Positioning conductor in dual core cable
By using indirect measurement methods and reflection measurement technology, combined with an extrusion press and control unit, the problem of accuracy in conductor spacing measurement was solved, enabling efficient quality control in cable production and ensuring that the cables meet electrical characteristic specifications.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZUMBACH ELECTRONICS
- Filing Date
- 2024-06-14
- Publication Date
- 2026-04-14
Smart Images
Figure CN121866441A_ABST
Abstract
Description
[0001] Two-conductor insulated wires, also known as "two-core cables," are increasingly being used as a cost-effective solution for high-performance communication over shorter distances. A two-core cable consists of two conductors that run parallel to each other along the cable's length and are housed within an insulation material. Typically, the insulation material embedded in the conductors can be oval, dumbbell-shaped, dogbone-shaped, or figure-eight-shaped.
[0002] In many applications that use dual-core cables, such as high-performance computing and 5G data transmission, high-speed communication must be guaranteed over distances of less than a few meters.
[0003] To achieve the necessary transmission speed and quality, the manufacturing process must reliably produce cables within very strict specifications regarding materials, geometry, insulation performance, and shape stability. Preferably, these specifications should be continuously checked (online) during the manufacturing process, allowing for timely correction of deviations from the expected results, thus reducing waste and costs.
[0004] Specifically, specifications concerning geometry are critical to product quality because these specifications relate to numerous electrical characteristics, such as capacitance between conductors, which in turn affect crosstalk as well as signal transmission speed and quality. Relevant quantities include the spacing between conductors, the distance between two conductors and the insulators at both ends, or the distance between conductors and the top and bottom of the embedded material.
[0005] The spacing between two conductors is understood as the distance between them, i.e., the shortest distance between the surfaces of the two conductors. An alternative but equivalent metric is the pitch, which is the distance between the axes of the two conductors. Therefore, in all embodiments, pitch can be used as a substitute for spacing.
[0006] Measuring these quantities presents several challenges. The embedded material can be foam-like, containing numerous small gas-filled chambers, which poses significant difficulties for ultrasonic measurements because the ultrasound waves are absorbed and scattered too rapidly to achieve the necessary penetration. Furthermore, the embedded material can be opaque, making optical measurements (i.e., measurements using visible or infrared light) impossible. Moreover, the shape may vary for each production run. Generally, it is preferable to use measurement techniques suitable for the material used, i.e., optical measurements for transparent materials and, for example, ultrasonic measurements for opaque or light-sensitive materials.
[0007] Typically, ultrasound is used to measure the position of conductors in a two-core cable. As mentioned, this method is unsatisfactory in materials such as foam, where the ultrasonic signal is absorbed, thus other principles are necessary, such as X-rays. X-rays provide the necessary penetration; however, the use of X-rays poses certain health risks, thus requiring adequate protective measures and significantly increasing costs. Alternatively, terahertz signals are known to be used, which can also penetrate foam materials.
[0008] Preferably, distance measurements can also be performed using interferometry, sometimes referred to as optical interferometry. Optical interferometry is a technique used to obtain images of the subsurface of translucent or transparent materials. Similar to ultrasonic methods, signals reflected from within the material are processed to provide a cross-sectional image.
[0009] Direct measurement of the distance between two conductors is never straightforward. Optical interferometry, ultrasonic, and terahertz techniques have limited lateral resolution, which does not allow for precise measurement of the distance between two very close wires. Furthermore, the shape of the cable affects the path of optical interferometry, ultrasonic, or terahertz signals within the cable insulation. X-ray systems could potentially measure the distance between conductors directly, but this is not widely accepted in industry due to safety concerns and cost.
[0010] Therefore, there is a need to provide a method for measuring the spacing between conductors (wires) in a two-core cable that is accurate enough without involving unnecessary health risks and / or costs.
[0011] This problem is solved by the method according to claim 1. Furthermore, this problem is solved by the system according to claim 11.
