Semi-automatic hydraulic stretcher

Abstract

The application relates to the field of climbing operation vehicles, and provides a kind of semi-automatic hydraulic stretcher, by the hydraulic cylinder, pull rod and support sleeve are designed as integral structure, when the bolt needs to be stretched, the pull rod can be directly connected with the target screw, and when the wrench assembly slides to the working position engaged with the target nut, the target nut is driven to rotate, the tightening or loosening of the target nut is directly realized, when disassembling, the connection between the pull rod and the target screw needs to be disconnected, so that the pretightening force control precision is guaranteed, and after the target screw is stretched, the rotation of the target nut can be realized under the condition of small torque, the wear of the thread surface caused by large torque is avoided, even the situation that the thread is stuck, and the operation space is not limited, in addition, the disassembly and stretching of the stretcher can be avoided in the operation site, and the bolt screwing efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of bolt assembly and disassembly technology, and in particular to a semi-automatic hydraulic tensioner. Background Technology

[0002] Bolts, as core components of mechanical connections, are widely used in high-pressure, high-temperature, and high-load conditions in energy equipment, heavy machinery, aerospace, and rail transportation. Traditional bolt assembly and disassembly techniques mainly rely on torque wrenches or hydraulic wrenches to apply rotational torque to generate axial preload between the nut and bolt. However, this method has significant limitations: firstly, the control accuracy of the bolt's axial preload is greatly affected by factors such as the thread friction coefficient and lubrication conditions, easily leading to large preload deviations; secondly, disassembling and assembling large-size bolts requires extremely high torque, resulting in bulky tools and limited operating space; and thirdly, repeated application of torque can easily cause thread surface wear or even thread jamming, affecting reusability. Utility Model Content

[0003] This application provides a semi-automatic hydraulic tensioner to improve the accuracy of bolt preload control without being limited by operating space, and to address the issue that high torque can easily cause thread surface wear or even thread jamming.

[0004] This embodiment provides a semi-automatic hydraulic tensioner, including: a hydraulic cylinder, a tie rod, and a support sleeve;

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

[0006] The support sleeve has a rotatable connecting housing, and the support sleeve is provided with a sliding wrench assembly to drive the target nut to rotate when the wrench assembly slides to the working position where it engages with the target nut.

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

[0008] The outer wall of the locking nut is provided with an annular step, and an elastic reset device is provided 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 base and a first elastic element;

[0010] The mounting base is fixedly connected to the housing, and the first elastic element is disposed inside the mounting base, with one end abutting against the annular step.

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

[0012] The upper disc spring is fitted to the mounting base, with its opening facing the mounting base; the lower disc spring is fitted to the annular step, with its opening facing the annular step.

[0013] In one implementation, the tie rod includes a first end and a second end with a variable diameter, wherein the radial dimension of the first end is smaller than the radial dimension of the second end;

[0014] A variable diameter transition section is provided between the first end and the second end, and the 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, with the outer periphery of the second end slidingly fitted against the inner wall of the guide sleeve.

[0016] In one implementation, the semi-automatic hydraulic tensioner also includes a connecting pin, a connecting hole on the housing, and an annular groove on the guide sleeve, wherein the connecting pin passes through the connecting hole and engages with the annular groove.

[0017] In one implementation, the wrench assembly includes a second elastic element and a snap-fit ​​body for engaging and rotating a target nut;

[0018] One end of the second elastic element is fixed to the end of the housing, and the other end is connected to the snap-fit ​​body; the support sleeve is provided with a boss that restricts the free end of the snap-fit ​​body.

