Multi-stage linear oil cylinder with unilateral oil inlet and outlet structure

Abstract

The application discloses a kind of single-sided oil inlet and outlet structure's multistage linear oil cylinder, including main cylinder body, first piston body is equipped in main cylinder body, first piston rod is installed on first piston body;Second piston body is equipped in first piston rod, second piston rod is installed on second piston body, and antenna flange assembly is installed in the end of second piston rod;One end of main cylinder body is installed with oil circuit component, and oil circuit component includes first oil pipe and second oil pipe, and the both ends of first piston body are respectively equipped with first chamber and second chamber;The both ends of second piston body are respectively equipped with third chamber and fourth chamber, and first chamber and third chamber are mutually communicated;Second oil pipe is sleeved and installed outside first oil pipe, and first oil pipe is communicated with second chamber, and second oil pipe is communicated with fourth chamber.The application is supplied with oil in multiple chambers by single oil circuit component, and installation is convenient;Oil pipe component is built-in in main cylinder body and fixedly installed, and the structure is more stable and can avoid pipeline mutual entanglement.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic actuation technology, specifically relating to a multi-stage linear hydraulic cylinder with a single-sided oil inlet and outlet structure. Background Technology

[0002] Multi-stage hydraulic cylinders consist of multiple cascaded pistons. Each piston is driven by hydraulic oil to achieve axial movement. The pistons at each stage are connected in series via connecting rods or sleeves, forming a multi-stage telescopic structure. A patent with publication number CN115744707B discloses a heavy-duty, long-stroke lifting and leveling device and method. Internally, it uses a multi-stage cylinder drive, and externally, multiple overlapping sleeves balance the lateral load. The cylinders are inverted, using the outer cylinder barrel to replace the final sleeve. A weighing sensor is installed at the bottom to monitor the load in real time. Ultimately, it achieves long-stroke lifting and leveling of heavy-duty equipment under limited closed-loop dimensions. Existing conventional multi-stage hydraulic cylinders have independent inlet and outlet oil lines for each stage, resulting in a complex structure. Due to the numerous oil lines, any oil leakage can lead to cylinder failure, resulting in poor reliability. Furthermore, the oil lines of existing cylinders are externally mounted, making them prone to damage during prolonged use in various environments, limiting their application scenarios and versatility. Therefore, a multi-stage linear hydraulic cylinder with a single-sided inlet and outlet oil structure is needed to overcome these difficulties. Summary of the Invention

[0003] To address the problems existing in the prior art, this invention designs a multi-stage linear hydraulic cylinder with a single-sided oil inlet and outlet structure. This invention achieves oil supply in multiple chambers through a single oil circuit component, which is convenient to install and highly integrated. At the same time, the oil pipe assembly is built into the main cylinder body and fixedly installed, making the structure more stable and avoiding the pipes from getting tangled.

[0004] The objective of this invention is achieved through the following technical solution: a multi-stage linear hydraulic cylinder with a single-sided oil inlet and outlet structure, comprising a main cylinder body, a first piston body capable of telescoping relative to it, and a first piston rod mounted on the first piston body; a second piston body capable of telescoping relative to it is located within the first piston rod, a second piston rod mounted on the second piston body, and an antenna flange assembly mounted at the end of the second piston rod; an oil passage assembly is mounted at one end of the main cylinder body, the oil passage assembly including a first oil pipe and a second oil pipe; a first chamber and a second chamber are respectively located at both ends of the first piston body; a third chamber and a fourth chamber are respectively located at both ends of the second piston body, the first chamber and the third chamber being interconnected; the second oil pipe is sleeved and installed outside the first oil pipe, the first oil pipe connecting to the second chamber, and the second oil pipe connecting to the fourth chamber.

[0005] Preferably, a cylinder seat is installed at one end of the main cylinder body, and a first cylinder cover assembly is installed at the other end; one end of the first piston rod is sealed to the first piston body, and a second cylinder cover assembly is installed at the other end of the first piston rod; the oil circuit assembly further includes a first transfer pipe and a second transfer pipe, both of which are disposed in the cylinder seat; the first transfer pipe is connected to the first oil pipe, and the second transfer pipe is connected to the first chamber.