[0012] Specifically, this problem is addressed by a method for determining the spacing (S) between at least a first conductor and a second conductor that are at least partially, preferably completely, embedded in the embedded material, the method comprising the following steps:
[0013] a) In a first direction, at least a first external dimension (d1) of a first conductor, preferably the diameter of the first conductor, and a second external dimension (d2) of a second conductor, preferably the diameter of the second conductor;
[0014] b) Measure the width (W) of the embedded material in the first direction;
[0015] c) In the first direction, measure the first distance (D1) between the nearest point of the outer perimeter of the embedded material and the first conductor, and the second distance (D2) between the nearest point of the outer perimeter of the embedded material and the second conductor, respectively.
[0016] d) The spacing (S) between the first conductor and the second conductor in the first direction is determined by subtracting the first distance, the second distance, the first outer dimension and the second outer dimension from the width according to the formula S=W-(D1+D2+d1+d2), and / or the pitch (P) between the first conductor and the second conductor in the first direction is determined according to the formula P=W-D1-D2-d1 / 2-d2 / 2.
[0017] The key idea of this invention is that the measurement of the spacing or pitch between conductors relies on indirect measurement. Further preferred is the use of essentially reflective measurement. Reflective measurement refers to a measurement in which a signal, after being transmitted, is reflected at least at the surface to be measured along the transmission direction, and the reflected signal is then detected.
[0018] In this sense, reflectance measurement can be understood as a measurement that primarily measures a specific distance along a predetermined direction. Specifically, reflectance measurement provides only very limited lateral resolution. The advantage of relying on reflectance measurement lies in the fact that optical interferometry, ultrasonic, and terahertz measurements offer only very limited lateral resolution, but are highly accurate for distance measurements along a predetermined axis. Therefore, by using only such reflectance measurements, the overall accuracy of determining the spacing between conductors can be improved without requiring more complex or expensive imaging techniques. In particular, known geometric features of the cable structure can be utilized to determine the spacing between conductors more accurately.
[0019] According to the present invention, only the distance between the outer perimeter of the embedded material and the nearest point on the outer perimeter of one of the conductors is measured at a time, avoiding the need for high lateral resolution, which is beneficial for point measurement, and preferably beneficial for reflection measurement.
[0020] These are performed in a first direction, which is substantially parallel to the spacing between the conductors. Preferably, the first direction can be a horizontal direction.
[0021] In this way, the known relationship between the total width (outer diameter) of the embedded material, the width (diameter) of the conductor in the first direction, and the spacing can be used to directly measure the spacing.
[0022] Clearly, direct measurement of the spacing between conductors using reflection measurements is (essentially) impossible because the conductors themselves obstruct "down-the-line" measurements. Terahertz measurements are obscured by the conductive material of the conductors. The difference in sound propagation characteristics between insulators and conductors makes direct measurement of the spacing using ultrasonic signals difficult. Alternatively, direct measurements can be performed from a "bird's-eye view," however this necessitates measurement methods with high lateral resolution, which suffer from the aforementioned drawbacks.
[0023] High accuracy can be achieved using only measurements along a first direction (i.e., reflection measurements) by indirectly measuring the spacing and / or pitch between conductors. Furthermore, accuracy is further improved by reducing the total distance of the measurement to be performed from the outer perimeter of the embedded material to the nearest point on the nearest conductor, as shorter measurement distances result in lower amounts of absorption and / or scattering. Specifically, the first and second distances correspond to the depths of the conductors from the cable surface on the two respective sides.
[0024] Then, the distance S between the two conductors can be calculated as follows:
[0025]
[0026] Alternatively, the so-called pitch, which is the distance between the axes of the two conductors, can be determined. For symmetrical conductors, the pitch can be calculated as...
[0027] .
[0028] The distance of the conductor from the upper and lower surfaces can be assessed by using reflection measurements of optical interferometry, terahertz, or ultrasonic signals, providing a sufficiently accurate estimate for the production process.
[0029] In a preferred embodiment, the spacing and / or pitch between the conductors will be between 0.010 mm and 2.000 mm, more preferably between 0.500 mm and 1.500 mm. The preferred accuracy for determining the spacing is between ±0.005 mm and ±0.010 mm.
[0030] In a preferred embodiment, the first external dimension and the second external dimension are preferably obtained by optical measurement and / or by specification before the conductor is embedded into the embedding material.
[0031] When determining the external dimensions of the first and second conductors optically or by specification, the spacing can be determined more quickly and accurately.
