Installation tool and method of NXJ type tension clamp

Abstract

The present invention relates to an installation tool and method for an NXJ type tension clamp, and belongs to the technical field of power fittings and electrician tools. The installation tool comprises a core hook, an outer frame, an inner frame and a pull bolt. The wedge core of the tension clamp is hooked by the core hook, the tensioner is connected by the outer frame, and the pull ring of the clamp body is connected by the inner frame. The pull bolt is driven to rotate in the opposite direction, so that the wedge core moves relative to the clamp body to obtain a certain pre-tightening force, which is the same as the gripping force required in line operation; so that the gripping force of the tension clamp can meet the needs of line operation, avoid obvious slippage, prevent the outer skin from tearing and running, and ensure safety. In the pre-tightening operation, the wedge core and the insulated wire are driven to move backward synchronously without relative movement. The insulated wire in front of the tensioner remains in a relaxed state, which can avoid damaging the insulated wire and ensure safe operation. The pre-tightening operation only involves loosening the pull bolt, which saves operating energy, is convenient to operate, can slow down the pre-tightening process, avoids impact, and ensures safe operation.

Description

Technical Field

[0001] The invention relates to a tool and a method for installing a tension clamp, and belongs to the technical field of power hardware and electrician tools. Background Art

[0002] NXJ type tension clamp is a hardware fitting for overhead power distribution lines, used for laying overhead insulated conductors. Insulated conductors are made by extruding insulating materials such as cross-linked polyethylene and polyvinyl chloride onto the outer layer of aluminum, aluminum alloy or copper stranded wire, with an insulating sheath. Compared with NXL and NLL type tension clamps, the installation process of NXJ type tension clamps is convenient and efficient. It does not require the outer skin of the insulated conductor to be stripped, and does not require the collaboration of multiple people, and has been widely used. According to the provisions of the power industry standard DL / T765.3-2021 "Overhead Distribution Line Hardware Part 3: Overhead Insulated Wire Hardware Fittings for Rated Voltage 35kV and Below", the gripping force of the tension clamp should not be less than 65% of the calculated breaking force of the insulated conductor being gripped. However, in the gripping force test of the NXJ type tension clamp, it is often difficult to meet the standard requirements; in the operation practice of the NXJ type tension clamp, the conductor often falls off, causing accidents. Wang Yunhui, Yan Tao, Li Xue and others published an article in the Journal of Electrical Engineering in March 2021 titled "Analysis of the Causes of Failure of NXJ-type Strain Clamps Caused by Conductor Slippage and Structural Optimization" which states: According to the inspection report of some hardware in Yunnan Province in 2017, all unqualified products were NXJ-type strain clamps, and the reason was that the grip strength did not meet the standard; a survey on the use of overhead line strain clamps in a certain city in Yunnan found that the qualified NXJ-type strain clamps still had problems with loose and slipped insulated wires during use. Liu Guangzhong published an article in Electronic Production in February 2017 titled "Analysis of the Causes of Conductor Shedding of Wedge-type Insulated Strain Clamps on 10kV Lines" which states: Improper installation of the wedge core is one of the important reasons for the conductor shedding of the wedge-type insulated strain clamp; the investigation found that the installers did not have a full understanding of the scientific installation method of the wedge core, or lacked sufficient sense of responsibility; during acceptance, the bottom of the wedge core should be hit with a hammer to observe whether it moves.

[0003] The NXJ type tension clamp includes a wedge-shaped clamp body (also known as a wedge tube, main body or outer wedge) and a wedge core (also known as a wedge, clamp, inner wedge, core or wedge). It is not necessary to tighten the bolts during installation, so no special tools are used. The clamp body adopts a C-shaped opening structure with a wedge-shaped inner cavity; the wedge core includes two independent parts that cooperate with each other, with a wedge shape on the outer surface that cooperates with the inner cavity of the clamp body, and a groove on the inner surface, through which the insulated wire is accommodated. The groove of the wedge core fits the outer skin of the insulated wire and does not have a wedge shape; therefore, the wedge core is subjected to the lateral extrusion of the clamp body, generating a grip on the insulated wire and playing a role in transmitting force. The grip of the wedge core on the insulated wire depends on the friction between them, so it is larger than the friction coefficient between it and the clamp body. In the clamping state, the pulling force of the wire on the wedge core makes the wire clamp body generate sufficient clamping force on the wedge core through the wedge shape, and also makes the wedge core generate sufficient clamping force on the insulated wire, that is, gripping force, to ensure that the insulated wire will not slip off, and it will become tighter and tighter; the greater the pulling force, the greater the gripping force required.

[0004] During installation, the insulated wire needs to obtain sufficient gripping force first so that the tension clamp can withstand its tension, so it needs to be pre-tightened. The existing technology uses the impact of heavy objects to perform pre-tightening operations; in the specific construction process, it is common to use readily available wrenches, hammers, or hardware and other heavy objects to hit the wedge core for pre-tightening. In manual impact pre-tightening, human factors have a greater impact, and the obtained pre-tightening force is uncertain; after pre-tightening, when the grip of the tension clamp generates insufficient friction on the insulated wire to counteract its pulling force, it will cause obvious slippage or line deviation, affecting construction safety; it will also cause the relative slippage of the outer skin of the insulated wire to be large, easy to tear, and affect the safe operation of the distribution line. Especially in the hot summer, the high temperature weather causes the outer skin of the wedge core and the insulated wire to be soft and easy to deform, making it more prone to obvious slippage, outer skin tearing, and line deviation. The wire clamp body of the NXJ type tension clamp adopts a C-shaped opening structure with a wedge-shaped inner cavity; therefore, when the preload is too large, due to the self-locking effect of the wedge, the lateral pressing force of the wire clamp body on the wedge core is too large, resulting in excessive deformation of the wire clamp body and the wedge core, which is prone to plastic deformation and damage. In addition, the impact point, impact force size and direction of the manual impact preload operation are uncertain, which is easy to damage the wire clamp body, wedge core and insulated wire, affecting construction safety and operation safety.

