Sealing device for hydraulic cylinder

Abstract

The utility model provides a sealing device for a hydraulic cylinder, which comprises a cylinder body, a piston rod and a cylinder cover, the lower end of the piston rod is mounted in a plug-in piston base, an H-shaped piston bush is sleeved on the outer side of the piston rod, a sealing plate is arranged below the H-shaped piston bush, a buffer mechanism is arranged at the lower end in the cylinder body, and the buffer mechanism is connected with the cylinder cover. The buffering mechanism comprises a sleeve, a movable column, a buffering plate and a spring, the movable column is sleeved with the spring, one end of the spring is fixedly connected with the buffering plate, the other end of the spring is fixedly connected with the sleeve, the sleeve is fixedly installed at the bottom of the cylinder body, the upper end of the movable column is fixedly connected with the buffering plate, and a buffering rubber layer is arranged on the upper surface of the buffering plate. A double dynamic sealing system can be constructed, and the risk of hydraulic oil leakage is remarkably reduced; the variable stiffness spring and the honeycomb damping buffer rubber layer are used for effectively absorbing impact energy of the piston rod, and vibration and noise are reduced.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, and in particular to a sealing device for hydraulic cylinders. Background Technology

[0002] Hydraulic presses, as important pressure processing equipment, are widely used in many industrial fields such as automobile manufacturing, aerospace, and hardware processing. In various processing techniques, such as sheet metal stamping and stretch forming, the hydraulic ejection mechanism plays a key role in smoothly ejecting the processed workpiece from the mold.

[0003] Existing technology discloses a hydraulic cylinder sealing device with application number 202021590434.9, comprising: a cylinder body, a piston rod movably disposed within the cylinder body, and a piston disposed on the piston rod; the piston is provided with a first sealing component suitable for sealing the interior of the cylinder body; and a second sealing component suitable for sealing the exterior of the cylinder body is provided at the connection between the cylinder body and the piston rod. This hydraulic cylinder sealing device uses the first and second sealing components to seal the interior and exterior of the hydraulic cylinder respectively, thereby reducing internal and external leakage and improving its performance and lifespan. However, existing technology still lacks an effective buffer mechanism. At the end of its stroke, the piston rod is prone to impacting the bottom of the cylinder body or the piston due to inertia, causing deformation and detachment of the seals, shortening the device's lifespan, and generating severe vibration and noise, affecting the working environment. Furthermore, traditional sealing components often use a single material or structure, such as ordinary rubber seals, which are prone to wear and aging under high pressure and high-frequency reciprocating motion conditions, leading to internal or external leakage of hydraulic oil, affecting equipment operating efficiency and processing accuracy, and even causing safety hazards. Therefore, we propose a sealing device for hydraulic cylinders to solve the above problems. Utility Model Content

[0004] To address the shortcomings mentioned above, this utility model provides a sealing device for hydraulic cylinders, which can construct a dual dynamic sealing system through the line contact seal of the H-type piston sleeve and the composite material sealing plate, significantly reducing the risk of hydraulic oil leakage; and utilizes a variable stiffness spring and a honeycomb damping buffer rubber layer to effectively absorb the impact energy of the piston rod, reducing vibration and noise.

[0005] To solve the above problems, the technical solution provided by this utility model is as follows:

[0006] A sealing device for a hydraulic cylinder includes a cylinder body, a piston rod, and a cylinder head. The cylinder body has a threaded connection at its top, and the cylinder head has an internal thread adapted to the threaded connection. The piston rod passes through the cylinder head and extends into the cylinder body. A plug-in piston base is provided inside the cylinder body. The lower end of the piston rod is installed inside the plug-in piston base. An H-shaped piston sleeve is fitted on the outer side of the piston rod. A sealing plate is provided below the H-shaped piston sleeve. A buffer mechanism is provided at the lower end of the cylinder body. The buffer mechanism includes a sleeve, a movable column, a buffer plate, and a spring. The spring is sleeved on the outer side of the movable column. One end of the spring is fixedly connected to the buffer plate, and the other end of the spring is fixedly connected to the sleeve. The sleeve is fixedly installed at the bottom of the cylinder body. The upper end of the movable column is fixedly connected to the buffer plate, and a buffer rubber layer is provided on the upper surface of the buffer plate.

[0007] Furthermore, the H-shaped piston sleeve is integrally molded from a high-elasticity polyurethane material. The waist of the H-shaped piston sleeve has an inwardly concave arc structure. The inner wall of the H-shaped piston sleeve is interference-fitted with the piston rod, and the outer wall of the H-shaped piston sleeve forms a line contact seal with the inner wall of the cylinder.

[0008] Furthermore, a limiting block is fixedly provided on the piston rod, and the limiting block is located on the outside of the cylinder head.

[0009] Furthermore, a sealing gasket is provided between the cylinder head and the cylinder block.

[0010] Furthermore, the sealing plate adopts a composite design of an elastic metal skeleton and polytetrafluoroethylene.

