JPS59123104A - Apparatus for continuously bridging electric cable - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a continuous electrical cable bridging device equipped with a device for high-frequency induction heating of cable conductors.

Conventionally, in equipment for continuously crosslinking electric cables, an uncrosslinked mixture is extruded and coated onto a cable conductor using an extruder head, and the mixture is run through a crosslinking pipe connected to the head, and steam or N2 gas filled in the crosslinking pipe is used. Crosslinked coated cables were manufactured by heating the uncrosslinked mixture from the outer periphery using a heating medium such as an inert gas such as In order to obtain a sufficiently cross-linked cable, it is necessary to sufficiently heat not only the outer layer of the sheath but also the innermost layer in contact with the central cable conductor, especially when the cable conductor has a large diameter. Because the conductor has a large heat capacity and the coating is thick, it takes an extremely long time to heat the innermost layer of the coating to the crosslinking temperature, and as a result, the heating section of the crosslinked pipe becomes extremely long, making it difficult to install a continuous crosslinking device. Not only did it take up a lot of space, but productivity was also poor.

Therefore, in order to quickly heat the innermost layer of the coating to the crosslinking temperature, the cable conductor fed to the extruder head was preheated, but this preheating was done using a solenoid coil with several turns. A diameter as close as possible to that of the conductor had to be used. However, with such induction coils, each time the cable conductor has a different diameter, it is necessary to replace it with an induction coil of the corresponding diameter, and this replacement work is extremely difficult because the induction coil surrounds the cable conductor. In particular, when a series of cable conductors having different diameters is connected, it is impossible to quickly replace the induction coil when the diameter of the running cable conductor changes. For this reason, it is necessary to match the diameter of the induction coil to the maximum diameter of the cable conductor.
For small-diameter cable conductors, heating efficiency is poor and energy loss is large.

In view of the above-mentioned points, the present invention configures the induction coil portion for high-frequency induction heating by movable straight conductor plates facing each other,
This provides a device that eliminates the need for the above-mentioned replacement work, and its configuration will be explained below with reference to illustrated embodiments.

FIG. 1 shows the main parts of the continuous crosslinking apparatus of the present invention. In the figure, 1 is an extruder head, 2 is a crosslinking pipe connected at one end to the head, and the extruder head 9 is connected to the extruder head. A heating section 3 is formed by filling and circulating a heating medium such as N2 gas in the tube, and a cooling section 4 is formed by filling and circulating cooling water in the rear half of the skeleton. Reference numeral 5 designates an enlarged portion for installing and storing a guide plate for high-frequency heating provided in the crosslinked pipe section immediately after the extruder head 1, reference numeral 6 an end seal, 7 a water surface of cooling water,
Reference numeral 8 denotes a high-frequency power source, 9 a connecting wire for connecting the high-frequency power source and the above-mentioned induction plate, and 10 the induction plate for high-frequency heating installed in the enlarged portion 5.

In such a continuous crosslinking device, the conductor of the cable is fed to the extruder head and coated with an uncrosslinked insulation mixture, and as it runs on the guide plate 10, it is heated by high frequency induction and runs through the heating section 3, During this time, the uncrosslinked coating is heated from the outer periphery by the heating medium, and the innermost layer is also heated by the cable conductor, which has become hot due to the induction heating, so that even the innermost layer is completely crosslinked. ,
After passing through the cooling section 4, the cable orI'i is sufficiently cooled and runs outside through the end seal 6. Then, the above-mentioned guide plate 10 is
It is adjusted to correspond to the cable diameter in a similar manner.

FIG. 2 shows an embodiment of the induction plate 1o for high-frequency induction heating, and in the same figure, 11 and 12 are shown.
13.14 is a connecting portion formed by bending one end of each straight conductive plate 11.12, and 15 is connected to the connecting portion 13.14 to connect the straight conductive plate 11. .12 is a flexible conductor short-circuiting, 16.17 is each of the straight conductor plates 11
．． Each terminal portion 1 is a terminal portion bent at the other end of 12.
6.17 are each provided with a flexible portion 18.19020
．． 21 is a connection wire connected to the flexible portion 18.19, and this connection wire 20.21 connects the straight conductor plate 11.1.
Connect 2 to a high frequency power source. Reference numeral 2+2 is an insulating adjustment rod for adjusting the distance between the bottom-shaped conductor plates 11 and 12, and this distance can be adjusted by cutting threads in opposite directions into the adjustment rod 22 and adjusting each screw portion. If the straight conductor plates 11 and 12 are screwed together in length, by turning this adjustment lever both bottom conductor plates 11 and 12Fi can be moved toward or away from each other, so that the mutual spacing can be adjusted. Instead of using the screw rod as described above, the adjustment rod 22 is attached to the straight conductor plate 11, 12 at the end of each rod at the very center, and the rods are attached to the front and back. The distance between the straight conductor plates 11 and 12 may be adjusted by moving the straight conductor plates 11 and 12 toward and away from each other. Alternatively, it is also possible to adopt an appropriate means for adjusting the facing distance by mutually moving both bottom-shaped conductor plates 11, 12. The adjustment lever is operated by leading out of the enlarged portion 5 of the bridge pipe shown by the chain line.

