JP2003009370A - Manufacturing method for cylindrical member of polymeric material for cable connection - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with metal molding and enhance energy efficiency for the reduction of manufacturing cost of a cylindrical member of polymeric material for cable connection. SOLUTION: A mandrel 16 is turned in a reservoir 18 filled with a polymer material 17, which absorbs electromagnetic waves and is thereby cured. At the same time, electromagnetic waves are irradiated to a specified area from an electromagnetic wave irradiating apparatus 19 for curing and sticking a specified portion of the polymer material 17 to the outer circumferential surface of the mandrel 16. Finally, the mandrel 16 is pulled out to obtain a cylindrical member of polymer material for cable connection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a termination for connecting, for example, a straight connecting portion for connecting ends of cable conductors constituting a power cable or for connecting the ends of a power cable to terminals of various electric power equipment. The present invention relates to an improvement in a manufacturing method of a tubular insulator such as a prefabricated mold insulator or a premolded insulator for forming a connecting portion. In particular, the present invention aims at cost reduction by enabling such a tubular insulator to be efficiently manufactured without requiring expensive equipment.

[0002]

2. Description of the Related Art A polymer material such as rubber, which is an elastic material, is used as a structure for relatively easily connecting the end portions of a power cable or connecting the end portion of the power cable and a terminal of various power devices. The prefabricated mold insulator made by or the premolded insulator covers the cable conductors forming a pair of power cables, or the structure for covering the connection between the end of this power cable and the terminal of various power equipment. Are known. For example, FIGS. 7 to 8 show two examples of premolded insulators for forming a terminating connection part which is a connection part between an end part of a power cable and a terminal of various power devices.

Of these, the pre-molded insulator 1 of the first example shown in FIG. 7 is integrally made of insulating rubber and has a central hole 2 having a circular cross section that penetrates in the axial direction.
Further, in order to relieve the electric field of the shield electrode in the portion near the base end of the middle portion of the outer peripheral surface (close to the end on the power cable side when assembled to the termination connection part, close to the right end in FIG. 3), the base end side The bell mouth portion 3 having a conical convex shape is provided so as to be inclined in a direction in which the outer diameter becomes smaller toward. Further, the outer peripheral surfaces of both ends of the premolded insulator 1 are inclined surfaces that are inclined in a direction in which the outer diameter decreases toward the opening edge.

The premolded insulator 4 of the second example shown in FIG. 8 is formed by providing a semiconductive layer 6 made of semiconductive rubber on a part of a body 5 made of insulating rubber, and penetrating in the axial direction. It has a central hole 7 having a circular cross section. A cylindrical surface portion 8 is provided on the outer peripheral surface of the intermediate portion of the main body 5, and a plurality of ridges 9 and 9 are formed on the cylindrical surface portion 8 to serve as clues (anti-slip) during work. Further, on both sides of the cylindrical surface portion 8, taper surface portions 10a and 10b are formed, the outer diameters of which become smaller as the distance from the cylindrical surface portion 8 increases, and the smaller diameter side end portions of one (the right side in FIG. 8) tapered surface portion 10a are formed. To form a second cylindrical surface portion 11.

Each of the premolded insulators 1 and 4 shown in FIGS. 7 to 8 is fitted onto the end portion of the power cable when the end portion of the power cable is connected to the terminals of various power equipment.
Configure the connection. In addition, which of the premolded insulators 1,
4 is also made by injection molding a polymer material such as rubber.

Further, the room-temperature shrinkable premolded insulator 12 for relatively easily connecting the ends of the power cable is constructed as shown in FIG. 9, for example. The pre-molded insulator 12 is made of rubber, which is a kind of polymer material, and has a cylindrical shape. The pre-molded insulator 12 is formed on the inner peripheral surface portion of the insulating cylindrical portion 13 made of rubber having an insulating property at an axially intermediate position.
Embedding an inner semiconductive layer 14 made of rubber having semiconductivity,
The outer peripheral surface is covered with an outer semiconductive layer 15 made of rubber having semiconductivity.

