JPH03170807A - Measurement of twisted pitch of electric wire and cable - Google Patents

Abstract

PURPOSE:To measure the twisted pitch by a method comprising steps of projecting light to a cable, photographing the reflecting light by a camera and reading the diameter of a strand. CONSTITUTION:In a strand producing apparatus 10, when a twisting device 11, a capstan 13 and a winder 14 are rotated, a strand 2 is twisted at a twisting port 12 to be a cable 1 which is subsequently wound up by the winder 14. Light sources 22, 23 illuminate the cable 1 immediately after the twisting port 12 and immediately before the winder 14, respectively. The surface of the cable 1 is photographed by cameras 20, 21. At this time, the voltage of output signals from the cameras 20, 21 becomes maximum at the light part of the strand 2, while it is minimum at the dark part of the strand 2. Continuous pulse signals are obtained by wave-forming the signals. The cycle of the pulse signals represents the twisted pitch of the cable 1. The thickness of one strand can be detected by adding the bit numbers at the light and dark parts. Accordingly, the twisted pitch can be continuously detected in a computing element 25 on the basis of signals inputted from the cameras 20, 21.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for measuring the twist pitch of electric wires and cables such as overhead power transmission lines and overhead ground wires.

(Prior art and problems to be solved) Electric wires and cables such as overhead power transmission lines and overhead ground wires are formed by twisting multiple strands together using a wire twisting machine, and when manufacturing such twisted wires, If the twist pitch is not constant, a phenomenon occurs in which weakly twisted areas swell after manufacturing (this is called ``laughing J''), resulting in a defective product.

Therefore, it is essential to measure the twist pitch in the wire twisting process to always maintain a constant twist pitch.

Therefore, conventionally, the twisting pitch of the cable itself in the wire stranding process was determined by pressing paper or the like against the longitudinal direction of the electric wire/cable (stranded wire traveling direction) to separate each strand of the cable. The distance between the wires is copied and the distance between the copied strands is measured using a contact method using a scale or the like.

However, measurement using such a contact method not only does not allow continuous online measurement, but also because the paper is pressed directly against the cable, etc., so the paper is easily soiled by oil etc. adhering to the surface of the cable. There are problems such as poor workability.

Also, how to determine the twist pitch using a camera.
As previously proposed, if the distance between the camera and the cable is close, the reliability of the image at both ends of the camera angle is low, and since the twist pitch is measured at only one location, There are problems in that it is difficult to understand pitch fluctuations and it is not possible to appropriately apply these fluctuations to the operating speeds of the stranding machine, capstan, and winding machine.

Furthermore, there are other problems such as it is not easy to adjust the operating speeds of the twisting machine, capstan, and winding machine in order to adjust the twisting pitch.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a method for measuring the twist pitch of electric wires and cables, which allows the twist pitch of electric wires and cables to be measured in a non-contact manner.

(Means for Solving the Problem) In order to achieve the above object, according to the present invention, light is irradiated onto an electric wire/cable formed by twisting a plurality of wires, and the light reflected from the cable is The wire diameter of each strand of the cable is read by taking an image with a camera, and the twist pitch is measured based on the read diameter of each strand.

(Function) In the wire/cable stranding process in which multiple strands of wire are twisted together using a wire twisting machine to form a shape, the wire/cable is irradiated with light, and the reflected light reflected from the surface is received to form the wire/cable.
The cable is imaged, the wire diameter of each strand is read from the captured image, and the pitch between each strand is detected from the read signals to measure the twist pitch. This makes it possible to continuously measure the twist pitch of electric wires and cables without contact.

(Example) An embodiment of the present invention will be described below based on the accompanying drawings.

Figures 1 to 3 show the twist pitch fi of the electric wire/cable (hereinafter simply referred to as "cable" for convenience of explanation) of the present invention.
The cable 1 is formed by twisting a plurality of wires 2 together, and a camera such as a video camera (hereinafter simply referred to as a "camera") is mounted directly above the cable 1.
) 3 is disposed, and a light source 4 is further disposed diagonally above the cable l. The optical axis of this source 4 is set at a predetermined angle θ, for example, 45° with respect to the optical axis of the camera 3.
The cable l is arranged at an angle of , and the light L is irradiated in the longitudinal direction of the cable l over a wider range than the angle of view of the camera.

