Horizontal directional drilling back-reaming construction pipe anticorrosion device

Abstract

The application discloses a kind of horizontal directional drilling back drag construction protective pipeline anticorrosion device, relating to horizontal directional drilling back drag technical field, including fixed seat and moving seat, the top of fixed seat and moving seat is respectively fixedly installed with fixed fork and moving fork, the inside of fixed fork and moving fork is provided with rolling mechanism, the inside both sides of moving fork are provided with clamping mechanism, the clamping mechanism includes the shell fixedly connected with moving fork, the inside of shell is provided with sliding slot one, the inside of shell is provided with telescopic frame with shell rotationally connected and with the sliding cooperation of sliding slot one;The horizontal directional drilling back drag construction protective pipeline anticorrosion device, by setting fixed seat, convex block one, convex block two, switch mechanism, button mechanism, the mutual cooperation of clamping mechanism, so that pipeline is put into clamping mechanism can automatically clamp pipeline, moving seat is contacted with fixed seat or other moving seat, can make that electro-hydraulic push rod is automatically retracted, so that clamping mechanism is automatically loosened.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of horizontal directional drilling back dragging technology, and particularly relates to a horizontal directional drilling back dragging construction protective pipeline anticorrosion device. BACKGROUND

[0002] The horizontal directional drilling machine is a kind of construction machinery for laying various underground public facilities (pipes, cables, etc.) without excavating the ground surface, and is widely used in the laying construction of flexible pipelines such as water supply, power supply, telecommunications, natural gas, coal gas and oil. It is suitable for sandy soil, clay and other ground conditions, but not suitable for high underground water level and pebble stratum. It can be constructed in most non-hard rock areas in China.

[0003] However, in the process of laying the pipeline by the existing directional drilling back dragging, the pipeline is dragged on the ground, which easily causes the pipeline anticorrosion layer to be abraded. The existing protective device is usually arranged at intervals and has a fixed position. While reducing the frictional damage to the anticorrosion layer during pipeline laying, the part of the device located at the tail of the pipeline cannot move with the pipeline, so that when the tail of the pipeline is moved between the two auxiliary devices, the long interval between the two auxiliary devices causes the tail of the pipeline to be dragged on the ground, the anticorrosion layer of the tail of the pipeline is abraded, and the interval between the two auxiliary devices is shortened, which increases the number of auxiliary devices to be arranged, and increases the construction difficulty and cost. SUMMARY

[0004] The present application aims to provide a horizontal directional drilling back dragging construction protective pipeline anticorrosion device to solve the above problems in the prior art.

[0005] In order to achieve the above-mentioned purpose, the present application provides the following technical scheme: a horizontal directional drilling back dragging construction protective pipeline anticorrosion device, comprising a fixed seat and a movable seat, the top of the fixed seat and the movable seat is respectively fixedly installed with a fixed fork and a movable fork, the inner side of the fixed fork and the movable fork is provided with a rolling mechanism, the inside of the movable fork is provided with a clamping mechanism on both sides, the clamping mechanism comprises an outer shell fixedly connected with the movable fork, a sliding groove one is formed in the inside of the outer shell, a telescopic frame is arranged in the inside of the outer shell and is rotationally connected with the outer shell and is in sliding cooperation with the sliding groove one, an electro-hydraulic push rod is rotationally connected in the inside of the outer shell and can drive the telescopic frame to extend and retract, a clamping plate connected with the telescopic frame is slidingly connected at the opening of the outer shell, the side surface of the movable seat and the fixed seat is respectively fixedly connected with a second protruding block and a first protruding block, a spring damper is fixedly connected to the bottom of the movable seat, a wheel is rotationally connected to the bottom of the spring damper, an opening away from the second protruding block is formed in the inside of the movable seat, a switch mechanism and a button mechanism are arranged in the inside of the opening and are in cooperation, and the opening can be inserted by the first protruding block and the second protruding block.

[0006] Further, the rolling mechanism comprises a bottom roller and lateral rollers, the bottom roller is rotationally connected to the inner bottom of the fixed fork and the moving fork, and the lateral rollers are rotationally connected to the inner sides of the fixed fork and the moving fork.

