A compression cylinder

Abstract

The application discloses a compression oil cylinder and relates to the technical field of hydraulic oil cylinders.The screw self-locking mechanism driven by a hydraulic motor is integrated in the interior of the device, so that the screw body is driven to rotate synchronously during the movement of the piston body, and the two bodies keep stable cooperative action.When the oil cylinder needs to be locked in the stroke, mechanical self-locking force generated by the screw pair of the screw and the screw sleeve can be used to directly act on the piston body, and the elastic self-locking mechanism can effectively resist the slow movement of the oil cylinder caused by the internal and external leakage of the hydraulic system.Through the mechatronic integrated multiple locking mode, the oil cylinder is provided with the stable and reliable multiple self-locking guarantee beyond the pure hydraulic locking, and the safety and reliability under heavy load and continuous operation are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder technology, and more particularly to a compression cylinder. Background Technology

[0002] Compression cylinders are the core actuators in hydraulic transmission systems. They are widely used in heavy-duty applications such as material compression molding, engineering machinery clamping, and industrial equipment stamping. During operation, compression cylinders typically need to maintain a fixed extension or retraction stroke for extended periods to maintain a stable clamping and compression load. Therefore, cylinder stroke self-locking control is a core control element to ensure continuous and safe operation of the equipment.

[0003] Currently, most mainstream control solutions in the industry rely on closed-loop control logic of hydraulic circuits. This involves locking the oil cylinder's inlet and outlet pipelines through hydraulic valve groups, blocking the flow of oil medium, and limiting the axial displacement of the piston. This achieves passive self-locking of the compression cylinder's working stroke. While this solution meets the load-holding and positioning requirements under normal working conditions, in heavy-load continuous operation scenarios, the compression cylinder's long-term high-load and high-frequency reciprocating operation can easily lead to wear and aging of structures such as the cylinder piston rod sealing components, hydraulic pipeline joints, and control valve cores. This can cause complex oil circuit leakage problems, including internal and external leakage. In this case, simply relying on oil circuit locking control is insufficient to offset the hydraulic medium loss caused by the complex leakage. This can result in slow piston movement, stroke deviation, and a significant decrease in self-locking stability. In severe cases, it can even cause equipment load loss, greatly affecting the safety of equipment operation.

[0004] Therefore, a compression cylinder is proposed to solve some of the problems existing in the above-mentioned prior art. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art where, under heavy-load continuous operation conditions, the compression cylinder cannot maintain a stable stroke by relying solely on the hydraulic oil circuit for locking, which easily leads to piston movement and insufficient self-locking reliability. Therefore, this invention proposes a compression cylinder.

[0006] To address the problems existing in the prior art, the present invention adopts the following technical solution: A compression cylinder includes a cylinder barrel, a base fixedly mounted at the lower end of the cylinder barrel, a piston rod slidably inserted into the cylinder barrel extending to the outer side of its upper end, a piston body slidably mounted in the cylinder barrel and fixedly mounted at the lower end of the piston rod, a rodless chamber located below the piston body and a rod chamber located above the piston body are formed in the cylinder barrel, a first interface communicating with the bottom of the rodless chamber is opened on the base, a second interface communicating with the top of the rod chamber is opened on the cylinder barrel, a screw self-locking mechanism acting on the piston body is integrated in the cylinder barrel, and the screw self-locking mechanism includes a screw sleeve fixedly mounted in the piston body, the piston rod is configured as a hollow structure, a screw body movably inserted into the piston rod is helically screwed into the screw sleeve, and the lower end of the screw body is rotatably connected to the base, a hydraulic motor for driving the screw body to rotate is integrated in the base, the direction and speed of the screw sleeve moving along the screw body are adapted to the direction and speed of the piston body being hydraulically driven, and an elastic self-locking mechanism is integrated on the piston body.

[0007] Preferably, the screw body and the piston rod are arranged parallel to each other, and the axis of the screw body does not coincide with the axis of the piston rod.

[0008] Preferably, the hydraulic motor is connected between the first interface and the bottom of the rodless cavity. The hydraulic motor includes a motor cavity formed in the base, and a first oil passage communicating with the first interface is formed on one side of the inner wall of the motor cavity. A second oil passage communicating with the bottom of the rodless cavity is formed on the other side of the inner wall of the motor cavity. A symmetrically arranged gear is rotatably installed in the motor cavity. The meshing position between the two gears is located between the ports of the first oil passage and the second oil passage. A shaft extending into the rodless cavity is fixedly installed on the axis of one of the gears.

[0009] Preferably, a coupling is installed between the screw body and the shaft, and the upper and lower ends of the coupling are fixedly connected to the lower end of the screw body and the upper end of the shaft, respectively.

