Bundled multi-stage sequential telescopic oil cylinder with buffering and damping characteristics

Abstract

The utility model provides a binding type multi-stage sequential telescopic oil cylinder with buffering and damping characteristics, and belongs to the technical field of overhead working trucks and hoisting, the binding type multi-stage sequential telescopic oil cylinder comprises at least one first-stage oil cylinder and a second-stage oil cylinder, the first-stage oil cylinder comprises a first cylinder barrel and a first piston rod, and the second-stage oil cylinder comprises a second cylinder barrel and a second piston rod; one end of the first cylinder barrel is connected with a second rod head of the second piston rod through a bearing plate and a pin shaft, and the other end of the first cylinder barrel is slidably connected with the second cylinder barrel through a sliding block. A rod cavity of the first-stage oil cylinder is communicated with a rod cavity of the second-stage oil cylinder through a first oil pipe, and a rodless cavity of the first-stage oil cylinder is communicated with a rodless cavity of the second-stage oil cylinder through a second oil pipe. The end, close to the rodless cavity, of the first piston rod is provided with a first buffering sleeve, and the end, close to the rodless cavity, of the second piston rod is provided with a second buffering sleeve. According to the binding type multi-stage sequential telescopic oil cylinder with the buffering damping characteristic, accurate sequential stretching is achieved, the oil cylinder runs smoothly, the piston rod is prevented from impacting the cylinder barrel, and internal leakage of the oil cylinder is reduced.

Description

Technical Field

[0001] This disclosure relates to the fields of aerial work platforms and lifting and hoisting technology, and in particular to a multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics. Background Technology

[0002] With the increasing application of truck-mounted cranes in industrial handling, gas transportation, and construction, as well as the growing demand from other lifting and hoisting industries that require multi-stage telescopic booms, such as aerial work platforms, the motion sequence logic and stability of multi-stage telescopic cylinders, the reliability and fatigue strength of the products themselves, and energy conservation are all issues that involve personnel safety, operational comfort, and energy consumption requirements.

[0003] In existing technologies, one way to implement sequential logic is through sequence valves. However, this requires significant pressure loss in multi-stage applications, leading to inefficiency, and the sequential logic may malfunction due to load variations. Another method is to use limit switches in the form of spool valves. However, since spool valves generally have some internal leakage, long-term operation will cause multi-stage cylinders to fail to operate in a strictly sequential manner.

[0004] Therefore, existing multi-stage sequential telescopic hydraulic cylinders need to be improved. Utility Model Content

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics, which achieves accurate sequential telescopic movement, smooth cylinder operation, avoids vibration and damage caused by piston rod impacting cylinder barrel, and reduces internal leakage of the hydraulic cylinder.

[0006] To achieve the aforementioned objectives of this utility model, the present disclosure adopts the following technical solution:

[0007] A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics includes at least one primary hydraulic cylinder and one secondary hydraulic cylinder. The primary hydraulic cylinder includes a first cylinder barrel and a first piston rod, and the secondary hydraulic cylinder includes a second cylinder barrel and a second piston rod.

[0008] One end of the first cylinder is connected to the second rod head of the second piston rod via a support plate and a pin, and the other end of the first cylinder is slidably connected to the second cylinder via a slider.

[0009] The rod chamber of the first-stage hydraulic cylinder and the rod chamber of the second-stage hydraulic cylinder are connected by a first oil pipe, and the rodless chamber of the first-stage hydraulic cylinder and the rodless chamber of the second-stage hydraulic cylinder are connected by a second oil pipe;

[0010] A first buffer sleeve is provided at the end of the first piston rod near the rodless cavity, and a second buffer sleeve is provided at the end of the second piston rod near the rodless cavity.

[0011] In an exemplary embodiment of this disclosure, the first cylinder and the second cylinder respectively include a cylinder head, a cylinder tube, and a cylinder bottom arranged sequentially;

[0012] A cylinder body flange is fitted onto the cylinder head, and a U-shaped opening is provided between the cylinder body flange and the cylinder tube. The cylinder body flange and the cylinder tube are connected by welding within the U-shaped opening.

[0013] The width of the cylinder flange of the first-stage hydraulic cylinder is greater than the width of the support plate.