[0007] Further, the clamping plate comprises a connecting plate, a sliding groove two is arranged on the surface of the connecting plate, the connecting plate is rotationally connected with the telescopic frame, and the connecting plate is slidingly connected with the telescopic frame through the sliding groove two, one end close to the center of the connecting plate is fixedly connected with a button one, a sliding column is slidingly inserted into the right side of the connecting plate, and a button two is fixedly connected, one end away from the connecting plate of the sliding column is fixedly connected with a clamping plate, and the surface of the sliding column is sleeved with a compression spring one which is in contact with the connecting plate and the clamping plate.

[0008] Further, the button one is connected in series on the shortening circuit of the electro-hydraulic push rod, and the button two is connected in series on the elongation circuit of the electro-hydraulic push rod.

[0009] Further, the switch mechanism comprises a push rod slidingly connected in the switch cavity, the surface of the push rod is rotationally connected with a tension spring, and the lower end of the tension spring is rotationally connected with a swing arm rotationally connected in the switch cavity.

[0010] Further, the switch mechanism further comprises a connecting rod rotationally connected with the push rod, the end away from the push rod of the connecting rod is rotationally connected with a sliding rod, the sliding rod is slidingly connected in the moving seat and extends out of the moving seat.

[0011] Further, the button mechanism comprises a switch shell fixedly connected in the moving seat, a key is slidingly inserted into one end of the switch shell and extends into the switch cavity, the inside of the switch shell is slidingly connected with a movable contact plate fixedly connected with the key, the inside of the switch shell is fixedly connected with a static contact one and a static contact two located on the two sides of the movable contact plate, and the inside of the switch shell is fixedly connected with a compression spring two having one end fixedly connected with the movable contact plate.

[0012] Further, the static contact one has two and is fixedly connected on the elongation circuit of the electro-hydraulic push rod, and the static contact two has two and is fixedly connected on the shortening circuit of the electro-hydraulic push rod.

[0013] 1. Compared with the prior art, the horizontal directional drilling back dragging construction protective pipeline anticorrosion device provided by the application can make the moving seat move with the pipeline through the cooperation of the moving seat, the spring damper and the wheels, so that the moving seat can move with the pipeline when the pipeline is dragged to move, and the contact between the tail end of the pipeline and the ground is prevented to avoid the abrasion of the anticorrosion layer.

[0014] 2、Compared with the prior art, the horizontal directional drilling back dragging construction protective pipeline anticorrosion device provided by the application can make the pipeline stop after being clamped by the clamping mechanism by pressing the sliding rod of the switch mechanism, and the moving seat can move with the pipeline, when the moving seat contacts with the fixed seat or other moving seats, the electro-hydraulic push rod can be automatically retracted and stopped, the clamping mechanism can be automatically released, and the pipeline can be dragged away and into the back dragging cylinder. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments described in the present application, and other drawings can also be obtained by those skilled in the art according to these drawings.

[0016] Figure 1 The overall structure schematic diagram provided by the first embodiment of the present application is shown in the figure.

[0017] Figure 2 The overall structure schematic diagram provided by the second embodiment of the present application is shown in the figure.

[0018] Figure 3 Another overall structure schematic diagram provided by the second embodiment of the present application is shown in the figure.

[0019] Figure 4 The clamping mechanism schematic diagram provided by the second embodiment of the present application is shown in the figure.

[0020] Figure 5 The switch mechanism schematic diagram provided by the second embodiment of the present application is shown in the figure.

[0021] Figure 6 The A part enlarged view of the second embodiment of the present application is shown in the figure. Figure 5

[0022] Figure 7 The switch mechanism part top view provided by the second embodiment of the present application is shown in the figure.

[0023] Explanation of reference signs:

[0024] ​11, fixed seat; 12, convex block one; 13, fixed fork; 21, bottom roller; 22, lateral roller; 31, moving seat; 32, convex block two; 33, spring damper; 34, wheel; 35, moving fork; 36, switch cavity; 41, shell; 42, sliding groove one; 43, telescopic frame; 44, electro-hydraulic push rod; 45, clamping plate; 451, connecting plate; 452, sliding groove two; 453, button one; 454, button two; 455, sliding column; 456, compression spring one; 457, clamping plate; 51, push rod; 52, tension spring; 53, swing arm; 54, connecting rod; 55, sliding rod; 61, switch shell; 62, key; 63, moving contact plate; 64, static contact one; 65, static contact two; 66, compression spring two. DETAILED DESCRIPTION

[0025] In order to make the technical personnel in the art better understand the technical solutions of the present application, the present application will be further described in detail below in conjunction with the drawings.

