JP2011020263A - Mold for molding insulating tube unit and insulating tube unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold for molding an insulating tube unit, which does not need a mold clamping part under hydraulic pressure and can miniaturize an apparatus and the insulating tube unit. <P>SOLUTION: The mold 40 for molding an insulating tube unit 10 which has a cavity for molding the insulating tube unit 10 for insulating the joint of a power cable is constituted of at least three blocks 41-44 which are partitioned by parting planes arranged in the radial directions C1 and C2 of the insulating tube unit 10. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an insulating tube unit molding die and an insulating tube unit, and more particularly to an insulating tube unit molding die and an insulating tube unit that can reduce the size of a molding apparatus.

  The use of a normal temperature shrinkable insulation tube unit is widely used for insulation treatment at a place where two high-voltage power cables are connected. The product shape of the room temperature shrinkable insulating tube unit is cylindrical, and is formed of rubber such as liquid silicone rubber (LSR). When the cable connection portion is insulated by the room temperature shrinkable insulating tube unit, the diameter expansion member is inserted into the center hole and the diameter is expanded, and the cable connection portion is arranged in the cable connection portion. Thereafter, when the diameter-expanding member is removed, the tube unit is reduced in diameter and attached to the cable connection portion.

  A liquid resin injection molding method (LIM) is generally applied as a molding method for the liquid silicone rubber. In this molding method, a molding apparatus combining a material supply apparatus, an injection unit, a mold, and a mold clamping mechanism is used.

FIG. 7 shows a schematic configuration of a main part of an apparatus for forming a cold-shrinkable insulating tube unit. An upper mold 201 and a lower mold 202 divided by a plane including the central axis of the tube unit are hydraulic pistons. The mold is clamped by a mold clamping mechanism including 206, an upper mold clamping part 203, and a lower mold clamping part 204. Liquid silicone rubber is injected from the injection unit 205 into the upper mold 201 and the lower mold 202.
A mold composed of an upper mold and a lower mold as described above is disclosed in Patent Document 1.

JP 2001-268770 A

In the conventional molding apparatus shown in FIG. 8 and the molding die described in Patent Document 1, since the projected area of the molded product is large, the upper mold with a considerable clamping force (for example, several hundred to several hundreds of tons) E If the mold 201 and the lower mold 202 are not clamped, the mold opens when resin is injected from the injection unit. For this reason, a large mold clamping mechanism is required. Also, the mold must be strong enough to withstand this clamping force, and the mass of the upper mold 201 and the lower mold 202 is about 1 ton, and handling is not easy.
Accordingly, an object of the present invention is to provide a mold for forming an insulating tube unit and an insulating tube unit that can reduce the mold clamping force and reduce the size of the apparatus in order to solve the above-described problems.

In order to solve the above problems, the insulating tube unit molding die of the first invention is an insulating tube unit molding die having a cavity for molding the insulating tube unit for insulating the connection portion of the power cable. And it consists of three blocks divided | segmented by the division surface along the radial direction of the said insulation tube unit, It is characterized by the above-mentioned.
With the above configuration, the projection area can be reduced as compared with a conventional mold that is divided vertically on the plane including the central axis. As a result, the mold clamping force can be reduced, no large mold clamping is required, and the apparatus can be miniaturized.

  The mold for forming an insulating tube unit according to the second invention is characterized in that the surface of the block on the cavity side is inclined with respect to the opening direction of the mold part perpendicular to the radial direction. And According to this configuration, since the resistance when the insulating tube unit is taken out from the block cavity after molding can be reduced, the insulating tube unit can be easily removed from the cavity, and the workability is improved.

The mold for forming an insulating tube unit according to a third aspect of the invention is characterized in that the three or more blocks are assembled by being fastened together with bolts and nuts. According to this configuration, the three or more mold parts may be assembled by being fastened to each other with the bolts and nuts, so that the insulating tube unit molding operation is facilitated.
The insulating tube unit of the present invention is characterized by being molded by the first to third molds for forming an insulating tube unit. This insulating tube unit is easy to mold.

  ADVANTAGE OF THE INVENTION According to this invention, the type | mold for insulation tube unit shaping | molding and insulation tube unit which can achieve size reduction of an apparatus can be provided.