The inner diameter of the premolded insulator 12 in the free state is smaller than the outer diameter of the cable insulator of the power cable connected using the premolded insulator 12. Such a pre-molded insulator 12 elastically expands its diameter and is externally fitted to a cylindrical expanding jig not shown,
Prior to connecting the ends of the cable conductors of the pair of power cables to be connected, the power cables are fitted on the intermediate portion of one of the power cables. Then, after connecting the ends of the cable conductors of the pair of power cables, the pre-molded insulator 12 is moved to a position where the pre-molded insulator 12 is hung between the cable insulators forming the pair of power cables. Then, the diameter expanding jig is pulled out from the inner diameter side of the premolded insulator 12.

In this way, as the diameter-expanding jig is pulled out from the inner diameter side of the pre-mold insulating body 12, the pre-mold insulating body 12 contracts due to its own elasticity, and inside the both end portions of the pre-mold insulating body 12. The peripheral surface is elastically brought into contact with the outer peripheral surface of the end portion of the cable insulator that constitutes each of the power cables.

To make the above-mentioned premolded insulator 12 which constitutes the linear connection portion of the power cable as described above, FIG.
As shown in FIG. 0, the outer peripheral surface of the mandrel 16 and the inner peripheral surface of the molding die are inserted into a molding die (not shown) with a circular rod-shaped mandrel (core) 16 inserted into the molding die. The rubber material is filled in the cavity existing between the and. In this case, since the rubber material forming the insulating tubular portion 13 and the rubber material forming the inner semiconductive layer 14 and the outer semiconductive layer 15 are different from each other, the molding operation of the premold insulator 12 is As shown in FIG. 11, the process is divided into three steps.

That is, first, as a first step, a semiconductive rubber material is injected into a first cavity provided by a first mold (not shown) in a portion facing the outer peripheral surface of the intermediate portion of the mandrel 16. Then, heat this rubber material and
As shown in FIG. 1 (A), the inner semiconductive layer 14 is formed. Next, after cooling the inner semiconductive layer 14, the first mold is removed, and then the second step is performed. In the second step, a second mold (not shown) is provided on the outer peripheral surface of the inner semiconductive layer 14 and the portion of the inner semiconductive layer 14 exposed from both axial ends of the mandrel 16 facing the outer peripheral surface. Then, an insulating rubber material is injected into the second cavity and then the rubber material is heated to form the insulating cylinder portion 13 as shown in FIG. 11 (B). Next, after cooling the insulating cylinder portion 13, the second mold is removed, and then the third step is performed. In this third step, the inside of the third cavity provided by a third mold (not shown) on the outer peripheral surface of the insulating cylindrical portion 13 and the portion exposed from the insulating cylindrical portion 13 facing the outer peripheral surface of the mandrel 16. Then, a semiconductive rubber material is injected, and this rubber material is heated to form the outer semiconductive layer 15. Then, in the final fourth step, after cooling the outer semiconductive layer 15, the mandrel 16 is attached to the inner semiconductive layer 14 and the insulating tubular portion 1.
3 and the outer semiconductive layer 15 are removed from the inside to complete a premolded insulator 12 as shown in FIG.

[0011]

When the premolded insulators 1, 4, 12 are manufactured by the conventional manufacturing method, it is inevitable that the cost will increase. First, there are a plurality of types of premolded insulators 1 and 4 shown in FIGS. 7 to 8 having different diameters and lengths according to the outer diameter of the power cable to be connected and the voltage to be insulated. When the above-mentioned pre-mold insulators 1 and 4 are manufactured by the conventional method, it is necessary to use different molds for each of these dimensions, so the manufacturing cost of the mold increases, and the above-mentioned pre-mold insulators 1 and 4 are made. The price will increase.

Also, the premolded insulator 12 shown in FIG.
10 to 11, it is necessary not only to use different molds for each premold insulator 12 having different dimensions, but also to use the first metal mold for molding the inner semiconductive layer 14. It is necessary to prepare three types of molds, a mold, a second mold for molding the insulating tubular portion 13, and a third mold for molding the outer semiconductive layer 15. Moreover, cooling and heating must be repeated each time the first to third steps are performed. Preparing three types of molds causes a cost increase due to an increase in processing cost of each mold. Further, repeating cooling and heating not only causes an increase in energy consumption due to a decrease in energy efficiency, but also causes a cost increase due to a decrease in production efficiency due to a longer working time. Such a problem also occurs when the premolded insulator 4 having the semiconductive layer 6 therein is formed as shown in FIG. The method for manufacturing a tubular member made of a polymer material for cable connection according to the present invention was invented in view of such circumstances.

