Design method of labyrinth buffer sleeve, buffer structure, hydraulic oil cylinder and hoist

Abstract

The invention relates to the technical field of cushion collar design, and particularly provides a design method of a labyrinth cushion collar, a cushion structure, a hydraulic oil cylinder and a hoist, the design method comprises the following steps: firstly, determining the length, the inner diameter and the outer diameter of the cushion collar according to the size and energy conservation of the hydraulic oil cylinder; secondly, deriving a throttling area curve of the outer surface of the cushion collar according to a force balance equation and a flow equation of a hydraulic oil cylinder piston so as to determine the tapping position of a damping hole in the cushion collar; then the number and the hole diameter of damping holes are determined according to the expected buffer pressure curve and acceleration curve; according to an energy dissipation mechanism and the mathematical model of the cushion collar, the flow resistance series and the flow channel structure of the cushion collar are determined; according to the model, the buffer speed curve and the buffer pressure curve of the buffer sleeve are quickly obtained from the peak pressure and the maximum initial speed, and according to test verification, the method can quickly and accurately design the buffer device meeting the requirement of high-speed heavy-load operation of the quick hydraulic hoist, and the problem that the complex flow channel buffer device is difficult to design and verify is solved.

Description

Technical Field

[0001] This invention relates to the field of buffer sleeve design technology, and in particular to a design method, buffer structure, hydraulic cylinder and gate opener / closer for a labyrinth buffer sleeve. Background Technology

[0002] The main actuator of the fast hydraulic gate opener is a hydraulic cylinder. The piston is pushed by hydraulic oil to extend and retract the piston rod, thereby opening and closing the hydraulic gate opener.

[0003] Existing hydraulic lock hoists primarily focus on developing low-load, low-speed hydraulic cylinder buffering technology, and are largely limited to local optimization of traditional throttling groove or fixed damping orifice buffering structures. This makes it difficult to achieve smooth control of the opening and closing of fast hydraulic lock hoists. Furthermore, in fast hydraulic lock hoists, hydraulic cylinders need to achieve coordinated control of high speed and large load under long stroke conditions. This results in a nonlinear surge in dynamic impact force during the end buffering stage. Under such extreme conditions, conventional buffering structures, due to insufficient energy dissipation capacity or excessive throttling effect, are no longer able to effectively suppress the kinetic energy impact generated by the hydraulic cylinder during the buffering stage.

[0004] Although novel labyrinth-type buffer sleeves (such as a bidirectional buffer cylinder with a metal 3D-printed labyrinth-type buffer sleeve, Chinese Patent Publication No. CN116838664A) can overcome the shortcomings of traditional buffer structures, their design is very complex, and there are problems such as long optimization design cycle and difficulty in verifying design results. Summary of the Invention

[0005] The purpose of this invention is to solve the problem in the prior art of lacking an optimized design method for designing a labyrinth buffer sleeve that has both good throttling effect and strong energy dissipation capability, and to provide a design method, buffer structure, hydraulic cylinder and gate opener for a labyrinth buffer sleeve.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Firstly, a design method for a maze-style cushioning sleeve is provided, comprising the following steps: S1. Based on the parameters of the hydraulic cylinder and the law of conservation of energy, determine the length, inner diameter, and outer diameter of the buffer sleeve; S2. Based on the force balance equation and flow equation of the hydraulic cylinder piston, derive the throttling curve on the outer surface of the buffer sleeve, and thus set the opening position of the damping hole on the buffer sleeve. S3. Determine the number and diameter of damping orifices based on the desired buffer pressure curve, speed curve and acceleration curve of the hydraulic cylinder; S4. Based on the energy dissipation mechanism and the mathematical model of the buffer sleeve, determine the flow resistance series and flow channel structure on the buffer sleeve; S5. Establish a model of the buffer sleeve in the simulation platform, input the peak value of the buffer pressure and the maximum initial velocity of the hydraulic cylinder before entering the buffer, and verify whether the design buffer speed curve and the design buffer pressure curve of the buffer sleeve meet the expected requirements. S6. If all the expected requirements are met, the actual buffer speed curve and the actual buffer pressure curve of the buffer sleeve are obtained by test. If both the actual buffer speed curve and the actual buffer pressure curve meet the requirements, the design of the labyrinth buffer sleeve is completed.

