JPS59123103A - Device for continuously crosslinking rubber and plastic insulated 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 crosslinking device equipped with a device for high-frequency induction heating of conductors of rubber or plastic insulated cables.

Conventionally, in equipment that continuously crosslinks rubber and plastic insulated cables, rubber mixed with a crosslinking agent is used.

An uncrosslinked mixture such as plastic is extruded and coated onto a cable conductor using an extruder head, and is run through a continuous crosslinked pipe connected to the head. Crosslinked sheathed cables were manufactured by heating the crosslinked mixture coating from the outer periphery to crosslink it and then passing it through a cooling medium such as cooling water, but in order to obtain a cable in which the uncrosslinked mixture coating was sufficiently crosslinked, 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 is large in diameter, the heat capacity of the conductor is large and the sheathing is Since the coating is thick, it takes an extremely long time to heat such an uncrosslinked mixture coating from the outer periphery until the innermost layer of the coating reaches the crosslinking temperature.
As a result, the length of the heating section of the crosslinked pipe through which the uncrosslinked mixture coated cable runs becomes extremely long, which not only increases the installation space of the continuous crosslinking device but also results in poor productivity. Therefore, in order to quickly heat the innermost layer of the uncrosslinked mixture coating to the crosslinking temperature, the cable conductor that is fed to the extruder head is preheated, and the uncrosslinked mixture is extruded and coated onto it to inject it into the crosslinked pipe. Previously, the cable conductor was heated and cross-linked by running it, but high-frequency induction heating was performed using a solenoid-type fill with several turns to preheat the cable conductor. The diameter had to be as close as possible to the diameter of the cable conductor passing through it.

In such a conventional high-frequency induction heating coil, as shown in the first diagram, a cooling water pipe is attached to the fill part a, and the diameter of this coil part a corresponds to a specific cable conductor diameter. Coils must be replaced for cable conductors with different diameters, but this replacement work is difficult to do, especially in the case of cables with continuous cable conductors of different diameters. Because the cable conductors run through the cable, it was impossible to prevent the heating efficiency from decreasing by replacing the coils for each conductor diameter. For this reason, it is necessary to match the diameter of the coil to the maximum diameter of the cable conductor, which has the drawback of extremely poor heating efficiency and increased energy loss for small diameter cable conductors.

In view of the above-mentioned points, the present invention provides a device in which the coil portion for high-frequency induction heating can be easily replaced according to the diameter of the cable. do.

Figure 2 shows an induction plate for high-frequency induction heating of a cable conductor according to the present invention.In this case, instead of generating magnetic flux by an induction fill as in the conventional case, it is induced by parallel straight conductor plates facing each other. It generates magnetic flux for heating. In the same figure, the first and second straight conductor plates are arranged parallel to each other, each end of which is bent to form a terminal portion 3.4, and each terminal portion 3.4 is connected to a high-frequency power source. A bolt insertion hole 5.6 is provided for connecting the conductor from the straight conductor plate 1.2, and the other end of each straight conductor plate 1.2 is a bent portion. , 8 and the connecting portion 9 are integrally connected and short-circuited. A series of consecutive terminals as described above! A cooling water steel pipe 10 is attached to the outer surface of the 3% straight conductor plate 1, the bent portion 7, the connecting portion 9, the bent portion 8, the straight conductor plate 2, and the terminal portion 4.

When the terminal portion 3.4 is connected to a high-frequency power source, a high-frequency electric current flowing in the longitudinal direction of the straight conductor plate 1, magnetic flux φ due to 3-, and a high-frequency electric current flowing in the longitudinal direction of the straight conductor plate 2, A magnetic flux φ2 is generated over the entire length between the perpendicular conductor plates 1.2. Therefore, if the cable C is run between the perpendicular conductor plates 1.2, the conductor of the cable will pass through the high frequency magnetic fluxes φ0 and φ2, and will be heated by induction. The facing distance d between the straight conductor plates 1.2 is such that a small gap is maintained between the inner surface of each straight conductor plate and the running cable C, and the distance is as close as possible to the cable diameter.

In addition, the length of the straight conductor plate should be long enough to sufficiently inductively heat the cable conductor so that the uncrosslinked mixture coating is completely crosslinked to the innermost layer. ◇In the same figure, 11 is a high frequency power source, and a straight conductor plate 1.
The straight conductor plate 1.2 is installed in the cable conductor running path between the metering capstan 12 and the extruder head 13, and the 014 is connected to the extruder head 13 model. It is a cross-linked pipe, and a heating medium such as heated and pressurized steam or an inert gas such as N2 gas is filled and circulated in the pipe near the c-shaped end of the bow to form a heating section 15.
A cooling section 16 is formed in the latter half by filling and circulating cooling water. The cable conductor 0 is fed from a feed reel, passes through a metering capstan 12, passes between the straight-plane conductor plates 1.2 of the guide plate, is extruded and coated with an uncrosslinked mixture in an extruder head 13, and is crosslinked. While traveling in the pipe 14, the uncrosslinked mixture coating is heated from the outer periphery by a heating medium in the heating fi 15 and crosslinked, and then cooled in the cooling section 16 before coming out of the crosslinked pipe. At this time, the cable conductor is heated by high-frequency induction between the straight conductor plates 1.2, so that it reaches a high temperature and passes through the extruder head 13 and runs through the heating section 15, so that the uncrosslinked mixture coating is heated. The innermost layer is also heated by the hot cable conductor, resulting in complete crosslinking throughout the entire thickness of the coating.

