Flange cylinder bottom connecting structure of hydraulic cylinder

Abstract

The utility model provides a hydraulic cylinder flange cylinder bottom connecting structure. A hydraulic cylinder flange and cylinder bottom connecting structure comprises a cylinder barrel, a flange, a clamping key, a cylinder bottom, an inner hexagon screw and a sealing ring. The flange is sleeved on the positioning step, the positioning step is arranged on the outer side of a cylinder barrel of the hydraulic oil cylinder in a surrounding mode, an outer ring groove is formed in the positioning step in a surrounding mode, a limiting body is arranged in the outer ring groove, a limiting step is arranged on the inner side of the flange in a surrounding mode, the limiting body is arranged on the right side of the flange, a groove is formed in the outer side of the cylinder bottom, a sealing piece is arranged in the groove, and the flange is fixed on the cylinder barrel through screws on the outer side of the cylinder bottom. According to the hydraulic cylinder flange and cylinder bottom connecting structure, through the design of the flange and the limiting body, on the premise that the diameter of the front end of the cylinder barrel does not need to be increased, the cylinder barrel and the flange are easy to machine, the assembling efficiency is high, and installation is easy.

Description

Technical Field

[0001] The utility model relates to the field of oil cylinders, in particular to a hydraulic cylinder flange bottom connection structure. Background Art

[0002] Common connection methods between the existing hydraulic cylinder barrel and flange, and between the cylinder barrel and the cylinder bottom generally include tie rod connection, external key connection, flange connection, elastic retaining ring connection, welding connection and threaded connection.

[0003] The tie rod type has a simple structure, good processability, and convenient cylinder processing, but the end cover is heavy and large in size, and the tie rod will stretch and deform when subjected to force, affecting the sealing effect.

[0004] The welding type welds the end cover directly to the cylinder barrel. It has high strength and is simple to manufacture, but it is easy to cause welding deformation. The material properties in the area affected by welding heat are reduced. Therefore, the weld should not be less than 20 mm from the working surface of the cylinder inner wall. In addition, the cylinder head needs to be destroyed during welding maintenance.

[0005] Elastic retaining ring type, there are two types of elastic retaining ring and steel wire elastic retaining ring. Since they are all standard parts, they are easy to use. However, the bearing capacity of this connection is not strong, and it is not convenient to disassemble and assemble, especially the cylinder wire, which must be equipped with special tools.

[0006] The cylinder barrel and flange, cylinder barrel and cylinder bottom are connected by welding, which is not convenient for processing. The high heat generated during welding will cause the inner hole of the cylinder barrel to deform. When flange welding is used for connection, it is generally necessary to temper and eliminate welding stress before processing the inner hole of the cylinder barrel, and the processing cycle is relatively long; while the threaded connection is complicated to process, and requires high processing accuracy for the cylinder barrel and parts, and the cost is relatively high. The Chinese utility model patent with the authorization announcement number CN219570496U discloses a cylinder barrel and cylinder bottom connection structure, including a cylinder barrel and a cylinder bottom, the cylinder bottom includes a barrel body, an end cover welded to one end of the barrel body, the outer wall of the barrel body away from the end cover is provided with an external thread, the inner wall of one end of the cylinder barrel is provided with an internal thread matching the external thread, and a circle of first sealing gasket is embedded on the barrel body near the external thread. After the cylinder barrel 1 and the cylinder bottom are threadedly connected, the cylinder barrel and the cylinder bottom are further fixed by a snap-fit ​​structure. After the cylinder barrel and the cylinder bottom are threadedly connected, they are fixed by a clamping mechanism, which further ensures the stability of the connection between the cylinder barrel and the cylinder bottom. No welding is required, which is convenient for the assembly and production of the cylinder and the maintenance of the interior of the cylinder barrel.

