WO2017140806A1

WO2017140806A1 - Measuring electrode for a capacitive proximity sensor of a motor vehicle

Info

Publication number: WO2017140806A1
Application number: PCT/EP2017/053544
Authority: WO
Inventors: Florian Pirchheim; Bernd Herthan
Original assignee: Brose Fahrzeugteile Gmbh & Co. Kg, Bamberg
Priority date: 2016-02-16
Filing date: 2017-02-16
Publication date: 2017-08-24
Also published as: DE102016102667A1

Abstract

The invention relates to a measuring electrode for a capacitive proximity sensor (2) of a motor vehicle, comprising a conductor structure (4) and a flat support structure (5) for receiving the conductor structure (4). According to the invention, the conductor structure (4) has at least one electrically conductive yarn (6) which is applied to the support structure (5) in the form of a plurality of stitches (7).

Description

Measuring electrode for a capacitive proximity sensor

of a motor vehicle

The invention relates to a measuring electrode for a capacitive proximity sensor of a motor vehicle according to the preamble of claim 1, a capacitive proximity sensor with such a measuring electrode according to claim 12, a body component of a motor vehicle, to which such a proximity sensor is attached, according to claim 13 and a method for manufacturing Such a measuring electrode according to claim 14.

The capacitive proximity sensor in question can be used for very different fields of application. In the present case, sensor-based acquisition of operating events is in the foreground. An operator event to be detected may be, for example, the approach of a person to the motor vehicle, a predetermined foot movement of a person or the like. The sensor-based detection of such operating events triggers appropriate control technology reactions, such as the motorized opening of the tailgate of the motor vehicle.

The known measuring electrode (DE 10 2013 110 866 AI), from which the invention proceeds, is associated with a capacitive proximity sensor of a motor vehicle. The measuring electrode is formed by at least one flat conductor, which is designed for example as an insulated copper strip. Such a flat conductor is usually made up of a continuous material. Although this is production-wise effective, it leads to restrictions in the design of the measuring electrode. A first limitation stems from the fact that the shape of the flat conductor of the known measuring electrode is fixed. As a result, more copper material is generally used than is technically necessary. A second limitation is that for the contacting the usually comparatively wide flat conductor special plug must be provided, which lead to correspondingly high material and assembly costs.

The invention is based on the problem of designing and further developing the known measuring electrode such that the flexibility in designing the measuring electrode is increased and at the same time the production costs are reduced. The above problem is solved in a measuring electrode for a capacitive proximity sensor of a motor vehicle by the features of claim 1. Essential is the fundamental consideration that a measuring electrode can be produced by an electrically conductive yarn, which is applied by methods known from sewing technology on a flat support structure. The term "stitching" is always to be understood in the present case and encompasses all methods of joining a yarn with a support structure, which are based on the particular needle-based introduction of stitches into the support structure and the subsequent passage of the yarn through the respective stitches In addition to sewing in the narrower sense, embroidery o. dgl ..

With the proposed sewing of the electrically conductive yarn can be on the support structure produce a conductor pattern of almost any shape. At the same time, the sewing of the yarn can be carried out fully automatically, so that mass production of the proposed measuring electrode is readily possible. Specifically, it is proposed that the measuring electrode has a conductor structure and a planar carrier structure for receiving the conductor structure, wherein the conductor structure has at least one electrically conductive yarn which is applied to the carrier structure in a plurality of stitches. By applying the yarn in sections to the support structure, the introduction of the electrically conductive material of the yarn into the support structure can be precisely adjusted. As a result, not only a flexible design of the measuring electrode at low cost is possible, but also a reduction of the use of material of electrically conductive material. In the particularly preferred embodiment according to claim 2, the applied yarn on the support structure defines an electrode surface of the measuring electrode, wherein the distribution of the applied yarn within the electrode surface and the shape of the electrode surface determine the electrical behavior of the measuring electrode with respect to its function as an electrode of a capacitive proximity sensor , Both the storage and the mounting of the support structure has further advantages when the support structure and in particular the measuring electrode is designed as a whole sluggish (claim 5). For example, during assembly, the measuring electrode can be applied exactly to a body component of a motor vehicle which is to carry the measuring electrode, largely independently of the geometry of the body component.

In the further preferred embodiment according to claim 8, the proximity sensor has a measuring control, wherein at least a part of the measuring control is arranged on the support structure and in particular is formed by the conductor structure. Here, in a particularly preferred embodiment, the conductor structure can be used to provide electrical connections to the measurement controller or within the measurement controller.