[0010] Preferably, the piston body integrates a buffer mechanism that cooperates with the hydraulic motor, and the buffer mechanism includes a first annular groove that is opened around the cylindrical surface of the lower end of the piston body. A valve ring is movably sleeved in the first annular groove, and the valve ring is slidably sealed to the cylindrical surface in the first annular groove and the inner wall of the cylinder. A first spring that is elastically supported on the top of the valve ring is installed in the first annular groove. A plurality of through holes are opened in the piston body that are distributed around the piston body, and the through holes communicate with the bottom of the rod cavity and the interior of the first annular groove.

[0011] Preferably, the elastic self-locking mechanism includes a second annular groove formed around the cylindrical surface of the piston body, and an elastic ring is installed in the second annular groove. The elastic ring is tightly fitted to the cylindrical surface in the second annular groove and the inner wall of the cylinder. A third oil passage and a fourth oil passage are formed in the piston body, which connect the upper and lower sides of the elastic ring in the second annular groove. A bidirectional triggering mechanism that connects to the third oil passage and a reset auxiliary mechanism that connects to the fourth oil passage are integrated in the piston body.

[0012] Preferably, the bidirectional triggering mechanism includes a first chamber vertically formed in the piston body, with a fifth oil passage at the upper end of the first chamber connecting to the bottom of the rod chamber and a sixth oil passage at the lower end of the first chamber connecting to the top of the rodless chamber. A movable block is slidably installed in the first chamber, and a third oil passage connects to the inner wall of the first chamber. A first docking channel and a second docking channel are symmetrically arranged at the upper and lower ends of the movable block, respectively. The first docking channel and the second docking channel are configured as L-shaped structures, and the docking state of the first docking channel and the second docking channel with the third oil passage is switched by sliding the movable block.

[0013] Preferably, the inner wall of the first chamber is configured as a square structure, the outer dimensions of the movable block are adapted to the inner dimensions of the first chamber, a damping fit is formed between the movable block and the first chamber, and the movable block is hydraulically pushed to move up and down in the first chamber for adjustment.

[0014] Preferably, the reset auxiliary mechanism includes a second chamber opened in the piston body, one end of the second chamber is connected to the fourth oil passage, a valve plate adapted to its internal size is slidably installed in the second chamber, and a second spring for elastic support of the valve plate is installed on the side of the second chamber away from the fourth oil passage.

[0015] Preferably, a hydraulic valve assembly is externally connected to both the first and second interfaces, and the hydraulic valve assembly includes a valve body, a valve cavity is opened in the valve body, and a valve core adapted to its internal size is slidably installed in the valve cavity. A third spring for elastic support of the valve core is installed inside one end of the valve cavity. A flow channel perpendicularly communicating with the valve cavity is opened through the valve body. A third interface communicating with the other end of the valve cavity is opened on the valve body. An annular cavity located between the flow channel and the third interface is opened around the cylindrical surface of the valve core. A balance hole communicating with the inside of the valve cavity is opened through the valve body at the end near the third spring.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, by integrating a screw self-locking mechanism driven by a hydraulic motor into the device, the screw body is driven to rotate synchronously during the movement of the piston body, and the two maintain stable cooperative action. When the cylinder needs to lock its stroke, the helical pair of the screw and the sleeve can generate a mechanical self-locking force, which acts directly on the piston body. In conjunction with the elastic self-locking mechanism, it can effectively resist the slow movement of the cylinder caused by internal and external leakage of the hydraulic system. Through this electromechanical-hydraulic integrated multi-locking method, the cylinder can be provided with stable and reliable multi-locking protection that surpasses pure hydraulic locking, which greatly improves the safety and reliability under heavy load and continuous operation. 2. In this invention, by integrating the bidirectional triggering mechanism into the front end of the third oil passage within the elastic self-locking mechanism, the elastic self-locking mechanism can respond promptly to pressure changes in the rodless and rod-side chambers. When leakage occurs after the oil circuit is locked, causing changes in chamber pressure, it automatically drives the elastic ring to undergo radial deformation, further tightening its fit against the inner wall of the cylinder, generating additional frictional locking force. This, in conjunction with the screw self-locking mechanism, achieves a dynamic and adaptively enhanced locking effect to a certain extent, significantly improving the ability of the compression cylinder to maintain its locked state. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a side sectional view of the present invention; Figure 2 For the present invention Figure 1 Enlarged view of point A in the middle; Figure 3 This is a front sectional view of the present invention; Figure 4 For the present invention Figure 3 Enlarged view of point B in the middle; Figure 5 For the present invention Figure 3 Enlarged view of point C in the middle; Figure 6 This is a perspective view of the present invention; Figure 7 For the present invention Figure 6 A breakdown diagram of the middle structure; Figure 8 This is a perspective view of the assembly and connection of the screw body, shaft, and coupling of the present invention. Figure 9 This is an exploded view of the internal structure of the motor cavity of the present invention; Figure 10 This is an exploded view of the buffer mechanism of the present invention; Figure 11 This is a perspective view of the active block of the present invention; Figure 12 This is a front view of the base of the present invention; Figure 13 For the present invention Figure 12 Sectional view at point DD; Figure 14 This is a top view of the base of the present invention; Figure 15 This is a perspective view of the present invention after the hydraulic valve assembly has been installed; Figure 16 This is a cross-sectional view of the hydraulic valve assembly of the present invention; Figure 17 This is an exploded view of the hydraulic valve assembly of the present invention.