The angle of view of the camera 3 is set within a range that allows the twisting pitch of the cable l to be clearly photographed in order to increase the reliability of images at both ends. That is, the wire diameter of the cable 1 is measured only at the center of the camera angle. Then, the measured wire diameter is calculated to a predetermined number, and the cable l
The twist pitch of the material is measured.

Incidentally, when the cable 1 is irradiated with the light L as shown in FIG. If it deviates slightly from the direction of incidence, it will deviate greatly from the direction of incidence and will be reflected in a different direction. That is, the light L is reflected approximately in the incident direction at the top 2a (between A and C) of the twisted bit p (between A and B) between each strand 2, and reflected in the incident direction at the remaining portion (between C and B). is scattered and reflected in a different direction. As a result, the cable l has a section (
A-B) becomes the "bright" part, and section (C-B) becomes the "dark" part.

In addition, in FIG. 3, for the sake of clarity, a case is described in which the direction of irradiation of the light L and the direction of reflection in the section (A-C) of the cable (2) are the same direction. Of course, the camera 3 and the light source 4 in FIG. It is set.

Therefore, the output voltage e of the camera 3 is maximum in the "bright" part of each strand 2 of the cable 1, and minimum in the "dark" part, as shown in FIG. 4(a).

Thereby, the strands 2 can be distinguished one by one.

This output signal e is waveform-shaped to obtain a continuous pulse signal P as shown in the figure (bl).The period of this pulse signal P indicates the twisting pitch p of the cable l, and the pulse width (A- C) is the "bright" part, low level width (C-B)
``Equivalent to Dark J-bu.''

Therefore, by adding the bit numbers of the "bright" part and the "dark" part, it is possible to detect the thickness of one strand.

For example, the effective field of view of the video camera 3 is 200 mm, and the number of bits (number of elements) of the image sensor is 2048 bits.
Then, the resolution is 200 mm + 2048 bits
=0.097mm/bit, and ■0.097mm/bit. It becomes 097 mm.

Here, if we take into account variations in the camera's own bits, vibrations of the workpiece (i.e., cable l), etc., the resolution is 0.5.
It is approximately mm/bit.

FIG. 5 shows a cable manufacturing apparatus to which the present invention is applied,
The manufacturing device 10 includes a wire twisting machine 1.1, a twisting port l2 for twisting a plurality of strands 2 pulled out from the wire twisting machine 11,
It consists of a cab stan l3 that pulls out the twisted cable l from the twisting port I2, a winder 14 that winds up the cable l pulled out from the capstan l3, and the like.

The stranding machine 1l is rotationally driven by a stranding machine motor l5, and the capstan l3 is rotationally driven by a transmission motor 16 via a transmission 17. Further, the winding machine l4 is rotationally driven by a winding motor 18. The rotational speeds of these wire twisting machine 11, capstan l3, and winding machine l4 can be adjusted individually and continuously by controlling the rotational speeds of motors l5, l6, and l8, respectively. It looks like this.

In addition, a generator for detecting the rotational speed is directly connected to the rotating shaft of the twisting machine 11, and the generated voltage of the generator is converted into the rotational speed and twisted to the speedometer (none of which is shown). Line machine 1
The rotation speed of 1 is displayed.

Cameras (video cameras) 20, 2l are arranged directly above the cable 1 at predetermined positions immediately after the twisting port l2 of the wire twisting machine l1 and immediately before the winding machine 1. Light sources 22 and 23 (positions corresponding to the light sources 4 in FIG. 2) are arranged diagonally below the cameras 20 and 2l, as shown by two-dot chain lines. The light sources 22 and 23 are connected to the cable l.
Immediately after the twisting port l2 and just before the winding machine 4, light is irradiated diagonally from above, and each camera 20, 2l receives the reflected light from the top 2a of each strand 2 of the cable l at the relevant position. It is designed to photograph the twist pitch.

That is, the camera 20 photographs the twisting pitch immediately after the twisting port l2 of the cable l, and the camera 2l photographs the twisting pitch immediately before the winding machine l4. These cameras 20, 2l
In order to improve the measurement accuracy, multiple (e.g., 8) pieces of wire diameter of cable l are photographed only at the center of the camera angle, and the total number of wires of cable l (e.g., 24 pieces) is calculated using a calculator described later. The twist pitch of the cable 1 is calculated by converting it into .

