WO2019234204A1

WO2019234204A1 - Motor vehicle bodywork part comprising a coating forming an capacitive sensor

Info

Publication number: WO2019234204A1
Application number: PCT/EP2019/064899
Authority: WO
Inventors: Frédéric Viot; Sophie Vidal; Georges FRAPPA; Jérôme Grando; Kevin Cheval
Original assignee: Compagnie Plastic Omnium
Priority date: 2018-06-07
Filing date: 2019-06-06
Publication date: 2019-12-12
Also published as: EP3804139A1

Abstract

The invention relates to a motor vehicle bodywork part (10) consisting of a plastic material, comprising: at least one face (20, 21) provided with a coating (30); a means (40) for measuring a variation of an electrical parameter relating to the coating (30); and means (90) for connecting the coating (30) to the means (40) for measuring a variation of an electrical parameter relating to the coating (30), the coating (30) and the measuring means (40) defining a capacitive sensor (60) that can detect at least one previously defined motif.

Description

MOTOR VEHICLE BODY COMPONENT COMPRISING A COATING FORMING A CAPACITIVE SENSOR

The present invention relates to the field of the automotive industry, and more particularly object detection systems of the electric sensor type, with or without contact, for a body part of a motor vehicle. An electric sensor is a sensor detecting a variation of an electrical parameter.

Body parts are known which are rear doors equipped with motor designed to perform the functions of opening and closing of the opening. Such openings can be equipped with object detection systems, with or without contact, such as anti-pinch devices or activation / opening / closing control devices.

In the case of an anti-pinch device, the object detection system makes it possible to prevent the jamming of an object obstructing between the opening leaf, and at least one adjacent fixed element when the sash is closed. , especially in the case where this object is a part of the body of a user.

In the case of a control device, the object detection system allows the opening of the opening by simple approximation or by simple contact with a portion of the opening.

Various types of object detection system are known, such as mechanical sensors of the switch type, resistive sensors, acoustic sensors, optical sensors, magnetic sensors or capacitive sensors.

These capacitive sensors can detect with or without contact objects of various kinds, metallic or non-metallic. These sensors are based on the detection of a variation of capacity. The capacitance between an active electrode of the sensor and the electric potential of the earth is measured. An object placed between this active electrode and the electric potential of the earth influences the value of this capacitance.

Existing solutions are sensors manufactured independently of the part, and reported to the body part. It follows:

- complex architecture and difficulty of installation because the space allocated in the vehicle is often very small;

a multiplicity of components to be assembled on the part;

- A need for many assembly operations, modifying the conventional chains of assemblies.

In addition, by adding an element to the part, it is often necessary to restrict the detection zone. In addition, such sensors are visible elements that are unattractive.

Finally, it is possible that the sensor detects a variation of capacity while no action is desired, for example during the cleaning of the vehicle using a pressure washer, which would lead to the realization of this action. undesirable (eg opening of an opening). Other reasons for undesirable action may be listed by way of example: a pet, the proximity of a high-voltage line, the influence of electronic equipment of the vehicle, or the meteorological conditions such as the rain or snow ...

The object of the invention is to remedy these drawbacks by providing a part equipped with a sensor using a coating of the part as a detection means while avoiding the realization of undesirable actions.

Thus, the object of the invention relates to a body part of a motor vehicle made of plastic material comprising:

at least one face provided with a coating,

a means for measuring a variation of an electrical parameter related to the coating, and

- Connection means of the coating by measuring a variation of an electrical parameter related to the coating, the coating and the measuring means defining a capacitive sensor capable of detecting at least one previously defined pattern.

With such a part, it is possible to cover a larger area of detection than most sensors through the use of a capacitive sensor.

In addition, the latter is closer to the outside by being constituted by a coating applied on one side of the bodywork part.

The ability of the sensor to detect a specific sequence for performing an action makes it possible to ensure that the action does not take place when it is not desired.

This solution also allows a higher level of integration with existing solutions: integrated solution in the coating at the time of painting finish for example.