[0006] Preferably, the first piston body has a first through hole extending axially therefrom; the two ends of the first piston body have a first chamber and a second chamber, the second chamber being disposed on the outer layer of the second piston body; one side of the second piston body has a third chamber facing the first chamber, and the first through hole connects the first chamber and the third chamber; the first cylinder head assembly includes a first cylinder head body, the first cylinder head body being disposed between the first piston rod and the main cylinder body; an O-ring is provided between the first cylinder head body and the main cylinder body, and a pair of stoichiometric seals are provided between the first cylinder head body and the first piston rod. The first cylinder head assembly includes a pair of guide support rings between the first cylinder head body and the first piston rod, and one of the Sterling seals has a dustproof ring on its side. The second cylinder head assembly includes a second cylinder head body, which is disposed between the first piston rod and the second piston rod. An O-ring is provided between the second cylinder head body and the first piston rod, and a pair of Sterling seals are provided between the second cylinder head body and the second piston rod. A pair of guide support rings are also provided between the second cylinder head body and the second piston rod, and one of the Sterling seals has a dustproof ring on its side.

[0007] By setting a cylinder seat, it is convenient to position and install the hydraulic circuit assembly at one end of the main cylinder body; the second transfer pipe is set in the cylinder seat and connects to the first chamber; a first piston body is provided between the first chamber and the third chamber, and the first piston body has a first through hole, so that hydraulic oil can flow from the first chamber to the third chamber; in the initial state, hydraulic oil enters the first chamber from the second transfer pipe. Since the diameter of the first through hole is small, the hydraulic oil will first gather in the first chamber and then flow from the first chamber to the third chamber; when the first chamber is full of hydraulic oil, the first piston rod extends; when the third chamber is full of hydraulic oil, the second piston rod extends; since the first chamber and the third chamber can be filled with hydraulic oil at the same time, the first piston rod and the second piston rod can extend in the same direction in sequence; since the first piston body is sealed to the main cylinder body, hydraulic oil cannot enter the second chamber at this time; the second piston body is also sealed to the first piston rod, so hydraulic oil cannot enter the fourth chamber at this time. By installing a first cylinder head assembly, a seal is formed between the first piston rod and the second chamber, while also improving the concentricity of the first piston rod during extension and retraction. This seal is achieved using a Ster seal, with a dust ring isolating impurities, and a guide ring providing limiting guidance for the first piston rod. Similarly, a second cylinder head assembly is installed to seal between the second piston rod and the fourth chamber.

[0008] Preferably, the outer wall of the first piston body is sealed to the inner wall of the main cylinder, and the outer wall of the second piston body is sealed to the inner wall of the first piston rod; one end of the first oil pipe is installed on the first transfer pipe, and the other end of the first oil pipe is inserted into the first piston body; the first piston body is also provided with a second oil pipe threaded to it, the second oil pipe is sleeved on the outer layer of the first oil pipe, and a gap is left between the first oil pipe and the second oil pipe.

[0009] Preferably, the first piston body has a first vertical channel that connects to the first oil pipe, and the two ends of the first vertical channel have paired first horizontal channels; the first piston body also has a first inlet / outlet channel that connects to the first vertical channel, and a gap is left between the first inlet / outlet channel and the outer wall of the first oil pipe; one of the first horizontal channels has a first check valve assembly, and the other first horizontal channel has a second check valve assembly, and the first check valve assembly and the second check valve assembly are arranged in opposite directions.

[0010] Preferably, both the first and second one-way valve assemblies include a compression spring, a nylon ball, and a drilled fastening screw; the drilled fastening screw is installed at the end of the first horizontal channel, and the nylon ball on the first one-way valve assembly abuts against the hole of the drilled fastening screw; one end of the compression spring on the first one-way valve assembly abuts against the nylon ball, and the other end of the compression spring on the first one-way valve assembly abuts against the inner wall of the first horizontal channel; one end of the compression spring on the second one-way valve assembly abuts against the drilled fastening screw, and the other end of the compression spring on the second one-way valve assembly abuts against the nylon ball, and the nylon ball on the second one-way valve assembly abuts against the inner wall of the first horizontal channel.

