Detection device, sensor device and method for producing a detection device

Abstract

The invention relates to a detection device, a sensor device and a method for manufacturing the detection device. The invention relates to a detection device for an inductive position sensor, comprising: at least one detection strip (261, 262) having a plurality of detection elements (281, 282) spaced apart from one another, the detection elements being detectable by means of the inductive position sensor (50); the invention relates to a sensor device (1) for detecting at least one sensor tape, comprising at least one sensor tape (2), and a carrier device (21) on which the at least one sensor tape is fixedly arranged, the carrier device (21) having a carrier element (22) and a carrier membrane (24), the sensor elements of the sensor tape being arranged on the carrier membrane (24), and the carrier membrane (24) being fastened to the carrier element (22) in such a way that the sensor elements of the sensor tape are arranged on the carrier membrane (24). The detection element is arranged between the carrier membrane (24) and the carrier element (22) in a sandwich-like manner.

Description

Technical Field

[0001] The present invention relates to a detection device for an inductive position sensor, the detection device comprising: at least one detection band, the detection band having a plurality of detection elements spaced apart from one another, wherein the detection elements can be detected by the inductive position sensor; and a carrier device, the at least one detection band being fixedly arranged on the carrier device. Background Art

[0002] Such detection devices are generally known from the prior art, in particular in combination with inductive position sensors. For example, such inductive position sensors are known in combination with detection devices for determining the position of an adjustable vehicle seat, wherein the inductive position sensor is arranged, for example, on the vehicle seat and the detection device is fastened to a seat rail that is fastened to the original structure of the vehicle. The inductive position sensor detects the detection element of the detection device in such a way that the position of the adjustable vehicle seat can be determined.

[0003] An embodiment variant of an inductive position sensor implemented as a position sensor or as a linear travel sensor is described, for example, in WO 2022 / 156931 A1, wherein the linear travel sensor cooperates with a detection strip. The detection strip is fixed to a first substrate and the linear travel sensor is fixed to a second substrate that is movable relative to the first substrate. The detection strip has a plurality of detection elements that are detected by the linear travel sensor, wherein, based on this, the position of the first substrate receiving the detection strip relative to the second substrate receiving the linear travel sensor is determined by means of an evaluation unit or an evaluation circuit. The detection strip is usually made of metal material and is implemented as a stamped part.

[0004] A problem with such detection devices, which are arranged, for example, in the interior of a vehicle, is that the detection strip is exposed to different ambient media, in particular moisture, dust, dirt, lubricants and / or other materials, so that there is a risk of contamination and corrosion of the detection strip and thus of undesirable influences during detection and, therefore, position determination of the detection strip. Summary of the invention

[0005] It is therefore an object of the present invention to provide a detection device for an inductive position sensor, by means of which undesired influences on the detection of the detection strip and thus on the position determination by the inductive position sensor can be prevented in a simple and reliable manner.

[0006] The object of the invention is achieved by the features of claim 1 .

[0007] According to the invention, the carrier device comprises a carrier element and a carrier membrane, wherein the detector elements of the detector strip are arranged on the carrier membrane and the carrier membrane is fixed to the carrier element in such a way that the detector elements are arranged in a sandwich-like manner between the carrier membrane and the carrier element.

[0008] The detection strip is made of a metallic material, such as copper, aluminum or high-quality steel. The detection strip has a plurality of detection elements, also called vernier pads, which are spaced apart from one another and arranged in a row, wherein a non-coupling section is respectively present between two adjacent detection elements. The detection strip interacts with an inductive position sensor and serves as an inductive coupling region for a stator of the inductive position sensor, wherein the stator has an excitation coil and a sensor coil assembly.

[0009] Preferably, two detection bands are provided, which are preferably arranged in two rows arranged parallel to one another, wherein the distances between the detection elements of the first detection band and the distances between the detection elements of the second detection band are different from one another. In conjunction with an inductive position sensor, the detection bands serve as inductive coupling regions for a stator of the inductive position sensor, wherein a stator is provided for each detection band. By detecting the detection bands with the aid of the inductive position sensor, the position of a substrate receiving the detection band relative to a substrate receiving the inductive position sensor can be reliably and uniquely determined using the known vernier principle.

[0010] The carrier element is in particular a base body made of plastic, which can preferably be produced by an injection molding process. As a result, the carrier element can be produced in a simple and cost-effective manner and in almost any shape. The carrier element has such rigidity and strength that it serves for the dimensional stability of the carrier arrangement and for fixing it to the vehicle component.

