Horizontal hydraulic jack

Abstract

The utility model relates to jack manufacturing technical field especially horizontal hydraulic jack, including frame, hoist arm, drive component, control rod, wire harness, power, control press key assembly and control module. Hoist arm and drive component are installed in frame. When working, hoist arm completes lifting action under the hydraulic pressure drive of drive component. Control rod and frame adopt the design of movable connection to facilitate operator to adjust the working position of equipment flexibly. Power and control press key assembly are integrated on control rod, and wire harness is arranged in the inside of control rod to realize the stable electric connection between drive component and power, control press key assembly. On the control logic, control press key assembly outputs control instruction through signal interaction with control module, and control module will convert the instruction into electric control signal and sends to drive component after receiving the instruction, finally realizes the accurate control to horizontal hydraulic jack.

Description

Technical Field

[0001] This utility model relates to the field of jack manufacturing technology, and in particular to a horizontal hydraulic jack. Background Technology

[0002] In scenarios such as car repair, wilderness rescue, and industrial production, the efficiency and safety of heavy lifting operations directly affect the overall progress of the operation, and horizontal hydraulic jacks have become the mainstream tool choice in these scenarios due to their adaptability.

[0003] From the current industry application perspective, the complete operation of traditional horizontal hydraulic jacks relies entirely on manual operation, exhibiting significant design shortcomings. The specific operating logic is as follows: During lifting, the operator repeatedly presses the manual pump lever, which, through mechanical transmission, drives the manual pump piston in a reciprocating motion. This pressurizes the hydraulic oil and delivers it to the hydraulic cylinder of the lifting arm. The pressure generated by the hydraulic oil pushes the piston rod of the hydraulic cylinder outward, ultimately lifting the lifting arm upward. When lowering is required, the operator manually opens the pressure relief valve, relying on the weight of the lifted load to force the hydraulic oil in the hydraulic cylinder to flow back along the oil circuit, thus slowly lowering the lifting arm.

[0004] In practical applications, traditional horizontal hydraulic jacks have revealed significant drawbacks, specifically: 1) Excessive physical exertion for operators. During the pressing of the lever, operators must continuously overcome the resistance of the hydraulic system and the weight transmitted by the load, which can easily lead to arm muscle fatigue over long periods of operation; 2) Low lifting efficiency, with the lifting speed entirely limited by the rhythm of manual operation, making it unsuitable for scenarios with high requirements for operational efficiency; 3) During the lifting process, even slight changes in the pressure and frequency of pressing will directly alter the hydraulic oil delivery speed, resulting in an unstable lifting rhythm of the boom. This makes it difficult to accurately control the lifting height and exacerbates safety risks, especially when dealing with heavy loads.

[0005] In summary, technical personnel are urgently needed to solve the above problems. Utility Model Content

[0006] The purpose of this utility model is to provide a horizontal hydraulic jack that solves the problems of high physical exertion, low lifting efficiency and inability to flexibly adapt to work requirements caused by the purely manual operation of traditional horizontal hydraulic jacks, as well as insufficient operational stability and accuracy and high safety risks under heavy loads.

[0007] This utility model relates to a horizontal hydraulic jack, including a frame, a lifting arm, a drive component, and a control lever; the lifting arm and the drive component are both mounted on the frame, and the lifting arm performs a lifting action under the driving force from the drive component; the control lever is movably connected to the frame to adjust the overall position of the frame. Furthermore, the horizontal hydraulic jack also includes a wiring harness, power supply, control button assembly, and control module that are compatible with the drive component and / or control lever; the drive component includes a motor, a pump station, and a solenoid valve; the motor drives the pump station to perform outward pushing work, and when the solenoid valve is open, the pump station retracts through oil return; the power supply and control button assembly are integrated on the control lever; the wiring harness is used to realize the electrical connection between the drive component and the power supply and control button assembly, and it passes through the control lever; the control button assembly interacts with the control module through signal exchange, outputting control commands to the control module, and the control module outputs electrical control signals to the drive component based on the control commands, so that the drive component can perform outward pushing work or retracting work.