According to the invention, the term "bodywork part of a motor vehicle" a part formed of one or more main bodies of plastics material, the part having at least two faces, a face is turned towards the outside of the vehicle (named "Outer face" in the following description) and a side facing the vehicle interior (called "internal face" in the following description), compared to a mounted vehicle. Each of these two faces may be provided with the coating of which the variation of a related electrical parameter will be measured. Generally, the outer face of the piece is visible to an observer located at the outside of the vehicle mounted. Conversely, the outer face of the part is generally not visible to an observer located outside the mounted vehicle.

This solution is discrete because it does not consist of components to be mounted in the visible area by an operator.

Finally, this solution is compact because it only concerns a micro thickness between 10 and 50 micrometers of coating.

The part may further comprise one or more of the following features, taken alone or in combination:

the previously defined pattern is a rhythmic pattern, preferably composed of a series of successive contacts of a predefined duration;

- The previously defined pattern is a pattern composed of several points interconnected during the realization of the pattern or forming isolated key areas;

the coating is able to adhere to the plastics material of the part and has an electrical resistance of less than 20 kΩ at 300 k, preferably less than 5 kΩ, more preferably less than 3 kΩ;

the coating contains electrically conductive fillers, chosen alone or in combination in the following group of charges: graphite, metals, such as copper, silver, iron, indium, graphite alloy and metal, carbon black;

the coating contains more than 10% by weight of conductive filler, preferably between 20% and 60% by weight;

the coating is selected from the following group of coatings: a body part paint; a primary; a base ; a varnish ; a metallic film; an electrically conductive substrate; an electrically conductive coating;

the coating is covered with at least one other coating selected from the group of coatings: an antifouling protection varnish, a base, a paint varnish;

the connection means are overmolded in the part or connected to a portion of coating extended on at least a portion of a non-visible face of the part;

the part constitutes an opening of a motor vehicle, a bumper, a wing, a hood, a roof;

the capacitive sensor forms a body of a vehicle control system, such as an opening system of the opening, a control system of a light device, a control system of a sound device or a control system of an air conditioning control device inside the passenger compartment;

the bodywork part is a tailgate type opening and the face of the part includes a police plate area covered by the coating;

the measuring means is a means of measuring the capacitance between the coating and the electric potential of the earth;

the coating is covered with a plastic wall;

the measuring means is a means for measuring a variation of electrical charges of the coating;

- The face of the workpiece forms a first face of the workpiece at least partially covered by the coating and a face of the workpiece opposite to the first face comprises a plurality of areas covered by coating facing the first face covered by the coating; and

- The face of the part is partially covered by the coating;

The invention will be better understood on reading the appended figures, which are provided by way of examples and are in no way limiting, in which:

FIG. 1 illustrates an example of a motor vehicle body part according to the invention;

FIGS. 2A and 2B illustrate a detail of FIG. 1, in order to clearly illustrate the means of connection between the coating and the measurement means;

FIG. 3 illustrates an example of a motor vehicle body part according to the invention, the coating of which forms an element of a capacitive sensor;

FIGS. 4A to 5B illustrate two exemplary embodiments in which the positioning of the coating and / or the covering of the coating are different;

FIGS. 6A and 6B illustrate an example of a geographical pattern at the level of a tailgate type opening constituting an example of a part according to the invention;

FIG. 7 illustrates an example of a rhythmic pattern according to the invention;

FIG. 8A illustrates the external face of a skin of a tailgate type opening constituting an example of a part according to the invention;

FIG. 8B illustrates the internal face of a skin of a tailgate type opening constituting an example of a piece according to the invention;

- Figure 9 shows an embodiment of the placement of the connection means of the coating to the measuring means;

FIG. 10 illustrates an example of a component constituting a hatch-type opening, mounted on a vehicle, in the closed position;

- Figure 11 shows a section along A of Figure 10, illustrating a vehicle control system whose action is controlled from a tailgate, provided with a capacitive sensor;

FIGS. 12A and 12B illustrate an exemplary embodiment of a tactile sensor, in which coating is covered with a varnish;

- Figure 13 shows a section along A of Figure 10, illustrating a vehicle control system whose action is controlled from a tailgate, provided with a sensor according to the invention; and

- Figure 14 shows an embodiment of a sensor according to the invention comprising the part according to the invention, two faces comprise areas covered by the coating.