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

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

[0021] This application provides a semi-automatic hydraulic tensioner. By designing the hydraulic cylinder, pull rod, and support sleeve as an integral structure, when bolts need to be stretched, the pull rod can be directly connected to the target screw. When the wrench assembly slides to the working position where it engages with the target nut, it drives the target nut to rotate, directly tightening or loosening the target nut. During disassembly, the connection between the pull rod and the target screw needs to be disconnected, thus ensuring the accuracy of preload control. After the target screw is stretched, it avoids rotating the target nut with a small torque, avoiding the possibility of thread surface wear or even thread jamming caused by large torque. It is not limited by operating space and avoids the need to assemble and disassemble the tensioner at the operation site, thereby improving bolt tightening efficiency. Attached Figure Description

[0022] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the overall structure of a semi-automatic hydraulic tensioner provided in this application embodiment. Figure 1 ;

[0024] Figure 2 A partial structural diagram of a semi-automatic hydraulic tensioner provided in this application embodiment. Figure 1 ;

[0025] Figure 3 This is a schematic diagram of the structure of the locking nut provided in the embodiments of this application;

[0026] Figure 4 This is a schematic diagram of the structure of the tie rod provided in an embodiment of this application;

[0027] Figure 5 A partial structural diagram of a semi-automatic hydraulic tensioner provided in this application embodiment. Figure 2 ;

[0028] Figure 6 A partial structural diagram of a semi-automatic hydraulic tensioner provided in this application embodiment. Figure 3 ;

[0029] Figure 7 A partial structural diagram of the support sleeve provided in the embodiments of this application. Figure 1 ;

[0030] Figure 8 A partial structural diagram of the support sleeve provided in the embodiments of this application. Figure 2 .

[0031] Wherein: 1-Hydraulic cylinder, 101-Piston, 102-Housing, 103-Connecting hole, 104-Handle strap, 105-Hydraulic oil line, 2-Pull rod, 201-First end, 202-Second end, 203-Diameter transition section, 204-Ratchet interface, 3-Support sleeve, 302-Observation port, 303-Allowing surface, 4-Wrench assembly, 401-Second elastic element, 402-Snap-fit ​​body, 5-Locking nut, 501-Annular step, 6-Elastic reset device, 601-Mounting base, 602-First elastic element, 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

[0032] In existing technologies, a modular hydraulic tensioner is used to tighten bolts. During operation, the hydraulic tensioner injects hydraulic oil into the cylinder via an ultra-high pressure pump station, thereby pushing the piston to apply a pure axial tensile force to the bolt, causing the bolt to elastically elongate. When the bolt's axial elongation reaches a predetermined value, the nut can be rotated to the mating surface with zero resistance. After pressure is released, the bolt elastically contracts, thus forming a precise preload.

[0033] However, existing hydraulic tensioners are modular in structure. When using them, it is necessary to assemble or disassemble components such as the sleeve wrench, support sleeve, hydraulic jack, and tensioning head in sequence. Taking the tensioner used for M90 bolts as an example, the overall weight of the tensioner is relatively large, generally more than 35KG, making the assembly and disassembly process extremely inconvenient.

[0034] This application provides a semi-automatic hydraulic tensioner, such as... Figure 1 As 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 to the target screw 100; the support sleeve 3 is rotatably connected to the housing 102, and a slidable wrench assembly 4 is provided inside the support sleeve 3 to drive the target nut 200 to rotate when the wrench assembly 4 slides to the working position of engaging with the target nut 200.

[0035] In actual use, simply align and connect the pull rod 2 along the axis of the target screw 100 to directly stretch the target screw without needing to disassemble the semi-automatic hydraulic tensioner on-site.

[0036] It should be noted that in practical applications, the semi-automatic hydraulic tensioner is powered by the hydraulic pump 400. When multiple bolts need to be tensioned at the same time, one hydraulic pump 400 can drive multiple sets of hydraulic tensioners to perform the work simultaneously.

[0037] Taking a standard bolt as an example, the operating steps for loosening the target nut 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 make the pull rod 2 and the target screw 100 connected by thread until the distance between the support sleeve 3 and the mounting surface of the target nut 200 reaches the preset distance, for example, the preset distance is 2 to 3 mm.

[0039] Then, the hydraulic cylinder 1 pressurizes the piston 101 to the required pressure, thereby driving the pull rod 2 to move, so as to stretch the target screw 100 through the pull rod 2. The force transmission process 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 engages with the target nut 200, the target nut 200 is rotated by the wrench assembly 4, thereby loosening the target nut 200.

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

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

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

[0044] First, align and straighten the pull rod 2 along the axis of the target screw 100, and rotate the pull rod 2 clockwise to make the threaded connection between the pull rod 2 and the target screw 100 until the support sleeve 3 is tightly attached to the mounting surface of the target nut 200.

