Spring bi-directional cushioned single-acting multi-cylinder

Abstract

The utility model discloses a single -action multi -connected cylinder of spring two -way buffer, including through the oil circuit and communicate in proper order a plurality of single -unit oil cylinder, and each single -unit oil cylinder includes cylinder body, piston rod, guide sleeve and buffer structure, buffer structure is located in the piston rod end, and buffer structure divides the cylinder body inside into rodless chamber and rod chamber, and the cylinder body of first -stage single -unit oil cylinder is equipped with rod chamber oil port, and rod chamber oil port is connected with rodless chamber, and the rodless chamber of lower stage single -unit oil cylinder is connected with the rod chamber of upper stage single -unit oil cylinder. Buffer structure includes the positioning sleeve, spring and piston who are arranged in proper order along the piston rod extension direction and with piston rod sliding cooperation, and buffer cavity is formed between positioning sleeve and piston, and positioning sleeve and cylinder body have radial clearance, and the piston has the through -hole of axial penetration on. The utility model can improve the moving speed of piston rod in each single -unit oil cylinder, and can reduce hydraulic impact force.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder design technology, and in particular to a single-acting multi-cylinder with bidirectional spring buffer. Background Technology

[0002] Hydraulic cylinders, especially high-pressure hydraulic cylinders, usually have buffer structures at both ends of the piston rod's stroke to prevent the piston rod from hitting the cylinder barrel and causing abnormal noise, unstable starting, high pressure build-up, and other problems. With the development of the industry, many OEMs are now pursuing lightweight design, stability, and user experience, especially in the aerial work platform industry. In order to ensure lightweight design and a good user experience, customers will require us to design hydraulic cylinders with compact space and front and rear buffers.

[0003] The hydraulic cylinder disclosed in patent number CN116658486A achieves bidirectional buffering through the cooperation of two buffer sleeves and springs. Compared with the traditional structure with buffer grooves at both ends, the space is more compact. However, because this patent forms a closed cavity with the two buffer sleeves to improve the buffering effect, the hydraulic oil can only flow through the oil passage holes on the outer periphery of the buffer sleeves. This causes a significant reduction in the oil intake speed of the subsequent two-stage cylinders, affecting the extension and retraction speed of the final-stage piston rod. In addition, during the reciprocating motion of the buffer sleeves, there is friction between the contact surface between the buffer sleeves and the cylinder barrel, resulting in frictional losses and affecting the service life of the buffer sleeves.

[0004] Therefore, how to design a multi-cylinder that can achieve both bidirectional buffering and improve the hydraulic oil flow rate of each stage of the cylinder is a technical problem that needs to be solved. Utility Model Content

[0005] To address the technical problems of slow hydraulic oil flow and low extension and retraction speed of the final stage piston rod in existing bidirectional buffer multi-cylinders, this invention provides a single-acting multi-cylinder with bidirectional spring buffer to solve the above problems.

[0006] This utility model proposes a single-acting multi-stage cylinder with bidirectional spring buffer, comprising multiple individual cylinders connected sequentially by an oil circuit. Each individual cylinder includes a cylinder body, a guide sleeve, a piston rod, and a buffer structure. The buffer structure is located at the end of the piston rod and divides the cylinder body into a rodless chamber and a rod chamber. The cylinder body of the first-stage individual cylinder is provided with a rod chamber oil port, which is connected to the rodless chamber. The rodless chamber of the next-stage individual cylinder is connected to the rod chamber of the previous-stage individual cylinder. The buffer structure includes a positioning sleeve, a spring, and a piston arranged sequentially along the extension direction of the piston rod and slidingly engaged with the piston rod. A buffer cavity is formed between the positioning sleeve and the piston. The positioning sleeve has a radial clearance with the cylinder body. The piston has an axially penetrating through hole.

[0007] In an optional embodiment of this utility model, the cylinder body includes a cylinder barrel and a cylinder bottom that seals the end of the cylinder barrel, and the cylinder bottom has a buffer groove into which the piston rod extends.

[0008] In an optional embodiment of this utility model, the buffer structure is disposed near the end of the piston rod facing the bottom of the cylinder.

[0009] In an optional embodiment of this utility model, both the piston and the positioning sleeve are annular cylinders.

[0010] In an optional embodiment of this utility model, the outer peripheral surface of the piston is provided with helical grooves extending to both ends of the piston.

[0011] In an optional embodiment of this utility model, the piston rod includes a large-diameter section and a small-diameter section facing the bottom of the cylinder. The end of the small-diameter section is threaded with a nut. The outer diameter of the nut is smaller than the inner diameter of the buffer groove. The buffer structure is located between the large-diameter section and the nut.