[0011] Preferably, a piston gasket is fixedly installed at the end of the first piston body facing the first chamber, a Glad seal is provided between the piston gasket and the first piston body, a guide support ring is provided between the first piston body and the first oil pipe, and an O-ring is provided between the second oil pipe and the first inlet / outlet channel of the first piston body.

[0012] By setting up a first oil pipe and a second oil pipe, hydraulic oil can be easily injected into the second and fourth chambers, thereby enabling precise control of the contraction state of the first and second piston bodies. Since hydraulic oil can be injected into the second and fourth chambers simultaneously, the first and second piston rods can contract sequentially in the same direction. Hydraulic oil enters the first oil pipe from the first transfer line. Due to the gap between the first and second oil pipes, the hydraulic oil can enter the first vertical channel from the first inlet / outlet channel, and then enter the two first horizontal channels from the first vertical channel. At this time, hydraulic oil needs to be injected into the second chamber, causing the first piston body to contract. Hydraulic oil enters the second chamber from the first vertical channel, so the first one-way valve assembly is closed and the second one-way valve assembly is open. Hydraulic oil then enters the second chamber from the first horizontal channel where the second one-way valve assembly is located, causing the first piston body to contract. When the first piston body extends, the hydraulic oil in the second chamber flows back. At this time, the first one-way valve assembly opens and the second one-way valve assembly closes, allowing the hydraulic oil to flow back from the second chamber along the first horizontal channel into the first oil pipe. By setting a piston gasket, the Glyd seal on the first piston body is limited; by setting a Glyd seal, the first oil pipe and the first piston body have better sealing performance; by setting a guide support ring, the first oil pipe and the first piston body are coaxially arranged, and no deflection gap is generated between them, resulting in better overall sealing performance, thereby preventing hydraulic oil in the second chamber from leaking into the first chamber.

[0013] Preferably, the second piston body is slidably installed inside the first piston rod, and the second piston body is provided with a second horizontal channel and a second vertical channel that are interconnected; a gap is left between the outer wall of the second oil pipe and the inner wall of the second piston rod, and the second piston body is also provided with a second inlet and outlet channel; one end of the second inlet and outlet channel is connected to the second vertical channel, and the other end of the second inlet and outlet channel is connected to the second oil pipe; a gap is left between the second inlet and outlet channel and the second oil pipe, and the second oil pipe is interconnected with the fourth chamber.

[0014] Preferably, a piston gasket is fixedly installed at the end of the second piston body facing the third chamber, a Glad seal is provided between the piston gasket and the second piston body, and a guide support ring is provided between the second piston body and the second oil pipe.

[0015] Preferably, the end of the second piston rod is provided with an antenna flange assembly that is sealed to it; the outer layers of the main cylinder, the first piston rod, and the second piston rod are all fitted with protective sleeves, and each protective sleeve is located on the same side of the main cylinder; the antenna flange assembly is provided with an oil unloading channel that communicates with the fourth chamber, and a sealing plug is installed at the end of the oil unloading channel.