[0007] However, the connection structures in the above patents still have the following problems: (1) After the cylinder barrel and the cylinder bottom are connected, a locking hook is needed for connection, and the connection reliability is not high and it is not convenient for disassembly; (2) The connection between the cylinder barrel and the cylinder bottom is completed by using the internal thread of the cylinder bottom and the connecting piece, and the connection is complex and inconvenient. Therefore, it has become an urgent problem to design a hydraulic cylinder flange connection structure with relatively simple processing of the flange and the cylinder barrel, easy to install and not increasing the diameter of the front end of the cylinder barrel. Summary of the Invention

[0008] The problem to be solved by the present utility model is to provide a hydraulic cylinder flange cylinder bottom connection structure with relatively simple processing of the flange and the cylinder barrel and easy to install without changing the diameter of the front end of the cylinder barrel by sleeving the flange on the positioning step of the cylinder barrel and fixing it with a key.

[0009] To achieve the above object, the present utility model adopts the following technical solutions.

[0010] A flange cylinder bottom connection structure of a hydraulic cylinder, comprising a cylinder barrel, a flange, a key, a cylinder bottom, an inner hexagon screw, and a sealing ring; the flange is sleeved on the positioning step, the positioning step is surrounded outside the cylinder barrel of the hydraulic cylinder and is tightly connected to the cylinder barrel, the positioning step is surrounded by an outer ring groove, a limiting body is arranged in the outer ring groove, a limiting step is surrounded inside the flange, the limiting body is installed on the right side of the flange, a groove is arranged on the outer side of the cylinder bottom, and a sealing member is arranged in the groove, and the flange is fixed on the cylinder barrel with screws on the outer side of the cylinder bottom. This structure provides a hydraulic cylinder flange cylinder bottom connection structure with relatively simple processing of the cylinder barrel and the flange, high assembly efficiency and easy to install without increasing the diameter of the front end of the cylinder barrel through the design of the flange and the limiting body.

[0011] Preferably, the limiting body includes a key; the cross-sectional shape of the outer ring groove is rectangular; the cross-sectional shape of the limiting step is rectangular; the cross-section of the key is rectangular; the diameter of the key respectively matches the diameter of the outer ring groove and the limiting step. It is convenient to manufacture and beneficial to assembly.

[0012] Preferably, a sealing structure is arranged on the cylinder bottom, the sealing structure is close to the top of the cylinder bottom, and the sealing structure is located on the outer side of the cylinder bottom. A sealing structure is arranged at a position close to the top of the cylinder bottom to prevent oil leakage from the cylinder barrel above the cylinder bottom, and the sealing structure is arranged on the outer side of the cylinder bottom to play a sealing role in all directions.

[0013] Preferably, the sealing structure includes a groove arranged on one side of the step at the connection between the cylinder bottom and the cylinder barrel, the groove surrounds the cylinder bottom, and a sealing structure is arranged in the groove. By directly arranging the sealing structure on the cylinder bottom, the structure size of the cylinder bottom is not changed, and at the same time, since the sealing ring is arranged in the groove, it does not affect the installation and disassembly of the cylinder bottom while playing a sealing role.

[0014] Preferably, the sealing ring is an O-ring. The O-ring is very convenient to install, has strong torsion resistance and extrusion resistance, low cost, and is easy to purchase and replace.

[0015] Preferably, a positioning step is provided around the outer side of the cylinder barrel, and the flange sleeve is sleeved on the positioning step. It is convenient for installation and disassembly.

[0016] Preferably, a plurality of screw holes are provided on the flange, and the flange and the cylinder bottom are connected by screws. It has good safety and is convenient for installation.

[0017] Compared with the prior art, the beneficial effects of the present utility model are as follows: (1) The overall structure is simple, and the flange is directly fixed through the key. (2) The flange and the cylinder bottom are connected by screws, which not only prevents the key from falling off but also fixes the flange on the cylinder barrel, making the whole structure simple to process, convenient for installation and disassembly. The flange and cylinder barrel of the flange-cylinder bottom connection structure of this hydraulic cylinder are relatively simple to process, easy to install, and will not increase the diameter of the front end of the cylinder barrel. The cross-sectional shapes of the positioning step and the outer ring groove are convenient for processing and beneficial to assembly. The flange and the cylinder bottom are limited by the key and connected by screws, with reliable safety and convenient assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present utility model.

