Improved hydraulic cylinder piston dismounting device

Abstract

The utility model relates to hydraulic oil cylinder maintenance technical field especially discloses a kind of dismounting device of improved hydraulic oil cylinder piston, to solve the problem of traditional hydraulic oil cylinder piston dismounting time-consuming and labor-consuming, easily damaged component and unsafe. The dismounting mode is based on the device of pressure gauge, pressure gauge flange, pressure gauge short pipe, piston ring, hydraulic cylinder body, piston, guide rod, inlet and outlet pipe flange, valve, inlet and outlet oil pipe flange, piston rod, sling, hydraulic oil cylinder end cover composition is realized;When operating, first, the oil cylinder is operated to the piston end cover, discharges hydraulic oil after dismounting relevant flange and screw rod, then installs guide rod, pressure gauge assembly, valve and sling, and the piston is removed along guide rod by nitrogen gas. The mode is safe and reliable, reduces labor intensity, reduces pollution, improves maintenance efficiency.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder repair technology, and in particular to an improved hydraulic cylinder piston disassembly device. Background Technology

[0002] A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy to achieve linear reciprocating motion (or oscillating motion). It has a simple structure, reliable operation, and requires no speed reduction device or transmission backlash during reciprocating motion, resulting in smooth operation. Therefore, it is widely used in the hydraulic systems of various types of machinery. A hydraulic cylinder mainly consists of a cylinder body, cylinder head, piston, piston rod, sealing device, buffer device, and venting device. The piston and piston rod are the core moving parts and require regular disassembly and maintenance.

[0003] The traditional method for maintenance personnel to disassemble hydraulic cylinder pistons is as follows: First, move the hydraulic cylinder to the piston end cap, remove the parts connected to the piston rod head, then loosen the inlet and outlet oil pipes and connectors, and slowly pour the hydraulic oil in the cylinder into a prepared oil container; after the hydraulic oil has been completely drained, remove the inlet and outlet oil pipes and inlet and outlet pipe flanges, and remove the fastening bolts around the hydraulic cylinder end cap; finally, install a lifting rope on the piston rod head, and have multiple people work together to pull the piston rod outward.

[0004] This traditional disassembly method has obvious drawbacks: First, the piston and piston rod are prone to collision with the cylinder or other parts during manual pulling, resulting in serious external damage. Some pistons and piston rods may even become unusable due to damage. Second, it requires multiple people to work together, which greatly increases the labor intensity of employees. Third, the maintenance process is cumbersome and time-consuming, resulting in low maintenance efficiency and increasing maintenance costs and spare parts replacement costs. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides an improved hydraulic cylinder piston disassembly device, which solves the technical problems of traditional hydraulic cylinder piston disassembly being time-consuming, labor-intensive, and unsafe (easily causing external damage to the piston and piston rod, high labor intensity for employees, long maintenance time, and high maintenance and spare parts costs).

[0006] To achieve the above objectives, this utility model provides the following technical solution: An improved hydraulic cylinder piston disassembly device includes a hydraulic cylinder body, piston, piston rod, hydraulic cylinder end cap, guide rod, pressure gauge, pressure gauge flange, pressure gauge short tube, inlet / outlet flange one, valve, inlet / outlet flange two, and lifting rope; The piston is located inside the hydraulic cylinder body, one end of the piston rod is fixedly connected to the piston, and the hydraulic cylinder end cover is fitted onto the end of the hydraulic cylinder body and is used to seal the hydraulic cylinder body. The pressure gauge is connected to the pressure gauge short pipe via the pressure gauge flange, and the end of the pressure gauge short pipe away from the pressure gauge flange is installed on the hydraulic cylinder body. Inlet / outlet flange one and inlet / outlet flange two are respectively fixed to two oil inlets on the side wall of the hydraulic cylinder body. One end of the valve is connected to inlet / outlet flange one, and the other end of the valve is connected to a nitrogen source through a high-pressure hose.

