Semi-automatic hydraulic stretcher

Abstract

The invention relates to the field of vehicles for climbing operation, and provides a semi-automatic hydraulic stretcher which is characterized in that a hydraulic cylinder, a pull rod and a supporting sleeve are designed to be of an integral structure, when a bolt needs to be stretched, the pull rod can be directly connected with a target screw, and when a wrench assembly slides to a working position meshed with the target nut, the target nut is driven to rotate; according to the technical scheme, the target nut is directly screwed or unscrewed, the connection between the pull rod and the target screw rod needs to be disconnected during disassembly, so that the pre-tightening force control precision is guaranteed, and after the target screw rod is stretched, rotation of the target nut can be achieved under the condition that the torque is small; the situation that the surface of threads is abraded and even the threads are blocked easily due to large torque is avoided, limitation of operation space is avoided, in addition, the situation that the tensioner is assembled and disassembled on an operation site can be avoided, and then the bolt screwing efficiency is improved.

Description

Technical Field

[0001] This application relates to the technical field of bolt disassembly and assembly, and particularly to a semi-automatic hydraulic tensioner. Background Art

[0002] As a core component of mechanical connections, bolts are widely used in high-pressure, high-temperature, and high-load working conditions in fields such as energy equipment, heavy machinery, aerospace, and rail transit. Traditional bolt disassembly and assembly technologies mainly rely on torque wrenches or hydraulic wrenches to generate axial pre-tightening force between the nut and the bolt by applying a rotational torque. However, such methods have significant limitations: First, the control accuracy of the bolt axial pre-tightening force is greatly affected by factors such as the thread friction coefficient and lubrication conditions, easily resulting in a large deviation in the pre-tightening force; Second, when disassembling and assembling large-sized bolts, an extremely high torque is required, resulting in a large volume of the tool and limited operating space; Third, repeatedly applying torque easily causes wear on the thread surface or even thread jamming, affecting the reusability. Summary of the Invention

[0003] Embodiments of this application provide a semi-automatic hydraulic tensioner to improve the control accuracy of bolt pre-tightening force without being restricted by the operating space, and to avoid the situation where large torque easily causes wear on the thread surface or even thread jamming.

[0004] Embodiments of this application provide a semi-automatic hydraulic tensioner, including: a hydraulic cylinder, a pull rod, and a support sleeve;

[0005] The hydraulic cylinder includes a piston and a housing. One end of the pull rod abuts against the end of the piston in the axial direction and can rotate relative to the piston, and the other end is provided with connection threads for connecting the target screw.

[0006] The support sleeve is rotatably connected to the housing, and a slidable wrench assembly is arranged inside the support sleeve to drive the target nut to rotate when the wrench assembly slides to the working position where it meshes with the target nut.

[0007] In one implementation, the semi-automatic hydraulic tensioner further includes a lock nut; the lock nut is screwed onto the pull rod, and one end of the lock nut abuts against the piston;

[0008] An annular step is provided on the outer wall of the lock nut, and an elastic reset device is arranged between the annular step and the housing to reset the piston after the piston is depressurized.

[0009] In one implementation, the elastic reset device includes a mounting seat and a first elastic member;

[0010] The mounting seat is fixedly connected to the housing, the first elastic member is arranged inside the mounting seat, and one end abuts against the annular step.

[0011] In one implementation, the first elastic member includes an upper disc spring and a lower disc spring;

[0012] Wherein, the upper disc spring is fitted and mounted, and the opening of the upper disc spring faces the mounting seat; the lower disc spring is fitted to the annular step, and the opening of the lower disc spring faces the annular step.

[0013] In one implementation, the pull rod includes a first end portion and a second end portion with variable diameters, and the radial dimension of the first end portion is smaller than that of the second end portion;

[0014] A variable-diameter transition section is provided between the first end portion and the second end portion, and one end of the piston away from the locking nut abuts against the variable-diameter transition section.

[0015] In one implementation, the semi-automatic hydraulic tensioner further includes a guide sleeve disposed inside the housing, and the outer periphery of the second end portion is slidably fitted to the inner wall of the guide sleeve.

[0016] In one implementation, the semi-automatic hydraulic tensioner further includes a connecting pin. A connecting hole is provided on the housing, and an annular card slot is provided on the guide sleeve. The connecting pin passes through the connecting hole and is snapped into the annular card slot.

[0017] In one implementation, the wrench assembly includes a second elastic member and a clamping body for connecting and rotating a target nut;

[0018] One end of the second elastic member is fixed to the end of the housing, and the other end is connected to the clamping body; a convex platform for restricting the free end of the clamping body is provided on the support sleeve.

