Multi-stroke hydraulic oil cylinder

Abstract

The utility model relates to the technical field of hydraulic machines, in particular to a multi-stroke hydraulic oil cylinder. The piston assembly is arranged in the cylinder body assembly in a sliding mode, the cylinder body assembly comprises a first cylinder barrel and a second cylinder barrel located above the first cylinder barrel, the piston assembly comprises a first piston, a second piston, a first piston rod, a second piston rod and a piston fixing ring, and the first piston, the first piston rod and the second piston rod are sequentially arranged in the cylinder body assembly from bottom to top. The first piston and the first piston rod are located in the first cylinder barrel, the second piston and the second piston rod are located in the second cylinder barrel, an oil port A is formed in the bottom of the first cylinder barrel, an oil port B is formed in the bottom of the second cylinder barrel, and an oil port C is formed in the top of the second cylinder barrel. Through cooperative control of the multiple plug cavities and the multiple oil ports, single-oil-cylinder multi-stroke actions are achieved, and tasks can be completed only through one oil cylinder in long-stroke operation. The device is simple and compact in structure and small in occupied space, the equipment complexity and the production cost are remarkably reduced, and meanwhile the production efficiency is improved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic press technology, and in particular to a multi-stroke hydraulic cylinder. Background Technology

[0002] Current hydraulic press cylinders typically employ a single-stroke structure, relying on the hydraulic system to control the inflow and outflow of oil in a single chamber and port to drive the cylinder's movement. This design is adequate for short-stroke applications with ample space. However, for long-stroke operations, dual-position cylinders are usually required, resulting in bulky equipment, higher manufacturing costs, and relatively lower work efficiency. This is especially problematic in complex working environments with limited space. This invention achieves multi-stroke operation with a single cylinder through the coordinated control of multiple chambers and ports, allowing for task completion with only one cylinder in long-stroke applications. This invention features a simple and compact structure, minimal space occupation, significantly reducing equipment complexity and production costs while simultaneously improving production efficiency. Utility Model Content

[0003] The purpose of this utility model is to solve the problems existing in the prior art by proposing a multi-stroke hydraulic cylinder.

[0004] To achieve the above objectives, the present invention adopts the following technical solution:

[0005] A multi-stroke hydraulic cylinder includes a cylinder body assembly and a piston assembly. The piston assembly is slidably disposed inside the cylinder body assembly. The cylinder body assembly includes a first cylinder barrel and a second cylinder barrel located above the first cylinder barrel. The piston assembly includes a first piston, a second piston, a first piston rod, a second piston rod, and a piston retaining ring. The first piston, the first piston rod, and the second piston rod are arranged sequentially from bottom to top inside the cylinder body assembly. The first piston and the first piston rod are located inside the first cylinder barrel, and the second piston and the second piston rod are located inside the second cylinder barrel.

[0006] Furthermore, the top surface of the piston one is in contact with the bottom surface of the piston rod one, and the top end of the piston rod one is fixedly connected to the bottom end of the piston rod two by threads.

[0007] Furthermore, the piston rod 2 has a piston retaining ring and piston 2 fixedly connected sequentially from bottom to top on its bottom outer ring.

[0008] Furthermore, the top surface of cylinder one and the bottom surface of cylinder two are in contact with each other and are fixedly connected by a fixed flange one located on the outer ring of the top of cylinder one and a fixed flange two located on the outer ring of the bottom of cylinder two.

[0009] Furthermore, the bottom of the first cylinder is provided with an oil port A, and the bottom of the second cylinder is provided with an oil port B and the top is provided with an oil port C.

[0010] Furthermore, a cylinder port is fixed to the inner ring at the junction of the top surface of cylinder one and the bottom surface of cylinder two. The inner diameter of cylinder port one is larger than the outer diameter of piston rod one and piston rod two at the junction with it, and the inner diameter of cylinder port one is smaller than the outer diameter of piston one and piston retaining ring.

[0011] Furthermore, the bottom surface of the cylinder is connected to a cylinder bottom, the lower part of the cylinder bottom is a cylinder and the upper part is a ring, the connection between the cylinder and the ring is an arc shape, and the top surface of the cylinder bottom is in contact with the bottom surface of the piston.