[0045] Then, the hydraulic cylinder 1 pressurizes the piston 101 to the required pressure, thereby driving the pull rod 2 to move, so as to stretch the target screw 100 through the pull rod 2. The force transmission process is: hydraulic oil → piston 101 → pull rod 2 → target screw 100.

[0046] Then, when the wrench assembly 4 slides to the working position where it engages with the target nut 200, the target nut 200 is rotated by the wrench assembly 4, thereby tightening the target nut 200.

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

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

[0049] It should be noted that the piston 101 provided in this embodiment is powered by a hydraulic pump 400, such as... Figure 1 As shown, a hydraulic oil line 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 line 105.

[0050] This application provides a semi-automatic hydraulic tensioner. By designing the hydraulic cylinder 1, pull rod 2, and support sleeve 3 as an integral structure, when bolts need to be stretched, 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 engages with the target nut 200, it drives the target nut 200 to rotate, directly tightening or loosening the target nut 200. During disassembly, the connection between the pull rod 2 and the target screw 100 needs to be disconnected, thus ensuring the accuracy of preload control. After the target screw 100 is stretched, the rotation of the target nut 200 can be avoided with a small torque, preventing the thread surface from wearing or even jamming due to large torque. It is not limited by operating space and can avoid assembling and disassembling the tensioner at the operation site, thereby improving bolt tightening efficiency.

[0051] Existing tensioners are assembled from multiple components. In one case, after the hydraulic cylinder is depressurized, the piston cannot automatically return to its original position. An operator must tap the connecting rod to force the piston back to its original position. Prolonged tapping can easily cause scratches and damage to the piston or hydraulic cylinder, resulting in high maintenance costs. To address these technical problems, such as... Figure 2 As shown in some embodiments of this application, the semi-automatic hydraulic tensioner also 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. 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. Wherein, as... Figure 3 As shown, the outer wall of the locking nut 5 is provided with an annular step 501, and an elastic reset device 6 is provided between the annular step 501 and the housing 102, so that after the piston 101 is depressurized, the piston 101 is reset by the elastic reset device 6.

[0052] like Figure 2 As shown, the elastic reset device 6 includes a mounting base 601 and a first elastic element 602. The mounting base 601 is fixedly connected to the housing 102, for example, by screws. The first elastic element 602 is disposed within the mounting base 601, with one end abutting against the annular step 501, i.e., the first elastic element 602 is positioned between the mounting base 601 and the annular step 501. Thus, when the piston 101 depressurizes, the first elastic element 602 pushes the locking nut 5 to reset via the annular step 501, ensuring that the pull rod 2 retracts synchronously with the target screw 100, preventing the pull rod 2 from having a free stroke. This design not only improves the reset stability of the pull rod 2, but also, through its modular design, allows the mounting base 601 to be detachable, facilitating the replacement or adjustment of the number of disc springs to adapt to different working conditions. Furthermore, it simplifies the maintenance process of the hydraulic tensioner, reducing long-term maintenance costs.

[0053] Furthermore, the first elastic element 602 includes an upper disc spring and a lower disc spring; the upper disc spring is disposed against the mounting base 601, with its opening facing the mounting base 601; the lower disc spring is disposed against the annular step 501, with its opening facing the annular step 501. In this way, the upper and lower disc springs are stacked alternately, providing uniform elastic force and forming a highly efficient elastic buffer system, ensuring that the piston 101 smoothly resets upon pressure relief. In addition, the upper and lower disc spring assemblies can withstand high compressive forces, making them suitable for the disassembly and assembly of high-torque bolts; the alternating opening directions prevent disc spring misalignment, thus employing an anti-jamming design to ensure reliable elastic reset.

[0054] like Figure 4 As shown, the tie rod 2 includes a first end 201 and a second end 202 with a variable diameter. The radial dimension of the first end 201 is smaller than that of the second end 202. A variable diameter transition section 203 is provided between the first end 201 and the second end 202. The first end 201 is a solid structure, and the second end 202 is a hollow structure. The inner wall of the hollow structure is provided with connecting threads.

