Telescopic oil cylinder

Abstract

The utility model discloses a telescopic oil cylinder, and belongs to the technical field of oil cylinders. Comprising a cylinder barrel, a piston rod, a guide cover, a piston, an oil inlet, an oil way hole and an oil return opening, a telescopic cavity is formed in the cylinder barrel and provided with a one-way opening in the axial direction of the cylinder barrel, the guide cover is fixedly arranged at the opening of the telescopic cavity, and one end of the piston rod penetrates through the guide cover, extends into the telescopic cavity and is fixed to the piston. The side, facing the piston rod, of the outer side face of the piston is sleeved with a sealing ring abutting against the inner wall of the telescopic cavity in a sliding mode. The arrangement mode of the oil way holes is changed from a conventional polygonal array structure to a structure arrayed in the circumferential direction of the cylinder barrel, namely linear arrangement, the number of times that the sealing rings on the piston pass through the oil way holes is reduced, and therefore the number of times that the oil way holes make contact with the sealing rings in the telescopic circulation that the piston rod drives the piston each time is reduced, and the service life of the piston is prolonged. The abrasion loss and scratch risk of the sealing ring are reduced, the service life of the sealing ring is prolonged, and the oil leakage condition of the oil cylinder is avoided.

Description

Technical Field

[0001] This utility model relates to a telescopic hydraulic cylinder, belonging to the field of hydraulic cylinder technology. Background Technology

[0002] Cranes are now indispensable equipment in modern industrial production. They are widely used in factories, ports, construction sites, mines, railways, hotels, residential buildings and other places to complete various construction and operations such as lifting, transporting, loading and unloading, installation and personnel transport of materials. In particular, the cranes are equipped with telescopic cylinders on the lifting beams to drive the extension and retraction of the lifting beams.

[0003] In conventional telescopic hydraulic cylinders, the oil passage holes connecting the cylinder body to the oil return port are usually designed as a polygonal array structure, with multiple rows of holes arranged axially along the cylinder body. During the movement of the telescopic hydraulic cylinder, the sealing ring on the piston inside the cylinder will pass through the oil passage holes multiple times. This can cause the sealing ring to be scratched and damaged by the edges of the oil passage holes after long-term use, reducing the sealing performance of the hydraulic cylinder and making it easy for oil leakage to occur, thus posing certain problems. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a telescopic hydraulic cylinder, which solves the problem that in the prior art, when the telescopic hydraulic cylinder is in motion, the sealing ring on the piston inside the cylinder passes through the oil passage hole three times. This causes the sealing ring to be scratched and damaged by the edge of the oil passage hole after long-term use, reducing the sealing performance of the hydraulic cylinder and making it easy to cause oil leakage.

[0005] The technical problem to be solved by this utility model is achieved by the following technical solution: A telescopic cylinder includes a cylinder barrel, a piston rod, a guide cover, a piston, an oil inlet, an oil passage hole, and an oil return port. A telescopic cavity is provided inside the cylinder barrel, and a one-way opening is provided in the telescopic cavity along the axial direction of the cylinder barrel. The guide cover is fixedly provided at the opening of the telescopic cavity. One end of the piston rod passes through the guide cover and extends into the telescopic cavity and is fixed to the piston. A sealing ring is sleeved on the outer side of the piston facing the piston rod and slides against the inner wall of the telescopic cavity. The oil passage hole is opened on the inner wall of the telescopic cavity near the guide cover. Several oil passage holes are arranged in an array along the circumference of the cylinder barrel. The oil return port is opened on the cylinder barrel and communicates with several oil passage holes. The oil inlet is opened on the cylinder barrel opposite the end face where the guide cover is provided, and the oil inlet communicates with the telescopic cavity.

[0006] By adopting the above technical solution, the arrangement of the oil passage holes is changed from the conventional polygonal array structure to a circumferential array structure along the cylinder barrel, i.e., a straight-line arrangement. This reduces the number of times the sealing ring on the piston passes through the oil passage holes, thereby reducing the number of times the oil passage holes contact the sealing ring during each piston rod extension and retraction cycle. This reduces the wear and tear and scratch risk of the sealing ring, which helps to improve the service life of the sealing ring and avoid oil leakage in the oil cylinder.

