A jack with exchangeable piston rod friction head

Abstract

The present application relates to the technical field of hoisting equipment, in particular to a jack with replaceable piston rod friction head, comprising a plug-in rod, a friction head, an expansion module and a magnet; the plug-in rod is movably inserted into the top port of the piston rod of the jack body, the lower end surface of the upper shaft section of the plug-in rod is in abutment with the upper end surface of the piston rod; the friction head is arranged at the top end of the plug-in rod; the expansion module is arranged in the interior of the piston rod and connected with the plug-in rod, and is used for expanding and positioning the plug-in rod; the magnet is arranged in the inner cavity of the piston rod, and is used for magnetically attracting the plug-in rod. The device sets the expansion module and the magnet in the interior of the piston rod, after the user inserts the plug-in rod with the friction head into the piston rod, the plug-in rod is automatically pulled downward to extrude and expand the expansion module by the magnetic attraction force generated by the magnet, so that the expansion and positioning of the plug-in rod are realized, which not only ensures the structural stability of the device, but also effectively improves the problem of structural jam caused by environmental erosion or external physical impact.

Description

Technical Field

[0001] This invention relates to the field of lifting equipment technology, and in particular to a jack with an interchangeable piston rod friction head. Background Technology

[0002] A jack is a common type of lifting equipment, widely used in vehicle repair, industrial lifting, and other fields.

[0003] In the prior art, to facilitate the replacement of the friction head, fasteners are often used to fix the friction head to the piston rod of the jack body. For example, Chinese invention patent CN203640747U discloses a hydraulic support, a lifting jack body and its piston rod; wherein the piston rod of the lifting jack body includes: a piston rod body and a friction part; the friction part is disposed at the end of the piston rod body, and the friction part is detachably connected to the piston rod body by a U-shaped clip to facilitate the replacement of the friction part.

[0004] However, in practical applications, due to the complex working conditions of the main body of the jack, the U-shaped clamp is easily corroded by the environment and rusts, or it undergoes plastic yielding deformation due to external impact, which in turn causes structural jamming and makes it difficult to disassemble the friction part. Summary of the Invention

[0005] To address the technical problems existing in the prior art, embodiments of the present invention provide a jack with an interchangeable piston rod friction head, comprising: The insert rod is movably inserted into the top port of the piston rod of the jack body, and the lower end face of the upper shaft section of the insert rod abuts against the upper end face of the piston rod. The friction head is located at the top of the insertion rod; The tensioning module is located inside the piston rod and is connected to the insertion rod. It is used to tension and position the insertion rod. A magnet is disposed in the inner cavity of the piston rod, and the magnet is located between the insertion rod and the first piston member of the piston rod, and is used to magnetically attract the insertion rod.

[0006] Furthermore, the tensioning module includes: A fixed protrusion is fixedly installed on the inner wall of the piston rod. The fixed protrusion is an annular part, and the lower shaft section of the insertion rod is movably inserted into the inner cavity of the fixed protrusion. Several tensioning components are set on the fixed protrusion, and the several tensioning components are connected to the insertion rod to tighten and position the insertion rod; The movable part is located in the inner cavity of the piston rod. The movable part is connected to several tensioning components. The top of the movable part abuts against the lower end face of the intermediate shaft section of the insert rod. Several elastic elements are fixedly mounted on the fixed protrusion, and these elastic elements are connected to the movable element to provide elastic support for the movable element.

[0007] Furthermore, the tensioning component includes: The receiving cavity is formed inside the fixed protrusion, and the receiving cavity is exposed on the upper end face of the fixed protrusion and the inner cavity sidewall surface of the fixed protrusion. The first tensioning block is movably disposed in the accommodating cavity. The first tensioning block is slidably connected to the inner wall of the accommodating cavity along the axial direction of the piston rod. The top end of the first tensioning block is fixedly connected to the movable part. The second tightening block is movably disposed in the accommodating cavity. The second tightening block is located between the first tightening block and the insert rod. The second tightening block is slidably connected to the inner wall of the accommodating cavity along the radial direction of the piston rod. The contact surface between the second tightening block and the first tightening block is an inclined surface. The thickness of the top end of the second tightening block is less than the thickness of the bottom end of the second tightening block, which is used to radially compress and position the insert rod.

[0008] Furthermore, the tensioning assembly also includes: a socket, which is opened on the lower end face of the fixed protrusion and communicates with the receiving cavity. The bottom end of the first tensioning block is movably inserted into the socket. When several tensioning assemblies tension and position the insertion rod, the bottom end of the first tensioning block protrudes from the lower end face of the fixed protrusion.

[0009] Furthermore, the device also includes an assembly module, which is mounted on the insert rod and connected to the friction head, for assembling the ball joint of the friction head onto the top of the insert rod.

