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AT-413761-B - METHOD FOR MEASURING THE THICKNESS OF THE ISOLIER LAYERS OF AN ELECTRIC FLAT LINE AND ARRANGEMENT THEREFOR

AT413761BAT 413761 BAT413761 BAT 413761BAT-413761-B

Inventors

  • HERRMANN KURT DIPL ING
  • LADNER FRANZ DIPL ING

Assignees

  • GEBAUER & GRILLER

Dates

Publication Date
20060515
Application Date
20031016
Priority Date
20031016

Claims (5)

  1. 4 AT 413 761 B conductor formed group, which also has a capacity is charged as long until the comparator circuit 8 responds. Thereafter, the second switch 72 is again folded over, whereby the group formed by the metallic conductors 10, the upper insulating layer 11 and the roller 20 is discharged. The charging and discharging cycle can be performed once or 5 times. The respective time periods of the charging and discharging operations are measured by the measuring and control circuit 6. Since, on the one hand, the charging times are directly proportional to the capacitance values, and on the other hand, since the capacitance values are indirectly proportional to the thicknesses of the insulating layers 11 and 12, the ratio of the thicknesses of the two insulating layers 11 and 12 can be determined. Because the flat cable 1 bears against the two rollers 40 and 20 over a large angle, a high measuring accuracy is achieved. The accuracy of measurement is also very high, because the tolerances of the current source, further the source for the reference potential and also the comparator circuit in the measurement is not received, since only their respective ratios are measured. The measurement result is used for the control of the manufacturing process with respect to the thicknesses of the two insulating layers 11 and 12 of the flat conductor 1. 20. A method for measuring the thicknesses of the insulating layers (11, 12) located on the two sides of a flat electrical cable (1), the outer sides of the two insulating layers (11, 12) being along two electrodes (2, 3) associated therewith 4) and the capacitance values between the electrical conductors (10) and the two electrodes (2,4), which are a measure of the thicknesses of the insulating layers (11,12), are determined and compared with each other, characterized the two electrodes (2, 4) are charged with constant current to a potential predetermined relative to earth or reference potential 30, that the time periods occurring to reach this potential are measured and compared with each other, and that the electrodes (2, 4) in each case after reaching of the reference potential are discharged.
  2. 2. The method according to claim 1, characterized in that the two electrodes 35 (4.2) by rollers (40,20) are formed, around which the two outer sides of the insulating layers (12,11) of the flat cable (1) are guided and each of which is supplied with electric current.
  3. 3. The method according to any one of claims 1 and 2, characterized in that the 40 flat cable (1) is successively guided over two rollers (40,20), that the two outer sides of the insulating layers (12,11) to each one of Rolling (40,20) come to rest, that the two rollers (20,40) are applied as long electrical power until they have reached reference to ground or a reference potential, that the periods of time to reach the reference potential measured 45 and with each other be compared and that the rollers (40,20) are discharged after reaching the reference potential Refe.
  4. 4. Arrangement for carrying out the method according to one of the claims 1 to 3, characterized in that two rollers (40,20) are provided, via which the flat cable (1) is guided in succession, that a current source (7) is provided, which can be applied to one of the two rollers (40, 20) via a first switch (71), that a measuring and control circuit (6) is provided, which by a second switch (72) each roller (40,20 ) is discharged after reaching a reference potential and by which the time periods until reaching the reference potential are measured 55 and compared with each other.
  5. 5 5 AT 413 761 B For 2 sheets Drawings 10 15 20 25 30 35 40 45 50 55

Description

2 AT 413 761 B The subject invention relates to a method for measuring the thicknesses of the insulating layers located on both sides of a flat electrical line, wherein the outer sides of the two insulating layers are guided along two associated electrodes and the capacitance value between the electrical conductors and the two electrodes. which are a measure of the thicknesses of the insulating layers, determined and compared. In the manufacture of flat electrical cables which consist of a plurality of band-shaped metallic flat conductors and insulating layers arranged on both sides of these conductors, it is necessary to ensure that the two insulating layers have approximately the same thicknesses. Taking into account the fact that on the one hand the thickness of the metallic flat conductors, which is held in very close tolerances, and on the other hand, the sum of the thicknesses of the two insulating layers surrounding them on both sides, it is sufficient, the ratio of the thicknesses of the two insulating layers and control deviations exceeding a predetermined value to control the manufacturing process such that the two insulating layers have approximately the same thicknesses. DE-A1 2921082 discloses a method according to which a high-frequency voltage is induced by means of a toroidal coil in a line passed through it and the capacitance of the insulation is measured by means of a bridge circuit. In order to allow the flow of current in the line, however, this must be grounded, which is why this known method requires a relatively complex measuring arrangement. The object of the present invention is therefore to provide a method by which a simplification in the measuring arrangement is achieved. According to the invention, this is achieved by charging the two electrodes with a constant current to a potential predetermined relative to earth or a reference potential, measuring and comparing the time periods occurring to achieve this potential, and that the electrodes each after reaching the reference potential be discharged. Due to this method, the grounding conditions are not relevant if they remain unchanged during a measurement cycle. This insensitivity to the grounding conditions ensures optimum results in determining the thicknesses of the two insulating layers. 35 Preferably, the two electrodes are formed by rollers around which the two outer sides of the insulating layers of the flat conductor are guided and which are each acted upon by electric current. In this case, preferably, the flat line is successively guided over two rollers, that the two outer sides of the insulating layers of each of 40 coming into contact with one of the rollers, the two rollers are so long acted upon by electric current until they are compared to ground or to a reference potential a predetermined Reference potential have been reached, the time periods are measured to reach the reference potential and compared with each other and the rollers are discharged after reaching the reference potential. 45 According to a preferred arrangement for carrying out this method, two rollers are provided, over which the flat cable is guided in succession, a current source is provided which can be applied via a first switch either to one of the two rollers, a measuring and control circuit is provided which by a second so switch discharges each roller after reaching the reference potential and by which the time periods are measured until reaching the reference potential and compared with each other. The method according to the invention is explained in more detail below with reference to an embodiment shown in the drawing. Show: 3 AT 413 761 B 1, Fig.la a measuring arrangement in a schematic representation for explaining the method according to the invention, in side view and in plan view, and Figure 2 shows an arrangement for carrying out the method according to the invention. In FIGS. 1 and 1 a, a flat electrical cable 1 is shown, which consists of four ribbon-like conductors 10 made of copper and these insulating layers 11 and 12 enclosing on both sides. In the production of this flat cable 1, which takes place by an extrusion process, it must be ensured that the two insulating layers 11 and 12 have approximately the same thicknesses. 10 In order to achieve this, a first electrode 2 assigned to the upper insulating layer 11 and a second electrode 4 assigned to the lower insulating layer 12 are provided along the movement path of the flat conductor 10 which is coated with insulating layers. Furthermore, a measuring device 3 is provided, by means of which the electrical capacitance occurring between the electrical conductors 10 and the first electrode 15 2 with the upper insulating layer 11 as dielectric is measured, and a measuring device 5 is provided, by which the voltage between the electrical conductors 10 and the second electrode 4 occurring electrical capacitance is measured with the lower insulating layer 12 as a dielectric. It