Conductor joint and conductor joint component

Abstract

A conductor joint for joining a copper conductor to a fiber-structured heating element whose dimensions are length (L)>>width (W)>>thickness (T), and which heating element comprises carbon fiber strands, wherein the copper conductor is transversely disposed to the longitudinal direction (L) of the heating element to form a layered structure in the thickness direction (T), on both sides of the heating element, the copper conductor comprising strands separable from each other. The strands of the copper conductor, the number and diameter of which are suitable for transferring a power of more than ten kW, are quantitatively substantially evenly distributed on both sides of the heating element, the strands are disposed in a planar manner in such a way that the strands substantially lie in one plane, adjacent to each other, and the ends of the strands extend, in the width direction (W) of the heating element, beyond the heating element, wherein the portions of the ends of the strands extending beyond the heating element overlap each other, and an electric joint is formed between the lateral faces of these overlapping strands.

Claims

1. A system comprising: a fiber-structured heating element; a copper conductor; and a conductor joint therebetween, wherein dimensions of the fiber-structured heating element being length (L)>>width (W)>>thickness (T), and which heating element comprises carbon fiber strands, wherein the copper conductor is transversely disposed relative to a longitudinal direction (L) of the heating element to form a layered structure in a thickness direction (T), on both opposing sides of the heating element, the copper conductor comprising copper strands separable from each other, wherein the copper strands of the copper conductor, a number and a diameter of which are configured to transfer electric power of more than ten kW, are quantitatively evenly distributed on both opposing sides and corresponding surfaces of the heating element, having a material including carbon fiber strands of the heating element in between, so that on each of said both opposing sides the strands distributed thereto extend along and cover the width (W) of the heating element, the strands on each side of said both opposing sides being further disposed in a planar manner in such a way that the strands lie in one plane, adjacent to each other, and the ends of the strands further extend on each of said both opposing sides, in a width direction (W) of the heating element, beyond the heating element, wherein portions of the ends of the strands extending beyond the heating element overlap each other, and an electric joint is formed between lateral faces of these portions of overlapping strands.

2. The system as defined in claim 1, wherein the strands of the copper conductor extend, at the ends of the strands, beyond the heating element by a distance, this distance being more than 10 times greater than the strand diameter (d).

3. The system as defined in claim 1, wherein the layered structure also comprises, on the both opposing sides of the strands of the copper conductor facing away from the heating element in the thickness direction (T), a strip of the heating element adapted to equalize the electric potential between the heating element and the copper conductor as well as to increase the conductive area between the heating element and the copper conductor.

4. The system as defined in claim 1, wherein the strands consist of a straight, unbraided and uninsulated copper wire.

5. The system as defined in claim 1, wherein the magnitude of the current transfer capacity is chosen to allow an electric power of dozens of kilowatts through the conductor joint.

6. The system of claim 5, wherein the number of strands needed is calculated by the following equation: n=k*4*A/d.sup.2 where A is the cross-sectional area of the copper conductor determined by how high a current transfer capacity is required, n is the number of strands, k is the strand number constant and d is a diameter of one strand.

7. The system of claim 1, wherein the number of copper strands needed is calculated by the following equation: n=k*4*A/d.sup.2 where A is an cross-sectional area of the copper conductor determined by how high a current transfer capacity is required, n is the number of copper strands needed, k is the strand number constant and d is a diameter of one strand.

8. The system according to claim 1, wherein the strands of the copper conductor are removably fixed to an auxiliary substrate on which the strands are disposed in a planar manner in such a way that the strands extend in one plane, adjacent to each other.

9. The system according to claim 8, wherein the auxiliary substrate includes an adhesive tape on which the strands are disposed in a planar manner in such a way that the strands extend in one plane, adjacent to each other.

10. The system as defined in claim 1, wherein the magnitude of the current transfer capacity is chosen to allow an electric power of 25 to 45 kW through the conductor joint.

11. The system as defined in claim 1, wherein the strands of the copper conductor extend, at the ends of the strands, beyond the heating element by a distance, this distance being more than 30 times greater than the strand diameter (d).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an embodiment of the conductor joint.

(2) FIG. 2 shows a partial width of a copper conductor.

DETAILED DESCRIPTION OF THE INVENTION

(3) In the following, the invention will be explained in more detail with reference to the accompanying drawings wherein FIG. 1 shows an embodiment of the conductor joint, and FIG. 2 shows a partial width of a copper conductor.

(4) FIG. 1 shows a conductor joint 1 for joining a copper conductor 2 to a fiber-structured heating element 3 whose dimensions are length L>>width W>>thickness T, and which heating element 3 comprises intersecting carbon fiber strands 30, wherein the copper conductor 2 is transversely disposed to the longitudinal direction L of the heating element 3 to form a layered structure in the thickness direction T, on both sides of the heating element 3, the copper conductor 2 comprising strands 20 separable from each other. The strands 20 of the copper conductor, the number and diameter of which are suitable for transferring a power of dozens kilowatts, such as 25-45 kW, are quantitatively substantially evenly distributed on both sides of the heating element 3, the strands 20 are disposed in a planar manner in such a way that the strands 20 substantially lie in one plane, adjacent to each other, and the ends 201 of the strands extend, in the width direction W of the heating element 3, beyond the heating element 3, wherein the portions of the ends 201 of the strands extending beyond the heating element 3 overlap each other, and an electric joint is formed between the lateral faces of these overlapping strands 20. In the inlet end of the copper conductor 2, the suitably spaced strands extending in one plane can be bundled up 23 and connected to a transmission cable by means of a conventional conductor joint (not shown). The layers are laminated or glued together during the manufacture, using a suitable method and materials. For a carbon fiber heating element, reinforced plastic construction methods, typically manual laminating and vacuum-bag curing, are used as the method. It is also possible to use other known laminating methods.