FIG. 2 is a sectional view in the axial direction showing a preferred embodiment of an insulating tube unit manufactured by the mold for forming an insulating tube unit of the present invention and showing a state in which a straight connection portion of a power cable is insulated. It is sectional drawing along the axial direction CL which shows the type | mold (henceforth a shaping | molding die) for insulation tube unit shaping | molding. It is sectional drawing which shows the state by which liquid silicone rubber was inject | poured in the cavity of the shaping | molding die of FIG. 2, and the insulating tube unit was shape | molded. It is the side view which looked at the side surface side of the 3rd block of the shaping | molding die of FIG. 2 from the F direction. It is a figure which shows the state in which the adjacent 1st block and 3rd block were mutually fastened with the volt | bolt and the nut, for example. It is sectional drawing which shows another embodiment of the type | mold for insulation tube unit shaping | molding of this invention. It is a figure which shows the conventional molding apparatus.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a preferred embodiment of an insulating tube unit manufactured by the mold for forming an insulating tube unit of the present invention, and is an axial cross-sectional view showing a state in which a straight connection portion of a power cable is insulated. is there.

  The product shape of the insulating tube unit 10 shown in FIG. 1 is a cylindrical shape, which is a laminated structure of a plurality of rubber layers, and is formed of liquid silicone rubber. The insulating tube unit 10 shown in FIG. 1 is of the normal temperature shrinkage type, and insulates the straight connection portion between the first power cable 1 and the second power cable 2.

  The first power cable 1 has an insulating sheath 5, an insulator layer 6, an external semiconductive layer 7, and a cloth tape layer or a metal shielding layer that covers the external semiconductive layer 7. Similarly, the second power cable 2 has an insulating sheath 15, an insulator layer 16, an external semiconductive layer 17, and a cloth tape layer or a metal shielding layer that covers the external semiconductive layer 17. .

  As shown in FIG. 1, the first cable conductor 3 and the second cable conductor 4 are electrically and mechanically connected by a connecting pipe 18 having conductivity. The outer periphery of the first cable conductor 3, the second cable conductor 4, and the connecting pipe 18 is covered with a semiconductive tape 19.

The periphery of the connecting portion between the first power cable 1 and the second power cable 2 is covered with an insulating tube unit 10. The insulating tube unit 10 has a cylindrical shape, and includes a reinforcing insulating layer 20, an internal semiconductive layer 30, a first stress cone 8 and a second stress cone 9. Although not shown, an outer semiconductive layer is further provided on the outer peripheral surface of the insulating tube unit 10.
In the present invention, the term “insulating tube unit” is used for both an external semiconductive layer not provided and an external semiconductive layer not provided.
The inner semiconductive layer 30, the first stress cone 8 and the second stress cone 9 are arranged coaxially along the axial direction CL. The first stress cone 8 and the second stress cone 9 are members formed using, for example, semiconductive liquid silicone rubber mixed with carbon, and have a substantially trumpet shape.

The reinforcing insulating layer 20 shown in FIG. 1 is a cylindrical member that is made of an elastic material such as an electrically insulating liquid silicone rubber that can shrink at room temperature. An inner semiconductive layer 30 is disposed on the inner periphery of the reinforcing insulating layer 20. The internal semiconductive layer 30 is a member formed into a cylindrical shape using, for example, semiconductive liquid silicone rubber mixed with carbon. The inner semiconductive layer 30 covers the first cable conductor 3, the second cable conductor 4, the connecting pipe 18, and part of the insulator layers 6 and 16. The internal semiconductive layer 30 has a large diameter portion 31 on one end side, a large diameter portion 32 on the other end side, and a small diameter portion 33 formed between the large diameter portion 31 and the large diameter portion 32.
The hollow portion 30H of the inner semiconductive layer 30 is formed along the axial direction CL. The hollow portion 30H is a through hole in which the first cable conductor portion 3, the second cable conductor portion 4, the connecting pipe 18, and the semiconductive tape 19 are accommodated when the insulating tube unit 10 is used.

Next, a forming die for forming an insulating tube unit for forming the insulating tube unit 10 shown in FIG. 1 will be described.
FIG. 2 is a cross-sectional view along the axial direction CL showing a forming die 40 (hereinafter referred to as a forming die) for forming an insulating tube unit. FIG. 3 is a cross-sectional view showing a state where an insulating tube unit is formed by injecting a raw material of liquid silicone rubber forming the reinforcing insulating layer 20 into the cavity of the mold 40 of FIG.