The high frequency current flowing through the straight conductor plate 11 generates a magnetic flux φ, and the high frequency current flowing through the other straight conductor plate 12 generates a magnetic flux φ2.
The conductor of the cable C running between the two bottom-shaped conductor plates 11.12 is heated by high-frequency induction by the magnetic fluxes φ0 and φ2 between the two bottom-shaped conductor plates 11.12, and the opposing distance d between the two bottom-shaped conductor plates 11.12 is If the diameter of the table 0 is different, the opposing distance d is adjusted using the adjusting rod 22. Further, the length t of the straight conductor plate 11.12 is made long enough to sufficiently inductively heat the cable conductor so that even the innermost layer of the uncrosslinked coating is completely crosslinked.

By configuring the guide plate 10 as described above, even if the diameter of the cable differs, it is possible to immediately adjust the stationary conductor plates 11 and 12 to an appropriate facing distance d corresponding to the diameter. A good cable can be manufactured without a decrease in heating efficiency. According to experiments, the core conductor diameter is 1
When continuously bridging a cable consisting of a 8Tnm cable with a sheath diameter of 45 mm and a cable with a core conductor diameter of 29.0 BB and a sheath diameter of 70 mm, the length of the straight conductor plate 11.12 was determined. Guidance plate 10 with t of 8001BB and facing distance variable from 30mm to 50grR
is connected to a high frequency power source of 10KH2,150KW, the cable is run continuously, and the distance between the straight conductor plates 11 and 12 is adjusted by adjusting the distance between the straight conductor plates 11 and 12 from the distance of 60BB to the distance of 85gyH according to the diameter of each cable portion using the rod 22. When the heating efficiency was changed to 35% in each case, it was possible to obtain a cable that was completely crosslinked to the innermost layer of the coating.

The guide plate 10 of the embodiment shown in the second figure described above has straight conductor plates 11 and 12 short-circuited by a flexible conductor 15, but instead of providing such a flexible conductor 15, a structure as shown in the third figure is used. In the guide plate 10 of the embodiment shown in FIG. 3, 32 is a straight conductor plate, and 33 and 34 are each folded at the upper end of the straight conductor plate at right angles to the plane of the conductor plate. 35 and 36 are slide connecting plates bent at right angles to the surface of the conductor plate at the lower end of the conductor plate; 37 is a slide shorting plate; 38 and 39 are slide terminal plates;
Both are long holes for insertion of coupling bolts. A slide shorting plate 37 is connected to the slide connecting plates 33 and 34 at the upper end with bolts 1, a slide terminal plate 38 is connected to the slide connecting plate 35 at the lower end, and a slide terminal plate 39 is connected to the slide connecting plate 36 with bolts. Combine with . These bolts are inserted into the respective elongated holes 40 to connect them, but by loosening the bolts and nuts and adjusting the mutual positions of the plates, the straight conductor plates 31 and 32 can be moved oppositely. Opposing distance d
can be adjusted arbitrarily.

Note that the length 2 of the straight conductor plates 31 and 32 is formed to a sufficient length as in the one shown in the second figure, and the installation in the bridge pipe is done using an appropriate insulating support member. and 39 are connected to a high frequency power source through appropriate connection lines or the like. In this embodiment as well, the straight conductor plates 31 and 32 facing each other in parallel are similar to the embodiment shown in the second drawing.
The cable conductor is heated by induction by high-frequency magnetic flux generated between both conductor plates by running a cable between the two conductor plates.
Adjust.

In addition, in the embodiment shown in the first figure, the guide plate ratio is installed in the bridge pipe at the rear stage of the extruder head 1, but it is installed at the front stage of the extruder head 1, and the cable conductor W is placed between the stationary conductor plates. The cable conductor may be heated by high frequency induction by running it, or the guide plate 10 may be installed before and after the extruder head 1, and the end of the crosslinked pipe may not be connected to the extruder head. If you are far away,
A guide plate 10 can be installed between the end of the bridge tube and the extruder head. The above-mentioned cross-linked pipe is not limited to the vertical type as shown in the first figure, but may also be of any type, such as an inverted U-shape or a horizontal type.

As described above, according to the present invention, an induction plate having straight conductor plates that face each other in parallel and whose facing interval is variable is used for high-frequency induction heating of the cable conductor 8. Even if the distance between the straight conductor plates differs, there is no need to replace the induction coil as in the conventional method, and the distance between the opposing straight conductor plates can be immediately adjusted to the appropriate distance according to changes in the cable diameter. Therefore, heating efficiency is good and productivity can be significantly improved.

[Brief explanation of the drawing]

FIG. 1 is a drawing showing an embodiment of the electrical cable continuous bridging device of the present invention, and FIGS. 2 and 3 are perspective views each showing an embodiment of a guide plate. 1: Extruder head 10: Guide plate 11.12.
31.32; Straight conductor plates 15.33, 34.37: Short circuit portions 16 to 19.35.36.38.39; Terminal portion Patent applicant Furukawa Electric Co., Ltd. Agent
Patent attorney Oka 1) Kikuji (and 1 other person)

Claims (1)

[Claims] A high-frequency heating induction device in which the terminals at one end of each of the opposing parallel straight conductor plates are connected to a high-frequency power source and the other ends are short-circuited, and the straight conductor plates are movable relative to each other so that the spacing between them can be varied. A continuous electrical cable bridging device characterized in that a plate is installed at one or both of the front stage and the rear stage of an extruder head, and the conductor of the cable running between each of the straight conductor plates is heated by high frequency induction.