Heating and occupancy detection mat, method for manufacturing such a mat, and vehicle seat

Abstract

The invention relates to a heating and occupancy detection mat (2) for a vehicle seat, the mat comprising: - a single flexible support (4) having a first impermeable main face (12) and a second main face (14) opposite the first main face, - a capacitive sensor with interdigitated electrodes (6) for detecting the presence of an occupant seated in the seat, and - a heating element (10) for heating a seat occupant, the capacitive sensor with interdigitated electrodes (6) and the heating element (10) being printed on said first main face (12) of the flexible support by electronic printing. Figure to be published with the abbreviation: Figure 1

Description

Title of the invention: Heating and occupancy detection mat, method for manufacturing such a mat, and vehicle seat Technical field of the invention

[0001] The present invention relates to the field of comfort equipment for vehicle seats. In particular, the invention relates to a heating and occupancy detection mat for a vehicle seat, a method for manufacturing such a mat, and a vehicle seat. Prior art

[0002] Some vehicle seats are equipped with an occupancy-sensing mat and a heating mat integrated into their seat cushion. The heating mat and the occupancy-sensing mat are arranged one on top of the other. They both cover the entire surface of the seat cushion. However, these seats are expensive. To reduce their cost, some manufacturers have developed a single mat combining heating and detection functions. However, this type of mat is difficult to manufacture because it involves numerous assembly steps. Its manufacturing cost remains high, and often the heating and detection capabilities are compromised. Presentation of the invention

[0003] A first objective of the present invention is to provide a heating and occupancy detection mat that is easier to manufacture.

[0004] A second object of the present invention is to provide a less expensive heating and occupancy detection mat.

[0005] A third object of the present invention is to provide a heating and detection mat with good performance both in terms of heating speed and in terms of quality of occupancy detection.

[0006] A fourth object of the present invention is to propose a simpler and faster method for manufacturing a carpet. Summary of the invention

[0007] The present invention relates to a heating and occupancy detection mat for a vehicle seat, in particular a motor vehicle, the mat comprising: - a single flexible support having a first main waterproof face and a second main face opposite the first main face, - at least one capacitive sensor with interdigitated electrodes capable of detecting the presence of an occupant seated in the seat, and - at least one heating element intended to heat a seat occupant, at least one capacitive sensor with interdigitated electrodes and at least one heating element being printed on said first main face of the flexible support by electronic printing.

[0008] Advantageously, no assembly operation is required, as the mat comprises a single support. The capacitive sensors with interdigitated electrodes and the heating element are produced in a single operation.

[0009] The features described in the following paragraphs may optionally be implemented. They may be implemented independently of each other or in combination with each other: - The mat includes conductive tracks connected to at least one capacitive sensor with interdigitated electrodes, said conductive tracks being printed on the first main face of the flexible support by electronic printing. - The first main face of the flexible support is covered with a resin or plastic material. The flexible support is made of plastic material, preferably thermoplastic polyurethane. At least one conductive element among a capacitive sensor with interdigitated electrodes and a heating element is covered with a protective layer, for example a layer of varnish. The mat includes at least one electrical connection box and in which said at least one heating element is provided with two electrical contacts, one end of the conductive tracks and at least one electrical contact of at least one heating element being arranged in the same connection box.

[0010] The invention also relates to a vehicle seat, in particular a motor vehicle seat, said seat comprising a seat and a backrest articulated to the seat, said seat comprising a frame, a layer of foam carried by the frame and a heating and detection mat as described above, the heating and detection mat being carried by the layer of foam.

[0011] Finally, the invention relates to a method for manufacturing a heating and occupancy detection mat for a vehicle seat, in particular a motor vehicle, the method comprising an electronic printing step of at least one capacitive sensor with interdigitated electrodes and at least one heating element on the same first main face of a flexible support, the at least one capacitive sensor with interdigitated electrodes and the at least one heating element being printed simultaneously during a single printing step.

[0012] According to a particular embodiment, the conductive tracks connected to at least one capacitive sensor with interdigitated electrodes are printed on the first face main of the flexible support by electronic printing during said single printing step.