[0005] In order to effectively prevent the wire from falling off and improve the grip, a variety of technical solutions have been proposed. The invention patent with application number 201110158750.8 discloses a quick self-locking aluminum alloy tension clamp, which includes a pre-tightening thrust tube; during installation, the pre-tightening thrust tube is installed, and then the pipe plug is installed and tightened with a hammer to fasten the wire and the clamp together to prevent the wire from falling off. The utility model patent with application number 201920759180.X discloses an anti-slip electrical hardware used in conjunction with the NXJ wedge-shaped insulated tension clamp, including a pair of clamping blocks, connecting bolts and nuts; the wire passes through the two clamping blocks, and the nuts are tightened so that the two clamping blocks clamp the wire to prevent the wire from slipping off. The utility model patent with application number 201521135830.1 discloses a wedge-shaped tension clamp, including a shell with a wedge-shaped cavity, a sandwich assembly and an elastic member; the elastic force of the elastic member increases the force of the sandwich assembly on the cable, thereby improving the locking performance; it saves tools and pre-tightening steps during installation, making installation convenient. In the installation of other wedge-shaped clamps, manual impact pre-tightening is also widely used. For example, the utility model patent with application number 201921616850.9 discloses a portable wedge sleeve clamp pre-tightening tool, including a columnar body and a striking head, and a wire groove is provided to make the clamp evenly stressed, and the wire is pre-installed and tightened to avoid damage to the clamp body.

[0006] When installing the NXJ type tension clamp, a tensioner is used to tighten the insulated wire; the tensioner is connected to a wire clamp (also known as a wire clamp) to clamp the insulated wire; the NXJ type tension clamp is provided with a pull ring on its clamp body to connect the hook of the tensioner. The invention patent with application number 201610888739.X discloses a tensioner with better adjustability, which can simultaneously hang two sets of auxiliary tensioners and selectively tighten, and can achieve coarse adjustment and fine adjustment. The utility model patent with application number 201620372755.9 discloses a double-hook tensioner for power construction, in which electricity is used instead of manpower in the tightening process, and the degree of tightening is controlled by a control device. The utility model patent with application number 201620699514.5 discloses a tensioner dedicated to insulated wires, including a wedge-shaped insulated tension clamp to protect the insulation layer and prevent slipping and loosening.

[0007] With the application and development of new generation information technologies such as the Internet of Things, cloud computing and artificial intelligence, the intelligence level of power grids is constantly improving; the development trend of "machines replacing people" is obvious, and robot inspection technology has been rapidly developed and applied. The existing installation technology of NXJ type tension clamps uses manual impact pre-tightening, and the pre-tightening force is uncertain, which is prone to obvious slippage, outer skin tearing and line running, affecting construction safety; it is also difficult to use robots for operation, which does not conform to the development trend of "machines replacing people" and needs further research and improvement. Summary of the invention

[0008] The purpose of the present invention is to provide an installation tool and method for an NXJ type tension clamp, which replaces the existing manual impact pre-tightening method, can obtain a certain pre-tightening force, so that its gripping force can meet the needs of line operation; avoid obvious slippage, put an end to outer skin tearing and line running, and ensure safety; easy to operate, suitable for robot operation. The orientation described in this specification is based on the NXJ type tension clamp in the installed state, the direction close to the pole tower is front, and the opposite direction is rear; the front and rear direction is longitudinal, and the direction perpendicular to the front and rear direction is transverse; other directions are deduced by analogy. Figure 1 In the figure, the left side is the front, and the other directions are analogous. The specific technical scheme of the present invention is as follows.

[0009] An installation tool for an NXJ type tension clamp is used to fix the insulated wire tightened by a tensioner to the installation process of the tension clamp; the tension clamp comprises a clamp body and a wedge core, the clamp body has a pull ring; the tensioner has a hook, and the pull ring or other hardware can be hung by the hook. The installation tool comprises a core hook 1, an outer frame 2, an inner frame 3 and a pull bolt 4, such as Figure 1 As shown, the wedge core of the tension clamp is hooked by the core hook 1, the hook of the tensioner is connected by the outer frame 2, the pull ring is connected by the inner frame 3, and the pull bolt 4 is driven by a wrench to rotate in the opposite direction, so that the wedge core moves relative to the clamp body, and a certain pre-tightening force is obtained, so that the gripping force of the tension clamp can meet the needs of line operation, avoid obvious slippage, prevent the outer skin from tearing and the line from running, and ensure safety. The pre-tightening force is the initial gripping force of the wedge core of the tension clamp on the insulated wire through the pre-tightening operation.

[0010] The core hook 1 is a longitudinal L-shaped hook-shaped curved plate, comprising a transversely erected hook plate 11 and a longitudinally flat pull plate 12. The wedge core is hooked by the hook plate 11, and the pull plate 12 is elastically hinged with the outer frame 2 to perform a pre-tightening operation. The hook plate 11 is a transversely erected plate-shaped structure with a front surface and a rear surface. It is fixedly connected to the pull plate 12 at the upper end and is bent downward relative to the pull plate 12 to present a hook shape, such as Figure 2As shown, the rear surface is in contact with and pressed against the front end of the wedge core to hook the wedge core and perform a pre-tightening operation. The hook plate 11 has a notch 15 at the bottom, through which the insulated wire passes to avoid interference when hooking the wedge core. The notch 15 passes through the hook plate 11 from front to back, extending from the middle of the hook plate 11 to the lower end, and forming an opening at the lower end; when the hook plate 11 moves from top to bottom to hook the wedge core, the insulated wire can be inserted through the opening, so that the insulated wire enters the notch 15 to avoid interference. The hook plate 11 is bent backward at the lower end to present a hook shape, so as to avoid accidental disengagement when hooking the wedge core for pre-tightening, thereby ensuring safe operation. The hook plate 11 has a flexible wear-resistant layer on the rear surface, through which the wear-resistant layer is in contact with and pressed against the end face of the front end of the wedge core to protect the front end of the wedge core, thereby preventing the wedge core from plastic deformation and fragmentation, thereby ensuring safety.

[0011] The pull plate 12 is a longitudinally flat straight plate with an upper surface and a lower surface. It is fixedly connected to the upper end of the hook plate 11 at the front end, so that the core hook 1 presents a longitudinal L-shaped hook-shaped curved plate. The pull plate 12 has a transverse pin hole 13 at the rear end. The pin shaft passes through the pin hole 13, so that the pull plate 12 is elastically hinged with the outer frame 2, and the pull plate 12 can rotate relative to the outer frame 2. The hook plate 11 can move up and down to hook the wedge core for pre-tightening. The front surface of the hook plate 11 and the upper surface of the pull plate 12 are both provided with reinforcing ribs 14 to improve the structural strength, avoid plastic deformation and damage during the pre-tightening operation during the installation process, and ensure safety.

[0012] The outer frame 2 is a longitudinal frame-shaped structure, including a left side plate, a right side plate and an upper connecting plate, accommodating the inner frame 3 and the pull bolt 4 at the front, bending downward at the rear to form a transverse vertical plate, with a plate hole 21 at the front end, an external viewing hole 22 at the front of the upper connecting plate, a longitudinal sleeve hole 23 and a sleeve 24 in the middle of the vertical plate, and the sleeve 24 is fixed by the sleeve hole 23, a longitudinal wire groove 25 is provided on the lower surface of the rear part, and a hook hole 26 is provided at the rear end, as shown in FIG. Figure 3 and Figure 4 As shown, the hook of the tensioner is hung through the hook hole 26, so that the outer frame 2 bears the tension of the insulated wire, causing the core hook 1 to generate a backward pulling force, so that the wedge core can obtain the tension of the insulated wire for pre-tightening.