[0013]

The method for producing a tubular member made of a polymeric material for cable connection according to the present invention is a tubular member made of a polymeric material for cable connection, which is made of a polymeric material and is generally cylindrical. Is a manufacturing method. In particular, in the method for producing a tubular member made of a polymeric material for cable connection of the present invention, the polymeric material is cured by applying a curing factor selected from electromagnetic waves, heat, and cooling, and is thus cured from a liquid. Use a solid phase change material. Then, while rotating the mandrel having the outer peripheral surface as a cylindrical surface, the above-mentioned curing factor is applied to a part of the liquid polymer material existing around the mandrel to cure the polymer material. Further, while gradually moving the portion to which the hardening factor is applied in the axial direction of the mandrel and gradually moving away from the outer peripheral surface of the mandrel, a shape corresponding to the trajectory of the portion to which the hardening factor is applied around the mandrel. Forming a tubular member having. Then, the mandrel is pulled out from the central portion of the tubular member.

[0014]

According to the method of manufacturing the tubular member for polymer material for cable connection of the present invention configured as described above, the polymer material for cable connection is used without using a plurality of molds for forming the cavity. It is possible to perform the forming work of the tubular member. Also, when a tubular member made of a polymeric material for cable connection, in which different polymeric materials are stacked in multiple layers, is manufactured, it is not necessary to perform cooling each time the process is moved, and energy efficiency can be improved.
Thus, according to the method for producing a tubular member made of a polymeric material for cable connection of the present invention, the cost of the tubular member made of a polymeric material for cable connection can be reduced.

[0015]

1 to 3 show a first example of an embodiment of the present invention corresponding to claims 1 and 2. As shown in FIGS. 1 to 3, the manufacturing method of the polymer-made tubular member for cable connection of the present example is based on a circular rod-shaped mandrel 16 having an outer peripheral surface as a cylindrical surface. While rotating in a storage tank 18 in which a liquid polymer material 17 is stored, a predetermined portion of the polymer material 17 is irradiated with electromagnetic waves by an electromagnetic wave irradiation device 19, and the polymer material 17 undergoes a phase change (curing) into a solid. There is a point to let. As the polymer material 17 that undergoes a phase change from a liquid to a solid having elasticity at room temperature upon irradiation with electromagnetic waves, various conventionally known materials can be used, but a rubber material containing silicon resin as a main component can be preferably used. . As the electromagnetic wave emitted by the electromagnetic wave irradiating device 19, one selected from heat rays such as infrared rays or ultraviolet rays depending on the characteristics of the polymer material 17 used is selected and used.

In order to cure only a desired portion of the polymer material 17 stored in the storage tank 18 by the electromagnetic waves emitted from the electromagnetic wave irradiation device 19, the electromagnetic wave irradiation device 19 is designed as follows. As shown in FIG. 2, a pair of illuminators 20 and 20 are provided. Electromagnetic waves are emitted from the respective illuminators 20, 20 from different angles in directions intersecting with each other. Then, the polymer material 17 is cured only at the portions where the electromagnetic waves emitted from the respective irradiators 20, 20 intersect. That is, the energy of the electromagnetic wave is set to a value sufficient to cure the polymer material 17 only at the intersecting portions. Therefore,
Of the polymer material 17 stored in the storage tank 18, the polymer material 17 existing only in the portion through which the electromagnetic wave emitted from the one irradiator 20 passes does not cure. Further, the electromagnetic wave irradiation device 19 is the mandrel 1
6 is movable in the axial direction, and the range in which the polymer material 17 is cured by the movement of the mandrel 16
It is adjustable in the axial direction. In the following explanation,
Irradiating electromagnetic waves means that the polymer material 1 is applied at a portion where the electromagnetic waves emitted from the irradiators 20, 20 intersect each other.
7 refers to the state in which sufficient energy is applied to cure. Although not shown, only one irradiator is used and only the focal portion of the electromagnetic wave emitted from this irradiator using the lens system is in the energy state necessary for curing the polymer material. You can also In this case, the energy applied state at the focal point means that electromagnetic waves are emitted.