[0010] Furthermore, the assembly module includes: The assembly cavity is located inside the insert rod. The upper end surface of the insert rod is spherical, and the bottom surface of the friction head is in contact with the upper end surface of the insert rod. An assembly hole is formed on the upper end face of the insertion rod, and the assembly hole communicates with the assembly cavity; The sphere is movably positioned within the assembly cavity; A ball joint assembly is located in the assembly cavity. The ball joint assembly is connected to the friction head and is used to assemble the friction head ball joint onto the top of the insert rod. The braking assembly, located inside the piston rod, is used to compress and brake the ball.

[0011] Furthermore, the ball joint assembly includes: The ball cup component is movably installed in the assembly cavity. The ball cup component is located between the sphere and the assembly hole. The upper surface of the ball cup component is spherical and fits against the inner wall surface of the assembly cavity. The inner cavity shape of the ball cup component matches the sphere. The insert is fixedly installed at the bottom of the friction head, and the insert is movably inserted into the assembly hole; The plug-in column is fixedly installed on the ball cup part, and the plug-in column is movably plugged into the plug tube.

[0012] Furthermore, the braking assembly includes: A magnetic metal component is fixedly mounted on the inner wall of the piston rod, and the magnetic metal component is located between the first piston component and the magnet; The first piston is movably inserted into the bottom port of the piston rod, and the radial cross-sectional shape of the top end of the first piston matches the radial cross-sectional shape of the inner cavity of the piston rod. The second piston is movably disposed in the inner cavity of the piston rod. The second piston is located between the expansion module and the magnetic metal part, and the circumferential sidewall of the second piston is in contact with the circumferential inner wall of the piston rod. The magnet is fixedly installed at the bottom of the second piston component, and the magnet is located between the second piston component and the magnetic metal component; The connecting hole is located on the bottom wall of the inner cavity of the assembly cavity, and the connecting hole is exposed on the bottom end face of the insertion rod. The brake component is movably disposed in the assembly cavity. The brake component is located between the ball and the connecting hole. The inner cavity shape of the brake component matches the contour shape of the ball and is used to compress and brake the ball. The connecting rod is fixedly installed at the bottom of the brake component. When the brake component applies pressure to the ball, the bottom end of the connecting rod passes through the connecting hole and abuts against the top of the second piston component.

[0013] Furthermore, the first piston component includes: The assembly shaft is movably inserted into the bottom port of the piston rod, and the assembly shaft is arranged along the axial direction of the piston rod; The lower piston block is fixedly sleeved on the bottom end of the assembly shaft. The outer ring surface of the lower piston block is in contact with the circumferential side wall of the inner cavity of the assembly cylinder of the jack body. The lower piston block is located between the piston rod and the bottom port of the assembly cylinder. The upper piston block is movably sleeved on the assembly shaft. The inner ring surface of the upper piston block is in contact with the circumferential side wall of the assembly shaft, and the outer ring surface of the upper piston block is in contact with the circumferential side wall of the inner cavity of the piston rod. Several limiting protrusions are fixedly installed in the bottom port of the piston rod, and the limiting protrusions are all located between the upper piston block and the lower piston block.

[0014] Furthermore, this device also includes: The control valve is fixedly installed on the outer shell of the jack body. One end of the control valve is connected to the upper part of the inner cavity of the assembly cylinder of the jack body, and the other end of the control valve is connected to the cavity between the assembly cylinder and the outer shell. A sealing element is fixedly sleeved on the bottom end of the piston rod. The outer ring surface of the sealing element is in contact with the circumferential inner wall surface of the piston rod assembly cylinder. The sealing element is located between the first piston and the top port of the assembly cylinder and is used to seal the gap between the piston rod and the assembly cylinder.

[0015] A jack with an adjustable piston rod friction head according to an embodiment of the present invention has the following beneficial effects: 1. This device sets the expansion module and magnet inside the piston rod. After the user inserts the rod with the friction head into the piston rod, the magnetic attraction generated by the magnet automatically pulls the rod downward to squeeze the expansion module, thereby achieving expansion and positioning of the rod. This not only ensures the structural stability of the device, but also effectively improves the problem of structural jamming caused by environmental erosion or external physical impact, solving the defects existing in the prior art.

