A multi-stage buffer with a locking structure

Abstract

The present invention discloses a multi-stage buffer with a locking structure, comprising a first-stage piston rod slidably nested in an outer cylinder barrel, a second-stage piston rod slidably nested in the first-stage piston rod, and a floating piston is provided at the outer end of the second-stage piston rod; a guide piston sleeve and a damping ring are fixedly connected to the inner wall of the inner end of the second-stage piston rod; a buffer rod is fixedly connected to the inner wall of the inner end of the first-stage piston rod, and the buffer rod comprises an outer end of an intermediate shaft which is sequentially provided with a step shaft and a buffer rod piston; a circulation hole is provided on the circumferential side wall of the intermediate shaft, a second connecting hole connected with the circulation hole is provided on the end surface of the outer end of the buffer rod piston, a buffer groove which is interconnected with the circulation hole is provided on the circumferential outer wall of the inner end of the step shaft, and a cross-sectional area change curve of the buffer groove decreases in a nearly parabolic manner toward the direction of the buffer rod piston; the present invention has the advantages of small extension resistance, fast extension speed, both speed and stability in the damping and buffering deceleration stage, compact structure, short buffer stroke, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of buffers, and specifically to a multi-stage buffer with a locking structure. Background Art

[0002] An oil-gas buffer mainly consists of an outer cylinder and a piston rod. The outer cylinder and the piston rod form an oil chamber and a gas chamber. The oil chamber is filled with damping oil, and the gas chamber is filled with dry air or inert gas. When the buffer works, an external force "pushes" the oil in the oil chamber into the gas chamber through the piston rod. At this time, under the action of the external force, the oil flows through small holes to generate damping and dissipate the impact energy of the buffer. In this damping process, mechanical energy is converted into heat energy. Generally speaking, the buffer can be set for contraction buffering and stretching buffering, and contraction buffers are more common in the market; currently, most of the multi-stage buffers installed on many mechanical devices control the buffer system of the device by using a constant damping force or a multi-stage fixed damping force. The damping force exists throughout the buffering process. The problems of this structure are large volume, heavy weight, large buffering stroke, and difficult to accurately control the damping force. In some specific usage environments, it is required that the buffer can quickly extend in the initial elongation stage, complete the mechanism action after extending to the middle section of the stroke, and then enter the final stage of damping buffering and deceleration. The damping buffering and deceleration stage requires a large and stable damping force to achieve fast and stable deceleration buffering. Patent Publication No. CN109319099B discloses an elongation stroke variable oil hole landing gear buffer, which realizes fast elongation in the initial elongation stage and rapid speed reduction and has a large damping buffering force in the damping buffering and deceleration stage at the end of elongation through the variable oil hole of the multi-stage buffer. However, there is still a large damping force in the fast elongation stage, the fast elongation effect is poor, the deceleration in the damping buffering and deceleration stage at the end of elongation is not stable, the damping buffering force is not stable, it cannot balance speed and stability, damping impact and self-vibration are likely to occur during the process, and there is no mechanical locking mechanism after moving in place, so that the final state will change with the gravity environment of the carrier mechanism, resulting in unstable use performance and other problems. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the existing defects and provide a multi-stage buffer with a locking structure, which has a small sudden extension resistance and a fast extension speed in the fast elongation stage, balances speed and stability in the damping buffering and deceleration stage at the end of elongation, and mechanical locking mechanisms are provided on both the first-stage piston rod and the second-stage piston rod after moving in place. It has smooth telescoping, small volume, light weight, compact structure, short buffering stroke, stable buffering resistance, convenient operation, and small occupied space, and can effectively solve the problems in the background art.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a multi-stage buffer with a locking structure, comprising a first-stage piston rod slidably nested in an outer cylinder barrel, a second-stage piston rod slidably nested in the first-stage piston rod, both the first-stage piston rod and the second-stage piston rod are hollow tube structures, an earring is fixedly connected to the outer port of the second-stage piston rod, and a floating piston is provided in the second-stage piston rod; a guide piston sleeve is fixedly connected to the inner wall of the inner end of the second-stage piston rod, and a damping ring is provided on the inner wall of the second-stage piston rod near the guide piston sleeve; a buffer rod coaxially arranged therewith is fixedly connected to the inner wall of the inner end of the first-stage piston rod, the buffer rod comprises an intermediate shaft, a step shaft is provided at the outer end of the intermediate shaft, the outer diameter of the step shaft is larger than the outer diameter of the intermediate shaft and smaller than the inner diameter of the damping ring, and the outer end of the step shaft is There is a buffer rod piston that is compatible with the inner diameter of the secondary piston rod, and the buffer rod piston fits with the floating piston; a circulation hole is opened on the circumferential side wall of the outer end of the intermediate shaft, and a second connecting hole connected to the circulation hole is opened on the end face of the outer end of the buffer rod piston, and a buffer groove that is interconnected with the circulation hole is opened on the circumferential outer wall of the inner end of the step shaft, and the cross-sectional area of ​​the buffer groove decreases toward the buffer rod piston, and the change curve of the cross-sectional area of ​​the buffer groove is approximately a parabola; the guide piston sleeve is slidably nested on the intermediate shaft, and the damping ring is located on the inner side of the circulation hole; a buffer oil chamber is formed between the inner wall of the secondary piston rod, the outer wall of the buffer rod and the guide piston sleeve, and a buffer air chamber is formed between the inner wall of the secondary piston rod, the earring and the floating piston, and the buffer oil chamber and the buffer air chamber are filled with shock-absorbing oil and gas respectively.

