JPH1040757A - Clamp insulator cover and manufacture thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate mounting and removing work, protect a clamp insulator from damages due to mechanical external force, and prevent short-circuiting due to contact with the clamp insulator, a strap, and another charged material. SOLUTION: For a cylindrical cover main body 11 made of electric insulation synthetic resin and decided circumferentially, an engagement portion 12 to be protruded outwardly in a radial direction together with both end portions in the circumferential direction of the cover main body 11 and group portion 13 protruded outwardly in the radial direction from an intermediate portion between circumferential both end portions of the cover main boy 11 are formed. The engagement portion 12 has a male engagement piece 15b elastiall abutting with each other and expanding in a direction distant each other at each play end portion that is the most distant from the cover main body 11 and a female engagement piece 15a. Here, the grip portion 13 is gripped, each of the engagement pieces 15a and 15b are seen on clamp insulators 3a and 3b and pushed as they are, and whereby the cover main body 11 is engagingly attached to the insulators 3a and 3b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal insulator which is connected to the arm of a telephone pole at the time of live-line construction. The present invention relates to an insulator cover and a method for manufacturing the same, which are used for protecting and preventing a short circuit caused by contact of a charged article with the insulator and the strap.

[0002]

2. Description of the Related Art FIG. 11 is a perspective view showing a protection state of traction insulators 83a and 83b using a typical prior art insulating sheet 86. FIG. Two retaining insulators (hereinafter may be abbreviated as “insulators”) 83 a and 83 b are connected by straps 85 to arm members 84 fixed to the utility pole 81 with mounting hardware such as bolts and nuts. The arm 84 and the strap 85 are made of conductive metal, and the insulators 83a and 83b are made of electrically insulating hard porcelain. One end of an electric wire 82a, which is a distribution line connected to the electric pole 81 by a wrapping wire 82b, is locked by one insulator 83a, and this one insulator 83a is connected to the other insulator 83b fixed to the strap 85. Is done. These insulators 8
3a and 83b have a predetermined creepage distance between the electric wire 82a and the strap 85, and the surface insulation resistance of each of the insulators 83a and 83b over the predetermined creepage distance causes the electric wire 82a
The wire 82a is fastened to the utility pole 81 in an electrically insulated state.

[0003] Therefore, when performing live-line work involving edging and edge connection work, insulation made of a synthetic resin having an electrical insulating property, for example, ethylene vinyl acetate copolymer (abbreviation: EVA; Echylene Vinylacetate Copolymer). A sheet 86 is wound around each of the insulators 83a and 83b and the strap 85 to provide an electrically insulating adhesive tape 8
7, for example, the electric wire 82 for edging
b, a tool that is charged by contact with the electric wire 82b, or a tool that is in contact with the electric wire 82b, or the electric wire 82b that has been cut.
Is protected against short circuit due to contact with the insulators 83a, 83b and the strap 85.

[0004]

In the above prior art,
For the protection work of winding the insulating sheet 86 and winding the adhesive tape 87, a direct construction method in which the worker directly wears the work glove having electrical insulation such as rubber and performs the work directly is often used. However, the insulating sheet 86 at a high place
And the winding operation of the adhesive tape 87 are troublesome, and the working efficiency is poor. Further, although indirect construction method using a manipulator or a gripper called an insulating Yatco may be used instead of the direct construction method,
Although the safety is improved as compared with the direct construction method, the work efficiency is further reduced, and the protection work of the insulators 83a and 83b and the strap 85 cannot be performed quickly. As described above, in both the direct method and the indirect method, it is desired to improve the efficiency of the protection work for live-line work.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a porcelain insulator cover and a method of manufacturing the same, which can improve the efficiency of protection work of the porcelain insulator by either the direct method or the indirect method. is there.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a cylindrical cover body made of an electrically insulating synthetic resin and divided in a circumferential direction, and an electrically insulating synthetic resin, which is provided at both circumferential ends of the cover body. An engagement portion having two engagement pieces that are connected to project radially outward, resiliently abut each other, and each free end most separated from the cover main body is expanded in a direction away from each other; And a grip portion made of an electrically insulating synthetic resin and protruding radially outward from an intermediate portion between both end portions in the circumferential direction of the cover main body. According to the present invention, the two engaging pieces formed continuously with the circumferential both ends of the cover main body have reciprocally elastic contact with each other and have free ends that are expanded in directions away from each other. So
By pushing the cover body into the traction insulator with the traction insulator disposed between the free ends of the engagement pieces, the engagement pieces are guided in the direction away from each other along the surface of the traction insulator. As a result, the cover body is pushed open, and the retaining insulator is accommodated in the cover body. Immediately thereafter, the two engagement pieces return to the state of being elastically contacted by the elastic restoring force of the cover body. Since the cover body, the engaging portion, and the gripping portion of the porcelain insulator are made of an electrically insulating synthetic resin, the protection operation of the porcelain insulator can be easily performed by attaching the porcelain insulator cover to the porcelain insulator as described above. This can improve the efficiency of the protective work. The insulator cover attached to the insulator is securely held even if an article such as a tool comes into contact or receives wind pressure, and can be prevented from falling off. In addition, since the grip portion is formed so as to protrude radially outward from an intermediate portion between both ends in the circumferential direction of the cover main body, when the cover is attached to the insulator by a direct method, for example, a work having electrical insulation properties is required. The gripper is directly gripped by the hand of the worker wearing the gloves, and the cover body is pushed into the insulator while the insulator is placed between the two engagement pieces. It can be attached to the porcelain insulator. When the cover is attached to the insulator by the indirect construction method, the grasping portion is grasped by a grasping tool or a robot manipulator, which is called an insulation cap, and the suspension insulator is arranged between the two engaging pieces as in the case of the direct construction method. In this state, the cover main body is pushed into the porcelain insulator, and the porcelain insulator cover can be quickly mounted on the porcelain insulator by a simple operation. As described above, the efficiency of the protection work can be improved by either the direct method or the indirect method as compared with the above-described conventional technology.

