JPH0511561B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a cable bump detection device, more specifically, a cable bump detection device for detecting external abnormalities such as bumps that occur during the cable manufacturing process. Regarding.

[Prior Art] Various types of cable detection devices as described below are conventionally known. However, each has its own problems and is not put into practical use.

The first one utilizes an outer diameter detection device. In this case, upper and lower limits of the outer diameter of the cable are determined, and anything outside of these limits is considered abnormal. However, with this method it is not possible to detect small bumps that fall within the upper or lower limits of the cable outer diameter.

The second one is a commercially available contact roller type detector, as shown in FIG. That is, rollers 2a and 2b are arranged to sandwich the cable 1 from above and below, and the displacement of the axis of the roller 2a is converted into an electric signal by a displacement-electrical signal converter 3, and further by an amplifier 4.
The signal is amplified by the meter 5 and read by the meter 5. When this is used for hump detection, the electrical signal is subjected to differential processing. However, the change in the electrical signal is greatly affected by the feed speed of the cable 1, and when it is actually used, it is impossible to detect subtle bumps, making it impractical.

The third type is a commercially available non-contact two-point comparison outer diameter variation detector, which cannot be used with cables with large outer diameters due to the light receiving element.
Furthermore, if water droplets or the like adhere to the cable surface, false detection may occur.

The fourth is an optical detection device that detects uneven light reflection on the surface of a cable when there are bumps in it. However, this device is not actually used because its sensitivity varies greatly depending on how the light is applied, or because there are many false positives.

[Problems to be Solved by the Invention] An object of the present invention is to eliminate the above-mentioned conventional drawbacks and to detect humps in a cable having a large outer diameter with high precision.

[Means and effects for solving the problems] In order to solve the above problems, the present invention arranges two rollers in the longitudinal direction of the cable, and on the other hand,
A gap sensor is attached to a rod movable only in the vertical direction of the cable, and is configured to detect changes in the angle between the frame to which the two rollers are attached and the rod.

Here, the principle of this invention will be explained based on FIGS. 7A and 7B.

As shown in FIG. 7A, a frame 43 is attached to the lower end of the linear guide rod 42, which is movable only in the vertical direction, and is swingable in the plane of the paper about the lower end. Rollers 44a and 44b are attached to the lower surface of the left and right ends of the frame 43 and are rotatable on shafts perpendicular to the plane of the paper.

The rollers 44a and 44b are arranged so as to contact the surface of the cable 41 where the bump 41a is located. Here, as shown in the figure, one roller 44a contacts the top of the hump 41a,
When the other roller 44b is in contact with the reference surface of the cable, the angle that the frame 43 makes with respect to a line perpendicular to the rod 42 is θ, and
The height of 1a is a, and the distance between the centers of rollers 44a and 44b is b.

At this time, the following formula (1) holds true, and if θ is sufficiently small, formula (2) holds true.

tanθ=a/b...(1) θ≒a/b...(2) On the other hand, as shown in FIG. 7B, a gap sensor 45 is installed approximately at the center of the rod 42 at a distance of l from the rod 42. The distance when the rod 42 and the frame 43 are perpendicular to each other when the frame 43 is inclined at an angle of θ is defined as g ₀ .

At this time, the following formula (3) holds true, and if θ is sufficiently small, formula (4) holds true.

lsinθ=g−g ₀ =Δg ...(3) sinθ≒θ ...(4) From equations (3) and (4) Δg=l・θ ...(5) As is clear from equation (5), The change in the gap g (ie, Δg) and the relative angle θ between the frame 43 and the rod 42 are approximately proportional to each other, and the change in θ can be detected by detecting the change in the gap g.

Here, the following equation (6) holds true from equations (2) and (5).

Δg=l/b・a...(6) As is clear from this equation (6), increasing l,
If b is made small, Δg can be made as large as desired in principle even if the bump height a is small.

Further, since Δg is converted into a voltage V by a signal converter, the following equation (7) exists, and a signal change ΔV proportional to the height a of the hump can be obtained. The present invention uses such a principle.

ΔV=C·l/b·a (7) [Example] First, the configuration of the cable bump detection device 20 based on the above principle will be explained based on the side view of FIG. As shown in the figure, shafts 13a and 13b are inserted into the left and right lower ends of the frame 11, which has an inverted concave cross-sectional shape and is open at the bottom.
Rollers 12a and 12b made of metal, hard plastic, or the like are rotatably attached to the shafts 13a and 13b, respectively, via bearings. At the center of the lower end of the frame 11 is a support shaft 1.
4 is inserted through the support shaft 14, and the lower end of a sensor mounting rod 15 is rotatably attached to this support shaft 14. The upper end of this rod 15 extends in the left and right directions, and a gap sensor 16 is fixed to the center of the arm extending to the right.
This gap sensor 16 is designed to detect the gap g between the upper surface of the frame 11 and the upper surface of the frame 11. A cable 16a extends from the upper end of the gap sensor 16, and its tip is connected to a recorder (not shown). A tension coil spring 1 is attached to the tip of each of the arms extending to the left and right.
One end of each of 7a and 17b is locked, and the other end is connected to the left and right ends of the frame 11.