[0005] Furthermore, a plurality of accommodating holes are provided on the circumferential side wall of the inner end of the first-stage piston rod, and a first-stage locking steel ball is provided in the steel ball accommodating hole. A locking sleeve structure is provided in the first-stage piston rod for squeezing the first-stage locking steel ball outward and making it escape from the accommodating hole. A first-stage steel ball locking groove is provided on the inner wall of the outer end of the outer cylinder at the position corresponding to the first-stage locking steel ball.

[0006] Furthermore, the locking sleeve structure 1 includes a spring seat 1 and a primary locking sleeve, the spring seat 1 is threadedly connected to the port at the inner end of the primary piston rod, the primary locking sleeve is slidably nested in the primary piston rod at the position of the accommodating hole 1, and a concave surface 1 for supporting the bottom end of the primary locking steel ball is provided on the circumferential outer wall of the outer end of the primary locking sleeve, and when the primary locking sleeve moves toward the outer end, the concave surface 1 causes the primary locking steel ball to push outward along the radial direction of the outer cylinder.

[0007] Furthermore, the inner end of the buffer rod is threadedly connected to a positioning flange, and the positioning flange is threadedly connected to the inner wall of the primary piston rod; a positioning hole is opened on one end face of the positioning flange, and a push rod is slidably nested in the positioning hole, and both ends of the push rod are respectively fitted with the outer end of the primary locking sleeve and the inner end face of the guide piston sleeve.

[0008] Furthermore, a micro switch 1 is fixedly provided on the circumferential outer wall of the outer cylinder at a position corresponding to the primary steel ball locking groove, and the detection end of the micro switch 1 penetrates into the primary steel ball locking groove.

[0009] Furthermore, a second accommodating hole is provided on the circumferential side wall of the outer end of the first-level piston rod, and a secondary locking steel ball is provided in the steel ball accommodating hole ear, and the outer wall of the secondary piston rod is in contact with the inner wall of the outer end of the first-level piston rod; a second locking sleeve structure is provided on the circumferential outer wall of the outer end of the first-level piston rod for squeezing the secondary locking steel ball inward and making it escape from the second accommodating hole, and a secondary steel ball locking groove is provided on the inner wall of the outer end of the secondary piston rod at a position corresponding to the inner side of the secondary locking steel ball.

[0010] Furthermore, the locking sleeve structure 2 includes a secondary locking sleeve which is provided on the circumferential side wall of the outer end of the primary piston rod and can slide along its axial direction. The secondary locking sleeve is connected to the primary piston rod through a spring 3, and the elastic force generated by the spring 3 on the secondary locking sleeve causes it to move toward the outer end of the primary piston rod; a concave surface 2 for supporting the top end of the secondary locking steel ball is provided on the circumferential inner wall of the outer end of the secondary locking sleeve, and when the secondary locking sleeve moves toward the outer end, the concave surface 2 causes the secondary locking steel ball to be pushed inward along the radial direction of the secondary piston rod.

[0011] Furthermore, a micro switch 2 is fixedly provided on the circumferential side wall of the secondary piston rod at the outer end corresponding to the secondary locking sleeve, the detection end of the micro switch 2 faces the secondary locking sleeve, and when the secondary locking steel ball is nested in the secondary steel ball locking groove, the secondary locking sleeve will move toward the micro switch 2.

[0012] Furthermore, the buffer groove is a rectangular groove, and the bottom surface of the buffer groove is an upwardly curved and concave arc surface structure.

[0013] Furthermore, a first connecting hole is provided on the circumferential side wall of the stepped shaft, a detection cavity connected to the first connecting hole is provided on the inner end surface of the intermediate shaft along its axial direction, and a temperature and pressure sensor is sealed and fixed in the detection cavity.

[0014] Furthermore, an oil storage groove is provided on the outer end surface of the buffer rod piston, and the second communicating holes are all located in the oil storage groove.

[0015] Furthermore, a convex shaft is provided at the inner end of the intermediate shaft, and a locking nut is threadedly connected to the convex shaft, and the outer end of the locking nut is fitted with the inner end surface of the positioning flange.

[0016] Furthermore, the inner end of the earring is fixedly connected with a spring seat 2 which fits the inner wall of the secondary piston rod, and a spring 2 is arranged between the spring seat 2 and the floating piston. The earring is provided with a waterproof breathable valve which is connected with the buffer air cavity.

[0017] Further, a guiding key is fixedly arranged on the inner wall of the outer cylinder at its outer side end, and a guiding groove is axially formed on the outer wall of the first-stage piston rod at a position corresponding to the guiding key.