[0007] Preferably, one end of the guide rod is machined with an external thread, and the threaded end is screwed into the pre-set threaded hole on the top of the hydraulic cylinder end cover. The guide rod is made of 45 steel and the outer peripheral wall of the guide rod is coated with a zinc-aluminum alloy anti-rust coating.

[0008] Preferably, the suspension rope is detachably connected to the head of the piston rod away from the piston; The piston is fitted with piston rings on its outer peripheral wall. The pressure gauge is a radially mounted shock-resistant pressure gauge with a range of 0-1.6 MPa and an accuracy class of not less than 0.4.

[0009] Preferably, the valve is a J11W type stainless steel manual stop valve, and the nominal diameter of the valve is compatible with the nominal diameter of the inlet and outlet flanges.

[0010] Preferably, the hoisting rope is a high-strength polypropylene hoisting rope with a breaking strength of not less than 50kN, and the middle of the hoisting rope is provided with a wear-resistant rubber sleeve for mounting the piston rod.

[0011] Preferably, the axial length of the guide rod is 150-200mm longer than that of the hydraulic cylinder body, and the end of the guide rod away from the hydraulic cylinder end cover is integrally formed with a cylindrical anti-slip handle, and the outer circumference of the handle is provided with knurled texture.

[0012] Preferably, both ends of the pressure gauge short tube are threaded. One end is screwed into the internal threaded hole of the pressure gauge flange, and the other end is screwed into the pre-set threaded interface on the hydraulic cylinder body. The gaps between the two threaded connections are filled with polytetrafluoroethylene sealing tape. The rubber sealing gasket between the inlet / outlet flange and the hydraulic cylinder oil port is made of nitrile rubber with a thickness of 3mm. The gasket has positioning holes that correspond one-to-one with the flange bolt holes.

[0013] Compared with the prior art, the present invention has the following beneficial effects: This invention, by setting a guide rod, can limit the falling trajectory of the piston during the removal process, avoiding damage caused by the piston falling due to its own weight; at the same time, by monitoring the cylinder pressure in real time with a pressure gauge, it can accurately control the nitrogen gas injection pressure, preventing excessive pressure from damaging the hydraulic cylinder body, thus solving the problems of easy damage to parts and unsafe operation in traditional disassembly methods.

[0014] Traditional disassembly requires multiple people to pull the piston rod together. However, this invention connects to a nitrogen source through a valve, using nitrogen pressure to push the piston and piston rod outward. Disassembly can be completed by only one operator controlling the valve opening and using a lifting rope for assistance, which greatly reduces the physical exertion of maintenance personnel.

[0015] Before disassembly, by loosening the joints between the inlet and outlet oil pipes and the inlet and outlet oil pipe flanges, the hydraulic oil in the hydraulic cylinder is concentrated and guided into a sealed oil tank. This avoids the environmental oil pollution problem caused by the random dripping of hydraulic oil during traditional disassembly, and realizes the recycling or standardized treatment of hydraulic oil.

[0016] Compared to traditional disassembly methods that involve multiple people pulling and the risk of parts being damaged and requiring rework, this invention uses nitrogen to propel the piston out smoothly and quickly with the help of a guide rod. This eliminates the need for subsequent repairs of damaged parts, shortens the entire disassembly process compared to traditional methods, and reduces maintenance costs and spare parts replacement costs.

