Heating structures for motor vehicles

Abstract

The invention relates to a heating structure (1), in particular for installation in a passenger compartment of a vehicle, the heating structure (1) comprising at least one resistive layer arranged to release heat when an electric current passes through the layer (4), the panel also comprising an electrode array (5), the electrode array comprising a plurality of contact electrodes (6) arranged to be in electrical contact with the resistive layer to allow an electric current to flow through the resistive layer.

Description

Technical Field

[0001] The invention relates to a heating structure, in particular for installation in a passenger compartment of a vehicle, the structure being in particular a radiant panel. Background Art

[0002] Typically, the radiation panel includes a plurality of electrodes designed to provide current to the conductive coating, thereby providing heat by the Joule effect. Reference may be made, for example, to document US 2016 / 0059669 describing such a radiation panel.

[0003] A radiant panel is a device that generally includes an electrical circuit designed to provide an electric current to resistive conductor elements, thereby providing heat using the Joule effect. These resistive conductor elements can be wire elements or surface coatings. According to existing literature, the conductive coating can be, for example, a paint layer containing carbon particles and / or metal particles. One of the problems currently found is that it is difficult to obtain uniform heating over the entire surface of the radiant panel, i.e., to make the heating temperature between different points on the surface of the radiant panel constant. Since the radiant panels are used to be arranged in different parts of the passenger compartment (roof lining, doors, pillars, glove box, etc.), this disadvantage is further complicated by the constraints of the geometric shape. Summary of the invention

[0004] The object of the present invention is to propose an improved radiant panel.

[0005] Therefore, the present invention is a heating structure, in particular for installation in the passenger compartment of a vehicle, the structure being in particular a radiation panel, the heating structure comprising at least one resistive layer, which is arranged to release heat when an electric current passes through the layer, the panel also comprising an electrode array, the electrode array comprising a plurality of contact electrodes, which are arranged to be in electrical contact with the resistive layer so as to allow an electric current to flow through the resistive layer, wherein at least some of the contact electrodes are arranged to have a variable spacing between consecutive electrodes.

[0006] As we all know, the heat power generated by the Joule effect depends on the power supply voltage U and the resistance R between the two electrodes (here, the two contact electrodes), and follows the following law: P = U 2 / R. The resistance R is proportional to the distance d between the two contact electrodes.

[0007] The applicant has found that the current consumption of each area of ​​the resistive layer between two consecutive contact electrodes results in a voltage drop along the distribution electrode and therefore along the contact electrode pair. Since the potential difference of these areas is associated with the power provided by this area, and this power follows the power formula P=U 2 / R, the heating capacity provided by the heating structure becomes smaller and smaller along the contact electrode pair. The present invention can counteract this phenomenon of uneven heating and provide uniform heating due to the mutual spacing between the contact electrodes, which is suitable for reducing the resistance between the two contact electrodes and thus having a uniform dissipated power as desired.

[0008] To obtain this uniformity, the invention allows using the same resistive coating or resistive layer of the same thickness, in particular the same conductivity. This allows maintaining a simple manufacturing process for the heating structure.

[0009] According to one aspect of the invention, at least some of the contact electrodes, in particular all contact electrodes of the electrode array, are parallel to each other.

[0010] According to one aspect of the invention, the electrode array comprises a distribution electrode arranged to conduct current from a power source to a contact electrode, several contact electrodes being connected to the same distribution electrode.

[0011] According to one aspect of the invention, at least one distribution electrode is rectilinear over at least a portion of its length and a contact electrode associated with the distribution electrode is connected to the distribution electrode, for example perpendicularly thereto.

[0012] Naturally, the distribution electrodes can take different forms, in particular curved forms with rounding. The distribution electrodes can be parallel to one another or not parallel to one another.

[0013] According to one aspect of the invention, the electrode array comprises at least two distribution electrodes which are parallel to each other over at least a portion of their length, and whose associated contact electrodes are arranged between the two distribution electrodes and alternately arranged at a mutual spacing which decreases as the voltage existing between the electrode pair decreases, thereby maintaining substantially uniform electrical power between the contact electrode pairs.

[0014] According to one aspect of the invention, the contact electrodes arranged between two distribution electrodes, which contact electrodes form part of the same contact electrode group, have only two spacing values ​​or at least three or more spacing values.

[0015] According to one aspect of the invention, the resistive layer is a layer deposited on the substrate, in particular by screen printing, the resistive layer extending in particular between two distribution electrodes associated with the set of contact electrodes.