[0016] Hydraulic oil enters the second oil pipe from the first oil pipe. A gap exists between the second oil pipe and the second piston rod, allowing the hydraulic oil to flow along the second inlet / outlet channel into the second vertical channel, and then from the second vertical channel along the second horizontal channel into the fourth chamber. When the fourth chamber is full of hydraulic oil, the second piston body contracts. When the second piston body extends, the hydraulic oil in the fourth chamber flows back into the second oil pipe along the second inlet / outlet channel, and then from the second oil pipe back into the first oil pipe. By incorporating a Gladley seal and a guide support ring on the second piston body, better density is achieved between the second piston body and the second oil pipe, preventing hydraulic oil leakage from the fourth chamber into the third chamber. An oil discharge channel facilitates the release of hydraulic oil from the second piston rod and allows for adjustment of the hydraulic oil capacity.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can synchronously control the movement of the first piston body and the second piston body through a set of first and second transfer pipes on the oil circuit assembly; 2. The first and second transfer pipes are set on the same side of the main cylinder, avoiding the oil pipes from tangling together, reducing the risk of wear and fatigue fracture, and greatly improving the reliability of the oil cylinder; 3. Since there is only one set of first and second transfer pipes, the potential leakage risk during pipeline installation is reduced, making installation more convenient and use more reliable; 4. Both the first and second piston bodies are provided with flow channels, which facilitates the flow of hydraulic oil between the first oil pipe and the second chamber, and at the same time, the hydraulic oil can also flow between the first oil pipe and the fourth chamber, thus controlling the contraction state of the first and second piston bodies; 5. Through the cooperation of the first and second oil pipes, oil can be supplied to the second and fourth chambers; both the first and second oil pipes are internally installed, making the structure more compact and space-saving; 6. Since both the first and second oil pipes are internally installed, they can be used in various working environments, with better versatility. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention; Figure 2 This is a perspective view of the invention from another angle; Figure 3 This is a schematic diagram of the internal structure of the present invention; Figure 4 for Figure 3 A magnified view of a portion of position A in the middle; Figure 5 for Figure 3 Enlarged view of position B in the middle Figure 6 This is a schematic diagram of the structure of the first and second transfer pipelines; Figure 7 This is a schematic diagram of the internal structure of the first piston body; Figure 8 This is a schematic diagram of the internal structure of the second piston body; The markings in the diagram are as follows: 1. Main cylinder body; 2. First piston body; 201. First through hole; 202. First vertical channel; 203. First horizontal channel; 204. First inlet / outlet channel; 3. First piston rod; 4. Second piston body; 41. Second horizontal channel; 42. Second vertical channel; 43. Second inlet / outlet channel; 5. Second piston rod; 6. Antenna flange assembly; 61. Oil unloading channel; 62. Sealing plug; 7. Oil circuit assembly; 71. First oil pipe; 72. Second oil pipe; 73. First transfer pipe; 74. Second transfer pipe. 8. First chamber; 9. Second chamber; 10. Third chamber; 11. Fourth chamber; 12. Cylinder seat; 13. First cylinder head assembly; 131. First cylinder head body; 14. Second cylinder head assembly; 141. Second cylinder head body; 15. O-ring seal; 16. Sterling seal; 17. Guide support ring; 18. Dust seal; 19. First check valve assembly; 20. Second check valve assembly; 21. Compression spring; 22. Nylon ball; 23. Drilled fastener screw; 24. Piston gasket; 25. Glyd seal; 26. Sheath. Detailed Implementation

[0019] The present invention will be further described below with reference to the embodiments illustrated in the accompanying drawings: like Figures 1 to 8 As shown, this embodiment discloses a multi-stage linear hydraulic cylinder with a single-sided oil inlet and outlet structure, including a main cylinder body 1. A first piston body 2, which is retractable relative to the main cylinder body 1, is provided within the main cylinder body 1. A first piston rod 3 is mounted on the first piston body 2. A second piston body 4, which is retractable relative to the first piston rod 3, is provided within the first piston rod 3. A second piston rod 5 is mounted on the second piston body 4, and an antenna flange assembly 6 is mounted at the end of the second piston rod 5. An oil passage assembly 7 is installed at one end of the main cylinder body 1. The oil passage assembly 7 includes a first oil pipe 71 and a second oil pipe 72. A first chamber 8 and a second chamber 9 are respectively provided at both ends of the first piston body 2. A third chamber 10 and a fourth chamber 11 are respectively provided at both ends of the second piston body 4. The first chamber 8 and the third chamber 10 are interconnected. The second oil pipe 72 is sleeved and installed outside the first oil pipe 71. The first oil pipe 71 connects to the second chamber 9, and the second oil pipe 72 connects to the fourth chamber 11.