[0018] In the picture: 1. Cylinder; 11. Base; 12. Piston rod; 13. Piston body; 14. First port; 15. Second port; 2. Screw sleeve; 21. Screw body; 3. Motor cavity; 31. First oil passage; 32. Second oil passage; 33. Gear; 34. Shaft; 35. Coupling; 4. First annular groove; 41. Valve ring; 42. First spring; 43. Through hole; 5. Second annular groove; 51. Elastic ring; 52. Third oil passage; 53. Fourth oil passage; 6. First chamber; 61. Fifth oil passage; 62. Sixth oil passage; 63. Movable block; 64. First docking channel; 65. Second docking channel; 7. Second chamber; 71. Valve plate; 72. Second spring; 8. Hydraulic valve assembly; 81. Valve body; 82. Valve chamber; 83. Valve core; 84. Third spring; 85. Flow channel; 86. Third interface; 87. Annular cavity; 88. Balance hole. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Example: This example provides a compression cylinder, see [link to example]. Figure 1 - Figure 17 Specifically, the system includes a cylinder 1, a base 11 fixedly mounted at the lower end of the cylinder 1, a piston rod 12 slidably inserted into the cylinder 1 extending to its upper outer side, a piston body 13 slidably mounted and fixedly installed at the lower end of the piston rod 12 within the cylinder 1, a rodless chamber located below the piston body 13 and a rod chamber located above the piston body 13 formed within the cylinder 1, a first interface 14 communicating with the bottom of the rodless chamber on the base 11, and a second interface 15 communicating with the top of the rod chamber on the cylinder 1. The cylinder 1 integrates... There is a screw self-locking mechanism acting on the piston body 13, and the screw self-locking mechanism includes a screw sleeve 2 fixedly installed in the piston body 13. The piston rod 12 is set as a hollow structure. A screw body 21 is screwed into the screw sleeve 2 and is movably inserted in the piston rod 12. The lower end of the screw body 21 is rotatably connected to the base 11. The base 11 integrates a hydraulic motor for driving the screw body 21 to rotate. The direction and speed of the screw sleeve 2 moving along the screw body 21 are adapted to the direction and speed of the piston body 13 being hydraulically driven.

[0021] In this device, the hollow structure inside the piston rod 12 provides through protection and movement space for the screw body 21. During operation, when the piston body 13 is driven to move by the external hydraulic system, the hydraulic motor starts synchronously, driving the screw body 21 to rotate synchronously via the shaft 34. Since the screw sleeve 2 is fixed inside the piston body 13, the rotational motion of the screw is converted into precise linear movement of the screw sleeve 2 and the piston body 13 along the axial direction. Through the linkage control of the hydraulic system and the hydraulic motor, the direction and speed of the piston body 13 being hydraulically driven are consistent with the direction and speed of its movement along the screw body 21 driven by the screw sleeve 2. The motion formed by the movement is completely synchronized, which can ensure the smoothness and stability of the extension and retraction stroke of the piston rod 12 in the device. When the hydraulic system stops, the hydraulic motor stops running synchronously. At this time, the hydraulic motor has no power to drive the screw body 21 to rotate. With the help of the self-locking force formed by the thread engagement between the screw body 21 and the screw sleeve 2, the position of the piston body 13 can be locked, and the stroke of the piston rod 12 can be locked. Under this condition, even if there is leakage in the rod chamber and the rodless chamber, it will not affect the locking of the piston body 13 and the piston rod 12, which improves the stability and safety of the compression cylinder under heavy load continuous operation to a certain extent.