  The mold 40 shown in FIG. 2 has split surfaces C1, C2, and C3 along a radial direction T orthogonal to the axial direction CL, and can be divided into four blocks. Due to the divided surfaces C1, C2, and C3 formed in the radial direction T of the insulating tube unit 10, the molding die 40 has a first block 41, a second block 42, a third block 43, and a fourth block 44. It is divided into

  The first block 41 and the second block 42 are formed in a substantially bilaterally symmetric shape with the center split surface C3 of the mold 40 as the center. Moreover, the 3rd block 43 and the 4th block 44 are formed in the substantially left-right symmetric shape centering on the division surface C3 of the center. Conical cavities 51 and 52 are formed in the first block 41 and the second block 42, respectively, and the outer shape is square and has a shape with a hole penetrating through the center. In the third block 43 and the fourth block 44, substantially cylindrical cavities 53 and 54 are formed, and the outer shape is square and has a shape with a hole penetrating through the center. These cavities 51, 52, 53, and 54 are continuous spaces in which liquid silicone rubber is injected to form the reinforcing insulating layer 20 of the insulating tube unit 10 shown in FIG.

The maximum inner diameter D1 of the cavity 51 is the same as the minimum inner diameter D2 of the cavity 53. The maximum inner diameter D1 of the cavity 52 is the same as the minimum inner diameter D2 of the cavity 54. The maximum inner diameter D3 of the cavity 53 is the same as the maximum inner diameter D4 of the cavity 54.
Since the maximum inner diameter D3 (D4) of the cavity 53 is larger than the minimum inner diameter D2, the cavity 53 is formed with an inclined surface (cavity surface) 53D inclined so as to open by an inclination angle θ toward the X1 direction. 54 is formed with an inclined surface (cavity surface) 54D that is inclined so as to be opened by an inclination angle θ in the X2 direction opposite to the X1 direction. The X1 direction and the X2 direction are directions orthogonal to the divided surfaces C1, C2, and C3 (the radial direction T of the insulating tube unit 10), that is, the mold clamping direction.

  This inclination angle θ is preferably 1.5 to 1.6 degrees. When the inclination angle θ is smaller than 1.5 degrees, it is not preferable because the resistance to take out cannot be reduced when the reinforcing insulating layer 20 of the insulating tube unit 10 is taken out. When the inclination angle θ is larger than 1.6 degrees, the insulating tube is not preferred. A large tapered portion is formed in the outer peripheral shape of the reinforcing insulating layer 20 of the unit 10, which is not preferable.

  In this way, the cavities 53 and 54 are formed so as to be opposite to each other so that the reinforced insulating layer of the insulating tube unit 10 is formed from the cavity 53 of the third block 43 and the cavity 54 of the fourth block 4 after molding. This is to make it easier to pull 20 out. That is, since the silicone rubber is thermally expanded by heating for curing, a molded product of the reinforcing insulating layer 20 as a product is formed from the cavity 53 of the third block 43 and the cavity 54 of the fourth block 4 having a cylindrical cross section. Since the resistance becomes large when taking out, the cavities 53 and 54 are formed to be inclined so as to be opposite to each other in order to reduce the take-out resistance and facilitate the work.

  The cavity 51 of the first block 41 forms a taper portion 20P of the reinforcing insulating layer 20 shown in FIGS. 1 and 3, and the cavity 52 of the second block 42 is a taper of the reinforcing insulating layer 20 shown in FIGS. A portion 20R is formed. The cavity 53 of the third block 43 forms the cylindrical portion 20S of the reinforcing insulating layer 20 shown in FIGS. 1 and 3, and the cavity 54 of the fourth block 44 is the cylindrical shape of the reinforcing insulating layer 20 shown in FIGS. The part 20T can be formed. The first block 41 has a through hole 41H along the central axis CL, and the second block 42 has a through hole 42H along the central axis CL. The first power cable 1 and the second power cable 2 are inserted into the through holes 41H and 42H, respectively.

FIG. 4 is a side view of the side surface side of the third mold portion 43 of FIG. 2 as viewed from the F direction as an example.
As illustrated in FIGS. 2 and 4, the third mold portion 43 is a substantially rectangular parallelepiped member, and has first side portions 43A, 43B, 43C, and 43D as shown in FIG. Similarly to the third block 43, the first block 41, the second block 42, and the fourth block 44 are substantially rectangular parallelepiped members. Alignment holes 60 are formed in the four corner portions of the first block 41, the second block 42, the fourth block 44, and the third block 43, respectively.