[0026] Example one:

[0027] Please refer to Figure 1 A horizontal directional drilling back dragging construction protective pipeline anticorrosion device, comprising a fixed seat 11, the top of the fixed seat 11 is fixedly installed with a fixed fork 13, the inner side of the fixed fork 13 is provided with a rolling mechanism, and one side surface of the fixed seat 11 is fixedly connected with a convex block one 12.

[0028] The rolling mechanism comprises a bottom roller 21 and a lateral roller 22, the bottom roller 21 is rotatably connected to the inner bottom of the fixed fork 13, and there are two bottom rollers 21, which are parallel, and the surfaces of the front and rear two bottom rollers 21 respectively extend out of the front and rear two side surfaces of the fixed fork 13, and the lateral roller 22 is rotatably connected to the inner sides of the fixed fork 13, and there are two parallel lateral rollers 22 rotatably connected to each side, and the surfaces of the front and rear two lateral rollers 22 respectively extend out of the front and rear two side surfaces of the fixed fork 13.

[0029] Example two:

[0030] Please refer to Figures 2-7The embodiment provides a technical scheme based on the embodiment one: the mobile seat 31 is provided with the mobile fork 35 fixedly installed on the top of the mobile seat 31, and the inner side of the mobile fork 35 is provided with a rolling mechanism; the mobile fork 35 is different from the fixed fork 13 in that the inner sides of the mobile fork 35 are provided with clamping mechanisms, the clamping mechanisms comprise the shell 41 fixedly connected with the mobile fork 35, the shell 41 is located on the two sides of the lateral roller 22, the inner side of the shell 41 is provided with the sliding groove one 42, the inner side of the shell 41 is provided with the telescopic support 43 rotationally connected with the shell 41 and in sliding connection with the sliding groove one 42, the telescopic support 43 is composed of a plurality of support rods hinged with each other, the centers of every two support rods are hinged into an X shape, the left ends of the two support rods forming the X shape are hinged with each other, and the left end of one of the two support rods forming the X shape is rotationally connected with the shell 41, and the left end of the other support rod is in sliding connection with the sliding groove one 42; the electro-hydraulic push rod 44 capable of driving the telescopic support 43 to extend and retract is rotationally connected with the inner side of the shell 41, the electro-hydraulic push rod 44 adopts a DYTZ type integral straight electro-hydraulic push rod, the output end of the electro-hydraulic push rod 44 is rotationally connected with one of the support rods of the telescopic support 43, so that the output end of the electro-hydraulic push rod 44 can drive the telescopic support 43 to extend and retract; the clamping plate 45 connected with the telescopic support 43 is in sliding connection with the opening of the shell 41, the convex block two 32 is fixedly connected with the surface of one side of the mobile seat 31, the spring damper 33 is fixedly connected with the bottom of the mobile seat 31, the spring damper 33 is composed of a compression spring and a damper, the compression spring is sleeved on the telescopic end of the damper, and the two ends are fixedly connected with the damper body and the damper output end respectively, and the spring damper 33 serves as a suspension of the wheel 34, so that the wheel 34 can be attached to the uneven bottom surface, and the stability of the mobile seat 31 and the mobile fork 35 is ensured; the wheel 34 is rotationally connected with the bottom of the spring damper 33, the switch cavity 36 away from the convex block two 32 is formed in the inner side of the mobile seat 31, the switch mechanism and the button mechanism matched with each other are arranged in the inner side of the switch cavity 36, and the switch cavity 36 can be inserted by the convex block one 12 and the convex block two 32.

[0031] The surfaces of the front and rear two bottom rollers 21 respectively extend out of the front and rear two side surfaces of the mobile fork 35, the lateral rollers 22 are rotationally connected with the inner sides of the mobile fork 35, two parallel lateral rollers 22 are rotationally connected with each side, and the clamping mechanisms are arranged on the sides away from each other of the two lateral rollers 22.