According to a further teaching according to claim 10, which has independent significance, the capacitive proximity sensor of a motor vehicle, which has a measuring controller and a proposed measuring electrode, is claimed as such. Reference should be made to all explanations of the proposed measuring electrode.

According to another teaching according to claim 13, which also has independent significance, a body component of a motor vehicle, to which a proposed proximity sensor is attached, is claimed as such. Here, too, reference may be made to all the details of the proposed measuring electrode and to the proposed proximity sensor.

According to another teaching according to claim 14, which also has independent significance, a method for producing a proposed measuring electrode is claimed.

It is essential according to the proposed method that the conductive yarn is applied in a plurality of stitches on the support structure. The proposed method is preferably carried out by sewing or embroidery machines, with which a high degree of automation can be achieved. In the particularly preferred embodiment according to claim 15, the application of the conductive yarn is followed by a cutting process, in which the support structure is assembled by cutting to length and / or covering the respective application. Here it is particularly possible that the conductive yarn is applied to an endless support structure, which further favors the mass production of the proposed measuring electrode.

In the following the invention will be explained in more detail with reference to a drawing illustrating only exemplary embodiments. In the drawing shows

Fig. 1, the rear portion of a motor vehicle with a proposal

Body component having a proposed proximity sensor with a proposed measuring electrode,

FIG. 2 shows the bumper-shaped, proposed body component of the motor vehicle according to FIG. 1 in the disassembled state, FIG.

3 a) for a two-part measuring electrode and separate measuring control, b) for a two-part measuring electrode and integrated measuring control, and c) for a measuring electrode applied to the body component and FIG

FIG. 4 shows the body component according to FIG. 2 along the section line IV-IV a) when the measuring electrode is firmly fixed by means of a material loop,

b) when mounting the measuring electrode by means of positive and non-positive and

c) when attaching the measuring electrode by means of Velcro connection.

The measuring electrode 1 for a capacitive proximity sensor 2 can be used for a variety of applications in a motor vehicle application. Depending on the design, it allows the sensory detection of the presence and / or movement of an object or a user. The sensory detection is based on a change in capacitance of the measuring electrode 1 with respect to ground or with respect to a further measuring electrode, which is slightly electronic Here and preferably, the proximity sensor 2 is used to detect an operating event, namely a predetermined foot movement of a user, wherein the sensory detection of the operating event triggers a motorized opening of the tailgate 3 of the motor vehicle. Another exemplary application is collision detection in motor vehicle doors.

A comparison of FIGS. 1 and 2 shows that the measuring electrode 1 has a conductor structure 4 and a flat Tragelstruktur 5 for receiving the conductor structure 4 Alternative embodiments of the embodiment of the measuring electrode 1 shows the illustration of FIG. 3. All statements to the various embodiments for the measuring electrode 3 apply mutatis mutandis.

2 shows that the conductor structure 4 has at least one electrically conductive yarn 6, which is applied in a plurality of stitches 7 on the support structure 5. The conductor structure 4 is sewn onto the support structure 5, wherein the term "stitching", as explained above, is to be interpreted broadly.

The yarn 6 applied to the carrier structure 5 defines an electrode surface 8 of the measuring electrode 1 on the carrier structure 5. In the sectional illustration in the top right-hand corner, the electrode surface 8 defined by the yarn 6 is indicated in dash-dotted line. 2 and so far preferred exemplary embodiment, it is provided that the applied yarn 6 on the support structure 5 defines the electrode surface 8 in that the applied yarn 6 at least partially surrounds the electrode surface 8. Corresponding shows the preferred embodiment of FIG. 3c). In the further preferred embodiments according to FIGS. 3 a), b), it is in each case such that the electrode surface 8 is defined by the fact that the applied yarn 6 at least partially fills the electrode surface 8. Overall, the electrode surface 8 together with the distribution of the yarn 6 within the area significantly defines the electrical behavior of the measuring electrode 1 as an electrode for a capacitive proximity sensor 2.

When sewing the conductor structure 4 on the support structure 5 different types of stitches from the sewing technique can be applied. In general, it is provided that the electrically conductive Gran 6 along at least one seam line 9 is applied in at least one stitch on the support structure 5. In principle, provision may also be made for the type of stitching to change along the measuring electrode. Exemplary stitch types here are the pre-stitch illustrated in FIG. 2, the crossstitch or the lockstitch.