[0007] The present invention is further configured such that: an oil discharge channel is radially provided on the side of the piston located away from the guide cover and the piston is provided with an oil outlet channel communicating with the oil discharge channel; a liquid guiding chamber is provided in the piston rod communicating with the oil outlet channel; and a pressure oil outlet is provided at the end of the piston rod away from the cylinder, and the pressure oil outlet is communicating with the liquid guiding chamber.

[0008] By adopting the above technical solution, when the sealing ring is excessively worn or scratched, the oil in the telescopic cavity will move out from the gap between the sealing ring and the inner wall of the telescopic cavity into the oil drain channel, and then enter the oil outlet channel through the oil drain channel. After that, it will be discharged through the liquid guide cavity and the pressure oil outlet. When oil appears at the pressure oil outlet, it means that the sealing ring in the cylinder needs to be replaced. At this time, the cylinder can be maintained and the sealing ring replaced. The operation is convenient, and the pressure oil outlet can be observed before use to avoid using a cylinder with a damaged sealing ring. This helps to improve the reliability of the cylinder during operation and avoid problems caused by the cylinder during operation.

[0009] The present invention is further configured such that: a pressure channel is radially provided on the side of the piston located on the side of the sealing ring facing the guide cover; an intermediate channel is provided to connect the pressure channel and the oil outlet channel; a pressure structure is installed in the pressure channel; and the pressure structure closes or connects the pressure channel and the intermediate channel.

[0010] The present invention is further configured such that: the pressure structure includes a sealing block threadedly connected to the pressure channel, the inner wall of the sealing block is provided with a conduction cavity, the two ends of the conduction cavity along the extension direction of the pressure channel are respectively connected to the pressure channel, a sealing ball core is provided in the conduction cavity, the sealing ball core abuts and seals the communication port on the side of the conduction cavity away from the middle channel, and a pressure spring is fixedly provided on the side of the sealing ball core facing the middle channel, the end of the pressure spring away from the sealing ball core abuts and is fixed to the inner wall of the conduction cavity.

[0011] By adopting the above technical solution, when the pressure in the telescopic cavity on the side of the piston facing the guide cover is too high, the pressure difference between the pressure channel and the middle channel increases. Therefore, under the action of the pressure difference, the sealing ball core compresses the pressure spring and releases the sealing ball core from the abutment seal at the opening of the transmission cavity. The oil in the telescopic cavity can enter the transmission cavity through the pressure channel, and then enter the oil outlet channel through the middle channel. It is then sprayed out from the pressure oil outlet through the liquid guide cavity, thereby avoiding the phenomenon of cylinder explosion caused by excessive oil pressure in the telescopic cavity pushing open the guide cover, and improving the stability of the hydraulic cylinder.

[0012] The present invention is further configured such that: an auxiliary oil inlet pipe is provided in the oil outlet channel, the end of the auxiliary oil inlet pipe passes through the piston along the piston rod axis and extends into the telescopic cavity, the other end of the auxiliary oil inlet pipe extends into the liquid guiding cavity, and an auxiliary oil inlet is provided at the end of the piston rod away from the cylinder, and the auxiliary oil inlet pipe is connected to the auxiliary oil inlet.

[0013] The present invention is further configured such that: an oil sealing bolt is connected to the internal thread of the oil inlet, and the connection between the oil sealing bolt and the oil inlet is sealed.

[0014] By adopting the above technical solution, when the hydraulic cylinder is in normal use, the external oil supply line can be connected to the oil inlet, and the external oil return line can be connected to the oil return line. When the installation position of the hydraulic cylinder is limited and the oil supply line cannot be installed in the oil inlet, the oil inlet is sealed by screwing in the oil sealing bolt. Then, the auxiliary oil inlet is connected to the external oil supply line. The oil enters the auxiliary oil inlet pipe through the auxiliary oil inlet and then enters the telescopic cavity on the side of the piston away from the guide cover. At this time, the hydraulic cylinder can operate normally, which improves the applicability of the hydraulic cylinder installation.

[0015] The present invention is further configured such that: an emergency sealing ring is fitted on the outer side of the piston, the emergency sealing ring is located on the side of the sealing ring away from the guide cover, and the emergency sealing ring is hollow and filled with compressed gas.

[0016] By adopting the above technical solution, the compressed gas filling the emergency sealing ring ensures that the emergency sealing ring is always in contact with the telescopic cavity. When the emergency sealing ring becomes thinner due to external wear, the thinned part of the emergency sealing ring will expand under the action of the compressed gas inside the emergency sealing ring. At this time, the emergency sealing ring can always be in contact with the telescopic cavity, ensuring the sealing performance of the piston.