[0032] The clamping plate 45 comprises a connecting plate 451, the surface of the connecting plate 451 is provided with a sliding groove two 452, the connecting plate 451 is rotationally connected with the telescopic frame 43, and the connecting plate 451 is slidingly connected with the telescopic frame 43 through the sliding groove two 452, the rightmost end of the connecting plate 451 is provided with two support rods in X shape, one of the two support rods is rotationally connected with the connecting plate 451, and the other support rod is slidingly connected with the sliding groove two 452; the end, close to the center of the connecting plate 451, of the sliding groove two 452 is fixedly connected with a button one 453, the right side of the connecting plate 451 is slidingly inserted with a sliding column 455, and the sliding column 455 is fixedly connected with a button two 454, the button one 453 and the button two 454 are both dynamic break switches, that is, in a normal state, the switch contact is a kind of button that is connected, and is disconnected when touched, and is closed when released, and the button one 453 and the button two 454 are both LA36M type buttons; the end, away from the connecting plate 451, of the sliding column 455 is fixedly connected with a clamping plate 457, and the surface of the sliding column 455 is sleeved with a compression spring one 456, which is in contact with the connecting plate 451 and the clamping plate 457 at two ends.

[0033] The button one 453 is connected in series on the shortening circuit of the electro-hydraulic push rod 44, when the shortening circuit is connected, the oil pump in the electro-hydraulic push rod 44 pumps oil into the hydraulic cylinder at the output end, and the output end is shortened; the button two 454 is connected in series on the lengthening circuit of the electro-hydraulic push rod 44, when the lengthening circuit is connected, the oil pump in the electro-hydraulic push rod 44 pumps oil into the hydraulic cylinder at the output end, and the output end is lengthened.

[0034] The switch mechanism comprises a push rod 51 slidingly connected in the switch cavity 36, the surface of the push rod 51 is rotationally connected with a tension spring 52, the lower end of the tension spring 52 is rotationally connected with a swing arm 53 rotationally connected at the upper end in the switch cavity 36, and two stop blocks are fixedly connected on the inner wall of the switch cavity 36, so as to prevent the swing arm 53 from rotating more than ninety degrees to the two sides, so that when the push rod 51 drives the swing arm 53 to rotate more than a vertical angle through the tension spring 52, the swing arm 53 limits the push rod 51 at the position after being pushed through the tension spring 52.

[0035] The switch mechanism further comprises a connecting rod 54 rotationally connected with the push rod 51, the end, away from the push rod 51, of the connecting rod 54 is rotationally connected with a sliding rod 55, the sliding rod 55 is slidingly connected in the moving seat 31, and the end of the sliding rod 55 extends out of the moving seat 31, so as to facilitate pressing the sliding rod 55 from the outside of the moving seat 31 to make the push rod 51 move left to leave the key 62.

[0036] The button mechanism comprises a switch shell 61 fixedly connected in the moving seat 31, the end of the switch shell 61 is slidingly inserted with a key 62, and the key 62 extends into the switch cavity 36, the inside of the switch shell 61 is slidingly connected with a moving contact plate 63 fixedly connected with the key 62, the inside of the switch shell 61 is fixedly connected with a static contact one 64 and a static contact two 65 located at the two sides of the moving contact plate 63 respectively, and the inside of the switch shell 61 is fixedly connected with a compression spring two 66, one end of which is fixedly connected with the moving contact plate 63.

[0037] The static contact one 64 has two and is fixedly connected on the extension circuit of the electro-hydraulic push rod 44, the static contact two 65 has two and is fixedly connected on the shortening circuit of the electro-hydraulic push rod 44, the two sides of the movable contact plate 63 are fixedly connected with the contacts, when the contacts are respectively contacted with the static contact one 64 and the static contact two 65, the extension circuit and the shortening circuit can be respectively communicated.

[0038] Working principle: when using, first, the fixed seat 11 in the device of example one is installed and fixed near the back-dragging hole, and one side of the convex block one 12 is away from the back-dragging hole. Then every twenty meters or so is placed with the device of example two, and the push rod 51 in the switch cavity 36 of the movable seat 31 is located at the right side inside the switch cavity 36, the button 62 is touched, the button 62 drives the movable contact plate 63 to move to the right, the movable contact on the movable contact plate 63 is contacted with the static contact two 65. When the push rod 51 is located at the right side inside the switch cavity 36, the push rod 51 drives the lower end of the swing arm 53 to swing to the right through the tension spring 52, so that the push rod 51 cannot be swung at will through the cooperation of the tension spring 52 and the swing arm 53, so that the movable contact on the movable contact plate 63 cannot be easily separated from the static contact two 65.