Using the mandrel 16 rotating in the storage tank 18 as described above and the electromagnetic wave irradiation device 19 as described above, the premolded insulator 1 as shown in FIG. 7 is prepared. While the mandrel 16 is rotated in the storage tank 18, the polymer material 17 in the storage tank 18 is irradiated with electromagnetic waves, and the electromagnetic wave irradiation device 19 is moved in the axial direction of the mandrel 16. As a result, the polymer material 17 is hardened from the vicinity of the outer peripheral surface of the mandrel 16. Therefore, if the portion to be irradiated with the electromagnetic wave is gradually moved to a portion away from the outer peripheral surface of the mandrel 16, the thickness of the polymer material 17 which is hardened around the mandrel 16 and adhered to the periphery is gradually increased. .

As described above, as the thickness of the polymer material 17 adhered to the mandrel 16 hardens around the mandrel 16 and increases, the portion irradiated with the electromagnetic wave gradually becomes the outer peripheral surface of the mandrel 16. From the radial direction to the outside in the radial direction, and the amount of movement of the electromagnetic wave irradiation device 19 in the axial direction of the mandrel 16 is reduced. If these series of operations are performed according to the shape of the premolded insulator 1 to be produced, the premolded insulator 1 can be formed around the mandrel 16 as shown in FIG. Therefore, finally, if the mandrel 16 is pulled out from the center of the cured polymer material 17, the premolded insulator 1
Can be obtained. This work is performed with the mandrel 16 removed from the storage tank 18.

The first example described above is the electromagnetic wave irradiation device 19 described above.
Is moved in the axial direction of the mandrel 16, but as shown in FIG. 4, if the width of irradiating the electromagnetic wave by the electromagnetic wave irradiating device 19a is lengthened, the work of forming the premolded insulator 1 can be made more efficient. . In this case, the width of irradiating the electromagnetic wave by each of the irradiators 20, 20 constituting the electromagnetic wave irradiating device 19a can be adjusted by the variable length slit 21. That is, when the irradiation width is widened, as shown in FIG.
When the variable length slit 21 is made longer and also made narrower as shown in FIG. 11, it is shortened as shown in FIG. When such an electromagnetic wave irradiation device 19a is used, in the initial stage of the manufacturing operation, the variable length slit 21 is elongated as shown in FIG. Irradiate long areas. On the other hand, as the manufacturing work progresses, the variable length slit 21 is shortened, and as shown in FIG. 4 (B), a portion apart from the outer peripheral surface of the mandrel 16 and shorter in the axial direction is irradiated.

In order to cure only a desired portion of the polymer material 17 stored in the storage tank 18, instead of the electromagnetic wave irradiation device 19 shown in FIGS. It is also possible to use an optical fiber. In this case,
The tip of the optical fiber is inserted into a portion of the storage tank 18 where the polymer material 17 is to be cured. Then, the tip end portion of the optical fiber is moved in the axial direction of the mandrel 16, and is displaced outward in the radial direction of the mandrel 16 as the work of forming the premolded insulator 1 progresses. Further, as a means for supplying the polymer material 17 to the outer peripheral surface of the mandrel 16, a storage tank 18 as shown in FIG.
Besides, it is also possible to adopt another method such as jetting or discharging from a nozzle. Whether the supply state from the nozzle is by injection or discharge is determined by the viscosity of the polymer material.

In this case, if the temperature of the polymer material 17 supplied from the nozzle is raised to near the crosslinking temperature, the fluidity of the polymer material 17 is increased and the handleability of the polymer material is improved. At the same time, the energy of electromagnetic waves required to cure the polymer material 17 can be kept low. Then, the time until curing can be shortened, and the manufacturing work of the premolded insulator 1 can be made more efficient. As the polymer material 17, in addition to a material that cures by absorbing electromagnetic waves, a thermosetting material that absorbs heat and cures, and a heat-melting material that cures with a decrease in temperature is used. You can also do it. When a thermosetting material is used, the polymer material supplied from the nozzle to the outer peripheral surface of the mandrel 16 is heated and attached around the mandrel 16 as shown in FIG. Get body 1. In addition, while precipitating the polymer material in which the heat-meltable polymer material is supplied from the nozzle to the outer peripheral surface of the mandrel 16 while cooling the polymer material, as shown in FIG. To get Alternatively, when a thermosetting polymer material is used, the tip of the heat pipe is inserted into the storage tank 18 in which the liquid polymer material 17 is stored as in the case of FIG. By heating a desired portion of the polymer material 17 at the tip of the pipe, the polymer material 17 is attached to the periphery of the mandrel 16 as shown in FIG.
You can also get