[0017] The beneficial effects of this utility model are: by changing the arrangement of the oil passage holes from the conventional polygonal array structure to a structure arranged in a straight line along the circumference of the cylinder, the number of times the sealing ring on the piston passes through the oil passage holes is reduced, thereby reducing the number of times the oil passage holes contact the sealing ring in each piston rod extension and retraction cycle, reducing the wear and tear and scratch risk of the sealing ring, which helps to improve the service life of the sealing ring and avoid oil leakage in the oil cylinder. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this utility model;

[0019] Figure 2 This is a schematic diagram of the oil passage hole in this utility model from a radial perspective along the cylinder barrel;

[0020] Figure 3 for Figure 1 Enlarged view of the structure at point A in the middle.

[0021] In the diagram: 1. Cylinder; 2. Piston rod; 3. Guide cap; 4. Piston; 5. Oil inlet; 6. Oil passage hole; 7. Oil return port; 8. Telescopic chamber; 9. Fluid guiding chamber; 10. Sealing ring; 11. Emergency sealing ring; 12. Oil drain channel; 13. Auxiliary oil inlet pipe; 14. Auxiliary oil inlet; 15. Pressure oil outlet; 16. Oil outlet channel; 20. Pressure channel; 21. Intermediate channel; 22. Sealing block; 23. Conducting chamber; 24. Sealing ball core; 25. Pressure spring; 26. Oil sealing bolt. Detailed Implementation

[0022] To facilitate a clear understanding of the technical means, creative features, objectives, and effects of this utility model, the following description, in conjunction with specific illustrations, further elaborates on this utility model.

[0023] like Figure 1 and Figure 2 As shown, a telescopic hydraulic cylinder includes a cylinder barrel 1, a piston rod 2, a guide cover 3, a piston 4, an oil inlet 5, an oil passage hole 6, and an oil return port 7. A telescopic cavity 8 is provided inside the cylinder barrel 1, and the telescopic cavity 8 has a one-way opening along the axial direction of the cylinder barrel 1. The guide cover 3 is fixedly installed at the opening of the telescopic cavity 8. One end of the piston rod 2 extends through the guide cover 3 into the telescopic cavity 8 and is fixed to the piston 4. The connection between the piston rod 2 and the guide cover 3 is sealed. A sealing ring 10 is fitted on the outer side of the piston 4 facing the piston rod 2, which slides against the inner wall of the telescopic cavity 8. The sealing ring 10 and the contact surface of the telescopic cavity 8 are sealed. The oil passage hole 6 is opened on the inner wall of the telescopic cavity 8 near the guide cover 3. Several oil passage holes 6 are arranged in an array along the circumference of the cylinder barrel 1. The oil return port 7 is opened on the cylinder barrel 1 and communicates with several oil passage holes 6. The oil inlet 5 is opened on the cylinder barrel 1 on the opposite end face of the guide cover 3, and the oil inlet 5 communicates with the telescopic cavity 8.

[0024] like Figure 1 As shown, piston 4 has a radially arranged oil drain channel 12 on the side of sealing ring 10 away from guide cover 3. Several oil drain channels 12 are arranged circumferentially around piston 4. An oil outlet channel 16 communicating with the oil drain channel 12 is provided inside piston 4. A liquid guiding chamber 9 communicating with the oil outlet channel 16 is provided inside piston rod 2. A pressure oil outlet 15 is provided at the end of piston rod 2 away from cylinder 1, and the pressure oil outlet 15 is connected to the liquid guiding chamber 9. An auxiliary oil inlet pipe 13 is provided inside the oil outlet channel 16. The end of the auxiliary oil inlet pipe 13 passes through piston 4 along the axial direction of piston rod 2 and extends into telescopic cavity 8. The other end of the auxiliary oil inlet pipe 13 extends into liquid guiding chamber 9. An auxiliary oil inlet port 14 is provided at the end of piston rod 2 away from cylinder 1. The surfaces of auxiliary oil inlet port 14 and pressure oil outlet port 15 are adjacent, and auxiliary oil inlet pipe 13 is connected to auxiliary oil inlet port 14. The oil inlet 5 is internally threaded with an oil sealing bolt 26, which seals the connection between the oil sealing bolt 26 and the oil inlet 5.