  As shown in FIGS. 4 and 2, a liquid silicone rubber inlet 61 and a film gate 62 are formed in the third block 43. The film gate 62 is connected to the inlet 61 via a runner 63. The liquid silicone rubber inlet 61, the film gate 62, and the runner 63 are formed at the joint between the first block 41 and the third block 43. The film gate 62 is a circumferential film gate formed over the entire circumference of the cavity 51 of the first block 41 and the cavity 53 of the third block 43.

  On the other hand, as shown in FIG. 2, an overflow port 71, a film gate 72, and a runner (not shown) of liquid silicone rubber are formed at a joint portion between the second block 42 and the fourth block 44. The film gate 72 is a circumferential film gate formed over the entire circumference of the cavity 52 of the second block 42 and the cavity 54 of the fourth block 44.

As shown in FIG. 3, in the reinforcing insulating layer 20 to be molded, parting lines (traces of the joints of the mold parts) are formed at positions corresponding to the divided surfaces C1, C2, and C3. This parting line may be formed only in a linear shape over the entire periphery on the outer peripheral surface of the reinforcing insulating layer 20, but may also be formed in a burr shape.
Since the molding die 40 is configured to be divided into four parts by the first block 41, the second block 42, the third block 43, and the fourth block 44, the reinforcing insulating layer 20 that is an electrical insulating component is parted. The lines can be arranged on the outer peripheral portion of the central portion of the reinforcing insulating layer 20 where the electrical stress is relatively low, and on the outer peripheral portions of the first stress cone 8 and the second stress cone 9 at both ends.

Next, a method for forming the insulating tube unit 10 with the mold 40 for forming the insulating tube unit will be described.
The mold 40 is assembled by combining the first block 41, the second block 42, the third block 43, and the fourth block 44 described above. In the center hole (cavities 51, 52, 53, 54) of the mold 40, an assembly unit of the cored bar 200 to which the internal semiconductive layer 30, the first stress cone 8 and the second stress cone 9 are attached is arranged. Has been.
As shown in FIG. 2, the molding die 40 is clamped with a clamping force P by being sandwiched between the fixing plate 101 and the pressing plate 102 of the clamping device 100 having a simple structure.

  Next, when the liquid silicone rubber is injected into the liquid silicone rubber injection port 61 of the third block 43 shown in FIG. 2 through the runner 63 and the film gate 62, the liquid silicone rubber G is formed as shown in FIG. The cavity of the mold 40 is filled.

  Thereby, as shown in FIG. 3, the reinforcing insulating layer 20 covering the inner semiconductive layer 30, the first stress cone 8 and the second stress cone 9 can be formed. If the injection port 61 of the liquid silicone rubber is selected at the lowermost angle at the time of material injection, air entrainment at the time of injection can be minimized. When liquid silicone rubber is injected into the injection port 61, the air in the cavities 51 to 54 can be discharged to the outside from the discharge port 71, so that voids can be prevented from occurring in the outer peripheral portion of the reinforcing insulating layer 20. Moreover, the discharge port 71 can be removed positively by making it the top part at the time of material injection | pouring.

  After the reinforcing insulating layer 20 is formed as described above, the clamping by the fixing plate 101 and the pressing plate 102 of the clamping device 100 shown in FIG. 3 is released. Then, the first block 41, the second block 42, the third block 43, and the fourth block 44 are disassembled in the direction of the central axis CL along the dividing surfaces C1, C2, and C3. Thereby, the insulating tube unit 10 (molded product of the reinforcing insulating layer 20) is taken out.

  At the time of this removal, as shown in FIG. 3, since the cavities 53 and 54 are inclined so as to be opposite to each other, the cavity 53 of the third block 43 and the cavity 54 of the fourth block 4 are The insulating tube unit 10 (molded product of the reinforcing insulating layer 20) can be easily pulled out after molding. That is, since the silicone rubber is thermally expanded by heating for curing, the reinforcing insulating layer 20 of the insulating tube unit 10 that is in close contact with the inner surface of the cavity can be easily peeled off, and this take-out resistance is reduced. Work can be facilitated.

In this way, the reinforcing insulating layer 20 is formed. On the outer peripheral surface of the reinforcing insulating layer 20, the parting lines are transferred along the entire circumference along the divided surfaces C1, C2, and C3. The parting line can be removed by polishing.
And it is diameter-expanded in a factory and is carried to a construction site in the state which inserted the diameter-expansion member in the center hole.