[0055] In this configuration, the end of piston 101 furthest from locking nut 5 abuts against the variable diameter transition section 203. In this way, by abutting piston 101 against variable diameter transition section 203, and under the bidirectional restriction of locking nut 5 and pull rod 2, large free stroke of piston 101 is prevented.

[0056] like Figure 5 As shown, in some embodiments of this application, the semi-automatic hydraulic tensioner further includes a guide sleeve 7 and a connecting pin 8 disposed inside the housing 102, with the outer periphery of the second end 202 slidingly fitted against the inner wall of the guide sleeve 7. Figure 1 and Figure 5 As shown, the housing 102 is provided with a connection hole 103, such as Figure 5 As shown, the guide sleeve 7 is provided with an annular groove 701. The connecting pin 8 passes through the connecting hole 103 and is inserted into the annular groove 701. That is, the length of the connecting pin 8 must meet the following requirements: after the connecting pin 8 is inserted, it is embedded in the annular groove 701, but the end of the connecting pin 8 is not tightly pressed against the bottom of the annular groove 701, so that the housing 102 and the support sleeve 3 can rotate freely with each other, that is, the support sleeve 3 can rotatably connect to the housing 102.

[0057] The guide sleeve 7 has a smooth inner wall, ensuring smooth movement of the pull rod 2 and reducing frictional loss. The end of the connecting pin 8 can be designed with a limiting flange to prevent accidental detachment and improve the reliability of the device. Fixed by the annular groove 701, the guide sleeve 7 has no displacement in the axial direction, ensuring precise guidance of the pull rod 2 and extending its service life. Figure 6As shown in some embodiments of this application, the wrench assembly 4 includes a second elastic element 401 and a snap-fit ​​body 402 for connecting and rotating the target nut 200. The second elastic element 401 is fixed inside the support sleeve 3 by a spring seat 403. One end of the second elastic element 401 is connected to the end of the housing 102, and the other end is connected to the snap-fit ​​body 402. In actual application, the snap-fit ​​body 402 is a wrench structure in which the inner ring matches the outer ring of the target nut 200. In this way, the second elastic element 401 always presses the snap-fit ​​body 402, realizing that the snap-fit ​​body 402 and the target nut 200 automatically engage with each other, preventing the snap-fit ​​body 402 from moving. In addition, the support sleeve 3 is provided with a boss 301 that restricts the free end of the snap-fit ​​body 402 to ensure that the snap-fit ​​body 402 does not detach from the support sleeve 3 during operation.

[0058] Existing tensioners require a lever inserted into the socket wrench hole to turn the nut during bolt tightening and loosening. However, due to the limited width of the opening at the bottom of the support socket, the lever can only turn the nut 1 / 10 to 1 / 8 turn at a time, resulting in low efficiency. To address this problem... Figure 6 As shown in some embodiments of this application, the outer ring of the snap-fit ​​body 402 is provided with a gear groove, the housing 102 is provided with a gear set 9 with meshing gear grooves, 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 realize continuous rotation of the snap-fit ​​body 402 in both directions, and the manual labor requirement can be reduced by optimizing the transmission ratio of the gear set 9.

[0059] In practical applications, such as Figure 1 As shown, if the target screw 100 is positioned near a solid wall 300, for example, if the solid wall 300 is a rib or a wall, the bolt may be partially located close to the rib or other wall surface, making it impossible to mount a conventional hydraulic tensioner due to the limited space. In this embodiment, the support sleeve 3 and the housing 102 are connected in a swivel joint to allow for quick adjustment of the gear set 9 connection position on the support sleeve 3, preventing interference with the solid sidewall and thus ensuring operation. Furthermore, the outer periphery of the support sleeve 3 is provided with a clearance surface 302 to avoid the solid wall structure, and an observation port is provided to observe the rotation state of the target nut 200.

[0060] Specifically, such as Figure 8 As shown, the support sleeve 3 is a cylindrical design. One-sixth to one-fifth of the outer wall of the support sleeve 3 is machined thin to a flat surface to form a clearance surface 302, thus avoiding the solid wall of the bolt. For example, the thinnest part of this flat surface is about 2mm to prevent interference with the solid side wall. An opening is machined near the bottom of the clearance surface 302 to form an observation port, allowing the operator to easily observe the rotation state of the target nut 200. The length of the observation port is the same as the width of the clearance surface 302, and the height is determined with reference to the target nut 200.