[0007] Preferably, in S1, the length, inner diameter, and outer diameter of the buffer sleeve are initially determined based on the hydraulic cylinder's free stroke, cylinder inner diameter, and piston rod diameter. Then, the peak buffer pressure of the hydraulic cylinder is determined... p cmax ≤ bP 2. The mechanical kinetic energy of moving parts when decelerating and buffering according to the hydraulic cylinder. E 2. All of it is absorbed by the oil and converted into hydraulic energy. E 1. Determine if the length of the buffer sleeve meets the requirements, where, P 2 indicates the pressure in the rodless chamber of the hydraulic cylinder. b For safety reasons, , , , P c Indicates buffer pressure, A c Indicates the effective working area of ​​the buffer cavity. S c Indicates the length of the buffer sleeve. A 2 indicates the effective working area of ​​the rodless chamber of the hydraulic cylinder. m Indicates the equivalent mass of a moving part. v 0 indicates the maximum initial velocity of the hydraulic cylinder before entering the buffer zone. R Indicates load capacity. Preferably, in S1, the length, inner diameter, and outer diameter of the buffer sleeve are initially determined based on the hydraulic cylinder's free stroke, cylinder inner diameter, and piston rod diameter. Then, the peak buffer pressure of the hydraulic cylinder is determined... p cmax ≤ bP 2. The mechanical kinetic energy of moving parts when decelerating and buffering according to the hydraulic cylinder. E 2. All of it is absorbed by the oil and converted into hydraulic energy. E 1. Determine if the length of the buffer sleeve meets the requirements, where, P 2 indicates the pressure in the rodless chamber of the hydraulic cylinder. b For safety reasons, , , , P c Indicates buffer pressure, Ac Indicates the effective working area of ​​the buffer cavity. S c Indicates the length of the buffer sleeve. A 2 indicates the effective working area of ​​the rodless chamber of the hydraulic cylinder. m Indicates the equivalent mass of a moving part. v 0 indicates the maximum initial velocity of the hydraulic cylinder before entering the buffer zone. R Indicates load capacity.

[0008] Preferably, in S2, the force balance equation is: The flow equation is The throttling area curve of the outer surface of the buffer sleeve is as follows: ,in, ρ Indicates the density of hydraulic oil. Indicates the flow coefficient. Q This indicates the flow rate through the damping orifice. v Indicates the speed of the hydraulic cylinder. This indicates the annular gap between the buffer sleeve and the lower end cover. Indicates the diameter of the buffer sleeve. Indicates the acceleration of the hydraulic cylinder. This indicates the displacement of the hydraulic cylinder after it enters the buffer zone.

[0009] Preferably, in S3, the desired buffer pressure curve is expressed as follows: The desired velocity curve is expressed as follows: The desired acceleration curve is expressed as follows: ,in, d Indicates the diameter of the piston rod. , , t The time is represented by the throttling area curve in S2 to obtain the total throttling area. The number and diameter of the damping orifices are then set based on the total throttling area.

[0010] Preferably, in S4, the mathematical model of the buffer sleeve is as follows: and ,in, Q 1 represents the traffic in the first stage. l 0 represents the distance from the start of entering the buffer to the buffer sleeve entering the buffer ring. d 0 indicates the diameter of the damping orifice. This indicates the flow coefficient of the damping orifice. N Indicates the number of damping orifices. This indicates the differential pressure between the buffer chamber and the oil discharge chamber. Q 2 represents the flow rate in the second stage. μ Indicates the viscosity of the hydraulic oil. M This indicates the number of damping orifices that are completely uncovered. AThis represents the area of ​​the damping orifice that is not yet covered. The flow resistance order is obtained based on the mathematical model, and the flow channel structure is set based on the flow resistance order.

[0011] Preferably, the test in S6 includes the following steps: S61. Set a counterweight on one end of the piston rod to lift the upper end of the hydraulic cylinder until the load end touches the ground; S62. Open the rod chamber ball valve to allow the rod chamber oil to flow back to the oil tank; S63. Continue lifting to extend the piston rod until the load end leaves the ground; S64. When the detection cylinder stroke is the full stroke, continue to lift until the load end reaches the preset distance from the ground and then stop; S65. Start oil flow into the rod chamber, and stop oil flow when the piston rod drives the counterweight to rise to the preset height. S66. The piston rod falls freely. Record the falling speed of the piston rod after entering the buffer and the real-time pressure data of the rod chamber. Plot the buffer speed curve and the buffer pressure curve.