[0020] One end of the main cylinder body 1 is equipped with a cylinder seat 12, and the other end is equipped with a first cylinder cover assembly 13; one end of the first piston rod 3 is sealed to the first piston body 2, and the other end of the first piston rod 3 is equipped with a second cylinder cover assembly 14; the oil circuit assembly 7 also includes a first transfer pipe 73 and a second transfer pipe 74, both of which are disposed in the cylinder seat 12; the first transfer pipe 73 is connected to the first oil pipe 71, and the second transfer pipe 74 is connected to the first chamber 8. The first piston body 2 is provided with a first through hole 201 extending axially therefrom; the two ends of the first piston body 2 are provided with a first chamber 8 and a second chamber 9, the second chamber 9 being disposed on the outer layer of the second piston body 4; a third chamber 10 is provided on one side of the second piston body 4 facing the first chamber 8, and the first through hole 201 connects the first chamber 8 and the third chamber 10; the first cylinder head assembly 13 includes a first cylinder head body 131, the first cylinder head body 131 being disposed between the first piston rod 3 and the main cylinder body 1; an O-ring seal 15 is provided between the first cylinder head body 131 and the main cylinder body 1, and a pair of Sterling seals 16 are provided between the first cylinder head body 131 and the first piston rod 3; the... A pair of guide support rings 17 are provided between the first cylinder head body 131 and the first piston rod 3, and a dustproof ring 18 is provided on the side of one of the Sterling seals 16; the second cylinder head assembly 14 includes a second cylinder head body 141, which is disposed between the first piston rod 3 and the second piston rod 5; an O-ring seal 15 is provided between the second cylinder head body 141 and the first piston rod 3, and a pair of Sterling seals 16 are provided between the second cylinder head body 141 and the second piston rod 5; a pair of guide support rings 17 are also provided between the second cylinder head body 141 and the second piston rod 5, and a dustproof ring 18 is provided on the side of one of the Sterling seals 16.

[0021] The outer wall of the first piston body 2 is sealed to the inner wall of the main cylinder 1, and the outer wall of the second piston body 4 is sealed to the inner wall of the first piston rod 3; one end of the first oil pipe 71 is installed on the first transfer pipe 73, and the other end of the first oil pipe 71 is inserted into the first piston body 2; the first piston body 2 is also provided with a second oil pipe 72 threadedly connected to it, and the second oil pipe 72 is sleeved on the outer layer of the first oil pipe 71, with a gap between the first oil pipe 71 and the second oil pipe 72. The first piston body 2 is provided with a first vertical channel 202 that connects to the first oil pipe 71. The two ends of the first vertical channel 202 are provided with a pair of first horizontal channels 203. The first piston body 2 is also provided with a first inlet / outlet channel 204 that connects to the first vertical channel 202 and leaves a gap between the first inlet / outlet channel 204 and the outer wall of the first oil pipe 71. One of the first horizontal channels 203 is provided with a first check valve assembly 19 and the other first horizontal channel 203 is provided with a second check valve assembly 20. The first check valve assembly 19 and the second check valve assembly 20 are arranged in opposite directions. Both the first one-way valve assembly 19 and the second one-way valve assembly 20 include a compression spring 21, a nylon ball 22, and a drilled fastening screw 23. The drilled fastening screw 23 is installed at the end of the first horizontal channel 203, and the nylon ball 22 on the first one-way valve assembly 19 abuts against the hole of the drilled fastening screw 23. One end of the compression spring 21 on the first one-way valve assembly 19 abuts against the nylon ball 22, and the other end of the compression spring 21 on the first one-way valve assembly 19 abuts against the inner wall of the first horizontal channel 203. One end of the compression spring 21 on the second one-way valve assembly 20 abuts against the drilled fastening screw 23, and the other end of the compression spring 21 on the second one-way valve assembly 20 abuts against the nylon ball 22, and the nylon ball 22 on the second one-way valve assembly 20 abuts against the inner wall of the first horizontal channel 203. A piston gasket 24 is fixedly installed at the end of the first piston body 2 facing the first chamber 8. A Glad seal 25 is provided between the piston gasket 24 and the first piston body 2. A guide support ring 17 is provided between the first piston body 2 and the first oil pipe 71. An O-ring 15 is provided between the second oil pipe 72 and the first inlet / outlet channel 204 of the first piston body 2.