[0018] Further, the damping ring and the second-stage piston rod are of an integral structure.

[0019] Further, the damping ring and the second-stage piston rod are of a split structure, and receiving grooves are formed at both axial ends of the second-stage piston rod corresponding to the damping ring, and elastic retaining rings for restricting the axial movement of the damping ring are fixedly nested in the receiving grooves.

[0020] Further, the outer cylinder is of a hollow tube structure, and an end cover is threadedly connected to the inner side end port of the outer cylinder, and a sealing ring is nested on the circumferential side wall of the end cover.

[0021] Further, a first guiding band is arranged on the circumferential outer wall of the first-stage piston rod, and the first-stage piston rod is slidably connected to the inner wall of the outer cylinder through the first guiding band; a second guiding band is arranged on the circumferential outer wall of the second-stage piston rod, and the second-stage piston rod is slidably connected to the inner wall of the first-stage piston rod through the second guiding band.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: for the multi-stage buffer with a locking structure, when the buffer initially extends, first, the first-stage piston rod quickly extends outward relative to the outer cylinder, and during the rapid extension process of the first-stage piston rod, there is only slight frictional force and damping force, meeting the requirement of sudden extension of the buffer, and the sudden extension speed is fast and the resistance is small; when the first-stage piston rod extends in place and is locked, the damping force received by the second-stage piston rod will instantaneously increase, thereby reducing the extension speed of the second-stage piston rod. When the first-stage piston rod continues to extend, by changing the damping cross-sectional area of the buffer, the change curve of the damping cross-sectional area approximately decreases in a parabola, so that the damping force received by the second-stage piston rod is a constant value, and thus the deceleration acceleration of the second-stage piston rod is a constant value. When the second-stage piston rod extends in place and is locked with the first-stage piston rod, the multi-stage buffer has a small sudden extension resistance and a fast extension speed during the rapid extension stage, takes into account speed and stability during the damping buffer deceleration stage, and both the first-stage piston rod and the second-stage piston rod are provided with mechanical locking mechanisms after moving in place, with stable telescoping, small volume, light weight, compact structure, short buffer stroke, stable buffer resistance, convenient operation, and small occupied space. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the present invention;

[0024] Figure 2 is a schematic internal structure diagram of the second-stage piston rod of the present invention;

[0025] Figure 3 is a schematic internal structure diagram of the inner side end of the outer cylinder of the present invention;

[0026] Figure 4 Schematic diagram of the internal structure at the outer end of the outer cylinder of the present invention;

[0027] Figure 5 Schematic diagram of the buffer rod structure of the present invention;

[0028] Figure 6 Front view of the buffer rod of the present invention;

[0029] Figure 7 Cross-sectional view of the buffer rod of the present invention along the axial direction of the flow hole;

[0030] Figure 8 Cross-sectional view of the buffer rod of the present invention along the axial direction of the first communication hole;

[0031] Figure 9 Schematic diagram of the structure when the damping ring of the second-stage piston rod of the present invention first reaches the stepped shaft;

[0032] Figure 10 Schematic diagram of the structure when the damping ring of the second-stage piston rod of the present invention is in full contact with the stepped shaft;

[0033] Figure 11 Schematic diagram of the structure when the damping ring of the second-stage piston rod of the present invention slides relative to the stepped shaft;

[0034] Figure 12 Schematic diagram of the structure when the damping ring of the second-stage piston rod of the present invention reaches the end position during movement on the stepped shaft;

[0035] Figure 13 Schematic diagram of the integral structure of the second-stage piston rod and the damping ring of the present invention;

[0036] Figure 14 Schematic diagram of the split structure of the second-stage piston rod and the damping ring of the present invention;

[0037] Figure 15 Schematic diagram of the change in the damping cross-sectional area during the stage from when the damping ring first reaches the stepped shaft to when it reaches the end position of the present invention;

[0038] Figure 16 Schematic diagram of the change in the buffer force of the damper during the stage from when the damping ring first reaches the stepped shaft to when it reaches the end position of the present invention.

[0039] In the figure: 1 outer cylinder barrel, 101 first-stage steel ball locking groove, 102 guide groove, 2 first-stage piston rod, 201 first guide band, 3 second-stage piston rod, 301 second guide band, 302 guide piston sleeve, 303 damping ring, 304 second-stage steel ball locking groove, 305 circlip, 4 buffer rod, 41 intermediate shaft, 411 flow hole, 412 detection cavity, 42 stepped shaft, 421 buffer groove, 422 first communication hole, 43 buffer rod piston, 431 second communication hole, 432 oil storage groove, 44 chamfer, 45 convex shaft, 5 end cover, 6 first spring seat, 7 first-stage locking sleeve, 8 first spring, 9 positioning flange, 91 ejector rod, 10 first-stage locking steel ball, 11 earring, 111 waterproof and breathable valve, 12 second spring seat, 13 floating piston, 14 second spring, 15 buffer air cavity, 16 buffer oil cavity, 17 second-stage locking sleeve, 18 third spring, 19 second-stage locking steel ball, 20 microswitch two, 21 microswitch one, 22 temperature and pressure sensor, 23 locking nut, 24 guide key, 25 extrusion oil cavity. Detailed implementation manners