Next, FIG. 5 shows a second example of the embodiment of the present invention corresponding to claims 1, 2, and 4. This example shows the case where the present invention is applied to the production of the premolded insulator 4 in which the semiconductive layer 6 is embedded in the body 5 made of an insulating material as shown in FIG. ing. In the case of this example as described above, the element 22 that is separately manufactured to form the semiconductive layer 6 is embedded in the main body 5 in the process of manufacturing the main body 5 from a polymer material made of an insulating material. . That is, FIG.
As shown in (A), the inner diameter portion 23 of the main body 5 is
At the stage of forming by the same method as in the case of the first example described above,
The element 22 is fitted onto one end of the inner diameter portion 23. Then, the outer diameter portion of the main body 5 is formed again in the same manner as in the case of the first example, and the element 22 is embedded in the main body 5 as shown in FIG. 5C. . Finally, the mandrel 16 is pulled out to obtain the premolded insulator 4.

It should be noted that the element 22 is provided with a portion 23 near the inner diameter.
It is necessary to join the inner peripheral surface of the element 22 and the outer peripheral surface of the inner-diameter-approximated portion 23 after external fitting to one end of the element. Therefore, when the insulating polymer material forming the main body 5 is hardened by absorbing an electromagnetic wave, the element 22 allows the electromagnetic wave to pass therethrough, except when bonded by an adhesive. Must be one. Therefore, as the element 22, a transparent or translucent element as shown in FIG. 6A is used, or as shown in FIG. 6B,
A braided carbon fiber is used.

Further, in the above description, the semiconductive layer 6 is
Although the element 22 made separately is externally fitted, as described in claim 3, not only the main body 5 but also the semiconductive layer 6 is hardened by being given a hardening factor. Alternatively, the main body 5 and the semiconductive layer 6 may be formed in a predetermined shape in a predetermined portion in the front and rear direction while rotating the mandrel 16 for both. That is, as shown in FIG. 5A, at the stage where the inner diameter portion 23 of the main body 5 is formed, the semiconductive layer 6 is formed.
Are formed around one end of the inner diameter portion 23 by a similar method. Then, again in a similar manner, the body 5
5C, the element 22 is embedded in the main body 5 as shown in FIG. 5C.

According to the method for producing a tubular member made of a polymeric material for cable connection of the present invention which is carried out as described above, the polymeric material for cable connection is used without using a plurality of molds for forming the cavity. It is possible to perform the forming work of the tubular member.
Further, even if the shape and size of the polymer-made tubular member for cable connection to be made changes, the electromagnetic irradiation devices 19 and 19a
For example, the pattern for displacing the member that imparts the hardening factor is changed, and if necessary, the mandrel 16 having a different outer diameter can be used. It is possible to easily change the pattern for displacing the member which gives the hardening factor by changing the setting of the NC control device, and it is also easy to prepare a plurality of mandrels 16 in the shape of a circular rod. Therefore, it is possible to manufacture a plurality of types of tubular members made of a polymer material for cable connection at a relatively low cost.

Further, even when a tubular member made of a polymeric material for cable connection having a plurality of layers is manufactured, the polymeric material constituting each layer is adhered to a predetermined portion while the electromagnetic wave irradiation device 1 is provided.
Since it is cured by irradiating electromagnetic waves with 9 and 19a, it is not necessary to perform cooling each time the process is moved, and energy efficiency can be improved.