[0013] The left side plate and the right side plate have the same structure, both are vertical curved plates, which are straight in the longitudinal direction and curved up and down. The upper edge at the front is fixedly connected to the upper connecting plate, so that the cross section of the outer frame 2 at the front presents an inverted U-shaped structure to accommodate the inner frame 3 and the pull bolt 4, so that the inner frame 3 can only move longitudinally and cannot rotate, and the pull bolt 4 can also drive the inner frame 3 to move longitudinally by rotation. The left side plate and the right side plate are both provided with plate holes 21 at the front end. The plate hole 21 is a transverse through hole, which passes through the pin shaft together with the pin hole 13 at the rear end of the core hook 1, so that the outer frame 2 is elastically hinged at the front end with the rear end of the core hook 1, so that the core hook 1 can obtain the tension of the insulated wire, generate a backward pulling force, and perform a pre-tightening operation. The pin shaft is inserted into the torsion spring to form an elastic hinge, so that the pull plate 12 is elastically hinged to the outer frame 2; the core hook 1 can rotate relative to the outer frame 2 to avoid interference; the core hook 1 can also rely on the elastic force of the torsion spring to overcome its gravity and maintain its relative position with the outer frame 2, simplifying the installation operation process and avoiding sagging and shaking of the core hook 1.

[0014] The upper connecting plate is a longitudinal flat plate at the front of the outer frame 2, and is fixedly connected to the upper edges of the left and right plates at the left and right edges, respectively, so that the outer frame 2 becomes one, presents a frame-shaped structure, and accommodates the inner frame 3 and the pull bolt 4. The upper connecting plate has an external viewing hole 22 at the front. The external viewing holes 22 are located in front of the vertical plate, are evenly distributed longitudinally on the upper connecting plate, and are through the upper and lower parts, so as to facilitate observation of the state and movement of the inner frame 3 and the pull bolt 4, and also reduce weight.

[0015] The upper connecting plate, the left side plate and the right side plate are all bent downward at the rear, so that the upper connecting plate forms the said vertical plate standing horizontally at the rear. The said vertical plate has a longitudinal through hole 23 in the middle, and the said sleeve 24 is clamped through the said sleeve 23, so that the said pull bolt 4 passes through the said sleeve 24 and is connected with the said inner frame 3, so as to improve the structural strength, avoid the wear of the said vertical plate and its sleeve 23, and improve the service life. The said sleeve 24 is a longitudinal cylindrical structure, with a longitudinal inner hole, and a circular convex edge at the rear end; it passes through the said sleeve 23 and has an interference fit with it; the front surface of the said convex edge is in contact with the rear surface of the said vertical plate, so that the said sleeve 24 is clamped in the said sleeve 23, and is fixed and supported. The inner hole of the said sleeve 24 is a smooth hole, which is in clearance fit with the said pull bolt 4, so that the said pull bolt 4 can move and rotate longitudinally relative to the said sleeve 24.

[0016] The upper connecting plate, the left side plate and the right side plate extend backward through the vertical plate, and the left side plate and the right side plate remain longitudinally straight at the lower side of the rear portion to form the longitudinal wire groove 25; the upper connecting plate gradually narrows backward, so that the left side plate and the right side plate gradually approach each other at the upper side of the rear portion, and are attached to each other at the upper side of the rear end to form a whole; and a hook hole 26 is provided at the upper side of the rear end that is attached to each other to form a whole, such as Figure 3 and Figure 4 The wire groove 25 is located on the lower surface of the rear part of the outer frame 2, with the opening facing downward, so as to accommodate the insulated wires and prevent the outer frame 2 from interfering with the insulated wires during installation. The hook hole 26 is a horizontal circular through hole for hanging the hook of the tensioner, so that the outer frame 2 bears the tension of the insulated wires and performs a pre-tightening operation.

[0017] The inner frame 3 is a longitudinal frame-shaped structure, located inside the outer frame 2, and includes a left curved plate, a right curved plate and an upper curved plate. The left curved plate, the right curved plate and the upper curved plate are bent to form an end plate at the rear end. The front end is provided with a transverse nail hole 31, the upper curved plate is provided with an inner viewing hole 32 that passes through from top to bottom, and the middle part of the end plate is provided with a longitudinal through hole 33 and a nut 34. Figure 5 As shown, a pin is passed through the nail hole 31 and the pull ring together, and is hung with the pull ring at the front end and cooperates with the pull bolt 4 through the nut 34 at the rear end to withstand the tension of the insulated wire, so that the pull ring withstands the backward pulling force. It can also drive the pull bolt 4 to rotate in the opposite direction, causing the outer frame 2 to move backward longitudinally, resulting in the core hook 1 generating a backward pulling force, so that the wedge core obtains the tension of the insulated wire and performs a pre-tightening operation.

[0018] The left curved plate and the right curved plate have the same structure, both of which include a longitudinally erected straight plate portion and a transverse curved portion 36. Both are fixedly connected to the upper curved plate at the upper edge of the straight plate portion to form an integral body, and both are transversely bent inward at the rear end of the straight plate portion to form the transverse curved portion 36. The upper curved plate includes a longitudinally straight flat plate portion and a downwardly bent portion 35. The left and right edges of the flat plate portion are respectively fixedly connected to the upper edges of the left curved plate and the right curved plate to form an integral body and present a frame-shaped structure, and the rear end of the flat plate portion is bent downward to form the downwardly bent portion 35. The downwardly bent portion 35 and the transverse curved portion 36 together constitute the end plate of the inner frame 3, as shown in FIG. Figure 5 As shown, the end plate has sufficient structural strength to withstand the tension of the insulated wire.

[0019] The left curved plate and the right curved plate both have a transverse nail hole 31 at the front end, and a pin passes through the nail hole 31 and the pull ring together, and is hung with the pull ring at the front end. Therefore, the nail hole 31 and the pin have a stop structure to prevent the pin from accidentally withdrawing from the nail hole 31 during the pre-tightening operation, thereby avoiding accidents. The inner viewing holes 32 are evenly distributed longitudinally on the flat plate portion of the upper curved plate, and penetrate up and down. The spacing between them is the same as the outer viewing holes 22 of the outer frame 2, so that when it is opposite to the outer viewing holes 22, the state and movement of the pull bolt 4 and the insulated wire can be observed, and the weight can also be reduced. The lower curved portion 35 of the upper curved plate has a longitudinal hole, and the transverse curved portions 36 of the left curved plate and the right curved plate both have arc-shaped notches; the longitudinal hole is aligned with the arc-shaped notch, and together constitutes the through hole 33, so that the through hole 33 is located in the middle of the end plate and penetrates longitudinally.