In all of these figures, the X, Y and Z axes correspond to the usual orientation axes of motor vehicles:

X: longitudinal axis X (according to the length of the vehicle), the X axis being directed towards the rear of the vehicle;

- Y: transverse axis Y (according to the width of the vehicle);

- Z: vertical axis Z (according to the height of the vehicle).

Referring now to Figure 1, which illustrates an example of a body part 10 of a motor vehicle, plastic, having at least one face 20 provided with a coating 30. The body part 10 comprises means of connection 90 of the coating 30 to a measuring means 40 of a variation of an electrical parameter related to the coating 30. The face 20 may be the outer face of the part 10, that is to say the one visible from the outside the vehicle when the part 10 is mounted on a vehicle.

In all the embodiments and examples described in FIGS. 1 to 5B, 9, 12A, 12B and 14, the bodywork part 10 according to the invention comprises a plastic main body 11, at least a portion of which is partially covered by In all the embodiments and examples described in FIGS. 6A, 8A, 8B, 10, 12 and 13, the bodywork part 10 according to the invention is of the hatchback type and comprises two main bodies made of plastic material, namely a skin 12 and a lining 14. Of course, the bodywork part may be an opening of a different type, a bumper, a wing, a hood, a roof and may include more than two main bodies of material plastic.

FIGS. 2A and 2B illustrate a detail of FIG. 1, in order to clearly illustrate the assembly between the coating 30 and the connecting means 90 of the coating 30 by means of measurement 40.

The coating 30 is a coating adapted to the outer plastic body parts. Thus, its formulation must in particular allow the coating 30 to be able to adhere to the plastics material (for example a treated polypropylene) of the part 10. The coating 30 may cover the whole of the face 20 or only or several parts thereof. In the description, all resistance values are measured using an ITW Ransburg resistivity meter, using electrodes 25mm apart and positioned in the center of a 200mm by 600mm rectangular plate. These measurements are carried out for coatings having a thickness of between 10 and 30 microns, at a temperature of 300K.

A primer conventionally used in a car body part paint line has a resistance greater than 30 kΩ and less than 1 MW, measured according to the previously described protocol. Thus, the resistivity of the primer layer is between 1 2MΩ.m and 40MQ.m.

According to the invention, a coating 30 having a low electrical resistance is used, which makes it possible to carry an electrical signal and to transmit any alteration of the latter. For example, a coating having a strength of less than 20 kΩ can be used. According to the invention, a coating having a resistance of less than 20 kΩ, preferably less than 5 kΩ, more preferably less than 3 kΩ is used. The intrinsic resistivity of the coating 30 becomes less than 1 MΩ.m, preferably 200kΩ.m, more preferably less than 120kΩ.m.

The coating 30 thus provides better conductivity on the surface of the part 10.

According to one embodiment, the coating 30 is a coating enriched with electrical conductive pigments. The amount of the pigments is defined according to the conductivity of the pigment used, therefore depending on the nature of the pigment. The charges, which are conductive pigments, may be chosen alone or in combination in the following group of charges: graphite in its various forms (tube, nanotubes, powders), metals such as copper, silver, iron, indium, in different forms (tube, powder, wire), graphite alloy and metal.

In general, the coating 30 comprises more than 10% by weight of pigments, preferably between 20% and 60% by weight.

The particle size of the pigments is preferably less than 25 micrometers. Such granulometry also makes it possible to obtain better dispersibility and to increase the distribution of the pigments in the coating.

The coating 30 may be chosen from the following coatings:

- a painting for bodywork part;

a primer, that is to say the first coating applied on the surface of the piece in a paint line;

a base, that is to say the coating applied on the primary in a paint line;

a varnish, that is to say the coating applied on the base in a paint line; a metallic film;

an electrically conductive substrate;

- an electrical conductive coating.