[0016] 2. This device constructs a sealed air cavity by movably arranging a first piston and a second piston within the piston rod. On one hand, utilizing the compressibility of air, the increased air pressure within the air cavity activates the braking component after the friction head comes into contact with a heavy object, thereby moderately increasing the deflection resistance of the friction head. This flexible braking design not only improves the structural stability of the device but also prevents the friction head from being rigidly locked, allowing it to adaptively deflect according to the tilting posture of the heavy object during lifting, thus enhancing the device's resistance to eccentric loads. On the other hand, this air cavity also serves as an energy storage function. When the friction head needs to be replaced, the piston rod can be hydraulically locked by closing the control valve, restricting its upward extension. At this time, the continuously input hydraulic thrust is converted into compressive potential energy within the air cavity. When the air pressure accumulated in the air cavity exceeds the magnetic attraction threshold of the magnet, the second piston disengages from the magnetic attraction and impacts the connecting rod and the first tensioning block upward, thereby releasing the locking state of the insertion rod by the tensioning module, facilitating the user's disassembly of the insertion rod equipped with the friction head.

[0017] It should be understood that both the foregoing general description and the following detailed description are exemplary and intended to provide further illustration of the claimed technology. Attached Figure Description

[0018] Figure 1 This is a perspective view of an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of an embodiment of the present invention; Figure 3 This is a part drawing of the insertion rod according to an embodiment of the present invention; Figure 4 This is an assembly diagram of the expansion module according to an embodiment of the present invention; Figure 5 This is an exploded view of the structure of the expansion module according to an embodiment of the present invention; Figure 6 This is an assembly diagram of the assembly module according to an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1-Piston rod, 11-Limiting protrusion, 12-First piston component, 121-Assembly shaft, 122-Lower piston block, 123-Upper piston block, 2-Outer casing, 21-Hydraulic control system, 22-Return valve, 3-Assembly cylinder, 4-Insertion rod, 41-Upper shaft section, 42-Intermediate shaft section, 43-Lower shaft section, 5-Friction head, 6-Tightening module, 61-Fixing protrusion, 62-Tightening assembly, 621-Accommodating cavity, 62 2-First tightening block, 623-Second tightening block, 624-Insertion hole, 63-Moving part, 64-Elastic part, 7-Magnet, 8-Assembly module, 81-Assembly cavity, 82-Assembly hole, 83-Sphere, 841-Spherical cup part, 842-Insertion cylinder, 843-Insertion column, 851-Magnetic metal part, 852-Second piston part, 853-Brake part, 854-Connecting rod, 9-Control valve, 10-Sealing part. Detailed Implementation

[0020] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, further illustrating the present invention.

[0021] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of the embodiments with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are only for reference to the directions in the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the present invention. Furthermore, in all embodiments, the same reference numerals denote the same elements.

[0022] Specifically, such as Figures 1-3As shown in the embodiment of the present invention, a jack with an interchangeable piston rod 1 and friction head 5 includes: a jack body, an insert rod 4, a friction head 5, a tightening module 6, and a magnet 7; wherein the jack body is composed of a housing 2, an assembly cylinder 3, a piston rod 1, a hydraulic control system 21, and a return valve 22; the housing 2 stores hydraulic oil; the assembly cylinder 3 is fixedly disposed in the inner cavity of the housing 2 along the axial direction of the housing 2, and the top port of the assembly cylinder 3 is exposed on the top surface of the housing 2; the piston rod 1 is movably inserted into the inner cavity of the assembly cylinder 3 through the top port of the assembly cylinder 3, and the bottom end of the piston rod 1 is provided with The assembly includes a first piston 12, with a hollow piston rod 1. An oil inlet (not shown in the figure) is provided on the assembly cylinder 3. One end of the oil inlet connects to the top of the inner cavity of the assembly cylinder 3, and the other end connects to the cavity between the outer shell 2 and the assembly cylinder 3. The oil inlet is located above the first piston 12. A hydraulic control system 21 is mounted on the outer shell 2. The input end of the hydraulic control system 21 connects to the cavity between the assembly cylinder 3 and the outer shell 2, and the output end of the hydraulic control system 21 connects to the bottom of the inner cavity of the assembly cylinder 3. The output end of the hydraulic control system 21 is located between the first piston 12 and the outer shell 2. Between the bottom walls of the cavity, hydraulic oil stored in the cavity between the assembly cylinder 3 and the outer shell 2 is transferred to the bottom of the inner cavity of the assembly cylinder 3, thereby driving the piston rod 1 to rise; the return valve 22 is installed on the outer shell 2, the input end of the return valve 22 is connected to the bottom of the inner cavity of the assembly outer shell 2, and the output end of the return valve 22 is connected to the cavity between the assembly cylinder 3 and the outer shell 2. When the return valve 22 is open, the hydraulic oil located between the first piston 12 and the bottom wall of the inner cavity of the outer shell 2 in the assembly cylinder 3 can flow back to the cavity between the assembly cylinder 3 and the outer shell 2 through the return valve 22; the insertion rod 4 is movably inserted into the jack. In the top port of the piston rod 1 of the main body, the insertion rod 4 is composed of an upper shaft section 41, an intermediate shaft section 42 and a lower shaft section 43. The intermediate shaft end is located between the upper shaft section 41 and the lower shaft section 43. The lower end face of the upper shaft section 41 of the insertion rod 4 abuts against the upper end face of the piston rod 1. A friction head 5 is set at the top of the insertion rod 4. A tensioning module 6 is set inside the piston rod 1. The tensioning module 6 is connected to the insertion rod 4 and is used to tension and position the insertion rod 4. A magnet 7 is set in the inner cavity of the piston rod 1. The magnet 7 is located between the insertion rod 4 and the first piston member 12 of the piston rod 1 and is used to magnetically attract the insertion rod 4.