As described above, the cable conductor C is
is heated by high frequency induction, but the straight conductor plates 1.2 are used whose spacing 6 is set close to the diameter of cable conductor 0, so in the case of cable conductors with different diameters, the conductor Replace with a guide plate having a distance d corresponding to the diameter. This replacement is easy, even when the cable conductor is running, because the straight conductor plates 1.2 are just facing each other in parallel and do not surround the cable conductor like a conventional coil. The heating efficiency when performing high-frequency induction heating at l0KH2 using the above-mentioned induction plate is as follows: the distance d between the straight conductor plates 1.2 is 541,
When the length L is 8 G O 翳, when the diameter of the heated object is 22 g, it is 4L5%, and when the diameter is 15 m, it is 2 L.
04%, and 157% when the same diameter is 1O and 8gH. According to experiments, cable conductor thickness is 600- and 250-
- When the straight conductor plate 1.2 has a length of 800 mm, the length of the straight conductor plate 1.2 is 800 mm. The cable conductor running between the rectangular conductor plates 1 and 2 was heated to 130°C by connecting the plate to a high frequency power source of 10KH, 10KW, and the cable conductor running between the plane-perpendicular conductor plates 1 and 2 was heated to 130°C. - It was possible to produce a bridged cable.And when the part of the cable conductor with a thickness of 600- is running on the guide plate, the distance between the straight conductor plates 1.2 is 40 jn.
A straight conductor plate 1.m is set, and as soon as the cable conductor fed from the feeding wheel progresses and a 250mm thick conductor portion comes along, the straight conductor plate 1.m is set. 2 was replaced with a guide plate with a distance d of 30 am, and even though the cable conductor was running continuously without stopping during that time, the replacement work could be completed quickly.

In addition, in the above-mentioned embodiment, an example was shown in which the guide plate was installed in the front stage of the extruder head 13 shown in FIG. As shown, it can also be installed in a crosslinked pipe downstream of the extruder head 13, and in this case as well, it is possible to obtain a cable that is completely crosslinked up to the innermost coated layer.

When installing in a bridge pipe in this way, the straight conductor plate 1.
2 is supported by an insulating support, and the connection between the terminal portion 3.4 and the high frequency power source outside the bridge pipe is made using an insulating seal member 8 which penetrates the wall of the bridge pipe. Further, as described above, the guide plate may be installed not only at either the front stage or the rear stage of the extruder head 13, but also at both. In addition, when the end of the crosslinked pipe is not connected to the extruder head but is separated, the guide plate can be installed between the extruder head and the end of the crosslinked pipe, and the continuous crosslinking device is connected to the third It is not limited to the vertical type as shown in the 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, the high-frequency induction heating of the cable conductor is performed by using an induction method in which straight conductor plates 1.2 are opposed in parallel without using an induction coil surrounding the cable conductor as in the conventional method. Since a plate is used, it is possible to easily and quickly replace the cable conductor even while the cable conductor is running. In this way, conventional induction coils cannot be replaced without stopping the running operation and disassembling each time the cable conductor diameter differs; In contrast, the guide plate of the present invention can be easily attached/detached and replaced in any case, making it easier to manufacture cables. It will greatly improve your sexuality.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a conventional induction coil, FIG. 2 is a perspective view of an induction plate of the present invention, and FIG. 3 is a drawing showing a continuous crosslinking device of the present invention. 1.2: Straight conductor plate 3.4: Terminal part] 3: Extruder head 14: Cross-linked pipe patent applicant Furukawa Electric Co., Ltd. Representative Patent attorney Oka 1
) Kikuji (and 1 other person) Rod 3 Figure 12 Rod 1 Figure 2

Claims (1)

[Claims] A high-frequency heating induction plate, which is formed by connecting the terminal portion of one end of each opposing parallel straight conductor plate to a high-frequency power source and short-circuiting the other end, is installed on either the front stage or the rear stage of the extruder head, and on both sides of the extruder head. A continuous cross-linking device for rubber or plastic insulated cables, characterized in that the conductor of the cable running between the straight conductor plates is heated by high frequency induction.