[0016] According to one aspect of the invention, the resistive layer comprises in particular carbon.

[0017] According to one aspect of the invention, the electrodes are made of a conductive material, in particular a metal, such as an ink charged by conductive particles, in particular silver particles or copper particles. If necessary, the electrodes are metal adhesive tapes, for example made of copper. Where applicable, these electrodes can also be manufactured by depositing materials on a substrate.

[0018] According to one aspect of the invention, the resistive layer associated with the set of contact electrodes is a continuous layer or, as a variant, comprises a plurality of separate resistive elements forming this layer.

[0019] According to one aspect of the present invention, the contact electrodes of the same group have the same length.

[0020] According to one aspect of the invention, the heating structure comprises a substrate carrying a resistive layer and electrodes. 2 The substrate preferably has a thickness of less than 1 cm.

[0021] The heating structure is in particular in the form of one or more layers.

[0022] The invention also relates to a component of a motor vehicle passenger compartment, in particular a component integrated in a door, or in particular a component of an instrument panel, a footwell trim, a roof lining, an armrest, comprising a heating structure, in particular a radiant panel as described above.

[0023] According to one aspect of the invention, a passenger compartment component comprising a heating structure (e.g. a radiant panel) is arranged to be heated by thermal radiation (radiant panel) or by thermal conduction or thermal contact (contact heating structure) rather than by convection heating, e.g. heating by heat carried by moving air. In particular, no airflow passes through the heating structure to cool or heat the passenger compartment. Preferably, the panel is disconnected from the air circulation system.

[0024] If necessary, the vehicle's heating structure and HVAC (heating, ventilation and air conditioning) system can be controlled in a coordinated manner.

[0025] The component constitutes, for example, an element of a glove box or a door panel of a vehicle or an element of a roof of a vehicle.

[0026] The invention also relates to a heating structure having a resistive layer and electrodes for heating the resistive layer, the heating structure being designed to be integrated in a passenger compartment component comprising a decoration visible from the interior of the passenger compartment, for example a decorative element of the passenger compartment, such as fabric, leather or an aesthetic covering.

[0027] The present invention also relates to a heating structure, which is particularly intended to be installed in a passenger compartment of a vehicle, the heating structure being particularly a radiation panel, the heating structure comprising at least one resistive layer, which is arranged to release heat when current passes through the resistive layer, the heating structure also comprising an electrode array, which comprises a plurality of contact electrodes, which are arranged to be in electrical contact with the resistive layer to allow current to flow through the resistive layer, wherein at least some of the contact electrodes are arranged to have a variable spacing (Di) between consecutive electrodes, wherein the thickness of the resistive layer is greater than the thickness of at least some of the contact electrodes, in particular greater than the thickness of all the contact electrodes, so that the resistive layer at least partially covers the contact electrodes.

[0028] The invention is particularly advantageous because any local resistance in the circuit formed by the electrode and the resistive layer is a possible cause of hot spots which may result in power limiting, whilst the invention provides an improved bond between the contact electrode and the resistive layer.

[0029] The invention thus allows optimizing the contact pattern between the conductive contact electrode and the resistive layer of the radiant panel.

[0030] For reasons of production precision, the contact electrode and the resistor layer are formed, in particular, by depositing materials to form them separately; advantageously, the resistor layer material is covered on the contact electrode material.

[0031] The invention allows avoiding contact irregularities which could lead to local lack of electrical contact.

[0032] According to one aspect of the invention, contact electrodes are formed on a substrate, the thickness of these contact electrodes is measured in a direction locally perpendicular to the substrate, and the thickness of the resistive layer is also measured in a direction locally perpendicular to the substrate.

[0033] According to one aspect of the invention, each contact electrode comprises a face opposite to the substrate, and the resistive layer at least partially, in particular completely, covers the face opposite to the substrate.

[0034] According to one aspect of the invention, the thickness of the resistive layer covering the contact electrode is between 20% and 100% or 50% of the thickness of the contact electrode. For example, for an electrode thickness of 40 microns, the local thickness of the resistive layer covering the contact electrode is 8 microns.

[0035] According to one aspect of the present invention, the electrode has a substantially rectangular cross section, and the shape of the resistive layer in the region in contact with the electrode completely follows at least two vertical sides of the rectangular contour. For example, the resistive layer partially has a right-angled corner shape.