[0039] When the contact on the movable contact plate 63 is contacted with the static contact two 65, the output end of the electro-hydraulic push rod 44 can be shortened, and the button one 453 is locked in the circuit series with the static contact two 65, so that when the button one 453 is touched, the circuit is disconnected, and the electro-hydraulic push rod 44 stops shortening; when the contact on the movable contact plate 63 is contacted with the static contact one 64, the output end of the electro-hydraulic push rod 44 can be extended, and the button two 454 is locked in the circuit series with the static contact one 64, so that when the button two 454 is touched, the circuit is disconnected, and the electro-hydraulic push rod 44 stops extending.

[0040] After the device in example one and example two is arranged, the pipeline is hoisted and placed inside the fixed fork 13 and the moving fork 35, in contact with the bottom roller 21, and the two sides of the pipeline are blocked by the lateral roller 22. Then the sliding rod 55 protruding from the surface of the moving seat 31 is pushed inward, the sliding rod 55 drives the push rod 51 to move left through the connecting rod 54 rotatingly connected thereto, the push rod 51 drives the swing arm 53 to rotate to the left through the tension spring 52, so that the push rod 51 leaves the button 62, the button 62 moves left under the action of the compression spring two 66, so that the moving contact plate 63 moves left and loses contact with the static contact two 65, and contacts with the static contact one 64, so that the electro-hydraulic push rod 44 is elongated, driving the telescopic frame 43 to elongate, the telescopic frame 43 drives the clamping plate 45 to protrude from the shell 41, so that the clamping plate 457 on the clamping plate 45 contacts with the surface of the pipeline, thereby clamping the pipeline from both sides, until the clamping plate 45 is pressed by the telescopic frame 43 and the pipeline, so that the clamping plate 457 extrudes the compression spring one 456 to approach the connecting plate 451, and triggers the button two 454 on the connecting plate 451, so that the electro-hydraulic push rod 44 stops elongating.

[0041] Then the horizontal directional drilling pulls the pipeline to move, when the pipeline moves, the bottom roller 21 on the fixed fork 13 rotates, reducing the abrasion of the pipeline corrosion layer, at the same time, the moving fork 35 clamping the pipeline moves, thereby driving the moving seat 31 to move, so that the moving seat 31 can move with the pipeline, preventing the tail end of the pipeline from contacting the ground and preventing the corrosion layer of the tail end of the pipeline from being abraded.

[0042] And the moving seat 31 is connected with the wheel 34 through the spring damper 33, so that when the wheel 34 encounters uneven road surface, it can stretch and retract to keep close to the ground under the action of the spring damper 33, so that the moving seat 31 and the moving fork 35 remain stable, preventing the moving fork 35 from jolting with the uneven ground and affecting the pipeline placed thereon.

[0043] After the pipe is dragged for a distance, the closest moving seat 31 to the fixed seat 11 contacts the fixed seat 11, so that the protruding block one 12 on the fixed seat 11 is inserted into the switch cavity 36 of the moving seat 31, the push rod 51 in the switch cavity 36 is pushed to move right, the push rod 51 moves to the bottom to push the button 62 to move right, so that the contact on the moving contact plate 63 contacts the static contact two 65, so that the electro-hydraulic push rod 44 is shortened, so that the clamping plate 45 is retracted through the telescopic frame 43, the pipe is loosened, after the clamping plate 45 is retracted, one end of the telescopic frame 43 moves along the sliding groove two 452, the button one 453 is touched to make the electro-hydraulic push rod 44 stop shortening. So that the pipe can move to the moving fork 35, and can drive the bottom roller 21 and the side lateral roller 22 on the moving fork 35 to rotate, so as to prevent the anticorrosive layer from being abraded. The push rod 51 on the rear moving seat 31 is touched by the protruding block two 32 on the front moving seat 31, and the pipe is loosened in the same way, so that the moving seat 31 moves and contacts the previous moving seat 31 or the fixed seat 11, and stops moving, and the pipe can be dragged away from the moving seat 31 and dragged into the drag back hole by the horizontal directional drilling.

[0044] The foregoing merely describes some exemplary embodiments of the present application by way of illustration, and it is needless to say that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present application. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present application.