[0012] Preferably, in S6, if the actual buffer speed curve and the actual buffer pressure curve meet the requirements of the design buffer speed curve and the design buffer pressure curve respectively, then the design of the labyrinth buffer sleeve is completed.

[0013] Secondly, a buffer structure is provided, which is designed using a labyrinth-style buffer sleeve design method as described above.

[0014] Thirdly, a hydraulic cylinder includes a buffer structure as described above.

[0015] Fourthly, a hydraulic lock opening and closing mechanism includes a hydraulic cylinder as described above.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The design method of the labyrinth-type buffer sleeve described in this invention first determines the length and inner and outer diameters of the buffer sleeve based on the dimensions of the hydraulic cylinder and the law of conservation of energy. Secondly, it derives the throttling area curve of the outer surface of the buffer sleeve based on the force balance equation and flow equation of the hydraulic cylinder piston, thereby determining the position of the damping holes on the buffer sleeve. Then, it determines the number and diameter of the damping holes based on the desired buffer pressure and acceleration curves. Based on the energy dissipation mechanism and the mathematical model of the buffer sleeve, it determines the flow resistance series and flow channel structure of the buffer sleeve. According to its mathematical model, the buffer velocity curve and buffer pressure curve of the buffer sleeve are quickly obtained from the peak pressure and maximum initial velocity. Finally, the design is verified by experiments to ensure it meets the design requirements. This method can quickly and accurately design a buffer device that meets the requirements of high-speed, heavy-load operation of a rapid hydraulic gate opener, solving the problem of difficult design and verification of complex flow channel buffer devices.

[0017] 2. The buffer structure described in this invention enables smooth control of the opening and closing of the lock, ensuring that the buffering effect of the hydraulic cylinder is controllable and adjustable.

[0018] 3. The hydraulic cylinder described in this invention has good energy dissipation capability and good throttling effect, and can effectively suppress the kinetic energy impact generated by the hydraulic cylinder during the buffering stage.

[0019] 4. The hydraulic lock opening and closing machine described in this invention has stable performance, high reliability, and a longer service life. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a design method for a maze-style cushioning sleeve. Figure 2 This is a schematic diagram illustrating the principle of the buffer sleeve; Figure 3 This is a model diagram of the buffer sleeve; Figure 4 This is a schematic diagram of the flow channel; Figure 5 This is a diagram showing the variation of the throttling area along the axial direction; Figure 6 It involves designing a buffer speed curve; Figure 7 It involves designing a buffer pressure curve; Figure 8 This is a schematic diagram of the test for the buffer sleeve.

[0021] Reference numerals: 1-Piston; 2-Piston rod; 3-Buffer sleeve; 4-Lower end cover; 5-Buffer chamber; 6-Annular gap; 7-Oil discharge chamber; 8-Damping hole; 9-Outlet. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings.

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] Unless otherwise specified, the use of terms such as "upper," "lower," "left," "right," "center," "inner," and "outer" to indicate orientation or positional relationships in the description of specific embodiments of the present invention is based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationship in which the product / equipment / device is typically placed during use. These terms are merely for the purpose of facilitating the description of the present invention or simplifying the description in specific embodiments, enabling those skilled in the art to quickly understand the solution, and do not indicate or imply that a particular device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, they should not be construed as limitations on the present invention.

[0025] Furthermore, the use of terms such as "horizontal," "vertical," "suspended," and "parallel" does not imply that the corresponding device / component / element must be absolutely horizontal, vertical, suspended, or parallel, but rather that it can be slightly tilted or have a deviation. For example, "horizontal" merely means that its direction is more horizontal relative to "vertical," not that the structure must be completely horizontal, but that it can be slightly tilted. Alternatively, it can be simplified to mean that the corresponding device / component / element, when set in a "horizontal," "vertical," "suspended," or "parallel" direction, can have an error / deviation of ±10% relative to the corresponding direction, more preferably within ±8%, more preferably within ±6%, more preferably within ±5%, and more preferably within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its function in the present invention.

[0026] Furthermore, the use of terms such as "first," "second," and "third" in terminology is merely for distinguishing descriptions of identical or similar components and should not be interpreted as emphasizing or implying the relative importance of a particular component.