[0007] The electrically insulating synthetic resin constituting the insulator cover of the present invention is made of polyethylene, polypropylene, or the like.
And a mixture of polyethylene and polypropylene. According to the present invention, when the insulator cover is made of polyethylene, the polyethylene has good properties such as fluidity during molding and thermal stability, which are well-known properties in addition to electrical insulation and flexibility. By utilizing the advantageous properties in terms of manufacturing, for example, it is possible to manufacture the retaining insulator cover with high precision by faithfully conforming to a mold by, for example, blow molding. In addition, since polyethylene has impact resistance, it is possible to prevent the damage insulator cover from being damaged by an impact force caused by dropping or contact with another article such as a utility pole. In addition, the insulator cover is prevented from being damaged by the impact force due to contact with tools, etc., so that the insulator with the insulator cover attached can be protected from mechanical external force due to contact with tools during construction. . Furthermore, because polyethylene has weather resistance, the insulator cover can withstand the temperature difference between daytime and nighttime, the temperature difference between summertime and wintertime, the difference in geographical temperature, and the environment such as rainwater and snow adhesion. It is durable and can be used repeatedly over a long period of time. Moreover, since such polyethylene is a general-purpose synthetic resin, it is easily and commercially available at low cost,
The insulator cover can be manufactured at low cost. When the retaining insulator cover is made of polypropylene, for example, a blow-molding property, which is a well-known property other than electrical insulation and flexibility, that is good moldability, is used as properties of the polypropylene. By molding, the garment insulator cover can be manufactured with high precision by faithfully conforming to the mold. Further, since polypropylene has an excellent hinge effect, the polypropylene has durability against repeated bending stress generated when attaching and detaching the insulator cover to and from the insulator, and can prevent fatigue rupture of the cover body due to attachment and detachment work. Furthermore, since polypropylene has heat resistance, it is possible to prevent thermal deformation of the insulation cover by sunlight. Furthermore, since the polypropylene has impact resistance, it is possible to prevent the landing insulator cover from being damaged by an impact force caused by dropping or contact with another article such as a telephone pole. Furthermore, since the traction insulator cover is prevented from being damaged by the impact force due to contact with a tool, etc., the traction insulator with the garment insulator attached can be protected from mechanical external force due to contact with a tool or the like during construction. . Moreover, since such a polypropylene is a general-purpose synthetic resin, it can be obtained commercially easily and inexpensively, and a production insulator cover can be manufactured at low cost. When made of a material also called polyethylene propylene, which is a mixture of polyethylene and polypropylene, the impact weakness of polypropylene at low temperatures can be compensated by polyethylene, and the impact resistance and weather resistance combining these properties of polyethylene and polypropylene A good insulator cover can be obtained.