[0011] The carrier membrane is likewise made of plastic and serves to accommodate the sensor element. The carrier membrane is flexible and thin and preferably has a wall thickness of a maximum of 120 μm.

[0012] In the finally assembled state of the carrier device, the carrier membrane is fastened to the carrier element in such a way that the detection element is arranged in a sandwich-like manner between the carrier element and the carrier membrane. The carrier membrane is thereby fastened to the carrier element with the side having the detection element in such a way that in the finally assembled state of the detection device and the inductive position sensor, the carrier membrane is arranged between the inductive position sensor and the detection element.

[0013] On the one hand, the carrier membrane is fastened to the carrier element in such a way that the penetration of dust and moisture into the region of the detection element can be reliably prevented. On the other hand, due to the relatively low wall thickness and the low or no electrical conductivity of the carrier membrane, the influence on the detection of the detection strip by the inductive position sensor is negligibly small.

[0014] By means of such a detection device, contact of the detection tape with moisture and dirt can be reliably prevented, whereby undesired influences on the detection of the detection tape and thereby on the position determination can be reliably avoided.

[0015] Preferably, the carrier membrane is bonded to the carrier element. The carrier membrane is bonded to the carrier element at least on the surface surrounding the detection element. In this way, the carrier membrane can be fixed to the carrier element simply and cost-effectively and contact of the detection element with dirt and moisture can be reliably avoided.

[0016] Alternatively, the carrier element is attached to the carrier membrane by injection molding. Here, the carrier membrane together with the detection element of the detection tape fixed thereon is placed in the mold of an injection molding machine and the carrier element is manufactured by an injection molding process. The carrier element is attached to the surface of the carrier element with the detection element by injection molding. By injection molding or back injection molding of the carrier membrane by the carrier element, a fixed connection between the carrier membrane and the carrier element is achieved, especially in areas where no detection element is arranged. In order to ensure adhesion between the carrier membrane and the carrier element over the entire service life, the materials of the carrier element and the carrier membrane are correspondingly coordinated with each other.

[0017] By injection molding the carrier element onto the carrier membrane, the manufacturing complexity of the detection device can be reduced, since the carrier element is already fixed to the carrier membrane during production. No additional step is required to fix the carrier element and the carrier membrane to each other.

[0018] In a preferred embodiment, the detector elements of the detector strip are stamped onto a carrier film. The detector elements here have a wall thickness in the μm or even nm range. The detector elements can be produced in such a way that the conductive pigment is applied to the carrier film. In this way, the detector elements can be produced simply and cost-effectively.

[0019] Alternatively, the detection elements of the detection strip are evaporated onto the carrier membrane. Here, the metal material is evaporated onto the carrier membrane in a vacuum, wherein this process is also called metallization. By means of the metallization, the detection elements can also be manufactured and fixed to the carrier membrane in a simple and cost-effective manner.

[0020] Preferably, the carrier element has at least one recess in which at least one detection element is arranged, wherein the recess is covered by the carrier membrane. As a result, the seal between the region of the detection element and the external environment can be improved.

[0021] In a preferred embodiment, the carrier element has at least one latching element for fixing the carrier element to the vehicle component. In this way, the carrier element and thereby the entire detection device can be simply and releasably fixed to the vehicle component. Here, the detection device can be inserted into the opening with a first end, for example, and prevented from being pushed out of the opening by the latching element. Alternatively, the carrier element can have a plurality of latching elements, which latch with the vehicle component in the assembled state in such a way that the movement of the detection device in all spatial directions is prevented. In this way, the detection device can be simply and cost-effectively fixed to the vehicle component, in particular without additional tools.

[0022] Preferably, the carrier membrane and the detection element form a circuit board, preferably a flexible circuit board, comprising a carrier and a conductive layer, wherein the detection element is formed by the conductive layer. The carrier formed by the carrier membrane is made of an electrically insulating material, in particular plastic, and optionally fiber-reinforced plastic. The conductive layer forms a so-called conductor track (track) and is usually implemented by a thin copper layer. The current circuit board is implemented in such a way that the conductive layer is implemented or the conductor track is implemented in such a way that the detection element is formed by the conductor track. In addition, other components, in particular electronic components, can be arranged on the circuit board, and the components are fixed to the circuit board and electrically connected to the conductive layer, for example, respectively by soldering or conductive adhesive connection.