[0020] The nut 34 is a longitudinal cylindrical structure with a longitudinal threaded hole and a circular convex edge at the front end, which passes through the through hole 33 and is interference fit therewith; the rear surface of the convex edge is in contact with the front surface of the end plate, so that the nut 34 is fixed to the through hole 33 to obtain fixation and support. The threaded hole of the nut 34 has an internal thread, which cooperates with the pull bolt 4 through the internal thread, so that the pull bolt 4 rotates, and can drive the inner frame 3 to move longitudinally relative to the outer frame 2.

[0021] The pull bolt 4 includes a longitudinal screw and a head, which is subjected to tensile force. The front end of the screw is provided with a cotter pin 41 and a stop nut 42. The screw passes through the sleeve 24 of the outer frame 2 at the rear, so that the head is exposed from the outer frame 2 and is located behind the vertical plate of the outer frame 2, so that it is convenient to screw with a wrench for pre-tightening. The screw is a cylindrical structure with an external thread. The external thread cooperates with the internal thread of the nut 34 so that the pull bolt 4 can rotate and drive the nut 34 to move longitudinally relative to each other. The screw has a transverse through hole at the front end, and the cotter pin 41 passes through the through hole, so that the cotter pin 41 is fixedly installed at the front end of the screw to limit the position of the stop nut 42 to prevent it from falling off, and to prevent the pull bolt 4 from separating from the nut 34, resulting in accidental impact and falling off, thereby preventing accidents or loss of parts. The head is located at the rear end of the screw and is fixedly connected to the screw. The transverse dimension is larger than the diameter of the screw. The front surface is attached to and pressed against the rear surface of the convex edge of the sleeve 24, so that the pull bolt 4 can obtain the tension of the insulated wire through the outer frame 2 for pre-tightening. The head has a screwing structure, which can drive the pull bolt 4 to rotate. The stop nut 42 has a threaded inner hole, which cooperates with the front end of the screw through the threaded inner hole, and has a stop structure, which cooperates with the cotter pin 41 to stop and prevent rotation and falling off.

[0022] An installation method of an NXJ type tension clamp, using the installation tool, is used to fix the insulated wire to the installation process of the tension clamp, comprising the following steps:

[0023] The first step is to prepare installation tools: use a wrench to screw the head of the pull bolt 4, drive the pull bolt 4 to rotate forward, and drive the inner frame 3 to move backward relative to the outer frame 2;

[0024] Observe the relative position and movement of the inner frame 3 through the outer viewing hole 22 and the inner viewing hole 32;

[0025] When the rear surface of the end plate of the inner frame 3 reaches the front surface of the vertical plate of the outer frame 2 and the twisting resistance of the wrench increases significantly, the twisting is finished; at this time, the nut 34 is located at the rear end of the pull bolt 4;

[0026] The hook of the tensioner is hooked into the hook hole 26 to hook the installation tool to the tensioner.

[0027] The second step is to connect the installation tool: connect the tension clamp to the insulator and install it on the cross arm of the tower;

[0028] Clamping the insulated wire using the wire tightener;

[0029] Pull the installation tool hung on the tensioner so that the pull ring of the tension clamp is located between the left curved plate and the right curved plate of the inner frame 3; align the pull ring with the nail hole 31 of the inner frame 3; pass the pin through the nail hole 31 and the pull ring to hang the inner frame 3 at the front end with the pull ring of the tension clamp.

[0030] The third step is to tighten the insulated wire: repeatedly pull the handle of the tensioner back and forth to operate the tensioner to tighten the insulated wire and adjust the sag of the insulated wire; at this time, the outer frame 2, the inner frame 3, the pull bolt 4 and the pull ring all bear the tension of the insulated wire.

[0031] The fourth step is to assemble the wedge core and pre-tighten it: fit the groove of the wedge core with the outer skin of the insulated wire and align them; slide backward along the insulated wire so that the wedge core enters the inner cavity of the wire clamp body; the hook plate 11 of the core hook 1 moves up and down under the elastic force of the torsion spring and hooks the front end of the wedge core; the core hook 1 hooks the front end of the wedge core, and the notch 15 of the hook plate 11 passes through the insulated wire;

[0032] At this time, the nut 34 is located at the rear end of the pull bolt 4. Therefore, the head of the pull bolt 4 is screwed with a wrench to drive the pull bolt 4 to rotate in the opposite direction, so that the head of the pull bolt 4 moves backward relative to the nut 34; so that the core hook 1 and the outer frame 2 move backward, and the wedge core and the insulated wire can also be driven to move backward synchronously; there is no relative movement between the wedge core and the insulated wire, and the insulated wire in front of the tensioner remains in a relaxed state;

[0033] The wedge-shaped body and the wedge core produce a lateral squeezing effect, which gradually increases the gripping force of the wedge core on the insulated wire. When the twisting resistance of the wrench is significantly reduced, the wedge core no longer moves backward and the twisting ends. At this time, the wedge core, the core hook 1 and the outer frame 2 all bear the tension of the insulated wire, and the inner frame 3, the pull bolt 4 and the pull ring no longer bear the tension. The insulated wire in front of the tensioner remains in a relaxed state. The gripping force of the wedge core on the insulated wire at this time, that is, the pre-tightening force, is recorded as F 1 , caused by tension in the insulated wire, is certain.

[0034] Step 5: loosen and remove the installation tool: slowly loosen the tensioner, the insulated wire in front of the tensioner is gradually tightened, so that the insulated wire tends to move backward, and the friction between the wedge core and the insulated wire gradually increases; when the tensioner is completely relaxed, remove the installation tool and the tensioner; at this time, the wedge core completely relies on its grip to generate friction against the tension of the insulated wire; the grip of the wedge core on the insulated wire is recorded as F 2 If factors such as wind, vibration and dancing are ignored, the tension of the insulated wire before and after the tensioner is relaxed is the same, so F 1 =F 2 ; That is to say: the pre-tightening force obtained by using the installation tool and method is the same as the gripping force required during line operation and is certain; therefore, the gripping force obtained by pre-tightening using the installation tool and method can meet the needs of line operation, avoid obvious slippage, prevent outer skin tearing and line running, and ensure safety.