[0022] The piston body 13 integrates an elastic self-locking mechanism, which includes a second annular groove 5 that is opened around the cylindrical surface of the piston body 13, and an elastic ring 51 that is installed in the second annular groove 5. The elastic ring 51 is tightly attached to the cylindrical surface in the second annular groove 5 and the inner wall of the cylinder 1. A third oil passage 52 and a fourth oil passage 53 are opened in the piston body 13, which connect the upper and lower sides of the elastic ring 51 in the second annular groove 5. The piston body 13 integrates a bidirectional triggering mechanism that docks with the third oil passage 52 and a reset auxiliary mechanism that docks with the fourth oil passage 53.

[0023] The piston body 13 is provided with piston ring sealing structures located on the upper and lower sides of the second ring groove 5, so that the rodless chamber and the rod chamber maintain independent sealing, and the independent space formed by the second ring groove 5 and the inner wall of the cylinder 1 maintains stable sealing. In this device, with the cooperation of the bidirectional triggering mechanism and the reset auxiliary mechanism, when the hydraulic oil pressure drops due to leakage, the elastic ring 51 can expand radially outward under the elastic rebound, so that the elastic ring 51 is pressed tightly against the inner wall of the cylinder 1 again, thereby achieving auxiliary locking of the piston body 13.

[0024] In the specific implementation process, such as Figure 3As shown, the screw body 21 and the piston rod 12 are arranged parallel to each other, but the axis of the screw body 21 does not coincide with the axis of the piston rod 12. In this device, by setting the screw body 21 and the piston rod 12 in a parallel but non-coincident layout, the screw body 21, which drives the axial movement of the screw sleeve 2 by rotation, is arranged on one side inside the piston rod 12. After sliding and telescopic cooperation with the piston rod 12 and the piston body 13 in the cylinder 1, it can form a radial rotation restriction on the screw sleeve 2, so that the rotational movement of the screw body 21 cannot drive the screw sleeve 2, the piston rod 12 and the piston body 13 to rotate. It can form an effective anti-rotation constraint on the piston assembly, which helps to ensure that the piston body 13 can only slide purely axially in the cylinder 1. This makes the device smoother and more stable when the screw body 21 rotates, thereby driving the screw sleeve 2 to drive the piston body 13 to move axially.

[0025] In the specific implementation process, such as Figure 2 - Figure 3 , Figure 9 and Figure 13 As shown, the hydraulic motor is connected between the first interface 14 and the bottom of the rodless cavity. The hydraulic motor includes a motor cavity 3 opened in the base 11. A first oil passage 31 communicating with the first interface 14 is opened on one side of the inner wall of the motor cavity 3. A second oil passage 32 communicating with the bottom of the rodless cavity is opened on the other side of the inner wall of the motor cavity 3. A symmetrically arranged gear 33 is rotatably installed in the motor cavity 3. The meshing position between the two gears 33 is located between the ports of the first oil passage 31 and the second oil passage 32. A shaft 34 extending into the rodless cavity is fixedly installed on the axis of one of the gears 33.

[0026] In this device, the hydraulic motor uses a pair of meshing gears 33 as the core drive unit. When hydraulic oil enters from the first interface 14, it enters the motor cavity 3 through the first oil passage 31, directly impacting the meshing area of ​​the two gears 33. Then, it flows into the rodless cavity through the second oil passage 32. During this process, the flow and impact of the hydraulic oil drive the two meshing gears 33 to rotate, thereby rotating the shaft 34. Similarly, when hydraulic oil enters from the second interface 15, the space of the rodless cavity is compressed, causing the hydraulic oil in the rodless cavity to flow in the reverse direction. During this process, the hydraulic oil enters the motor cavity through the second oil passage 32. Inside cavity 3, the meshing area of ​​impact gear 33 drives gear 33 to rotate shaft 34. Then, hydraulic oil is discharged through the connection of first oil passage 31 and first interface 14. By controlling the inlet and outlet of the oil, the rotation direction of screw body 21 is coordinated with the inlet and outlet direction of the oil, and thus maintains a coordinated state with the movement direction of piston body 13. Through this structure, the oil flow in the inlet and outlet oil pipes of the compression cylinder can be directly converted into the power to drive the screw body 21 to rotate, without the need for additional complex control oil circuits. This is conducive to the integration and efficient coordination of the screw self-locking mechanism drive source.

[0027] In the specific implementation process, such as Figure 2 - Figure 3 and Figure 7 - Figure 8 As shown, a coupling 35 is installed between the screw body 21 and the shaft 34, and the upper and lower ends of the coupling 35 are fixedly connected to the lower end of the screw body 21 and the upper end of the shaft 34, respectively. Figure 14 As shown, simply setting the shaft 34 off-axis in the device can restrict radial rotation during the movement control of the screw sleeve 2. In this device, the connection of the coupling 35 not only enables power transmission between the screw body 21 and the shaft 34, but also compensates for minor coaxiality errors between the shaft 34 and the screw body 21 during installation by utilizing the flexible structure within the coupling 35. This helps ensure the smoothness of the rotational power transmission. At the same time, the connection of the coupling 35 can prevent rigid seizing between the hydraulic motor and the screw body 21, which helps improve the stability of the device during long-term operation.

