Sensor plate with integrally formed studs

Abstract

The invention relates to a sensor plate (1) for measuring force distributions, comprising a sensor element (2) having at least one sensor cell (3) and at least one pressure-directing element (4), which is connected to and positioned on the sensor element (2) in order to transmit force to the at least one sensor cell (3), the pressure-directing element (4) being a flat plane having at least one elevation in the form of a pressure-directing stud (5), each sensor cell (3) being assigned a pressure-directing stud (5) positioned thereon, and the size and shape of the pressure-directing element (4) being such that it covers the sensor element (2) at least for the most part.

Description

[0001] 202403263 1

[0002] Description

[0003] Sensor plate with molded studs

[0004] The present invention relates to the measurement of force distributions using printed electronics as well as the measurement of force distributions with force guide studs which are fixed on a separate element, not in a fixed position on the sensor.

[0005] It is known that only force distributions can be measured, not total forces, because in addition to the discrete sensor positions, force bypasses occur.

[0006] Force bypasses, in this context, refer specifically to unwanted force transmissions that occur outside the intended measurement paths of a sensor. These result in forces not being transmitted exclusively through the sensor cells, but also via other paths – e.g., through adjacent structures, materials, or connecting elements. This can distort the measurement results.

[0007] Even a slight misalignment between the force-guiding stud and the sensor during operation changes the sensor's characteristics or calibration curve (measured value vs. applied force). This results in significant inaccuracies in the measured force.

[0008] The sensor and the conductor tracks must be protected against abrasion / damage.

[0009] The force-conducting element and sensor must be reliably protected against detachment and infiltration by dirt particles.

[0010] GB 2482192B

[0011] US 2020319044 A1 202403263 2

[0012] DE 10 2011 016 344 A1

[0013] One object of the present invention is the development of a compact sensor plate with discrete sensor positions and a force introduction into them, resulting in a stable and robust sensor characteristic.

[0014] Additionally or alternatively, force transmission without force shunt to enable the measurement of absolute forces and to minimize potential errors in the measured force distribution.

[0015] In any case, the aim is to implement it in the most reliable, economical and robust way possible.

[0016] The problem is solved according to the invention as follows:

[0017] A sensor plate consisting of:

[0018] A sensor element (preferably using pressure-sensitive resistive sensor elements, alternatively electroactive polymers or other capacitive or inductive sensors) with one or more discrete sensitive areas (sensor cells).

[0019] A temperature-sensitive element (e.g., NTC, PTC) is preferably integrated onto the sensor element. Particularly preferably, the temperature sensor is in the form of a long printed electrical conductor, preferably arranged in a meandering shape in the middle.

[0020] Force transmission to the sensor cells via one or more pressure-conducting elements, which are materially bonded to and positioned with the sensor element. 202403263 3

[0021] Pressure guide element with one or more pressure guide studs, each assigned to a sensor cell and positioned accordingly on it, so that a surface-acting load is directed specifically and mainly through one or more sensor cells.

[0022] Sensor element preferably manufactured as printed electronics, at least partially enclosed on one or both sides with at least one first carrier film, preferably a PET film.

[0023] Pressure-conducting element preferably made of a thermoset (e.g. PU / TPU) which is formed in direct contact with the sensor by a shaping process (e.g. casting process) and reacts chemically here, so that on the one hand the shape is retained and on the other hand a firm chemical bond to the sensor is established.

[0024] Alternatively, the pressure guide element is manufactured from a thermoplastic (e.g., TPE / TPU), which, in molten form, is shaped by a molding process (e.g., injection molding) in direct contact with the sensor and solidifies there, so that on the one hand the shape is retained and on the other hand a firm chemical bond to the sensor is established.

[0025] Pressure-guided cleat shape preferably with a linear contact surface on the side facing away from and / or towards the sensor. Preferably a linear or elongated contact surface on the side facing away from the sensor and a larger, wider contact surface in the direction of the sensor cell. For example, this can be achieved by a trapezoidal shape.