[0008] The method for manufacturing a retaining insulator cover according to the present invention comprises the steps of: forming a hollow cylindrical portion whose longitudinal ends are closed by an electrically insulating synthetic resin and divided in the circumferential direction; A hollow bulge protruding radially outward from the portion and extending linearly in the longitudinal direction of the cylindrical portion; and a grip protruding radially outward from the cylindrical portion at a position different from the bulge in the circumferential direction. Forming a molded body having a cylindrical portion and a bulging portion of the molded body, and cutting off a distal end portion of the bulging portion that is farthest radially outward from the cylindrical portion of the bulging portion. It is characterized by. According to the present invention, a formed body having a hollow cylindrical portion, a hollow bulging portion, and a grip portion is formed. This molded body can be easily formed integrally by, for example, blow molding. Such a molded body thermally shrinks due to a decrease in temperature after molding, so that an internal stress is generated so as to reduce the diameter of the cylindrical portion, thereby generating a force at which both ends in the circumferential direction are close to each other. Both ends in the circumferential direction of the cylindrical portion which are to approach each other by such a force for reducing the diameter are supported by the distal end portion and both ends in the longitudinal direction of the bulging portion, and the both ends in the circumferential direction are close to each other. Is blocked. By cutting off the both ends in the longitudinal direction of the molded body in this state and the distal end of the bulging portion, the force that prevented the displacement of the both ends in the circumferential direction in the direction approaching each other is released. The two formed engaging pieces resiliently abut each other. In this way, both ends in the circumferential direction can be resiliently brought into contact with each other in a direction approaching each other at the same time as the excision without separate processing, and the grip portion is also integrally formed with the cylindrical portion during molding. Therefore, the insulator cover can be obtained by a simple manufacturing process.

[0009]

FIG. 1 shows an embodiment of the present invention, in which a porcelain insulator cover 10 is attached to porcelain insulators 3a and 3b (hereinafter, referred to as "capacitors").
FIG. 2 is a perspective view showing a state of being attached to a strap 5 and a “insulator 3” or “insulator 3”. FIG. 2 is a front view of the insulator cover 10 shown in FIG. FIG. 2 is a side view of the retaining insulator cover 10. Insulation insulator cover (hereinafter sometimes abbreviated as "cover")
Reference numeral 10 is attached to the insulating insulator 3 in advance when an operator who is mounted on a bucket of a crane truck for aerial work (not shown) performs live-line work such as edge cutting and edge connection near the power pole 1. The cover 10 is made of a mixture of polyethylene and polypropylene, which are synthetic resins having flexibility and electrical insulation, and is integrally formed with a cover body 11, an engaging portion 12, and a grip portion 13.

The cover main body 11 is divided at one portion in the circumferential direction between both ends in the axial direction, and has a substantially cylindrical shape having a substantially C-shaped cross section at right angles to the axis. , The insulators may be abbreviated as "insulators")
The length in the longitudinal direction is larger than the outer diameter of each of the insulators 3a and 3b, and the length in the longitudinal direction is larger than the length in the longitudinal direction that can cover all the insulators 3a and 3b to be mounted and a part of the strap 5 connected to the insulator 3b. Are also formed large. The cover body 11 has circumferential end portions 14a, 14a with respect to its axis 11a.
a rib 26 protruding radially outward of the cover main body 11 from the central portion and extending in the axial direction at a central portion between both ends in the circumferential direction that is axially symmetric, and a bulge radially inward of the cover main body 11 As a result, the protrusions 27 extending in the axial direction are integrally formed. With the ribs 26 and the ridges 27, the cover main body 11 is opened in the direction in which the circumferential ends 14a, 14b are separated from each other, as will be described later, and from the opened state, the circumferential ends 14a, 14b are separated from each other. , Which is reinforced against the repetitive stress generated in the central portion by the opening / closing operation at the time of attachment / detachment.

The engaging portion 12 protrudes outward in the radial direction of the cover main body 11, extends linearly between both ends in the axial direction, and is formed integrally with one end 14a of the cover main body 11 in the circumferential direction. Engagement piece 15a and female engagement piece 1 formed integrally with the other circumferential end 14b of cover body 11
5b. The male engagement piece 15a is
With respect to an imaginary plane 21 including an axis 11a of the gripping portion 13 and a center portion in the thickness direction (left-right direction in FIG. 3) of the grip portion 13, a convex portion bent in an L-shape that is convex on one side in the circumferential direction (right side in FIG. 3). 16a is formed integrally with one end 14a of the cover body 11 in the circumferential direction, and the convex body 16a is
1 has a flat guide portion 18a extending radially outward and extending to the other side in the circumferential direction at an angle θ ₂ = 45 ° with respect to the virtual plane 21.

The female engagement piece 15 b is
A concave portion 16b bent in an L-shape that protrudes toward the one side in the circumferential direction is formed integrally with the other end portion 14b in the circumferential direction of the cover body 11, and the concave portion 16b is formed in the radial direction of the cover body 11 in the radial direction. Connected to the outside, the virtual plane 21
At the point of intersection with the male engaging piece 15a, and at an angle θ ₁ = 4 with respect to the virtual plane 21.
A flat guide portion 18b extending at 5 degrees. Free ends 19a and 19b are formed at one end of each of the guides 18a and 18b farthest from the cover main body 11, respectively. By bending each of the engagement pieces 15a and 15b as described above, both ends 14a and 14b in the circumferential direction are formed.
The creepage distance between each of the free ends 19a and 19b is
Since a and 15b are longer than those formed in a straight line, the surface insulation resistance over the creepage distance can be increased.