[0014] In one exemplary embodiment of this disclosure, the first piston rod includes a first rod body, a first rod head, and a first piston;

[0015] One end of the first rod extends out of the first cylinder and connects to the first rod head. The other end of the first rod is fitted with the first piston. A support sleeve is provided at the end of the first piston away from the first rod, and the first buffer sleeve is fitted on the support sleeve.

[0016] In one exemplary embodiment of this disclosure, the first rod is a hollow structure;

[0017] The first rod body is provided with a core tube, the core tube is provided with a core cylinder, one end of the core cylinder is provided with a first contact element, and the other end of the core cylinder extends out of the core cylinder and passes through the first piston and the support sleeve in sequence.

[0018] The cylinder bottom is provided with a first cavity that communicates with the rodless chamber of the first-stage oil cylinder. The first cavity is connected to the second oil pipe. A support sleeve, a first spring, and a first cone valve core are arranged in sequence in the first cavity. The other end of the core cylinder passes through the support sleeve, the first spring, and the first cone valve core in sequence and is connected to the locking sleeve. The support sleeve is fixedly connected to the cylinder bottom, and the first cone valve core abuts against the locking sleeve.

[0019] In one exemplary embodiment of this disclosure, a second cavity is provided below the first cavity, and the second cavity is connected to the first cavity and the rodless cavity of the first-stage hydraulic cylinder, respectively.

[0020] A mounting sleeve is provided at one end of the second cavity, and a second cone valve core is provided at the other end of the second cavity. A second spring is provided inside the mounting sleeve, and one end of the second spring extends out of the mounting sleeve and connects to the second cone valve core. The second cone valve core can reciprocate within the second cavity.

[0021] One end of the valve core of the second cone valve extends out of the cylinder bottom and contacts the second contact member, which is disposed on the cylinder bottom of the second cylinder.

[0022] In one exemplary embodiment of this disclosure, the second piston rod further includes a second rod body and a second piston;

[0023] One end of the second rod extends out to connect with the second cylinder and the second rod head. The other end of the second rod is fitted with the second piston. A buffer sleeve is provided at the end of the second piston away from the second rod, and the second buffer sleeve is fitted on the buffer sleeve.

[0024] In one exemplary embodiment of this disclosure, the second rod is a hollow structure;

[0025] The first oil pipe is disposed in the second rod body, and one end of the first oil pipe extends into the second piston and is welded to a threaded connector.

[0026] In one exemplary embodiment of this disclosure, a slider is provided on the side wall of the other end of the first cylinder near the second cylinder. The slider is made of a self-lubricating material, and the slider is connected to the first cylinder by screws. The slider is in contact with the outer wall of the second cylinder.

[0027] An oil filling cup is provided on one side wall of the slider, and an oil delivery groove is provided on the side wall of the slider near the second cylinder. The oil filling cup and the oil delivery groove are connected through an oil delivery hole.

[0028] In an exemplary embodiment of this disclosure, the cylinder head is provided with a first step and a second step at one end near the cylinder tube, and an O-ring is provided between the first step and the second step. The outer diameter of the first step is larger than the outer diameter of the second step.

[0029] A sealant is provided between the end of the cylinder flange away from the cylinder tube and the cylinder head.

[0030] In one exemplary embodiment of this disclosure, both the first buffer sleeve and the second buffer sleeve are made of ORKOT-TLM material.

[0031] The beneficial effects of this utility model are:

[0032] (1) In this utility model, the cylinder flange and the cylinder tube are connected by U-shaped welded joint, which avoids shape error caused by large cylinder deformation and improves the welding quality and fatigue life of the cylinder flange and the cylinder tube.

[0033] (2) In this utility model, the first-stage oil cylinder and the second-stage oil cylinder are connected by sliding transmission through a slider, which eliminates the unstable phenomena such as low-speed movement and creep of the first-stage oil cylinder and the second-stage oil cylinder, and ensures the smooth operation of the two oil cylinders.

[0034] (3) This utility model uses two limit switches for sequential logic control to achieve accurate sequential extension and retraction, improve the reliability of multi-stage sequential extension and retraction cylinder operation, and reduce the energy loss of cylinder operation.

[0035] (4) This utility model uses a cone valve core to seal by hydraulic locking, avoiding the risk of increased leakage due to wear of the slide valve structure in the later stage, reducing the internal leakage of the multi-stage telescopic cylinder, and using a long-stroke spring to cooperate with the movement of the valve to compensate for the influence of dimensional errors generated by the cylinder stroke and other links on the limit switch.