[0032] Specifically, optical measurement of the conductor's external dimensions (diameter) is highly efficient if the measurement is performed before the conductor is embedded in the embedding material.
[0033] Specifically, since the diameter of the conductor itself changes very little over the length of the wire, it can be assumed that the external dimensions of the conductor (which can be considered its diameter at least in the first direction) are known. The external dimensions of the conductor can be a priori by obtaining specifications from the conductor manufacturer, or by additional measurements, particularly optical measurements, of the diameters of the two conductors, preferably before extrusion (insulation) into the embedding material.
[0034] In a preferred embodiment, the conductors are rotationally symmetrical about their length, such that their external dimensions correspond to their diameters. The diameters are preferably between 0.200 mm and 0.500 mm, or more preferably between 0.250 mm and 0.405 mm.
[0035] In yet another preferred embodiment, the width (W) is measured optically.
[0036] Because the embedded material itself is open and accessible, optical determination of the width can be performed very quickly and accurately.
[0037] In a preferred embodiment, the width will be between 0.500 mm and 5.00 mm, more preferably between 1.000 mm and 2.000 mm, with a preferred accuracy of ±0.018 mm.
[0038] In this article, width refers to the (especially the largest) total diameter from one side of the perimeter of the embedded material to the other in the first direction.
[0039] According to a preferred embodiment, reflection measurement is used to perform the measurement of the first and / or second distance, preferably optical interferometry, ultrasonic measurement, or terahertz measurement.
[0040] Depending on the embedded material, different measurement techniques may be more or less sufficient, as the embedded material exhibits different absorption and scattering characteristics at different wavelengths and / or relative to different waveforms (acoustic / electromagnetic). Further preferred is the use of terahertz measurements for foam-like embedded materials, and otherwise optical interferometry or ultrasound. As previously mentioned, this is preferred because terahertz measurements have better penetration in foam-like materials.
[0041] According to yet another preferred embodiment, the measurement method can therefore be selected based on the expected size of the first and / or second distances, in particular to minimize absorption.
[0042] The method according to any one of the preceding claims, wherein all measurements are reflection measurements.
[0043] The use of reflectance measurement is advantageous, specifically if it is performed using optical interferometry, terahertz, or ultrasonic signals, because the requirement for lateral resolution is reduced. Further preferred is that, for all those distances that cannot or should not be determined by optical measurements from images or shadows, at least reflectance measurement should be relied upon, as such optical measurements provide better lateral resolution.
[0044] Another aspect of the invention is a method for producing a two-core cable comprising a first conductor and a second conductor at least partially, preferably completely, embedded in an embedding material, wherein the first and / or second conductor is positioned within the embedding material using the following steps:
[0045] a) Controlling, in a first direction, a first distance (D1) between the nearest point of the outer perimeter of the embedded material and the first conductor, and a second distance (D2) between the nearest point of the outer perimeter of the embedded material and the second conductor.
[0046] b) Controlling the third distance (T1) and / or the fourth distance (T3) between the nearest point of the width of the embedded material and the first conductor in the second direction, wherein the third distance and the fourth distance are measured from the opposite outer side of the first conductor;
[0047] c) Controlling the fifth distance (T2) and / or the sixth distance (T4) between the nearest point of the outer perimeter of the embedded material and the second conductor in the second direction, wherein the third distance and the fourth distance are measured from the opposite outer side of the second conductor;
[0048] Wherein the first and second directions are orthogonal to each other and orthogonal to the length direction of the two-core cable, the method further includes the following steps:
[0049] d) Determine the spacing (S) and / or pitch between the first and second conductors using the methods described above;
[0050] e) Adjust the settings of one or more of the first distance, second distance, third distance, fourth distance, fifth distance and sixth distance based on the spacing measured in step d) to preferably achieve a spacing and / or pitch that is closer to the predetermined spacing;
[0051] Steps a) through e) are repeated iteratively, preferably in real time.
[0052] In this way, indirect measurement of spacing can be used to create feedback loops to help meet quality standards throughout the manufacturing process.
[0053] Specifically, the ideal spacing between two conductors can be predetermined, and the measurement of the actual spacing between the conductors can be used to achieve the predetermined spacing online during production.