[0013] According to one embodiment, the process includes a step of coating at least one conductive element among at least one capacitive sensor with interdigitated electrodes and at least one heating element, with a protective layer, for example a layer of varnish. Brief description of the figures

[0014] [Fig-1] is a diagram representing a cross-sectional view of part of a heating and detection mat according to the present invention;

[0015] [Fig.2] is a diagram representing a top view of the heating and detection mat shown in [Fig.1]; and

[0016] [Fig.3] is a diagram schematically representing a top view of part of a seat according to the present invention.

[0017] Detailed description of the invention In the description that follows, the terms "lower" and "upper" are defined when the detection device according to the invention is arranged as illustrated in [Fig. 1], and are in no way limiting.

[0018] The present invention relates to an example of a heating and detection mat according to the present invention. This mat is intended for a vehicle such as a motor vehicle, truck, train, airplane or boat.

[0019] With reference to Figures 1 and 2, the heating and occupancy detection mat 2 illustrated by way of example of the present invention comprises a single flexible support 4, five capacitive sensors with interdigitated electrodes 6 adapted to detect the presence of an occupant sitting on the seat, conductive tracks 8 connected to the capacitive sensors with interdigitated electrodes 6 and a heating element 10 adapted to heat the occupant of the seat.

[0020] The flexible support 4 has a first main face 12 waterproof and a second main face 14 opposite to the first main face.

[0021] The first main face 12 is non-porous or, in other words, impermeable. According to a first embodiment shown in Figures 1 and 2, the flexible support 4 is entirely made of a plastic material such as, for example, thermoplastic polyurethane known by the acronym TPU, polyethylene terephthalate known by the acronym PET, polycarbonate known by the acronym PC or polyimide known by the acronym PI, polydimethylsiloxane known by the acronym PDMS or silicone. According to a second embodiment not shown, the flexible support 4 is a fabric made of natural fibers, woven or non-woven, and coated with a resin or a material plastic such as one of the plastics mentioned above, namely TPU, PET, PC or PI. Advantageously, the capacitive sensors with interdigitated electrodes 6 are printed on the first main face 12 by electronic printing. Each sensor comprises two coplanar, comb-shaped electrodes that interpenetrate each other. Each electrode is connected to a conductive track 8. One electrode is intended to be connected to a potential between 5 and 12 volts. The other electrode is connected to ground. The electrodes are not shown in detail in the figures. The heating element 10 is also printed on the first main face 12 by electronic printing. The heating element 10 consists of a metal wire or a metal track, preferably a copper wire. It extends across the first main face 12 in a sinusoidal pattern. It has an electrical contact 18, 20 at each of its ends.

[0022] Advantageously, the capacitive sensors with interdigitated electrodes 6 and the heating element 10 are printed simultaneously during the same printing operation. This single printing operation allows for faster and cheaper manufacturing of heating and detection mats. Preferably, the conductive tracks 8 are also printed on the first main face 12 by electronic printing. Advantageously, the conductive tracks 8 are printed simultaneously with the conductive tracks 8 and the heating element in order to further reduce manufacturing costs.

[0023] With reference to [Fig. 1], the heating and sensing mat may also include a protective layer 16 covering the capacitive sensors with interdigitated electrodes in order to protect them. A protective layer 16 may also cover the heating element 10. This protective layer 16 is, for example, made of a varnish or a dielectric substance.

[0024] As shown in [Fig. 2], the mat has a generally rectangular shape. The conductive tracks 10 extend parallel to each other in the longitudinal direction of the mat. The mat 2 further comprises a first electrical connection box 22 and a second electrical connection box 24 fixed to the upper edges of the mat. The ends of the conductive tracks 10 connected to the capacitive sensors located on the left side of the mat and the electrical contact 18 of the heating element are mounted in the same first electrical connection box 22. The ends of the conductive tracks 10 connected to the capacitive sensors located on the right side of the mat and the electrical contact 20 of the heating element are mounted in the same second electrical connection box 22.

[0025] Alternatively, the mat 2 comprises a different number of capacitive sensors at interdigitated electrodes such as for example one, two, three, four or six capacitive sensors with interdigitated electrodes.