The conductive Gran 6 can be provided in different configurations. In the simplest case, the conductive yarn 6 consists of a single fiber, which is inexpensive and guarantees easy workability. Alternatively, it can be provided that the conductive yarn 6 consists of a plurality of fibers, which is associated with a high degree of robustness against possible cable breaks

Also for the material of the conductive yarn 6, depending on the application, different advantageous variants are conceivable. Here and preferably, the conductive yarn 6 is made of a stainless steel material or a copper material. In the former case, the corrosion resistance is of particular advantage.

The support structure 5 as such is in the illustrated and insofar preferred exemplary embodiments designed as such limp wherein in a particularly preferred embodiment, the applied yarn 6 having measuring electrode 1 is configured as such limp. Thus, the measuring electrode 1 can be flexibly adapted to any shape, such as Fig. 2, 3c) and 4 show.

It is also conceivable, however, for the support structure 5 to be designed to be rigid, which further simplifies the handling of the support structure 5. For example, the support structure 5 may be impregnated to produce the rigid characteristic.

It can best be seen from the illustration according to FIG. 2 that the carrier structure 5 is a textile structure. The textile structure can be any textile structure. The textile structure can be made of a yarn, which is preferably a yarn of a plastic material. This makes it possible to achieve that the resulting support structure 5 is at least to a first approximation water-repellent , Alternatively, the support structure 5 may be configured as a film structure. The film structure here and preferably also consists of a plastic material, in particular polyethylene or the like. In a particularly preferred embodiment, the present carrier structure 5 is a flexible film structure which preferably has a certain mechanical rigidity in order to produce a to ensure good handling.

The designed as a film structure support structure 5 basically allows a waterproof construction of the measuring electrode 1 in total. This can best be achieved by realizing a multi-layered film structure that seals off the conductor structure 4 in a watertight manner. This can be realized, for example, by the fact that the several layers of the film structure are welded together at the edges.

The above water-tightness can alternatively be achieved by immersing the carrier structure 5 together with the conductor structure 4 in a liquefied coating material, in particular in a liquefied polymer. Other ways of sealing are conceivable

Fig. 2 shows that the electrode surface 8 is at least partially elongated there. Specifically, two electrode subareas 8a), 8b) are provided, which are each designed to be elongated. It can further be seen from the illustration according to FIG. 2 that here and preferably the electrode partial surfaces 8a) and 8a) are arranged parallel to one another, in particular next to one another, on the carrier structure 5.

In the preferred exemplary embodiments according to FIG. 3 a), b), it is further the case that the proximity sensor 2 has a measuring controller 11, wherein at least part of the measuring controller 11 is arranged on the carrier structure 5 and is preferably formed by the conductor structure 4. In the exemplary embodiment illustrated in FIG. 3 a, although the measuring controller 11 is arranged on the carrier structure 5, it is formed separately from the conductor structure 4.

According to FIG. 3 b), a particularly compact embodiment results from the fact that at least part of the measuring controller 11 itself is guided by the conductor structure 4 itself. is formed. In the simplest case, it is the case that the measuring controller 11 has at least one electrical connection 12, the conductor structure 4 providing at least part of the at least one electrical connection 12. In this case, the seam lines 9 can be realized similar to conductor tracks of a printed circuit board.

The measuring controller 11 can furthermore have electronic components 13, as can likewise be seen from the illustration according to FIG. 3b). These electronic components 13 may be components of a discrete circuit and / or integrated components. In the exemplary embodiment shown in FIG. 3 b, the contacting of the components 13 takes place at least in part via the conductor structure 4 produced by the electrically conductive yarn 6.

The possibility shown in FIG. 3b) of integrating the measuring controller 11 in a sense into the measuring electrode 1 results in short signal lines, which is fundamentally associated with a high degree of robustness against interference influences.