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0041] Please refer to Figure 1-16, the present invention provides a technical solution: a multi-stage buffer with a locking structure, which includes a first-stage piston rod 2 slidably nested in an outer cylinder 1, and a second-stage piston rod 3 slidably nested in the first-stage piston rod 2. Both the first-stage piston rod 2 and the second-stage piston rod 3 are hollow tube structures. An earring 11 is fixedly connected to the outer side port of the second-stage piston rod 3, and a waterproof and breathable valve 111 communicating with a buffer air chamber 15 is provided on the earring 11, and a floating piston 13 is provided in the second-stage piston rod 3. A guide piston sleeve 302 is fixedly connected to the inner wall of the inner side end of the second-stage piston rod 3, and a damping ring 303 is provided on the inner wall of the second-stage piston rod 3 near the guide piston sleeve 302. A buffer rod 4 coaxially arranged with it is fixedly connected to the inner wall of the inner side end of the first-stage piston rod 2. The buffer rod 4 includes a middle shaft 41, a stepped shaft 42 is provided at the outer side end of the middle shaft 41. The outer diameter of the stepped shaft 42 is larger than the outer diameter of the middle shaft 41 and smaller than the inner diameter of the damping ring 303. A buffer rod piston 43 adapted to the inner diameter of the second-stage piston rod 3 is provided at the outer side end of the stepped shaft 42, and the buffer rod piston 43 is in contact with the floating piston 13. A flow hole 411 is formed on the circumferential side wall of the outer side end of the middle shaft 41, and a second communication hole 431 communicating with the flow hole 411 is formed on the end surface of the outer side end of the buffer rod piston 43. A buffer groove 421 communicating with the flow hole 411 is formed on the circumferential outer wall of the inner side end of the stepped shaft 42. The buffer groove 421 is a rectangular groove, and the bottom surface of the buffer groove 421 is an upwardly curved and concave arc surface structure. The cross-sectional area change curve of the buffer groove 421 in the direction towards the buffer rod piston 43 approximately decreases in a parabola. The guide piston sleeve 302 is slidably nested on the middle shaft 41, and the damping ring 303 is located inside the flow hole 411. A buffer oil chamber 16 is formed between the inner wall of the second-stage piston rod 3, the outer wall of the buffer rod 4 and the guide piston sleeve 302. A buffer air chamber 15 is formed between the inner wall of the second-stage piston rod 3, the earring 11 and the floating piston 13. Shock-absorbing oil and gas are respectively filled in the buffer oil chamber 16 and the buffer air chamber 15.

[0042] A plurality of accommodating holes are provided on the circumferential side wall of the inner end of the primary piston rod 2, and a primary locking steel ball 10 is provided in the steel ball accommodating hole. A locking sleeve structure is provided in the primary piston rod 2 for squeezing the primary locking steel ball 10 outward and causing it to escape from the accommodating hole. The locking sleeve structure comprises a spring seat 6 and a primary locking sleeve 7. The spring seat 6 is threadedly connected to the port at the inner end of the primary piston rod 2. The primary locking sleeve 7 is slidably nested in the primary piston rod 2 at the position of the accommodating hole. A concave surface is provided on the circumferential outer wall at the outer end of the primary locking sleeve 7 for supporting the bottom end of the primary locking steel ball 10. When the primary locking sleeve 7 moves toward the outer end, the concave surface causes the primary locking steel ball 10 to move along the outer cylinder barrel. 1 is pushed up toward the outside in the radial direction; the inner end of the buffer rod 4 is threadedly connected with a positioning flange 9, and the positioning flange 9 is threadedly connected to the inner wall of the primary piston rod 2; a positioning hole is provided on one end face of the positioning flange 9, and a push rod 91 is slidably nested in the positioning hole, and the two ends of the push rod 91 are respectively fitted with the outer end of the primary lock sleeve 7 and the inner end face of the guide piston sleeve 302; a primary steel ball locking groove 101 is provided on the inner wall of the outer end of the outer cylinder 1 at the position corresponding to the primary locking steel ball 10; a micro switch 21 is fixedly provided on the circumferential outer wall of the outer cylinder 1 at the position corresponding to the primary steel ball locking groove 101, and the detection end of the micro switch 21 passes through the primary steel ball lock The first piston rod 2 is provided with a second accommodating hole on the circumferential side wall of the outer end of the first piston rod 2, and a second locking steel ball 19 is provided in the steel ball accommodating hole ear, and the outer wall of the second piston rod 3 is in contact with the inner wall of the outer end of the first piston rod 2; the outer circumferential outer wall of the outer end of the first piston rod 2 is provided with a second locking sleeve structure for squeezing the second locking steel ball 19 inward and making it escape from the second accommodating hole, and the inner wall of the outer end of the second piston rod 3 is provided with a second steel ball locking groove 304 at a position corresponding to the inner side of the second locking steel ball 19; the second locking sleeve structure includes a second locking sleeve 17 which is provided on the circumferential side wall of the outer end of the first piston rod 2 and can slide along its axial direction, and the second locking sleeve 17 is locked by a spring 3 1 8 is connected to the primary piston rod 2, and the elastic force generated by the spring three 18 on the secondary locking sleeve 17 makes it move toward the outer end of the primary piston rod 2; a concave surface two is provided on the circumferential inner wall of the outer end of the secondary locking sleeve 17 for supporting the top end of the secondary locking steel ball 19, and when the secondary locking sleeve 17 moves toward the outer end, the concave surface two makes the secondary locking steel ball 19 push out inward along the radial direction of the secondary piston rod 3; a micro switch two 20 is fixedly provided on the circumferential side wall of the secondary piston rod 3 at the outer end corresponding to the secondary locking sleeve 17, the detection end of the micro switch two 20 faces the secondary locking sleeve 17, and when the secondary locking steel ball 19 is nested in the secondary steel ball locking groove 304, the secondary locking sleeve 17 will move toward the micro switch two 20.