[0036] (5) The present invention installs a buffer sleeve at the end of the piston rod stroke extension, and uses its own elasticity and damping characteristics to prevent the rod or piston from directly hitting the bottom of the cylinder and causing vibration and damage.

[0037] (6) In this utility model, the cylinder head static sealing O-ring groove adopts a double-step height to improve the process performance of the cylinder head. The sealant between the cylinder head and the cylinder body flange is applied to waterproof the cylinder, thereby preventing external water from entering the cylinder and preventing high pressure buildup inside the cylinder. Attached Figure Description

[0038] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0039] Figure 1 This is a front view of a bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics in one embodiment of the present disclosure.

[0040] Figure 2 This is a front sectional view of a bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics in one embodiment of the present disclosure.

[0041] Figure 3 This is a top view of a bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics in one embodiment of the present disclosure.

[0042] Figure 4 This is a top sectional view of a bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics in one embodiment of the present disclosure.

[0043] Figure 5 This is a schematic diagram of the slider structure in one embodiment of the present disclosure;

[0044] Figure 6 This is an installation diagram of the first cone valve core and the second cone valve core in one embodiment of the present disclosure;

[0045] Figure 7 This is an assembly diagram of the cylinder head and cylinder block flange in one embodiment of the present disclosure.

[0046] Explanation of reference numerals in the attached figures:

[0047] 1. First-stage hydraulic cylinder; 2. Second-stage hydraulic cylinder; 3. First cylinder barrel; 4. First piston rod; 5. Second cylinder barrel; 6. Second piston rod; 7. Support plate; 8. Pin; 9. Second rod head; 10. Slider; 11. First oil pipe; 12. Second oil pipe; 13. First buffer sleeve; 14. Second buffer sleeve; 15. Cylinder head; 16. Cylinder tube; 17. Cylinder bottom; 18. Cylinder body flange; 19. U-shaped cut; 20. First rod body; 21. First rod head; 22. First piston; 23. 24. Support sleeve; 25. Core tube; 26. Core cylinder; 27. First contact element; 28. Locking sleeve; 29. ​​Support sleeve; 30. First cone valve core; 31. Mounting sleeve; 32. Second cone valve core; 33. Second spring; 34. Second rod; 35. Second piston; 36. Buffer lock sleeve; 37. Threaded connector; 38. Oil cup; 39. Oil delivery groove; 40. First step; 41. Second step; 42. O-ring seal; 43. Second contact element. Detailed Implementation

[0048] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0049] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0050] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0051] This disclosure provides a bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics. See also... Figures 1 to 4 The system includes at least one primary cylinder 1 and one secondary cylinder 2. The primary cylinder 1 includes a first cylinder barrel 3 and a first piston rod 4, and the secondary cylinder 2 includes a second cylinder barrel 5 and a second piston rod 6. One end of the first cylinder barrel 3 is connected to the second rod head 9 of the second piston rod 6 through a support plate 7 and a pin 8, and the other end of the first cylinder barrel 3 is slidably connected to the second cylinder barrel 5 through a slider 10. The rod chamber of the primary cylinder 1 and the rod chamber of the secondary cylinder 2 are connected through a first oil pipe 11, and the rodless chamber of the primary cylinder 1 and the rodless chamber of the secondary cylinder 2 are connected through a second oil pipe 12. A first buffer sleeve 13 is provided at the end of the first piston rod 4 near the rodless chamber, and a second buffer sleeve 14 is provided at the end of the second piston rod 6 near the rodless chamber.