In this connection, it should be pointed out that the carrier structure 5 is configured as a single layer in the exemplary embodiments shown and preferred so far. In principle, however, it is also conceivable that the carrier structure 5, as indicated above in connection with the film structure, consists of a plurality of layers, on each of which an electrically conductive yarn 6 is applied. Also in this respect can be applied to the different layers of the support structure 5 different interconnects of the electrically conductive yarn 6, as is in turn known for multilayer printed circuit boards

The proximity sensor 2, here the measuring electrode 1, has at least one electrical connection 14, 15, wherein the conductor structure 4 in a particularly preferred embodiment provides at least part of the electrical connection 14, 15. Such an electrical connection 14, 15 further preferably has an electrical connection line 16, 17 and / or at least one electrical contact 18, 19. In the exemplary embodiments illustrated in FIG. 3, it is the case that two connections 14, 15 are provided which are each equipped with a connecting line 16, 17 and a contact 18, 19. The Contacts 18, 19 can be connected, for example by crimping, welding, soldering or the like, electrically to a supply line 20, 21 with little effort. Alternatively, it is also conceivable that the contacts 18, 19 are sewn to a feed line 20, 21.

FIG. 3 shows that completely different measuring electrodes 1 can be realized, depending on the type of application of the electrically conductive yarn 6. In the exemplary embodiment illustrated in FIG. 3a), the measuring electrode 1 is divided into two, as mentioned above, wherein the two partial electrode surfaces 8a, 8b are configured identically.

In the exemplary embodiment shown in FIG. 3b), the measuring electrode 1 is likewise a measuring electrode divided in two, wherein the two electrode partial surfaces 8a, 8b are configured differently. Depending on the position of the respective electrode subarea 8a, 8b in the motor vehicle, different antenna structures may be advantageous, for example in order to optimize the range of the respective measuring range , In particular, it can also be provided here that the electrode surfaces 8 are realized on a plurality of layers of the carrier structure 5 in order to be able to implement an optimum antenna structure.

The proposed measuring electrode 1 is fastened in the mounted state via the support structure 5 to a body component 22, here on a bumper, of the motor vehicle. The body component 22 may be any body component of the motor vehicle. For example, the body component 22 accommodating the measuring electrode 1 may be a tailgate 3, a side door, an engine hood or the like of the motor vehicle mentioned above.

4 shows three preferred options for attaching the measuring electrode 1 to the body component 22. In a particularly preferred embodiment, which is shown in FIG. 4 a), the fastening is a material-locking attachment. In this case, an adhesive layer 23 or a layer of elastic, double-sided adhesive material is preferably arranged between the carrier structure 5 and the body bag 22 Alternatively or additionally, the fastening can be a positive fastening, as shown by way of example in FIG. 4. Here, the support structure has 5 Befestigungsöffhungen 24, protrude through the mounting dome 25 of the body part 22. For fixing the measuring electrode 1 to the fixing domes 25 corresponding clamping rings 26 are clamped to the mounting dome 25. Accordingly, in the attachment shown in Fig. 4 is a mixed form of a positive fastening and a frictional attachment.

Fig. 4c) finally shows another interesting variant for the attachment of the proposed measuring electrode 1, in which the support structure 5 on the one hand and the body component 22 on the other hand engaged with each other Velcro layers 27, 28, so that between these two components 1, 22 a Connection in the manner of a Velcro closure results. The carrier structure-side Velcro layer 28 can in principle be provided by the carrier structure 5 itself, in particular if the carrier structure 5 is a textile carrier structure 5.

In particular, in order to be able to perform an above-mentioned operator event monitoring, it is preferably the case that the measuring electrode 1 extends in the mounted state along an above-mentioned body component 22 of the motor vehicle. Here and preferably, at least one elongated electrode surface 8 defined by the applied yarn 6 extends along the body component 22, more preferably along the bumper of the motor vehicle. In this case, the measuring electrode 1, in particular the proximity sensor 2 as a whole, is arranged in a cavity of the respective body component 22.

According to another teaching, which has independent significance, the capacitive proximity sensor 2 of the motor vehicle is claimed as such. In addition to an above-mentioned measuring controller 11, the proximity sensor has at least one measuring electrode 1 according to the proposal. In that regard, may be made on the other hand, all statements to the measuring controller 11 on the one hand and the measuring electrode 1 on the other hand. According to another teaching, which also has independent significance, the body component 22 of the motor vehicle, to which a proposed proximity sensor 2 is attached, is claimed as such. In that regard, reference may be made to all embodiments of the proposed Proximity Sensor 2.

According to another teaching, which also has independent significance, a method for producing a proposed measuring electrode 1 is claimed.

Essential according to the further teaching relating to the production method for the measuring electrode 1 is that the conductive yarn 6 is applied to the carrier structure S in a plurality of stitches 7. Sewing the conductor structure 4 on the support structure 5 is accompanied by the above-mentioned advantages in terms of increased flexibility and reduced costs.