Thus, according to one embodiment, the coating 30 is a primer for automobile body parts enriched with electrical conductive pigments.

In a conventional painting process, a base, then a varnish, is applied to a primer to obtain a painted surface. It should be remembered that the painting step of a motor vehicle part made of plastic generally comprises a surface treatment step, followed by steps of applying three different coatings on the part. A first coating, called primary, has the function of promoting the attachment to the part of the second coating, improving the conductivity and adhesion of the base (color layer). Thus, in a conventional painting process, the primer provides a conductive coating for retaining and attracting the following coating layers by electrostatism. A second coating, called base, has the function of giving color to the room. Finally, a third coating, called varnish, has the function of protecting the base layer against external aggression.

According to this embodiment, the coating 30 comprises:

a mono or bi-component polyurethane resin compound, conductive fillers of the carbon black type and an organic solvent of the xylene, butyl acetate or butyl glycol acetate type, the coating may also comprise a solvent based on water, ether glycol and / or pyrrolidone;

- charges of conductive pigments; such charges can be chosen alone or in combination in the following group of charges: graphite in its various forms (tube, nanotubes, powders), metals such as copper, silver, iron, indium, in various forms (tube, powder, wires), graphite and metal alloy, carbon black.

According to one embodiment, the coating 30 may be applied to a conductive primer covering the face 20.

According to one embodiment, the coating 30 may be covered with one or more other coatings 100. These other coatings 100 may be chosen alone or in combination from the following coatings:

an anti-fouling protection varnish, making it possible to avoid erroneous detection due to the presence of disturbing elements of the rain, dirt, etc. type. ;

a base, that is to say the coating applied on the primary in a paint line; a varnish, that is to say the coating applied on the base in a paint line; preferably, the varnish is an antifouling varnish, making it possible to avoid erroneous detection due to the presence of disturbing elements such as rain, dirt, etc. ;

According to one embodiment, the coating 30, or the succession of coatings, can also be covered with a plastic wall, allowing optimum protection of the coating 30.

According to one embodiment, the coating 30 corresponds to the paint for bodywork part. In other words, the coating 30 corresponding, in this embodiment, to all the different layers necessary for a painting process, these different layers generally corresponding to a primer layer, a base layer and one or more layers of varnish.

FIGS. 2A and 2B illustrate a detail of FIG. 1, in order to clearly illustrate the connection means 90 between the coating 30 and the measuring means 40.

According to a first example (FIG. 2A), the connection means 90 "pass through" the thickness of the plastic main body 11 of the part 10. To do this, a recess is provided during the molding of the main body 11 of the piece 10, the recess is made after molding and machining. The connection means 90 are then passed through this recess in order to reach the coating 30. Another solution consists of overmolding a metal insert acting as a connection means 90. This solution allows simple assembly, and ensures a good contact between the coating and the coating 30.

According to another exemplary embodiment (FIG. 2B), the connection means 90 come into contact with the coating 30 at the edge of part 10. To do this, the coating 30 is extended from the face 20 to a portion of the internal face. not visible 21 of the part 10, in order to come into contact with the connection means 90.

The connection means 90 may be of different types, as for example as illustrated in FIG. 9. In this example, it is a bent pin 120 comprising two parts, a part 130 in contact with the coating 30 and a portion 140 passing through the main body 11 to the workpiece 10. The end 140 opening on the other side of the workpiece 10 can then be connected to the measuring means 40.

Pin 120 can be replaced by a threaded rod. This rod then has an end, for example a base, in contact with the conductive coating. The rod passes through the main body of the piece 10. The end of the threaded rod opening on the other side of the piece 10 can then be connected to the measuring means 40.