[0023] The object is also achieved by a sensor device comprising a detection device according to one of claims 1 to 11 and an inductive position sensor which is designed to detect a detection element of the detection device. The sensor device is used in particular for determining the position of an adjustable vehicle seat, wherein the detection device is preferably connected to a guide rail connected to the original structure of the motor vehicle and the inductive position sensor is fastened to the vehicle seat. For advantages, refer to the preceding paragraphs.

[0024] Furthermore, the object is achieved by a method for producing a detection device according to one of claims 1 to 11. Reference is made to the preceding paragraphs for the individual production steps and advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The invention will now be further explained with reference to the accompanying drawings.

[0026] Figure 1 schematically shows a cross section through a detection device according to the invention and an inductive position sensor associated therewith; and

[0027] Figure 2 Schematically shown Figure 1 A perspective view of a detection band of a detection device. DETAILED DESCRIPTION

[0028] Figure 1 The vehicle system arrangement 10 is shown with a first base body 12 and a second base body 14. For example, the first base body 12 is a fixed vehicle seat guide which is fixed to the original structure of the motor vehicle, and the second base body 14 is a vehicle seat rail which is connected to the vehicle seat and can be displaced together with the vehicle seat. The vehicle seat rail engages in the vehicle seat guide in such a way that the vehicle seat rail and thereby the vehicle seat are guided by the vehicle seat guide during an adjustment process, wherein the adjustment is carried out in particular by means of an electric drive unit.

[0029] To detect the position of second base body 14 relative to first base body 12 , detection device 20 is provided on first base body 12 and inductive position sensor 50 is provided on second base body 14 , detection device 20 interacting with inductive position sensor 50 or being detected by inductive position sensor 50 .

[0030] The detection device 20 has a carrier element 22 , a carrier membrane 24 and two detection strips 261 , 262 .

[0031] As in Figure 2 As shown in FIG. 1 , the detection strips 261, 262 extend parallel to each other and have a plurality of detection elements 281, 282. The detection elements 281, 282 of the two detection strips 261, 262 are arranged offset from each other, that is, the distance between the detection elements 281 of the detection strip 261 deviates from the distance between the detection elements 282 of the detection strip 262. When the vernier principle is used, the position of the second base body 14 relative to the first base body 12, that is, the position of the vehicle seat, can be reliably and uniquely determined by the inductive position sensor 50.

[0032] The carrier element 22 is made of plastic, in particular hard plastic, and serves as a supporting element of the detection device 20. The carrier element 22 has a plurality of latching elements 40, by means of which the carrier element 22 is latched to the first base body 12 and thus fixed thereto.

[0033] The carrier membrane 24 is implemented as a flexible plastic membrane and has a wall thickness of 100 μm or less. The carrier membrane 24 is used to receive the detection elements 281, 282 of the detection strips 261, 262 and is fixed to the carrier element 22 in such a way that the detection elements 281, 282 arranged on the carrier membrane 24 are arranged in a sandwich-like manner between the carrier element 22 and the carrier membrane 24. The detection elements 281, 282 are thus separated from the external environment in a dust-proof and moisture-proof manner. The carrier membrane 24 and the detection elements 281, 282 together form a flexible circuit board, on which or next to which electronic components can be arranged in addition to the detection elements 281, 282.

[0034] In order to receive the carrier membrane 24, the carrier element 22 has a groove 30 extending in the longitudinal direction, which is laterally delimited by two webs 301, 302 extending in the longitudinal direction. In addition, the carrier element 22 has a recess 321, 322 for each detection element 281, 282 on the bottom section 303 of the groove 30, wherein the detection elements 281, 282 are respectively arranged in a recess 321, 322 and covered by the carrier membrane 24.

[0035] By placing the diaphragm in the groove 30, no protrusion caused by the carrier diaphragm 24 is provided on the side of the detection device 20 facing the position sensor, thereby avoiding the accumulation of moisture and dirt on the interface between the carrier diaphragm 24 and the carrier element 22 and thus preventing the unwanted entry of moisture and dirt into the gap between the carrier element 22 and the carrier diaphragm 24.

