DEVICE, SUPPLY LINE FOR A DEVICE OF THIS TYPE, SENSOR LINE, AND TORSION MEASUREMENT METHOD

Abstract

A device has two machine parts that are movable relative to one another and are connected to each other by a supply line along which a sensor line is mounted for measuring torsion of the supply line. The sensor line is connected to a measurement unit which is configured in such a way that an electrical parameter of the sensor line is measured, the torsion being ascertained using the parameter.

Claims

1. A device, comprising: a supply line having a sensor line for measuring a torsion of said supply line; two machine parts being movable relative to each other and connected to each other by said supply line; and a measuring unit connected to said sensor line, said measuring unit being formed in such a way that an electric parameter of said sensor line is measured and that conclusions about the torsion are drawn by means of the electric parameter.

2. The device according to claim 1, wherein said sensor line is configured to be mechanically robust for multiple measurements of the torsion.

3. The device according to claim 1, wherein said sensor line has two conductors, forming a conductor pair, and the electric parameter is a capacitance of said conductor pair.

4. The device according to claim 3, further comprising a soft material, which is compressed or widened in an event of torsioning of said sensor line, and is disposed between said two conductors.

5. The device according to claim 4, wherein said soft material has a Shore-A hardness in a range from 10 to 30.

6. The device according to claim 3, further comprising an insulating material and said two conductors are jointly embedded in a profile made of said insulating material and are spaced apart relative to each other by means of said insulating material.

7. The device according to claim 3, wherein said two conductors are each formed as coaxial conductors.

8. The device according to claim 3, wherein said sensor line has a common shielding surrounding said two conductors.

9. A supply line, comprising: a plurality of supply strands; and a sensor line for measuring a torsion of said supply line, wherein the torsion can be determined by using an electric parameter of said sensor line, said sensor line having two conductors, forming a conductor pair, and the electric parameter is a capacitance of said conductor pair.

10. A sensor line for measuring torsion of a supply line, wherein the torsion can be determined by using an electric parameter of the sensor line, the sensor line comprising: two conductors, forming a conductor pair, and the electric parameter is a capacitance of said conductor pair.

11. A method for measuring a torsion, which comprises the steps of: providing a sensor line having two conductors, forming a conductor pair, and the conductor pair having an electrical parameter being a capacitance; measuring the electrical parameter; and determining the torsion of the sensor line based on the electrical parameter.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0031] FIG. 1 is an illustration of a device having a supply line and a sensor line; and

[0032] FIG. 2 is an end view of the sensor line.

DETAILED DESCRIPTION OF THE INVENTION

[0033] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a device 2 which, here, is a robot. The device 2 has two machine parts 4, 6, here a base 4 and a manipulator 6. The machine parts 4, 6 are connected to each other by a supply line 8. In order to transmit energy, data, signals and/or working media, the line 8 usually has multiple supply strands, in particular different types of supply strands not illustrated in more detail here, in the form of electric, hydraulic or pneumatic lines, etc. In FIG. 1, by means of the supply line 8, for example control signals are transmitted from the base 4 to the manipulator 6. In a variant not shown, the two machine parts 4, 6, are for example, a vehicle and an electric charging station, and the supply line 8 is a charging cable for charging an energy store of the vehicle.

[0034] The machine parts 4, 6 are movable relative to each other and, accordingly, the supply line 8 is also to be movable as flexibly as possible. As a result, under certain circumstances complex mechanical loadings of the supply line 8 result, in particular including torsion, i.e. rotation. The torsion of the supply line 8 is determined by a sensor line 10, which is part of the supply line 8 and as a result is coupled mechanically to the supply strands. In the event of torsion of the supply line 8, the sensor line 10 is accordingly likewise rotated. The sensor line 10, together with the further supply strands, is preferably surrounded by a common outer sheath of the supply line 8 or, alternatively, is also fitted to the outside of such an outer sheath or else to a supply strand.

[0035] The sensor line 10 itself serves as a sensor, specifically as a torsion sensor, so that torsion between the two machine parts 4, 6 can be determined not just point by point but along the entire supply line 8. The sensor line 10 has transmission properties which depend on torsion of the sensor line 10. These transmission properties are characterized by at least one electric parameter, which is measured by a measuring unit 11. For this purpose, a test signal is fed into the sensor line 10 by the measuring unit 11 and, in particular, the change in the test signal on account of changed transmission properties is examined.

[0036] One exemplary embodiment of the sensor line 10 is illustrated in FIG. 2 in cross section at right angles to the longitudinal direction of the sensor line 10. The latter has two conductors 12, by means of which the measurement of the torsion is carried out. The two conductors 12 are spaced apart from each other at a spacing A. In the event of torsion of the sensor line 10, the two conductors 12 are rotated relative to each other, and the spacing A is changed. Starting from two parallel conductors 12, the spacing A is reduced. In one variant, the two conductors 12 are already stranded with each other in an initial position, so that torsion in one direction effects a reduction in the spacing and torsion in another direction an enlargement in the spacing. The two conductors 12 are embedded in a profile 14 which has a core element 16. The core element 16 is arranged between the conductors 12 and predefines the spacing A. In order to permit a change in the spacing A, the core element 16 is made of a soft and thus deformable material. As a result, the core element 16 can be compressed or pulled apart.

[0037] The torsion measurement is based on the finding that the two conductors 12 form a capacitor with a capacitance which depends on the spacing A and thus on the torsion. Accordingly, the measuring unit 11 is then expediently formed as a capacitance measuring unit and measures the capacitance of the conductor pair as an electric parameter. With the aid of the measured capacitance, the torsion is then determined.

[0038] The sensor line 10 of FIG. 2 additionally has a shielding 18, which surrounds the two conductors 12 and shields them from disruptive influences from outside. A line sheath 20 is arranged around the shielding 18. The conductors 12 are each surrounded by an insulating sheath 22. In a variant not shown, the conductors 12 are not each surrounded by an insulating sheath 22. In a variant likewise not shown, the two conductors 12 are formed as coaxial conductors and then, alternatively or additionally to the shielding 18, each have their own shielding.