[0043] A first communication hole 422 is formed in the circumferential side wall of the stepped shaft 42, and a detection cavity 412 communicating with the first communication hole 422 is formed in the inner end face of the intermediate shaft 41 along its axial direction. A temperature and pressure sensor 22 is fixedly arranged in the detection cavity 412 in a sealed manner.

[0044] Working principle:

[0045] By fixedly connecting the earring 11 at the outer end of the secondary piston rod 3 to an external device, when the secondary piston rod 3 is initially extended, the secondary piston rod 3 is extended outward relative to the outer cylinder 1 due to the gravity of the external device. The guide piston sleeve 302 and the damping ring 303 on the secondary piston rod 3 slide along the intermediate shaft 41 on the buffer rod 4. The guide piston sleeve 302 and the damping ring 303 will squeeze the oil in the buffer oil cavity 16. The oil in the buffer oil cavity 16 flows through the circulation hole 411 and the second communication hole 431 in sequence and then flows to between the buffer rod piston 43 and the floating piston 13, and causes the floating piston 13 to squeeze the gas in the buffer gas cavity 15, so that the gas in the buffer gas cavity 15 is discharged to the external environment through the waterproof and breathable valve 111 on the earring 11. The damping force generated by the damping oil on the damping ring 303 and the guide piston sleeve 302 is used to buffer the secondary piston rod 3 and the external device. Since the buffer rod 4 is fixedly arranged on the primary piston rod 2, and the primary piston rod 2 and the outer cylinder 1 are in a sliding fit connection, and the frictional force is much smaller than the damping force. Therefore, when the secondary piston rod 3 is initially extended, the primary piston rod 2 will quickly extend outward following the secondary piston rod 3 to meet the requirement of the sudden extension of the buffer;

[0046] When the primary locking steel ball 10 on the primary piston rod 2 moves to the primary steel ball locking groove 101 provided on the outer cylinder 1, the concave surface 1 of the primary locking sleeve 7 is pushed by the elastic force applied by the first spring 8 to push the primary locking steel ball 10 into the primary locking groove 101, and the primary piston rod 2 and the outer cylinder 1 are interlocked; after detecting the primary locking steel ball 10 through the first micro switch 21, it is determined that the primary piston rod 2 has moved in place; after the primary piston rod 2 and the outer cylinder 1 are interlocked, the secondary piston rod 3 continues to extend outward relative to the primary piston rod 2;

[0047] When the damping ring 303 on the secondary piston rod 3 moves to the stepped shaft 42, the clearance between the damping ring 303 and the stepped shaft 42 is a clearance fit of 0.01 mm to 0.05 mm. The clearance between the inner wall of the damping ring 303 and the buffer rod 4 becomes smaller, and the damping cross-sectional area between the damping ring 303 and the buffer rod 4 decreases. When the secondary piston rod 3 slides along the buffer rod 4, the damping force will increase instantaneously. The secondary piston rod 3 is subjected to the damping force and its telescopic speed slows down. The damping oil between the damping ring 303 and the buffer rod piston 43 flows into the flow-through hole 411 through the clearance between the damping ring 303 and the stepped shaft 42 and the buffer groove 421. As the secondary piston rod 3 continues to extend outwards, the damping cross-sectional area change curve between the damping ring 303 and the buffer groove 421 decreases approximately parabolically, so that the damping force received by the secondary piston rod 3 is a constant value, and the deceleration acceleration of the secondary piston rod 3 is a constant value;

[0048] When the damping ring 303 moves to the end of the buffer groove 421, the secondary steel ball locking groove 304 on the secondary piston rod 3 moves to the position of the secondary locking steel ball 19. The secondary locking sleeve 17 is subjected to the elastic force of the spring three 18, and its concave surface two presses the secondary locking steel ball 19 into the secondary steel ball locking groove 304, so that the secondary piston rod 3 and the primary piston rod 2 are interlocked. The secondary locking sleeve 17 is subjected to the elastic force of the spring three 18 and slides outwards along the primary piston rod 2. Finally, the secondary locking sleeve 17 triggers the microswitch two 20, and the secondary locking sleeve 17 is detected through the microswitch two 20, thereby determining that the secondary piston rod 3 has moved in place;

