JPH0532844B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a device for eliminating rotation due to untwisting of cables in a continuous vulcanizer mainly used for manufacturing power cables.

[Conventional technology and its problems]

Catenary-type, inclined-type, horizontal-type, and vertical-type vulcanizers are known as continuous vulcanizers for power cables, but in the former three vulcanizers, the thickness of the rubber or plastic insulation layer relative to the conductor diameter is It is difficult to manufacture cables with large ratios. During crosslinking in the vulcanized tube, the eccentricity of the insulating layer increases due to the influence of gravity, making it impossible to make a good cable.

As a countermeasure for this, in the die section of the crosshead at the entrance of the vulcanized tube, the extrusion thickness of the insulating layer is made thicker in advance on the side where the thickness decreases due to sagging than on the side where the thickness is increased by an amount equivalent to the eccentric amount. Although it is possible to eliminate uneven thickness by offsetting the amount of eccentricity caused by the sagging phenomenon, it is by no means easy to implement this method. This is because, if the side where the thickness decreases due to gravity is defined as point a, and the side where the thickness increases is defined as point b, it is necessary to know points a and b at the crosshead section.

However, the vulcanized tube is a pressure vessel and cannot be opened during operation due to internal pressure. Follow,
Points a and b at the crosshead section must be determined from the positions of points a and b at the end seal outlet by measuring eccentricity at the end seal outlet of the vulcanized tube, which is the only measurable location. , it is very difficult to make this positional correspondence. The reason for this is that the cable rotates under the influence of twisting during cross-linking.

That is, conductors for power cables are generally made by twisting together a plurality of thin single wires. For example, a single wire is twisted in many layers, with one wire in the center, six wires around the periphery, and 12 wires on top. When tension is applied to such conductors, they twist in the untwisted direction.
On the other hand, taking a catenary continuous vulcanizer (CCV) as an example, the tension applied to the cable is the catenary constant multiplied by the unit weight of the cable.
This creates considerable tension. This tension causes the cable to rotate on its own axis in an attempt to untwist between the metering capstan located in front of the crosshead and the tensioning capstan located behind the end seal. Furthermore, the number of rotations varies depending on the structure of the conductor and the length of the vulcanized tube. Therefore, even if the points a and b and the amount of eccentricity are checked at the end seal outlet, it is not possible to determine where points a and b are at the crosshead, and there is no way to adjust the eccentricity.

One method is to scratch the die of the crosshead, use the scratches to make lines on the cable surface, and use these lines as a reference to correlate the positions. Since the position is affected by sagging due to gravity, the exact number of rotations cannot be determined, and therefore this method cannot necessarily be said to be successful. Furthermore, it is also undesirable to damage the surface of the cable as a product.

The inventors believed that if the cable could be manufactured without rotating it, it would be easier to correlate the positions of points a and b at the end seal outlet and the crosshead.
Focusing on the fact that there is no need to damage the cable surface, we have developed the device of the present invention that can eliminate the rotation of the cable in the cross-linked pipe.

[Means for solving problems]

The cable frequency prevention device of the present invention, which solves the above-mentioned problems, consists of a pair of rollers, a pair of endless belts including a track pillar, or a combination thereof, which grips the cable so that it can run at the end seal outlet of the vulcanized tube. a frame that is rotatably fixed around a path line of the cable and rotatably supports a roller group of the gripping means or a support roller of an endless belt; and a cable gripped by the gripping means. It is also equipped with a drive motor that rotates the cable in a direction opposite to the direction of rotation due to the untwisting force of the cable, the same number of rotations as the rotation speed.

[Effect]

When the cable during crosslinking is reversed the same number of times as the number of rotations due to untwisting, the actual number of rotations of the cable becomes zero, and the positions a and b at the crosshead correspond to the positions at the end seal outlet. Generally, point a at the crosshead is on the upper side of the cable and point b is on the lower side of the cable, and the same is true at the end seal outlet. Therefore, if the position of the die is adjusted based on the amount of sagging at the end seal exit section, so that the extrusion thickness on the side of point a at the crosshead section becomes thicker by the amount of sagging, the end seal has already stopped sagging. The eccentricity of the insulating layer at the seal portion is naturally corrected to zero during crosslinking.

Therefore, according to the present invention, it is possible to manufacture a high-quality, thick-walled insulated cable even in a crosslinking device that is affected by gravity.

〔Example〕

The accompanying drawings show embodiments of the invention.

FIG. 2 shows the anti-rotation device 10 of the present invention.
The location of the device 10 when adopted in a CCV is shown. In the figure, 1 is a cable, 2 is a metering capstan for feeding out a conductor, 3 is an insulating material extruder, 4 is a vulcanized tube, 5 is its end seal, and 6 is a tensioning capstan. The device 10 is installed at the outlet of the end seal 5 as shown.

FIG. 1 shows a specific example of the anti-rotation device 10. As shown in FIG.
As shown in the figure, a plurality of V rollers 11 are arranged parallel to the line L on both sides of the cable pass line L. A group of rollers lined up on one side of the pass line is rotatably supported by a movable frame 12 with its spindle oriented perpendicular to the line L, and a group of rollers on the other side is similarly supported by a movable frame 13. The cable is passed between this pair of roller groups and held by the V-groove surface of each roller.