[0012] In an optional embodiment of this invention, the cross-section of the rodless cavity is larger than the cross-section of the rod cavity.

[0013] In an optional embodiment of this utility model, the single cylinder further includes a fixed seat fixed to the extended end of the piston rod. The piston rod has a radial oil passage and an axial oil passage extending from the end of the radial oil passage to the end of the piston rod. Hydraulic oil enters through the fixed seat and enters the rodless chamber through the radial oil passage and the axial oil passage.

[0014] In an optional embodiment of this utility model, the piston rod includes a rod body and a rod head located at one end of the rod body. The radial oil passage is located inside the rod head, and the rod head is connected to the fixed seat. The axial oil passage includes a coarse oil passage and fine oil passages located at both ends of the coarse oil passage. The fine oil passage connected to the radial oil passage is located inside the rod head.

[0015] The beneficial effects of this utility model are: (1) This utility model improves the two buffer sleeves that are nested together in the prior art into a piston and a positioning sleeve, and sets multiple oil passage holes on the piston so that the hydraulic oil can be connected to the two side cavities through the oil passage holes, thereby improving the flow speed of the hydraulic oil. This can both increase the moving speed of the piston rod in each stage of the single cylinder and reduce the hydraulic impact force.

[0016] (2) The present invention has a spiral groove on the outer periphery of the piston, which can lubricate the contact surface between the piston and the cylinder and reduce friction loss. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1This is a schematic diagram of the structure of the first-stage single-unit hydraulic cylinder in this utility model; Figure 2 This is a partial enlarged view of the buffer structure in a specific embodiment of the single-acting multi-cylinder with bidirectional spring buffer described in this utility model. Figure 3 This is a schematic diagram of the piston structure in this utility model.

[0019] In the diagram, 1. Single hydraulic cylinder, 2. Cylinder body, 201. Cylinder barrel, 202. Cylinder bottom, 2021. Buffer groove, 3. Piston rod, 301. Coarse diameter section, 302. Fine diameter section, 4. Rodless chamber, 5. Rod chamber, 6. Rod chamber oil port, 7. Positioning sleeve, 8. Spring, 9. Piston, 901. Helical groove, 10. Buffer chamber, 11. Radial clearance, 12. Through hole, 13. Fixed seat, 14. Radial oil passage, 15. Axial oil passage, 1501. Coarse oil passage, 1502. Fine oil passage, 16. Connecting oil pipe, 17. Rod body, 18. Rod head, 19. Guide sleeve, 20. Nut. Detailed Implementation

[0020] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0021] Example 1: As Figures 1-3 As shown, a single-acting multi-cylinder with spring bidirectional buffer includes multiple individual cylinders 1 connected sequentially via oil circuits. Figure 2 The diagram shows a partial view of a multi-cylinder system consisting of three-stage individual cylinders 1. Each individual cylinder 1 includes a cylinder body 2, a piston rod 3, a guide sleeve 19, and a buffer structure. The buffer structure is located at the end of the piston rod 3 and divides the interior of the cylinder body 2 into a rodless chamber 4 and a rod chamber 5. The cylinder body 2 of the first-stage individual cylinder 1 is provided with a rod chamber oil port 6, which is connected to the rodless chamber 4. The rodless chamber 4 of the next-stage individual cylinder 1 is connected to the rod chamber 5 of the previous-stage individual cylinder 1.

[0022] When preparing to extend piston rod 3, hydraulic oil enters rodless chamber 4 from rod chamber port 6 of the first-stage unit cylinder 1, thereby pushing piston rod 3 out. Simultaneously, some hydraulic oil leaks through the buffer structure into rod chamber 5 and then into rodless chamber 4 of the next-stage unit cylinder 1 (e.g., ...). Figure 1As shown, the cylinder body 2 has a connecting oil pipe 16 that connects the rod chamber 5 of the previous stage single-unit cylinder 1 to the rodless chamber 4 of the next stage single-unit cylinder 1, and so on, until the rod chamber 5 of the last stage single-unit cylinder 1 is reached. The rod chamber 5 of the last stage single-unit cylinder 1 has no outlet. When it is necessary to retract the piston rod 3, the hydraulic oil is squeezed out by pushing the piston rod 3 with external force. The cross-sectional area of ​​the rodless chamber 4 is preferably larger than the cross-sectional area of ​​the rod chamber 5, so that the hydraulic oil can still push the piston rod 3 while flowing into the rod chamber 5.