As shown in FIG. 2, the molding die 40 is clamped with a clamping force P by being sandwiched between the fixing plate 101 and the pressing plate 102 of the clamping device 100. The mold clamping force P at this time can be set smaller than in the prior art.
Liquid silicone rubber expands thermally by heating for curing. For this reason, in the conventional example shown in FIG. 8, since the upper mold 201 and the lower mold 202 are opened in the vertical division direction at the time of molding, the upper mold clamping part 203 and the lower mold clamping part 204 are connected to the hydraulic piston. It is necessary to clamp the upper mold 201 and the lower mold 202 with a strong force using 206.

  On the other hand, since the mold 40 according to the embodiment of the present invention employs a structure that divides the central axis CL direction in the left-right direction, the force applied in the direction divided in the left-right direction due to thermal expansion of the silicone rubber. Therefore, the mold clamping force P can be made smaller than the conventional mold clamping force.

Next, with reference to FIG. 5, the modification of the shaping | molding die of the said embodiment is demonstrated.
In this mold, as shown in FIG. 5, hooks are provided on the outer circumferences of the first block 41 and the third block 43 adjacent to each other in the embodiment, and these are fastened to each other by, for example, bolts 75 and nuts 76. Similarly, the third block 43 and the fourth block 44, and the fourth block 44 and the second block 42 are fastened to each other by a bolt 75 and a nut 76.
The reason that the bolts can be clamped in this way is because the blocks 41, 42, 43, and 44 are divided by the dividing surfaces C1, C2, and C3 along the radial direction. That is, the projection of the reinforcing insulating layer in the case of a mold in which the projected area of the reinforcing insulating layer 20 in the direction in which the blocks 41, 42, 43, 44 are closed (clamping direction) opens up and down with respect to the conventional center line CL. This is because the clamping force is small because it is smaller than the area.
Thus, if the four blocks 41, 42, 43, 44 are detachably fastened to each other with bolts and nuts, it is not necessary to perform mold clamping by hydraulic pressure, so that the molding apparatus can be simplified and a large number of molding dies can be used. It can be used to improve productivity.

Next, another embodiment of the mold of the present invention will be described with reference to FIG.
FIG. 6 is a cross-sectional view showing another embodiment of the mold of the present invention.
In the above-described embodiment of the present invention shown in FIGS. 2 and 3, the mold 40 is composed of four blocks.
On the other hand, the forming die 80 for forming the insulating tube unit shown in FIG. 6 is configured by combining three blocks, that is, a first block 81, a second block 82, and a third block 83.

  The mold 80 is made of a metal such as aluminum. The mold 80 has split surfaces C4 and C5 along a radial direction T perpendicular to the axial direction CL, and can be divided into three blocks.

  The first block 81 and the second block 82 are formed in a substantially bilaterally symmetric shape. Conical cavities 91 and 92 are formed in the first block 81 and the second block 82, respectively. A substantially cylindrical cavity 83 is formed in the third block 83. These cavities 91, 92, 93 are spaces for injecting liquid silicone rubber to form the reinforcing insulating layer 20A of the insulating tube unit 10A shown in FIG.

  The maximum inner diameter D1 of the cavity 91 is the same as the minimum inner diameter D2 of the cavity 93. The maximum inner diameter D5 of the cavity 92 is the same as the maximum inner diameter D6 of the cavity 93. Accordingly, the cavity 93 is formed with an inclined surface 93D so as to open by an inclination angle θ toward the X1 direction.

This inclination angle θ is preferably 1.5 to 1.6 degrees. If the inclination angle θ is smaller than 1.5 degrees, it is not preferable because the extraction resistance cannot be reduced when taking out the reinforcing insulating layer 20A of the insulating tube unit 10A. If the inclination angle θ is larger than 1.6 degrees, the insulation tube is not preferred. A large taper is formed in the outer peripheral shape of the reinforcing insulating layer 20A of the unit 10A, which is not preferable.
The reason why the cavity 53 is formed so as to be inclined is that it is easy to pull out the reinforcing insulating layer 20A of the insulating tube unit 10A from the cavity 93 of the third block 83 after molding.

The cavity 91 of the first block 81 forms a tapered portion 20P of the reinforcing insulating layer 20A shown in FIG. 6, and the cavity 92 of the second block 82 forms the tapered portion 20R of the reinforcing insulating layer 20A shown in FIGS. Form. The cavity 93 of the third block 83 can form the cylindrical portion 20S of the reinforcing insulating layer 20A. The first block 81 has a through hole 41H along the central axis CL, and the second mold portion 82 has a through hole 42H along the central axis CL.
The first block 81, the second block 82, and the third block 83 are substantially rectangular parallelepiped members. Alignment holes are formed in the four corners of each mold part.