[0027] Furthermore, in the description of the embodiments of the present invention, "several", "more than", and "a number of" represent at least two. The number can be any number, such as 2, 3, 4, 5, 6, 7, 8, or 9, and can even exceed nine.

[0028] Furthermore, in the description of the technical solution of this invention, unless otherwise explicitly specified / limited / restricted, the terms "set up," "install," "connect," "link," "provided with," "laid out," and "arranged" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to common connection methods in the art, such as welding, riveting, bolting, and threaded connections. Such connections can be mechanical, electrical, or communication connections; they can be direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components.

[0029] Example 1 like Figure 1 As shown, the design method of the labyrinth-type buffer sleeve adopted in this invention includes the following steps: S1. Based on the parameters of the hydraulic cylinder and the law of conservation of energy, determine the length, inner diameter, and outer diameter of the buffer sleeve 3; S2. Based on the force balance equation and flow equation of the hydraulic cylinder piston, derive the throttling area curve of the outer surface of the buffer sleeve 3, and thus set the opening position of the damping hole 8 on the buffer sleeve 3. S3. Determine the number and diameter of damping orifices 8 based on the desired buffer pressure curve, speed curve and acceleration curve of the hydraulic cylinder; S4. Based on the energy dissipation mechanism and the mathematical model of buffer sleeve 3, determine the flow resistance series and flow channel structure on buffer sleeve 3. S5. Establish a model of buffer sleeve 3 in the simulation platform, input the peak value of buffer pressure and the maximum initial velocity of the hydraulic cylinder before entering the buffer, and verify whether the design buffer speed curve and design buffer pressure curve of buffer sleeve 3 meet the expected requirements. S6. If all the expected requirements are met, the actual buffer speed curve and the actual buffer pressure curve of the buffer sleeve 3 are obtained by test. If both the actual buffer speed curve and the actual buffer pressure curve meet the requirements, the design of the labyrinth buffer sleeve is completed.

[0030] The buffer sleeve 3 in this design is a labyrinth-style buffer sleeve, such as... Figure 2-4 As shown, its working principle is as follows: When piston 1 moves to the right to the end of its stroke, the buffer sleeve 3 fixed to piston rod 2 gradually approaches the lower end cover 4. The oil in buffer chamber 5 is squeezed out from the annular gap 6 between buffer sleeve 3 and lower end cover 4, that is, the flow area of ​​oil from buffer chamber 5 to oil discharge chamber 7 decreases, resulting in an increase in pressure in buffer chamber 5. When piston 1 continues to move to the right, buffer sleeve 3 is inserted into lower end cover 4, forcing oil to flow in from the damping hole 8 on the outer circumference of buffer sleeve 3 and out from the outlet 9 of buffer sleeve 3. The oil discharge resistance increases, thereby effectively slowing down the running speed of the hydraulic cylinder and achieving buffering.

[0031] In S1, based on the hydraulic cylinder's free stroke, cylinder inner diameter, and piston rod 2 diameter, the length, inner diameter, and outer diameter of the buffer sleeve 3 are initially determined. Then, based on the peak buffer pressure of the hydraulic cylinder... p cmax ≤ bP 2. The mechanical kinetic energy of moving parts when decelerating and buffering according to the hydraulic cylinder. E 2. All of it is absorbed by the oil and converted into hydraulic energy. E 1. Determine whether the length of the buffer sleeve 3 meets the requirements, where, P 2 indicates the pressure in the rodless chamber of the hydraulic cylinder. bFor safety, a factor of 1.5 can be used. Buffer 3 is a variable orifice buffer; the buffer pressure is highest when it first enters the buffer. , , , P c Indicates buffer pressure, A c This indicates the effective working area of ​​buffer cavity 5. S c This indicates the length of buffer sleeve 3. A 2 indicates the effective working area of ​​the rodless chamber of the hydraulic cylinder. m Indicates the equivalent mass of a moving part. v 0 indicates the maximum initial velocity of the hydraulic cylinder before entering the buffer zone. R Indicates load capacity.