[0023] In this embodiment, the user inserts the rod 4, which is equipped with a friction head 5 at the top, into the inner cavity of the piston rod 1 through the top port. Under the magnetic drive of the magnet 7, the piston rod 1 presses down on the expansion module 6 until the lower end face of the upper shaft section 41 of the rod 4 abuts against the top face of the piston rod 1. At this time, the rod 4 is installed in place, and the expansion module 6 simultaneously performs radial compression on the lower shaft section 43 of the rod 4, thereby eliminating the assembly gap of the rod 4 and realizing the expansion and positioning of the rod 4.

[0024] During the lifting process of the jack, the return valve 22 is in the closed state. The hydraulic control system 21 transmits the hydraulic oil in the cavity between the assembly cylinder 3 and the outer shell 2 to the bottom of the inner cavity of the assembly cylinder 3, driving the first piston 12 and piston rod 1 to move upward. At the same time, the hydraulic oil in the cavity above the first piston 12 in the assembly cylinder 3 flows back to the cavity between the assembly cylinder 3 and the outer shell 2 through the oil supply hole, thereby driving the piston rod 1 to drive the insert rod 4 and friction head 5 mounted thereon to lift the heavy object.

[0025] When the user controls the piston rod 1 to fall back, the user opens the return valve, connecting the bottom of the inner wall of the assembly cylinder 3 with the bottom of the inner cavity of the outer shell 2. This allows the hydraulic oil in the lower cavity of the first piston member 12 in the assembly cylinder 3 to flow into the cavity between the assembly cylinder 3 and the outer shell 2 through the return valve 22. At the same time, the hydraulic oil in the cavity between the assembly cylinder 3 and the outer shell 2 flows into the cavity above the first piston member 12 in the assembly cylinder 3 through the oil supply hole, causing the piston rod 1 to fall back under the action of gravity.

[0026] Furthermore, such as Figures 1-5 As shown, the tensioning module 6 includes: a fixed protrusion 61, several tensioning components 62, a movable member 63, and several elastic members 64; the fixed protrusion 61 is fixedly disposed on the inner wall of the piston rod 1, and the fixed protrusion 61 is an annular member, with the lower shaft section 43 of the insertion rod 4 movably inserted into the inner cavity of the fixed protrusion 61; several tensioning components 62 are disposed on the fixed protrusion 61, and the several tensioning components 62 are connected to the insertion rod 4 for tensioning and positioning the insertion rod 4; the movable member 63 is disposed in the inner cavity of the piston rod 1, and the movable member 63 is connected to the several tensioning components 62, with the top of the movable member 63 abutting against the lower end face of the middle shaft section 42 of the insertion rod 4; several elastic members 64 are fixedly disposed on the fixed protrusion 61, and the several elastic members 64 are connected to the movable member 63 for elastically supporting the movable member 63.

[0027] Furthermore, such as Figures 1-5As shown, the tensioning assembly 62 includes: a receiving cavity 621, a first tensioning block 622, and a second tensioning block 623; the receiving cavity 621 is formed inside the fixing protrusion 61, and the receiving cavity 621 is exposed to the upper end face of the fixing protrusion 61 and the inner cavity sidewall surface of the fixing protrusion 61; the first tensioning block 622 is movably disposed in the receiving cavity 621, and the first tensioning block 622 is slidably connected to the inner wall of the receiving cavity 621 along the axial direction of the piston rod 1, and the top end of the first tensioning block 622 is connected to the piston rod 1. The moving part 63 is fixedly connected; the second expansion block 623 is movably disposed in the accommodating cavity 621. The second expansion block 623 is located between the first expansion block 622 and the insertion rod 4. The second expansion block 623 is slidably connected to the inner wall of the accommodating cavity 621 along the radial direction of the piston rod 1. The contact surface between the second expansion block 623 and the first expansion block 622 is an inclined surface. The thickness of the top end of the second expansion block 623 is less than the thickness of the bottom end of the second expansion block 623, which is used to radially compress and position the insertion rod 4.

