JP4087016B2 - Lead sheath extruder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lead sheath extruder for an OF cable suitable for extrusion coating a lead sheath on a cable core.
[0002]
[Prior art]
The OF cable is provided by extruding a metal sheath such as a lead sheath on a cable core formed by winding an insulating paper on a conductor having an oil passage in the center and providing an insulating layer, and an anticorrosion layer on the outermost layer. The structure is provided. The insulating layer is impregnated and filled with insulating oil.
[0003]
By the way, there are a vacuum sheath method and a mass impregnation method as a manufacturing method of the OF cable. In the vacuum sheath method, in order to prevent bubbles and water harmful to electrical properties from adhering to the insulating paper constituting the insulating layer, a metal sheath is extruded on the cable core in a vacuum, and then insulating oil is applied from the end of the sheath. It is an impregnation method and is suitable for the production of a relatively short distance cable.
[0004]
In the mass impregnation method, in order to prevent bubbles and water harmful to electrical properties from adhering to the insulating paper constituting the insulating layer, the insulating layer of the cable core is impregnated with insulating oil in advance in a vacuum, and then the metal sheath is extrusion coated. This method is suitable for manufacturing a cable of a relatively long distance of several tens of kilometers. For this reason, it is still used for the production of long submarine OF cables.
[0005]
The mass impregnation method is a state in which the insulation oil is almost filled and sealed in the cable core insertion passage of the extruder so that air bubbles do not enter the insulation layer when the metal sheath is extrusion coated on the cable core impregnated with the insulation oil. Then, the metal sheath is extruded and coated while the cable core impregnated with the vacuum drying oil is immersed in the insulating oil in the cable core insertion passage. At this time, in order to prevent the insulation oil from deteriorating due to the heat of sheath extrusion, the lead sheath having a lower extrusion temperature than the aluminum sheath is used as a metal sheath for extrusion coating while the cable core is immersed in the insulation oil. Is suitable.
[0006]
[Problems to be solved by the invention]
As described above, in the mass impregnation method, when the lead sheath is subjected to extrusion coating while the cable core is immersed in the insulating oil, the insulating oil almost filled and sealed in the lead sheath extruder takes the heat of the extruder, and the time It gets hot as time goes by. When the insulating oil becomes high temperature, there is a possibility that the seal packing for preventing the leakage of the insulating oil and the insulating oil deteriorates early.
[0007]
Insulating oil filled in the extruder usually has an ignition point of 400 ° C. and a flash point of 140 ° C. The temperature of the extruder is controlled at 300 ° C., so the insulating oil in the extruder is 150 ° C. The temperature became as high as ˜200 ° C., and the temperature was higher than the flash point, and it was necessary to pay close attention to the occurrence of fire.
[0008]
[Means for Solving the Problems]
The present invention was made in view of the above circumstances, so that the temperature of the insulating oil supplied into the lead sheath extruder does not rise to a high temperature above the flash point, preventing early deterioration of the insulating oil and seal packing, An object of the present invention is to provide a lead sheath extruder that eliminates the risk of fire.
[0009]
In order to achieve the above object, according to the lead sheath extruder of the present invention, a die, a nipple and a nipple holder are arranged in the extrusion head, and a lead extrusion flow path is provided between the die and the nipple. Forming a cable core insertion passage through which a cable core that has already been impregnated with oil is inserted into the nipple holder, and inserting the cable core into the cable core insertion passage while being immersed in the insulating oil supplied in the cable core insertion passage. In a lead sheath extruder that guides into nipples and dies and extrudes lead from the lead extrusion flow path to extrude and coat the lead sheath on the outer periphery of the cable core, the insulation supplied into the cable core insertion passage oil forcibly circulated by those of Ru provided with an insulating oil circulation means for discharging to the outside of the insertion passage.
[0010]
Also, insulation oil circulation means are formed between the oil pipe disposed in the cable core insertion path, the cable core and the oil pipe to be inserted into the oil passage tube, is supplied to the cable core insertion path Is formed between the nipple holder and the oil passage pipe, and the insulating oil is supplied from the outlet side of the insulation oil forward passage to the oil passage pipe and the nipple. Insulating oil return flow path that circulates in the direction opposite to the insertion direction of the cable core via the oil communication passage between the insulating oil supply port and the insulating oil supply port provided on the inlet side of the insulating oil forward flow path. And an insulating oil discharge port provided on the outlet side of the oil return flow path.
[0011]
Further, as described in claim 2 and is characterized in that a cooler to lower the temperature of the insulating oil discharged from the discharge port of the insulating oil in the insulation oil recovery flow path.
[0012]
When the lead sheath extruder of the present invention is used, new insulating oil is supplied into the cable core insertion passage, and this is forced to flow and discharged out of the insertion passage. Even if the insulation oil is heated by the heat of the lead sheath extrusion coating on the cable core, it will not exceed the allowable limit and will not rise to a high temperature, thus eliminating the risk of premature deterioration of the insulation oil and seal packing. Can do.