[0022] The second piston body 4 is slidably mounted inside the first piston rod 3. The second piston body 4 has a second horizontal channel 41 and a second vertical channel 42 that are interconnected. A gap exists between the outer wall of the second oil pipe 72 and the inner wall of the second piston rod 5. The second piston body 4 also has a second inlet / outlet channel 43. One end of the second inlet / outlet channel 43 is connected to the second vertical channel 42, and the other end is connected to the second oil pipe 72. A gap exists between the second inlet / outlet channel 43 and the second oil pipe 72, and the second oil pipe 72 is interconnected with the fourth chamber 11. A piston gasket 24 is fixedly mounted on the end of the second piston body 4 facing the third chamber 10. A Gladley seal 25 is provided between the piston gasket 24 and the second piston body 4. A guide support ring 17 is provided between the second piston body 4 and the second oil pipe 72. The end of the second piston rod 5 is provided with an antenna flange assembly 6 that is sealed to it; the outer layers of the main cylinder 1, the first piston rod 3 and the second piston rod 5 are all equipped with sheaths 26, and each sheath 26 is located on the same side of the main cylinder 1; the antenna flange assembly 6 is provided with an oil unloading channel 61 that communicates with the fourth chamber 11, and a sealing plug 62 is installed at the end of the oil unloading channel 61.

[0023] The specific operation process of this embodiment is as follows: By setting the cylinder seat 12, it is convenient to position and install the oil circuit assembly 7 at one end of the main cylinder body 1; the second transfer pipe 74 is set in the cylinder seat 12 and connects to the first chamber 8; a first piston body 2 is provided between the first chamber 8 and the third chamber 10, and a first through hole 201 is provided on the first piston body 2, so that hydraulic oil can flow from the first chamber 8 to the third chamber 10; in the initial state, hydraulic oil enters the first chamber 8 from the second transfer pipe 74. Since the diameter of the first through hole 201 is small, the hydraulic oil will first gather in the first... Hydraulic oil flows from the first chamber 8 to the third chamber 10. When the first chamber 8 is full of hydraulic oil, the first piston rod 3 extends. When the third chamber 10 is full of hydraulic oil, the second piston rod 5 extends. Since the first chamber 8 and the third chamber 10 can be filled with hydraulic oil simultaneously, the first piston rod 3 and the second piston rod 5 can extend in the same direction sequentially. Because the first piston body 2 is sealed to the main cylinder 1, hydraulic oil cannot enter the second chamber 9 at this time. The second piston body 4 is also sealed to the first piston rod 3, so hydraulic oil cannot enter the fourth chamber 11 at this time. By setting the first cylinder cover assembly 13, the first piston rod 3 and the second chamber 9 are sealed, and the first piston rod 3 has better concentricity when it extends and retracts. Here, the seal is achieved by the Ster seal 16, and impurities are isolated by the dust ring 18. The first piston rod 3 is limited and guided by the guide support ring 17. Similarly, by setting the second cylinder cover assembly 14, the second piston rod 5 and the fourth chamber 11 are sealed.

[0024] By setting up the first oil pipe 71 and the second oil pipe 72, hydraulic oil can be easily injected into the second chamber 9 and the fourth chamber 11, thereby enabling precise control of the contraction state of the first piston body 2 and the second piston body 4. Since hydraulic oil can be injected into the second chamber 9 and the fourth chamber 11 simultaneously, the first piston rod 3 and the second piston rod 5 can contract sequentially in the same direction. Hydraulic oil enters the first oil pipe 71 from the first transfer pipe 73. Due to the gap between the first oil pipe 71 and the second oil pipe 72, the hydraulic oil can enter the first vertical channel 202 from the first inlet / outlet channel 204, and then enter the two first horizontal channels 203 from the first vertical channel 202. Since hydraulic oil needs to be injected into the second chamber 9 at this time, the first piston body 2 contracts. At this time, the hydraulic oil flows from the first inlet / outlet channel 204 into the second vertical channel 202 into the two first horizontal channels 203. A vertical channel 202 enters the second chamber 9, thus closing the first check valve assembly 19 and opening the second check valve assembly 20. Hydraulic oil then enters the second chamber 9 through the first horizontal channel 203 where the second check valve assembly 20 is located, causing the first piston body 2 to contract. When the first piston body 2 extends, the hydraulic oil in the second chamber 9 flows back. At this time, the first check valve assembly 19 opens, and the second check valve assembly 20 closes, allowing the hydraulic oil to flow back from the second chamber 9 along the first horizontal channel 203 into the first oil pipe 71. A piston gasket 24 limits the movement of the Gladley seal 25 on the first piston body 2. The Gladley seal 25 improves the sealing between the first oil pipe 71 and the first piston body 2. A guide support ring 17 ensures that the first oil pipe 71 and the first piston body 2 are coaxially aligned, preventing any deflection gap and improving overall sealing, thus preventing hydraulic oil leakage from the second chamber 9 into the first chamber 8.