The application of the electrically conductive yarn 6 takes place in a preferred embodiment by means of at least one needle and further preferably by means of a sewing unit, which regularly allows a fully automated sewing process. In that regard, the above-mentioned possibility of mass production of the proposed measuring electrode 1 results.

After the application of the conductive yarn 6, ie after the production of the electrode surface 8 and possibly the generation of at least a part of the measuring control 11, it is preferably provided that the support structure 5 is cut or bound by a cutting process and / or punching process. This type of packaging can be carried out in a particularly simple and, above all, automatable way. During assembly, the above-mentioned Befestigungsöffhungen 24 can be introduced into the support structure 5.

In principle, a certain preforming of the carrier structure 5 or of the measuring electrode 1 can be provided as a whole. For example, it is conceivable that before or after the assembly, the carrier structure 5 is rolled together with the conductive structure 4, so that a total of one measuring electrode 1 results in the manner of a circular conductor.

Claims

claims

1. Measuring electrode for a capacitive proximity sensor (2) of a motor vehicle having a conductor structure (4) and a flat carrier structure (5) for receiving the conductor structure (4), wherein the conductor structure (4) has at least one electrically conductive yarn (6) which is applied in a plurality of stitches (7) on the support structure (5).

2. Measuring electrode according to claim 1, characterized in that the applied yarn (6) on the carrier structure (5) defines an electrode surface (8) of the measuring electrode (1), preferably that the applied yarn (6) on the carrier structure ( 5) defines an electrode surface (S) in that the applied yarn (6) at least partially fills out and / or outlines the electrode surface (8).

3. Measuring electrode according to claim 1 or 2, characterized in that the electrically conductive yarn (6) along at least one seam line (9) in at least one stitch on the carrier structure (5) is applied.

4. Measuring electrode according to one of the preceding claims, characterized in that the conductive yarn (6) consists of a stainless steel material or of a copper material

5. measuring electrode according to any one of the preceding claims, characterized in that the support structure (5) is configured as such limp, preferably, that the measuring electrode (1) is configured as such limp.

6. Measuring electrode according to one of the preceding claims, characterized in that the carrier structure (5) is a textile structure, or that the carrier structure (5) is a film structure.

7. measuring electrode according to one of the preceding claims, characterized in that the electrode surface (8) is at least partially elongated, preferably that at least two elongated electrode partial surfaces (8a, 8b) are provided, more preferably that the electrode Partial surfaces (8a, 8b) parallel to each other, preferably adjacent to each other, are arranged on the support structure (5).

8. Measuring electrode according to one of the preceding claims, characterized in that the proximity sensor (2) has a measuring controller (11) and that at least part of the measuring controller (11) is arranged on the carrier structure (5), preferably that the measuring controller (11 ) has at least one electrical connection (12) and that the conductor structure (4) provides at least a part of the at least one electrical connection (12)

9. Measuring electrode according to one of the preceding claims, characterized in that the proximity sensor (2), in particular the measuring electrode (1), at least one electrical connection (14, 15) and that the conductor structure (4) at least part of the electrical connection ( 14, 15), preferably, that the electrical connection (14, 15) at least one electrical connection line (16, 17) and / or at least one electrical contact (18, 19).

10. Measuring electrode according to one of the preceding claims, characterized in that the measuring electrode (1) in the assembled state via the support structure (5) on a body component (22) of the motor vehicle is fixed, preferably, that the attachment is a material attachment and / or a positive fastening and / or a frictional attachment is.

11. measuring electrode according to any one of the preceding claims, characterized in that the measuring electrode (I) in the assembled state along a body component (22) of the motor vehicle extends, preferably that at least one by the applied yarn (6) defined, elongated electrode surface ( 8) extends along the body component (22)

12. Capacitive proximity sensor of a motor vehicle with a measuring controller (11) and at least one measuring electrode (1) according to one of the preceding claims.

13. Bodywork component of a motor vehicle, to which a proximity sensor (2) according to claim 12 is attached.

14. A method for producing a measuring electrode according to claim 1, wherein the electrically conductive yarn is applied to the carrier structure in a plurality of stitches.

15. The method according to claim 14, characterized in that the carrier structure (5) after the application of the conductive yarn (6) by a cutting process and / or a punching process cut to length and / or is located.