[0026] Pressure-guiding element defined as a thin, planar plane with individual elevations in the form of pressure-guiding ridges, in size and shape such that it covers the sensor element at least largely, preferably completely, and thereby protects it. 202403263 4

[0027] The pressure-guiding element is pronounced so that it at least partially, preferably mostly or completely, covers and protects the sensor element laterally.

[0028] The pressure-guiding element is pronounced so that it covers the sensor element at least partially, preferably mostly or completely, also on the back side - on the side of the sensor facing away from the force-guiding elements.

[0029] Preferably, the sensor element is positioned and connected to a carrier plate with its side facing away from the pressure guide tunnel, preferably by bonding and / or welding. The carrier plate preferably consists of a thermoplastic (e.g., polyamide or TPU) with an additional reinforcing layer (e.g., glass fibers). Preferably, an organosheet made of polyamide with glass fiber fabric reinforcement is used.

[0030] In this case, the pressure-guiding element extends beyond the front face of the sensor or the interface between the sensor element and the carrier plate, providing additional protection against detachment and the ingress of dirt.

[0031] In construction with carrier plate:

[0032] The pressure-distributing element extends laterally beyond the carrier plate, thus covering at least most of the carrier plate's front edge. This protects the cut edge against damage and detachment and prevents dirt from penetrating the edge area. Optionally, the pressure-distributing element also extends to the side of the carrier plate facing away from the sensor, offering even more comprehensive protection.

[0033] In other words, the task posed at the beginning is solved by a sensor plate for measuring force distributions, comprising:

[0034] - a sensor element with at least one sensor cell forming a discrete sensitive area, and 202403263 5

[0035] - at least one pressure-guiding element which is connected to and positioned with the sensor element for force transmission to the at least one sensor cell, wherein the pressure-guiding element is designed as a planar plane with at least one elevation in the form of a pressure-guiding ridge, wherein each sensor cell is assigned a pressure-guiding ridge positioned on it, so that a planar acting load is directed specifically and mainly through one or more sensor cells, wherein the pressure-guiding element is designed in size and shape such that it covers at least most of the sensor element and thereby protects it.

[0036] According to a preferred embodiment of the invention, the pressure guide element is made of a thermoset which is formed directly onto the sensor element by a shaping process and reacts to produce a solid chemical compound.

[0037] According to a further preferred embodiment of the invention, the pressure guide element is made of a thermoplastic which, in molten form, is directly formed on the sensor element by a shaping process and reacts to produce a solid chemical compound.

[0038] According to a further preferred embodiment of the invention, the at least one pressure guide tunnel has a linear contact surface on one side facing away from and / or towards the associated sensor cell.

[0039] According to a further preferred embodiment of the invention, the at least one pressure guide rib has a linear or elongated contact surface on one side facing away from the associated sensor cell and a larger, wider contact surface on one side facing the associated sensor cell. 202403263 6

[0040] According to a further preferred embodiment of the invention, the sensor plate comprises a carrier plate which is materially connected to a side of the sensor element facing away from the at least one pressure guide rib, wherein the pressure guide element extends beyond an end face of the sensor element.

[0041] According to a further preferred embodiment of the invention, the pressure-guiding element extends laterally beyond the carrier plate and thus covers at least a large part of an end face of the carrier plate.

[0042] According to a further preferred embodiment of the invention, the sensor plate comprises an integrated temperature-sensitive element, in particular in the form of a centrally arranged, meandering electrical conductor.

[0043] For contacting purposes, the sensor element preferably has a plug outlet, which enables contact with a sensor signal processing unit.

[0044] Preferably, a plug is crimped onto the end of the plug outlet.

[0045] Preferably, the pressure-guiding element also forms a "cable guard" by at least largely enclosing the connector exit and preferably also enclosing the carrier plate in the area of ​​the connector exit, at least on its end face or around its circumference. This prevents damage to the cable exit and the ingress of dirt in the area of ​​the cable exit. Optionally, the cable guard also encloses the connector itself.