[0013]
In addition, since the temperature of the insulating oil supplied into the cable core insertion passage of the extruder does not rise above the flash point, there is no need to worry about the occurrence of a fire, making OF cable manufacturing work safer. It can be carried out.
[0014]
Further, by using the insulation oil circulation means, a cable core insertion path, it is possible to smoothly flow the insulating oil, preferably can be prevented more efficiently the insulating oil becomes hot.
[0015]
Furthermore, if the thing of the structure described in Claim 2 is used, it will cool when discharging | emitting the insulation oil which temperature rose in the process which distribute | circulates the inside of a cable core insertion path out of a cable core insertion path, The temperature of the insulating oil discharged to the outside of the insertion path can be lowered more reliably, and the risk of fire occurrence can be avoided more effectively.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows the main configuration of a mass impregnating OF cable manufacturing apparatus, a cable core A vacuum drying oil impregnation apparatus 10 in which an insulating paper is wound on a conductor and an insulating layer is provided on the conductor, A lead-sheath extruder 20 according to the present invention is provided that extrudes and coats a lead sheath C on a cable core A in which an insulating layer is oil-impregnated.
[0017]
The vacuum drying oil impregnation apparatus 10 includes a cylindrical container (pot) 11 that accommodates the cable core A wound in a laminated manner therein, a lid 12 for sealing the inside of the container 11 and vacuum drying and oil impregnation; A rotation drive unit 13 is provided for sending the oil-impregnated cable core A to a lead sheath extruder 20 through a guide pipe (siphon tube) 14 filled with insulating oil. Reference numeral 15 denotes a wheel attached to the bottom of the cylindrical container 11. Reference numeral 16 denotes a pump for evacuating the inside of the guide pipe 14.
[0018]
Then, the cable core A in the cylindrical container 11 of the vacuum drying oil impregnation apparatus 10 is put, the lid 12 is closed and the inside of the container is sealed, the cable core A is vacuum dried, and the cylindrical oil is filled with the insulating oil B. Then, oil impregnation is applied to the insulating layer of the cable core A. Thereafter, the lid 12 is opened, the cable core A impregnated with oil is drawn out from the container 11 while the cylindrical container 11 is rotated by the rotation drive unit 13, and lead is passed through the guide pipe 14 filled with insulating oil by vacuum suction. It sends out toward the sheath extruder 20.
[0019]
Next, the configuration of the lead sheath extruder 20 according to the present invention will be described in detail with reference to FIG. Reference numeral 21 denotes an extrusion head serving as an extruder body, and a die 22, a nipple 23, and a nipple holder 24 that supports the nipple 23 are disposed substantially coaxially in the extrusion head 21. In addition, a lead extrusion passage 25 for extruding heat-softened lead is formed between the die 22 and the nipple 23. The lead extrusion flow path 25 is supplied with heat-softened lead from a lead supply unit 26 including an extrusion cylinder 27 and a rotary screw 28 connected to the extrusion head 21.
[0020]
A plurality of bolts 29 for finely adjusting the mounting position of the die 22 in the radial direction are disposed outside the die 22 in order to prevent unevenness of the lead sheath C. A die holder 30 is provided with a cooling water injection nozzle 31 for cooling the lead sheath C extruded from the lead extrusion flow path 25.
[0021]
The rear portion of the nipple holder 24 is held by a retainer 32, and a cable core insertion passage 33 through which the cable core A already impregnated with the vacuum drying oil impregnation apparatus 10 is inserted is formed in the nipple holder 24. .
In the cable core insertion passage 33, insulating oil circulation means 34 is provided for forcibly circulating the insulation oil B supplied into the insertion passage 33 and discharging it out of the insertion passage 33.
[0022]
The insulating oil circulation means 34 is formed between the oil passage pipe 35 disposed in the cable core insertion passage 33 and the cable core A and the oil passage pipe 35 inserted into the oil passage pipe 35. Formed between the nipple holder 24 and the oil passage 35, and the insulating oil forward passage 36 is formed between the nipple holder 24 and the oil passage pipe 35. An insulating oil return flow path 38 that circulates from the outlet side 36b of the pipe 36 through the oil communication path 37 between the oil passage pipe 35 and the nipple 23 so as to return to the direction opposite to the insertion direction of the cable core A; The cable core includes an insulating oil B supply port 39 provided on the inlet side 36a of the flow path 36 and an insulating oil B discharge port 40 provided on the outlet side 38a of the insulating oil return flow path 38. A to the insulating oil B supplied into the cable core insertion passage 33 However, it is inserted into the cable core insertion passage 33 and guided into the nipple 23 and the die 22, and lead is extruded from the lead extrusion flow path 25 to cover the outer periphery of the cable core A with the lead sheath C. Yes. Reference numeral 35a denotes an annular spacer projecting on the outer peripheral surface of the oil passage pipe 35 in order to support the tip side of the oil passage pipe 35, that is, the side close to the nipple 23 on the inner wall surface of the nipple holder 24. In order to circulate, recesses (not shown) are formed at intervals in the circumferential direction.