[0049] The damping oil in the buffer oil chamber 16 flows into the extrusion oil chamber 25 between the buffer rod piston 43 and the floating piston 13. During the process of the secondary piston rod 2 extending outwards, the damping oil in the extrusion oil chamber 25 continuously increases, so that the floating piston 13 continuously compresses the gas in the buffer air chamber 15, and the gas in the buffer air chamber 15 is discharged to the external environment through the waterproof and breathable valve 111 on the earring 11;

[0050] When the multi-stage buffer is in use, the damping oil in the buffer oil chamber 16 flows into the detection chamber 412 through the first communication hole 422, and the temperature and pressure of the damping oil in the buffer oil chamber 16 are detected in real time through the temperature and pressure sensor 22;

[0051] The unlocking method of the multi-stage buffer is to push the secondary lock sleeve 17 inwardly, and push the secondary piston rod 3 inwardly, so that the secondary locking steel ball 19 is disengaged from the secondary steel ball locking groove 304, thereby unlocking the secondary piston rod 3, and the secondary locking steel ball 19 is restored to a state of contact with the concave surface 2 of the secondary lock sleeve 17; the air pressure in the buffer air chamber 15 causes the floating piston 13 to squeeze the shock-absorbing oil in the squeeze oil chamber 25 to flow into the buffer oil chamber 16, so that the secondary piston rod 3 slides inwardly of the primary piston rod 2; when the secondary piston rod 3 moves inwardly to the original position, the guide piston sleeve 302 squeezes the push rod 91 inwardly, and the push rod 91 squeezes the primary lock sleeve 7 to overcome the elastic force of the spring 8 and move inwardly, so that the primary locking steel ball 10 is disengaged from the primary steel ball locking groove 101, thereby unlocking the primary piston rod 2, and the primary locking steel ball 10 is restored to a state of contact with the concave surface 1 of the primary lock sleeve 7;

[0052] The multi-stage buffer disclosed in this embodiment has the following structure: when the buffer is initially extended, the first-stage piston rod 2 and the second-stage piston rod 3 are firstly extended outward rapidly relative to the outer cylinder 1, and there is only a slight friction force in the process of rapid extension of the first-stage piston rod 2, which meets the requirement of the buffer to extend, and the extension speed is fast and the resistance is small; when the first-stage piston rod 2 is extended and locked in place, the damping force on the second-stage piston rod 3 will increase instantly, reducing the extension speed of the second-stage piston rod 3. After the first-stage piston rod 2 continues to extend, the damping cross-sectional area of ​​the buffer is changed, and the damping cross-sectional area change curve decreases approximately in a parabolic manner, so that the damping force on the second-stage piston rod 3 is constant, thereby making the second-stage piston rod 3 The deceleration acceleration of the piston rod 3 is a constant value. When the secondary piston rod 3 is extended into place, it is locked with the primary piston rod 2. The multi-stage buffer has a small extension resistance and a fast extension speed in the rapid extension stage. Both speed and stability are taken into account in the damping and buffering deceleration stage. Both the primary piston rod 2 and the secondary piston rod 3 are provided with a mechanical locking mechanism after moving into place. The mechanism has stable operation, small size, light weight, compact structure, short buffering stroke, relatively stable buffering resistance, and reduces the body vibration caused by damping impact. The operation is convenient and the space occupied is small. The mechanical locking mechanism provided after moving into place ensures that the final state will not change with the gravity environment of the carrier mechanism, and the use state is stable.

[0053] Furthermore, an oil storage groove 432 is formed on the outer end surface of the buffer rod piston 43 , and the second communication holes 431 are all located in the oil storage groove 432 .

[0054] Furthermore, a convex shaft 45 is provided at the inner end of the intermediate shaft 41 , and a locking nut 23 is threadedly connected to the convex shaft 45 , and the outer end of the locking nut 23 is in contact with the inner end surface of the positioning flange 9 .

[0055] Further, a second spring seat 12 that fits against the inner wall of the secondary piston rod 3 is fixedly connected to the inner end of the earring 11, and a second spring 14 is provided between the second spring seat 12 and the floating piston 13. After the multi-stage buffer is unlocked, the floating piston 13 is quickly restored to its original position by the second spring 14.

[0056] Further, a guide key 24 is fixedly provided on the inner wall of the outer cylinder 1 at the outer end, and a guide groove 102 is axially formed in the outer wall of the primary piston rod 2 at the position corresponding to the guide key 24. The guide key 24 guides the telescopic movement of the primary piston rod 2 to prevent it from rotating during the telescopic process.

[0057] Further, the damping ring 303 and the secondary piston rod 3 are of an integral structure, which is convenient for the assembly of the secondary piston rod 3.

[0058] Further, the damping ring 303 and the secondary piston rod 3 are of a split structure, and receiving grooves are formed at both axial ends of the secondary piston rod 3 corresponding to the damping ring 303. Elastic retaining rings 305 that restrict the axial movement of the damping ring 303 are fixedly nested in the receiving grooves, which is convenient for the processing of the damping ring 303 and the secondary piston rod 3 and is also convenient for assembly.