[0046] In other words, according to a further preferred embodiment of the invention, the pressure element at least largely encloses a connector outlet of the sensor element to form cable protection. In particular, the pressure-guiding element encompasses the carrier plate in the area of ​​the connector outlet at least at its end face or around its circumference. 202403263 7

[0047] Preferably, the pressure-conducting element forms a "sealing element" near the contact at the cable exit, which has a higher layer thickness at least partially and can therefore serve as a seal against an electronic unit and as splash protection.

[0048] A reaction force measuring system with such a sensor plate.

[0049] A diagnostic system with such a reaction force measurement system and sensor signal transmission and reception unit, as well as a data processing unit and display on an end device.

[0050] In other words, the above-mentioned problem is also solved by a reaction force measuring system comprising a sensor plate according to one of the preceding claims.

[0051] In other words, the above-mentioned task is also solved by a diagnostic system comprising the previously described reaction force measurement system as well as a sensor signal transmission and reception unit, a data processing unit and a display on an end device.

[0052] This results in the following advantages:

[0053] - No assembly steps required to fix the pressure guide element.

[0054] - Particularly good lateral protection of the sensor element against detachment and ingress of foreign substances within its layer structure and against detachment from an optional carrier plate by lateral sealing of the interface.

[0055] - The PU potting process can be carried out without pressure and is possible without damaging the sensor element.

[0056] - Duromer offers very high strength and constant properties over its service life.

[0057] - No separate cable protection required 202403263 8

[0058] Exemplary embodiments and further advantages of the invention are explained below in connection with the following schematic figures. These show:

[0059] Figure 1 shows an exploded view of a sensor plate according to the invention in one embodiment;

[0060] Figure 2 shows a partially transparent view of a sensor plate according to the invention in a further embodiment;

[0061] Figure 3 shows a side view of a sensor plate according to a further embodiment of the invention; and

[0062] Figure 1 shows an exploded view of a sensor plate 1 for measuring force distributions. The sensor plate 1 has a sensor element 2 with at least one sensor cell 3 forming a discrete sensitive area. The sensor plate 1 has at least one pressure-guiding element 4. In the assembled state, the pressure-guiding element 4 is connected to the sensor element 2 and positioned such that it enables force transmission to the at least one sensor cell 3. The pressure-guiding element 4 is designed as a flat surface with at least one raised section in the form of a pressure-guiding groove 5. Each sensor cell 3 of the sensor element 2 is associated with a pressure-guiding groove 5 positioned on it. In this way, a load acting over a surface can be directed in a controlled manner and primarily through one or more sensor cells 3. The pressure-guiding element 4 is sized and shaped such that it covers at least most of the sensor element 2 and thereby protects it.

[0063] The sensor plate 1 has a carrier plate 7. Preferably, the sensor element 2, in its assembled state, is bonded to the carrier plate 7 with its side facing away from the at least one pressure guide ridge 5. Preferably, the sensor element 2 is manufactured as electronics printed onto a carrier film 2a. Preferably, the pressure guide element 202403263 9

[0064] 4 extends beyond one end face of the sensor element 2, thus providing additional protection for it.

[0065] Figure 2 shows a view of a sensor plate 1 according to a further embodiment of the invention, in which the pressure-guiding element 4 is shown transparently for better clarity. In contrast to the illustration in Figure 1, the sensor plate 1 is shown here in its assembled state. The pressure-guiding element 4 extends beyond an end face of the sensor element 2. The pressure-guiding element 4 also extends laterally beyond the carrier plate 7 and thus also covers an end face of the carrier plate 7. This protects the sensor element 2 and the carrier plate 7 from the ingress of dirt in the edge region of the sensor plate 1. Furthermore, the end face of the carrier plate 7 is protected against damage and detachment. Optionally, the pressure-guiding element 4 also extends to the side of the carrier plate 7 facing away from the sensor element 2, providing even more comprehensive protection.