[0035] Supplementary explanation: (1) The pin hole 13 at the rear end of the core hook 1 and the plate hole 21 at the front end of the outer frame 2 pass through the pin shaft, and the pin shaft penetrates the torsion spring to form an elastic hinge; the elastic hinge enables the core hook 1 to rotate relative to the outer frame 2 to avoid interference; it also enables the core hook 1 to rely on the elastic force of the torsion spring to overcome its gravity and maintain its relative position with the outer frame 2, simplifying the installation operation process and avoiding the sagging and shaking of the core hook 1. Therefore, the elastic force design of the torsion spring should consider being able to overcome the gravity of the core hook 1, and also consider avoiding affecting the operation process of inserting the wedge core into the wire clamp body to avoid increasing the difficulty of operation.

[0036] (2) The nail hole 31 of the inner frame 3 and the pull ring of the tension clamp pass through the pin together, so that the inner frame 3 is connected to the pull ring at the front end. Therefore, when installing manually, the pin should be prevented from being lost or accidentally dropped; it is preferred to connect the pin to the installation tool through a rope or chain, which does not affect the insertion and removal operation of the pin and can also effectively prevent the pin from being lost or accidentally dropped. When installing by robot operation, it is preferred that the manipulator has a pin and drives the pin to perform the insertion and removal operation, which is simple and quick.

[0037] (3) In order to avoid interference, when the pin is passed through the nail hole 31 and the pull ring to achieve the connection between the inner frame 3 and the pull ring at the front end, it is preferred to rotate the installation tool to adjust the angle of the inner frame 3 relative to the tension clamp so that the nail hole 31 and the pull ring are aligned to avoid interference with the core hook 1.

[0038] (4) The vertical plate of the outer frame 2 has a longitudinal sleeve hole 23 in the middle, and the sleeve 24 is fixed through the sleeve hole 23; the sleeve 24 is a longitudinal cylindrical structure, passes through the sleeve hole 23, and is interference fit with it. In order to improve the fastening effect and avoid relative rotation, the sleeve 24 and the sleeve hole 23 can have non-rotating structures such as planes, protrusions or grooves at the matching parts, and are matched through the non-rotating structures. In addition, the pull bolt 4 passes through the sleeve 24 and is connected to the inner frame 3 to improve the structural strength and avoid wear of the vertical plate and its sleeve hole 23; therefore, the sleeve 24 should be made of a material that is more wear-resistant than the outer frame 2.

[0039] (5) The NXJ type tension clamp has a hanging point at the front end of the clamp body, through which the insulator or other hardware is connected; the pull ring is located on the side of the clamp body at the rear end. Therefore, when the pre-tightening operation is performed in the fourth step of the installation method, the clamp body bears the tension of the insulated wire; the tension passes through the center of the hanging point and the pull ring, and has a slight deflection angle relative to the axis of the inner cavity of the clamp body; so that the direction of the tension has a slight deflection angle relative to the wedge core. When the hook plate 11 of the core hook 1 hooks the front end of the wedge core, it first contacts the edge of the end face of the front end on the opposite side of the pull ring, so that the deflection angle is reduced. Therefore, during the pre-tightening operation, when the core hook 1 moves backward, it will not cause the wedge core to increase its deflection angle and excessive deflection, which can ensure safe operation. In addition, the excessive deflection of the wedge core requires the bending and stretching of the insulated wire; because the wedge core has a grip on the insulated wire, and the grip gradually increases, the wedge core will not be excessively deflected during the pre-tightening operation, which can ensure safe operation.

[0040] (6) In the fourth step of the installation method, the pull bolt 4 is driven to rotate in the opposite direction, so that the head of the pull bolt 4 moves backward, and the core hook 1 and the outer frame 2 move backward. Because the tensioner is connected to the hook hole 26 of the outer frame 2 through the hook, the tensioner clamps the insulated wire; therefore, the tensioner also moves backward synchronously with the insulated wire. The speed and distance of the backward movement of the insulated wire, the tensioner, the core hook 1 and the outer frame 2 are equal, so there is no relative movement between the wedge core and the insulated wire, and the insulated wire in front of the tensioner can remain in a relaxed state.

[0041] The beneficial effects of the present invention are as follows: (1) The installation tool of the present invention hooks the wedge core of the tension clamp through the hook plate 11 of the core hook 1, hangs the hook of the tensioner through the hook hole 26 of the outer frame 2, connects the pull ring of the tension clamp through the inner frame 3, and drives the pull bolt 4 to rotate in the opposite direction through a wrench to perform a pre-tightening operation.

[0042] The existing NXJ type tension clamp is installed by manual impact pre-tightening; in the specific construction process, it is common to use readily available wrenches, hammers or hardware and other heavy objects to hit the wedge core for pre-tightening. In manual impact pre-tightening, human factors have a greater impact, and the obtained pre-tightening force is uncertain. When the pre-tightening force is insufficient, obvious slippage or line deviation will occur, affecting construction safety; it will also cause the relative slippage of the outer skin of the insulated wire to be large, easy to tear, and affect the operation safety of the distribution line. Especially in the hot summer, the high temperature weather causes the outer skin of the wedge core and the insulated wire to be soft and easy to deform, which is more likely to cause obvious slippage, outer skin tearing and line deviation. The wire clamp body of the NXJ type tension clamp adopts a C-shaped opening structure with a wedge-shaped inner cavity; therefore, when the pre-tightening force is too large, due to the self-locking effect of the wedge, the lateral pressing force of the wire clamp body relative to the wedge core is too large, resulting in excessive deformation of the wire clamp body and the wedge core, which is prone to plastic deformation and damage. In addition, the impact point, impact force size and direction of the manual impact pre-tightening operation are uncertain, which can easily damage the wire clamp body, wedge core and insulated wire, affecting construction safety and operation safety.

[0043] Therefore, compared with the existing artificial impact pre-tightening method of the NXJ type tension clamp, the present invention uses the installation tool to connect the tension clamp and the tensioner, and drives the pull bolt 4 to rotate in the opposite direction through a wrench to perform the pre-tightening operation. The pre-tightening force obtained by using the installation tool and method is the same as the gripping force required in line operation, and is certain; therefore, the gripping force obtained by pre-tightening using the installation tool and method can meet the needs of line operation, avoid obvious slippage, prevent skin tearing and line running, and ensure safety.

[0044] In addition, the present invention does not utilize the impact of a heavy object for pre-tightening, has no impact point, and will not damage the wire clamp body, the wedge core, and the insulated wire, thereby ensuring safety.

[0045] (2) The installation tool and method of the present invention uses a wrench to drive the pull bolt 4 to rotate in the opposite direction, driving the pull bolt 4 to move backward, so that the core hook 1 and the outer frame 2 move backward. The tensioner is hooked with the hook hole 26 of the outer frame 2, clamps the insulated wire, and bears the tension of the insulated wire; therefore, the wedge core, the insulated wire, the tensioner, the core hook 1 and the outer frame 2 all move backward synchronously, and the speed and distance of their backward movement are equal. Therefore, there is no relative movement between the wedge core and the insulated wire, and the insulated wire in front of the tensioner can remain in a relaxed state.