Alternatively and in the same spirit as these two examples, it is possible use a staple, a shutter or grommet, a nut with a non-return tip to ensure contact with the coating 30 or a rivet through the main body of the room 10. It is also possible to use conductive glue to fix a wire to the coating 30 or use the printing of a conductive trace directly on the part 10, for example by inkjet or laser activation, before covering it with the coating 30 .

Capacitive type vehicle control system

According to one embodiment, illustrated in FIG. 3, the bodywork part 10 comprises connection means 90 of the coating 30 to a measuring means 40 of the variation of the capacitance between the coating 30 and the electric potential of the earth 50 Such a means 40 is known to those skilled in the art.

The coating 30 forms the measuring electrode of a capacitive sensor 60, the electrical potential of the earth 50 forming the other electrode.

Indeed, the face 20 of the bodywork part covered by the coating 30 which defines with the measuring means 40 and the electric potential of the earth 50, a capacitive sensor 60 which allows, by detection of change of capacitance of the sensor, detecting that a person or object 70 is approaching the face 20 of the coin. The measuring means 40 measures the capacitance variations between the earth and the measuring electrode, which is constituted by the coating 30. This capacity is modified for example when a part of the body of a person 70 touches the coating 30, or approaching sufficiently close to the coating 30, the person 70 being itself connected electrically (capacitively) to the ground via the ground.

According to this capacitive type embodiment, when a person or an object 70 approaches the coating 30, or when the coating 30 itself approaches a person or an object 70, this induces a variation capacitance between the two electrodes (the earth and the measuring electrode). This variation is detected by the measuring means 40 which sends an instruction to a control unit 80. More specifically, the sensor 60 is able to detect the realization of a particular pattern (prior programming on an electronic control unit), the realization of said pattern being related to the realization of a function (opening / closing of an opening, opening of the fuel door, implementation of a light or sound device, activation of a vehicle equipment, etc.) . This pattern can be by a contact, for example between the hand of a user and the workpiece 10, or when the hand of the user is in the immediate vicinity of the workpiece 10.

The pattern may be a rhythmic pattern, that is to say a sequence of capacity changes induced for example by contacts. These contacts may be of the same duration or of different durations as the intervals between the different contact. These contacts can be made at the same place or in different places. This is visible in Figure 7 showing four contacts 220, 230, 240 and 250 of about the same duration separated from each other by time intervals of different durations.

The pattern may, alternatively or in addition to a rhythmic pattern 215, a geographical pattern 150, that is to say the realization of a particular movement on or in the immediate vicinity of the piece 10. It may for example s' act of the meeting of several points 160, 170 and 180. It could also be a particular movement, for example by placing two fingers on the piece 10 and varying the spacing between them or even touch zones isolated but arranged relative to each other in a particular manner.

An exemplary geographical pattern 150 is shown in Figures 6A and 6B. This pattern 150 comprises three points 160, 170 and 180 that can be interconnected (arrows 190, 200 and 210) to form the triangular pattern. In order to perform an action, it is therefore sufficient to connect the points 160, 170 and 180. The sensor 60 then detects the realization of the pattern as a result of the capacity variation which allows, after processing of this information by the unit 80, to perform the action associated with this predefined pattern.

Examples of realization

Figures 4A to 5B illustrate two embodiments.

According to the example of FIG. 4A, of which FIG. 4B represents an enlargement according to the highlighted area of the part 10 in FIG. 4A, focusing on the assembly between the coating 30 and the connection means 90, the coating 30 is applied on the inner face 21, non-visible, of the part 10 turned towards the inside of the vehicle. The visible outer face 20 is in turn, in this example, covered successively, and conventionally, by three coatings 100 forming a paint: a primer, a base and a varnish. According to this embodiment, the coating 30 is a conductive metal film applied to the non-visible inner face 21 of the part 10. According to an advantageous example, the part 10 has on its non-visible inner face 21 a coating 110 forming an electromagnetic shield, in order to detect a variation in capacity only on one side of the part, in this case only on the side of the visible external face 20 accessible for an end user (end user not shown in FIGS. 4B). This coating 110 also improves the sensitivity of the measurement, because in fact, the measurement is less subject to disturbances. The coating 110 is connected to the mass of the vehicle, in order to fulfill perfectly its role of electromagnetic shield.