[0036] According to one aspect of the invention, the heating structure comprises a distribution electrode which also forms a contact electrode. For example, in this case, the resistive layer covers only a portion of the distribution electrode, but not the entire top side of the distribution electrode. Thus, the resistive layer may be in contact with only one edge of the electrode, but not with both longitudinal edges of the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] It should be understood that the above-mentioned features and configurations are by no means limiting. Further features, details and advantages of the present invention will become more apparent by reading the detailed description given below and several exemplary embodiments given by way of non-limiting indications, with reference to the accompanying drawings, in which:

[0038] Figure 1 is a schematic diagram of an exemplary embodiment of a radiation panel according to an exemplary embodiment of the present invention;

[0039] Figure 2 is a schematic diagram of components comprising a radiant panel of the present invention;

[0040] Figure 3 is a schematic diagram of a cross section of a radiant panel of the present invention; and

[0041] Figure 1 A radiant panel 1 forming a heating structure in the sense of the invention is shown, which radiant panel is designed to be installed in a passenger compartment 3 of a vehicle. DETAILED DESCRIPTION

[0042] The radiation panel 1 comprises a resistive layer 4 designed to release heat when an electric current passes through the resistive layer 4 .

[0043] The resistive layer 4 is, for example, an acrylic paint which is charged by conductive or semi-conductive particles. Such conductive charges are, for example, in the form of carbon or graphite flakes.

[0044] The panel 1 further comprises an electrode array 5 comprising a plurality of contact electrodes 6 arranged to be in electrical contact with the resistive layer 4 so as to allow current to flow through the resistive layer 4 .

[0045] These contact electrodes 6 are arranged with a variable mutual spacing D1 , D2 . . . Di between consecutive electrodes.

[0046] In the example described, the contact electrodes 6 are rectilinear and parallel to one another.

[0047] The electrode array 5 comprises distribution electrodes 8 arranged to conduct current to the contact electrodes 6, wherein one of these distribution electrodes 8 is connected to a power supply 9, for example a power supply of positive polarity. The other distribution electrode 8 is connected to the other polarity, for example ground.

[0048] The current thus enters the distribution electrode 8 which distributes the current to the contact electrode 6. The current then circulates in the resistive layer 4 before being collected by the contact electrode 6 connected to this further distribution electrode 8.

[0049] Several contact electrodes 6 are connected to the same distribution electrode 8 .

[0050] The distribution electrodes 8 are rectilinear over a portion of their length, or even over their entire length, and the contact electrodes 6 associated with these distribution electrodes 8 are connected perpendicularly to the associated distribution electrode 8 .

[0051] Here, the electrode array 5 includes two mutually parallel distribution electrodes 8, and its associated contact electrodes 6 are arranged between the two distribution electrodes 8 and are arranged alternately at intervals D1, D1...Di, which decreases as the voltage U1, U2...Ui existing between the paired electrodes 6 decreases, so as to maintain a basically uniform electric power between the contact electrode pairs.

[0052] The contact electrodes 6 arranged between two distribution electrodes 8 (these contact electrodes form part of the same contact electrode group 14 ) have a plurality of separation values ​​D1 , D2 . . . Di. In the example described, D1>D2>D3>D4, and U1>U2>U3>U4 are the voltages between the electrodes 6 .

[0053] The resistive layer 4 is a layer deposited on the substrate 16 in particular by screen printing, which resistive layer 4 extends in particular between two distribution electrodes 8 associated with a contact electrode set.

[0054] The electrodes 6 and 8 are made of an electrically conductive material, in particular a metal, such as a paint which is electrically charged by electrically conductive particles, in particular silver or copper particles.

[0055] In the example described, the resistive layer 4 associated with the contact electrode set is a continuous, substantially rectangular layer. Other shapes are naturally also conceivable.

[0056] The contact electrodes 6 in one and the same group 14 have the same length. As a variant, the electrodes 6 may have different lengths.

[0057] In an example not shown, several pairs of distribution electrodes 8 and then several groups 14 of contact electrodes 6 may be provided.

[0058] A passenger compartment component 19 of a motor vehicle, in particular a component to be integrated in a door, is provided with a radiant panel 1. Several components may be arranged in the passenger compartment.

[0059] The component 19 may comprise a decorative layer applied to the radiant panel. The decorative layer may for example be airtight, for example made of leather.

[0060] If desired, the distribution electrode 8 may have a more complex shape, for example with one or more rounded corners connecting rectilinear portions.

