Laminated conductor element for the manufacture of a heating system and helicopter blade that uses this

Description

technical field

[0001] The present invention relates to the technical field of conductive elements for the realization of a heating system, in particular for use of said conductive element in a de-icing system, and more particularly a de-icing system installed in a helicopter blade. Previous art

[0002] WO 96 / 07185 A1 describes a method for manufacturing a conductive component comprising a sheath of electrically insulating material, said sheath comprising at least two longitudinally extending conductive elements bordered on both sides by neutral zones not enclosing conductive elements, said conductive elements being arranged lengthwise in channels parallel to each other, the method comprising steps of: continuously extruding two strips of electrically insulating material and superimposing them one on top of the other and on both sides of the conductive elements.

[0003] Conductive components for the production of heating systems have the advantage of being able to be integrated into many mechanical devices, in order to combat frost.

[0004] These conductive components include, for example, metal braids surrounded by a sheath made of electrically insulating material.

[0005] The heating system is achieved by a plurality of metal braids connected to an electrical circuit, which heats the metal braids by Joule effect.

[0006] Document EP2781693 is known, which describes a conductive element for the implementation of a heating system, in particular for use of said conductive element in a de-icing system installed in a helicopter blade, comprising: an insulating sheath made of thermoplastic material defining two zones comprising at least one protruding metal braid; a neutral zone separating the two zones of the insulating sheath; and the metal braids are arranged along the length of the insulating sheath and parallel to each other.

[0007] Thus, the conductive element is more easily integrated into a helicopter blade without creating deformations or protruding elements on the blade, which improves the efficiency of the de-icing system.

[0008] However, such an organ can still be improved in terms of manufacturing process, particularly to improve the homogeneity of the thickness of the organ, but also of the heating surface. Description of the invention

[0009] One of the aims of the invention is therefore to propose a manufacturing process for a conductive element for a heating system which is controlled to obtain a conductive element which provides a uniform distribution of heat diffusion, while allowing its integration, in particular in a helicopter blade, without harming the general design of the heating system.

[0010] Furthermore, another objective of this invention is to provide a method for manufacturing a conductive component quickly, reliably and cheaply.

[0011] To this end, a method has been developed for manufacturing a conductive component for the production of a heating system comprising a sheath made of electrically insulating material, said sheath comprising at least two conductive elements extending longitudinally and bordered on both sides by neutral zones not enclosing conductive elements, said conductive elements being arranged along the length in channels parallel to each other.

[0012] According to the invention, the method according to claim 1 comprises steps consisting of: continuously extrude two strips of electrically insulating material, and superimpose them on each other and on either side of the conductive elements, particularly at the exit of an extruder, and laminate the neutral areas, which allows the two strips to be glued together and to form channels in which the conductive elements are placed.

[0013] In this way, the thickness of the heating system is better controlled, facilitating its integration into a mechanical device, such as helicopter blades. Furthermore, the distribution and distance between the conductive elements are also better controlled, which improves the system's heating efficiency through better distribution and positioning of the conductive elements.

[0014] Furthermore, the process according to the invention makes it possible to produce a continuously conductive element reliably and inexpensively.

[0015] The conductive element obtained according to the invention can be delivered as is, or, according to a preferred embodiment, the ends of the conductive elements are stripped, in particular to carry out, if necessary, the shaping of the conductor or to connect two conductors together, in order to allow the connection of the ends of the conductive elements with metallic connectors.

[0016] According to the invention, the neutral zones are rolled by at least as many rollers as there are neutral zones, for example the rollers are positioned in support, strips of electrically insulating material, and in counter-support against a conveyor belt.

[0017] This allows for easy adaptation to variations in the width of conductive elements, as well as to differences in pitch between two conductive elements, whether on the same conductive component or on two different conductive components manufactured one after the other on the same production line. The process according to the invention is therefore flexible and easy to implement.

[0018] In another embodiment, the neutral zones are laminated by two sets of rollers positioned on either side of the strips of electrically insulating material, counter-supporting each other.

[0019] Preferably, the rollers have widths corresponding at most to the width of the neutral zones so as not to crush the conductive elements, of course and without leaving the scope of the invention the rollers can be thinner than the width of the neutral zones, or wider if it is a question of rolling peripheral neutral zones.

[0020] According to a particular embodiment, and in order to facilitate the electrical connection of the conductive element, the bare ends of the conductive elements are bent.

[0021] In a particular embodiment, the bare, possibly curved, ends of the conducting element are coated with an electrically insulating material presented in ribbon and spiraled around said bare ends.

[0022] The conductive element is not limited in the number of conductive elements; preferably it comprises 5 to 9 conductive elements which may be of any suitable type, for example in the form of metal braids or metal ribbons, in particular of copper or aluminum or any other suitable material.

[0023] The invention also relates to a conductive element according to claim 8 obtained directly by the process according to the invention, and to a helicopter blade according to claim 9 in which at least one conductive element according to the invention is embedded in its thickness. Brief description of the drawings

[0024] Other advantages and features will become clearer from the following description, given by way of non-limiting example, of the component according to the invention, based on the accompanying drawings in which: [ Fig. 1 ] is a top-view representation of the conductive element for implementing a heating system according to the invention. Fig. 2 ] is a cross-section of the conducting organ at the level of a conducting element. Detailed description of the invention

[0025] With reference to figures 1 and 2The present invention relates to a method for manufacturing a conductive element (1) for a heating device comprising an electrically insulating sheath (2). The sheath is made of any suitable material, such as polyvinyl chloride, thermoplastic, and preferably thermoplastic elastomer or thermoplastic copolyester.