[0046] The existing artificial impact pre-tightening method of the NXJ type tension clamp uses a heavy object to impact the two independent parts of the wedge core that cooperate with each other, causing the wedge core to move backward relative to the clamp body. Since the insulated wire is clamped by the tensioner, the wedge core will also tend to move backward relative to the insulated wire. When the tensioner is close to the clamp body and the insulated wire is thicker, the wedge core will move significantly backward relative to the insulated wire. As the pre-tightening force gradually increases, coupled with the uncertain impact point and impact force, the outer skin of the insulated wire and the strands it wraps will cause relative slippage, or even separation and tearing, affecting the safe operation of the distribution line.

[0047] Therefore, compared with the manual impact pre-tensioning method of the existing NXJ type tension clamp, the installation tool and method of the present invention can make the tensioner, wedge core and insulated conductor move backward synchronously during the pre-tensioning operation, and there is no relative movement between the wedge core and the insulated conductor. The insulated conductor in front of the tensioner remains in a relaxed state and is not subjected to longitudinal force, which can effectively avoid damage to the insulated conductor and ensure the safe operation of the distribution line.

[0048] (3) In the first step of preparing the installation tool, the installation method of the present invention drives the pull bolt 4 to rotate forward so that the nut 34 is located at the rear end of the pull bolt 4; in the fourth step of assembling the wedge core and pre-tightening, the pull bolt 4 is driven to rotate in the opposite direction to move the pull bolt 4 backward. Therefore, in the pre-tightening operation, only the screwing operation of loosening the pull bolt 4 is performed, which can save operating energy and make the pre-tightening operation more convenient. Compared with the existing manual impact pre-tightening method, the present invention can greatly reduce the risk of pre-tightening operation, avoid accidental injuries, and ensure safe operation.

[0049] In addition, since the present invention rotates the pull bolt 4 in the opposite direction to make the wedge core and the insulated wire move backward synchronously, and uses the thread to slow down the backward movement speed, the pre-tightening process can be greatly slowed down, and violent stress fluctuations can be effectively avoided, and impact on the wire clamp body can be avoided. It can also effectively avoid excessive deformation and damage to the wire clamp body and the wedge core, thereby ensuring safe operation.

[0050] (4) The installation tool and method of the present invention uses a wrench to drive the pull bolt 4 to rotate and perform the pre-tightening operation. Compared with the existing manual impact pre-tightening method, the present invention completely changes the working principle of the pre-tightening operation. It is not only convenient to operate, saves operating energy, and ensures safety, but also facilitates robot operation, which is in line with the development trend of "machines replacing people".

[0051] In addition, in the first and fourth steps of the installation method, the screwing process of the pull bolt 4 is controlled by significantly increasing and decreasing the screwing resistance, which is convenient for obtaining data using sensors and for realizing control using computers.

[0052] (5) During the installation process of the tension clamp, the core hook 1, the outer frame 2, the inner frame 3 and the pull bolt 4 of the installation tool of the present invention are all subjected to longitudinal tensile force; therefore, the installation tool can greatly reduce the structural size, reduce the weight, reduce the cost and increase the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a schematic diagram of the overall structure of the installation tool;

[0054] Figure 2 It is a left side view of the core hook 1;

[0055] Figure 3 is a top view of the outer frame 2;

[0056] Figure 4 It is a right side view of the outer frame 2;

[0057] Figure 5 It is a top view of the inner frame 3.

[0058] Explanation of the accompanying drawings: core hook 1, hook plate 11, pull plate 12, pin hole 13, reinforcing rib 14, notch 15, outer frame 2, plate hole 21, external viewing hole 22, sleeve hole 23, sleeve 24, wire groove 25, hook hole 26, inner frame 3, nail hole 31, internal viewing hole 32, through hole 33, nut 34, lower bend 35, transverse bend 36, pull bolt 4, cotter pin 41, stop nut 42. DETAILED DESCRIPTION

[0059] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments:

[0060] Figure 1 It is a schematic diagram of the overall structure of the installation tool, which includes a core hook 1, an outer frame 2, an inner frame 3 and a pull bolt 4. Figure 1 The wire clamp body of the NXJ type tension clamp is drawn with double-dotted lines; the wire clamp body opens downward, has a pull ring on the upper side of the rear end, and has a hanging point on the front end.

[0061] Figure 2 The left side view of the core hook 1; the core hook 1 is an L-shaped hook-shaped curved plate, comprising a hook plate 11 and a pull plate 12; the hook plate 11 is a plate-like structure erected horizontally, fixedly connected to the pull plate 12 at the upper end, and bent downward relative to the pull plate 12; the hook plate 11 is bent backward at the lower end, presenting a hook shape; the hook plate 11 has a notch 15 at the lower part. The pull plate 12 is a straight plate placed horizontally, fixedly connected to the upper end of the hook plate 11 at the front end; the pull plate 12 has a horizontal pin hole 13 at the rear end; the front surface of the hook plate 11 and the upper surface of the pull plate 12 are both provided with reinforcing ribs 14. The core hook 1 and the above structure are preferably integrally die-casted with aluminum alloy material. The hook plate 11 has a flexible wear-resistant layer on the rear surface; the wear-resistant layer is preferably made of synthetic rubber, and the connection between the wear-resistant layer and the rear surface of the hook plate 11 is preferably adhesive.

[0062] Figure 3 is a top view of the outer frame 2; Figure 4 The right side view of the outer frame 2. The outer frame 2 is a frame-shaped structure, including a left side plate, a right side plate and an upper connecting plate; it is bent downward at the rear to form a horizontal vertical plate, with a plate hole 21 at the front end, an external viewing hole 22 at the front of the upper connecting plate, a longitudinal sleeve hole 23 in the middle of the vertical plate, a longitudinal wire groove 25 on the lower surface of the rear, and a hook hole 26 at the rear end. The left side plate and the right side plate have the same structure, both are longitudinal vertical curved plates, straight in the longitudinal direction, bent up and down, and the upper edges at the front are fixedly connected to the upper connecting plate, so that the cross section of the outer frame 2 at the front presents an inverted U-shaped structure. The upper connecting plate is a longitudinal flat plate at the front of the outer frame 2, and is fixedly connected to the upper edges of the left side plate and the right side plate at the left and right edges, respectively, so that the outer frame 2 becomes one, presenting a frame-shaped structure. The upper connecting plate, the left side plate and the right side plate are all bent downward at the rear, so that the upper connecting plate forms a horizontal vertical plate at the rear. The upper connecting plate, the left side plate and the right side plate extend backward through the vertical plate, and the left side plate and the right side plate remain longitudinally straight at the lower side of the rear part, forming the longitudinal wire groove 25; the upper connecting plate gradually narrows backward, so that the left side plate and the right side plate gradually approach each other at the upper side of the rear part, and are bonded to each other as a whole at the upper side of the rear end; and a hook hole 26 is provided on the upper side of the rear end bonded to each other as a whole. The wire groove 25 is located on the lower surface of the rear part of the outer frame 2, and the opening faces downward. The hook hole 26 is a horizontal circular through hole. The outer frame 2 and the above-mentioned structure are preferably made of aluminum alloy material and formed by integrated die-casting. The plate hole 21 and the sleeve hole 23 are preferably obtained in the forming process, and can also be formed by cutting.