[0023]
The insulating oil B supply port 39 provided on the inlet side 36a of the insulating oil forward flow path 36 has a plurality of insulating oil injection nozzles 39a formed in the circumferential direction on the pipe wall of the oil passage pipe 35 and a cylinder covering the nozzle. It comprises a jacket 39b and a supply pipe 39c. An insulating oil B discharge port 40 provided on the outlet side 38 a of the insulating oil return flow path 38 is provided in the oil passage pipe so as to cover the oil passage pipe 35, and a seal packing 41 is provided at the rear portion of the nipple holder 24. It is comprised by the jacket pipe 40a and the discharge pipe 40b which are connected through this.
[0024]
In this manner, the fresh insulation oil B degassed and purified from the insulation oil injection nozzle 39a of the supply port 39 of the insulation oil forward flow path 36 is supplied into the cable core insertion passage 33, and this is supplied to the insulation oil delivery path 33. Forcibly circulate in the flow path 36, and return from the outlet side 36b (the nipple 23 side) to the reverse direction of the insertion direction of the cable core A into the insulating oil return flow path 38 via the oil communication path 37. It can be circulated and discharged out of the cable core insertion passage 33 from the discharge port 40 of the insulating oil return flow path 38.
[0025]
In addition, the rear end portion of the guide pipe 14 is connected to the rear end portion of the oil passage pipe 35 via the seal packing 42, and the insulating oil B filled in the guide pipe 14 is also supplied together. Alternatively, the insulating oil B may be supplied from the guide pipe 14 side. In such a case, the guide pipe 14 serves as the supply port 39 or becomes the supply port 39. When supplying the insulating oil B from the guide pipe 14 side, if the insulating oil B is sucked from the discharge port 40 side of the insulating oil return flow path 38, the insulating oil B is more smoothly introduced into the cable core insertion path 33. It is possible to insert through.
[0026]
The insulating oil B discharged from the discharge port 40 to the outside of the cable core insertion passage 33 may be discarded after being treated with waste oil. However, in order to effectively use resources, the insulating oil B is oil degassed and refined, although not shown. When it is refined by a device (not shown) and is at a high temperature, it is cooled to a predetermined temperature by a heat exchanger, and again in the cable core insertion passage 33 from the supply port 39 of the insulating oil forward flow path 36 by a circulation pump. It is preferable to use it for circulation.
[0027]
In the lead sheath extruder of the present invention, since the insulating oil circulation means 34 is provided, new insulating oil is supplied into the cable core insertion passage, and is forced to flow and discharged out of the insertion passage. Therefore, even if the insulating oil in the cable core insertion passage is heated by the heat of the lead sheath extrusion coating on the cable core, it can be prevented from rising to a high temperature exceeding the allowable limit.
[0028]
Further, in the present invention, a cooler 43 for reducing the temperature of the insulating oil B is provided in the insulating oil return passage 38 of the insulating oil circulation means 34. The cooler 43 is constituted by a cooling pipe coil formed by winding a cooling pipe such as a copper pipe, a brass pipe, or a SUS pipe in a coil shape, and the outer periphery of the oil passage pipe 35 near the outlet side of the insulating oil return flow path 38. It is attached to. 43a is an inlet for supplying cooling water, and 43b is an outlet for discharging the cooling water.
[0029]
By providing the cooler 43, the insulating oil whose temperature has increased in the process of flowing through the cable core insertion passage is cooled when discharged outside the cable core insertion passage. It is preferable that the temperature of the insulating oil can be reliably lowered below the flash point and the risk of fire can be further avoided.
[0030]
A vacuum heat insulating layer 44 is provided in the vicinity of the inner wall of the nipple holder 24 along the cable core insertion path 33. 44a is a vacuum suction port. By providing such a vacuum heat insulating layer 44, it is particularly effective in blocking the inflow of heat from the extrusion head on the back side (nipple side) of the cable core insertion passage 33, and the insulating oil is efficiently cooled to High temperature can be prevented.
[0031]
When the lead sheath extruder 20 according to the present invention is used, new insulating oil B deaerated and purified in advance from the insulating oil distribution means is supplied and distributed in the cable core insertion passage. Further, cooling water is supplied into the cooling coil of the cooler 43 and the vacuum heat insulating layer 44 is also kept in a vacuum state. Thereafter, the cable core A impregnated with the vacuum drying oil impregnation apparatus 10 is inserted into the cable core insertion path 33 of the present extruder through the guide pipe 14, and the cable core A is immersed in the insulating oil B while nipple, die Then, the lead is extruded from the lead extrusion flow path 25, and the lead sheath C is extrusion coated on the outer periphery of the cable core A to manufacture an OF cable.