[0061] In addition, to facilitate the rotation of lever 2, such as Figure 1 As shown in some embodiments of this application, a ratchet interface 204 can also be provided on the top of the pull rod 2. In this way, an electric wrench can be connected through the ratchet interface 204 to realize the rapid screwing of the pull rod 2 into or out of the screw rod 100.

[0062] In addition, to facilitate the handling of the semi-automatic hydraulic tensioner, and to facilitate its removal from the bolt station, such as... Figure 1 As shown, the housing 102 is also provided with a carrying strap 104 for easy gripping of the semi-automatic hydraulic tensioner.

[0063] This application provides a semi-automatic hydraulic tensioner. By designing the hydraulic cylinder 1, pull rod 2, and support sleeve 3 as an integral structure, when bolts need to be stretched, 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 engages with the target nut 200, it drives the target nut 200 to rotate, directly tightening or loosening the target nut 200. During disassembly, the connection between the pull rod 2 and the target screw 100 needs to be disconnected, thus ensuring the accuracy of preload control. After the target screw 100 is stretched, the rotation of the target nut 200 can be avoided with a small torque, preventing the thread surface from wearing or even jamming due to large torque. It is not limited by operating space and can avoid assembling and disassembling the tensioner at the operation site, thereby improving bolt tightening efficiency.

[0064] The above specific embodiments further illustrate the purpose, technical solution and beneficial effects of this application. It should be understood that the above are only specific embodiments of this application and are not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of this application should be included within the scope of protection of this application.

Claims

1. A semi-automatic hydraulic tensioner, characterized in that, include: Hydraulic cylinder (1), tie rod (2), and 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). The other end is provided with a connecting thread that can be connected to the target screw (100). The support sleeve (3) is rotatably connected to the housing (102), and a slidable wrench assembly (4) is provided 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 engages with the target nut (200).

2. The semi-automatic hydraulic tensioner according to claim 1, characterized in that, It also includes a locking nut (5); the locking nut (5) is screwed onto the pull rod (2), and one end of the locking nut (5) abuts against the piston (101); The outer wall of the locking nut (5) is provided with an annular step (501), and an elastic reset device (6) is provided 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 tensioner according to claim 2, characterized in that, The elastic reset device (6) includes a mounting base (601) and a first elastic element (602); The mounting base (601) is fixedly connected to the housing (102), and the first elastic element (602) is disposed in the mounting base (601), with one end abutting against the annular step (501).

4. A semi-automatic hydraulic tensioner according to claim 3, characterized in that, The first elastic element (602) includes an upper disc spring and a lower disc spring; The upper disc spring is fitted to the mounting base (601), and the opening of the upper disc spring faces the mounting base (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).

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

6. A semi-automatic hydraulic tensioner according to claim 5, characterized in that, It also includes a guide sleeve (7) disposed inside the housing (102), with the outer periphery of the second end (202) slidingly attached to the inner wall of the guide sleeve (7).

7. A semi-automatic hydraulic tensioner according to claim 6, characterized in that, It also includes a connecting pin (8), a connecting hole (103) on the housing (102), and an annular groove (701) on the guide sleeve (7). The connecting pin (8) passes through the connecting hole (103) and is then inserted into the annular groove (701).

8. A semi-automatic hydraulic tensioner according to claim 1, characterized in that, The wrench assembly (4) includes a second elastic element (401) and a snap-fit ​​body (402) for connecting and rotating the target nut (200); One end of the second elastic element (401) is fixed to the end of the housing (102), and the other end is connected to the snap-fit ​​body (402); the support sleeve (3) is provided with a boss (301) that restricts the free end of the snap-fit ​​body (402).

9. A semi-automatic hydraulic tensioner according to claim 8, characterized in that, The outer ring of the snap-fit ​​body (402) is provided with a gear groove, the housing (102) is provided with a gear set (9) with a meshing gear groove, and the power input end of the gear set (9) is provided with a power interface (10).

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

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