[0063] The plate hole 21 and the pin hole 13 of the core hook 1 pass through the pin together; the pin is inserted into the torsion spring to form an elastic hinge, so that the pull plate 12 is elastically hinged with the outer frame 2. The pin is preferably realized by an existing standard pin; the torsion spring is preferably realized by a known torsion spring product. The sleeve 24 is a cylindrical structure with an inner hole and a circular convex edge at the rear end; the inner hole is a smooth hole, which is clearance-matched with the pull bolt 4. The sleeve 24 and the above-mentioned structure are preferably formed by hot forging of medium carbon steel bars. The interference fit between the sleeve 24 and the sleeve hole 23 is preferably achieved by cold pressing.

[0064] Figure 5 The top view of the inner frame 3 is shown in FIG. The inner frame 3 is a frame-shaped structure, including a left curved plate, a right curved plate and an upper curved plate, and an end plate is formed at the rear end. The front ends of the left curved plate and the right curved plate are provided with a transverse nail hole 31, the upper curved plate is provided with an inner viewing hole 32 that passes through from top to bottom, and the middle part of the end plate is provided with a longitudinal through hole 33. The left curved plate and the right curved plate have the same structure, and both include a longitudinally erected straight plate portion and a transversely bent portion 36. Both are fixedly connected to the upper curved plate at the upper edge of the straight plate portion, and both are transversely bent inward at the rear end of the straight plate portion to form the transversely bent portion 36. The upper curved plate includes a longitudinally straight flat plate portion and a lower bent portion 35. The left and right edges of the flat plate portion are respectively fixedly connected to the upper edges of the left curved plate and the right curved plate to form an integral body and present a frame-shaped structure, and the rear end of the flat plate portion is bent downward to form the lower bent portion 35. The inner viewing holes 32 are evenly distributed longitudinally on the flat plate portion of the upper curved plate, and pass through from top to bottom. The lower curved portion 35 of the upper curved plate has a longitudinal hole, and the transverse curved portions 36 of the left curved plate and the right curved plate both have arc-shaped notches; the longitudinal hole and the arc-shaped notches are aligned to form the through hole 33. The inner frame 3 and the above structure are preferably formed by stamping and bending a medium carbon steel plate.

[0065] The left curved plate and the right curved plate are both pinned through the nail hole 31 and the pull ring, and are connected to the pull ring at the front end. Therefore, the nail hole 31 and the pin are provided with a stop structure to prevent the pin from accidentally withdrawing from the nail hole 31. The pin and its stop structure are preferably realized by a known standard pin part with a transverse through hole, and a closed pin is passed through the through hole to achieve the stop. The nut 34 is a cylindrical structure with a threaded hole and a circular convex edge at the front end, and is preferably manufactured by the material and process of existing standard nut parts. The interference fit between the nut 34 and the through hole 33 is preferably achieved by cold pressing.

[0066] The pull bolt 4 comprises a screw and a head; the screw is a cylindrical structure with an external thread on the outer surface and a transverse through hole at the front end; the head is located at the rear end of the screw and is fixedly connected to the screw; the head has a screwing structure that can drive the pull bolt 4 to rotate. The screwing structure of the head is preferably hexagonal, and can also be a well-known double hexagon or spline shape. The pull bolt 4 and the above structure are preferably manufactured by the materials and processes of existing standard bolt parts.

[0067] The threaded hole of the nut 34 has an internal thread, and the screw has an external thread, which cooperates with the internal thread of the nut 34; the external thread and the internal thread are preferably implemented by trapezoidal threads. The pull bolt 4 has a cotter pin 41 and a stop nut 42 at the front end of the screw; the cotter pin 41 is preferably implemented by an existing cotter pin standard part. The stop nut 42 is preferably implemented by an existing slotted nut standard part, and its slot is used as a stop structure to cooperate with the cotter pin 41 to achieve stoppage and prevent rotation and falling off.

[0068] In the first step of the installation method, the head of the pull bolt 4 is screwed with a wrench so that the nut 34 is located at the rear end of the pull bolt 4; this preparation process can also be completed after the installation tool is loosened and removed in the fifth step, so as to facilitate the storage and use of the installation tool. In the first and fourth steps of the installation method, the perception of the obvious increase and decrease of the screwing resistance is preferably achieved by a digital torque wrench. In addition, the external thread of the pull bolt 4 and the internal thread of the nut 34 are preferably right-handed threads; therefore, driving the pull bolt 4 to rotate forward in the first step refers to clockwise rotation; driving the pull bolt 4 to rotate reversely in the fourth step refers to counterclockwise rotation.

[0069] The above implementation is only a preferred embodiment of the present invention and does not constitute a limitation of the present invention. Under the condition of meeting the structural and performance requirements of the present invention, changes in materials and manufacturing processes are all within the protection scope of the present invention.

Claims

1. An installation tool for an NXJ type tension clamp, used for fixing the insulated wire tightened by a tensioner to the installation process of the tension clamp, the tension clamp comprising a clamp body and a wedge core, the clamp body having a pull ring, the tensioner having a hook, characterized in that: The installation tool comprises a core hook (1), an outer frame (2), an inner frame (3) and a pull bolt (4). The wedge core of the tension clamp is hooked by the core hook (1). A hook of the tensioner is connected via the outer frame (2). The pull ring is connected via the inner frame (3), Driving the pull bolt (4) to rotate in the opposite direction, so that the wedge core moves relative to the wire clamp body; The installation tool connects the tension clamp and the tensioner, drives the pull bolt (4) to rotate in the opposite direction, and performs a pre-tightening operation; The core hook (1) is an L-shaped hook-shaped curved plate, comprising a hook plate (11) and a pull plate (12); the wedge core is hooked by the hook plate (11), and the pull plate (12) is elastically hinged to the outer frame (2) to perform a pre-tightening operation; The outer frame (2) is a frame-shaped structure, comprising a left side plate, a right side plate and an upper connecting plate, accommodating the inner frame (3) and the pull bolt (4) at the front, forming a vertical plate at the rear, with a sleeve hole (23) and a sleeve (24) in the middle of the vertical plate, a wire groove (25) on the lower surface of the rear, and a hook hole (26) at the rear end; The inner frame (3) is a frame-shaped structure, comprising a left curved plate, a right curved plate and an upper curved plate, forming an end plate at the rear end, having a nail hole (31) at the front end, and having a through hole (33) and a nut (34) in the middle of the end plate; The obtained preload force is certain, so that the gripping force of the tension clamp can meet the needs of line operation, avoid obvious slippage, prevent outer skin tearing and line running, and ensure safety.