[0028] In the specific implementation process, such as Figure 2 and Figure 10As shown, the piston body 13 integrates a buffer mechanism that cooperates with the hydraulic motor. The buffer mechanism includes a first annular groove 4 that surrounds the cylindrical surface of the lower end of the piston body 13. A valve ring 41 is movably sleeved in the first annular groove 4. The valve ring 41 is slidably sealed to the cylindrical surface in the first annular groove 4 and the inner wall of the cylinder 1. A stable sliding seal is formed between the valve ring 41 and the cylindrical surface in the first annular groove 4 and the inner wall of the cylinder 1 through the piston ring structure. A first spring 42 is installed in the first annular groove 4 and elastically supported on the top of the valve ring 41. A plurality of through holes 43 are provided in the piston body 13, and the through holes 43 connect the bottom of the rod cavity and the interior of the first annular groove 4. A limiting ring for restricting the valve ring 41 from moving further downward is fixedly installed at the lower end of the first annular groove 4.

[0029] In this device, when the piston rod 12 of the compression cylinder is in the retracted state, the valve ring 41 is in the lower position under the oil pressure in the rodless chamber and the elastic support of the first spring 42. The through hole 43 remains unobstructed. The rod chamber is connected to the upper space of the valve ring 41 in the first annular groove 4 through the through hole 43, while the rodless chamber is connected to the lower space of the valve ring 41 in the first annular groove 4. When hydraulic oil enters from the first interface 14, it first drives the gear 33 in the motor chamber 3 to rotate, and then enters the rodless chamber to push the valve ring 41 upward. During this process, the screw body 21 is driven to rotate, and under the connection of the first spring 42, the piston body 13 is pushed upward. Then, the valve ring 41 is pushed to the upper position in the first annular groove 4.

[0030] When hydraulic oil enters from the second port 15, it enters the space above the valve ring 41 in the first annular groove 4 through the through hole 43. Driven by the hydraulic oil, the valve ring 41 is pushed downward. Before the piston body 13 moves, the hydraulic oil in the rodless chamber is compressed, so that the hydraulic oil in the rodless chamber is guided to the motor chamber 3 through the second oil passage 32, driving the gear 33 to rotate and drive the screw body 21 to rotate. After the rotation restriction of the screw body 21 is released, the hydraulic oil acting on the piston body 13 and the valve ring 41 can drive them to move downward smoothly. During the retraction stroke of the piston rod 12, the prior drive of the valve ring 41 can drive the hydraulic motor to start synchronously, realizing buffer release. This helps to ensure that the hydraulic motor can start and run smoothly during the extension and retraction strokes, and to a certain extent improves the operational stability of the device in actual use.

[0031] In the specific implementation process, such as Figure 3 and Figure 4As shown, the bidirectional triggering mechanism includes a first chamber 6 vertically formed within the piston body 13. The upper end of the first chamber 6 has a fifth oil passage 61 connecting to the bottom of the rod chamber, and the lower end of the first chamber 6 has a sixth oil passage 62 connecting to the top of the rodless chamber. A movable block 63 is slidably installed within the first chamber 6. A third oil passage 52 connects to the inner wall of the first chamber 6. The movable block 63 has a first docking channel 64 and a second docking channel 65 symmetrically arranged at its upper and lower ends. The first docking channel 64 and the second docking channel 65 are L-shaped. The docking state of the first docking channel 64 and the second docking channel 65 with the third oil passage 52 is switched by sliding the movable block 63. One end of the first docking channel 64 is located at the top of the movable block 63, and the other end is located on the side wall of the movable block 63. One end of the second docking channel 65 is located at the bottom of the movable block 63, and the other end is located on the side wall of the movable block 63.

[0032] In this device, during the extension stroke control process, the elastic self-locking mechanism can be flexibly controlled through a bidirectional triggering mechanism. When the rodless chamber is filled with oil and pushes the piston body 13 upward, the high-pressure hydraulic oil enters the bottom of the first chamber 6 through the sixth oil passage 62, pushing the movable block 63 upward, so that the side opening of the second docking channel 65 is aligned with the third oil passage 52, thereby introducing the high-pressure oil in the rodless chamber into the third oil passage 52 and reaching the upper side of the elastic ring 51 in the second annular groove 5. With the continuous injection of high-pressure hydraulic oil, the hydraulic oil fills the space between the inner wall of the cylinder 1 and the elastic ring 51 in the second annular groove 5, driving the elastic ring 51 to contract radially towards the axial direction. In this case, the outer wall of the elastic ring 51 is no longer tightly attached to the inner wall of the cylinder 1, releasing the locking of the piston body 13.