[0066] Figure 3 shows a side view of a sensor plate 1 according to the invention. The sensor element 2, located between the carrier plate 7 and the pressure guide element 4, has a connector outlet 8 for signal transmission. The pressure guide element 4 encloses the connector outlet 8 at least for the most part, thus forming cable protection 9. Preferably, the pressure guide element 4 encloses the carrier plate 7 in the area of ​​the connector outlet 8, at least at its end face or around its circumference.

[0067] The pressure-conducting element 4 also forms a sealing element 10 near the contact at the connector outlet 8, i.e., an area where the pressure-conducting element 4 has a greater layer thickness, at least partially. In this way, the pressure-conducting element 4 can serve as a seal against an electronic unit and as splash protection. 202403263 10

[0068] The pressure guide tunnels 5 shown in Figures 1 to 3 have a basic shape with a linear contact surface facing away from the sensor cell 3 and a wider contact surface facing the sensor cell 3. In other words, the pressure guide tunnels 5 have an approximately trapezoidal cross-section.

Claims

202403263 11 Patent claims 1. Sensor plate (1 ) for measuring force distributions, comprising: - a sensor element (2) with at least one sensor cell (3) forming a discrete sensitive area, - at least one pressure-guiding element (4) which is connected to and positioned with the sensor element (2) for force transmission to the at least one sensor cell (3), wherein the pressure-guiding element (4) is designed as a planar plane with at least one elevation in the form of a pressure-guiding tunnel (5), wherein each sensor cell (3) is assigned a pressure-guiding tunnel (5) positioned on it, so that a planar acting load is directed specifically and mainly through one or more sensor cells (3), wherein the pressure-guiding element (4) is designed in size and shape such that it at least largely covers the sensor element (2).

2. Sensor plate (1) according to claim 1, wherein the pressure-guiding element (4) is made of a thermoset which is formed directly on the sensor element (2) by a shaping process and reacted to produce a solid chemical compound.

3. Sensor plate (1) according to one of the preceding claims, wherein the pressure guide element (4) is made of a thermoplastic which, in molten form, is directly formed on the sensor element (2) by a shaping process and reacts to produce a solid chemical compound.

4. Sensor plate (1) according to one of the preceding claims, wherein the at least one pressure guide ridge (5) has a linear contact surface on one side facing away from and / or towards the associated sensor cell (3). 202403263 12 5. Sensor plate (1) according to one of the preceding claims, wherein the at least one pressure guide ridge (5) has a linear or elongated contact surface on a side facing away from the associated sensor cell (3) and a larger, wider contact surface on a side facing the associated sensor cell (3).

6. Sensor plate (1 ) according to one of the preceding claims with a carrier plate (7) which is materially connected to a side of the sensor element (2) facing away from the at least one pressure guide rib (5), wherein the pressure guide element (4) extends beyond an end face of the sensor element (2).

7. Sensor plate (1) according to claim 6, wherein the pressure guide element (4) extends laterally beyond the carrier plate (7) and thus covers at least a large part of an end face of the carrier plate (7).

8. Sensor plate (1) according to one of the preceding claims, wherein the pressure guide element (4) at least largely surrounds a connector outlet (8) of the sensor element (2) to form cable protection, in particular wherein the pressure guide element (4) surrounds the carrier plate (7) in the area of ​​the connector outlet (8) at least at the end face or around the circumference.

9. Sensor plate (1) according to one of the preceding claims, comprising an integrated temperature-sensitive element (8), in particular in the form of a centrally arranged, meandering electrical conductor.

10. Reaction force measuring system comprising a sensor plate (1) according to any one of claims 1 to 9. 202403263 13 11. Diagnostic system comprising a reaction force measurement system according to claim 10, a sensor signal transmission and reception unit, a data processing unit and a display unit.

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