[0008] As a further improvement to the technical solution of this utility model, the pump station includes a hydraulic pump and a hydraulic cylinder; the motor is connected to the hydraulic pump to drive its operation; the control module outputs an electrical control signal to the motor based on the control command to control the motor to start and stop; the hydraulic pump pressurizes the hydraulic oil and delivers it to the hydraulic cylinder, and the extension and retraction of the hydraulic cylinder provides driving force to the boom to realize its lifting and lowering action.

[0009] As a further improvement to the technical solution of this utility model, the control module has both thread control mode and wireless control mode; in thread control mode, the operator triggers the control button component, and the generated thread control signal is transmitted to the control module via the wiring harness to regulate the motor; in wireless control mode, the control module receives the wireless control signal and regulates the motor.

[0010] As a further improvement to the technical solution of this utility model, the control module includes a wireless signal receiving unit; the wireless control signal is emitted by a mobile terminal or a dedicated remote controller and received by the wireless signal receiving unit.

[0011] As a further improvement to the technical solution of this utility model, the wireless signal receiving unit supports Bluetooth, Wi-Fi or radio frequency signal transmission.

[0012] As a further improvement to the technical solution of this utility model, when the wireless control signal is sent by the mobile terminal, the mobile terminal is equipped with a control APP; the control APP displays the hydraulic cylinder working pressure, lifting height of the boom, and power supply information in real time.

[0013] As a further improvement to the technical solution of this utility model, the drive component also includes an emergency return valve; the emergency return valve is connected in series in the hydraulic circuit between the hydraulic cylinder and the hydraulic pump; when the thread control signal fails and the wireless control mode is unavailable, the emergency return valve is rotated to the emergency descent position, and the hydraulic circuit is depressurized to allow the boom to slowly descend.

[0014] As a further improvement to the technical solution of this utility model, the control lever includes a saddle, a torsion spring, a hinge shaft, a lever body, a locking sleeve, a handle, a limit pin, and an aviation connector; the saddle is hinged to the frame via the hinge shaft; the torsion spring is fitted onto the hinge shaft, with its two ends abutting / connecting to the saddle and the frame respectively, and the saddle is subjected to a restoring torque and tends to maintain its initial posture; the saddle is provided with an insertion protrusion; the insertion protrusion has an installation cavity for inserting the lever body and a limiting notch communicating with the installation cavity; the aviation connector is installed and fixed inside the saddle, and its outer side wall is formed with an anti-deflection protrusion; the lever The lower end of the body is provided with an anti-deflection notch that matches the anti-deflection protrusion; the limiting pin has a built-in limiting notch, which passes through the rod body and the aviation plug in sequence, and is fixed to the aviation plug by an interference fit; the locking sleeve is provided with a necked-back section; the rod body is provided with a limiting structure that matches the necked-back section; the necked-back section is axially penetrated by the rod body, and the locking sleeve is connected to the insertion protrusion through a threaded pair, using the necked-back section and the limiting structure to limit the axial displacement of the rod body; and when the locking sleeve is tightened to contact the limiting structure, the axial position of the rod body is locked; the handle is fixed to the top of the rod body.

[0015] As a further improvement to the technical solution of this utility model, the aviation plug is composed of a conductive component and a housing; the conductive component is used to realize signal communication and / or current transmission between the drive component and the wiring harness; the anti-deflection protrusion is formed on the housing.

[0016] As a further improvement to the technical solution of this utility model, the inner wall of the locking sleeve necking section and the outer wall of the rod are in clearance fit; the limiting structure is a limiting ring; the limiting ring is fitted and fixed to the rod; the outer diameter of the limiting ring is larger than the inner diameter of the necking section to form a radial block; when the necking section abuts against the limiting ring, the axial displacement freedom of the rod is restricted by the blocking of the limiting ring and the limiting of the necking section.