In the natural state, the above-mentioned convex portion 16a is formed into a concave portion 16b by an elastic recovery force acting in a direction in which both circumferential end portions 14a, 14b of the cover main body 11 approach each other.
And is abutting elastically. In this state, each of the guide portions 18a and 18b forms an angle θ ₁ + θ ₂ = 90 degrees, and expands in a direction away from each other as going outward in the radial direction.

When the cover 10 is mounted on the insulator 3, the free ends 19a and 19b are brought into contact with the outer peripheral surface of the insulator 3, and the cover 10 is pushed in a direction in which the cover body 11 and the insulator 3 come close to each other. By inserting the insulator 3, the free ends 19a,
19b, between the guide portions 18a and 18b, between the convex portion 16a and the concave portion 16b, and between the circumferential end portions 14a and 14b while being pushed and opened in a direction away from each other, and the internal space of the cover body 11 Fit inside. Insulator 3 is cover body 1
Immediately after the cover 10 is fitted in the cover 1, the cover 10 enters the natural state due to the elastic recovery force of the cover body 11.

FIG. 4 is an enlarged cross-sectional view of the retaining insulator cover 10 as viewed from the section line IV-IV in FIG. Gripper 13
Is configured to include a base portion 28, a ridge 29 for preventing slip, and a sheet 30 for preventing slip. The base 28 extends from substantially the center between the two ends in the longitudinal direction on the rib 26, from the rib 26.
It is formed in a plate shape protruding more radially outward. The anti-slip projections 29 are integrally formed on both surfaces in the thickness direction of the base 28. The anti-slip sheet 30 is made of, for example, hard rubber, and is fixed to a region surrounded by the anti-slip ridges 29 on both surfaces in the thickness direction of the base 28 with an adhesive or the like.

The gripping portion 13 formed as described above is used as a gripper or a robot manipulator (hereinafter, the gripper and the robot manipulator may be collectively abbreviated as "tool for indirect construction method") or an electrical insulator. Since the cover 10 can be reliably supported by the direct construction method in which the worker wearing the work gloves having the property is directly gripped with the hand, the cover 10 is attached to the insulator 3a,
The cover 10 is prevented from falling off when the cover 10 is mounted on the cover 3b.

FIGS. 5 (1) to 5 (4) are simplified side views showing the mounting procedure of the insulator cover 10. As shown in FIGS. Indirect method tool, for example, a gripper 8 called an insulation cap
The procedure for attaching the cover 10 of the present embodiment to the insulator 3 when a worker generally works below the cover 10 will be described. FIG. 5A illustrates a state in which an operator (not shown) uses the gripper 8 to grip the cover 13 of the cover 10.
Is a side view showing a state in which the cover 10 is moved so that the outer peripheral surface of the insulator 3 is gripped and the free ends 19a, 19b (see FIG. 3) of the engagement pieces 15a, 15b are brought into contact with the outer peripheral surface of the insulator 3. It is.

The operator selects the cover 10 having an inner diameter larger than the outer diameter of the insulator 3 to be mounted and an axial length longer than the axial length covering a part of the insulator 3 and the strap. An area of the grip portion 13 of the cover 10 to which the anti-slip sheet 30 (see FIG. 4) is adhered is gripped by gripping claws 9 provided on the gripping tool 8. As a result, the cover 10 is securely fixed to the gripper 8, and the cover 10 can be prevented from falling off during the mounting operation.

Next, the cover 10 is moved by operating the gripper 8 so that the outer peripheral surface of the insulator 3 comes into contact with the free ends 19a and 19b (see FIG. 3).
By pressing the grip portion 13 in a direction in which the engaging pieces 15a and 1 are close to each other, as shown in FIG.
5b is pushed open in a direction away from each other along the outer peripheral surface of the insulator 3, and the insulator 3 passes between the engagement pieces 15a, 15b, and as shown in FIG. It fits inside the internal space. As described above, the insulator 3 is formed of the cover body 11.
Immediately after the engagement pieces 15a and 15b are fitted inside, the engagement pieces 15a and 15b resiliently contact each other due to the elastic restoring force of the cover body 11, and the gap between the engagement pieces 15a and 15b disappears.

In this manner, the worker grasps the holding portion 13 and pushes the insulator 3 so as to pass between the engagement pieces 15a and 15b.
Can be attached to Further, the cover 10 mounted on the insulator 3 is rotated about half a turn using the gripping tool 8 so that the gripping portion 13 is located upward and the engaging portion 12 is positioned downward as shown in FIG. With each engagement piece 15a, 1
5b is disposed at a position farthest from the contact portion between the insulator 3 and the cover 10, and prevents the cover 10 from easily coming off due to the action of wind pressure on the cover 10 or the action of an external force due to the contact of an article. It is. The insulator 3 to which the cover 10 is attached in this way is protected from a short circuit caused by contact with the gripper 8 charged by touching the distribution line 3, for example. In addition, cover 1
The detachment procedure of “0” is the reverse of the above-described attachment procedure. Even in this detaching operation, the operator can remove the cover 10 from the insulator 3 by passing the insulator 3 between the engagement pieces 15a and 15b by a simple operation of pulling the grip portion 13. Here, the worker uses the gripper 8, but the worker may perform the attaching / detaching operation using a robot manipulator instead of the gripper 8, or directly by a human hand.