[0054] Generally, the conductor spacing and / or pitch will depend most directly on the first and second distances. Although the third to sixth distances also affect the spacing to some extent, this is usually negligible, such that the control feedback loop between the measured conductor spacing and the control of the first and / or second distances is sufficient to achieve the necessary quality control.
[0055] Once it is determined that the spacing deviates from the predetermined value by more than a given amount, the first and / or second distances can be appropriately changed in order to correct the spacing and / or pitch, preferably continuously during production.
[0056] The second direction is defined as a direction perpendicular to the first direction in a plane, the plane being normal to the length direction of the wire. Preferably, the second direction is a vertical direction. In other words, the first and second directions cross a plane normal to the length direction of the wire.
[0057] According to yet another preferred embodiment, the spacing (S) and / or pitch are adjusted to achieve a predetermined capacitance between the conductors.
[0058] Since the distance between conductors has a significant impact on the capacitance of a cable, manipulating the spacing to achieve the desired capacitance is a simple and easy method.
[0059] In yet another preferred embodiment, the embedding material is an insulating and / or foam-like material.
[0060] Such materials provide the necessary flexibility and insulation properties to withstand deformation while maintaining the insulation of the wires.
[0061] In yet another preferred embodiment, the method includes the step of measuring at least one of a third distance, a fourth distance, a fifth distance, or a sixth distance, preferably by optical interference and / or terahertz and / or ultrasonic signals, and controlling these distances to be closer to predetermined values.
[0062] By controlling the third, fourth, fifth, or sixth distance, the conductor can be more accurately centered in the embedded material, which increases the overall precision of the spacing between the two conductors.
[0063] In yet another preferred embodiment, the measurement result of at least one of the third, fourth, fifth, or sixth distances is used to determine the spacing (S) and / or pitch.
[0064] While the first and second distances generally have the greatest impact on the spacing and / or pitch between conductors, further improvements in accuracy can be achieved by incorporating a third, fourth, fifth, or sixth distance into the determination of the spacing. Generally, this will result in a horizontal phase deviation introduced in the second direction from that in the first direction between the two conductors. This can be easily achieved by applying the Pythagorean theorem. In these cases, it can be assumed that the first and second conductors are rotationally symmetric about their length axis such that the width in the second direction is equal to the width in the first direction, in order to find the shortest distance between two points on the first and second conductors.
[0065] The problem is also addressed by a system comprising an extruder, a measuring unit, and a control unit, wherein the control unit is configured to control the extruder based on measurement signals from the measuring unit to perform the methods described above.
[0066] In most applications, two-core cables are manufactured using extrusion technology. In these cases, the creative idea of indirectly measuring spacing and / or creating feedback loops can be employed by controlling the extrusion process. Specifically, the extruder can be configured to control first through sixth distances to place the conductors within the embedding material.
[0067] The measuring unit can then measure an appropriate distance to indirectly infer the spacing between the conductors. Furthermore, the measuring unit can transmit the measurement results to the control unit, which then determines the spacing. For this purpose, the control unit may include at least one processor. If the measured spacing deviates from the desired spacing, the control unit can adjust the extrusion settings to move the spacing closer to the desired value.
[0068] According to another preferred embodiment, the measurement unit includes one or more of the following devices: an optical measurement device (preferably a camera or laser scanner), an optical interferometric measurement device, an ultrasonic measurement device, a terahertz measurement device, and an X-ray imaging device.
[0069] Optical measuring devices can be used to obtain the width of the embedded material and / or the external dimensions of the conductor, while the remaining imaging techniques can be used to measure the first through sixth distances using reflected signals.
[0070] This problem is also addressed by a computer-readable medium configured to cause the processor of the control unit to control the system described above to perform the methods described above.
[0071] The invention is further described below with reference to the accompanying drawings.
[0072] Figure 1 The cross-section of a roughly elliptical two-core cable is shown.
[0073] Figure 2 A dumbbell-shaped or figure-eight-shaped two-core cable is shown.
[0074] Figure 3 A schematic representation of a system including an extruder, a measuring unit, and a control unit is shown.