[0023] The buffer structure includes a positioning sleeve 7, a spring 8, and a piston 9 arranged sequentially along the extension direction of the piston rod 3 and slidingly engaged with the piston rod 3. The inner circumferential surfaces of the positioning sleeve 7 and the piston 9 are slidably engaged with the piston rod 3. The positioning sleeve 7 serves to limit the end of the spring 8. A buffer cavity 10 is formed between the positioning sleeve 7 and the piston 9. The positioning sleeve 7 has a radial clearance 11 with the cylinder body 2. The piston 9 has an axially penetrating through hole 12. When the piston rod 3 is fully retracted, the positioning sleeve 7 abuts against one end of the cylinder body 2 and compresses the spring 8 to form a buffer. When the piston rod 3 is fully extended, the piston 9 abuts against the other end of the cylinder body 2 and compresses the spring 8 to form a buffer.

[0024] Within the buffer structure, the radial clearance 11 between the positioning sleeve 7 and the cylinder body 2, the buffer cavity 10, and the through hole 12 form a channel communicating with the rod cavity 5 and the rodless cavity 4. Compared to the prior art, which relies solely on the oil passage hole on the outer periphery of the buffer sleeve for communication, the radial clearance 11 between the positioning sleeve 7 and the cylinder body 2, as well as the areas of the buffer cavity 10 and the through hole 12, are larger in this invention. Therefore, the flow rate of hydraulic oil can be greatly increased, which helps the hydraulic oil to flow quickly between the individual cylinders 1 and improves the movement speed of the piston rod 3. At the same time, the rapid flow of hydraulic oil can reduce the hydraulic thrust received at the end of the buffer structure, so the buffering force does not need to be large, and the buffering effect can be achieved even if there is no sealed cavity inside the buffer structure.

[0025] More specifically, the cylinder body 2 includes a cylinder barrel 201 and a cylinder bottom 202 that seals the end of the cylinder barrel 201. The cylinder bottom 202 has a buffer groove 2021 into which the piston rod 3 extends. When the piston rod 3 retracts to the bottom, the positioning sleeve 7 of the buffer structure contacts the cylinder bottom 202, and the end of the piston rod 3 enters the buffer groove 2021. As the spring 8 contracts, the piston rod 3 gradually moves into the buffer groove 2021.

[0026] The buffer structure is axially limited by the positioning sleeve 7, piston 9, and nut 20. For ease of installation, the buffer structure is preferably located near the end of the piston rod 3. In this embodiment, the buffer structure is located at the end of the piston rod 3 facing the cylinder bottom 202. Specifically, the piston rod 3 includes a large-diameter section 301 and a small-diameter section 302. The end of the small-diameter section 302 facing the cylinder bottom 202 is threadedly connected to the nut 20. The outer diameter of the nut 20 is smaller than the inner diameter of the buffer groove 2021. The buffer structure is located between the large-diameter section 301 and the nut 20. To disassemble or assemble the buffer structure, simply remove the nut 20.

[0027] Both piston 9 and positioning sleeve 7 are annular cylinders and do not contact each other. Alternatively, an inner guide sleeve can be provided at the opposite ends of piston 9 and positioning sleeve 7 to provide inner guidance for spring 8.

[0028] Example 2: Based on the above examples, such as... Figure 2 and Figure 3 As shown, the outer circumferential surface of the piston 9 is provided with spiral grooves 901 extending to both ends of the piston 9. When the cylinder is working, hydraulic oil can enter the spiral grooves 901. Since the spiral grooves 901 extend spirally on the outer circumferential surface of the piston 9, rather than being limited to certain fixed arcs, the hydraulic oil can cover the entire inner circumferential surface of the cylinder 201 during the reciprocating motion of the piston 9, thereby providing lubrication for the contact surface between the piston 9 and the cylinder 201, reducing frictional loss, and improving the service life of the piston 9.

[0029] Example 3: Based on the above examples, the single-unit cylinder 1 further includes a fixed seat 13 fixed to the extended end of the piston rod 3. The piston rod 3 has a radial oil passage 14 and an axial oil passage 15 extending from the end of the radial oil passage 14 to the end of the piston rod 3. Hydraulic oil enters through the fixed seat 13 and then enters the rodless chamber 4 through the radial oil passage 14 and the axial oil passage 15. The end of the radial oil passage 14 refers to the intersection point of multiple radial oil passages 14 at the center of the piston rod 3. The axial oil passage design of the piston rod 3 allows the oil inlet position of the rodless chamber 4 to be moved from the cylinder bottom 202 to the outside of the cylinder body 2, facilitating the installation of the oil inlet pipe. It also separates the relatively moving parts of adjacent single-unit cylinders 1. Specifically, the cylinder body 2 of the preceding single-unit cylinder 1 moves synchronously with the fixed seat 13 of the following single-unit cylinder 1, while the cylinder bodies 2 of adjacent single-unit cylinders do not move synchronously. If oil enters through the cylinder bottom 202, motion interference will occur.