[0032]
【The invention's effect】
As described above, in the lead sheath extruder of the present invention, the die, nipple, and nipple holder are arranged in the extrusion head, the lead extrusion flow path is formed between the die and the nipple, and the nipple holder is already impregnated with oil. Forming a cable core insertion passage through which the cable core is inserted, and immersing the cable core in the insulating oil supplied in the cable core insertion passage, guiding the cable core insertion passage through the nipple and the die, In the case where lead is extruded from the lead extrusion flow path and the lead sheath is extrusion coated on the outer periphery of the cable core, the insulating oil supplied into the cable core insertion passage is forced to flow out of the insertion passage. Even if the insulation oil in the cable core insertion passage is heated by the heat of the lead sheath extrusion coating to the cable core, it will exceed the allowable limit because it is provided with a means for circulating the insulation oil to be discharged. Without having to increase the temperature, it is possible to eliminate the fear that insulating oil and seal packing deteriorates early.
[0033]
In addition, since the temperature of the insulating oil supplied into the cable core insertion passage of the extruder does not rise above the flash point, there is no need to worry about the occurrence of a fire, making OF cable manufacturing work safer. It can be carried out.
[0034]
The front Symbol insulating oil circulation means are formed between the oil pipe disposed in the cable core insertion path, the cable core and the oil pipe to be inserted into the oil passage pipe, supplied to the cable core insertion path Is formed between the nipple holder and the oil passage pipe, and the insulating oil is passed from the outlet side of the insulation oil forward passage to the oil passage pipe. An insulating oil return flow path that circulates back through the oil communication path between the nipples in a direction opposite to the insertion direction of the cable core, and an insulating oil supply port provided on the inlet side of the insulating oil forward flow path; Insulating oil discharge port provided on the outlet side of the insulating oil return flow path allows the insulating oil to flow smoothly in the cable core insertion path. Can be more efficiently prevented.
[0035]
Further, by providing the pre-Symbol cooler to lower the temperature of the insulating oil discharged from the discharge port of the insulating oil insulating oil recovery passage of the insulating oil distribution means, temperature in the course of flowing through the cable core insertion path When the rising insulation oil is discharged out of the cable core insertion path, it will be cooled, and the temperature of the insulation oil discharged out of the cable core insertion path can be reduced more reliably, resulting in the risk of fire. Can be avoided more effectively.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a main configuration of a mass impregnation OF cable manufacturing apparatus.
FIG. 2 is a cross-sectional view showing a lead sheath extruder according to the present invention.
[Explanation of symbols]
20 Lead sheath extruder 21 Extrusion head 22 Die 23 Nipple 24 Nipple holder 25 Lead extrusion passage 33 Cable core insertion passage 34 Insulating oil circulation means 35 Oil passage pipe 36 Insulating oil forward passage 36a Inlet side 36b Outlet side 37 Oil communication passage 38 Insulating oil return flow path 38a Outlet side 39 Supply port 40 Outlet port 41 Seal packing 42 Seal packing 43 Cooler A Cable core B Insulating oil C Lead sheath

Claims (2)

Dies, nipples, nipple holders are arranged in the extrusion head, lead extrusion flow paths are formed between the dies and nipples, cable core insertion passages for inserting the cable cores already oil-impregnated into the nipple holders are formed, While immersing the cable core in the insulating oil supplied in the cable core insertion path, the cable core is inserted into the nipple and die through the cable core insertion path, and lead is extruded from the lead extrusion flow path to the outer periphery of the cable core. in the lead sheath extruder so as to extrusion coating of lead sheath, provided with the insulating oil circulation means for discharging cable core insertion path is forcibly circulated the supplied insulating oil to be outside the insertion path, the insulation The oil distribution means is formed between the oil passage pipe disposed in the cable core insertion passage, the cable core inserted in the oil passage pipe, and the oil passage pipe, and is supplied into the cable core insertion passage. It is formed between the insulating oil forward flow path that circulates the edge oil in the insertion direction of the cable core, and between the nipple holder and the oil passage pipe. An insulating oil return passage that is circulated so as to return to the direction opposite to the insertion direction of the cable core, an insulating oil supply port provided on the inlet side of the insulating oil forward passage, and an insulating oil A lead sheath extruder comprising an insulating oil outlet provided on the outlet side of the return flow path . The lead sheath extruder according to claim 1, wherein a cooler for reducing the temperature of the insulating oil discharged from the insulating oil outlet is provided in the insulating oil return flow path .

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