According to the example of FIG. 5A, of which FIG. 5B an enlargement according to the zone highlighting the part 10 in Figure 5A, focusing on the assembly between the coating 30 and the connection means 90, the coating 30 is applied to the visible face 20 of the part 10. The coating 30 is covered with two Other coatings 100. According to this embodiment, the coating 30 is a primer coated with a base and a varnish. The base may be of the polyurethane type. Such a base may comprise, for example, a mono- or bicomponent polyurethane system, coloring pigments (for example TiO 2), flakes (for example of the aluminum type) and talc or calcium carbonate type fillers. The varnish may be of the polyurethane type. Such a varnish may comprise for example a mono or bi component polyurethane system, optionally with an acrylic resin. The latter may be an epoxy resin comprising an organic or aqueous solvent (water = glycol ether or pyrrolidone derivatives).

FIG. 8A illustrates the external face 20 of the skin 12 of the hatch-type opening, which is the face intended to be turned towards the outside of the vehicle, thus constituting a visible face of the tailgate 10, when the latter is mounted on the vehicle and is in the closed position.

FIG. 8B illustrates the internal face 21 of the skin 12 of the hatch-type opening, which is the face intended to be turned towards the inside of the vehicle, thus constituting a non-visible face 21 of the tailgate 10, when the latter is mounted on the vehicle and is in the closed position. Furthermore, the inner face of the skin 12 is generally assembled with the outer face of the liner 14, so as to form the tailgate 10.

The coating 30 is applied to at least one of the two faces 20 and 21 of the skin 12 of the tailgate 10 according to any of the embodiments or example described in the application.

In another example, the coating 30 is applied to one of the faces (not shown) of the liner 14. The application of the coating 30 on one of the faces of the liner 14 can be used in addition to or in replacement with the liner 14. application of the coating 30 on one of the faces 20 and 21 of the skin 12. Such an application makes it possible to control an action of the vehicle, even when the tailgate 10 is in the open position and, consequently, its outer face 20 is more difficult to access. Such an application on the liner 14 may occur in non-visible technical areas of the liner 14, such technical areas being located between the recess of a U-shaped lateral upright of the liner 14 to the bonding tracks of the liner 14. window and skin 12.

According to another particular embodiment of the invention, illustrated in FIG. 10, the capacitive sensor 60 forms a member of a vehicle control system. Such a control system can be a system for opening a vehicle opening 10 automobile, control of a light device, a sound device or an air conditioning control device inside the passenger compartment. In the embodiments and examples described in FIGS. 6A, 8A, 8B, 10, 11 and 13, the action is controlled from the outer face 20 of an opening 10 of the tailgate type. When detecting a pattern 150 and / or 215 previously defined, the vehicle control system controls an action of the vehicle. This action may relate directly to the tailgate 10 itself, as non-limiting examples: the opening and closing of the tailgate 10, the actuation of the light devices located within the tailgate 10 or the adjustment of the variation of the opacity of the rear window. However, the action controlled by the control system, after detection of a pattern 150 and / or 215 previously defined on the outer face of the tailgate 10, may also relate to another part or another part of the vehicle, as a non-limiting examples: the opening and closing of another opening or window, the movement of a moving part, such as a spoiler, the actuation of the air conditioning inside the passenger compartment, the adjustment of the sound volume, the control of a device connected to the vehicle, for example a smartphone connected via the Bluetooth communication standard.

Advantageously, the capacitive sensor forms a member of a system for opening an opening coupled to a control of a light device (headlights, indicators). Such a light device could be able to provide a feedback from the vehicle to the user. In particular, the light device may be an LED system, visible from outside the vehicle, for example implanted on an opening such as a tailgate, preferably on its outer face, but also inside the vehicle in a zone dedicated, or on the body of the vehicle near an opening.