[0012] Furthermore, the inner ring of the top of the second cylinder is fixed with a cylinder port lock nut and a second cylinder port in sequence from top to bottom, and the outer ring of the top of the second cylinder is fixedly connected with a locking flange.

[0013] Compared with existing technologies, the multi-stroke hydraulic cylinder provided by this utility model has the following advantages:

[0014] 1. Highly adaptable, especially suitable for working environments with long strokes and limited space;

[0015] 2. Multi-stroke working capability, improving equipment flexibility;

[0016] 3. Cost savings and reduced manufacturing costs;

[0017] 4. Improve efficiency, speed up workflows, and increase overall production efficiency. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0019] Figure 2 This is a cross-sectional view of the present invention;

[0020] Figure 3 This is a three-dimensional sectional view of the cylinder bottom structure of this utility model;

[0021] In the diagram: 11. Cylinder barrel 1, 12. Cylinder barrel 2, 13. Fixed flange 1, 14. Fixed flange 2, 15. Cylinder bottom, 16. Cylinder port 1, 17. Cylinder port 2, 18. Cylinder port lock nut, 19. Locking flange, 21. Piston 1, 22. Piston 2, 23. Piston rod 1, 24. Piston rod 2, 25. Piston retaining ring. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0024] Example 1, as shown in the accompanying drawings. Figures 1-2 As shown, a multi-stroke hydraulic cylinder includes a cylinder body assembly and a piston assembly. The piston assembly is slidably disposed inside the cylinder body assembly. The cylinder body assembly includes a first cylinder 11 and a second cylinder 12 located above the first cylinder 11. The piston assembly includes a first piston 21, a second piston 22, a first piston rod 23, a second piston rod 24, and a piston retaining ring 25. The first piston 21, the first piston rod 23, and the second piston rod 24 are arranged sequentially from bottom to top inside the cylinder body assembly. The first piston 21 and the first piston rod 23 are located inside the first cylinder 11, and the second piston 22 and the second piston rod 24 are located inside the second cylinder 12.

[0025] The top surface of piston 21 is in contact with the bottom surface of piston rod 23, and the top end of piston rod 23 is fixedly connected to the bottom end of piston rod 24 by threads.

[0026] The piston rod 24 has a piston retaining ring 25 and piston 22 fixedly connected to its bottom outer ring from bottom to top.

[0027] In this embodiment, the upper part of the piston rod 24 is a large-diameter part and the lower part is a small-diameter part. The piston retaining ring 25 is sleeved on the small-diameter part and contacts the bottom surface of the large-diameter part. The piston retaining ring 25 is fixed to the piston rod 24 by threads and abuts against the bottom surface of the piston 22.

[0028] Through the cooperation of piston rod 24 and piston retaining ring 25, piston 22 is fixedly connected to the outer ring of piston rod 24, and piston rod 24 is in turn fixedly connected to piston rod 23 by threads. Therefore, piston 22, piston rod 23, piston rod 24 and piston retaining ring 25 form an integral structure, thereby achieving synchronous movement.

[0029] Example 2, as shown in the accompanying drawings. Figures 1-2 As shown, the top surface of cylinder 11 and the bottom surface of cylinder 2 are in contact with each other and are fixedly connected by a fixing flange 13 located on the top outer ring of cylinder 11 and a fixing flange 14 located on the bottom outer ring of cylinder 2.

[0030] A cylinder port 16 is fixed to the inner ring at the junction of the top surface of cylinder 11 and the bottom surface of cylinder 2. The inner diameter of cylinder port 16 is larger than the outer diameter of piston rod 23 and piston rod 24 at the junction with it, and the inner diameter of cylinder port 16 is smaller than the outer diameter of piston 21 and piston retaining ring 25.

[0031] The inner ring of the top of the second cylinder 12 is fixed with a cylinder port lock nut 18 and a second cylinder port 17 from top to bottom, and a locking flange 19 is fixedly connected to the outer ring of the top of the second cylinder 12.