As described above, since the protection work of the insulator 3 can be easily performed by either the direct method or the indirect method using the tool for the indirect method, the efficiency of the operation can be improved.

FIG. 6 shows a power pole 31 on which three distribution lines having different phases are stretched.
FIG. 7 is a simplified front view showing the mounting state of a, 10b, and 10c, and FIG. 7 is a plan view seen from above in FIG. On the electric pole 31, two arm bars 32, 33 are respectively arranged in parallel along the longitudinal direction. One end 3 in the longitudinal direction of the arm 32
2a (the left side in FIGS. 6 and 7), one end of a metal strap 34a is fixed by means such as a bolt or a nut, and a first insulator 35a is fixed to the other end of the strap 34a. The insulator 35a is connected to a second insulator 36a which is locked by winding a distribution line 37a or the like.

The other end 32c of the arm 32 in the longitudinal direction (the right side in FIGS. 6 and 7) is also used.
a, the strap 34c, the first insulator 35c, the second
An insulator 36c and a distribution line 37c are provided. A metal U-strap 40 is locked to a central portion 32b between both ends in the longitudinal direction of the arm member 32. One end of the strap 34b is fixed to the U-strap 40 by means such as a bolt or a nut. At the other end, a first insulator 35b, a second insulator 36b, and a power distribution line 37b are provided similarly to the straps 34a and 34c. The arm 33 described above is attached to both ends 33 a and 33 c in the longitudinal direction of the arm 33.
Each of the straps 34a and 34c and each of the first insulators 35
a, 35c, each second insulator 36a, 36c, each distribution line 38
a, 38c are respectively provided.

The center portion 33b between both ends in the longitudinal direction of the arm 33 is also the same as the center portion 32a.
0, strap 34b, first insulator 35b, second insulator 36
b, distribution line 38b is provided. Wire 39a for edging
Are longitudinal ends 32a, 33 of the arms 32, 33, respectively.
a fixed to each pin insulator 41a, 42a
The distribution lines 37a and 38a are electrically connected.
The same applies to the electric wires 39b and 39c for edging.

When a worker performs hot-line work near the utility pole 31, each insulator 35 connected to the distribution line 37a is required.
a, 36a and each insulator 35 connected to the distribution line 38a
Attachment insulator covers 10a each having an outer surface painted red with, for example, an insulating paint or the like are attached to a and 36a, respectively. Further, each insulator 35b connected to the distribution line 37b,
36b and each insulator 35b connected to the distribution line 38b,
At 36b, a cover 1 for a porcelain insulator whose outer surface is painted blue
0b is attached. Further, the insulator 35c, 36c connected to the distribution line 37c and the insulator 35c, 36c connected to the distribution line 38c are fitted with a stationary insulator cover 10c whose outer surface is painted white. Thereby, each insulator 35
a-35c, 36a-36c and strap 34a-
The holding tool 34c is charged by contacting any one of the edging wires 39a to 39c,
It is protected from a short circuit due to contact with the gripper 8 in contact with the electric wires 39a to 39c or the cut electric wires 39a to 39c.

Further, for example, a distribution line 37a and a distribution line 38
c are electrically connected by the edging wire 39a,
In the case where the distribution line 37c and the distribution line 38a are electrically connected by the edging line 39c, the insulators 35a and 36a connected to the distribution line 37a and the insulators connected to the distribution line 38c. 35c and 36c are fitted with a retaining insulator cover 10a whose outer surface is painted red.
Insulators 35c, 36c connected to 7c and distribution line 3
The insulator insulator 10c whose outer surface is painted white is attached to each of the insulators 35a and 36a connected to the insulator 8a. By attaching a cover painted with the same color to each insulator that locks the distribution line electrically connected in this way,
The likelihood that workers will mistake the distribution lines that are out of phase,
Hot wire construction can be performed more safely. In addition,
Since the worker can easily confirm the position of the insulator at night by applying the fluorescent paint having electrical insulation, night work can be performed more safely. The insulating paint may be applied to a part of the outer surface of the traction insulator cover, for example, in a strip shape, or a colored tape having electrical insulation may be applied instead of the insulating paint.