The sensor may advantageously detect a rhythmic pattern comprising, in its first part, a sub-pattern of awakening of the vehicle electronics and / or the opening, and in a second part, a second sub-pattern triggering the opening of the opening.

The detection of the waking sub-pattern can also preferably cause the activation of the light device, which is advantageously adapted to attract the attention of the user and thus to signify to the user that the vehicle is awake and is ready to receive the second triggering pattern of the opening. A wake-up time can be provided from the activation of the light device during which the user can reproduce an activation sub-pattern, and during which the LED system is turned on.

An example of a waking sub-pattern is a held contact for one second. An example of an opening trigger sub-pattern is a series of two brief and close contacts.

Thus, the opening system of the opening opens the opening only if the second sub-pattern is performed by the user and is detected by the vehicle during the waking period, which avoids any unwanted opening, for example under the effect of the external environment, as a branch tapping the bodywork.

Figure 10 illustrates a tailgate type 10, mounted on a vehicle, in the closed position.

The coating 30 is applied in the font plate area 22, which corresponds to a recess (near the illumination) of the outer face 20, such recess being concealable for an outside observer observing the rear of the vehicle. This police plate area 22, which could be uncoated with paint, constitutes a portion of the outer face 20, that is to say an outward facing face of the vehicle, when the tailgate 10 is mounted and closed. on the vehicle.

In another example, the coating 30 is applied to a visible portion of the outer face 20 for an outside observer, in the form of decoration while fulfilling its technical function.

FIG. 11 represents a section along A of FIG. 10, illustrating the vehicle control system whose action is controlled from the tailgate 10.

To describe FIGS. 11 and 13, we assume that the vehicle control system, whose action is controlled from the tailgate 10, is a system making it possible to control, in particular, the opening and the closing of the tailgate 10. This system can operate thanks to the capacitive sensor 60 which makes it possible to detect a part of the body of a person 70.

When the measuring means 40 detects a variation of capacity corresponding to the realization of a particular pattern, it sends an instruction to a control unit 80 for actuating the opening of the tailgate 10. In other words, the control system of opening comprises the sensor 60 and the control unit 80 and has the actuator the embodiment of a particular pattern by a person 70.

According to the example of FIG. 12A, of which FIG. 12B represents the detail at the connection, the coating 30 is applied to the visible face 20 of the part 10. The coating 30 is covered with a second coating 100, such as than an anti-fouling varnish. According to this embodiment, the coating 30 may be a conductive decorative film.

As shown in Fig. 13, the aperture control system may operate by contact with a body part of a person 70 (one hand or one fingers) to achieve a predefined pattern.

When the measuring means 40 detects a change in the electrical charges of the coating 30 corresponding to the embodiment of the pattern, it sends an instruction to a control unit 80 for actuating the opening of the tailgate 10. According to an embodiment illustrated in FIG. 14, the face 20, which forms a first face of the part 10, is covered at least partially by the coating 30 and a second face 260 of the part 10 (corresponding to the internal face of the the part 10, which therefore corresponds to a non-visible face for an observer outside the vehicle) also comprises zones 270 covered by the coating 30. These zones 270 are arranged facing the coating 30 affixed to the face 20. When the finger approaches or comes into contact with the part 10 at a zone of the face 20 covered by the coating 30 and opposite one of the zones 270, the capacitor C1 at the level of the face 20 increases causing a variation of capacitance C3 at zone level 270. A measurement of the capacitance C3 is performed on each zone 270 simultaneously, which makes it possible to detect a pattern, for example a temporal pattern, on these zones and to compare this pattern with a predefined pattern. The use of these zones 270 makes it possible to amplify the capacitance variation and consequently to achieve better detection of a pattern.

The invention is not limited to the embodiments presented and other embodiments will become apparent to those skilled in the art. It is possible in particular that the part 10 is a mobile spoiler, or aerodynamic flaps ("active shutter").