[0017] In practical applications, the horizontal hydraulic jack disclosed in this utility model can achieve at least the following beneficial technical effects, specifically: 1) The hydraulic pump is directly driven by an electric motor, eliminating the need for manual high-intensity mechanical operations and reducing the physical exertion of operators from the source, thus avoiding fatigue caused by prolonged work. Furthermore, the stable and controllable speed of the electric motor allows for efficient driving of the hydraulic pump to deliver hydraulic oil, enabling the crane boom to quickly complete lifting and lowering actions. This is suitable for scenarios requiring high operational efficiency, such as automotive repair, field rescue, and industrial production. 2) The control button assembly and control module form a collaborative signal interaction mechanism, constructing an electronic control system. Specifically, the commands output by the control button assembly are converted into electronic control signals by the control module to precisely regulate the motor's start, stop, and operating status. This, in turn, stabilizes the hydraulic pump's hydraulic oil delivery volume and speed, ensuring a smooth lifting rhythm and precise control of the lifting height. Furthermore, relying on reliable power transmission logic and a precise control system, the horizontal hydraulic jack can effectively adapt to heavy-load operation scenarios, reducing the risk of instability during lifting. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a three-dimensional schematic diagram of the horizontal hydraulic jack disclosed in this utility model.

[0020] Figure 2 This is an exploded schematic diagram of the horizontal hydraulic jack disclosed in this utility model.

[0021] Figure 3 yes Figure 1 The front view.

[0022] Figure 4 yes Figure 3 AA sectional view.

[0023] Figure 5 yes Figure 4 A magnified view of part of I.

[0024] Figure 6 This is a three-dimensional schematic diagram of the pump station in the horizontal hydraulic jack disclosed in this utility model.

[0025] Figure 7 This is a three-dimensional schematic diagram of the saddle in the horizontal hydraulic jack disclosed in this utility model.

[0026] Figure 8 This is a three-dimensional schematic diagram of the rod body of the horizontal hydraulic jack disclosed in this utility model.

[0027] Figure 9 This is a three-dimensional schematic diagram of the locking sleeve in the horizontal hydraulic jack disclosed in this utility model.

[0028] Figure 10 yes Figure 9 The front view.

[0029] Figure 11 yes Figure 10 BB cross-sectional view.

[0030] Figure 12 This is an exploded schematic diagram of the aviation plug in the horizontal hydraulic jack disclosed in this utility model.

[0031] 1-Frame; 2-Lifting boom; 3-Drive component; 31-Motor; 32-Hydraulic pump; 33-Hydraulic cylinder; 4-Control lever; 41-Saddle; 411-Insertion protrusion; 4111-Mounting cavity; 4112-Limit notch; 4113-External thread; 42-Torsion spring; 43-Hinge; 44-Aviation plug; 441-Conduction assembly; 442-Housing; 4421-Anti-deflection protrusion; 45-Lever; 451-Annular groove; 452-Limit notch; 46-Locking sleeve; 461-Necked grip section; 462-Internal thread; 47-Handle; 48-Limit pin; 49-Limit ring; 5-Power supply; 6-Control button. Detailed Implementation

[0032] The technical solution of this utility model will be further described in detail below with reference to specific embodiments and accompanying drawings. Figure 1 , Figure 2 The diagrams show a perspective view and an exploded view of the horizontal hydraulic jack disclosed in this utility model. It can be seen that the horizontal hydraulic jack is mainly assembled from several parts, including a frame 1, a lifting arm 2, a drive component 3, and a control lever 4. The lifting arm 2, as the key structure directly bearing the heavy object and performing the lifting action, is installed with the frame 1 as the mounting base and forms a transmission connection with the frame 1. During operation, the lifting arm 2 receives the driving force output from the drive component 3, and relies on the hydraulic transmission principle to achieve uniform and stable lifting and lowering movements, thereby completing the lifting and support operations for the heavy object. The control lever 4 is designed with a movable connection to the frame 1. The operator can flexibly adjust the placement position and tilt angle of the frame 1 on the ground by pushing or rotating the control lever 4, ensuring that the jack can be accurately moved to the preset support point under the heavy object.

[0033] Depend on Figure 1 , Figure 2 As can be clearly seen in the diagram, the horizontal hydraulic jack also includes a wiring harness (not shown in the diagram), a power supply 5, a control button assembly 6, and a control module (not shown in the diagram). The power supply 5 and the control button assembly 6 are both integrated into the control lever 4; the wiring harness is used to establish electrical connections between the drive component 3 and the power supply 5 and the control button assembly 6, and it passes through the control lever 4; the control button assembly 6 interacts with the control module via signals, outputting control commands to the control module, which in turn outputs electrical control signals to the drive component 3 based on these control commands.