[0028] Furthermore, such as Figure 2 , 4 As shown in ~6, the tensioning assembly 62 further includes: a socket 624, which is opened on the lower end face of the fixing protrusion 61 and communicates with the receiving cavity 621. The bottom end of the first tensioning block 622 is movably inserted into the socket 624. When several tensioning assemblies 62 tension and position the insertion rod 4, the bottom end of the first tensioning block 622 protrudes from the lower end face of the fixing protrusion 61.

[0029] In this embodiment, the insertion rod 4 is driven by both magnetic force and gravity, and the movable part 63 presses down on the first tensioning block 622 of the multiple tensioning components 62; during the downward movement of the first tensioning block 622, the second tensioning block 623 is simultaneously driven to move radially inward to press the insertion rod 4, thereby realizing the radial locking and positioning of the insertion rod 4, eliminating its assembly gap, and realizing the tensioning and positioning of the insertion rod 4; at the same time, the bottom end of the first tensioning block 622 protrudes downward from the lower end face of the fixed protrusion 61.

[0030] Furthermore, such as Figure 4 , 5 As shown, the device also includes: an assembly module 8, which is disposed on the insertion rod 4 and connected to the friction head 5, for ball joint assembly of the friction head 5 to the top of the insertion rod 4.

[0031] Furthermore, such as Figure 2 , 3As shown in Figure 6, the assembly module 8 includes: an assembly cavity 81, an assembly hole 82, a ball 83, a ball joint assembly, and a braking assembly; the assembly cavity 81 is located inside the insert rod 4, the upper end surface of the insert rod 4 is spherical, and the bottom surface of the friction head 5 is in contact with the upper end surface of the insert rod 4; the assembly hole 82 is located on the upper end surface of the insert rod 4 and communicates with the assembly cavity 81; the ball 83 is movably disposed in the assembly cavity 81; the ball joint assembly is disposed in the assembly cavity 81 and is connected to the friction head 5, used to assemble the friction head 5 onto the top of the insert rod 4; the braking assembly is disposed in the inner cavity of the piston rod 1 and is used to compress and brake the ball 83.

[0032] Furthermore, such as Figure 2 , 3 As shown in Figure 6, the ball joint assembly includes: a ball cup 841, a sleeve 842, and a connecting post 843; the ball cup 841 is movably disposed in the assembly cavity 81, and the ball cup 841 is located between the ball 83 and the assembly hole 82. The upper surface of the ball cup 841 is spherical, and the upper surface of the ball cup 841 is in contact with the inner cavity top wall surface of the assembly cavity 81. The inner cavity shape of the ball cup 841 matches the ball 83; the sleeve 842 is fixedly disposed at the bottom of the friction head 5, and the sleeve 842 is movably inserted into the assembly hole 82; the connecting post 843 is fixedly disposed on the ball cup 841, and the connecting post 843 is movably inserted into the sleeve 842.

[0033] In this embodiment, when using this device for lifting operations, before the friction head 5 contacts the load, the user can adjust the deflection angle of the friction head 5 according to the tilt angle of the load-bearing surface, so that the friction head 5 can better fit the load-bearing surface of the load.

[0034] Furthermore, such as Figure 2 , 3As shown in Figure 6, the braking assembly includes: a magnetic metal part 851, a second piston part 852, a connecting hole, a braking part 853, and a connecting rod 854; the magnetic metal part 851 is fixedly disposed on the inner wall of the piston rod 1, and is located between the first piston part 12 and the magnet 7; the first piston part 12 is movably inserted into the bottom port of the piston rod 1, the radial cross-sectional shape of the top end of the first piston part 12 matches the radial cross-sectional shape of the inner cavity of the piston rod 1, and the radial cross-sectional shape of the bottom end of the first piston part 12 matches the radial cross-sectional shape of the inner cavity of the mounting cylinder 3 of the jack body; the second piston part 852 is movably disposed in the inner cavity of the piston rod 1, and is located between the expansion module 6 and the magnetic metal part 851, the circumferential sidewall of the second piston part 852 is in contact with the circumferential inner wall of the piston rod 1; the magnet 7 is fixedly disposed on the first piston part 853 and the connecting rod 854. At the bottom of the second piston component 852, the magnet 7 is located between the second piston component 852 and the magnetic metal component 851; the connecting hole is opened on the bottom wall of the inner cavity of the assembly cavity 81, and the connecting hole is exposed on the bottom end face of the insert rod 4; the brake component 853 is movably disposed in the assembly cavity 81, and the brake component 853 is located between the ball 83 and the connecting hole. The inner cavity shape of the brake component 853 matches the contour shape of the ball 83, and is used to compress and brake the ball 83; the connecting rod 854 is fixedly disposed at the bottom of the brake component 853. When the brake component 853 compresses and brakes the ball 83, the bottom end of the connecting rod 854 passes through the connecting hole and abuts against the top of the second piston component 852. When the brake component 853 compresses and brakes the ball 83, the bottom end face of the connecting rod 854 is on the same plane as the bottom end face of the second tension block 623 of the plurality of tensioning components 62.