[0032] In this embodiment, the inner ring of the bottom of the second cylinder 12 is provided with a groove, and the outer ring of the middle part of the first cylinder port 16 is provided with a convex ring. The first cylinder port 16 is fixedly connected to the inner ring at the junction of the first cylinder 11 and the second cylinder 12 by the cooperation of the convex ring and the groove of the second cylinder 12.

[0033] The inner top ring of the cylinder barrel 12 has a groove, and the outer top ring of the cylinder port 17 has a protruding ring. The protruding ring and the groove cooperate to engage the cylinder port 17 in the inner top ring of the cylinder barrel 12. The cylinder port lock nut 18 is fixedly connected to the groove by threads and abuts against the top of the cylinder port 17 to fix it.

[0034] In this embodiment, the cylinder assembly is fixed to the beam of the hydraulic press using fixing flange 13, fixing flange 2 14, and locking flange 19. Each of the fixing flanges 13, 14, and 19 has a plurality of threaded holes evenly distributed on its inner ring. The locking flange 19, fixing flange 13, and fixing flange 2 14 are respectively fixed to the outer rings of the top, bottom, and top of cylinder barrel 2 12 and cylinder barrel 11 via the threads on their inner rings. Then, fixing flange 13 and fixing flange 2 14 are fixed together to the bolt holes on the hydraulic press beam using a plurality of bolts, and locking flange 19 is fixedly connected to bolt hole 2 on the hydraulic press beam using a plurality of bolts. Bolt holes 1 and 2 on the hydraulic press beam are conventional features and will not be described further here.

[0035] Example 3, as shown in the accompanying drawings. Figures 2-3 As shown, the bottom surface of the cylinder barrel 11 is connected to the cylinder bottom 15. The lower part of the cylinder bottom 15 is a cylinder and the upper part is a ring. The connection between the cylinder and the ring is an arc shape. The top surface of the cylinder bottom 15 is in contact with the bottom surface of the piston 21.

[0036] In this embodiment, the cylinder bottom 15 is fixedly connected to the cylinder barrel 11 by welding. The junction of the cylinder bottom 15 cylinder and the ring is arc-shaped. The advantage of this design is:

[0037] 1. Reduce stress concentration, improve the fatigue resistance of the cylinder bottom, extend the service life of the hydraulic cylinder, reduce the risk of crack propagation caused by stress concentration, and enhance safety. Right-angle or sharp-angle transitions can lead to local stress concentration (according to Saint-Venant's principle and stress concentration factor theory in elasticity), which can easily form crack initiation points under high pressure or alternating loads. Circular transitions disperse stress through a smooth geometric shape, reducing the stress concentration factor (e.g., the larger the radius of the arc, the smaller the stress concentration factor).

[0038] 2. Improve welding quality, enhance weld strength and quality consistency, and reduce early failures caused by welding defects. Using an arc-shaped transition during welding (the circumferential weld between cylinder bottom 15 and cylinder barrel 11) can provide more uniform penetration and heat distribution, avoiding incomplete fusion or stress concentration of residual weld at right angles.

[0039] Example 4, as shown in the accompanying drawings. Figures 1-2 As shown, the bottom of cylinder 11 is provided with an oil port A, and the bottom of cylinder 212 is provided with an oil port B and the top is provided with an oil port C.

[0040] Since the inner diameter of cylinder port 16 is smaller than the outer diameter of piston 21 and piston retaining ring 25, piston 21 can only slide between cylinder port 16 and cylinder bottom 15, and piston 22 and piston retaining ring 25 can only slide between cylinder port 27 and cylinder port 16.

[0041] The ejection process of this utility model is as follows:

[0042] D1. Initial position of the piston assembly is as follows: Figure 2 As shown, at this time, oil enters through port A and exits through ports B and C. The bottom outer ring of piston 21 is also provided with a groove 3. When the oil enters the plug cavity of cylinder 11 and applies a large pressure, the groove 3 is subjected to an upward pressure, which pushes piston 21 to move upward until piston 21, piston 22, piston rod 23, piston rod 24 and piston retaining ring 25 are pushed upward until piston 21 contacts cylinder port 16, completing the first stage of the push-out action.