[0019] In one implementation, a gear groove is provided on the outer circle of the semi-clamping body, a gear set meshing with the gear groove is provided on the housing, and a power interface is provided at the power input end of the gear set.

[0020] In one implementation, an avoidance surface for avoiding a solid wall structure is provided on the outer periphery of the support sleeve, and an observation port for observing the rotation state of the target nut is provided.

[0021] The embodiment of the present application provides a semi-automatic hydraulic tensioner. By designing the hydraulic cylinder, the pull rod and the support sleeve as an integral structure, when it is necessary to stretch a bolt, the pull rod can be directly connected to the target screw, and when the wrench assembly slides to the working position meshing with the target nut, the target nut can be driven to rotate, directly realizing the tightening or loosening of the target nut. During disassembly, it is only necessary to disconnect the connection between the pull rod and the target screw, thereby ensuring the pre-tightening force control accuracy. Moreover, after the target screw is stretched, it is possible to avoid rotating the target nut under a small torque, avoiding the situation that large torque is likely to cause wear on the thread surface or even thread jamming, and being not restricted by the operating space. In addition, it is possible to avoid assembling or disassembling the tensioner on-site during operation, thereby improving the bolt screwing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solution of this application, the following will briefly introduce the attached drawings required in the embodiments. Obviously, for those of ordinary skill in the art, without creative efforts, other attached drawings can also be obtained based on these attached drawings.

[0023] Figure 1 Schematic diagram of the overall structure of a semi-automatic hydraulic tensioner provided by an embodiment of this application Figure 1 ;

[0024] Figure 2 Schematic diagram of the partial structure of a semi-automatic hydraulic tensioner provided by an embodiment of this application Figure 1 ;

[0025] Figure 3 Schematic diagram of the structure of the lock nut provided by an embodiment of this application;

[0026] Figure 4 Schematic diagram of the structure of the pull rod provided by an embodiment of this application;

[0027] Figure 5 Schematic diagram of the partial structure of a semi-automatic hydraulic tensioner provided by an embodiment of this application Figure 2 ;

[0028] Figure 6 Schematic diagram of the partial structure of a semi-automatic hydraulic tensioner provided by an embodiment of this application Figure 3 ;

[0029] Figure 7 Schematic diagram of the partial structure of the support sleeve provided by an embodiment of this application Figure 1 ;

[0030] Figure 8 Schematic diagram of the partial structure of the support sleeve provided by an embodiment of this application Figure 2 .

[0031] Wherein: 1 - hydraulic cylinder, 101 - piston, 102 - housing, 103 - connection hole, 104 - carrying handle, 105 - hydraulic oil pipeline, 2 - pull rod, 201 - first end, 202 - second end, 203 - stepped transition section, 204 - ratchet interface, 3 - support sleeve, 302 - observation port, 303 - relief surface, 4 - wrench assembly, 401 - second elastic member, 402 - clamping body, 5 - lock nut, 501 - annular step, 6 - elastic reset device, 601 - mounting seat, 602 - first elastic member, 7 - guide sleeve, 701 - annular groove, 8 - connecting pin, 9 - gear set, 10 - power interface, 100 - target screw, 200 - target nut, 300 - solid wall, 400 - hydraulic pump. Detailed implementation manners

[0032] In the prior art, in order to realize the screwing of bolts, an assembled hydraulic tensioner is adopted. During use, the hydraulic tensioner injects hydraulic oil into the oil cylinder through an ultra-high pressure pump station, thereby pushing the piston to apply a pure axial tension to the bolt, causing the bolt to undergo elastic elongation. When the axial elongation of the bolt reaches a predetermined value, the nut can be rotated to the mating surface with zero resistance, and after pressure relief, the bolt elastically contracts to form a precise pre-tightening force.

[0033] However, the existing hydraulic tensioners are of a split structure. During use, components such as a barrel wrench, a support sleeve, a hydraulic jack, and a tension head need to be assembled or disassembled in sequence. Taking the tensioner used for an M90 bolt as an example, the overall weight of the tensioner is relatively large, generally more than 35 KG, and the assembly and disassembly processes are extremely inconvenient.