[0017] All components used in the device are common and readily available, making assembly and disassembly simple and requiring no complex debugging. Furthermore, the components are tightly connected, ensuring a stable disassembly process, making it suitable for piston disassembly scenarios of hydraulic cylinders of different specifications. Attached Figure Description

[0018] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Legend: 1. Pressure gauge; 2. Pressure gauge flange; 3. Pressure gauge short pipe; 4. Piston ring; 5. Hydraulic cylinder body; 6. Piston; 7. Guide rod; 8. Inlet / outlet flange one; 9. Valve; 10. Inlet / outlet flange two; 11. Piston rod; 12. Lifting rope; 13. Hydraulic cylinder end cap. Detailed Implementation

[0021] This application provides an improved hydraulic cylinder piston disassembly device, which effectively solves the technical problems of traditional hydraulic cylinder piston disassembly being time-consuming, labor-intensive, and unsafe (easily causing external damage to the piston and piston rod, high labor intensity for employees, long maintenance time, and high maintenance and spare parts costs). Example

[0022] like Figure 1 As shown, the overall technical solution in this application embodiment is as follows: To address the problems existing in the prior art, this utility model provides an improved hydraulic cylinder piston disassembly device. Based on a disassembly mechanism consisting of a pressure gauge 1, pressure gauge flange 2, pressure gauge short pipe 3, piston ring 4, hydraulic cylinder body 5, piston 6, guide rod 7, inlet / outlet pipe flange 18, valve 9, inlet / outlet oil pipe flange 210, piston rod 11, lifting rope 12, and hydraulic cylinder end cap 13, its core functionality is achieved by adding a guide and limiting structure, a pressure monitoring structure, and a nitrogen-driven structure, thus solving the problems of easy piston damage and high labor intensity in traditional disassembly methods. Detailed explanations of the specific operating steps and structural functions are as follows: Preliminary preparations and initial state adjustments: First, adjust the hydraulic cylinder to be repaired so that the piston 6 is close to the hydraulic cylinder end cover 13, ensuring a small gap between the piston 6 and the hydraulic cylinder end cover 13. This prevents excessive stroke when the piston 6 is moved out later due to an initial position that is too far away. Then, use tools such as socket wrenches and Allen wrenches to remove all auxiliary components connected to the head of the piston rod 11, including but not limited to the positioning nut, connecting flange, dust cover, etc., to ensure that the head of the piston rod 11 is unobstructed, leaving operating space for the subsequent installation of the lifting rope 12 and the removal of the piston 6. At the same time, check whether there is oil or rust on the surface of the piston rod 11. If so, wipe it clean with a clean cloth to prevent impurities from affecting disassembly during subsequent operations.

[0023] Hydraulic oil draining and flange removal: First, use an adjustable wrench to slowly loosen the connection between the inlet / outlet oil pipe and the inlet / outlet oil pipe flange 210. Place a pre-prepared sealed oil tank (the capacity must be larger than the internal volume of the hydraulic cylinder 5) under the connection. Slowly guide the hydraulic oil inside the hydraulic cylinder 5 into the oil tank through the connection. The flow rate must be controlled throughout the discharge process to avoid hydraulic oil splashing and polluting the environment. At the same time, observe the oil level in the oil tank to prevent overflow. The second step is to completely drain the hydraulic oil from the hydraulic cylinder body 5 (this can be observed through the interface of the inlet and outlet oil pipe flange 210; if no oil droplets flow out, it means the cylinder has been emptied). Use a torque wrench to completely remove the inlet and outlet oil pipes, then unscrew all the fixing bolts connecting the inlet and outlet oil pipe flange 210 to the hydraulic cylinder body 5, remove the inlet and outlet oil pipe flange 210 and store it properly. Third, using the same torque wrench, unscrew the circumferentially distributed fastening screws between the hydraulic cylinder body 5 and the hydraulic cylinder end cover 13 one by one, so that the hydraulic cylinder end cover 13 is separated from the hydraulic cylinder body 5, but do not remove the hydraulic cylinder end cover 13 for the time being, so as to provide a reference for the subsequent installation of the guide rod 7.