Output signals from these cameras 20 and 21 are input to a computing unit 25. This computing unit 25 calculates the twisting pitch Al of the cable l immediately after the twisting end l2 and the twisting pitch B1 immediately before the winding machine l4 based on signals manually input from the cameras 20 and 21.
is calculated, and a control signal is output to the stranding machine motor controller 27, the transmission motor controller 28, and the winding motor controller 29 so that the difference (A+B+) is zero.

These controllers 27 to 29 control the rotational speeds of the stranding machine motor 15, the transmission motor 16, and the winding motor 18, respectively, in response to control signals from the computing unit 25. Also, recorder 2
6 continuously records each twisting pitch A+, B+ immediately after the twisting port 12 of the cable 1 and immediately before the winding machine 14.

The operation will be explained below with reference to the flowchart shown in FIG.

Stranding machine motor 15, transmission motor l of twisted wire manufacturing equipment IO
6 and winding machine motor l8 are rotated at a predetermined rotational speed to rotate the twisting machine It, cab stun I3 and winding machine I4 in the direction of the arrow, and twist the strands 2 through the twisting port 12 to form the cable l. None, wind up on winder l4. The light sources 22 and 23 are
Light is irradiated to a predetermined position immediately before the twisting end 12 of the cable l and in front of the winder 14 (step l), and the surface of the cable l is imaged by the cameras 20 and 2l (step 2).

These cameras 20 and 21 collect the waveform data of the bright and dark parts of the reflected light on the surface of the cable l (Fig. 4(b)) (step 3), and calculate the l frequency of the waveform (the thickness of a single strand). (step 4).

Based on the signals input from the cameras 20 and 2l, the calculator 25 adds up the thickness of each strand 2 of the strands (n=8) that can be photographed at once by these cameras 20 and 2l with high accuracy. Then, the bits a1 and b1 for n pieces (eight pieces) of the cable 1 immediately after the twisting port 12 and immediately before the winder l4 are calculated (step 5). Further, the reference number m (=24 cables) corresponding to the twisting pitch of the cable l is input to the calculator 25 (step 6). The arithmetic unit 25 calculates this reference number m (=
24) by the number of captured images n (=8) (m/n) (step 7) to calculate the coefficient α (=3).

Next, the arithmetic unit 25 calculates the pitch of n number×(reference number/
n number), that is, a1×α and b+×α (step 8), each twisting pitch of the cable 1 with 24 strands is calculated immediately after the twisting port 12 and immediately before the winder 14. A+
(=a+xα) and B+ (=b+Xα) are calculated (step 9). The recorder 26 continuously records each twist pitch A+, Bt of the cable l based on the twist pitch signal output from the calculator 25 (step 10).

The computing unit 25 calculates the difference (A
+Bt) is calculated (step 1l) to determine its magnitude. If the difference is zero (AIBI=O) (step 12), the twist pitches A+ and B+ immediately after the twister l2 and immediately before the winder l4 are equal, and therefore the status quo is maintained, that is, the twister The rotational speeds of the Ik capstan 13 and the winder 14 are maintained at the current state (step 13).

As a result, the twisting pitch of the cable 1 becomes constant (step 14).

The twist pitch A1 is larger than the twist pitch B1 (At
-B+>0) (step 15) means that the twist immediately after the twisting port l2 is less than the twist immediately before the winder l4. Therefore, it is necessary to increase the rotational speed of the wire twisting machine 11 and to slow down the rotational speed of the capstan l3 and the winder l4. The computing unit 25 is the stranding machine motor controller 2
A control signal is output to the wire twisting machine 7 (step l6) to increase the rotational speed of the wire twisting machine motor l5 (step l7), and the rotational speed of the wire twisting machine 11 is increased (step 18).

At the same time, the computing unit 25 outputs a control signal to the transmission motor controller 28 (step 19) to lower the rotational speed of the transmission motor l6 (step 20) and lower the rotational speed of the capstan l3 (step 21). do. Furthermore, the computing unit 25
outputs a control signal to the winder motor controller 29 (step 22), lowers the rotational speed of the winder 18 (step 23), and lowers the rotational speed of the winder 14 (step 24). As a result, the twisting pitch A1 immediately after the twisting port 12
becomes smaller, and as a result, the twisting pitch A immediately after the twisting port l2 is equal to the twisting pitch B1 immediately before the winding machine l4.
(A+B+=0), and the twisting pitch of the cable l becomes constant (step 14).