[0019] Figure 2 is a side view of the present utility model.

[0020] Figure 3 is Figure 1 an enlarged view of part A in

[0021] In the figure: 1, cylinder barrel; 2, flange; 3, limiting body; 31, key; 4, O-ring; 5, screw; 6, cylinder bottom; 7, positioning step; 8, limiting step; 9, outer ring groove; 10, screw hole; 11, groove. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] Next, the thread connection in the cylinder bottom connection of the hydraulic cylinder is divided into two forms: internal thread connection and external thread connection. This structure has beautiful appearance, compact structure, reliable connection, small volume, and light weight. However, the thread and the cylinder barrel require concentricity.

[0023] ​

[0024] External key connection. The key is composed of two semi-circular keys, and the fixation can be achieved with a key cap. This connection structure is compact, has good connection strength, and is relatively convenient for disassembly and assembly. However, the key slot opened at the end of the cylinder barrel weakens the strength of the cylinder wall to some extent. The key for internal key connection is generally composed of three petals, and the cutting plane of the third petal must be parallel to the axis, otherwise the key cannot be inserted. The advantages of this connection are the same as those of the external key connection, but it is inconvenient for disassembly and assembly.

[0025] Flange connection. The end of the cylinder barrel is designed with a flange, and it is connected to the end cover with bolts. The flange and the cylinder barrel can be integral or welded. The integral type is mostly used for cast or forged cylinder barrels, with a large machining allowance and material waste; the welded type is mostly used for steel cylinder barrels, where a seamless steel pipe is welded to the flange. Flange connection has a simple structure, reliable connection, and is convenient for disassembly and assembly. However, the overall dimensions and weight are relatively large.

[0026] Please refer to Figure 1 、 Figure 2 and Figure 3 A connection structure between a cylinder barrel and a cylinder bottom, comprising a cylinder barrel 1 and a cylinder bottom 6. A specific positioning step 7 is designed on the outer side of the cylinder barrel 1 and is tightly connected to the cylinder barrel 1. This positioning step 7 not only provides additional stability for the cylinder barrel 1 but also provides a reference for the installation of subsequent components. A flange 2 is sleeved on the positioning step 7. The flange 2 interacts with the positioning step 7 of the cylinder barrel 1 through the limiting step 8 on its inner side to achieve preliminary fixation. The design of the flange 2 takes into account the fit with the cylinder barrel 1 to ensure the tightness and stability of the connection. A limiting body 3 is installed on the right side of the flange 2 and matches the positioning step 7 of the cylinder barrel 1, providing a reliable positioning surface, enabling the flange 2 to be stably fixed on the cylinder barrel 1. The limiting body 3 includes a key 31, which is the key to achieving precise fixation. The key 31 is designed with specific shapes and dimensions so that it can be inserted into the limiting step 8 and, through interaction with the positioning step 7 on the cylinder barrel 1, achieve the fixation of the flange 2. The flange is directly fixed through the key 31, the limiting step 8, and the positioning step 7 on the cylinder barrel 1. Through the coordinated action of the above components, the connection structure between the cylinder barrel and the cylinder bottom of the present utility model not only realizes convenient positioning and installation but also ensures the reliability and stability of the connection. In addition, this design also has the advantages of being easy to disassemble and maintain, further improving the practicality of the entire structure.

[0027] The keyway 31 of the positioning body 3 is a crucial part of the hydraulic cylinder assembly. Its function is to ensure the correct position of the flange 2 on the cylinder barrel 1 and prevent displacement during operation. The cross-sectional shapes of the outer ring groove 9 and the positioning step 8 are both rectangular. This design simplifies the manufacturing process and provides a clear reference surface for alignment and positioning during assembly. The cross-section of the keyway 31 is also rectangular, and the diameter of the keyway 31 precisely matches the diameters of the outer ring groove 9 and the positioning step 8. This design ensures that the keyway 31 can be smoothly inserted into the outer ring groove 9 and fixed on the positioning step 8, providing a stable positioning effect.