[0036] When manufacturing the detection device 20, the detection elements 281, 282 of the detection strip 261 are first fixed to the carrier film 24 or applied to the carrier film 24. The detection elements 281, 282 can be embossed or evaporated onto the carrier film 24. In the embossing of the carrier film 24, a conductive pigment is applied to the carrier film. In the evaporation of the detection elements 281, 282 onto the carrier film 24, a metal material is evaporated onto the carrier film 24 in a vacuum. This process is also called metallization.

[0037] In the next step, the carrier element 22 is manufactured and fixed to the carrier membrane 24 at the same time. The carrier element 22 is manufactured by an injection molding process and is attached to the carrier membrane 24 by injection molding. Here, the carrier membrane 24 together with the detection elements 281, 282 arranged thereon is placed in the mold of the injection molding machine and the carrier element 22 is injection molded by the injection molding process. Here, the carrier element 22 is attached to the surface of the carrier element 22 with the detection elements 281, 282 by injection molding, thereby achieving a fixed connection between the carrier membrane 24 and the carrier element 22. Alternatively, the carrier membrane 24 may be bonded to the carrier element 22.

[0038] By means of such a detection device 20 , contact of the detection strips 261 , 262 with moisture and dirt can be reliably prevented, whereby undesired influences on the detection and thus the position determination of the detection strips 261 , 262 can be reliably avoided.

[0039] Reference numerals list

[0040] 10Vehicle system layout structure

[0041] 12 First Matrix

[0042] 14 Second Matrix

[0043] 20 Detection device

[0044] 21 Carrier device

[0045] 22 Carrier element

[0046] 24 Carrier Diaphragm

[0047] 261 detection belt

[0048] 262 detection belt

[0049] 281 detection element

[0050] 282 detection element

[0051] 30 slots

[0052] 301 splice

[0053] 302 splice

[0054] 303 bottom section

[0055] 321 gap

[0056] 322 gap

[0057] 40 locking elements

[0058] 50 inductive position sensor

Claims

1. A detection device for a position sensor (50) for induction, the detection device comprising: at least one detection strip (261, 262) having a plurality of detection elements (281, 282) spaced apart from one another, wherein the detection elements (281, 282) are detectable by an inductive position sensor (50); and a carrier device (21), on which the at least one detection band (261, 262) is fixedly arranged, It is characterized in that The carrier device (21) comprises a carrier element (22) and a carrier membrane (24), wherein the detection elements (281, 282) of the detection strips (261, 262) are arranged on the carrier membrane (24), and the carrier membrane (24) is fixed to the carrier element (22) so that the detection elements (281, 282) are arranged in a sandwich-like manner between the carrier membrane (24) and the carrier element (22).

2. The detection device according to claim 1, characterized in that The carrier film (24) is adhesively bonded to the carrier element (22).

3. The detection device according to claim 1, characterized in that The carrier element (22) is produced by an injection molding process, wherein the carrier element (22) is injection molded onto the carrier membrane (24).

4. The detection device according to any one of the preceding claims, characterized in that The detection elements (281, 282) of the detection strips (261, 262) are printed onto the carrier film (24).

5. The detection device according to any one of claims 1 to 3, characterized in that The detector elements (281, 282) of the detector strips (261, 262) are vapor-deposited onto the carrier film (24).

6. The detection device according to any one of the preceding claims, characterized in that The carrier element (22) has at least one recess (321, 322) in which at least one detection element (281, 282) is arranged, wherein the recess (321, 322) is covered by the carrier membrane (24).

7. The detection device according to any one of the preceding claims, characterized in that The detection strips (261, 262) are arranged between the carrier membrane (24) and the carrier element (22) in a moisture-proof and dust-proof manner relative to the environment.

8. The detection device according to any one of the preceding claims, characterized in that A first detection band (261) and a second detection band (262) are provided, each having a plurality of detection elements (281, 282) and arranged parallel to each other.

9. The detection device according to any one of the preceding claims, characterized in that The carrier element (22) has at least one latching element (40) for fastening the carrier element (22) to a vehicle component.

10. The detection device according to any one of the preceding claims, characterized in that The carrier membrane (24) and the detection elements (281, 282) form a circuit board comprising a carrier and a conductive layer, wherein the detection elements (281, 282) are formed by the conductive layer.

11. The detection device according to claim 10, characterized in that The circuit board is a flexible circuit board.

12. Sensor equipment, including: The detection device (20) according to any one of claims 1 to 11, and An inductive position sensor (50) is implemented for detecting a detection element (281, 282) of the detection device (20). 13 . Method for producing a detection device ( 20 ) according to claim 1 .

Images