[0034] It is known that drive component 3 is the core unit for realizing electronically controlled drive. As... Figure 6 As shown, the drive unit 3 mainly consists of a motor 31, a hydraulic pump 32, a hydraulic cylinder 33, and a solenoid valve (not shown in the figure). The motor 31 serves as the active power source, and its output torque directly drives the hydraulic pump 32. After the hydraulic pump 32 starts, it pressurizes the hydraulic oil and delivers it to the hydraulic cylinder 33. The hydraulic cylinder 33 converts hydraulic energy into mechanical energy, providing a continuous and stable driving force for the lifting boom 2, enabling precise lifting and lowering. The control module handles signal interaction and control command conversion. One end is connected to the control button assembly 6, and the other end is electrically connected to the motor 31. During operation, the control button assembly 6 outputs operation commands to the control module. The control module receives these commands, converts them into electrical control signals, and transmits them to the motor 31. The motor 31 drives the hydraulic pump 32 to perform outward pushing work; when the solenoid valve opens, the return oil enables the hydraulic pump 32 to retract, thus facilitating precise control of the lifting rhythm and lifting height of the lifting boom 2.

[0035] To adapt to different work scenarios, the control module has both wired and wireless control modes, which can be flexibly switched according to the actual working conditions, greatly improving operational flexibility. Specifically: Control-by-wire mode: In control-by-wire mode, the joystick 4 integrates multiple control buttons 6 (including power button, Up lift button and Down lower button). By pressing the corresponding control button 6, the operator can directly transmit control-by-wire signals to the control module. After the signal is quickly converted by the control module, the working state of the motor 31 is adjusted in real time to ensure fast response and control accuracy when operating at close range. It is especially suitable for scenarios that require fine adjustment of lifting height, such as automobile repair and equipment assembly.

[0036] Wireless Mode: In wireless mode, the control module has a built-in wireless signal receiving unit. This unit can accurately receive external wireless control signals and instantly convert them into execution commands for motor 31. Furthermore, the wireless signal receiving unit is compatible with multiple signal transmission protocols such as Bluetooth, Wi-Fi, and radio frequency, and can adapt to control signals emitted by mobile terminals (such as smartphones and tablets) or dedicated remote controls. This meets the needs of scenarios such as long-distance operation, complex working conditions (such as inconvenient close-range standing in confined spaces), or multi-device collaborative operation, comprehensively covering diverse control requirements in different working environments.

[0037] Specifically, when the wireless control signal is emitted by the mobile terminal, a dedicated control APP can be installed on the mobile terminal. The control APP not only has basic wireless control functions (such as starting / stopping lifting and adjusting lifting speed), but also displays key operating information of the equipment in real time, such as the working pressure of hydraulic cylinder 33, the real-time lifting height of boom 2, and the remaining power of power supply 5. Operators can intuitively grasp the operating status of the equipment through the APP, which facilitates timely adjustment of operating parameters. This not only improves the safety and convenience of operation, but also effectively avoids the risk of operational misjudgment due to the lack of transparency of equipment operating information, further ensuring operational safety.

[0038] Considering equipment reliability and operational safety under extreme conditions, the drive unit 3 is also equipped with an emergency return valve (not shown in the figure). The emergency return valve is connected in series in the hydraulic circuit between the hydraulic cylinder 33 and the hydraulic pump 32, serving as a backup safety guarantee in case of hydraulic system failure. When the wired control signal fails and the wireless control mode is unavailable (such as due to electrical control module failure or wiring harness breakage), the operator can manually rotate the emergency return valve to the emergency descent position, releasing pressure through the hydraulic circuit to allow the lifting boom 2 to slowly descend, preventing the heavy load from remaining stationary for an extended period due to electrical control system failure, thereby reducing the safety risks under heavy loads.

[0039] like Figures 2-5 As shown, the control stick 4 mainly consists of a saddle 41, a torsion spring 42, a hinge pin 43, an aviation plug 44, a stick body 45, a locking sleeve 46, a handle 47, and a limit pin 48. The saddle 41 is hinged to the frame 1 via two hinge pins 43 symmetrically arranged on both sides of the frame 1, providing a mounting base for the adjustment of the control stick 4. The torsion spring 42 is fitted onto the hinge pins 43, with one end inserted and fixed to the frame 1, and the other end contacting the saddle 41. This ensures that the saddle 41 is always subjected to a restoring torque, tending to maintain its initial posture when no external force is applied, thus ensuring the structural stability of the control stick 4 in the non-operational state.

