Spacer fabric

Abstract

A knitted spacer fabric has two transversely spaced knitted layers and first and second spacer yarns extending transversely between and connecting the knitted layers. Both knitted layers are formed by metal braid that is arranged such that laminar electrical and thermal conduction is provided by the metal braid in both knitted layers, and the first spacer yarns are also formed by metal braid.

Claims

1. A knitted spacer fabric having: two transversely spaced knitted layers each formed at least partially by metal-braid yarns; and first spacer yarns extending transversely between and connecting the knitted layers and formed by metal-braid yarns such that laminar and transverse electrical and thermal conduction is provided by the metal-braid yarns of the knitted layers and of the spacer yarns.

2. The improved knitted spacer fabric defined in claim 1, wherein both knitted layers are composed entirely of the metal-braid yarns.

3. The improved knitted spacer fabric defined in claim 1 wherein each of the metal-braid yarns is formed by tinned strands of copper or a copper alloy.

4. The improved knitted spacer fabric defined in claim 1, wherein each of the knitted layers on the one hand and the spacer yarns on the other hand are formed with two needle bars.

5. The improved knitted spacer fabric defined in claim 1, further comprising: second spacer yarns formed by polymeric monofilament yarns.

6. The improved knitted spacer fabric defined in claim 5, wherein the monofilament yarns have a diameter of between 50 μm and 300 μm.

7. The improved knitted spacer fabric defined in claim 5, wherein the monofilament yarns are formed by polyester.

8. The improved knitted spacer fabric defined in claim 7, wherein the monofilament yarns are formed by polyethylene terephthalate.

9. The improved knitted spacer fabric defined in claim 1, wherein the metal-braid yarns forming each of the knitted layers and the first spacer filaments have between 5 and 15 strands each having a diameter of between 15 μm and 100 μm.

10. The improved knitted spacer fabric defined in claim 1, wherein the fabric has a thickness is between 2 mm and 20 mm.

11. The improved knitted spacer fabric defined in claim 1, wherein the fabric has a weight per unit area between 0.25 kg/m.sup.2 and 2.5 kg/m.sup.2.

12. Use of the knitted spacer fabric according to claim 1 as a heat conduction layer connected to an electrical component for heat removal.

13. The use defined in claim 12, wherein the knitted spacer fabric is arranged in a thermally conductive manner in a gap between a housing wall and the electrical component.

14. The use defined in claim 11, wherein the knitted spacer fabric is connected as a heat sink to an electronic component.

15. The use defined in claim 14, wherein fluid is flowed through the knitted spacer fabric.

16. The use defined in claim 15, wherein the fluid flow is effected by a fan.

17. The use defined in claim 11, wherein the knitted spacer fabric and the electrical component are integrally connected to one another.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

(2) FIG. 1 is a perspective view of a piece of the spacer fabric according to the invention;

(3) FIG. 2 is a large-scale edge view of the fabric;

(4) FIG. 3 is a vertical section through an assembly showing an application of the inventive spacer fabric; and

(5) FIG. 4 is a perspective view of another application of the inventive spacer fabric.

SPECIFIC DESCRIPTION OF THE INVENTION

(6) As seen in FIG. 1, a knitted spacer fabric has two knitted and generally planar or flat outer layers 1 and first and second spacer yarns 2a and 2b that extend transversely between and interconnect the knitted layers 1. Both knitted layers 1 and the first spacer yarns 2a are formed wholly of metal braid. This results in a three-dimensional, thermally and electrically highly conductive structure whose conductivity is ensured in the plane of the two knitted layers 1 and transversely by the first spacer yarns 2a in the direction of knit's thickness. The thermally and electrically conductive connection of the first spacer yarns 2a to the knitted layers 1 is achieved by using uncoated and uninsulated strands in the metal braid of the layers 1 and yarns 2a by having the yarns or strands of the metal braid angled as a result of stitching abut against one another.

(7) It can be seen particularly in FIG. 2 that the second spacer yarns 2b are formed by polymeric monofilament yarn. By virtue of the polymeric monofilament yarn, good elastic properties are achieved that keep the two knitted layers 1 spaced apart from one another.

(8) FIG. 1 shows how the preferably identically designed knitted layers 1 have openings 3 each formed by a plurality of stitches, thereby achieving an especially open and airy structure.

(9) The metal braid can have between 5 and 15 individual strands, for example seven here, whose diameter is typically between 15 μm and 100 μm, for example about 70 μm. Especially preferably, the metal braid is formed by individual tinned copper wires, resulting in especially good heat conduction at comparatively low production costs. The sheath of tin makes it easy to solder the strands of copper. The polymeric monofilament yarn forming the second spacer yarns 2b can be polyester, particularly polyethylene terephthalate (PET), and usually has a diameter of between 50 μm and 300 μm.

(10) The knitted spacer fabric illustrated in FIG. 1 is made by a total of six needle bars, namely two needle bars for the two knitted layers 1 and the spacer yarns 2a and 2b. The first spacer yarns 2a and the second spacer yarns 2b are therefore associated with different needle bars, so that full needle bars result in a ratio of the density of the spacer yarns 2a and 2b of 1:1.

(11) The thickness of the knitted spacer fabric can for example be between 2 mm and 20 mm.

(12) FIG. 3 shows the use of the above-described knitted spacer fabric as a heat conduction layer fitted to an electrical component 4a for the purpose heat dissipation. Specifically, the somewhat transversely compressible knitted spacer fabric 1 is fitted in a thermally conductive manner in a gap 5 between a normally conductive housing wall 6 and the electrical component 4a, so that different gap dimensions can be thermally bridged. The electrical component 4a can be a rechargeable battery module, a motor, or the like.

(13) FIG. 4 shows an alternative use of the knitted spacer fabric 1 according to the invention as a heat sink connected to an electronic component 4b. The knitted spacer fabric replaces largely massive, metallic heat sinks having ribs that are usually formed by injection molding or milling. In the illustrated embodiment, in order to flow air flow through knitted spacer fabric 1 as a heat sink, a fan 7 is provided that is mounted on the knitted spacer fabric 1 opposite the electronic component 4b. This then results in the additional advantage that the fan 7 is protected to a certain extent against shocks and impacts by the elastic properties of the knitted spacer fabric 1.

(14) The knitted spacer fabric 1 is integrally bonded at 8 to the electrical component 4b. Adhesive, a thermal paste, or a metallic solder can be used as a the connecting means 8. This results in the advantage that, in the case of a configuration of the metal braid formed by tinned strands, soldering with metallic solder is easily possible, with an especially reliable and durable connection being achieved that is both thermally and electrically conductive.