[0052] In this embodiment, the multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics consists of at least one primary cylinder 1 and one secondary cylinder 2. The primary cylinder 1 comprises a first cylinder 3 and a first piston rod 4 installed within the first cylinder 3. The secondary cylinder 2 comprises a second cylinder 5 and a second piston rod 6 installed within the second cylinder 5. A first buffer sleeve 13 is mounted on the first piston rod 4, and a second buffer sleeve 14 is mounted on the second piston rod 6. One end of the first cylinder 3 is connected to the second rod head 9 of the second piston rod 6 via a support plate 7 and a pin 8. The outer wall of the other end of the first cylinder 3 is slidably connected to the outer wall of the other end of the second cylinder 5 via a slider 10, thereby binding the primary cylinder 1 and the secondary cylinder 2 together. The primary cylinder 1 has a rod... The rodless chamber of the first-stage cylinder 1 is connected to the rod-side chamber of the second-stage cylinder 2 via a first oil pipe 11, and the rodless chamber of the first-stage cylinder 1 is connected to the rodless chamber of the second-stage cylinder 2 via a second oil pipe 12. When the oil flows into the rodless chamber of the first-stage cylinder 1, the first cylinder 3 of the first-stage cylinder 1 drives the second-stage cylinder 2 to extend outward. When the stroke of the first cylinder 3 ends, the oil flows into the rodless chamber of the second-stage cylinder 2, and the second cylinder 5 slides outward on the slider 10, thus achieving sequential extension. When the oil flows into the rod-side chamber of the second-stage cylinder 2, the second cylinder 5 retracts inward on the slider 10. When the stroke of the second cylinder 5 ends, the oil in the rodless chamber of the first-stage cylinder 1 flows out, and the first cylinder 3 retracts, thus achieving sequential retraction. The first cylinder 3 and the second cylinder 5 retract smoothly via the first buffer sleeve 13 and the second buffer sleeve 14, respectively.

[0053] Compared to existing multi-stage sequential telescopic cylinders, this bundled multi-stage sequential telescopic cylinder with buffer damping characteristics can achieve accurate sequential telescopic movement, improve the reliability of multi-stage sequential telescopic cylinder operation, and reduce energy loss during cylinder operation. The sliding transmission between the first-stage and second-stage cylinders is achieved through a slider, eliminating unstable phenomena such as low-speed creep between the first-stage and second-stage cylinders and ensuring smooth relative operation of the two cylinders. By installing a buffer sleeve at the end of the piston rod's stroke extension, its elasticity and damping characteristics are utilized to prevent the rod or piston from directly impacting the cylinder bottom, thus avoiding vibration and damage.

[0054] In one embodiment of this disclosure, when there is only one primary hydraulic cylinder 1, the multi-stage sequential telescopic hydraulic cylinder is a secondary telescopic hydraulic cylinder, and the secondary hydraulic cylinder 2 is located below the primary hydraulic cylinder 1.

[0055] It is understood that the binding type two-stage sequential telescopic hydraulic cylinder of this utility model can be extended to a three-stage or higher structure, that is, multiple first-stage hydraulic cylinders 1 can be added between the first-stage hydraulic cylinder 1 and the second-stage hydraulic cylinder 2.

[0056] In one embodiment of this disclosure, see Figure 4 There are two support plates 7, and the bottom ends of the two support plates 7 are connected by a connecting plate. The second rod head 9 is located between the two support plates 7 and above the connecting plate. The second rod head 9 is connected to the two support plates 7 by a pin 8.

[0057] In one embodiment of this disclosure, see Figure 2 The first cylinder 3 and the second cylinder 5 each include a cylinder head 15, a cylinder tube 16, and a cylinder bottom 17 arranged sequentially. A cylinder flange 18 is fitted onto the cylinder head 15, and a U-shaped notch 19 is provided between the cylinder flange 18 and the cylinder tube 16. The cylinder flange 18 and the cylinder tube 16 are connected by welding within the U-shaped notch 19. This improves the welding quality and fatigue life of the cylinder flange and the cylinder tube.

[0058] Optionally, see Figure 2 The width of the cylinder flange 18 of the first-stage cylinder 1 is greater than the width of the support plate 7. This avoids machining interference between the first-stage cylinder 1 and the second-stage cylinder 2, and facilitates the telescopic movement of the first-stage cylinder 1 and the second-stage cylinder 2.

[0059] Optionally, clearance spaces are provided at both ends of the support plate 7 on the side closest to the first cylinder 3. This avoids machining interference between the support plate 7 and the cylinder flange 18, facilitating the installation of the support plate 7 on the cylinder flange 18.

[0060] Optionally, a clearance space is provided between the end of the support plate 7 near the second cylinder 5 and the end of the second rod head 9 near the second cylinder 5. This avoids machining interference between the support plate 7 and the second rod head 9, facilitating the installation of the second rod head 9 on the support plate 7.

[0061] In one embodiment of this disclosure, during the machining of the inner walls of the first cylinder 3 and the second cylinder 5, 1-2 mm of the bottom of the weld bead of the first cylinder 3 and the second cylinder 5 is removed. This reduces welding defects inside the weld bead and minimizes shape errors caused by large deformation of the cylinder due to the large heat-affected zone of the welded parts on the outer wall of the cylinder.