[0075] Figure 1 A typical two-core cable 1 with an elliptical shape is shown. In the orientation shown, the first direction can be considered as the direction connecting the two conductors 2 and 3, which is essentially horizontal. Figure 1In the figure, the first conductor 2 and the second conductor 3 have been embedded within the embedding material 4. As shown, the first distance D1 corresponds to the depth of the first conductor 2 below the surface or outer perimeter of the embedding material 4. More specifically, the first distance D1 is measured in a first direction from the surface of the first conductor 2 to the nearest point on the outer perimeter of the embedding material 4.
[0076] Similarly, the second distance D2 measures the depth of the second conductor 3 below the surface or outer perimeter of the embedded material 4. More specifically, the second distance D2 measures the distance from the surface of the second conductor 3 to the nearest point on the outer perimeter of the embedded material 4 in the first direction. In this case, the nearest point is on the right side of the second conductor 3.
[0077] According to the invention, the distance S between the two conductors 2 and 3 can be measured indirectly as follows. The total width W of the embedded material (in the first direction) can be measured, preferably optically. Then, a first distance D1 and a second distance D2 can be measured, preferably using reflected signals (i.e., given the indicated orientation, from the left and right sides respectively). The first external dimension d1 of the first conductor 2 and the second external dimension d2 of the second conductor 3 (also in the first direction) can also be measured, particularly in advance, or obtained from the manufacturer's specifications. Since most conductors 2 and 3 will be rotationally symmetrical about their length axis, the first external dimension d1 and the second external dimension d2 (in the first direction) will typically coincide with the diameter of conductors 2 and 3.
[0078] It can be seen that the spacing S can be indirectly calculated using the formula S=W-(D1+D2+d1+d2). If the first conductor 2 and the second conductor 3 are not centered and / or positioned within the embedded material in the second direction, then the (vertical) displacement in the second direction (corresponding to...) Figure 1 The top / bottom directions (in the image) may have a small effect on the spacing S. For a generally symmetrical embedding perimeter, this will result in unequal ratios between the third and fourth distances T1 and T3, and the fifth and sixth distances T2 and T4. Typically, control over the third through sixth distances T1, T3, T2, T4 is sufficient to ensure the required accuracy of the spacing S. However, the calculation of the spacing S can be easily modified in a trigonometric manner to include these distances.
[0079] It can be assumed that the extruder 103, which can be used to produce dual-core cables, is able to control at least some of the first to sixth distances based on the input of the control unit 101.
[0080] Figure 2 It shows the relationship with Figure 1 They have essentially the same features, although the perimeter shape of the embedded material 4 is different.
[0081] Figure 3A schematic diagram of a system 100 according to the present invention is shown. A control unit 101 controls an extruder 103 to produce a two-core cable with a given configuration having first to sixth distances D1, D2, T1, T3, T2, T4. The resulting two-core cable is measured by a measuring unit 102 to obtain the necessary distance, and this distance is then fed back to the control unit 101. The control unit 101 then indirectly determines the spacing S according to the method of the present invention and, if necessary, adjusts the control settings of the extruder 103 to obtain the desired spacing S.
[0082] It should be noted that the purpose of this disclosure is to achieve the broadest possible scope of protection. In this regard, the disclosure included in the claims can also be specified by utilizing features described by other features (and not necessarily by including these other features). It is explicitly stated that parentheses and the term "in particular" are intended to emphasize the optionality of features in the corresponding context (conversely, this does not mean that a feature is considered mandatory in the corresponding context without such identification). The term "element" is preferably intended to characterize a corresponding coherent structure (or component) that can in turn be connected to at least one other structure (to form a possible monolithic and / or immovable integral structure), or that can be demarcated from all other structures. List of reference numerals
[0083] 1. Two-core cable
[0084] 2 First conductor
[0085] 3 Second conductor
[0086] 4. Embedded materials
[0087] W width
[0088] S-spacing
[0089] D1 First Distance
[0090] D2 Second Distance
[0091] T1 Third Distance
[0092] T3 Fourth Distance
[0093] T4 Fifth Distance
[0094] T2 Sixth Distance
[0095] d1 First external dimension
[0096] d2 Second external dimension
[0097] 100 System
[0098] 101 Control Unit
[0099] 102 Measurement Units
[0100] 103 Extruder
Claims
1. A method for determining a spacing (S) between at least a first conductor and a second conductor, the first conductor and the second conductor being at least partially, preferably completely, embedded in an embedding material, the method comprising the steps of: a) In a first direction, at least a first external dimension (d1) of the first conductor, preferably the diameter of the first conductor, and a second external dimension (d2) of the second conductor, preferably the diameter of the second conductor; b) Measure the width (W) of the embedded material in the first direction; c) In the first direction, measure the first distance (D1) between the nearest point of the outer perimeter of the embedded material and the first conductor and the second distance (D2) between the nearest point of the outer perimeter of the embedded material and the second conductor, respectively. d) The spacing (S) between the first conductor and the second conductor in the first direction is determined by subtracting the first distance, the second distance, the first external dimension and the second external dimension from the width according to the formula S=W-(D1+D2+d1+d2), and / or the pitch (P) between the first conductor and the second conductor in the first direction is determined according to the formula P=W-D1-D2-d1 / 2-d2 / 2.