[0040] like Figure 7 As shown, the saddle 41 has a insertion protrusion 411 on its top, on which a mounting cavity 4111 for inserting the rod 45 and a limiting notch 4112 communicating with the mounting cavity 4111 are also formed. The aviation plug 44 is pre-installed and fixed in the mounting cavity 4111, and it is composed of a conductive assembly 441 and a housing 442. Figure 8 , Figure 12As shown, the housing 442 has an anti-deflection protrusion 4421 formed on it. Correspondingly, the lower end of the rod 45 has an anti-deflection notch 452 that matches the anti-deflection protrusion 4421. After the rod 45 is inserted into the mounting cavity 4111 and in place, the aviation plug 44 is nested inside the rod 45. Through the precise cooperation between the anti-deflection protrusion 4421 and the anti-deflection notch 452, the circumferential rotational freedom of the rod 45 can be effectively restricted, preventing the rod 45 from deflecting during operation and ensuring that the force exerted by the operator when pushing the control lever 4 can be accurately transmitted to the frame 1. The limiting pin 48 is built into the limiting notch 4112. Its installation method is to penetrate the housing 442 of the rod 45 and the aviation plug 44 in sequence, and to be fixedly connected to the aviation plug 44 through an interference fit.

[0041] like Figure 7 , Figures 9-11 As shown, the locking sleeve 46 has a necked-holding section 461, and its inner wall is machined with an internal thread 462. Correspondingly, the outer wall of the insert protrusion 411 is machined with an external thread 4113. The two are connected detachably by the threaded pair, realizing the stable assembly of the locking sleeve 46 and the saddle 41. Figure 8 As shown, an annular groove 451 is formed on the rod body 45 for fitting and fixing the limiting ring 49, and the limiting ring 49 and the rod body 45 are interference fit to ensure that there is no relative displacement after fixing.

[0042] The necked-holding section 461 is axially penetrated by the rod body 45, with its inner wall having a clearance fit with the outer wall of the rod body 45, reserving space for fine-tuning of the axial direction of the rod body 45. The outer diameter of the limiting ring 49 is larger than the inner diameter of the necked-holding section 461, forming a radial blocking structure. When the operator rotates the locking sleeve 46 to move it downwards along the threaded joint until the necked-holding section 461 abuts against the limiting ring 49, the radial blocking of the limiting ring 49 and the axial limiting of the necked-holding section 461 work together to restrict the axial displacement freedom of the rod body 45, achieving a secure lock on the axial position of the rod body 45. Furthermore, the handle 47 is fixed to the top of the rod body 45, and its surface has anti-slip textures, providing a comfortable force application point for the operator, facilitating the pushing or rotating of the control lever 4, further optimizing the operating experience.

[0043] In practical applications, the communication component 441 serves as the communication link between the drive component 3 and the wiring harness, acting as a "bridge" in both the power transmission path and the signal transmission path. After the power supply 5 is assembled relative to the handle 47, the terminals of the power button, the Up button, and the Down button are integrated with one end of the wiring harness inside the control lever 4 (ensuring a secure connection and stable conductivity through welding, terminal crimping, or other methods). Subsequently, the wiring harness extends orderly along the dedicated wiring channel pre-set inside the control lever 4, eventually reaching the bottom of the saddle 41 and achieving a precise and secure connection with the communication component 441. The other end of the aviation plug 44 is adapted to another set of wiring harnesses leading to the motor 31, thus establishing a complete power and signal path.

[0044] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A horizontal hydraulic jack, comprising a frame, a lifting arm, a drive unit, and a control lever; the lifting arm and the drive unit are both mounted on the frame, and the lifting arm performs a lifting action under the driving force from the drive unit; the control lever is movably connected to the frame to adjust the overall position of the frame, characterized in that: It also includes a wiring harness, power supply, control button assembly, and control module that are compatible with the drive component and / or the joystick; the drive component includes a motor, a pump station, and a solenoid valve; the motor drives the pump station to perform outward pushing work, and when the solenoid valve is open, it achieves retraction work of the pump station through oil return; the power supply and the control button assembly are both integrated on the joystick; the wiring harness is used to realize the electrical connection between the drive component and the power supply and the control button assembly, and it passes through the joystick; the control button assembly outputs control commands to the control module through signal interaction with the control module, and the control module outputs electrical control signals to the drive component based on the control commands, so that the drive component can perform outward pushing work or retraction work.