[0032] In S2, the force balance equation is: The flow equation is The throttling area curve of the outer surface of the buffer sleeve 3 is derived as follows: , is a parabolic curve, such as Figure 5 As shown, the flow area of ​​the damping hole 8 of the buffer sleeve 3 is initially large, and then gradually decreases as the buffering process progresses. ρ Indicates the density of hydraulic oil. This represents the flow coefficient, which is calculated from a table by looking up the area ratio of the cross-sections before and after the contraction channel. A value of 0.67 to 0.742 can be used in the calculation. Q This indicates the flow rate through damping orifice 8. v Indicates the speed of the hydraulic cylinder. This indicates the annular gap 6 between the buffer sleeve 3 and the lower end cover 4. This indicates the diameter of buffer sleeve 3. Indicates the acceleration of the hydraulic cylinder. This indicates the displacement of the hydraulic cylinder after it enters the buffer zone.

[0033] In S3, the desired buffer pressure curve is expressed as follows: The desired velocity curve is expressed as follows: The desired acceleration curve is expressed as follows: ,in, d This indicates the diameter of piston rod 2. , , t The time is represented by the throttling area curve in S2 to obtain the total throttling area. The number and diameter of the damping orifices 8 are then set based on the total throttling area.

[0034] In S4, the mathematical model of buffer sleeve 3 is: and ,in, Q1 indicates the flow rate in the first stage (before entering the buffer stage). l 0 indicates the distance from the start of entering the buffer to the buffer sleeve 3 entering the buffer ring, which is located at the entrance of the lower end cover 4 (not shown). d 0 indicates the diameter of damping orifice 8. This represents the flow coefficient of damping orifice 8, which can be taken as 0.6~0.8 in calculations. N Indicates the number of damping orifices 8. This indicates the pressure difference between the buffer chamber 5 and the oil discharge chamber 7. The pressure in the oil discharge chamber 7 can be assumed to be atmospheric pressure. Q 2 indicates the flow rate in the second stage (entering the buffer stage). μ Indicates the viscosity of the hydraulic oil. M This indicates the number of damping orifices 8 that are completely uncovered. A This represents the area of ​​the damping orifice 8 that is not yet covered. The flow resistance level is set according to the length of the buffer sleeve 3 in the mathematical model and considering the smoothness of the throttling curve. The cross-sectional shape and aperture of the flow channel structure are set according to the flow resistance level. Multiple buffer channels can be set along the circumference of the buffer sleeve 3 in each level. The number of buffer channels is limited by the size of the circumference diameter. In this embodiment, only the internal flow channel is circular. Other common cross-sectional shapes such as square, ellipse, and trapezoid can also be applied to the design of buffer channels.

[0035] In S5, the MATLAB program can be run as follows: % MATLAB Script: Calculation of the runtime state of a buffer structure clc; clear % ===== Constant parameter definition ===== Ac = 0.132; % Effective working area of ​​the buffer cavity (m^2) Sc = 0.28; % Buffer structure length (m) = 280mm P2 = 8e6;% Rodless chamber pressure (Pa) A2 = 0.181; % Rodless cavity effective area (m^2) m = 70e3;% Mass of moving parts (kg) R = 60e3 * 9.81; % Load capacity (N) % ===== User Input ===== Pcmax = input('Please enter the peak pressure Pcmax (unit: MPa): ') * 1e6; % Convert to Pa v0 = input('Please enter the initial velocity v0 (unit: m / s): '); % ===== Calculate the initial working pressure Pc ===== Pc = Pcmax - (m*v0^2) / (2*Ac * Sc); % Unit is Pa fprintf('Initial working pressure Pc = %.2f MPa\n', Pc / 1e6); % ===== Initialize simulation parameters ===== t_end = 1.5; % Simulation time (seconds) dt = 0.001; % Time step (seconds) N = floor(t_end / dt); % Initialize array t = zeros(N,1); V = zeros(N,1); Pc_array = zeros(N,1); % Initial conditions V(1) = V0; Pc_array(1) = Pc; % ===== Euler Integral Speed ​​and Pressure ===== for i = 1:N-1 % Estimate acceleration using current velocity dVdt = (Pc_array(i)*Ac - P2*A2 - R) / m; % Update speed V(i+1) = V(i) + dVdt * dt; % Update workload (based on the Pcmax equation) Pc_array(i+1) = Pcmax - (m * V(i+1)^2) / (2 * Ac * Sc); % Update time t(i+1) = t(i) + dt; end % ===== Drawing ===== figure subplot(2,1,1); plot(t, V, 'b'); xlabel('Time(s)'); ylabel('velocity V (m / s)'); title('Velocity changes over time'); subplot(2,1,2); plot(t, Pc_array / 1e6, 'r'); xlabel('Time(s)'); ylabel('Working pressure Pc (MPa)'); title('Work stress changes over time'); The design buffer velocity curve and design buffer pressure curve obtained from the simulation are respectively referred to as follows: Figures 6-7 .