[0062] In one embodiment of this disclosure, see Figure 2 The first piston rod 4 includes a first rod body 20, a first rod head 21, and a first piston 22. One end of the first rod body 20 extends out of the first cylinder 3 and connects to the first rod head 21. The other end of the first rod body 20 is fitted with the first piston 22. A support sleeve 23 is provided at the end of the first piston 22 away from the first rod body 20, and a first buffer sleeve 13 is fitted on the support sleeve 23. In this way, the first buffer sleeve 13 can be installed at the end of the first piston rod 4 near the rodless chamber, thereby preventing the first piston rod 4 from directly impacting the cylinder bottom 17 and causing vibration and damage when moving in the first cylinder 3. At the same time, it avoids the defects of using a throttling method that require multiple tests and is greatly affected by oil temperature.

[0063] Optionally, the first buffer sleeve 13 is made of ORKOT-TLM material. The first buffer sleeve 13 has high strength and good elasticity and damping, which improves the buffering effect of the first buffer sleeve 13.

[0064] It is understandable that the first buffer sleeve 13 is fitted on the support sleeve 23. The contact area between the first buffer sleeve 13 and the cylinder bottom 17 is small, which avoids the problem of excessive starting pressure or inability to start the first stage oil cylinder 1.

[0065] It is understandable that the thickness of the first buffer sleeve 13 can be designed according to the damping and elasticity requirements of the first-stage hydraulic cylinder 1.

[0066] In one embodiment of this disclosure, see Figure 2 and Figure 6The first rod body 20 is a hollow structure; a core tube 24 is provided inside the first rod body 20, and a core cylinder 25 is provided inside the core tube 24. A first contact element 26 is provided at one end of the core cylinder 25, and the other end of the core cylinder 25 extends out of the core cylinder 25 and passes through the first piston 22 and the support sleeve 23 in sequence; a first cavity is provided in the cylinder bottom 17, which is connected to the rodless chamber of the first stage oil cylinder 1. The first cavity is connected to the second oil pipe 12. A support sleeve 28, a first spring 29 and a first cone valve core 30 are arranged in sequence in the first cavity. The other end of the core cylinder 25 passes through the support sleeve 28, the first spring 29 and the first cone valve core 30 in sequence and is connected to the locking sleeve 27. The support sleeve 28 is fixedly connected to the cylinder bottom 17, and the first cone valve core 30 abuts against the locking sleeve 27. Thus, the first limit switch is formed by the first contact element 26, the locking sleeve 27, the first spring 29, and the first cone valve core 30. The first limit switch enables the rodless chamber of the second-stage cylinder 2 to be connected after the first-stage cylinder 1 reaches its stroke, thereby realizing the sequential extension and retraction of the multi-stage sequential cylinder.

[0067] It is understandable that the first rod head 21 is provided with two oil supply channels, one of which is connected to the core tube 24 and the other is connected to the first rod body 20.

[0068] In one embodiment of this disclosure, see Figure 2 and Figure 6 A second cavity is provided below the first cavity, and the second cavity is connected to both the first cavity and the rodless cavity of the first-stage cylinder 1. A mounting sleeve 31 is provided at one end of the second cavity, and a second cone valve core 32 is provided at the other end. A second spring 33 is provided inside the mounting sleeve 31, with one end of the second spring 33 extending out of the mounting sleeve 31 and connecting to the second cone valve core 32. The second cone valve core 32 can reciprocate within the second cavity. One end of the second cone valve core 32 extends out of the cylinder bottom 17 and contacts a second contact element 43, which is located on the cylinder bottom 17 of the second cylinder 5. Thus, the second cone valve core 32, the second spring 33, and the second contact element 43 form a second limit switch. This second limit switch enables the connection to the rodless cavity of the first-stage cylinder 1 to be restored when the second-stage cylinder 2 is fully retracted, and to be closed unidirectionally after the second-stage cylinder 2 extends outward, preventing internal leakage.

[0069] Optionally, the second contact 43 is an adjustable contact.

[0070] Optionally, an mounting plate is provided on the outer wall of the cylinder bottom 17 of the secondary cylinder 2, and the second contact member 43 is spirally mounted on the mounting plate. The contact head of the second contact member 43 is located on the side of the mounting plate near the valve core 32 of the second cone valve. At least one nut is provided on each side of the mounting plate, and the nut is threadedly connected to the second contact member 43.