Also, contrary to the above, twist pitch A+ is twist pitch B
If it is smaller than 1 (A+B+<0) (Step 2
5) means that the twist of the cable l immediately after the twist opening l2 is greater than the twist immediately before the winder l4. Therefore,
While lowering the rotation speed of the stranding machine l1, the capstan 1
It is necessary to increase the rotational speed of winder 3 and winder l4. The computing unit 25 outputs a control signal to the stranding machine motor controller 27 (step 26) to lower the rotational speed of the stranding machine motor 15 (step 27), and lowers the rotational speed of the stranding machine 11 (step 27). 28) Do.

At the same time, the computing unit 25 outputs a control signal to the transmission motor controller 28 (step 29), increases the rotational speed of the transmission motor 16 (step 30), and increases the rotational speed of the capstan 13 (step 31). do. Furthermore, arithmetic unit 2
5 outputs a control signal to the winding machine motor controller 29 (step 32), increases the rotational speed of the winding motor l8 (step 33), and increases the rotational speed of the winding machine l4 (step 34). . As a result, the twisting pitch A, immediately after the twisting port l2 becomes larger, and as a result, the twisting pitch A+ immediately after the twisting port l2 becomes equal to the twisting pitch B, immediately before the winding machine l4.
(AI Bl =O'), and the twisting pitch of the cable l becomes constant (step 14).

In this way, the twisting pitch of the cable l can always be maintained constant. In addition, the fluctuation of the twist pitch can be measured using the recorder 2.
6, the twist pitch of the cable I can be continuously recorded.

Moreover, since the cable l is imaged at the center of the cameras 20 and 21, the twist pitch can be measured with high accuracy without being affected by the quality of the images at both ends of the camera angle. By measuring each twisting pitch at two points immediately before the winding machine 14, it is possible to accurately grasp the fluctuations in the twisting pitch, and the twisting machine 11, capstan 1
3. It becomes possible to quickly follow each rotational speed of the winder l4 online.

(Effects of the Invention) As explained above, according to the present invention, a plurality of wires are twisted together to irradiate a certain electric wire/cable with light, and the light reflected from the cable is imaged by a camera. The wire diameter of each strand of the cable is read and the twist pitch is measured based on the read diameter of each strand, so the twist pitch of electric wires and cables can be measured online and continuously without contact. This makes it possible to significantly improve work efficiency. Furthermore, it becomes possible to accurately grasp fluctuations in the twisting pitch, and to adjust the operating speed of the wire/cable manufacturing equipment in response to fluctuations in the twisting pitch. This makes it possible to quickly follow-up control4 on-line, and has excellent effects such as significantly improving the quality of electric wires, cables, etc.

[Brief explanation of the drawing]

Figure 1 is a block diagram showing the principle of measuring the twist pitch of electric wires and cables according to the present invention, Figure 2 is a diagram showing the positional relationship between the cable, camera, and light source in Figure 1, and Figure 3 is An explanatory diagram showing the relationship between the light irradiated onto the cable and the reflected light. Fig. 4 is a diagram showing an example of the camera output signal based on the reflected light of Fig. 3. Fig. 5 is a cable to which the method of the present invention is applied. FIG. 6 is a flowchart showing a control procedure of the manufacturing device shown in FIG. 5. l... Cable, 2... Element wire, 3, 20, 21.
...Camera, 4, 22, 23...Light source, 10...Cable manufacturing device, 11...Twisting machine, I2...Twisting opening,
l3... Capsun, l4... Winder, l5, l
6, 18...Motor, 17...Transmission, 25...
Arithmetic unit, 26...Recorder, 27-29...Controller.

Claims (1)

[Claims] Light is irradiated onto an electric wire/cable formed by twisting multiple strands of wire together, and the light reflected from the cable is captured by a camera to read the wire diameter of each strand of the cable.
A method for measuring the twist pitch of electric wires and cables, which is characterized in that the twist pitch is measured based on the diameter of each of these read strands.