Claims

1. A horizontal directional drilling back-reaming construction anticorrosion device for protecting a pipeline, comprising a fixed seat (11) and a moving seat (31), characterized in that: The top of the fixed seat (11) and the moving seat (31) is respectively fixedly installed with a fixed fork (13) and a moving fork (35), the inner side of the fixed fork (13) and the moving fork (35) is provided with a rolling mechanism, the inside of the moving fork (35) is provided with a clamping mechanism, the clamping mechanism comprises an outer shell (41) fixedly connected with the moving fork (35), a sliding groove one (42) is arranged in the inside of the outer shell (41), an extension frame (43) is arranged in the inside of the outer shell (41) and is rotatably connected with the outer shell (41) and is slidably connected with the sliding groove one (42), an electro-hydraulic push rod (44) is rotatably connected in the inside of the outer shell (41) and can drive the extension frame (43) to extend or retract, a clamping plate (45) is slidably connected with the opening of the outer shell (41) and is connected with the extension frame (43), the side surface of the moving seat (31) and the fixed seat (11) is respectively fixedly connected with a protruding block two (32) and a protruding block one (12), a spring damper (33) is fixedly connected to the bottom of the moving seat (31), a wheel (34) is rotatably connected to the bottom of the spring damper (33), an opening away from the protruding block two (32) is arranged in the inside of the moving seat (31) and is an opening and closing cavity (36), a switch mechanism and a button mechanism are arranged in the inside of the opening and closing cavity (36) and are matched with each other, and the opening and closing cavity (36) can be inserted by the protruding block one (12) and the protruding block two (32); The rolling mechanism comprises a bottom roller (21) and a lateral roller (22), the bottom roller (21) is rotatably connected to the inner bottom of the fixed fork (13) and the moving fork (35), and the lateral roller (22) is rotatably connected to the inside of the fixed fork (13) and the moving fork (35) on both sides. The clamping plate (45) comprises a connecting plate (451), a sliding groove two (452) is arranged on the surface of the connecting plate (451), the connecting plate (451) is rotatably connected with the extension frame (43) and is slidably connected with the extension frame (43) through the sliding groove two (452), one end of the sliding groove two (452) close to the center of the connecting plate (451) is fixedly connected with a button one (453), a sliding column (455) is slidably inserted into the right side of the connecting plate (451) and is fixedly connected with a button two (454), one end of the sliding column (455) away from the connecting plate (451) is fixedly connected with a clamping plate (457), and the surface of the sliding column (455) is sleeved with a compression spring one (456) having two ends in contact with the connecting plate (451) and the clamping plate (457); The button one (453) is connected in series on the shortening circuit of the electro-hydraulic push rod (44), and the button two (454) is connected in series on the lengthening circuit of the electro-hydraulic push rod (44); The switch mechanism comprises a push rod (51) slidably connected in the opening and closing cavity (36), a stretching spring (52) is rotatably connected to the surface of the push rod (51), and the lower end of the stretching spring (52) is rotatably connected with a swing arm (53) rotatably connected in the opening and closing cavity (36). The switch mechanism further comprises a connecting rod (54) rotatably connected with the push rod (51), one end of the connecting rod (54) rotatably connected with a sliding rod (55), the sliding rod (55) slidably connected in the moving seat (31) and one end of the sliding rod (55) extending out of the moving seat (31); The button mechanism comprises a switch shell (61) fixedly connected in the moving seat (31), one end of the switch shell (61) slidably inserted with a button (62) and the button (62) extending into the switch cavity (36), the switch shell (61) slidably connected with a movable contact plate (63) fixedly connected with the button (62) in the interior of the switch shell (61), the switch shell (61) fixedly connected with a static contact one (64) and a static contact two (65) respectively located on both sides of the movable contact plate (63) in the interior of the switch shell (61), and the switch shell (61) fixedly connected with a compression spring two (66) fixedly connected with the movable contact plate (63) at one end.

2. A device for protecting the anticorrosive coating of a pipe being installed by the horizontal directional drilling back-reaming method, according to claim 1, characterized in that: The static contact one (64) has two and is fixedly connected on the extension circuit of the electro-hydraulic push rod (44), and the static contact two (65) has two and is fixedly connected on the shortening circuit of the electro-hydraulic push rod (44).

Images