[0043] D2. Oil enters through port B and exits through ports A and C. The oil enters the plug chambers of cylinder 11 and cylinder 212 and applies greater pressure, pushing piston 121 downward to contact the cylinder bottom 16. Piston 22 and piston retaining ring 25 drive piston rod 24 and piston rod 23 upward to contact cylinder 22 with cylinder port 27, completing the ejection action of the second stroke.

[0044] The return operation process of this utility model is as follows:

[0045] T1, oil inlets A and C, oil outlet B. Oil enters the cylinder 11 plug chamber from oil inlet A and applies a large pressure, pushing piston 21 upward to contact cylinder 16. The outer ring of piston 22 is also provided with a groove 4. Oil enters the cylinder 12 plug chamber from oil inlet C and applies a large pressure. The groove 4 is subjected to a downward pressure, pushing piston 22 to drive piston fixing ring 25, piston rod 24 and piston rod 23 downward until piston rod 23 contacts piston 21, completing the second stroke retraction action.

[0046] T2. Oil continues to enter through port C, while oil exits through ports A and B. The oil enters the plug chamber of cylinder 12 through the gap between cylinder port 16 and piston rod 23 and applies greater pressure, pushing the entire piston assembly downwards until it contacts the bottom of the cylinder 16, completing the retraction action of the first stroke.

[0047] In this embodiment, by increasing the number of cylinders, pistons and piston rods, oil ports, etc., as needed, more segments of the ejection and retraction actions can be completed by a single hydraulic cylinder.

[0048] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A multi-stroke hydraulic cylinder, characterized by: The application relates to a cylinder-piston assembly, which comprises a cylinder assembly and a piston assembly, the piston assembly is slidably arranged in the cylinder assembly, the cylinder assembly comprises a cylinder one (11) and a cylinder two (12) arranged above the cylinder one (11), the piston assembly comprises a piston one (21), a piston two (22), a piston rod one (23), a piston rod two (24) and a piston fixing ring (25), the piston one (21), the piston rod one (23) and the piston rod two (24) are sequentially arranged from bottom to top in the cylinder assembly, the piston one (21) and the piston rod one (23) are arranged in the cylinder one (11), and the piston two (22) and the piston rod two (24) are arranged in the cylinder two (12). The top surface of the piston one (21) is in contact with the bottom surface of the piston rod one (23), and the top end of the piston rod one (23) is fixedly connected with the bottom end of the piston rod two (24) through threads. The bottom outer circle of the piston rod two (24) is sequentially fixedly connected with the piston fixing ring (25) and the piston two (22) from bottom to top.

2. A multi-stroke hydraulic cylinder according to claim 1, characterized in that: The top surface of the cylinder one (11) is in contact with the bottom surface of the cylinder two (12) and is fixedly connected through a fixed flange one (13) arranged at the top outer circle of the cylinder one (11) and a fixed flange two (14) arranged at the bottom outer circle of the cylinder two (12).

3. A multi-stroke hydraulic cylinder according to claim 2, characterized in that: The cylinder one (11) is provided with an oil port A at the bottom, the cylinder two (12) is provided with an oil port B at the bottom and an oil port C at the top.

4. A multi-stroke hydraulic cylinder according to claim 2, characterized in that: The inner circle of the joint between the top surface of the cylinder one (11) and the bottom surface of the cylinder two (12) is fixedly connected with a cylinder port one (16), the inner diameter of the cylinder port one (16) is larger than the outer diameters of the piston rod one (23) and the piston rod two (24) at the joint, and the inner diameter of the cylinder port one (16) is smaller than the outer diameters of the piston one (21) and the piston fixing ring (25).

5. A multi-stroke hydraulic cylinder as claimed in claim 2, characterized in that: The bottom surface of the cylinder one (11) is connected with a cylinder bottom (15), the lower part of the cylinder bottom (15) is a cylinder body, the upper part is a circular ring, the joint between the cylinder body and the circular ring is an arc, and the top surface of the cylinder body is in contact with the bottom surface of the piston one (21).

6. A multi-stroke hydraulic cylinder as claimed in claim 2, characterized in that: The inner circle of the top of the cylinder two (12) is sequentially fixedly connected with a cylinder port lock nut (18) and a cylinder port two (17) from top to bottom, and the outer circle of the top of the cylinder two (12) is fixedly connected with a locking flange (19).

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