[0024] Guide rod 7 installation: A guide rod 7 with an axial length longer than that of the hydraulic cylinder body 5 is selected (the length must ensure that the piston 6 can still slide along the guide rod 7 when it is fully moved out, to avoid detachment). One end of the guide rod 7 is pre-machined with an external thread that matches the threaded hole of the hydraulic cylinder end cover 13. Align the threaded end of the guide rod 7 with the pre-set threaded hole at the top of the hydraulic cylinder end cover 13, and slowly screw it in by hand until it cannot be turned, then tighten it clockwise with a wrench to ensure that the guide rod 7 is firmly connected to the hydraulic cylinder end cover 13 without loosening. The function of the guide rod 7 is to provide a fixed trajectory for the movement of the piston 6 and piston rod 11, limit their radial displacement, and prevent the piston 6 from falling due to its own weight during the movement process, which would cause the piston 6 and piston rod 11 to collide with the inner wall of the hydraulic cylinder body 5, resulting in scratches or deformation.

[0025] Pressure gauge assembly and inlet / outlet flange 18 installation: First, at the pressure monitoring interface pre-set on the side wall of the hydraulic cylinder body 5 (usually located on the upper part of the cylinder body, near the hydraulic cylinder end cover 13), screw one end of the pressure gauge short tube 3 into the interface, and seal the threads with Teflon tape (5-8 layers to ensure no leakage). Then, put the pressure gauge flange 2 on the other end of the pressure gauge short tube 3 and fix the flange with bolts. Finally, install the pressure gauge 1 on the pressure gauge flange 2 and tighten the fixing nut to ensure that the pressure gauge 1 and the flange are sealed and fitted. The internal pressure of the hydraulic cylinder body 5 can be monitored in real time through the pressure gauge 1 to prevent the cylinder body from being damaged by excessive pressure. The second step is to fix the inlet / outlet flange 18 to the nitrogen inlet port on the other side wall of the hydraulic cylinder 5 with bolts. Place a nitrile rubber sealing gasket between the flange and the cylinder. When tightening the bolts, use the diagonal tightening method to avoid uneven force on the flange and leakage. The function of the inlet / outlet flange 18 is to provide a connection reference for nitrogen inlet.

[0026] Installation of hoisting rope 12 and valve 9: The first step is to fix one end of the lifting rope 12 to the head of the piston rod 11 away from the piston 6 using a U-shaped buckle. The buckle needs to be tightly locked in the annular groove of the piston rod 11 to ensure that the lifting rope 12 is reliably connected to the piston rod 11. The other end of the lifting rope 12 can be connected to a crane or manual hoist to assist in lifting the piston rod 11 and reduce the load when nitrogen is pushed. The second step is to connect one end of valve 9 to the inlet / outlet flange 18 with bolts. A sealing gasket is also placed between valve 9 and the flange. The other end is connected to the nitrogen source through a high-pressure hose. The function of valve 9 is to control the entry and exit of nitrogen. By adjusting the opening of valve 9, the flow rate of nitrogen can be controlled, thereby controlling the exit speed of piston 6.

[0027] Piston 6 has been removed and disassembled. The first step is to conduct a comprehensive inspection after all installations are completed: check whether the guide rod 7 is secure, whether the pressure gauge 1 is zero, whether the valve 9 is closed, whether the lifting rope 12 is tightened, and whether all flange connections are sealed. After confirming that there are no omissions or looseness, proceed with the subsequent operations. The second step is to slowly rotate the handwheel of valve 9 to open valve 9, allowing nitrogen to enter the hydraulic cylinder 5 smoothly. Observe the reading of pressure gauge 1 to ensure that the pressure rises slowly. Under the action of nitrogen pressure, piston 6 drives piston rod 11 to move outward along the axis of hydraulic cylinder 5. At this time, the piston rod 11 can be pulled upward with the help of the hoisting rope 12 to keep the piston rod 11 parallel to the guide rod 7. Third step: When piston 6 moves to a position close to hydraulic cylinder end cover 13, slowly close valve 9 to stop nitrogen gas supply. At this time, piston ring 4 fitted on the outer peripheral wall of piston 6 is still in contact with the inner wall of hydraulic cylinder 5 to prevent impurities from entering the cylinder. Fourth step, continue to pull the piston rod 11 with the hoisting rope 12, so that the piston 6 moves smoothly out of the hydraulic cylinder 5 along the extension direction of the guide rod 7 until the piston 6 is completely separated from the cylinder. Then remove the hoisting rope 12, guide rod 7, pressure gauge 1 and other components to complete the disassembly operation of the entire hydraulic cylinder piston 6.