[0059] Further, the outer cylinder 1 is of a hollow tube structure, and an end cover 5 is threadedly connected to the inner end port of the outer cylinder 1, and a sealing ring is nested on the circumferential side wall of the end cover 5.

[0060] Further, a first guide band 201 is provided on the circumferential outer wall of the primary piston rod 2, and the primary piston rod 2 is slidably connected to the inner wall of the outer cylinder 1 through the first guide band 201; a second guide band 301 is provided on the circumferential outer wall of the secondary piston rod 3, and the secondary piston rod 3 is slidably connected to the inner wall of the primary piston rod 2 through the second guide band 301. The first guide band 201 and the second guide band 301 respectively reduce the sliding friction of the primary piston rod 2 and the secondary piston rod 3.

[0061] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made therein without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A multi-stage buffer with a locking structure, comprising a first-stage piston rod (2) slidably nested within an outer cylinder (1), and a second-stage piston rod (3) slidably nested within the first-stage piston rod (2), characterized in that: The primary piston rod (2) and the secondary piston rod (3) are both hollow tube structures. An earring (11) is fixedly connected to the outer end of the secondary piston rod (3), and a floating piston (13) is arranged inside the secondary piston rod (3); a guide piston sleeve (302) is fixedly connected to the inner wall of the inner end of the secondary piston rod (3), and a damping ring (303) is arranged on the inner wall of the secondary piston rod (3) at a position close to the guide piston sleeve (302); a buffer rod (4) coaxially arranged therewith is fixedly connected to the inner wall of the inner end of the primary piston rod (2), and the buffer rod (4) comprises an intermediate shaft (41), and a step shaft (42) is arranged at the outer end of the intermediate shaft (41), the outer diameter of the step shaft (42) is larger than the outer diameter of the intermediate shaft (41) and smaller than the inner diameter of the damping ring (303), and a buffer rod piston (43) matching the inner diameter of the secondary piston rod (3) is arranged at the outer end of the step shaft (42); the intermediate shaft (41 ) is provided with a flow hole (411) on the circumferential side wall at the outer end, a second communication hole (431) connected to the flow hole (411) is provided on the end surface of the outer end of the buffer rod piston (43), a buffer groove (421) connected to the flow hole (411) is provided on the circumferential outer wall at the inner end of the step shaft (42), the cross-sectional area of ​​the buffer groove (421) decreases towards the buffer rod piston (43), and the variation curve of the cross-sectional area of ​​the buffer groove (421) is approximately a parabola; the guide piston sleeve (302) is slidably nested on the intermediate shaft (41); a buffer oil chamber (16) is formed between the inner wall of the secondary piston rod (3), the outer wall of the buffer rod (4) and the guide piston sleeve (302), and a buffer gas chamber (15) is formed between the inner wall of the secondary piston rod (3), the earring (11) and the floating piston (13), and the buffer oil chamber (16) and the buffer gas chamber (15) are respectively filled with shock-absorbing oil and gas.

2. The multi-stage buffer with a locking structure according to claim 1, characterized in that: A plurality of receiving holes (1) are provided on the circumferential side wall of the inner end of the primary piston rod (2), and a primary locking steel ball (10) is provided in each of the steel ball receiving holes. A locking sleeve structure (1) is provided in the primary piston rod (2) for pressing the primary locking steel ball (10) outwards and causing it to escape from the receiving hole. Primary steel ball locking grooves (101) are provided on the inner wall of the outer end of the outer cylinder (1) at positions corresponding to the primary locking steel balls (10).

3. A multi-stage buffer with a locking structure according to claim 2, characterized in that: The locking sleeve structure comprises a spring seat (6) and a primary locking sleeve (7), wherein the spring seat (6) is threadedly connected to a port at the inner end of the primary piston rod (2), and the primary locking sleeve (7) is slidably nested in the primary piston rod (2) at a position located in the accommodating hole (1), and a concave surface (1) for supporting the bottom end of the primary locking steel ball (10) is provided on the circumferential outer wall of the outer end of the primary locking sleeve (7), and when the primary locking sleeve (7) moves toward the outer end, the concave surface (1) causes the primary locking steel ball (10) to be pushed outward along the radial direction of the outer cylinder (1).

4. A multi-stage buffer with a locking structure according to claim 3, characterized in that: The inner end of the buffer rod (4) is threadedly connected to a positioning flange (9), and the positioning flange (9) is threadedly connected to the inner wall of the primary piston rod (2); a positioning hole is formed on one end surface of the positioning flange (9), and a push rod (91) is slidably embedded in the positioning hole, and the two ends of the push rod (91) are respectively in contact with the outer end of the primary lock sleeve (7) and the inner end surface of the guide piston sleeve (302).

5. The multi-stage buffer with a locking structure according to claim 3, wherein: A micro switch 1 (21) is fixedly provided on the circumferential outer wall of the outer cylinder (1) at a position corresponding to the primary steel ball locking groove (101), and a detection end of the micro switch 1 (21) extends into the primary steel ball locking groove (101).