[0035] Furthermore, such as Figure 2 , 3 As shown in Figure 6, the first piston component 12 includes: an assembly shaft 121, a lower piston block 122, and an upper piston block 123; the assembly shaft 121 is movably inserted into the bottom port of the piston rod 1, and the assembly shaft 121 is arranged along the axial direction of the piston rod 1; the lower piston block 122 is fixedly sleeved on the bottom end of the assembly shaft 121, and the outer ring surface of the lower piston block 122 is in contact with the circumferential side wall of the inner cavity of the assembly cylinder 3 of the jack body, and the lower piston block 122 is located between the piston rod 1 and the bottom port of the assembly cylinder 3; the upper piston block 123... 23 is movably sleeved on the assembly shaft 121. The inner ring surface of the upper piston block 123 is in contact with the circumferential side wall of the assembly shaft 121, and the outer ring surface of the upper piston block 123 is in contact with the circumferential side wall of the inner cavity of the piston rod 1. A limiting mechanism is provided at the top of the assembly shaft 121 to prevent the upper piston block 123 from disengaging from the assembly shaft 121. Several limiting protrusions 11 are fixedly provided in the bottom port of the piston rod 1, and the several limiting protrusions 11 are all located between the upper piston block 123 and the lower piston block 122.

[0036] When using this device for lifting operations, before the friction head 5 contacts the load, the lower piston block 122 moves upward along the assembly cylinder 3 under the drive of hydraulic oil. The hydraulic oil between the lower piston block 122 and the bottom end of the piston rod 1 is also pressed into the inner cavity of the piston rod 1, driving the upper piston block 123 to move upward along the piston rod 1. This causes the air in the cavity between the upper piston block 123 and the second piston member 852 to be initially compressed. The second piston member 852 moves upward under the drive of air pressure. During this process, the second piston member 852 drives the piston rod 1 to extend upward under the magnetic force between the magnet 7 and the magnetic metal member 851.

[0037] After the friction head 5 contacts the weight, the piston rod 1 stops extending upward due to the weight's resistance. As hydraulic oil is further injected into the lower cavity of the lower piston block 122, the lower piston block 122 and the upper piston block 123 move upward synchronously. The air in the cavity between the upper piston block 123 and the second piston member 852 is further compressed. When the air pressure inside the cavity between the upper piston block 123 and the second piston member 852 reaches a certain level, the second piston member 852 overcomes the attraction between the magnet 7 and the magnetic metal part 851. The piston moves upward until the second piston 852 presses against the connecting rod 854, which in turn drives the brake 853 to press against the ball 83, increasing the rotational resistance of the ball cup 841, thereby increasing the deflection resistance of the friction head 5 and enhancing the structural stability of the device. Then, as the lower piston block 122 moves further upward, after the lower piston block 122 abuts against the bottom end of the piston rod 1, the driving force from the hydraulic oil on the lower piston block 122 directly acts on the piston rod 1, thereby driving the piston rod 1 to rise further and lift the heavy object.

[0038] Furthermore, such as Figure 2 , 6 As shown, the device also includes: a control valve 9 and a sealing element 10; the control valve 9 is fixedly installed on the outer shell 2 of the jack body, one end of the control valve 9 is connected to the upper part of the inner cavity of the assembly cylinder 3 of the jack body through an oil inlet, and the other end of the control valve 9 is connected to the cavity between the assembly cylinder 3 and the outer shell 2, for controlling the opening and closing of the oil inlet; the sealing element 10 is fixedly sleeved on the bottom end of the piston rod 1, the outer ring surface of the sealing element 10 is in contact with the circumferential inner wall surface of the assembly cylinder 3 of the piston rod 1, and the sealing element 10 is located between the first piston 12 and the top port of the assembly cylinder 3, for sealing the gap between the piston rod 1 and the assembly cylinder 3.

[0039] When the user needs to replace the friction head 5 after completing the lifting operation with this device, the user can close the control valve 9 to block the oil supply port, and then control the hydraulic control system 21 to supply hydraulic oil to the lower cavity of the lower piston block 122. The lower piston block 122 and the upper piston block 123 move upward under the drive of the hydraulic oil. At this time, since the oil supply port is blocked by the control valve 9, the hydraulic oil in the upper cavity of the seal 10 cannot flow back to the cavity between the assembly cylinder 3 and the outer shell 2, thus forming a hydraulic lock and restricting the piston rod 1 from extending upward. When the cavity pressure between the upper piston block 123 and the second piston 852 reaches the preset value, the second piston 852 overcomes the magnetic force between the magnet 7 and the magnetic metal part 851 and impacts the connecting rod 854 and the bottom end of the first tension block 622 of several tensioning components 62 upward, so as to release the tensioning module 6 from the tensioning positioning state of the insertion rod 4, allowing the user to easily remove the insertion rod 4 equipped with the friction head 5, which is convenient for the user to replace different types of friction heads 5.