[0061] In the example described, all the interval values ​​Di of a group 14 are different. As a variant, some of the interval values ​​in the same group may be identical, not all of them being different.

[0062] The substrate may be, for example, a sheet or a cloth.

[0063] The contacting electrodes 6 and their associated distribution electrodes 8 are arranged in the manner of a meshing comb.

[0064] In one variant, the heating structure is used in a component of the passenger compartment as a passenger armrest, wherein the structure can warm the passenger's arm by thermal contact.

[0065] Figure 3 A cross section in the thickness direction of the radiation panel 1 is shown.

[0066] At least locally, the thickness of the resistive layer 4 is greater than the thickness of the contact electrodes 6 , so that the resistive layer 4 completely covers these contact electrodes 6 .

[0067] The contact electrodes 6 are formed on the substrate 16 , the thickness of these contact electrodes 6 being measured in a direction locally perpendicular to said substrate 16 , and the thickness of the resistive layer 4 being also measured in a direction locally perpendicular to the substrate 16 .

[0068] Each contact electrode 6 comprises a face 18 opposite to the substrate 16 , and the resistive layer 4 completely covers the face 18 opposite to the substrate.

[0069] The thickness d of the resistive layer 4 covering the contact electrode 6 is between 20% and 100% or 50% of the thickness e of the contact electrode 6. For example, for a contact electrode thickness of 40 microns, the local thickness d of the resistive layer 4 covering the contact electrode 6 is 8 microns.

[0070] The electrode 6 has a substantially rectangular cross section, and the shape of the resistor layer 4 in the region in contact with the electrode completely follows at least two vertical sides of the rectangular shape. For example, the resistor layer 4 partially has a right-angled corner shape.

Claims

1. A heating structure (1) for installation in a passenger compartment of a vehicle, the heating structure (1) comprising at least one resistive layer, the resistive layer being arranged to release heat when an electric current passes through the resistive layer (4), the structure further comprising an electrode array (5), the electrode array (5) comprising a plurality of contact electrodes (6), the plurality of contact electrodes (6) being arranged to be in electrical contact with the resistive layer so as to allow an electric current to flow through the resistive layer, wherein: The resistive layer at least locally has a thickness greater than the thickness of at least some of the contact electrodes so that the resistive layer at least partially covers these contact electrodes (6), wherein at least some of these contact electrodes are arranged to have a variable spacing (Di) between consecutive contact electrodes that decreases as the voltage between the contact electrode pairs decreases.

2. The heating structure according to claim 1, wherein: The contact electrodes (6) are formed on a substrate (16), the thickness of these contact electrodes being measured in a direction locally perpendicular to the substrate, and the thickness of the resistive layer being also measured in a direction locally perpendicular to the substrate.

3. The heating structure according to claim 2, wherein: Each of the contact electrodes (6) comprises a face opposite to the substrate, and the resistive layer at least partially covers the face (18) opposite to the substrate.

4. The heating structure according to claim 3, wherein: The thickness (d) of the resistance layer (4) covering the contact electrode is between 20% and 100% or 50% of the thickness (e) of the contact electrode.

5. The heating structure according to claim 4, wherein: The contact electrode (6) has a cross section with a substantially rectangular outline, and the shape of the resistive layer in the area in contact with the contact electrode completely follows at least two vertical sides of the rectangular outline.

6. The heating structure according to any one of claims 1 to 5, wherein: The electrode array (5) comprises a distribution electrode (8) arranged to conduct current from a power source to the contact electrodes, several contact electrodes being connected to the same distribution electrode.

7. The heating structure according to any one of claims 1 to 5, wherein: The resistance layer (4) is a layer deposited on the substrate by screen printing.

8. The heating structure according to claim 1, wherein: The heating structure is a radiant panel.

9. The heating structure according to claim 1, wherein: The resistive layer has at least partially a thickness that is greater than a thickness of all the contact electrodes.

10. The heating structure according to claim 3, wherein: The resistive layer completely covers the face (18) opposite to the substrate.

11. The heating structure according to claim 7, wherein: The resistive layer extends between two distribution electrodes associated with the contact electrode set.

12. A component (19) of a passenger compartment of a motor vehicle, comprising a heating structure as claimed in any one of the preceding claims.

13. Component (19) for a passenger compartment of a motor vehicle according to claim 12, wherein: The component is a component to be integrated in a door of the vehicle.

14. A component (19) for a passenger compartment of a motor vehicle according to claim 12, wherein: The component forms an element of a glove box or a door panel of a vehicle.

Images