[0028] Please refer to Figure 1 and Figure 2 As shown in [relevant figures], on one side of the step at the connection between the cylinder bottom 6 and the cylinder barrel 1, there is a groove 11, and there is a sealing element in the groove 11. The sealing element is an O-ring 4. One of the important characteristics of the O-ring 4 is its torsional resistance and extrusion resistance. During the operation of the hydraulic cylinder, the cylinder bottom 6 may be subjected to pressures and torques from different directions. The O-ring 4 can adapt to these changes through its own elastic deformation to maintain the sealing effect. The cost of the O-ring 4 is relatively low. The low cost not only reduces the production cost but also enables more flexible maintenance and replacement when the sealing ring is damaged or needs to be replaced. By connecting the O-ring 4 with the cylinder barrel 1, the connection between the O-ring 4 and the cylinder barrel 1 ensures that the hydraulic fluid does not leak from the cylinder barrel 1. This sealing method provides reliable sealing performance without increasing the structural complexity of the cylinder bottom 6. Since the O-ring 4 is arranged in the groove 11, it does not affect the installation and disassembly of the cylinder bottom 6 while playing a sealing role.

[0029] On the outer side of the cylinder bottom 6, there are screw holes 10 arranged at specific intervals and angles to meet the installation requirements of the socket head cap screws 5. The diameter, depth, and position of each screw hole 10 are precisely calculated to achieve the best tightening effect. The screws are socket head cap screws, and socket head cap screws 5 with high torque characteristics are selected. Due to their unique hexagon head design, these screws can achieve a large pre-tightening force under a relatively small torque. This characteristic is particularly important for the high pressures and impact forces generated during the operation of the hydraulic cylinder because it can ensure that the connection remains stable under extreme conditions. The precise fit between the socket head cap screws 5 and the screw holes 10, combined with the high torque characteristics of the socket head cap screws 5, acts on the connection between the flange 2 and the cylinder bottom 6. This design not only provides a very firm connection but also maintains the stability and reliability of the connection under the forces generated during the operation of the hydraulic cylinder. Although the socket head cap screws 5 provide strong fastening force, their design also takes into account the convenience of maintenance and disassembly. A special hexagon wrench can be used to easily tighten or loosen the screws, enabling the quick disassembly and reinstallation between the flange 2 and the cylinder bottom 6.

[0030] In summary, the installation method of the present utility model is as follows.

[0031] First, install the key 31 inside the limit step 8; this step is crucial to ensure the correct positioning of the flange 2; the design of the key 31 allows it to fit tightly on the limit step 8, thus providing a stable support point for the flange 2; then, sleeve the flange 2 onto the positioning step 7 of the cylinder barrel 1 through the key 31; this step is simple and quick to operate, and due to the limiting effect of the key 31, the flange 2 can be accurately positioned on the cylinder barrel 1, ensuring the stability and reliability of the entire structure; after the flange 2 is positioned, next install the cylinder bottom 46 onto the cylinder barrel 1; this step requires ensuring that the contact surface between the cylinder bottom 6 and the cylinder barrel 1 is flat to achieve good sealing performance; use appropriate seals to seal the connection part between the cylinder bottom 6 and the cylinder barrel 1; this step is crucial because it can prevent hydraulic oil leakage and ensure the normal operation and performance of the hydraulic system; finally, connect and fix the flange 2 and the cylinder bottom 6 through the screw 5; this step not only enhances the stability of the overall structure, but also the use of the screw 5 provides a simple connection method, facilitating subsequent disassembly and maintenance; the installation method of the present utility model has multiple advantages, including simple operation, rapid installation, accurate positioning, stable structure, and easy maintenance; these characteristics make the present utility model more efficient and reliable in practical applications.