[0040] Above, refer to Figures 1-6 A jack with an adjustable piston rod 1 and friction head 5 according to an embodiment of the present invention is described, which has the following beneficial effects: 1. This device sets the expansion module 6 and the magnet 7 inside the piston rod 1. After the user inserts the rod 4 with the friction head 5 into the piston rod 1, the magnetic attraction generated by the magnet 7 automatically pulls the rod 4 downward to squeeze the expansion module 6, thereby achieving expansion and positioning of the rod 4. This not only ensures the structural stability of the device, but also effectively improves the problem of structural jamming caused by environmental erosion or external physical impact, and solves the defects existing in the prior art.

[0041] 2. This device constructs a sealed air cavity between a first piston 12 and a second piston 852 that are movably arranged within the piston rod 1. Utilizing the compressibility of air, the increased air pressure within the air cavity activates the braking assembly after the friction head 5 comes into contact with the load, thus moderately increasing the deflection resistance of the friction head 5. This flexible braking design enhances the structural stability of the device while preventing the friction head 5 from being rigidly locked. This allows the friction head 5 to adaptively deflect according to the tilting posture of the load during lifting, enhancing the device's resistance to eccentric loads. On the other hand, the air cavity also serves as an energy storage function. When the friction head 5 needs to be replaced, the piston rod 1 can be hydraulically locked by closing the control valve 9 to restrict its upward extension. At this time, the continuously input hydraulic thrust is converted into compressive potential energy in the air cavity. When the air pressure accumulated in the air cavity exceeds the magnetic attraction threshold of the magnet 7, the second piston 852 disengages from the magnetic attraction and impacts the connecting rod 854 and the first tensioning block 622 upward to release the positioning lock of the tensioning module 6 on the insertion rod 4, making it convenient for the user to disassemble the insertion rod 4 equipped with the friction head 5.

[0042] It should be noted that, in this specification, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0043] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A jack with an interchangeable piston rod friction head, characterized in that, Include: The insert rod is movably inserted into the top port of the piston rod of the jack body, and the lower end face of the upper shaft section of the insert rod abuts against the upper end face of the piston rod. A friction head is disposed at the top of the insertion rod; An expansion module is disposed inside the piston rod and is connected to the insertion rod for expanding and positioning the insertion rod; A magnet is disposed in the inner cavity of the piston rod, and the magnet is located between the insertion rod and the first piston member of the piston rod, for magnetically attracting the insertion rod.

2. The jack with an adjustable piston rod friction head as described in claim 1, characterized in that, The expansion module includes: A fixed protrusion is fixedly disposed on the inner wall of the piston rod. The fixed protrusion is an annular component, and the lower shaft section of the insertion rod is movably inserted into the inner cavity of the fixed protrusion. Several tensioning components are disposed on the fixed protrusion, and the several tensioning components are connected to the insertion rod for tensioning and positioning the insertion rod; A movable component is disposed in the inner cavity of the piston rod. The movable component is connected to the plurality of tensioning assemblies. The top of the movable component abuts against the lower end face of the intermediate shaft section of the insertion rod. Several elastic elements are fixedly mounted on the fixed protrusion, and the elastic elements are connected to the movable element to elastically support the movable element.

3. The jack with an adjustable piston rod friction head as described in claim 2, characterized in that, The tensioning assembly includes: A receiving cavity is formed inside the fixing protrusion, and the receiving cavity is exposed on the upper end face of the fixing protrusion and the inner cavity sidewall surface of the fixing protrusion; The first expansion block is movably disposed in the accommodating cavity. The first expansion block is slidably connected to the inner wall of the accommodating cavity along the axial direction of the piston rod. The top end of the first expansion block is fixedly connected to the movable part. The second expansion block is movably disposed in the accommodating cavity. The second expansion block is located between the first expansion block and the insertion rod. The second expansion block is slidably connected to the inner wall of the accommodating cavity along the radial direction of the piston rod. The contact surface between the second expansion block and the first expansion block is an inclined surface. The thickness of the top end of the second expansion block is less than the thickness of the bottom end of the second expansion block, which is used to radially compress and position the insertion rod.