[0071] In one example, two nuts are provided on each side of the mounting plate, and the two nuts have different thicknesses, with the thicker nut located on the side of the thinner nut closer to the mounting plate. This improves the stability of the second contact member 43 and prevents it from loosening during the operation of the secondary hydraulic cylinder 2.

[0072] It is understandable that by cooperating with the first and second limit switches, the multi-stage sequential telescopic cylinder is controlled by sequential logic, thereby realizing the sequential extension and retraction of the multi-stage sequential telescopic cylinder, improving the accuracy of sequential action and reducing the impact of leakage on the sequential action of the two-stage cylinder.

[0073] Understandably, both the first and second limit switches use conical seals for hydraulic locking to prevent the risk of increased leakage due to wear of the slide valve structure in the later stages. Furthermore, the use of long-stroke first spring 29 and second spring 33 in conjunction with the movement of the first cone valve core 30 and second cone valve core 32 compensates for the dimensional errors caused by the strokes of the first-stage cylinder 1 and the second-stage cylinder 2 on the first and second limit switches, thereby improving the accuracy of the sequential action of the multi-stage cylinders.

[0074] In one embodiment of this disclosure, see Figure 2 The second piston rod 6 also includes a second rod body 34 and a second piston 35. One end of the second rod body 34 extends out of the second cylinder 5 and connects to the second rod head 9. The other end of the second rod body 34 is fitted with the second piston 35. A buffer sleeve 36 is provided at the end of the second piston 35 away from the second rod body 34, and a second buffer sleeve 14 is fitted on the buffer sleeve 36. In this way, the second buffer sleeve 14 can be installed at the end of the second piston rod 6 near the rodless chamber, which can prevent the second piston rod 6 from directly impacting the cylinder bottom 17 and causing vibration and damage when moving in the second cylinder 5. At the same time, it avoids the defects of using a throttling method that require multiple tests and is greatly affected by oil temperature.

[0075] Optionally, the second buffer sleeve 14 is made of ORKOT-TLM material. The second buffer sleeve 14 has high strength and good elasticity and damping, which improves the buffering effect of the second buffer sleeve 14.

[0076] Understandably, the second buffer sleeve 14 is fitted onto the buffer lock sleeve 36. The contact area between the second buffer sleeve 14 and the cylinder bottom 17 is small, thus avoiding the problem of excessive starting pressure or inability to start the secondary oil cylinder 2.

[0077] Understandably, the thickness of the second buffer sleeve 14 can be designed according to the damping and elasticity requirements of the secondary hydraulic cylinder 2.

[0078] In one embodiment of this disclosure, see Figure 2The second rod body 34 is a hollow structure; the first oil pipe 11 is located inside the second rod body 34, with one end of the first oil pipe 11 extending into the second piston 35 and welded to the threaded connector 37. In this way, it is possible to easily plug the first oil pipe 11 after welding and pressurization process to avoid leakage of the first oil pipe 11.

[0079] In one embodiment of this disclosure, see Figure 2 and Figure 5 The slider 10 is mounted on the side wall of the first cylinder 3 near the second cylinder 5, and is connected to the first cylinder 3 by screws. The slider 10 is in close contact with the outer wall of the second cylinder 5. An oil cup 38 is provided on one side wall of the slider 10, and an oil delivery groove 39 is provided on the side wall of the slider 10 near the second cylinder 5. The oil cup 38 and the oil delivery groove 39 are connected by an oil delivery hole. In this way, the unstable phenomena such as low-speed creep of the slider 10 during the sequential extension and retraction of the first-stage cylinder 1 and the second-stage cylinder 2 can be eliminated, ensuring smooth relative operation of the first-stage cylinder 1 and the second-stage cylinder 2.

[0080] Optionally, the slider 10 is made of a self-lubricating material, and the surface of the second cylinder 5 is coated with wear-resistant paint. Lubricating oil is supplied between the slider 10 and the second cylinder 5 through the oil cup 38 and the oil delivery groove 39. In this way, the coefficient of friction between the slider 10 and the second cylinder 5 can be reduced, the relative stability of the movement of the slider 10 and the second cylinder 5 can be improved, and a suitable mechanical load-bearing capacity can be maintained.