[0034] An embodiment of the present application provides a semi-automatic hydraulic tensioner, as Figure 1 shown. The semi-automatic hydraulic tensioner includes: a hydraulic cylinder 1, a pull rod 2, and a support sleeve 3; wherein, the hydraulic cylinder 1 includes a piston 101 and a housing 102. One end of the pull rod 2 abuts against the end of the piston 101 in the axial direction and can rotate relative to the piston 101, and the other end is provided with a connecting thread for connecting the target screw 100; the support sleeve 3 is rotatably connected to the housing 102, and a slidable wrench assembly 4 is arranged inside the support sleeve 3 to drive the target nut 200 to rotate when the wrench assembly 4 slides to the working position meshing with the target nut 200.

[0035] During actual use, only the pull rod 2 needs to be aligned and connected along the axis of the target screw 100, and then the target screw can be directly stretched without on-site assembly or disassembly of the semi-automatic hydraulic tensioner.

[0036] It should be noted that during actual application, the semi-automatic hydraulic tensioner is provided with hydraulic power by a hydraulic pump 400. When multiple bolts need to be stretched simultaneously, one hydraulic pump 400 can be used to drive multiple groups of hydraulic tensioners to implement simultaneously.

[0037] Taking a standard bolt screw as an example, when loosening the target nut, the operation steps are as follows:

[0038] First, align and straighten the pull rod 2 along the axis of the target screw 100, and rotate the pull rod 2 clockwise to connect the connecting thread of the pull rod 2 with the target screw 100 until the distance between the support sleeve 3 and the mounting surface of the target nut 200 reaches a preset distance. For example, the preset distance is 2 - 3 mm.

[0039] Then, pressurize the piston 101 to the required pressure by using the hydraulic cylinder 1, thereby driving the pull rod 2 to move through the piston 101 to stretch the target screw 100 through the pull rod 2. Among them, the transmission process of the acting force is: hydraulic oil → piston 101 → pull rod 2 → target screw 100.

[0040] Then, when the wrench assembly 4 slides to the working position where it meshes with the target nut 200, the target nut 200 is driven to rotate by the wrench assembly 4, so that the target nut 200 is loosened.

[0041] Then, the hydraulic cylinder 1 is depressurized, the pull rod 2 elastically retracts along with the target screw rod 100, and the wrench assembly 4 automatically resets and disengages from the working position where it meshes with the target nut 200.

[0042] Finally, the pull rod 2 is rotated counterclockwise to disconnect the pull rod 2 from the target screw rod 100, thereby completing the loosening operation of the target nut 200.

[0043] Taking a standard bolt and screw rod as an example, when tightening the target nut:

[0044] First, align and straighten the pull rod 2 along the axis of the target screw rod 100, and rotate the pull rod 2 clockwise to thread-connect the connection thread of the pull rod 2 with the target screw rod 100 until the support sleeve 3 is in close contact with the mounting surface of the target nut 200.

[0045] Then, the piston 101 is pressurized to the required pressure by the hydraulic cylinder 1, so as to drive the pull rod 2 to move through the piston 101, and the target screw rod 100 is stretched through the pull rod 2. Among them, the force transmission process is: hydraulic oil → piston 101 → pull rod 2 → target screw rod 100.

[0046] Then, when the wrench assembly 4 slides to the working position where it meshes with the target nut 200, the target nut 200 is driven to rotate by the wrench assembly 4, so that the target nut 200 is tightened.

[0047] Then, the hydraulic cylinder 1 is depressurized, the pull rod 2 elastically retracts along with the target screw rod 100, and the wrench assembly 4 automatically resets and disengages from the working position where it meshes with the target nut 200.

[0048] Finally, the pull rod 2 is rotated counterclockwise to disconnect the pull rod 2 from the target screw rod 100, thereby completing the tightening operation of the target nut 200.

[0049] It should be noted that the piston 101 provided in the embodiment of the present application is powered by a hydraulic pump 400. As Figure 1 shown, a hydraulic oil pipeline 105 is provided on the housing 102, and the power chamber of the hydraulic pump 400 is connected to the chamber where the piston 101 is located through the hydraulic oil pipeline 105.

[0050] The embodiment of the present application provides a semi-automatic hydraulic tensioner. By designing the hydraulic cylinder 1, the pull rod 2, and the support sleeve 3 as an integral structure, when it is necessary to stretch a bolt, the pull rod 2 can be directly connected to the target screw 100. When the wrench assembly 4 slides to the working position where it meshes with the target nut 200, the target nut 200 is driven to rotate, directly realizing the tightening or loosening of the target nut 200. During disassembly, it is only necessary to disconnect the connection between the pull rod 2 and the target screw 100, thereby ensuring the pre-tightening force control accuracy. Moreover, after the target screw 100 is stretched, it is possible to avoid rotating the target nut 200 under a small torque, preventing the situation where large torque is likely to cause wear on the thread surface or even thread jamming, and it is not restricted by the operating space. In addition, it is possible to avoid assembling or disassembling the tensioner on-site, thereby improving the bolt screwing efficiency.