Each insulator 35 fixed to the strap 34b fixed to the U strap 40 as described above.
As the cover 10b attached to the cover b, 36b, a cover having a length L1 shown in FIG. 7 that is longer than the other covers 10a, 10c in the longitudinal direction is selected. Thereby, a part of the U-strap 40 is connected to, for example, the edging wires 39a to 39c.
Can prevent a short circuit accident caused by contact of a charged gripping tool or the like by contacting any one of them.

FIG. 8 is a simplified perspective view of the hollow intermediate molded article 45 for explaining the procedure for manufacturing the cover 10 shown in FIGS. 1 to 5 by blow molding. The hollow intermediate molded article 45 has a hollow cylindrical portion 47 in which both ends 20a and 20b in the longitudinal direction are closed and one portion in the circumferential direction is divided between both ends in the longitudinal direction. A bulging portion 48a that protrudes radially outward from both end portions 14a and 14b (see FIG. 3) and extends in a straight line in the longitudinal direction of the cylindrical portion 47 and includes the engaging pieces 15a and 15b;
In order to prevent the engaging pieces 15a and 15b from abutting each other with a gap, the engaging piece tip portions 19a and 1
9b, and a distal end portion 48b integrally formed therebetween.

The intermediate molded article 45 can be easily obtained by blow molding using, for example, a mixture of polyethylene and polypropylene as a molding material. In the blow molding, the intermediate molded product 45 warmed by a mold at about 50 to 70 ° C. is cooled at a room temperature (about 20 ° C.). Since a mixture of polyethylene and polypropylene is excellent in moldability, a molded product faithful to a mold can be obtained. This is the same when polyethylene or polypropylene is used as a molding material. End walls 46a, 46b at both ends 20a, 20b in the longitudinal direction of the sufficiently cooled intermediate molded article 45
By cutting off the distal end portion 48b farthest radially outward from the cylindrical portion 47 of the bulging portion 48a,
The above cover 10 is formed. In the present embodiment, blow molding is used, but injection molding or extrusion molding may be used.

For example, after being molded at a high mold temperature of about 60 ° C., a cooled object, particularly a mixture of polyethylene and polypropylene, generates a shrinking force that tends to reduce the volume after the molding is completed. As a result, the hollow cylindrical portion 47 of the intermediate molded product 45 attempts to reduce its volume. At this time, the contraction force acting in the circumferential direction of the bottomed cylindrical portion 47 is generated so as to reduce the diameter, so that each of the circumferential end portions 14 is formed.
a and 14b try to approach each other. The distal end portion 48b and the both end portions 46 which resist such a contraction force.
a, 46b is cut off, so that each engagement piece 15a,
15b can resiliently contact. Although this is the same in the intermediate molded product molded only with polyethylene or polypropylene, when comparing the cover 10 formed with the above three types of molding materials,
The engagement pieces 15a, 15 are not required when the cover 10 made of polypropylene alone is made of a material of polyethylene alone or a mixture of polyethylene and polypropylene.
b can be more reliably resiliently brought into contact with each other, and there is no gap between the locking pieces 15a and 15b.

In this way, since the circumferential end portions 14a and 14b can be reliably brought into contact with the cut at the same time as the cutting operation, the retaining insulator cover 1 having a high shape accuracy can be obtained by a simple manufacturing process.
0 can be obtained.

In this embodiment, since a material called polyethylene propylene in which polyethylene and polypropylene are mixed is used as the molding material, the impact weakness of polypropylene at low temperature can be compensated by polyethylene. It is possible to obtain the insulation insulator cover 10 having both characteristics of polypropylene and good impact resistance and weather resistance.

In another embodiment of the present invention, the molding material may be polyethylene. In this case, the polyethylene has various characteristics other than electric insulation and flexibility, which are well-known characteristics. Utilizing the advantageous properties in terms of production, such as good fluidity and thermal stability, the porcelain insulator cover 10 can be manufactured with high precision by, for example, blow molding so as to faithfully conform to a mold. Also, since polyethylene has impact resistance, the insulator 10
Can be prevented from being damaged by an impact force caused by dropping during mounting or contact with another article such as a telephone pole. In addition, since the insulator cover 10 is prevented from being damaged by impact force due to contact with a tool or the like, the insulator 3 to which the insulator cover 10 is attached is protected from mechanical external force due to contact with a tool or the like during construction. can do. Furthermore, since polyethylene has weather resistance, the insulator cover 10 sufficiently withstands the environment such as temperature difference between daytime and nighttime, temperature difference between summertime and wintertime, difference in geographical temperature, and adhesion of rainwater and snow. It is durable and can be used repeatedly over a long period of time. Moreover, such polyethylene is
Since it is a general-purpose synthetic resin, it is commercially available easily and inexpensively, and the insulator cover 10 can be manufactured at low cost.