[0033] Similarly, when the rod chamber is filled with oil and pushes the piston body 13 downward, the high-pressure hydraulic oil enters the top of the first chamber 6 through the fifth oil passage 61, pushing the movable block 63 downward, so that the side opening of the first docking channel 64 is aligned with the third oil passage 52, thereby introducing the high-pressure oil in the rod chamber into the third oil passage 52, reaching the upper side of the elastic ring 51 in the second annular groove 5, maintaining the unlocked state of the piston body 13. When the rodless or rod chamber leaks during the extension stroke, causing the hydraulic oil pressure to drop, the elastic ring 51 expands radially outward and rebounds to reset under the elastic rebound, discharging the hydraulic oil between the inner wall of the cylinder 1 and the elastic ring 51, so that the elastic ring 51 is pressed tightly against the inner wall of the cylinder 1 again, realizing the auxiliary locking of the piston body 13. Through the cooperation of the elastic self-locking mechanism and the screw self-locking mechanism, a multi-locking electromechanical-hydraulic system can be formed, which is conducive to providing stable and reliable multi-locking protection for the compression cylinder, and further improving the safety and reliability of the compression cylinder under heavy load and continuous operation.

[0034] In the specific implementation process, such as Figure 4 and Figure 11 As shown, the inner wall of the first chamber 6 is set as a square structure, and the outer dimensions of the movable block 63 are adapted to the inner dimensions of the first chamber 6. A damping fit is formed between the movable block 63 and the first chamber 6. The movable block 63 is hydraulically pushed to move up and down in the first chamber 6 for adjustment. In this device, by forming a square structure between the movable block 63 and the first chamber 6 and performing a damping fit, it can be ensured that the movable block 63 will not rotate or shake arbitrarily due to hydraulic oil disturbance. This allows the movable block 63 to slide stably up and down only under the hydraulic thrust of the hydraulic oil, which facilitates precise control of the alignment state of the first docking channel 64, the second docking channel 65 and the third oil passage 52, and is conducive to achieving reliable switching of the oil circuit direction.

[0035] In the specific implementation process, such as Figure 5 As shown, the reset auxiliary mechanism includes a second chamber 7 formed within the piston body 13, with one end of the second chamber 7 connected to the fourth oil passage 53. A valve plate 71, adapted to its internal dimensions, is slidably installed within the second chamber 7. A second spring 72, providing elastic support for the valve plate 71, is installed on the side of the second chamber 7 away from the fourth oil passage 53. In this device, the second spring 72 within the reset auxiliary mechanism can provide preload force to the valve plate 71. When high-pressure hydraulic oil enters the second annular groove 5 through the third oil passage 52, it pushes open and fills the inner wall of the cylinder 1 and the elastic ring. When the pressure is between 51 and 52, excess hydraulic oil can overcome the elastic support of the second spring 72 and push the valve plate 71 to temporarily exist in the second chamber 7. When hydraulic oil leakage causes insufficient oil pressure in the third oil passage 52, the pushing of the second spring 72 can ensure that excess hydraulic oil exits in time from between the inner wall of the cylinder 1 and the elastic ring 51. By connecting the second chamber 7 with the fourth oil passage 53, a stable pressure difference can be formed on the upper and lower sides of the elastic ring 51 in the second annular groove 5, which is conducive to the auxiliary elastic self-locking mechanism to complete the switching and reset of the working state.

[0036] In the specific implementation process, such as Figure 15 - Figure 17As shown, both the first interface 14 and the second interface 15 are externally connected to a hydraulic valve assembly 8. The hydraulic valve assembly 8 includes a valve body 81, a valve cavity 82 is formed inside the valve body 81, and a valve core 83 adapted to its internal dimensions is slidably installed inside the valve cavity 82. A third spring 84 for elastic support of the valve core 83 is installed inside one end of the valve cavity 82. A flow channel 85 perpendicularly communicating with the valve cavity 82 is formed through the valve body 81. A third interface 86 communicating with the other end of the valve cavity 82 is formed on the valve body 81. The valve core 83... A ring cavity 87 is formed around the cylindrical surface between the flow channel 85 and the third interface 86. A balance hole 88 is formed at the end of the valve body 81 near the third spring 84 and communicates with the inside of the valve cavity 82. In the two hydraulic valve groups 8, one end of the flow channel 85 in one hydraulic valve group 8 is fixedly connected to the first interface 14, and one end of the flow channel 85 in the other hydraulic valve group 8 is fixedly connected to the second interface 15. The other ends of the two flow channels 85 are externally connected to a hydraulic system, and the two flow channels 85 are externally connected to another hydraulic pipeline.