[0011] Furthermore, the surface of the buffer rubber layer is provided with honeycomb-shaped grooves, and the interior of the honeycomb-shaped grooves is filled with damping material.

[0012] Furthermore, the spring is a variable stiffness helical structure.

[0013] Furthermore, a first connecting ring plate is fixedly installed on the outer side of the cylinder body, and a second connecting ring plate is fixedly installed on the lower outer side of the cylinder head. The first connecting ring plate and the second connecting ring plate are fixedly connected by bolts.

[0014] Furthermore, the surface of the bolt is treated with Dacromet coating.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The H-type piston sleeve is made of high-elasticity polyurethane material. It forms a line contact seal with the inner wall of the cylinder through the waist arc structure. Combined with the interference fit between its inner wall and the piston rod, it significantly improves the sealing accuracy. The sealing plate below adopts a composite design of elastic metal skeleton and polytetrafluoroethylene. It can adaptively adjust the sealing tightness according to the hydraulic pressure. The dual sealing system effectively reduces the risk of internal and external leakage and is suitable for high-pressure and high-frequency reciprocating motion conditions.

[0017] 2. The variable stiffness helical spring in the buffer mechanism can provide a gradual buffering force at the end of the piston rod movement. It gently absorbs the impact in the early stage and enhances the rigidity in the later stage to avoid rigid collisions. The honeycomb grooves on the surface of the buffer rubber layer are filled with damping material, which can absorb energy through structural deformation, suppress vibration transmission, reduce noise, extend the service life of seals and cylinder, and improve the stability of equipment operation.

[0018] 3. The cylinder block and cylinder head are fastened with high-strength anti-loosening bolts through the connection ring plate one and two. The bolt surface has a Dacromet coating with excellent anti-corrosion performance, and the connection surface is precisely ground to ensure that the sealing gasket is under uniform pressure. The rigid connection design of the plug-in piston base and piston rod improves the reliability of torque transmission. The overall structure can remain stable in harsh environments such as high pressure and corrosion, reducing the frequency of maintenance and extending the service life of the equipment.

[0019] In summary, this sealing device for hydraulic cylinders has wide applicability, addressing the shortcomings of existing technologies mentioned in the background section, such as the lack of an effective buffer mechanism, the piston rod's tendency to impact the cylinder bottom or piston at the end of its stroke due to inertia, causing deformation and detachment of the seals, shortening the device's service life, and generating severe vibration and noise, affecting the working environment. Furthermore, traditional sealing components often use a single material or structure, such as ordinary rubber seals, which are prone to wear and aging under high pressure and high-frequency reciprocating motion conditions, leading to internal or external leakage of hydraulic oil, affecting equipment operating efficiency and processing accuracy, and even causing safety hazards. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of this utility model.

[0021] Explanation of key component symbols:

[0022] 1-Cylinder body, 101-Threaded connection, 102-Connecting ring plate one, 2-Piston rod, 3-Cylinder head, 301-Connecting ring plate two, 4-Sealing gasket, 5-Plug-in piston base, 6-Sleeve, 7-Moving column, 8-Buffer plate, 801-Buffer rubber layer, 9-Spring, 10-H-type piston sleeve, 11-Sealing plate, 12-Limiting block, 13-Bolt. Detailed Implementation

[0023] To make the objectives, technical solutions and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and examples, but the examples given are not intended to limit the present utility model.

[0024] like Figure 1 As shown, the embodiment of this utility model includes a cylinder body 1, a piston rod 2, and a cylinder head 3.

[0025] The cylinder body 1 has a threaded connection part 101 at the top, and the cylinder head 3 has a matching internal thread. At the same time, the connecting ring plate 102 on the outer side of the cylinder body 1 and the connecting ring plate 301 on the lower outer side of the cylinder head 3 are fixedly connected by bolts 13 with Dacromet coating. A sealing gasket 4 is provided between the cylinder head 3 and the cylinder body 1. The dual connection method (threaded connection and bolt connection) ensures that the cylinder body and the cylinder head are firmly connected. The Dacromet coated bolts have excellent corrosion resistance and extend service life. The sealing gasket 4 effectively prevents external impurities from entering the cylinder body and internal hydraulic oil leakage, thus improving sealing performance.

[0026] The piston rod 2 passes through the cylinder head 3 and extends into the cylinder body 1, with its lower end installed in the insert piston base 5. An H-shaped piston sleeve 10, integrally molded from high-elasticity polyurethane material, is fitted on the outer side. The waist of the H-shaped piston sleeve 10 has an inwardly concave arc structure. The inner wall is interference-fitted with the piston rod 2, and the outer wall forms a line contact seal with the inner wall of the cylinder body 1. A limit block 12 is fixedly installed on the piston rod 2, located on the outer side of the cylinder head 3. The H-shaped piston sleeve 10 made of high-elasticity polyurethane material has good wear resistance and sealing performance. The interference fit and line contact seal design can effectively prevent hydraulic oil leakage and improve the working efficiency of the hydraulic cylinder. The limit block 12 can limit the stroke of the piston rod 2 and prevent it from excessively moving and causing damage to the components.