In still another embodiment of the present invention, the molding material may be polypropylene. In this case, the properties of the polypropylene include molding properties that are well-known in addition to electrical insulation and flexibility. Utilizing the advantageous property in terms of manufacturing that the property is good, the traction insulator cover 10 can be manufactured with high precision by, for example, blow molding so as to faithfully conform to a mold. In addition, since polypropylene has an excellent hinge effect, it has durability against repeated bending stress generated when attaching and detaching the insulator cover 10 to and from the insulator 3, and prevents fatigue rupture of the cover body 11 due to attachment and detachment work. Can be. Furthermore, since polypropylene has heat resistance, thermal deformation of the insulator cover 10 due to sunlight can be prevented. Furthermore, since polypropylene has impact resistance, the insulator cover 10 is prevented from being damaged by a drop or an impact force caused by contact with another article such as a telephone pole. In addition, since the insulator cover 10 is prevented from being damaged by impact force due to contact with a tool or the like, the insulator 3 to which the insulator cover 10 is attached is protected from mechanical external force due to contact with a tool or the like during construction. can do. Moreover, since such polypropylene is a general-purpose synthetic resin, it can be obtained commercially easily and inexpensively, and the insulator cover 10 can be manufactured at low cost.

FIG. 9 is a simplified perspective view showing the structure of a cover 50 according to another embodiment of the present invention. Portions corresponding to the above-described embodiments are denoted by the same reference numerals, and description thereof will be omitted. The cover 50 is configured to include the cover main body 11, the engaging portion 12, the grip portion 51, the fall prevention ring 52, and the connecting cord 53. Fall prevention ring 52
Is made of an electrically insulating material such as acrylic resin, and is formed in an annular shape having an inner diameter through which a hand of a worker wearing the gripper 8 or working gloves can be inserted. The connecting string 53 is formed of a flexible and electrically insulating material such as nylon. The grip 51 is provided with a connecting cord 5 at one end of the base 28 shown in FIGS.
It comprises a base 55 provided with an insertion hole 54 through which the 3 is inserted, the anti-slip ridge 29, and the anti-slip sheet 30.
The fall prevention ring 52 and the base 55 are gently connected to each other by the connection cord 53 inserted through the insertion hole 54.

When removing the cover 50 from each of the insulators 3a and 3b, generally, when the worker works under the cover 50, the fall prevention ring 52 is gripped by the gripper 8 and the grip portion 51 is moved. The cover 50 is pulled to be close to the worker, and the cover 50 is rotated in the circumferential direction. Next, the gripper 8
The gripping portion 51 is held by the gripping claws 9 while the arm is inserted through the fall prevention ring 52. In this state, each of the engagement pieces 15a and 15b is disposed above, and the gripper 51 is disposed below. When the worker faces upward from below and pulls the gripper 8 downward, the cover is opened. The respective engaging pieces 15a, 15b of 50 are pushed apart from each other and pushed open by the insulators 3a, 3b, and the cover 50 is separated from the insulators 3a, 3b.
Can be smoothly separated from the vehicle. Also, when performing the attaching / detaching work of the cover 50, by inserting the arm of the gripper 8 through the fall prevention ring 52, even if the gripping state of the gripper 51 by the gripper claw 9 is released due to some trouble,
The cover 50 can be prevented from falling to the ground. Also, when the robot manipulator is used instead of the mounting tool 8 or when the worker directly performs the attaching / detaching work, the fall of the cover 50 is similarly prevented.

FIG. 10 is a front view showing a simplified structure of a retaining insulator cover 59 according to still another embodiment of the present invention. Note that the same reference numerals are given to portions corresponding to the above-described embodiment, and description thereof will be omitted. The cover 59
Includes a cover main body 11, a grip portion 13, and an engagement portion 60.
The engaging portion 60 protrudes outward in the radial direction of the cover main body 11 and extends between both ends in the axial direction.
And a female engaging piece 64a, a convex portion 16b, a concave portion 16a, and guide portions 61a and 61b. Inclined portions 63 are formed at both ends in the longitudinal direction of the engagement pieces 64a, 64b so as to be inclined toward the cover body 11 toward one end in the longitudinal direction.

In the work of attaching the cover 59, one of the inclined surfaces 63 of the cover 59 is brought into contact with the outer peripheral surface of the insulator 3b to be attached, and the cover body 11 is attached to the insulator 3b.
b, one end of the engaging portion 60 is opened, and by further pushing, the cover body 11 is sequentially guided from one end to the other end of the engaging portion 60 along the insulators 3a, 3b. Further, the insulators 3a and 3b are accommodated in the inner space of the cover main body 11 by being further pushed in.
0 abuts elastically. The subsequent mounting procedure is the same as the mounting procedure shown in FIG. The mounting procedure of the cover 59 is different from the mounting procedure shown in FIG. 5 in that the inclined portion 63 has the guide portions 18a and 18b in the area where the cover should contact the insulators 3a and 3b (see FIGS. 1 to 5). Smaller, so that the mounting operation can be facilitated. In addition, since the engaging portions 64a and 64b can be smoothly pushed in while being sequentially opened from either one of both ends in the longitudinal direction, the force required to push the cover main body 11 at the time of mounting work is reduced as shown in FIGS. 5 can be reduced as compared with the embodiment shown in FIG.