[0081] In one embodiment of this disclosure, see Figure 7 The cylinder head 15 has a first step 40 and a second step 41 at one end near the cylinder tube 16. An O-ring 42 is provided between the first step 40 and the second step 41. The outer diameter of the first step 40 is larger than the outer diameter of the second step 41. This improves the process performance of the cylinder head 15.

[0082] Optionally, a sealant is provided between the end of the cylinder flange 18 furthest from the cylinder tube 16 and the cylinder head 15. This prevents the cylinder head 15 from failing due to the failure or omission of the static seal O-ring, which could cause oil pressure to be transmitted to the threads, resulting in the external expansion of the threads of the cylinder flange 18 and a reduction in the meshing force with the threads of the cylinder head 15. This also prevents external water from entering the cylinder and prevents high pressure buildup inside the cylinder.

[0083] In one embodiment of this disclosure, see Figures 1 to 7 The working process of this bundled multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics is briefly described as follows:

[0084] In use, oil is first introduced into the core tube 24 through the first rod head 21. The oil pressure enters the rodless chamber of the first-stage cylinder 1 through the core cylinder 25. The oil pressure pushes the core cylinder 25 and the first cylinder 3 to extend outward. The first cylinder 3 drives the second-stage cylinder 2 to extend outward together through the support plate 7 and the pin 8. When the first contacting member 26 contacts the first piston 22, the stroke of the first-stage cylinder 1 ends. The oil pressure pushes the locking sleeve 27 and the first cone valve core 30 to move in opposite directions, causing the first spring 29 to compress. As the opening of the first cone valve core 30 increases, pressurized oil flows into the rodless chamber of the second-stage cylinder 2 through the second oil pipe 12, causing the second cylinder 5 to slide within the slider 10 and extend, thus achieving the sequential extension of the first-stage cylinder 1 and the second-stage cylinder 2. The first rod head 21 switches the oil pressure direction, and oil pressure enters the rod chamber of the first-stage cylinder 1. The rod chambers of the first-stage cylinder 1 and the second-stage cylinder 2 are connected through the first oil pipe 11, and oil pressure enters the second-stage cylinder 2 through the first oil pipe 11. In the rod chamber of the first-stage cylinder 2, the oil circuit of the first-stage cylinder 1 is cut off, and the first-stage cylinder 1 cannot move. The oil pressure of the second-stage cylinder 2 pushes the second cylinder 5 to slide within the slider 10, causing the second cylinder 5 to retract. The oil in the rodless chamber of the second-stage cylinder 2 flows back through the second oil pipe 12 and the core tube 24. When the stroke of the second-stage cylinder 2 ends, the second buffer sleeve 14 makes buffer contact with the second piston 35; the second contact element 43 collides with the second cone valve core 32, and the second contact element 43 presses the second cone valve core 32, driving the second spring 33 to compress, causing the oil in the rodless chamber of the first-stage cylinder 1 to flow back through the core tube 25 and the core tube 24, causing the first cylinder 3 to retract. When the stroke of the first-stage cylinder 1 ends, the first buffer sleeve 13 makes buffer contact with the first piston 22, realizing the sequential retraction of the first-stage cylinder 1 and the second-stage cylinder 2, thereby realizing the sequential extension and retraction of the first-stage cylinder 1 and the second-stage cylinder 2, improving the smoothness and reliability of the sequential action of the first-stage cylinder 1 and the second-stage cylinder 2.

[0085] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the utility models disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics, characterized in that, It includes at least one primary cylinder (1) and one secondary cylinder (2), wherein the primary cylinder (1) includes a first cylinder barrel (3) and a first piston rod (4), and the secondary cylinder (2) includes a second cylinder barrel (5) and a second piston rod (6); One end of the first cylinder (3) is connected to the second rod head (9) of the second piston rod (6) through a support plate (7) and a pin (8), and the other end of the first cylinder (3) is slidably connected to the second cylinder (5) through a slider (10); The rod chamber of the first-stage cylinder (1) and the rod chamber of the second-stage cylinder (2) are connected by a first oil pipe (11), and the rodless chamber of the first-stage cylinder (1) and the rodless chamber of the second-stage cylinder (2) are connected by a second oil pipe (12). The first piston rod (4) is provided with a first buffer sleeve (13) at one end near the rodless cavity, and the second piston rod (6) is provided with a second buffer sleeve (14) at one end near the rodless cavity.