[0026] The sheath (2) comprising at least two conductive elements (3) extending longitudinally and bordered on both sides by neutral zones (4) not enclosing conductive elements (3).

[0027] The conductive elements (3) are arranged lengthwise in channels (5), parallel to each other.

[0028] The manufacturing process for the conductive element comprises steps consisting of continuously extruding two strips (20a, 20b) of electrically insulating material. These strips (20a, 20b) are electrically insulating and capable of dissipating the heat generated by the Joule effect. These two strips (20a, 20b) are superimposed one on top of the other and on either side of the conductive elements (3) in order to completely surround said conductive elements (3).

[0029] Furthermore, to bond the two strips (20a, 20b), they are laminated between the conductive elements. In other words, only the neutral zones are laminated. This prevents the conductive elements (3) from moving laterally within the sheath (2), resulting in more uniform heat dissipation from the heating system.

[0030] Indeed, the lamination of the two strips (20a, 20b) makes it possible to create channels (5) in which the conductive elements (3) are positioned.

[0031] Thus, the neutral zones (4) are laminated by as many rollers (not shown) as there are neutral zones (4). These rollers are positioned against the neutral zones, for example, counter-supported against a conveyor belt or against other rollers. Lamination is performed at the extruder outlet. The rollers have a width that is at most equal to the width of the neutral zones (4).

[0032] The conducting element (1) includes, for example, as illustrated figure 1 , five conductive elements (3) positioned in five channels (5) and therefore includes six neutral zones (4) bordering on either side of the conductive elements (3).

[0033] The conductive elements (3) are of any suitable type, preferably flat metal braids made up of a plurality of copper or aluminum wires, or a mixture of the two metals, braided together. Other conductive elements may be considered without departing from the scope of the invention, such as conductive ribbons or strips.

[0034] The ends (31) of the conductive elements (3) positioned in the channels (5) of the electrically insulating sheath (2) are stripped to allow their connection with metallic connectors (not shown), and in a known manner, said metallic connectors are attached to an electrical circuit for the realization of the heating system.

[0035] In a preferred embodiment, the stripped ends (31) of the conductive elements (3) are bent to facilitate connection with the metal connectors.

[0036] The bare and bent ends (31) are preferably coated with an electrically insulating material presented in ribbon and spiraled around said bare and bent ends (31).

[0037] The different conductive elements (3) can thus be stripped, bent and possibly coated with electrically insulating material, in different places, which makes it possible to obtain different lengths of the conductive elements (3).

[0038] The conductive element (1) obtained directly by the process according to the invention is very thin, preferably less than 10 mm in order not to impair the efficiency of the heating system, particularly when the latter is installed in a mechanism.

[0039] According to a preferred but non-limiting use of the conducting element (1) according to the invention, the latter is integrated into the thickness of a helicopter blade (not shown).

[0040] The illustrative conductive element (1) comprises 5 metallic braids held and positioned parallel to each other and enables the implementation of an efficient de-icing system for the helicopter blade when the ends (31) stripped, bent and spirally coated with electrically insulating material are connected with metallic connectors which are themselves connected with an electrical circuit.

[0041] The neutral zones (4) allow each metal braid to be electrically isolated in order to obtain uniform heating of the blade but also allow the conductive element (1) to include areas of facilitated deformation in order to follow the profile of the helicopter blade.

Claims

1. Method for manufacturing a conductive element (1) for producing a heating system comprising a sheath (2) made of electrically insulating material, said sheath (2) comprising at least two conductive elements (3) extending longitudinally and bordered on either side by neutral zones (4) not containing conductive elements (3), said conductive elements (3) being arranged along the length in channels (5) parallel to one another, the method comprising steps consisting in: - continuously extruding two strips (20a, 20b) of electrically insulating material and superposing them on one another and on either side of the conductive elements (3); and - laminating the neutral zones (4); characterized in that the neutral zones (4) are laminated by at least as many rollers as there are neutral zones (4).

2. Method according to claim 1, characterized in that the ends (31) of the conductive elements (3) are stripped in order to allow their connection with metallic connectors.

3. Method according to claim 1, characterized in that the neutral zones (4) are laminated by two sets of rollers positioned on either side of the strips, in abutment against each other.

4. Method according to any one of claims 1 to 3, characterized in that the rollers have widths corresponding at most to the width of the neutral zones (4).

5. Method according to claim 2, characterized in that the stripped ends (31) of the conductive elements (3) are bent.

6. Method according to claim 2 or 5, characterized in that the stripped ends (31), optionally bent, of the conductive elements (3) are coated with an electrically insulating material in tape form and spirally wound around said stripped ends (31).

7. Method according to any one of the preceding claims, characterized in that the conductive elements (3) are in the form of metallic braids or metallic strips.

8. Conductive element (1) obtained according to the method of any one of the preceding claims, comprising a sheath (2) made of electrically insulating material, said sheath (2) comprising at least two conductive elements (3) extending longitudinally and bordered on either side by neutral zones (4) not containing conductive elements (3), said conductive elements (3) being arranged along the length in channels (5), characterized in that at least two conductive elements (3) have different widths.

9. Helicopter blade, characterized in that it comprises at least one conductive element (1) according to claim 8, embedded within its thickness.