Reference numeral 14 denotes a gap adjustment mechanism between gripping surfaces provided as necessary to enable gripping of cables of different diameters. This adjustment mechanism consists of frames 12,1
3, a plurality of pairs (two pairs in the figure) of links 14a are provided at different positions in the longitudinal direction of the pass line; a screw shaft 14b parallel to the pass line L; A worm gear consisting of a block 14c which is screwed into the threaded portion of the frame and hinge-connected one end of the pair of links 14a, a worm gear 14d fixed to the screw shaft and a worm 14e meshed with the worm wheel 14d, and an eye bracket of the frames 12 and 13. It consists of a guide rod 14f passed through and a handle or a motor (not shown) connected to the worm, and rotates the worm 14e to rotate the frame 1.
2 and 13, the paired roller groups are moved in parallel in directions toward and away from each other, but the structure is not particularly limited to this.

15 is a cylindrical frame that supports the screw shaft 14b and the guide rod 14f. This cylindrical frame is arranged concentrically on the pass line L, and the fixing member 1
It has a cylindrical support shaft 17 supported by 6, and can rotate together with the support shaft around a pass line.

18 is two large and small sprocket wheels 18
It is a power transmission mechanism to a support shaft 17 consisting of an endless chain 18c extending between wheels a and 18b, and a shaft 18d to which a small sprocket wheel 18b is attached is connected to a drive motor 20 with a transmission via a clutch 19. is connected to. 21 is a switching lever for the clutch 19.

In the illustrated device 10 constructed as described above, the cylindrical frame 15 is rotated together with a group of rollers in a direction opposite to the rotational direction of the cable by the power from the motor 20, and the rotational force is transmitted from the group of rollers to the cable. .

Note that the rotation speed of the cylindrical frame 15 is controlled to be the same as the rotation speed of the cable. The following two control methods can be considered at this time. Part 1
First, if the clutch 19 of the device 10 is set to neutral and the number of rotations of the support shaft 17 or shaft 18d is detected by a sensor (not shown), the number of rotations x during the cable's journey from the crosshead to the end seal can be determined; The degree of self-transfer v can also be determined from the length of the bridge pipe and the running speed of the cable, so after this, the clutch 19 is engaged and the frame 15 is first
Rotate x times in the opposite direction to the rotation direction, and then,
The frame 15 is rotated in a direction opposite to the rotation direction at the same speed as the previously determined speed v, and crosslinking is performed while correcting the amount of rotation. Next, when the cross-linked cable leaves the end seal in this state, the thickness deviation of the insulating layer is measured, and the die position of the crosshead is finally adjusted in a direction that eliminates the eccentricity. From then on, the method is to continue crosslinking while correcting the rotation by rotating the frame 15 at a speed of v.

Another method is to provide a rotation detection device other than the device 10 (this device may also be based on the device 10 of the present application) between the device 10 and the end seal 5. This method performs almost the same control as the former method based on the number of rotations x and the degree of self-transfer v detected by the vehicle. In this latter method, the value of v, which may change during crosslinking, is constantly determined and the rotation can be accurately corrected based on that value, so there is no accumulation of correction errors, and the initial rotation speed can be used as the subsequent rotation speed. This method is more reliable than the former method. In any case, such control is only possible with the anti-rotation device of the present invention.

The cable gripping means may include a pair of endless belts such as a caterpillar or rubber belt with V grooves, arcuate grooves, etc. wrapped around the head and tail rollers and arranged in parallel, or one with a group of rollers,
The other may be an endless belt. In short, any device may be used as long as it can hold the cable in a state that allows it to run and transmit the rotational force of the frame 15 to the cable.

〔effect〕

If you use the anti-rotation device of this invention described above,
Since rotation due to untwisting of the cable during cross-linking can be eliminated, a, b at the end seal exit part
From the position of the point, it is possible to accurately determine the position of points a and b in the crosshead section, and to reliably adjust the eccentricity of the extruded layer using the die. Alternatively, even with a horizontal continuous vulcanizer, it is possible to manufacture thick-walled cables without uneven thickness, which has been difficult in the past.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of the anti-rotation device of the present invention with the cylindrical frame cut away;
FIG. 3 is a diagram showing locations of arrangement with respect to CCV. 10... Anti-rotation device, 11... V roller, 1
2, 13... Movable frame, 14... Space adjustment mechanism, 15... Cylindrical frame, 16... Fixed member,
17... Support shaft, 18... Power transmission mechanism, 19...
Clutch, 20... Drive motor, L... Cable pass line.

Claims (1)

[Claims] 1. Consisting of a pair of roller groups or a pair of endless belts including a caterpillar, or a combination thereof, for gripping the cable so as to run at the end seal outlet of a catenary, inclined or horizontal vulcanizing tube. a cable gripping means; a frame rotatably positioned around a path line of the cable to rotatably support a roller group of the gripping means or a support roller of an endless belt; and the frame together with the cable gripped by the gripping means. A cable rotation prevention device for a continuous vulcanizer, comprising a drive motor that rotates the cable by the same number of rotations as the rotation speed in a direction opposite to the rotation direction due to the untwisting force of the cable. 2. The cable rotation prevention device for a continuous vulcanizer as set forth in claim 1, wherein the cable gripping means includes a gap adjustment mechanism between gripping surfaces.