[0025] Hydraulic oil enters the second oil pipe 72 from the first oil pipe 71. A gap exists between the second oil pipe 72 and the second piston rod 5, allowing the hydraulic oil to enter the second vertical channel 42 along the second inlet / outlet channel 43, and then enter the fourth chamber 11 from the second vertical channel 42 along the second horizontal channel 43. When the fourth chamber 11 is filled with hydraulic oil, the second piston body 4 retracts. When the second piston body 4 extends, the hydraulic oil in the fourth chamber 11 flows back into the second oil pipe 72 along the second inlet / outlet channel 43, and then flows back into the first oil pipe 71 from the second oil pipe 72. By installing a Gladley seal 25 and a guide support ring 17 on the second piston body 4, better density is achieved between the second piston body 4 and the second oil pipe 72, preventing hydraulic oil leakage from the fourth chamber 11 into the third chamber 10. The oil discharge channel 61 facilitates the release of hydraulic oil from the second piston rod 5 and allows for adjustment of the hydraulic oil capacity.

[0026] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure, comprising a main cylinder body (1), characterized in that, The main cylinder (1) is provided with a first piston body (2) that can extend and retract relative to it, and a first piston rod (3) is installed on the first piston body (2); the first piston rod (3) is provided with a second piston body (4) that can extend and retract relative to it, and a second piston rod (5) is installed on the second piston body (4), and an antenna flange assembly (6) is installed at the end of the second piston rod (5); an oil circuit assembly (7) is installed at one end of the main cylinder (1), the oil circuit assembly (7) includes a first oil pipe (71) and a second oil pipe (72), and a first chamber (8) and a second chamber (9) are respectively provided at both ends of the first piston body (2); the second piston... The body (4) has a third chamber (10) and a fourth chamber (11) at its two ends, respectively, and the first chamber (8) and the third chamber (10) are interconnected; the second oil pipe (72) is sleeved and installed outside the first oil pipe (71), the first oil pipe (71) is connected to the second chamber (9), and the second oil pipe (72) is connected to the fourth chamber (11); the oil circuit assembly (7) also includes a first transfer pipe (73) and a second transfer pipe (74), both of which are located inside the cylinder seat (12); the first transfer pipe (73) and the first oil pipe (71) are connected to the first oil pipe (71). The first piston body (2) is connected to the second transfer pipe (74) and the first chamber (8); one end of the first oil pipe (71) is installed on the first transfer pipe (73), and the other end of the first oil pipe (71) is inserted into the first piston body (2); the first piston body (2) is also provided with a second oil pipe (72) threadedly connected to it, and the second oil pipe (72) is sleeved on the outer layer of the first oil pipe (71), with a gap between the first oil pipe (71) and the second oil pipe (72); the first piston body (2) is provided with a first vertical channel (202) for connecting the first oil pipe (71), and the first vertical channel (202) is connected to the first oil pipe (71). The first horizontal channel (203) is provided in pairs at both ends of the channel (202); the first piston body (2) is also provided with a first inlet and outlet channel (204), the first inlet and outlet channel (204) is connected to the first vertical channel (202), and there is a gap between the first inlet and outlet channel (204) and the outer wall of the first oil pipe (71); a first one-way valve assembly (19) is provided in one of the first horizontal channels (203), and a second one-way valve assembly (20) is provided in the other first horizontal channel (203), and the first one-way valve assembly (19) and the second one-way valve assembly (20) are arranged in opposite directions.

2. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 1, characterized in that, One end of the main cylinder body (1) is equipped with a cylinder seat (12), and the other end is equipped with a first cylinder cover assembly (13); one end of the first piston rod (3) is sealed to the first piston body (2), and the other end of the first piston rod (3) is equipped with a second cylinder cover assembly (14).

3. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 2, characterized in that, The first piston body (2) is provided with a first through hole (201) extending axially therein; the first piston body (2) is provided with a first chamber (8) and a second chamber (9) at both ends, the second chamber (9) being disposed on the outer layer of the second piston body (4); the second piston body (4) is provided with a third chamber (10) on one side facing the first chamber (8), the first through hole (201) connecting the first chamber (8) and the third chamber (10); the first cylinder head assembly (13) includes a first cylinder head body (131), the first cylinder head body (131) being disposed between the first piston rod (3) and the main cylinder body (1); an O-ring (15) is provided between the first cylinder head body (131) and the main cylinder body (1), and a pair of Sterling seals (16) are provided between the first cylinder head body (131) and the first piston rod (3). The first cylinder head body (131) and the first piston rod (3) are provided with a pair of guide support rings (17), and one of the Ster seals (16) is provided with a dustproof ring (18) on its side; the second cylinder head assembly (14) includes a second cylinder head body (141), which is disposed between the first piston rod (3) and the second piston rod (5); an O-ring (15) is provided between the second cylinder head body (141) and the first piston rod (3), and a pair of Ster seals (16) are provided between the second cylinder head body (141) and the second piston rod (5); a pair of guide support rings (17) are provided between the second cylinder head body (141) and the second piston rod (5), and one of the Ster seals (16) is provided with a dustproof ring (18) on its side.

4. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 2, characterized in that, The outer wall of the first piston body (2) is sealed to the inner wall of the main cylinder (1), and the outer wall of the second piston body (4) is sealed to the inner wall of the first piston rod (3).

5. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 4, characterized in that, Both the first one-way valve assembly (19) and the second one-way valve assembly (20) include a compression spring (21), a nylon ball (22), and a drilled fastening screw (23); the drilled fastening screw (23) is installed at the end of the first horizontal channel (203), and the nylon ball (22) on the first one-way valve assembly (19) abuts against the hole of the drilled fastening screw (23); one end of the compression spring (21) on the first one-way valve assembly (19) abuts against the nylon ball (22). The other end of the compression spring (21) on the first one-way valve assembly (19) abuts against the inner wall of the first horizontal channel (203); one end of the compression spring (21) on the second one-way valve assembly (20) abuts against the drilled fastening screw (23), and the other end of the compression spring (21) on the second one-way valve assembly (20) abuts against the nylon ball (22), and the nylon ball (22) on the second one-way valve assembly (20) abuts against the inner wall of the first horizontal channel (203).

6. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 4, characterized in that, A piston gasket (24) is fixedly installed at the end of the first piston body (2) facing the first chamber (8). A Gly seal (25) is provided between the piston gasket (24) and the first piston body (2). A guide support ring (17) is provided between the first piston body (2) and the first oil pipe (71). An O-ring (15) is provided between the second oil pipe (72) and the first inlet / outlet channel (204) of the first piston body (2).

7. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 4, characterized in that, The second piston body (4) is slidably installed inside the first piston rod (3). The second piston body (4) is provided with a second horizontal channel (41) and a second vertical channel (42) that are mutually connected. There is a gap between the outer wall of the second oil pipe (72) and the inner wall of the second piston rod (5). The second piston body (4) is also provided with a second inlet and outlet channel (43). One end of the second inlet and outlet channel (43) is connected to the second vertical channel (42), and the other end of the second inlet and outlet channel (43) is connected to the second oil pipe (72). There is a gap between the second inlet and outlet channel (43) and the second oil pipe (72). The second oil pipe (72) is mutually connected to the fourth chamber (11).

8. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 7, characterized in that, A piston gasket (24) is fixedly installed on the end of the second piston body (4) facing the third chamber (10). A Glad seal (25) is provided between the piston gasket (24) and the second piston body (4). A guide support ring (17) is provided between the second piston body (4) and the second oil pipe (72).

9. The multi-stage linear hydraulic cylinder with a single-sided oil inlet / outlet structure according to claim 1, characterized in that, The end of the second piston rod (5) is provided with an antenna flange assembly (6) that is sealed to it; the outer layers of the main cylinder (1), the first piston rod (3) and the second piston rod (5) are all equipped with sheaths (26), and each sheath (26) is located on the same side of the main cylinder (1); the antenna flange assembly (6) is provided with an oil unloading channel (61) that communicates with the fourth chamber (11), and a sealing plug (62) is installed at the end of the oil unloading channel (61).

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