6. The multi-stage buffer with a locking structure according to claim 1, characterized in that: A second accommodating hole is provided on the circumferential side wall of the outer end of the primary piston rod (2), and a secondary locking steel ball (19) is provided in the steel ball accommodating hole ear, and the outer wall of the secondary piston rod (3) is in contact with the inner wall of the outer end of the primary piston rod (2); a second locking sleeve structure for pressing the secondary locking steel ball (19) inwardly and causing it to escape from the second accommodating hole is provided on the circumferential outer wall of the outer end of the primary piston rod (2), and a secondary steel ball locking groove (304) is provided on the inner wall of the outer end of the secondary piston rod (3) at a position corresponding to the inner side of the secondary locking steel ball (19).

7. A multi-stage buffer with a locking structure according to claim 6, characterized in that: The second locking sleeve structure comprises a second locking sleeve (17) which is provided on the circumferential side wall of the outer end of the first piston rod (2) and can slide in the axial direction thereof, the second locking sleeve (17) being connected to the first piston rod (2) via a third spring (18), and the elastic force generated by the third spring (18) on the second locking sleeve (17) causes it to move toward the outer end of the first piston rod (2); a second concave surface for supporting the top end of the second locking steel ball (19) is provided on the circumferential inner wall of the outer end of the second locking sleeve (17), and when the second locking sleeve (17) moves toward the outer end, the second concave surface causes the second locking steel ball (19) to be pushed out inward along the radial direction of the second piston rod (3).

8. A multi-stage buffer with a locking structure according to claim 6, characterized in that: A second micro switch (20) is fixedly provided on the circumferential side wall of the secondary piston rod (3) at the outer end corresponding to the secondary lock sleeve (17), the detection end of the second micro switch (20) faces the secondary lock sleeve (17), and when the secondary locking steel ball (19) is nested in the secondary steel ball locking groove (304), the secondary lock sleeve (17) moves toward the second micro switch (20).

9. A multi-stage buffer with a locking structure according to claim 1, wherein: The buffer groove (421) is a rectangular groove, and the bottom surface of the buffer groove (421) is an upwardly curved and concave arc surface structure.

10. A multi-stage buffer with a locking structure according to claim 1, characterized in that: A first communication hole (422) is provided on the circumferential side wall of the stepped shaft (42), a detection cavity (412) connected to the first communication hole (422) is provided on the inner end surface of the intermediate shaft (41) along its axial direction, and a temperature and pressure sensor (22) is sealed and fixedly provided in the detection cavity (412).

11. A multi-stage buffer with a locking structure according to claim 1, characterized in that: An oil storage groove (432) is provided on the outer end surface of the buffer rod piston (43), and the second communication holes (431) are all located in the oil storage groove (432).

12. A multi-stage buffer with a locking structure according to claim 3, characterized in that: The inner end of the intermediate shaft (41) is provided with a convex shaft (45), and a locking nut (23) is threadedly connected to the convex shaft (45), and the outer end of the locking nut (23) is in contact with the inner end surface of the positioning flange (9).

13. A multi-stage buffer with a locking structure according to claim 1, characterized in that: A second spring seat (12) which fits against the inner wall of the secondary piston rod (3) is fixedly connected to the inner end of the earring (11), and a second spring (14) is provided between the second spring seat (12) and the floating piston (13). A waterproof and breathable valve (111) which communicates with the buffer air chamber (15) is provided on the earring (11).

14. A multi-stage buffer with a locking structure according to claim 1, characterized in that: A guide key (24) is fixedly provided on the inner wall of the outer cylinder (1) at the outer end. A guide groove (102) is axially formed in the outer wall of the primary piston rod (2) at the position corresponding to the guide key (24).

15. A multi-stage buffer with a locking structure according to claim 1, characterized in that: The damping ring (303) and the secondary piston rod (3) are of an integral structure.

16. The multi-stage buffer with a locking structure according to claim 1, wherein: The damping ring (303) and the secondary piston rod (3) are of a split structure, and receiving grooves are formed at both axial ends of the secondary piston rod (3) corresponding to the damping ring (303). Elastic retaining rings (305) which limit the axial movement of the damping ring (303) are fixedly nested in the receiving grooves.

17. A multi-stage buffer with a locking structure according to claim 1, characterized in that: The outer cylinder (1) is of a hollow tube structure, and an end cap (5) is threadedly connected to the inner end port of the outer cylinder (1). A sealing ring is nested on the circumferential side wall of the end cap (5).

18. A multi-stage buffer with a locking structure according to claim 1, characterized in that: A first guide band (201) is provided on the circumferential outer wall of the primary piston rod (2). The primary piston rod (2) is slidably connected to the inner wall of the outer cylinder (1) through the first guide band (201); a second guide band (301) is provided on the circumferential outer wall of the secondary piston rod (3). The secondary piston rod (3) is slidably connected to the inner wall of the primary piston rod (2) through the second guide band (301).

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