List of numerical references

10: bodywork part

11: main body made of plastic

12: Tailgate opening skin

14: Tailgate opening lining

20: outer face of the body part

21: inner side of the bodywork part

22: Police plate area

30: coating

40: means for measuring a variation of an electrical parameter related to the coating 50: electrical potential of the earth

60: capacitive sensor

70: person or object

80: control unit

90: connecting means between the coating and the measuring means

100: other (s) coating (s)

110: coating forming an electromagnetic shield

120: spindle

130, 140: parts of the spindle

150: geographical ground

160, 170, 180: points of the geographical motif

190, 200, 210: connections between the points of the geographical pattern

215: rhythmic pattern

220, 230, 240, 250: contacts on the part

260: second face of the coin

270: areas of the second face of the part covered by the coating

Claims

claims

1. Body part (10) of a motor vehicle made of plastic material, characterized in that it comprises:

at least one face (20, 21) provided with a coating (30),

a means (40) for measuring a variation of an electrical parameter related to the coating 30, and

means (90) for connecting the coating (30) to the measuring means (40) for a variation of an electrical parameter related to the coating (30),

the coating (30) being able to adhere to the plastics material of the part (10), and has an electrical resistance of less than 20kΩ at 300K, preferably less than 5kΩ, more preferably less than 3kΩ,

the coating (30) and the measuring means (40) defining a capacitive sensor (60) capable of detecting at least one previously defined pattern (150, 215).

2. Part (10) according to the preceding claim, wherein the previously defined pattern (150, 215) is a rhythmic pattern (215), preferably composed of a series of contacts (220, 230, 240, 250) successive d a predefined duration.

3. Part (10) according to one of the preceding claims, wherein the previously defined pattern (150, 215) is a geographical pattern (150) composed of several points (160, 170, 180) interconnected during the realization of the pattern (150) or forming isolated key areas.

4. Part (10) according to the preceding claim, wherein the coating (30) contains electrically conductive fillers, chosen alone or in combination in the following group of charges: graphite, metals, such as copper, silver, iron, indium, graphite alloy and metal, carbon black.

5. Part (10) according to the preceding claim, wherein the coating (30) contains more than 10% by weight of conductive filler, preferably between 20% and 60% by weight.

6. Part (10) according to one of the preceding claims, wherein the coating (30) is selected from the following group of coatings: a body part paint; a primary; a base ; a varnish ; a metallic film; an electrically conductive substrate; an electrically conductive coating.

7. Part (10) according to one of the preceding claims, wherein the coating (30) is covered with at least one other coating (100) selected from the group of coatings following: an antifouling protection varnish, a base, a varnish of paint.

8. Part (10) according to one of the preceding claims, wherein the means connection pieces (90) are overmolded in the workpiece (10) or connected to a coating portion (30) extended on at least a portion of a non-visible face (21) of the workpiece (10).

9. Part (10) according to one of the preceding claims constituting an opening (10) of a motor vehicle, a bumper, a wing, a hood, a roof.

10. Part (10) according to one of the preceding claims, wherein the capacitive sensor (60) forms a body of a vehicle control system, such as an opening system of an opening (10), a control system of a light device, a control system of a sound device or a control system of an air conditioning control device inside the passenger compartment.

11. Part (10) according to the preceding claim, wherein the part (10) is a hatch type opening (10), the face (20, 21) of the part (10) comprises a covered plate plate area (22) by the coating (30).

12. Part (10) according to one of the preceding claims, wherein the measuring means (40) is a means for measuring the capacitance between the coating (30) and the electric potential of the earth (50).

13. Part (10) according to the preceding claim, wherein the coating (30) is covered with a plastic wall.

14. Part (10) according to one of the preceding claims, wherein the measuring means (40) is a means for measuring an electric charge variation of the coating (30).

15. Part (10) according to one of the preceding claims, wherein the face (20) of the workpiece (10) forms a first face of the workpiece at least partially covered by the coating (30) and a face (21). the part opposite the first face (20) comprises several areas (270) covered by coating (30) opposite the first face (20) covered by the coating (30).

16. Part (10) according to one of the preceding claims, wherein the face (20) of the part (10) is partially covered by the coating (30).