[0051] The existing tensioner is formed by assembling multiple components. Among them, after the oil cylinder is depressurized, the piston cannot automatically return to its original position, and the operator needs to strike the pull rod to drive the piston to return to its original position. Prolonged striking is likely to cause the piston or the oil cylinder to be scored and damaged, resulting in high maintenance costs. In view of the above technical problems, as Figure 2 shown, in some embodiments of the present application, the semi-automatic hydraulic tensioner further includes a locking nut 5; the locking nut 5 is screwed onto the pull rod 2, and the end of the locking nut 5 abuts against the piston 101. In order to enable the locking nut 5 to move synchronously with the pull rod 2, the locking nut and the pull rod 2 can also be fixedly connected by a pin. Among them, as Figure 3 shown, an annular step 501 is provided on the outer wall of the locking nut 5, and an elastic reset device 6 is provided between the annular step 501 and the housing 102 to reset the piston 101 through the elastic reset device 6 after the piston 101 is depressurized.

[0052] As Figure 2 shown, the elastic reset device 6 includes a mounting seat 601 and a first elastic member 602; among them, the mounting seat 601 is fixedly connected to the housing 102, for example, by screw connection. The first elastic member 602 is disposed in the mounting seat 601 and abuts against the annular step 501 at one end, that is, the first elastic member 602 is disposed between the mounting seat 601 and the annular step 501. In this way, when the piston 101 is depressurized, the first elastic member 602 pushes the locking nut 5 to reset through the annular step 501, ensuring that the pull rod 2 and the target screw 100 retract synchronously and avoiding an empty stroke of the pull rod 2. This design not only improves the reset stability of the pull rod 2, but also with the modular design method, the mounting seat 601 is detachable, facilitating the replacement or adjustment of the number of disc springs to adapt to different working conditions, and can simplify the maintenance process of the hydraulic tensioner and reduce the maintenance costs during long-term use.

[0053] Further, the first elastic member 602 includes an upper disc spring and a lower disc spring; wherein, the upper disc spring is fitted to the mounting seat 601, and the opening of the upper disc spring faces the mounting seat 601; the lower disc spring is fitted to the annular step 501, and the opening of the lower disc spring faces the annular step 501. In this way, the upper disc spring and the lower disc spring are alternately stacked to provide uniform elastic force, forming an efficient elastic buffer system to ensure that the piston 101 is smoothly reset instantly during pressure relief. In addition, the disc spring group arranged up and down can withstand high compressive force and is suitable for the disassembly and assembly of high-torque bolts; the alternately opening directions avoid the misalignment of the disc springs, and thus an anti-jamming design is adopted to ensure the reliability of elastic reset.

[0054] As Figure 4 shown, the pull rod 2 includes a first end portion 201 and a second end portion 202 with variable diameters, and the radial dimension of the first end portion 201 is smaller than that of the second end portion 202; a variable-diameter transition section 203 is arranged between the first end portion 201 and the second end portion 202. Among them, the first end portion 201 is a solid structure, the second end portion 202 is a hollow structure, and connecting threads are arranged on the inner wall of the hollow structure.

[0055] Wherein, one end of the piston 101 away from the locking nut 5 abuts against the variable-diameter transition section 203. In this way, by abutting the piston 101 against the variable-diameter transition section 203, under the double restrictions of the locking nut 5 and the pull rod 2, the large idle stroke of the piston 101 is prevented.

[0056] As Figure 5 shown, in some embodiments of the present application, the semi-automatic hydraulic tensioner further includes a guide sleeve 7 and a connecting pin 8 arranged inside the housing 102, and the outer periphery of the second end portion 202 is slidably fitted with the inner wall of the guide sleeve 7. As Figure 1 and Figure 5 shown, a connecting hole 103 is arranged on the housing 102. As Figure 5 shown, an annular clamping groove 701 is arranged on the guide sleeve 7, and the connecting pin 8 passes through the connecting hole 103 and is clamped into the annular clamping groove 701, that is, the length of the connecting pin 8 needs to meet the requirement that after the connecting pin 8 is inserted, it is embedded inside the annular clamping groove 701, but the end of the connecting pin 8 does not tightly abut against the bottom of the annular clamping groove 701, so as to realize the mutual free rotation between the housing 102 and the support sleeve 3, that is, the support sleeve 3 is rotatably connected to the housing 102.