4. A jack with an interchangeable piston rod friction head as described in claim 3, characterized in that, The tightening assembly further includes: a insertion hole, the insertion hole being formed on the lower end face of the fixed protrusion, the insertion hole communicating with the receiving cavity, the bottom end of the first tightening block being movably inserted into the insertion hole, and when the plurality of tightening assemblies tighten and position the insertion rod, the bottom end of the first tightening block protruding from the lower end face surface of the fixed protrusion.

5. A jack with an adjustable piston rod friction head as described in claim 1, characterized in that, It also includes: an assembly module disposed on the insert rod, the assembly module being connected to the friction head, for assembling the friction head ball joint onto the top end of the insert rod.

6. A jack with an interchangeable piston rod friction head as described in claim 5, characterized in that, The assembly module includes: An assembly cavity is formed inside the insert rod, the upper end surface of the insert rod is spherical, and the bottom surface of the friction head is in contact with the upper end surface of the insert rod; An assembly hole is formed on the upper end face of the insertion rod, and the assembly hole communicates with the assembly cavity; The sphere is movably disposed within the assembly cavity; A ball joint assembly is disposed in the assembly cavity, and the ball joint assembly is connected to the friction head for ball joint assembly of the friction head onto the top end of the insert rod. A braking assembly, disposed within the inner cavity of the piston rod, is used to compress and brake the ball.

7. A jack with an interchangeable piston rod friction head as described in claim 6, characterized in that, The ball joint assembly includes: A ball-shaped cup component is movably disposed in the assembly cavity. The ball-shaped cup component is located between the sphere and the assembly hole. The upper surface of the ball-shaped cup component is spherical. The upper surface of the ball-shaped cup component is in contact with the inner cavity top wall surface of the assembly cavity. The inner cavity shape of the ball-shaped cup component matches the sphere. A plug is fixedly disposed at the bottom of the friction head, and the plug is movably inserted into the assembly hole; A plug-in column is fixedly installed on the ball cup component, and the plug-in column is movably plugged into the plug cylinder.

8. A jack with an interchangeable piston rod friction head as described in claim 6, characterized in that, The braking assembly includes: A magnetic metal component is fixedly disposed on the inner wall of the piston rod, and the magnetic metal component is located between the first piston component and the magnet; The first piston is movably inserted into the bottom port of the piston rod, and the radial cross-sectional shape of the top end of the first piston matches the radial cross-sectional shape of the inner cavity of the piston rod. The second piston is movably disposed in the inner cavity of the piston rod. The second piston is located between the expansion module and the magnetic metal part, and the circumferential sidewall of the second piston is in contact with the circumferential inner wall of the piston rod. The magnet is fixedly disposed at the bottom of the second piston component, and the magnet is located between the second piston component and the magnetic metal component; A connecting hole is formed on the bottom wall of the inner cavity of the assembly cavity, and the connecting hole is exposed on the bottom end face of the insertion rod; A braking component is movably disposed in the assembly cavity. The braking component is located between the ball and the connecting hole. The inner cavity shape of the braking component matches the contour shape of the ball and is used to compress and brake the ball. A connecting rod is fixedly installed at the bottom of the brake component. When the brake component applies pressure to the ball, the bottom end of the connecting rod passes through the connecting hole and abuts against the top of the second piston component.

9. A jack with an interchangeable piston rod friction head as described in claim 8, characterized in that, The first piston component includes: An assembly shaft is movably inserted into the bottom port of the piston rod, and the assembly shaft is arranged along the axial direction of the piston rod; The lower piston block is fixedly sleeved on the bottom end of the assembly shaft. The outer ring surface of the lower piston block is in contact with the circumferential side wall of the inner cavity of the assembly cylinder of the jack body. The lower piston block is located between the piston rod and the bottom port of the assembly cylinder. The upper piston block is movably sleeved on the assembly shaft. The inner ring surface of the upper piston block is in contact with the circumferential sidewall of the assembly shaft, and the outer ring surface of the upper piston block is in contact with the circumferential sidewall of the inner cavity of the piston rod. A plurality of limiting protrusions are fixedly provided in the bottom port of the piston rod, and the plurality of limiting protrusions are all located between the upper piston block and the lower piston block.

10. A jack with an interchangeable piston rod friction head as described in claim 1, characterized in that, Also includes: A control valve is fixedly installed on the outer shell of the jack body. One end of the control valve is connected to the upper part of the inner cavity of the assembly cylinder of the jack body, and the other end of the control valve is connected to the cavity between the assembly cylinder and the outer shell. A sealing element is fixedly sleeved on the bottom end of the piston rod. The outer ring surface of the sealing element is in contact with the circumferential inner wall surface of the piston rod assembly cylinder. The sealing element is located between the first piston and the top port of the assembly cylinder and is used to seal the gap between the piston rod and the assembly cylinder.

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