[0037] In this device, the external hydraulic valve assembly 8 can provide system-level locking and protection. When it is necessary to lock the compression cylinder, the external control system can supply control oil pressure to the third interface 86 within the two hydraulic valve assemblies 8, pushing the valve core 83 to compress the third spring 84, causing the annular cavity 87 on the valve core 83 to connect with the flow channel 85, thereby connecting the first interface 14, the second interface 15, and the oil circuit of the external hydraulic system. When the control system connected to the third interface 86 depressurizes, the elastic reset of the third spring 84 drives the annular cavity 87 to re-disconnect from the two ends of the flow channel 85, thus reconnecting the two ends of the flow channel 85. The first interface 14, the second interface 15 and the external hydraulic system oil circuit are closed and pressure is maintained. During operation, the opening of the balance hole 88 can ensure that the cavity on the third spring 84 side is always balanced with the ambient pressure, avoiding the formation of back pressure that affects the action sensitivity of the valve core 83. The device can form the first locking defense line at the hydraulic level through the above two hydraulic valve groups 8. After cooperating with the screw self-locking mechanism and the elastic self-locking mechanism, a multi-locking structure can be further formed, which is conducive to more stably realizing the locking of the compression cylinder action stroke under complex leakage conditions, and further improving the safety of the device during continuous load operation.

[0038] Specifically, the working principle of this invention is as follows: During operation, hydraulic oil flows through the flow channel 85 of the external hydraulic valve group 8, enters the rodless chamber through the first interface 14, or enters the rod chamber through the second interface 15, driving the piston body 13 and piston rod 12 to perform extension or retraction actions. During this process, the hydraulic oil flowing through the hydraulic motor in the base 11 drives a pair of gears 33 to rotate, which in turn drives the screw body 21 to rotate synchronously through the shaft 34 and the coupling 35. Since the screw sleeve 2 is fixed inside the piston body 13, and the axis of the screw body 21 is parallel to but does not coincide with the piston rod 12, an anti-rotation constraint can be formed. Therefore, the rotation of the screw can be accurately converted into the linear motion of the piston assembly along the axial direction. At this stage, hydraulic drive is the main method, and the screw mechanism follows and synchronizes in a seamless and coordinated manner. When it is necessary to lock the cylinder stroke, the two hydraulic valve groups 8 First, triggered by the elastic support of the third spring 84, the valve core 83 is pushed to block the flow channel 85, achieving the first-stage hydraulic oil circuit lock-up. Inside the compression cylinder, the threaded engagement between the screw sleeve 2 and the screw body 21 achieves stepless self-locking of the piston rod 12 and piston body 13. Simultaneously, when hydraulic oil leakage occurs, the pressure loss causes the elastic ring 51 to deform radially, tightly adhering to the inner wall of the cylinder 1, generating a huge additional static friction force. Through the external hydraulic valve group 8, oil circuit lock-up is achieved; through the integrated screw self-locking mechanism, mechanical lock-up is achieved; and through the built-in elastic self-locking mechanism, intelligent auxiliary lock-up is achieved. This forms a three-level coordinated locking structure, with active control and automatic triggering working together to effectively construct a progressive and mutually backup adaptive locking system.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A compression cylinder, comprising a cylinder barrel (1), characterized in that: A base (11) is fixedly installed at the lower end of the cylinder (1). A piston rod (12) extending to the outer side of its upper end is slidably inserted into the cylinder (1). A piston body (13) is slidably installed and fixedly installed at the lower end of the piston rod (12) inside the cylinder (1). A rodless cavity located below the piston body (13) and a rod cavity located above the piston body (13) are formed inside the cylinder (1). A first interface (14) communicating with the bottom of the rodless cavity is opened on the base (11). A second interface (15) communicating with the top of the rod cavity is opened on the cylinder (1). A screw self-locking mechanism acting on the piston body (13) is integrated inside the cylinder (1), and the screw is self-locking. The mechanism includes a screw sleeve (2) fixedly installed inside the piston body (13). The piston rod (12) is configured as a hollow structure. A screw body (21) is screwed into the screw sleeve (2) and is movably inserted into the piston rod (12). The lower end of the screw body (21) is rotatably connected to the base (11). The base (11) integrates a hydraulic motor for driving the screw body (21) to rotate. The hydraulic motor is connected between the first interface (14) and the bottom of the rodless cavity. The direction and speed of the screw sleeve (2) moving along the screw body (21) are adapted to the direction and speed of the piston body (13) being hydraulically driven. The piston body (13) integrates an elastic self-locking mechanism. The piston body (13) is integrated with a buffer mechanism that cooperates with the hydraulic motor. The buffer mechanism includes a first annular groove (4) that is opened around the cylindrical surface of the lower end of the piston body (13). A valve ring (41) is movably sleeved in the first annular groove (4). The valve ring (41) is slidably sealed to the cylindrical surface in the first annular groove (4) and the inner wall of the cylinder (1). A first spring (42) that is elastically supported on the top of the valve ring (41) is installed in the first annular groove (4). A plurality of through holes (43) are opened in the piston body (13) that are distributed around it. The through holes (43) connect the bottom of the rod cavity and the interior of the first annular groove (4). The elastic self-locking mechanism includes a second annular groove (5) that is opened around the cylindrical surface of the piston body (13), and an elastic ring (51) is installed in the second annular groove (5). The elastic ring (51) is tightly attached to the cylindrical surface in the second annular groove (5) and the inner wall of the cylinder (1). A third oil passage (52) and a fourth oil passage (53) are opened in the piston body (13) to connect the upper and lower sides of the elastic ring (51) in the second annular groove (5). A bidirectional triggering mechanism that connects to the third oil passage (52) and a reset auxiliary mechanism that connects to the fourth oil passage (53) are integrated in the piston body (13). The bidirectional triggering mechanism includes a first chamber (6) vertically opened in the piston body (13), and a fifth oil passage (61) connected to the bottom of the rod chamber is opened at the upper end of the first chamber (6), and a sixth oil passage (62) connected to the top of the rodless chamber is opened at the lower end of the first chamber (6). A movable block (63) is slidably installed in the first chamber (6), and the third oil passage (52) is connected to the inner wall of the first chamber (6). A first docking channel (64) and a second docking channel (65) symmetrically arranged are opened at the upper and lower ends of the movable block (63). The first docking channel (64) and the second docking channel (65) are set in an L-shaped structure. The docking state of the first docking channel (64) and the second docking channel (65) with the third oil passage (52) is switched by sliding the movable block (63). The inner wall of the first chamber (6) is set as a square structure. The outer dimensions of the movable block (63) are adapted to the inner dimensions of the first chamber (6). A damping fit is formed between the movable block (63) and the first chamber (6). The movable block (63) is hydraulically pushed to move up and down in the first chamber (6) for adjustment.