[0057] Among them, the inner wall of the guide sleeve 7 is smooth to ensure the smooth movement of the pull rod 2 and reduce the frictional loss; the end of the connecting pin 8 can adopt a limit flange design to prevent accidental detachment and improve the reliability of the device. Fixed by the annular clamping groove 701, the guide sleeve 7 has no displacement in the axial direction, ensuring the accurate guiding of the pull rod 2 and extending the service life. As Figure 6As shown, in some embodiments of the present application, the wrench assembly 4 includes a second elastic member 401, and a clamping body 402 for connecting and rotating the target nut 200; the second elastic member 401 is fixed in the support sleeve 3 through a spring seat 403, one end of the second elastic member 401 is connected to the end of the housing 102, and the other end is connected to the clamping body 402. In the actual application process, the clamping body 402 is a wrench structure whose inner ring matches the outer ring of the target nut 200. In this way, the second elastic member 401 always presses the clamping body 402, so that the clamping body 402 and the target nut 200 automatically engage with each other and prevent the clamping body 402 from moving. In addition, a boss 301 is provided on the support sleeve 3 to limit the free end of the clamping body 402, so as to ensure that the clamping body 402 does not separate from the support sleeve 3 during operation.

[0058] When tightening and removing bolts, the existing tensioner needs to insert the lever into the socket wrench hole to move the nut. Due to the limited width of the bottom opening of the support sleeve, the lever can only move 1 / 10 to 1 / 8 of the nut each time, which is inefficient. Figure 6 As shown, in some embodiments of the present application, the outer ring of the card body 402 is provided with a gear groove, the housing 102 is provided with a gear set 9 meshing with the gear groove, and the power input end of the gear set 9 is provided with a power interface 902. For example, the power interface 10 is connected to a ratchet wrench to achieve continuous rotation of the card body 402 in the forward and reverse directions, and the manpower requirement can be reduced by optimizing the transmission ratio of the gear set 9.

[0059] In actual application, Figure 1 As shown, if the target screw 100 is set at a position close to the solid wall 300, for example, the solid wall 300 is a rib or a wall, and this bolt is partially close to the wall surface such as the rib, and the bolt cannot be installed with a conventional hydraulic tensioner due to the small space. In this regard, in the embodiment of the present application, the support sleeve 3 and the housing 102 are in a flexible connection to achieve rapid adjustment of the connection position of the gear set 9 on the support sleeve 3 to prevent interference with the solid side wall and failure to work. In addition, the outer periphery of the support sleeve 3 is provided with an avoidance surface 302 for avoiding the solid wall structure, and an observation port for observing the rotation state of the target nut 200 is provided.

[0060] Specifically, Figure 8 As shown, the support sleeve 3 is designed in a cylindrical shape, and the outer wall surface of 1 / 6-1 / 5 of the total circumference of the support sleeve 3 is machined and thinned into a plane to form an avoidance surface 302, thereby avoiding the solid wall of the Linji bolt. For example, the thinnest part of the plane is about 2mm to prevent interference with the solid side wall surface, and an opening is processed near the bottom of the avoidance surface 302 to form an observation port, so that the operator can observe the rotation state of the target nut 200, wherein the opening length of the observation port is consistent with the width of the avoidance surface 302, and the height is based on the consideration of the target nut 200.

[0061] In addition, for the convenience of rotating the pull rod 2, as Figure 1 shown, in some embodiments of the present application, a ratchet interface 204 may further be provided at the top of the pull rod 2. In this way, an electric wrench can be connected through the ratchet interface 204, so as to realize the quick screwing-in or screwing-out of the pull rod 2 into or from the target screw rod 100.

[0062] In addition, for the convenience of carrying the semi-automatic hydraulic stretcher and removing the semi-automatic hydraulic stretcher from the bolt station, as Figure 1 shown, the housing 102 is further provided with a handle strap 104 to facilitate grasping the semi-automatic hydraulic stretcher.