2. The installation tool for the NXJ type tension clamp according to claim 1, characterized in that: The hook plate (11) is a plate-like structure, fixedly connected to the pull plate (12) at the upper end, and bent downward relative to the pull plate (12) to present a hook shape, abutting against and pressing against the front end of the wedge core to hook the wedge core and perform a pre-tightening operation; The hook plate (11) has a notch (15) at the bottom, and the insulated wire is passed through the notch (15) to avoid interference; The hook plate (11) is bent backward at the lower end to present a hook shape, thereby ensuring safe operation.

3. The installation tool for the NXJ type tension clamp according to claim 1, characterized in that: The pull plate (12) has a transverse pin hole (13) at the rear end; The outer frame (2) has a plate hole (21) at the front end; The plate hole (21) is a transverse through hole, and passes through a pin together with the pin hole (13) of the core hook (1), so that the front end of the outer frame (2) is elastically hinged to the rear end of the core hook (1), so that the core hook (1) generates a backward pulling force to perform a pre-tightening operation; The pin shaft is inserted into the torsion spring to form an elastic hinge, so that the pull plate (12) is elastically hinged to the outer frame (2); the core hook (1) can rotate relative to the outer frame (2) to avoid interference; and the core hook (1) can maintain a relative position with the outer frame (2).

4. The installation tool for the NXJ type tension clamp according to claim 1, characterized in that: A hook of a wire tensioner is hooked through the hook hole (26), so that the outer frame (2) bears the tension of the insulated wire and performs pre-tightening; The left side plate and the right side plate have the same structure and are both longitudinal vertical curved plates, which are longitudinally straight and are fixedly connected to the upper connecting plate at the upper edge of the front part to accommodate the inner frame (3) and the pull bolt (4), so that the pull bolt (4) can drive the inner frame (3) to move longitudinally by rotating; The left plate and the right plate both have plate holes (21) at the front ends; The sleeve hole (23) clamps the sleeve (24) so ​​that the pull bolt (4) passes through the sleeve (24), thereby improving the structural strength and the service life; The wire slot (25) opens downward to accommodate insulated wires and avoid interference.

5. The installation tool for the NXJ type tension clamp according to claim 4, characterized in that: The upper connecting plate, the left side plate and the right side plate are all bent downward at the rear, so that the upper connecting plate forms a transversely erected vertical plate at the rear; The upper connecting plate, the left side plate and the right side plate extend backward through the vertical plate, and the left side plate and the right side plate remain longitudinally straight at the lower side of the rear portion to form the wire groove (25); The upper connecting plate gradually narrows toward the rear, so that the left side plate and the right side plate gradually approach each other at the upper side of the rear portion, and are attached to each other at the upper side of the rear end and have hook holes (26); The sleeve (24) is a cylindrical structure with an inner hole and a convex edge at the rear end; The sleeve (24) is fitted with the vertical plate via the convex edge, so that the sleeve (24) is fixed to the sleeve hole (23) to obtain fixation and support; The inner hole of the sleeve (24) is a light hole, which is clearance-matched with the pull bolt (4), so that the pull bolt (4) can move and rotate longitudinally relative to the sleeve (24).

6. The installation tool for the NXJ type tension clamp according to claim 1, characterized in that: A pin is passed through the nail hole (31) and the pull ring, and is hooked to the pull ring at the front end. At the rear end, the nut (34) cooperates with the pull bolt (4) to bear the tension of the insulated wire, so that the pull ring bears the backward pulling force. It is also possible to drive the pull bolt (4) to rotate in the opposite direction, causing the outer frame (2) to move backward, so that the wedge core obtains the tension of the insulated wire and performs a pre-tightening operation.

7. The installation tool for the NXJ type tension clamp according to claim 6, characterized in that: The nut (34) has a threaded hole and a circular convex edge at the front end, which passes through the through hole (33) and is interference-fitted therewith; the convex edge is fitted with the end plate so that the nut (34) is fixed to the through hole (33) to obtain fixation and support; The threaded hole of the nut (34) has an internal thread, and the internal thread cooperates with the pull bolt (4) so ​​that the pull bolt (4) rotates, thereby driving the inner frame (3) to move longitudinally relative to the outer frame (2).

8. The installation tool for the NXJ type tension clamp according to claim 7, characterized in that: The pull bolt (4) comprises a screw rod and a head, is subjected to a tensile force, and passes through the outer frame (2) so that the head is exposed from the outer frame (2) to facilitate screwing with a wrench for pre-tightening operation; The screw rod has an external thread, and the external thread cooperates with the internal thread of the nut (34), so that the pull bolt (4) rotates, which can drive the nut (34) to move relative to the longitudinal direction.

9. A method for installing an NXJ type tension clamp, using the installation tool according to any one of claims 1 to 8, for fixing an insulated conductor to the tension clamp, characterized in that: The following steps are involved: The first step is to screw the pull bolt (4) to drive the pull bolt (4) to rotate in the forward direction, thereby driving the inner frame (3) to move backward relative to the outer frame (2); observing the relative position and movement of the inner frame (3); and ending the screwing when the screwing resistance increases significantly; Hanging the installation tool on the wire tensioner; The second step is to connect the tension clamp to the insulator and install it on the cross arm of the tower; and use the tensioner to clamp the insulated wire; The inner frame (3) is hung at the front end with the pull ring of the tension clamp; The third step is to operate the wire tightener to tighten the insulated wire; The fourth step is to slide the wedge core along the insulated wire so that the wedge core enters the wire clamp body; and the core hook (1) hooks the front end of the wedge core; The pull bolt (4) is screwed to drive the pull bolt (4) to rotate in the opposite direction, thereby driving the pull bolt (4) to move backward; the wedge core and the insulated wire are driven to move backward synchronously; and the insulated wire in front of the tensioner is kept in a relaxed state; When the twisting resistance is significantly reduced, the wedge core no longer moves backward and the twisting ends; Step 5: loosen the tensioner, and the insulated wire in front of the tensioner is gradually tightened; when the tensioner is completely loosened, remove the installation tool and the tensioner.

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