle unit ( 2 ) according to claim 1 or 2, wherein the handle body ( 7 ) is formed as a plastic injection-molded part, and wherein the electrodes ( 21 . 22 ) in one piece with each subsequent electrical supply lines ( 27 ) are manufactured as metal stampings, which with the plastic material of the handle body ( 7 ) are sprayed over. Door handle unit ( 2 ) according to one of claims 1 to 3, wherein at least two electrodes ( 21 . 22 . 23 ) with the associated supply lines ( 27 ) are formed from a common, contiguous metal stamped grid whose individual strands of wire, optionally after a bending process downstream of the punching, are fixed in position relative to each other by at least one plastic preform and then cut free from each other for mutual electrical insulation. Door handle unit ( 2 ) according to claim 3 or 4, wherein the evaluation electronics ( 24 ) in the handle body ( 7 ) and the evaluation electronics ( 24 ) on contact persons ( 26 ) of the sensor electrodes ( 21 . 22 ) associated supply lines ( 27 ) is pressed. Door handle unit ( 2 ) according to one of claims 1 to 4, wherein the evaluation electronics ( 24 ) from the door handle ( 1 ) is outsourced. Door handle unit ( 2 ) according to claim 6, wherein the evaluation electronics ( 24 ) in an automatic Locking and unlocking the vehicle door provided door control unit ( 34 ) is integrated. Door handle unit ( 2 ) according to one of claims 1 to 7, wherein the sensor electrodes ( 21 . 22 ) and the evaluation electronics ( 24 ) via a shielded supply line ( 60 ) are interconnected. Door handle unit ( 2 ) according to one of claims 1 to 8, with a contact device ( 31 ) for contacting the electrodes ( 21 . 22 . 23 ) and / or the optionally internally arranged evaluation electronics ( 24 ) with an externally arranged electrical or electronic component ( 24 ; 34 ), as well as with at least one electrical supply line ( 28 ), which the contact device ( 31 ) within the handle with an electrode ( 21 . 22 . 23 ) or the evaluation electronics ( 24 ), this supply line ( 28 ) formed from a metal stamped part and with the plastic material of the handle body ( 7 ) is sprayed over. Method for producing a door handle unit ( 2 ) according to one of claims 1 to 9, in which a stamped grid is punched out of sheet metal, which first comprises a plurality of interconnected via at least one connecting bridge strands to form in each case an electrode ( 21 . 22 . 23 ) and / or a supply line ( 27 . 28 ), in which the lead frame is optionally bent into a three-dimensional shape, wherein the wire strands are fixed in position relative to each other by encapsulation with at least one plastic preform in their relative position to each other, wherein the strands of wire are mutually cut by removing the or each connecting bridge, and at in which the cable strands held by the at least one pre-molded part form the grip body ( 7 ) are overmoulded with a plastic material.

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