[0027] Below the H-type piston sleeve 10 is a sealing plate 11 with a composite design of an elastic metal skeleton and polytetrafluoroethylene (PTFE). The elastic metal skeleton provides support strength, while PTFE has an extremely low coefficient of friction and good chemical stability. The combination of the two ensures that the sealing plate 11 can not only guarantee the sealing effect but also reduce frictional resistance, reduce wear, and extend the service life of the sealing device.

[0028] A buffer mechanism is installed at the lower end of the cylinder body 1, including a sleeve 6, a movable column 7, a buffer plate 8, and a spring 9. The spring 9 is a variable stiffness helical structure, sleeved on the outside of the movable column 7, with one end fixedly connected to the buffer plate 8 and the other end fixedly connected to the sleeve 6. The sleeve 6 is fixedly installed at the bottom of the cylinder body 1, and the upper end of the movable column 7 is fixedly connected to the buffer plate 8. The upper surface of the buffer plate 8 is provided with a buffer rubber layer 80, which has honeycomb-shaped grooves and is filled with damping material. The variable stiffness helical spring 9 can automatically adjust the buffering force according to the impact force of the piston rod, improving the buffering effect. The buffer rubber layer 801, in conjunction with the damping material, can effectively absorb and dissipate the impact force generated by the piston rod movement, reducing vibration and noise, protecting the internal structure of the hydraulic cylinder, and extending the overall service life of the hydraulic cylinder.

[0029] All electrical components mentioned in the text are electrically connected to an external controller and power supply, and the controller can be a conventional known device such as a computer that provides control.

[0030] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sealing device for a hydraulic cylinder, comprising a cylinder body (1), a piston rod (2), and a cylinder head (3), wherein the top of the cylinder body (1) is provided with a threaded connection portion (101), the cylinder head (3) is provided with an internal thread adapted to the threaded connection portion (101), and the piston rod (2) extends through the cylinder head (3) into the interior of the cylinder body (1), characterized in that, The cylinder body (1) is provided with a plug-in piston base (5). The lower end of the piston rod (2) is installed in the plug-in piston base (5). An H-shaped piston sleeve (10) is sleeved on the outside of the piston rod (2). A sealing plate (11) is provided below the H-shaped piston sleeve (10). A buffer mechanism is provided at the lower end of the cylinder body (1). The buffer mechanism includes a sleeve (6), a movable column (7), a buffer plate (8), and a spring (9). The spring (9) is sleeved on the outside of the movable column (7). One end of the spring (9) is fixedly connected to the buffer plate (8). The other end of the spring (9) is fixedly connected to the sleeve (6). The sleeve (6) is fixedly installed at the bottom of the cylinder body (1). The upper end of the movable column (7) is fixedly connected to the buffer plate (8). A buffer rubber layer (801) is provided on the upper surface of the buffer plate (8).

2. A sealing device for a hydraulic cylinder as described in claim 1, characterized in that, The H-shaped piston sleeve (10) is integrally molded from high-elasticity polyurethane material. The waist of the H-shaped piston sleeve (10) has an inwardly concave arc structure. The inner wall of the H-shaped piston sleeve (10) is interference-fitted with the piston rod (2). The outer wall of the H-shaped piston sleeve (10) forms a line contact seal with the inner wall of the cylinder (1).

3. A sealing device for a hydraulic cylinder as described in claim 2, characterized in that, A limiting block (12) is fixedly provided on the piston rod (2), and the limiting block (12) is located on the outside of the cylinder head (3).

4. A sealing device for a hydraulic cylinder as described in claim 3, characterized in that, A sealing gasket (4) is provided between the cylinder head (3) and the cylinder body (1).

5. A sealing device for a hydraulic cylinder as described in claim 4, characterized in that, The sealing plate (11) adopts a composite design of elastic metal skeleton and polytetrafluoroethylene.

6. A sealing device for a hydraulic cylinder as described in claim 5, characterized in that, The surface of the buffer rubber layer (801) is provided with honeycomb-shaped grooves, and the interior of the honeycomb-shaped grooves is filled with damping material.

7. A sealing device for a hydraulic cylinder as described in claim 6, characterized in that, The spring (9) is a variable stiffness helical structure.

8. A sealing device for a hydraulic cylinder as described in claim 7, characterized in that, A connecting ring plate one (102) is fixedly installed on the outer side of the cylinder body (1), and a connecting ring plate two (301) is fixedly installed on the lower outer side of the cylinder head (3). The connecting ring plate one (102) and the connecting ring plate two (301) are fixedly connected by bolts (13).

9. A sealing device for a hydraulic cylinder as described in claim 8, characterized in that, The surface of the bolt (13) is treated with Dacromet coating.

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