[0030] In further design, such as Figure 1As shown, the piston rod 3 is manufactured in two parts, including a rod body 17 and a rod head 18 located at one end of the rod body 17. The rod body 17 and the rod head 18 are welded and fixed. The radial oil passage 14 is located inside the rod head 18. The rod head 18 is connected to the fixed seat 13. The axial oil passage 15 includes a coarse oil passage 1501 and a fine oil passage 1502 located at both ends of the coarse oil passage 1501. The fine oil passage 1502 connected to the radial oil passage 14 is located inside the rod head 18. Since the piston rod 3 is relatively long, it is difficult to machine a small hole (i.e., fine oil passage 1502) in the whole section. It is easy to deviate and damage the drill bit. Therefore, a coarse hole (i.e., coarse oil passage 1501) is machined on the left side of the rod body 17 first, and then a small hole is drilled on the right side to facilitate machining.

[0031] In this specification, the illustrative expressions of the terms do not necessarily refer to the same embodiments. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments.

[0032] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A single-acting multi-cylinder with spring bidirectional buffer, characterized in that: It includes multiple individual hydraulic cylinders connected sequentially by oil circuits. Each individual hydraulic cylinder includes a cylinder body, a guide sleeve, a piston rod, and a buffer structure. The buffer structure is located at the end of the piston rod and divides the cylinder body into a rodless chamber and a rod chamber. The cylinder body of the first-stage individual hydraulic cylinder is provided with a rod chamber oil port, which is connected to the rodless chamber. The rodless chamber of the next-stage individual hydraulic cylinder is connected to the rod chamber of the previous-stage individual hydraulic cylinder. The buffer structure includes a positioning sleeve, a spring, and a piston arranged sequentially along the extension direction of the piston rod and slidingly engaged with the piston rod. A buffer cavity is formed between the positioning sleeve and the piston. The positioning sleeve has a radial clearance with the cylinder body. The piston has an axially penetrating through hole.

2. The single-acting multi-cylinder with spring bidirectional buffer according to claim 1, characterized in that: The cylinder body includes a cylinder barrel and a cylinder bottom that seals the end of the cylinder barrel, the cylinder bottom having a buffer groove into which the piston rod extends.

3. The single-acting multi-cylinder with spring bidirectional buffer according to claim 2, characterized in that: The buffer structure is located near the end of the piston rod facing the bottom of the cylinder.

4. The single-acting multi-cylinder with spring bidirectional buffer according to claim 1, characterized in that: Both the piston and the positioning sleeve are annular cylinders.

5. The single-acting multi-cylinder with spring bidirectional buffer according to claim 4, characterized in that: The outer circumferential surface of the piston is provided with helical grooves extending to both ends of the piston.

6. The single-acting multi-cylinder with spring bidirectional buffer according to claim 2, characterized in that: The piston rod includes a large-diameter section and a small-diameter section facing the bottom of the cylinder. The end of the small-diameter section is threaded with a nut. The outer diameter of the nut is smaller than the inner diameter of the buffer groove. The buffer structure is located between the large-diameter section and the nut.

7. The single-acting multi-cylinder with spring bidirectional buffer according to claim 1, characterized in that: The cross-section of the rodless cavity is larger than that of the rod cavity.

8. The single-acting multi-cylinder with spring bidirectional buffer according to claim 1, characterized in that: The single-unit cylinder also includes a fixed seat fixed to the extended end of the piston rod. The piston rod has a radial oil passage and an axial oil passage extending from the end of the radial oil passage to the end of the piston rod. Hydraulic oil enters through the fixed seat and then enters the rodless cavity through the radial oil passage and the axial oil passage.

9. The single-acting multi-cylinder with spring bidirectional buffer according to claim 8, characterized in that: The piston rod includes a rod body and a rod head located at one end of the rod body. The radial oil passage is located inside the rod head, and the rod head is connected to the fixed seat. The axial oil passage includes a coarse oil passage and fine oil passages located at both ends of the coarse oil passage. The fine oil passages connected to the radial oil passage are located inside the rod head.

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