2. The multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics according to claim 1, characterized in that, The first cylinder (3) and the second cylinder (5) respectively include a cylinder head (15), a cylinder tube (16) and a cylinder bottom (17) arranged sequentially; A cylinder flange (18) is fitted on the cylinder head (15), and a U-shaped cut (19) is provided between the cylinder flange (18) and the cylinder tube (16). The cylinder flange (18) and the cylinder tube (16) are connected by welding in the U-shaped cut (19). The width of the cylinder flange (18) of the first-stage cylinder (1) is greater than the width of the support plate (7).

3. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 2, characterized in that, The first piston rod (4) includes a first rod body (20), a first rod head (21), and a first piston (22); One end of the first rod (20) extends out of the first cylinder (3) and connects to the first rod head (21). The other end of the first rod (20) is fitted with the first piston (22). The end of the first piston (22) away from the first rod (20) is provided with a support sleeve (23). The first buffer sleeve (13) is fitted on the support sleeve (23).

4. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 3, characterized in that, The first rod (20) is a hollow structure; The first rod body (20) is provided with a core tube (24), the core tube (24) is provided with a core cylinder (25), one end of the core cylinder (25) is provided with a first contact element (26), the other end of the core cylinder (25) extends out of the core cylinder (25) and passes through the first piston (22) and the support sleeve (23) in sequence; The cylinder bottom (17) is provided with a first cavity that communicates with the rodless chamber of the first-stage oil cylinder (1). The first cavity is connected to the second oil pipe (12). The first cavity is provided with a support sleeve (28), a first spring (29) and a first cone valve core (30) in sequence. The other end of the core cylinder (25) passes through the support sleeve (28), the first spring (29) and the first cone valve core (30) in sequence and is connected to the locking sleeve (27). The support sleeve (28) is fixedly connected to the cylinder bottom (17), and the first cone valve core (30) abuts against the locking sleeve (27).

5. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 4, characterized in that, A second cavity is provided below the first cavity, and the second cavity is connected to the first cavity and the rodless cavity of the first-stage hydraulic cylinder (1); A mounting sleeve (31) is provided at one end of the second cavity, and a second cone valve core (32) is provided at the other end of the second cavity. A second spring (33) is provided inside the mounting sleeve (31). One end of the second spring (33) extends out of the mounting sleeve (31) and connects with the second cone valve core (32). The second cone valve core (32) can reciprocate within the second cavity. One end of the second cone valve core (32) extends out of the cylinder bottom (17) and contacts the second contact member (43), which is disposed on the cylinder bottom (17) of the second cylinder (5).

6. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 1, characterized in that, The second piston rod (6) also includes a second rod body (34) and a second piston (35); One end of the second rod (34) extends out to the second cylinder (5) and connects to the second rod head (9). The other end of the second rod (34) is fitted with the second piston (35). The end of the second piston (35) away from the second rod (34) is provided with a buffer lock sleeve (36). The second buffer sleeve (14) is fitted on the buffer lock sleeve (36).

7. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 6, characterized in that, The second rod (34) is a hollow structure; The first oil pipe (11) is disposed inside the second rod body (34), and one end of the first oil pipe (11) extends into the second piston (35) and is welded to the threaded connector (37).

8. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 1, characterized in that, The slider (10) is disposed on the side wall of the first cylinder (3) near the second cylinder (5), and the slider (10) is connected to the first cylinder (3) by screws. The slider (10) is in contact with the outer wall of the second cylinder (5). An oil filling cup (38) is provided on one side wall of the slider (10), and an oil delivery groove (39) is provided on one side wall of the slider (10) near the second cylinder (5). The oil filling cup (38) and the oil delivery groove (39) are connected through an oil delivery hole.

9. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 2, characterized in that, The cylinder head (15) is provided with a first step (40) and a second step (41) at one end near the cylinder tube (16). An O-ring (42) is provided between the first step (40) and the second step (41). The outer diameter of the first step (40) is larger than the outer diameter of the second step (41). A sealant is provided between the end of the cylinder flange (18) away from the cylinder tube (16) and the cylinder head (15).

10. A multi-stage sequential telescopic hydraulic cylinder with buffer damping characteristics as described in claim 1, characterized in that, The slider (10) is made of a self-lubricating material; Both the first buffer sleeve (13) and the second buffer sleeve (14) are made of ORKOT-TLM material.

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