The tip of a cylindrical leg 18a of a linear guide 18 is attached to the center of the upper surface of the rod 15, and an extensible coil spring 19 is inserted into the leg 18a. The rollers 12a, 12b are pressed against the surface of the cable 1. That is, the rod 15 moves only in the direction perpendicular to the cable 1 (indicated by arrow A), so that changes in the angle of the frame 11 with respect to the rod 15 can be clearly discerned.

With this configuration, cable 1
If there are irregularities on the roller 12a or 1
Since the frame 2b moves upward, the frame 11 also moves upward, and the size of the gap g changes.This change is recorded by the recorder, and the acceptability of the cable can be determined based on the result.

The sensitivity of the gap sensor 16 can be adjusted by adjusting the distance l between the center of the gap sensor 16 and the center of the leg 18a of the linear guide 18. That is, if the distance l is made smaller, the sensitivity will be improved, and if it is made larger, the sensitivity will be reduced.

FIG. 4 shows an example of measurement using the hump detection device described above.

[Measurement conditions] Cable: External diameter φ27, CV (steam) Cable feed speed: 1.8 m/min Kump: Vinyl tape approximately 0.2 mm thick and 10 mm wide Under the above measurement conditions, Figure 3 shows When the cable 1 was pushed upward by the fixed roller 9 shown by the two-dot chain line and recorded with a recorder, the amplitude was detected by a pseudo bump with a height of about 0.2 mm attached with vinyl tape.
I was able to get a gap sensor output of 1.6V.

Furthermore, the fact that the output of the gap sensor fluctuates when there is no adhesive tape is probably due to the warping of the cable.

Next, an embodiment of the present invention will be described based on FIGS. 1, 2, and 5. In the above-mentioned example, the frame 11 is tilted due to the bending or deflection of the cable, and the output of the gap sensor changes. Therefore, it cannot be used in production lines where cable deflection occurs. This embodiment eliminates these drawbacks.

As shown in FIG. 1, the bump detection device 30 of this embodiment is constructed. That is, the frame 11, rollers 12a, 12b, spindle 14, gap sensor 16, etc. are arranged above the cable 1A, as in the example described above (see Fig. 3), and symmetrically therewith. Rollers 12aA and 12bA are disposed below the cable 1A so as to face the rollers 12a and 12b, respectively, and a frame 11A, a spindle 14A, a gap sensor 16A, etc. are also disposed. Lead wires extend from the gap sensors 16 and 16A, and their tips are connected to the non-inverting input terminal and the inverting input terminal of the differential amplifier 21, respectively.

With this configuration, when there are bumps on the top and bottom of the cable 1A, the gap sensor g ₁ due to the bottom bump will be negative compared to the standard, and the gap sensor g ₂ due to the top bump will be positive. Therefore, by taking the difference, a large output signal as shown by reference numeral 22 can be obtained.

Furthermore, as shown in FIG. 2, when the cable swings, the gaps _g3 and _g4 change to the same value, so the difference between them becomes "zero." That is, the influence of "runout" can be canceled, and it can be applied to manufacturing lines where runout occurs as described above.

When a hump was artificially provided and measured using the hump detection device 30, the results were as shown in FIG.

[Measurement conditions] Cable: External diameter φ38, 3-layer extruded CV (steam) Feeding speed: Undefined because the cable was moved back and forth between the rollers manually Knot: Approximately 0.2 mm thick and 19 mm wide Vinyl tape is attached From the measurement results As is clear, even bumps as high as 0.2 mm can be detected. In this embodiment, a comparator (not shown) is provided so that an alarm is issued when the signal swings above a certain level.

Additionally, although there is no restriction based on the thickness of the cable applied to this embodiment, in order to detect bumps all around the cable, three to four sets of bump detection devices should be arranged in the circumferential direction of the cable. is necessary.

[Effects of the Invention] According to the present invention, the detection accuracy of cable bumps does not depend on the outer diameter of the cable but only on the smoothness of the cable surface. , is effective for products where the line speed of the production line is slow.

[Brief explanation of drawings]

Figures 1 and 2 are a side view of a cable bump detection device according to an embodiment of the present invention, and a diagram showing a state in which the gap is canceled even if the cable swings. Side views showing the configuration, Figures 4 and 5 are Figures 3 and 1, respectively.
Figure 6 is a diagram showing the measurement results using the cable bump detection device shown in Figure 6. Figure 6 is a side view showing an outline of the conventional cable knob detection device, and Figures 7A and B are diagrams showing the principle of the present invention. It is a line diagram for explanation. 11, 11A...Frame, 12a, 12b,
12aA, 12bA...Roller, 16, 16A...
...Gap sensor, 19...Coil spring (elastic member).

Claims (1)

[Claims] 1 first and second rollers that are disposed in the longitudinal direction of the cable on a cable production line and rotate while in contact with the cable;
a frame that connects and supports the second roller; and a frame that is rotatably supported in the center of the frame around an axis that is parallel to and parallel to the rotation axes of the first and second rollers, and that extends in a direction perpendicular to the cable. A detection mechanism consisting of a rod that is movable by 100 mm, an elastic member that presses the rod in the direction of the cable, and a sensor that converts changes in the relative angle between the frame and the rod into electrical signals is installed on both sides of the cable. The sensors are arranged opposite to each other with respect to each rod, and the output signal from the sensor is inputted to the inverting/non-inverting input terminal of the differential amplifier. A cable bump detection device characterized in that the output of the cable is used as a bump detection signal.