[0028] This embodiment replaces traditional manual pulling with nitrogen propulsion. With the trajectory limit of guide rod 7 and the auxiliary lifting of rope 12, it not only avoids external damage to piston 6 and piston rod 11, but also reduces the labor intensity of maintenance personnel (no need for multiple people to pull together). At the same time, the centralized recycling of hydraulic oil reduces environmental pollution. The entire disassembly process takes less time than the traditional method, and the maintenance efficiency is significantly improved.

[0029] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. An improved hydraulic cylinder piston disassembly device, characterized in that, Includes hydraulic cylinder body (5), piston (6), piston rod (11), hydraulic cylinder end cover (13), guide rod (7), pressure gauge (1), pressure gauge flange (2), pressure gauge short pipe (3), inlet and outlet pipe flange one (8), valve (9), inlet and outlet pipe flange two (10) and lifting rope (12); The piston (6) is located inside the hydraulic cylinder body (5), and one end of the piston rod (11) is fixedly connected to the piston (6). The hydraulic cylinder end cap (13) covers the end of the hydraulic cylinder body (5) and is used to seal the hydraulic cylinder body (5). The pressure gauge (1) is connected to the pressure gauge short tube (3) through the pressure gauge flange (2), and the end of the pressure gauge short tube (3) away from the pressure gauge flange (2) is installed on the hydraulic cylinder body (5); Inlet and outlet flange 1 (8) and inlet and outlet flange 2 (10) are respectively fixed at two oil inlets on the side wall of the hydraulic cylinder body (5). One end of valve (9) is connected to inlet and outlet flange 1 (8), and the other end of valve (9) is connected to nitrogen source through high pressure hose.

2. The improved hydraulic cylinder piston disassembly device according to claim 1, characterized in that, One end of the guide rod (7) is machined with an external thread, and the threaded end is screwed into the pre-set threaded hole on the top of the hydraulic cylinder end cap (13).

3. The improved hydraulic cylinder piston disassembly device according to claim 2, characterized in that, The suspension rope (12) is detachably connected to the head of the piston rod (11) away from the piston (6); A piston ring (4) is fitted on the outer peripheral wall of the piston (6), and the pressure gauge (1) is a radially mounted shock-resistant pressure gauge.

4. The improved hydraulic cylinder piston disassembly device according to claim 3, characterized in that, The nominal diameter of the valve (9) is compatible with the nominal diameter of the inlet / outlet flange (8).

5. The improved hydraulic cylinder piston disassembly device according to claim 4, characterized in that, The middle of the suspension rope (12) is provided with a wear-resistant rubber sleeve for mounting the piston rod (11).

6. The improved hydraulic cylinder piston disassembly device according to claim 5, characterized in that, The end of the guide rod (7) away from the hydraulic cylinder end cap (13) is integrally formed with a cylindrical anti-slip handle, and the outer periphery of the handle is provided with knurled texture.

7. The improved hydraulic cylinder piston disassembly device according to claim 6, characterized in that, Both ends of the pressure gauge short tube (3) are machined with pipe threads. One end is screwed into the internal thread hole of the pressure gauge flange (2), and the other end is screwed into the threaded interface on the hydraulic cylinder body (5). The gaps of the two threaded connections are filled with polytetrafluoroethylene sealing tape.

8. The improved hydraulic cylinder piston disassembly device according to claim 7, characterized in that, The rubber sealing gasket between the inlet / outlet flange 2 (10) and the oil passage of the hydraulic cylinder body (5) is made of nitrile rubber, and the gasket is provided with positioning holes that correspond one-to-one with the flange bolt holes.

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