[0026] Alternatively, the mat 2 comprises a different number of heating elements such as, for example, two, three or four heating elements.

[0027] The invention also relates to a method for manufacturing the heating and occupancy detection mat described above. The method comprises an electronic printing step of the capacitive sensors with interdigitated electrodes 6 and the heating element 10 on the same first main face 10 of the flexible support 4. During this printing step, the capacitive sensors with interdigitated electrodes and the heating element are printed simultaneously in this single electronic printing step. This electronic printing can be carried out, for example, by screen printing, inkjet printing, roll-to-roll printing, or photolithography. Advantageously, the 8 conductive tracks are also printed simultaneously during this single electronic printing step.

[0028] Preferably, this printing step is followed by a step in which a protective layer 16 is deposited on the capacitive sensors with interdigitated electrodes. This protective layer can also be deposited on the conductive tracks 8. This protective layer can also be deposited on the heating element.

[0029] The invention also relates to a vehicle seat 30. The seat comprises a seat 32 and a backrest 34 hinged to the seat. The seat includes a frame (not shown), a foam layer 36 supported by the frame, and a heating and sensing mat 2 as described above. The heating and sensing mat is supported by the foam layer 36. Preferably, the second main face 14 of the flexible support is in contact with the foam layer.

[0030] When the heating and sensing mat is installed on the seat, the conductive tracks 8 extend close to the side edges of the seat 30.

Claims

Demands

1. A heating and occupancy detection mat (2) for a vehicle seat, in particular a motor vehicle, the mat (2) comprising: - a single flexible support (4) having a first main face (12) impermeable and a second main face (14) opposite the first main face, - at least one capacitive sensor with interdigitated electrodes (6) suitable for detecting the presence of an occupant seated on the seat, and - at least one heating element (10) intended to heat an occupant of the seat, the at least one capacitive sensor with interdigitated electrodes (6) and the at least one heating element (10) being printed on said first main face (12) of the flexible support by electronic printing.

2. Heating and sensing mat (2) according to claim 1, which includes conductive tracks (8) connected to at least one capacitive sensor with interdigitated electrodes (6), said conductive tracks (8) being printed on the first main face (12) of the flexible support by electronic printing.

3. Heating and detection mat (2) according to any one of claims 1 and 2, wherein the first main face (12) of the flexible support is covered with a resin or a plastic material.

4. Heating and detection mat (2) according to any one of claims 1 and 2, wherein the flexible support (4) is made of plastic material, preferably thermoplastic polyurethane.

5. Heating and sensing mat (2) according to any one of claims 1 to 4, wherein at least one conductive element among an interdigitated electrode capacitive sensor (6) and a heating element (10) is covered with a protective layer (16), for example a varnish layer.

6. Detection heating mat (2) according to any one of claims 2 to 5, comprising at least one electrical connection box (22, 24) and in which said at least one heating element (10) is provided with two electrical contacts (18, 20), one end of the conductive tracks (8) and at least one electrical contact (18, 20) of at least one heating element being arranged in the same connection box.

7. Vehicle seat (30) in particular motor vehicle seat, said seat comprising a seat (32) and a backrest (34) articulated to the seat, said seat comprising a frame, a layer of foam (36) supported by the frame and a heating and sensing mat (2) according to any one of claims 1 to 6, the heating and sensing mat being supported by the layer of foam.

8. Method of manufacturing a heating and occupancy detection mat (2) for a vehicle seat, in particular a motor vehicle, the method comprising an electronic printing step of at least one capacitive sensor with interdigitated electrodes (6) and at least one heating element (10) on the same first main face (12) of a flexible support, the at least one capacitive sensor with interdigitated electrodes (6) and the at least one heating element (10) being printed simultaneously in a single printing step.

9. A manufacturing method according to claim 8, wherein conductive tracks (8) connected to at least one capacitive sensor with interdigitated electrodes (6) are printed on the first main face (12) of the flexible substrate by electronic printing during said single printing step.

10. A manufacturing method according to any one of claims 8 and 9, comprising a step of coating at least one conductive element among at least one capacitive sensor with interdigitated electrodes (6) and at least one heating element (10), with a protective layer (16), for example a layer of varnish.

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