[0032] The design concept of this utility model lies in simplifying the connection structure of the hydraulic cylinder, improving its reliability and installation efficiency. Through the carefully designed components and connection methods, the optimization of the structure and the enhancement of the function are realized; compared with the traditional hydraulic cylinder, this utility model simplifies the overall structure greatly by directly fixing the flange 2 with the key 31; this design reduces the number of connecting parts, lowers the manufacturing cost, and improves the compactness of the structure at the same time; the connection between the flange 2 and the cylinder bottom 6 adopts the screw 5, this connection method is not only firm and reliable, but also convenient for disassembly and maintenance; the use of the screw 5, combined with the limiting function of the key 31, ensures the stable fixation of the flange 2 on the cylinder barrel 1, preventing loosening or falling off under the high-pressure working environment; the processing technology of the cylinder barrel 1 and the flange 2 of this utility model is simpler and easier to achieve large-scale production; the simplified processing process not only shortens the production cycle, but also reduces the requirements for processing equipment and technology; in addition, the simplified structure also makes the installation process faster, reducing the installation time and cost; the diameter of the front end of the cylinder barrel of this utility model is effectively controlled and does not increase due to the connection of the flange 2, which helps to maintain the compact design of the hydraulic cylinder and is convenient for its use in the space-limited environment; the design of the positioning step 7 and the outer ring groove 9 takes into account the convenience of processing and assembly. Their cross-sectional shapes are easy to process, and at the same time provide good positioning effects during the assembly process, ensuring the precise fit between the flange 2 and the cylinder bottom 6; through the combined use of the key 31 and the screw 5, the connection structure of this utility model has been significantly improved in terms of safety and reliability; the limiting effect of the key 31 and the fastening effect of the screw 5 are combined to form a stable connection system, which can remain stable even in the dynamic load or vibration environment; the simplified structural design is not only convenient for installation, but also for maintenance and upgrade; when it is necessary to replace parts or perform repairs, it can be quickly disassembled and reassembled, reducing the downtime and improving the use efficiency of the equipment.

[0033] On this basis, this utility model also improves the inside of the hydraulic cylinder, please refer to the legend. The piston is installed inside the hydraulic cylinder and is matched with the cylinder barrel 1. The piston rod is connected with the piston through the connecting pin and the snap ring. The way of using the connecting pin and the snap ring can facilitate the assembly and disassembly of the piston and the piston rod, which is convenient for maintenance and replacement of the piston or the piston rod. The connecting pin can also provide a relatively high connection strength and is suitable for withstanding the high pressure and repeated reciprocating motion generated during the operation of the hydraulic cylinder. By adopting the connection method of the connecting pin and the snap ring, a suitable sealing structure can be designed on the piston rod to improve the sealing performance of the hydraulic cylinder, and the way of the connecting pin and the snap ring reduces the manufacturing cost.

[0034] The seal at the piston uses an advanced KDAS combined seal ring. This high-performance sealing system consists of the following key components: a core special-shaped seal ring that is responsible for the main sealing task; two sturdy retaining rings that ensure the stable positioning of the seal ring in a high-pressure environment; and two carefully designed guide support rings that not only guide the piston rod to move in a straight line but also reduce the energy loss caused by friction. This innovative design of the KDAS-type seal ring not only provides excellent sealing effect, effectively avoiding the radial clearance extrusion or distortion of the sealing element under high pressure, but also its compact structural design allows for efficient sealing and guiding functions in a limited space. This design is particularly suitable for the installation environment of closed grooves, enabling the overall length of the piston to be shortened, thus saving costs in the design and manufacturing processes.

[0035] Based on the KDAS combined seal ring, this example further introduces an inner guide ring. The addition of this component significantly reduces the direct contact between the piston rod and the cylinder wall when the piston rod moves in the cylinder, thus significantly reducing the friction coefficient and energy loss. The inner guide ring, as a barrier between the piston and the cylinder wall, effectively prevents the direct contact of metal to metal, greatly reducing wear and extending the service life of the components.