2. A compression cylinder according to claim 1, characterized in that: The screw body (21) and the piston rod (12) are arranged parallel to each other, and the axis of the screw body (21) does not coincide with the axis of the piston rod (12).

3. A compression cylinder according to claim 1, characterized in that: The hydraulic motor includes a motor cavity (3) opened in the base (11), and a first oil passage (31) communicating with the first interface (14) is opened on one side of the inner wall of the motor cavity (3). A second oil passage (32) communicating with the bottom of the rodless cavity is opened on the other side of the inner wall of the motor cavity (3). A symmetrically arranged gear (33) is rotatably installed in the motor cavity (3). The meshing position between the two gears (33) is located between the ports of the first oil passage (31) and the second oil passage (32). A shaft (34) extending into the rodless cavity is fixedly installed on the axis of one of the gears (33).

4. A compression cylinder according to claim 3, characterized in that: A coupling (35) is installed between the screw body (21) and the shaft (34), and the upper and lower ends of the coupling (35) are fixedly connected to the lower end of the screw body (21) and the upper end of the shaft (34), respectively.

5. A compression cylinder according to claim 1, characterized in that: The reset auxiliary mechanism includes a second chamber (7) opened in the piston body (13), and one end of the second chamber (7) is connected to the fourth oil passage (53). A valve plate (71) adapted to its internal size is slidably installed in the second chamber (7). A second spring (72) for elastic support of the valve plate (71) is installed on the side of the second chamber (7) away from the fourth oil passage (53).

6. A compression cylinder according to claim 1, characterized in that: Hydraulic valve assembly (8) is externally connected to both the first interface (14) and the second interface (15), and the hydraulic valve assembly (8) includes a valve body (81). A valve cavity (82) is opened in the valve body (81), and a valve core (83) adapted to its internal size is slidably installed in the valve cavity (82). A third spring (84) for elastic support of the valve core (83) is installed inside one end of the valve cavity (82). A flow channel (85) perpendicularly communicating with the valve cavity (82) is opened through the valve body (81). A third interface (86) communicating with the other end of the valve cavity (82) is opened on the valve body (81). An annular cavity (87) located between the flow channel (85) and the third interface (86) is opened around the cylindrical surface of the valve core (83). A balance hole (88) communicating with the inside of the valve cavity (82) is opened through the end of the valve body (81) near the third spring (84).

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