[0027]

EFFECT OF THE INVENTION Since the method for producing a tubular member made of a polymeric material for cable connection of the present invention is constructed and operates as described above, the production of the tubular member made of a polymeric material for cable connection is cost-effective. It can be done efficiently without using a bulky mold. Therefore, it is possible to reduce the cost of the tubular member made of a polymer material for connecting cables.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a perspective view showing a state before the mandrel is pulled out from the produced cylindrical member made of a polymer material for cable connection.

FIG. 4 is a schematic perspective view showing another example of the electromagnetic wave irradiation device in a state where the irradiation width is wide and a state where the irradiation width is narrowed.

FIG. 5 is a schematic perspective view of a main part showing a second example of the embodiment of the present invention in the order of steps.

FIG. 6 is a schematic perspective view showing two examples of elements for forming a semiconductive layer.

FIG. 7 is a schematic perspective view showing a first example of a premolded insulator, which is a tubular member made of a polymer material for cable connection, which is a target of the present invention.

FIG. 8 is a schematic perspective view showing the second example.

FIG. 9 is a half cutaway side view of a room temperature shrinkable tube which is a tubular member made of a polymer material for cable connection, which is a target of the present invention.

FIG. 10 is a half cutaway side view showing a state before the mandrel is extracted from the cold-shrinkable tube manufactured by the conventional manufacturing method.

FIG. 11 is a cross-sectional view illustrating a conventional manufacturing method in the order of steps.

[Explanation of symbols]

1 Pre-molded insulator 2 central hole 3 Bell mouth part 4 Pre-molded insulator 5 body 6 Semi-conductive layer 7 Center hole 8 Cylindrical surface 9 ridges 10a, 10b Tapered surface portion 11 Second cylindrical surface part 12 Pre-molded insulator 13 Insulation cylinder 14 Internal semiconductive layer 15 External semiconductive layer 16 Mandrel 17 Polymer materials 18 Storage tank 19, 19a Electromagnetic wave irradiation device 20 illuminator 21 Variable length slit 22 elements 23 Inner part

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29L 31:34 B29L 31:34 F term (reference) 4F205 AA36 AA44 AC05 AD05 AE03 AG09 AH33 AK03 GA08 GB01 GC01 GF03 GF41 GN02 GN07 GN13 4F213 AA33 AA45 AH34 WA25 WA97 WL03 WL12 WL22 5G355 AA03 BA02 BA11 5G375 AA02 BA26 BB43 CA02 CA14 CB07 DB32 EA17

Claims (4)

[Claims] 1. A method for manufacturing a tubular member made of a polymeric material, which is made of a polymeric material and has a substantially cylindrical shape as a whole, for cable connection, wherein a hardening factor is added to the polymeric material. By using a material that hardens and undergoes a phase change from liquid to solid, by rotating the mandrel with the outer peripheral surface being a cylindrical surface and imparting the hardening factor to the liquid polymer material existing around this mandrel, By curing the molecular material and adjusting the portion that imparts this curing factor with respect to the axial direction of the mandrel, by gradually moving away from the outer peripheral surface of this mandrel, the trajectory of the portion that imparts the above curing factor around the mandrel is obtained. A method for producing a tubular member made of a polymeric material for cable connection, which comprises forming a tubular member having an appropriate shape and then removing the mandrel from a central portion of the tubular member. 2. The method for producing a tubular member made of a polymeric material for cable connection according to claim 1, wherein the polymeric material is hardened by a hardening factor selected from electromagnetic waves, heat and cooling. . 3. A tubular member made of a polymeric material for cable connection, wherein a semiconductive layer is provided on a part of a main body made of an insulating material, and the main body and the semiconductive layer are given a hardening factor. The material is composed of a material that hardens on the basis of a phase change from a liquid to a solid, and the main body and the semiconductive layer are formed in a predetermined shape in a predetermined portion in a front-back direction while rotating the mandrel. A method for producing a tubular member made of a polymer material for cable connection according to any one of 1 and 2. 4. A polymer-made tubular member for connecting a cable, wherein a semiconductive layer is provided on a part of a body made of an insulating material, and an element manufactured separately to constitute this semiconductive layer is formed. The method for manufacturing a tubular member made of a polymeric material for cable connection according to any one of claims 1 to 2, wherein the main body is embedded in the main body in a process of making the polymeric material made of an insulating material.