2. The horizontal hydraulic jack according to claim 1, characterized in that, The pump station includes a hydraulic pump and a hydraulic cylinder; the motor is connected to the hydraulic pump to drive its operation; the control module outputs electrical control signals to the motor based on control commands to control the motor to start and stop; the hydraulic pump pressurizes the hydraulic oil and delivers it to the hydraulic cylinder, and the extension and retraction of the hydraulic cylinder provides driving force to the boom to achieve its lifting and lowering action.

3. The horizontal hydraulic jack according to claim 2, characterized in that, The control module has both thread control mode and wireless control mode. In thread control mode, the operator triggers the control button component, and the generated thread control signal is transmitted to the control module via the wiring harness to regulate the motor. In wireless control mode, the control module receives the wireless control signal and regulates the motor.

4. The horizontal hydraulic jack according to claim 3, characterized in that, The control module includes a wireless signal receiving unit; the wireless control signal is emitted by a mobile terminal or a dedicated remote control and received by the wireless signal receiving unit.

5. The horizontal hydraulic jack according to claim 4, characterized in that, The wireless signal receiving unit supports Bluetooth, Wi-Fi, or radio frequency signal transmission.

6. The horizontal hydraulic jack according to claim 3, characterized in that, When the wireless control signal is sent by the mobile terminal, the mobile terminal is equipped with a control APP; the control APP displays the working pressure of the hydraulic cylinder, the lifting height of the lifting arm, and the power supply information in real time.

7. The horizontal hydraulic jack according to claim 3, characterized in that, The drive component also includes an emergency return valve; the emergency return valve is connected in series in the hydraulic circuit between the hydraulic cylinder and the hydraulic pump; when the thread control signal fails and the wireless control mode is unavailable, the emergency return valve is rotated to the emergency descent position, and the hydraulic circuit is depressurized to allow the boom to slowly descend.

8. The horizontal hydraulic jack according to any one of claims 1-7, characterized in that, The control stick includes a saddle, a torsion spring, a hinge shaft, a rod body, a locking sleeve, a handle, a limit pin, and an aviation connector. The saddle is hinged to the frame via the hinge shaft. The torsion spring is fitted onto the hinge shaft, with its two ends abutting / connecting to the saddle and the frame, respectively. The saddle is subjected to a restoring torque and tends to maintain its initial posture. The saddle has an insertion protrusion. The insertion protrusion has a mounting cavity for inserting the rod body and a limiting notch communicating with the mounting cavity. The aviation connector is fixedly installed inside the saddle, and its outer side wall is formed with an anti-deflection protrusion. The lower end of the rod body has a connection with the anti-deflection protrusion. The device features a matching anti-deflection notch; the limiting pin has the limiting notch built into it, passes through the rod body and the aviation plug in sequence, and is fixed to the aviation plug by an interference fit; the locking sleeve has a necked-back section; the rod body has a limiting structure adapted to the necked-back section; the necked-back section is axially penetrated by the rod body, and the locking sleeve is connected to the insertion protrusion by a threaded pair, thereby limiting the axial displacement of the rod body by means of the necked-back section and the limiting structure; and when the locking sleeve is tightened to contact the limiting structure, the axial position of the rod body is locked; the handle is fixed to the top of the rod body.

9. The horizontal hydraulic jack according to claim 8, characterized in that, The aviation plug is composed of a conductive component and a housing; the conductive component is used to realize signal communication and / or current transmission between the drive component and the wiring harness; the anti-deflection protrusion is formed on the housing.

10. The horizontal hydraulic jack according to claim 8, characterized in that, The inner wall of the locking sleeve necking section is clearance-fitted with the outer wall of the rod body; the limiting structure is a limiting ring; the limiting ring is fitted and fixed to the rod body; the outer diameter of the limiting ring is larger than the inner diameter of the necking section to form a radial block; when the necking section abuts against the limiting ring, the axial displacement freedom of the rod body is restricted by the blocking of the limiting ring and the limiting of the necking section.

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