[0039]

As described above, according to the present invention, the work of attaching and detaching the porcelain insulator cover for protecting the porcelain insulator can be easily performed, so that the work efficiency of the hot-line construction can be greatly improved. .

Further, according to the present invention, when the electrically insulating synthetic resin is made of polyethylene, the electrical insulation, impact resistance,
In addition, it is possible to manufacture a weather insulator having weather resistance with high accuracy and low cost. In addition, when the electrically insulating synthetic resin is made of polypropylene, it is possible to manufacture the insulating insulator cover having electrical insulation, durability against repeated bending stress, and heat resistance with high precision and at low cost. In addition, if the electrically insulating synthetic resin consists of a mixture of polyethylene and polypropylene, the impact weakness of polypropylene can be compensated by polyethylene, with both the properties of impact resistance and weather resistance of both polyethylene and polypropylene. A good insulator cover can be obtained.

Further, according to the present invention, the porcelain insulator cover can be obtained by a simple manufacturing process, so that the productivity of the porcelain insulator cover is improved.

[Brief description of the drawings]

FIG. 1 is an illustration of a traction insulator cover 1 according to an embodiment of the present invention.
FIG. 5 is a perspective view showing a state in which 0 is attached to each of the retaining insulators 3a, 3b and the strap 5.

FIG. 2 is a front view of the insulator cover 10 shown in FIG.

FIG. 3 is a side view of the retaining insulator cover shown in FIG.

FIG. 4 is a sectional view taken along line IV-I of FIG.
It is sectional drawing seen from V.

FIG. 5 is a simplified side view showing a procedure for attaching and detaching the retaining insulator cover 10.

FIG. 6 is an illustration of a pole insulator 31 on which three electric wires having different phases and voltages are stretched.
It is the simplified front view which shows the state which attaches b and 10c.

FIG. 7 is a plan view of the electric pole 31 of FIG. 6 as viewed from above.

FIG. 8 shows a hollow intermediate molded product 4 for explaining a procedure for manufacturing the cover 10 shown in FIGS. 1 to 5 by blow molding.
5 is a simplified perspective view of FIG.

FIG. 9 is a perspective view showing a simplified configuration of a traction insulator cover 50 according to another embodiment of the present invention.

FIG. 10 is a simplified front view showing a configuration of a porcelain insulator cover 59 according to still another embodiment of the present invention.

FIG. 11 is a perspective view showing a protection state of the porcelain insulators 3a and 3b using a typical conventional insulating sheet 6;

[Explanation of symbols]

 3a, 3b Insulator 6, 34a-34c Strap 10, 50, 59 Insulator cover 11 Cover body 12 Engagement part 13 Grip part

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Katsuharu Maekawa, Inventor, Katsuharu Maekawa 4-5-21, Nishi-ku, Nishi-ku, Osaka, Japan (72) Inventor Masatoshi Nishiguchi 4-5-21, Nishi-ku, Nishi-ku, Osaka, Osaka Inside the corporation

Claims (3)

[Claims] 1. A cover body made of an electrically insulating synthetic resin and divided in the circumferential direction, and a cylindrical cover body made of an electrically insulating synthetic resin and connected to both circumferential ends of the cover body to protrude outward in the radial direction. An engaging portion having two engaging pieces which resiliently abut each other and each of the free ends farthest from the cover body expands in a direction away from each other; and an electrically insulating synthetic resin. And a grip portion protruding radially outward from an intermediate portion between both end portions in the circumferential direction of the cover main body. 2. The electrically insulating synthetic resin is polyethylene,
2. The insulator cover according to claim 1, wherein the cover is made of one of polypropylene and a mixture of polyethylene and polypropylene. 3. A hollow cylindrical part whose both ends in the longitudinal direction are closed by an electrically insulating synthetic resin and is divided in the circumferential direction, and said hollow cylindrical part protrudes radially outward from both ends in the circumferential direction of said cylindrical part. Forming a molded body having a hollow bulging portion extending in a straight line in the longitudinal direction of the cylindrical portion, and a grip portion projecting radially outward at a position different from the bulging portion in the circumferential direction from the cylindrical portion, Both ends in the longitudinal direction of the cylindrical portion and the bulging portion of the molded body,
A method for manufacturing a traction insulator cover, comprising cutting off a tip of a bulging portion farthest radially outward from the cylindrical portion.