[0036] The tests in S6 can be conducted using methods such as... Figure 8 The method includes the following steps: S61. Set a counterweight on one end of the piston rod 2 to lift the upper end of the hydraulic cylinder until the load end touches the ground; S62. Open the rod chamber ball valve to allow the rod chamber oil to flow back to the oil tank, even if YV4 is energized; S63. Continue lifting to extend piston rod 2 until the load end leaves the ground; S64. When the cylinder stroke is detected to be full stroke, continue lifting until the load end reaches the preset distance from the ground and then stop. The detection can be done using an opening meter. After the crane stops lifting, maintain the vertical stability of the cylinder. At this time, the cylinder should be in the state where the piston rod 2 is fully extended. S65. Start oil intake in the rod chamber. Stop oil intake when the piston rod 2 drives the counterweight to the preset height. That is, start the hydraulic system pump during the test, adjust the pressure of the relief valve, so that the electromagnet YV2 is energized. When the piston rod drives the weight to the design stroke, the oil pump stops working and all electromagnets are de-energized. At this time, the oil cylinder is at the design stroke position, and the oil cylinder is confirmed to be in a vertical and stable state. S66. Start data recording and perform buffer sleeve performance test. Electromagnet YV4 is energized, piston rod 2 falls freely, record the falling speed of piston rod 2 after entering the buffer and the real-time pressure data of the rod chamber, and plot the buffer speed curve and buffer pressure curve.

[0037] If the actual buffer speed curve and the actual buffer pressure curve meet the requirements of the design buffer speed curve and the design buffer pressure curve respectively, then the design of the labyrinth buffer sleeve is complete.

[0038] The design method of the labyrinth-type buffer sleeve described in this invention enables the rapid and accurate design of a buffer device that meets the requirements of high-speed and heavy-load operation of a rapid hydraulic gate hoist, solving the problem of difficult design and verification of complex flow channel buffer devices.

[0039] Example 2 like Figure 3 As shown, the buffer structure of this embodiment is designed using a labyrinth-type buffer sleeve design method as described in Embodiment 1.

[0040] The buffer structure described in this invention enables smooth control of the opening and closing of the lock, ensuring that the buffering effect of the hydraulic cylinder is controllable and adjustable.

[0041] Example 3 One embodiment of the hydraulic cylinder includes a buffer structure as described in Embodiment 2.

[0042] Example 4 This embodiment of a hydraulic lock opening and closing mechanism includes a hydraulic cylinder as described in Embodiment 3.

[0043] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A design method for a maze-type cushioning sleeve, characterized in that, Includes the following steps: S1. Based on the parameters of the hydraulic cylinder and the law of conservation of energy, determine the length, inner diameter and outer diameter of the buffer sleeve (3); S2. Based on the force balance equation and flow equation of the hydraulic cylinder piston, derive the throttling area curve of the outer surface of the buffer sleeve (3), and thus set the opening position of the damping hole (8) on the buffer sleeve (3). S3. Determine the number and diameter of the damping holes (8) based on the desired buffer pressure curve, speed curve and acceleration curve of the hydraulic cylinder. S4. Based on the energy dissipation mechanism and the mathematical model of the buffer sleeve (3), determine the flow resistance series and flow channel structure on the buffer sleeve (3); S5. Establish a model of the buffer sleeve (3) in the simulation platform, input the peak value of the buffer pressure and the maximum initial velocity of the hydraulic cylinder before entering the buffer, and verify whether the design buffer speed curve and the design buffer pressure curve of the buffer sleeve (3) meet the expected requirements. S6. If all the expected requirements are met, the actual buffer speed curve and the actual buffer pressure curve of the buffer sleeve (3) are obtained by test. If both the actual buffer speed curve and the actual buffer pressure curve meet the requirements, the design of the labyrinth buffer sleeve is completed.