  As shown in FIG. 6, a liquid silicone rubber inlet 61 and a film gate 62 are formed in the third block 83. The film gate 62 is connected to the inlet 61 via a runner (not shown). The liquid silicone rubber inlet 61, the film gate 62, and the runner are formed at the joint portion of the first mold portion 81 and the third mold portion 83.

  On the other hand, an overflow port 71, a film gate 72, and a runner (not shown) of liquid silicone rubber are formed at a joint portion between the second block 82 and the third block 83.

As shown in FIG. 3, a parting line is formed at a position corresponding to the divided surfaces C5 and C6 in the formed reinforcing insulating layer 20A. The parting line may be formed in a linear shape all around the outer peripheral surface of the reinforcing insulating layer 20A, but may be formed in a burr shape.
The parting line of the mold 80 is disposed on the outer peripheral portion of the central portion of the reinforcing insulating layer 20A where the electrical stress is relatively low, and on the outer peripheral portions of the first stress cone 8 and the second stress cone 9 at both ends. be able to.
The structure shown in FIG. 5 may be adopted as means for clamping adjacent blocks.

  The mating part of each block is a connecting part called a parting line, but there is an unnecessary part on the product called a burr at the position of the insulating tube unit corresponding to the connecting part. Processing is required. Since these parting lines are accompanied by the entrance and exit of the material at the time of molding, there are cases in which residual stress is likely to occur, product function such as easy to see the flow of material called flow mark, and product appearance quality problems may occur. is there.

  Therefore, in order to solve such a problem, in the molding die of the present invention, three or more blocks are divided along the radial direction of the insulating tube unit. This makes it possible to design molds that take into account product functions and product appearance. The inlet and outlet of the material may be provided at any position on the parting line, and the inlet can be selected at the lowest angle when injecting material, minimizing air entrainment during injection. it can. Similarly, the air outlet can be positively removed by setting the discharge port to the top when injecting material. The shape of the material inlet and outlet can be either a round or square gate or a film gate.

By the way, this invention is not limited to the said embodiment, A various modified example is employable.
For example, the number of mold parts constituting the mold can be selected according to the length, diameter, etc. of the insulating tube unit, and the number of mold parts may be five or more.
Moreover, although the said embodiment demonstrated and demonstrated the insulating tube unit and shaping | molding die which are not provided with the external semiconductive layer, the insulating tube unit may be provided with the external semiconductive layer. For example, an insulating tube unit in which an outer semiconductive layer is formed into a cylindrical shape with silicone rubber on the outer peripheral surface of the reinforcing insulating layer may be used. In the case of manufacturing an insulating tube unit in which such an external semiconductive layer is formed, the following is performed. That is, first, a reinforcing insulating layer is formed as shown in FIG. Next, this is set in a mold having a slightly larger cavity. Next, a silicone resin mixed with carbon black is injected into the space between the mold and the reinforcing insulating layer 20 to form an external semiconductive layer.
The molding die and molding method of the present invention are applied to products other than the insulating tube unit, particularly products molded by the liquid resin injection molding method, in which the area of the longitudinal section is smaller than the area of the cross section. Can do.

DESCRIPTION OF SYMBOLS 10 Insulation tube unit 20 Reinforcement insulation layer 30 Internal semiconductive layer 40 Mold for insulation tube unit molding 41 1st block 42 2nd block 43 3rd block 44 4th block 51-54 Cavity C1-C3 Split surface (insulation tube unit 10 radial direction)
CL Center axis θ Tilt angle

Claims (4)

  A mold for forming an insulating tube unit having a cavity for forming an insulating tube unit for insulating a connection portion of a power cable, the mold being divided by three dividing surfaces along a radial direction of the insulating tube unit A mold for forming an insulating tube unit characterized by comprising a block.   The surface on the cavity side of the block is an inclined surface with respect to the opening direction of the mold part orthogonal to the radial direction, for forming an insulating tube unit according to claim 1. Type.   2. The mold for forming an insulating tube unit according to claim 1, wherein the three or more blocks are assembled by being fastened together with bolts and nuts.   An insulating tube unit formed by the mold for forming the insulating tube unit according to any one of claims 1 to 3.

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