(5) In an embodiment, the strands 20 of the copper conductor 2 extend, at the ends 201 of the strands, beyond the heating element by a distance, this distance being more than 10 times greater than the strand diameter d, preferably more than 30 times greater than the strand diameter. This ensures, up to the end of the edge of the heating element 3, that the electric current is evenly transferred from the copper conductor 2 to the heating element 3, throughout the entire width W of the heating element 3. Preferably, the proportions length>>width>>thickness also apply to the conductor joint, the orientation just is transverse to the longitudinal direction compared to the corresponding dimensions of the heating element.

(6) The layered structure also comprises, on the side of the strands 20 of the copper conductor 2 facing away from the heating element 3 in the thickness direction T, a strip 31 of the heating element 3 adapted to equalize the electric potential between the heating element 3 and the copper conductor 2 as well as to increase the conductive area between the heating element and the copper conductor.

(7) FIG. 2 is a view of an embodiment, or, more particularly, a part of the embodiment, across a short width of the copper conductor 2 and the strands 20 thereof. The figure is intended to illustrate how some of the strands 20 can be attached to each other while others of the strands can be slightly detached from each other. The strands preferably consist of a straight, unbraided and uninsulated copper wire in order to avoid a weakened contact caused by strand bending. The easiest way of obtaining a desired very conductive joint is to use straight strands. FIG. 2 shows the diameter d of one strand which preferably is approximately 0.3 mm. The number of strands needed is calculated by the following equation: n=k*4*A/d.sup.2 where A is the cross-sectional area of the copper conductor determined by how high a current transfer capacity is required. The strand number constant k is based on experience on the number of strands needed, typically k=0.9-1.1. Further, the magnitude of the current transfer capacity is chosen to allow an electric power of dozens of kilowatts, such as 30 kW, through the conductor joint, also resulting in a reliable ability to withstand most lightning strikes.

(8) In an aspect of the invention, the invention also relates to a prefabricated conductor joint component for making a conductor joint according to the invention. Therein, the strands of the copper conductor are removably fixed to an auxiliary substrate, such as adhesive tape, on which the strands are disposed in a planar manner in such a way that the strands substantially extend in one plane only, adjacent to each other.

(9) The invention may be described with the following examples:

EXAMPLE 1

(10) A conductor joint for joining a copper conductor (2) to a fiber-structured heating element (3) whose dimensions are length (L)>>width (W)>>thickness (T), and which heating element (3) comprises carbon fiber strands (30), wherein the copper conductor (2) is transversely disposed to the longitudinal direction (L) of the heating element (3) to form a layered structure in the thickness direction (T), on both sides of the heating element (3), the copper conductor (2) comprising strands (20) separable from each other, characterized in that the strands (20) of the copper conductor (2), the number and diameter of which are suitable for transferring a power of more than ten kW, are quantitatively substantially evenly distributed on both sides of the heating element (3), the strands (20) are disposed in a planar manner in such a way that the strands (20) substantially lie in one plane, adjacent to each other, and the ends (201) of the strands extend, in the width direction (W) of the heating element (3), beyond the heating element (3), wherein the portions of the ends (201) of the strands extending beyond the heating element (3) overlap each other, and an electric joint is formed between the lateral faces of these overlapping strands (20).

EXAMPLE 2

(11) A conductor joint (1) as defined in example 1, characterized in that the strands (20) of the copper conductor (2) extend, at the ends (201) of the strands, beyond the heating element (3) by a distance, this distance being more than 10 times greater than the strand diameter (d), preferably more than 30 times greater than the strand diameter (d).

EXAMPLE 3

(12) A conductor joint (1) as defined in example 1, characterized in that the layered structure also comprises, on the side of the strands (20) of the copper conductor (2) facing away from the heating element (3) in the thickness direction (T), a strip (31) of the heating element (3) adapted to equalize the electric potential between the heating element (3) and the copper conductor (2) as well as to increase the conductive area between the heating element (3) and the copper conductor (2).

EXAMPLE 4

(13) A conductor joint (1) as defined in example 1, characterized in that the strands (20) consist of a straight, unbraided and uninsulated copper wire.

EXAMPLE 5

(14) A conductor joint (1) as defined in example 1, characterized in that the magnitude of the current transfer capacity is chosen to allow an electric power of dozens of kilowatts, such as 25 to 45 kW, through the conductor joint (1).

EXAMPLE 6

(15) A conductor joint (1) as defined in examples 1 and 5, characterized in that the number of strands (20) needed is calculated by the following equation: n=k*4*A/d.sup.2 where A is the cross-sectional area of the copper conductor determined by how high a current transfer capacity is required.

EXAMPLE 7

(16) A conductor joint component for making a conductor joint (1) according to example 1, characterized in that the strands (20) of the copper conductor (2) are removably fixed to an auxiliary substrate, such as adhesive tape, on which the strands (20) are disposed in a planar manner in such a way that the strands (20) substantially extend in one plane, adjacent to each other.