[0063] The embodiment of the present application provides a semi-automatic hydraulic stretcher. By designing the hydraulic cylinder 1, the pull rod 2 and the support sleeve 3 as an integral structure, when it is necessary to stretch a bolt, the pull rod 2 can be directly connected to the target screw rod 100, and when the wrench assembly 4 slides to the working position where it meshes with the target nut 200, the target nut 200 is driven to rotate, directly realizing the tightening or loosening of the target nut 200. During disassembly, it is only necessary to disconnect the connection between the pull rod 2 and the target screw rod 100, thereby ensuring the pre-tightening force control accuracy. And after the target screw rod 100 is stretched, it is possible to avoid rotating the target nut 200 under a small torque, avoiding the situation that large torque is likely to cause wear on the thread surface or even thread jamming, and being not limited by the operation space. In addition, it is possible to avoid assembling or disassembling the stretcher on-site at the operation site, thereby improving the bolt screwing efficiency.

[0064] The above specific embodiments have further elaborated on the purpose, technical solution and beneficial effects of the present application. It should be understood that the above are only specific embodiments of the present application and are not used to limit the protection scope of the present application. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solution of the present application shall be included in the protection scope of the present application.

Claims

1. A semi-automatic hydraulic tensioner, characterized in that, Comprising: A hydraulic cylinder (1), a pull rod (2) and a support sleeve (3); The hydraulic cylinder (1) includes a piston (101) and a housing (102). One end of the pull rod (2) abuts against the end of the piston (101) in the axial direction and can rotate relative to the piston (101), and the other end is provided with a connecting thread for connecting the target screw (100); The support sleeve (3) is rotatably connected to the housing (102), and a slidable wrench assembly (4) is arranged inside the support sleeve (3) to drive the target nut (200) to rotate when the wrench assembly (4) slides to the working position where it meshes with the target nut (200).

2. A semi-automatic hydraulic tensioner according to claim 1, characterized in that, It further includes a lock nut (5); the lock nut (5) is screwed onto the pull rod (2), and one end of the lock nut (5) abuts against the piston (101); An annular step (501) is arranged on the outer wall of the lock nut (5), and an elastic reset device (6) is arranged between the annular step (501) and the housing (102) to reset the piston (101) after the piston (101) is depressurized.

3. A semi-automatic hydraulic stretcher according to claim 2, characterized in that, The elastic reset device (6) includes a mounting seat (601) and a first elastic member (602); The mounting seat (601) is fixedly connected to the housing (102), the first elastic member (602) is arranged inside the mounting seat (601), and one end abuts against the annular step (501).

4. A semi-automatic hydraulic tensioner according to claim 3, characterized in that, The first elastic member (602) includes an upper disc spring and a lower disc spring; Wherein, the upper disc spring is arranged in contact with the mounting seat (601), and the opening of the upper disc spring faces the mounting seat (601); the lower disc spring is arranged in contact with the annular step (501), and the opening of the lower disc spring faces the annular step (501).

5. A semi-automatic hydraulic tensioner according to claim 2, characterized in that, The pull rod (2) includes a first end portion (201) and a second end portion (202) with a variable diameter setting, and the radial dimension of the first end portion (201) is smaller than that of the second end portion (202); A variable diameter transition section (203) is arranged between the first end portion (201) and the second end portion (202), and one end of the piston (101) away from the lock nut (5) abuts against the variable diameter transition section (203).

6. A semi-automatic hydraulic stretcher according to claim 5, characterized in that, It further includes a guide sleeve (7) arranged inside the housing (102), and the outer periphery of the second end portion (202) is in sliding fit with the inner wall of the guide sleeve (7).

7. A semi-automatic hydraulic stretcher according to claim 6, characterized in that, It further includes a connecting pin (8), a connecting hole (103) is arranged on the housing (102), an annular card slot (701) is arranged on the guide sleeve (7), and the connecting pin (8) passes through the connecting hole (103) and is snapped into the annular card slot (701).

8. A semi-automatic hydraulic stretcher according to claim 1, characterized in that, The wrench assembly (4) includes a second elastic member (401) and a clamping body (402) for connecting and rotating the target nut (200); One end of the second elastic member (401) is fixed to the end of the housing (102), and the other end is connected to the clamping body (402); a convex platform (301) for restricting the free end of the clamping body (402) is arranged on the support sleeve (3).

9. A semi-automatic hydraulic stretcher according to claim 8, characterized in that, A gear groove is arranged on the outer ring of the clamping body (402), a gear set (9) meshing with the gear groove is arranged on the housing (102), and a power interface (10) is arranged at the power input end of the gear set (9).

10. A semi-automatic hydraulic stretcher according to claim 1, characterized in that, The outer periphery of the support sleeve (3) is provided with an avoidance surface (302) for avoiding the solid wall structure, and an observation port for observing the rotation state of the target nut (200).

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