2. The design method of a labyrinth-type buffer sleeve according to claim 1, characterized in that, In S1, based on the hydraulic cylinder's free stroke, cylinder inner diameter, and piston rod (2) diameter, the length, inner diameter, and outer diameter of the buffer sleeve (3) are initially determined. Then, based on the hydraulic cylinder's buffer pressure peak value... p cmax ≤ bP 2. The mechanical kinetic energy of moving parts when decelerating and buffering according to the hydraulic cylinder. E 2. All of it is absorbed by the oil and converted into hydraulic energy. E 1. Determine whether the length of the buffer sleeve (3) meets the requirements, wherein, P 2 indicates the pressure in the rodless chamber of the hydraulic cylinder. b For safety reasons, , , , P c Indicates buffer pressure, A c This indicates the effective working area of ​​the buffer cavity (5). S c This indicates the length of the buffer sleeve (3). A 2 indicates the effective working area of ​​the rodless chamber of the hydraulic cylinder. m Indicates the equivalent mass of a moving part. v 0 indicates the maximum initial velocity of the hydraulic cylinder before entering the buffer zone. R Indicates load capacity.

3. The design method of a labyrinth-type buffer sleeve according to claim 2, characterized in that, In S2, the force balance equation is: The flow equation is The throttling area curve of the outer surface of the buffer sleeve (3) is as follows: ,in, ρ Indicates the density of hydraulic oil. Indicates the flow coefficient. Q This indicates the flow rate through the damping orifice (8). v Indicates the speed of the hydraulic cylinder. This indicates the annular gap (6) between the buffer sleeve (3) and the lower end cover (4). This indicates the diameter of the buffer sleeve (3). Indicates the acceleration of the hydraulic cylinder. This indicates the displacement of the hydraulic cylinder after it enters the buffer zone.

4. The design method of a labyrinth-type buffer sleeve according to claim 3, characterized in that, In S3, the desired buffer pressure curve is expressed as follows: The desired velocity curve is expressed as follows: The desired acceleration curve is expressed as follows: ,in, d This indicates the diameter of the piston rod (2). , , t The time is represented by the throttling area curve in S2 to obtain the total throttling area. The number and diameter of the damping orifices (8) are set according to the total throttling area.

5. The design method of a labyrinth-type buffer sleeve according to claim 4, characterized in that, In S4, the mathematical model of the buffer sleeve (3) is: and ,in, Q 1 represents the traffic in the first stage. l 0 indicates the distance from the start of entering the buffer to the buffer sleeve (3) entering the buffer ring. d 0 represents the diameter of the damping orifice (8). This represents the flow coefficient of the damping orifice (8). N Indicates the number of damping orifices (8), This indicates the differential pressure between the buffer chamber (5) and the oil discharge chamber (7). Q 2 represents the flow rate in the second stage. μ Indicates the viscosity of the hydraulic oil. M This indicates the number of damping orifices (8) that are completely uncovered. A The area of ​​the damping orifice (8) that is not yet covered is represented by the number of flow resistance levels obtained from the mathematical model. The flow channel structure is set according to the number of flow resistance levels.

6. A design method for a labyrinth-type buffer sleeve according to any one of claims 1-5, characterized in that, The experiment in S6 includes the following steps: S61. Set a counterweight on one end of the piston rod (2) to lift the upper end of the hydraulic cylinder until the load end is in contact with the ground; S62. Open the rod chamber ball valve to allow the rod chamber oil to flow back to the oil tank; S63, continue lifting to extend the piston rod (2) until the load end leaves the ground; S64. When the detection cylinder stroke is the full stroke, continue to lift until the load end reaches the preset distance from the ground and then stop; S65, start oil intake into the rod chamber, and stop oil intake when the piston rod (2) drives the counterweight to rise to the preset height; S66. The piston rod (2) falls freely. Record the falling speed of the piston rod (2) after entering the buffer and the real-time pressure data of the rod chamber. Plot the buffer speed curve and the buffer pressure curve.

7. A design method for a labyrinth-type buffer sleeve according to any one of claims 1-5, characterized in that, In S6, if the actual buffer speed curve and the actual buffer pressure curve meet the requirements of the design buffer speed curve and the design buffer pressure curve respectively, then the design of the labyrinth buffer sleeve is completed.

8. A buffer structure, characterized in that, The design adopts the design method of a labyrinth-type buffer sleeve as described in any one of claims 1-7.

9. A hydraulic cylinder, characterized in that, Includes a buffer structure as described in claim 8.

10. A hydraulic lock opening and closing mechanism, characterized in that, Including a hydraulic cylinder as described in claim 9.

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