[0036] In addition, the combined use of the guide ring and the piston KDAS combined seal further improves the sealing performance of the hydraulic cylinder, effectively preventing the leakage of hydraulic oil. This sealing solution not only improves the performance and reliability of the hydraulic cylinder but also helps to reduce maintenance costs and extend the service life of the equipment.

[0037] The piston rod and the inside of the piston are sealed with an O-ring. This seal ring is known for its good compressibility and resilience and can quickly return to its original shape after the pressure is released. During the movement of the piston in the hydraulic cylinder, the O-ring can well adapt to the pressure changes brought about by the reciprocating movement of the piston, ensuring the continuity and reliability of the seal.

[0038] To further improve the performance of the piston, the surface of the piston in this example is treated with nickel plating. The nickel layer forms a wear-resistant protective layer on the piston surface with its high hardness, significantly reducing friction and wear. At the same time, the nickel layer has good corrosion resistance to a variety of chemical substances, effectively protecting the piston from the erosion of corrosive substances that may exist in the hydraulic oil. The nickel-plated surface treatment not only makes the piston surface smoother, helps to improve the sealing performance between the piston and the seal, reducing leakage, but also significantly improves the performance of the piston and the overall performance of the hydraulic cylinder, ensuring the long-term stable operation of the system.

[0039] The protection scope of the present utility model is not limited to the specific embodiments described in the text, but is determined by the appended claims and equivalents recognized according to the Patent Law. This means that all technical solutions that are the same as or equivalent to the present utility model in principle and spirit are within the protection scope of the present utility model. Therefore, the innovation and practicality of the present utility model are not only limited to the currently presented form, but also include all possible and reasonable derivations and extensions.

Claims

1. A connecting structure between a hydraulic cylinder flange and the cylinder bottom, comprising a cylinder barrel (1) and a cylinder bottom (6), characterized in that a positioning step (7) is provided on the outer side of the cylinder barrel (1), and a flange (2) is sleeved on the positioning step (7); the positioning step (7) surrounds the outer side of the cylinder barrel (1) of the hydraulic cylinder, and a limiting body (3) is provided on the positioning step (7); a limiting step (8) is provided around the inner side of the flange (2), and the limiting body (3) is installed on one side of the flange (2); the cylinder bottom (6) is provided with a step for tightly connecting with the cylinder barrel (1), and the cylinder bottom (6) is connected to the flange (2) through a connecting member.

2. The hydraulic cylinder flange and cylinder bottom connection structure according to claim 1, characterized in that an outer ring groove (9) is provided around the positioning step (7), and the limiting body is arranged in the outer ring groove (9).

3. The hydraulic cylinder flange and cylinder bottom connection structure according to claim 2, characterized in that, the limiting body (3) includes a key (31), and the cross-sectional shape of the key (31) is rectangular.

4. A hydraulic cylinder flange and cylinder bottom connection structure according to claim 3, characterized in that, the cross-sections of the limiting step (8) and the positioning step (7) are rectangular.

5. A hydraulic cylinder flange and cylinder bottom connection structure according to claim 3 or 4, characterized in that the diameters of the keys (31) respectively match the limiting step (8) and the positioning step (7).

6. A hydraulic cylinder flange and cylinder bottom connection structure according to claim 1, characterized in that, the cylinder bottom (6) is provided with a sealing structure, and the sealing structure is located on one side of the step at the connection between the cylinder bottom (6) and the cylinder barrel (1).

7. A hydraulic cylinder flange and cylinder bottom connection structure according to claim 5, characterized in that, the sealing structure includes a groove (11) on the outer side of the cylinder bottom (6), and a sealing structure is provided in the groove (11).

8. A connecting structure between a hydraulic cylinder flange and a cylinder bottom according to claim 6, characterized in that, the sealing ring used for the sealing structure is an O-ring (4).

9. A hydraulic cylinder flange and cylinder bottom connection structure according to claim 1, characterized in that a plurality of screw holes (10) are provided on the flange (2), and the flange is connected to the cylinder bottom through screws (5).

Images