2. The method of claim 1, wherein preferably the first external dimension and the second external dimension are obtained by optical measurement or by specification before the conductor is embedded in the embedding material.
3. The method according to claim 1 or 2, wherein the width (W) is measured optically.
4. The method according to any one of the preceding claims, wherein the measurement of the first distance and / or the second distance is performed using one of X-ray measurement, optical interferometry, ultrasonic measurement, or terahertz measurement.
5. The method according to any one of the preceding claims, wherein all measurements are reflection measurements.
6. A method for producing a two-core cable comprising a first conductor and a second conductor, wherein the first conductor and the second conductor are at least partially, preferably completely, embedded in an embedding material, wherein the first conductor and / or the second conductor are positioned within the embedding material using the following steps: a) Controlling, in a first direction, a first distance (D1) between the nearest point of the outer perimeter of the embedded material and the first conductor, and a second distance (D2) between the nearest point of the outer perimeter of the embedded material and the second conductor. b) Controlling the third distance (T1) and / or the fourth distance (T3) between the nearest point of the outer perimeter of the embedded material and the first conductor in the second direction, wherein, The third distance and the fourth distance are measured from the opposite outer side of the first conductor; c) Controlling the fifth distance (T2) and / or the sixth distance (T4) between the nearest point of the outer perimeter of the embedded material and the second conductor in the second direction, wherein the third distance and the fourth distance are measured from the opposite outer side of the second conductor; Wherein the first direction and the second direction are orthogonal to each other and orthogonal to the length direction of the two-core cable, the method further includes the following steps: d) Determine the spacing (S) and / or pitch (P) between the first conductor and the second conductor according to the method of claim 1; e) Adjust the setting of one or more of the first distance, the second distance, the third distance, the fourth distance, the fifth distance and the sixth distance based on the distance measured in step d) to preferably achieve a distance (S) and / or pitch (P) that is closer to the predetermined distance (S) and / or pitch (P). Steps a) through e) are repeated iteratively, preferably in real time.
7. The method according to any one of the preceding claims, specifically the method according to claim 6, wherein the spacing (S) and / or pitch (P) are adjusted to achieve a predetermined capacitance between the conductors.
8. The method according to any one of the preceding claims, specifically the method according to claim 6 or 7, wherein the embedded material is an insulating and / or foam material.
9. The method according to any one of the preceding claims, specifically the method according to claims 6 to 8, further comprising the following steps: Measuring at least one of the third, fourth, fifth, or sixth distances, preferably by optical interferometry, terahertz, and / or ultrasonic signals, and controlling these distances to be closer to predetermined values.
10. The method according to any one of the preceding claims, specifically the method according to claim 9, wherein the measurement result of at least one of the third distance, the fourth distance, the fifth distance, or the sixth distance is used to determine the spacing (S) and / or pitch (P).
11. A system comprising an extruder, a measuring unit, and a control unit, wherein the control unit is configured to control the extruder based on a measurement signal from the measuring unit to perform the method as claimed in any one of claims 6 to 10.
12. The system of claim 11, wherein the measuring unit comprises one or more of the following devices: an optical measuring device, preferably a camera or laser scanner, an optical interferometer, an ultrasonic measuring device, a terahertz measuring device, or an X-ray imaging device.
13. A computer-readable medium configured to cause a processor of a control unit to control the system according to claim 11 to perform the method according to claims 1 to 10.