[0025] like Figure 3As shown, a pressure channel 20 is radially formed on the side of the piston 4 facing the guide cover 3, located on the sealing ring 10. Several pressure channels 20 are formed along the circumference of the piston 4. An intermediate channel 21 is provided to connect the pressure channels 20 and the oil outlet channel 16. A pressure structure is installed inside the pressure channels 20, which can either seal or connect the pressure channels 20 and the intermediate channel 21. The pressure structure includes a sealing block 22 that is threadedly connected to the pressure channels 20. The connection between the sealing block 22 and the pressure channels 20 is sealed. A conduction cavity 23 is formed on the inner wall of the sealing block 22. Both ends of the conduction cavity 23 along the extension direction of the pressure channels 20 are respectively connected to the pressure channels 20. A sealing ball core 24 is provided inside the conduction cavity 23. The sealing ball core 24 abuts and seals the connection port of the conduction cavity 23 away from the intermediate channel 21. A pressure spring 25 is fixedly installed on the side of the sealing ball core 24 facing the intermediate channel 21. The end of the pressure spring 25 away from the sealing ball core 24 abuts and is fixed to the inner wall of the conduction cavity 23.

[0026] like Figure 1 As shown, an emergency sealing ring 11 is fitted on the outer side of the piston 4. The emergency sealing ring 11 is located on the side of the sealing ring 10 away from the guide cover 3. The emergency sealing ring 11 is hollow and filled with compressed gas.

[0027] By changing the arrangement of the oil passage holes 6 from a conventional polygonal array structure to a circumferential array along the cylinder barrel 1, i.e., a straight-line arrangement, the number of times the sealing ring 10 on the piston 4 passes through the oil passage holes 6 is reduced. This reduces the number of times the oil passage holes 6 contact the sealing ring 10 during each extension and retraction cycle of the piston rod 2 driving the piston 4, thereby reducing the wear and tear and scratch risk of the sealing ring 10, which helps to improve the service life of the sealing ring 10 and avoid oil leakage in the oil cylinder.

[0028] When the sealing ring 10 is excessively worn or scratched, the oil in the telescopic cavity 8 will move out from the gap between the sealing ring 10 and the inner wall of the telescopic cavity 8 into the oil drain channel 12, and then enter the oil outlet channel 16 through the oil drain channel 12. After that, it will be discharged through the liquid guide cavity 9 and the pressure oil outlet 15. When oil appears at the pressure oil outlet 15, it means that the sealing ring 10 in the oil cylinder needs to be replaced. At this time, the oil cylinder can be maintained and the sealing ring 10 can be replaced. The operation is convenient. Moreover, by observing the pressure oil outlet 15 before use, the use of an oil cylinder with a damaged sealing ring 10 can be avoided, which helps to improve the reliability of the oil cylinder during operation and avoid problems caused by the oil cylinder during operation.

[0029] When the pressure in the telescopic cavity 8 located on the side of piston 4 facing guide cover 3 is too high, the pressure difference between pressure channel 20 and intermediate channel 21 increases. Therefore, under the action of pressure difference, sealing ball core 24 compresses pressure spring 25 and seals ball core 24 releases its abutment seal at the opening of transmission cavity 23. The oil in telescopic cavity 8 can enter transmission cavity 23 through pressure channel 20, and then enter oil outlet channel 16 through intermediate channel 21, and then be sprayed out from pressure outlet 15 through liquid guide cavity 9. This avoids excessive oil pressure in telescopic cavity 8 from pushing open guide cover 3 and causing cylinder explosion, thus improving the stability of cylinder use.

[0030] When the hydraulic cylinder is in normal use, the external oil supply line can be connected to the oil inlet 5, and the external oil return line can be connected to the oil return port 7. When the installation position of the hydraulic cylinder is limited and the oil supply line cannot be installed in the oil inlet 5, the oil sealing bolt 26 is screwed into the oil inlet 5 to block the oil inlet 5. Then, the auxiliary oil inlet 14 is connected to the external oil supply line. The oil enters the auxiliary oil inlet pipe 13 through the auxiliary oil inlet 14, and then enters the telescopic cavity 8 on the side of the piston 4 away from the guide cover 3. At this time, the hydraulic cylinder can operate normally, which improves the applicability of the hydraulic cylinder installation.

[0031] The compressed gas filling the emergency sealing ring 11 ensures that the emergency sealing ring 11 is always in contact with the telescopic cavity 8. When the emergency sealing ring 11 becomes thinner due to external wear, the thinned part of the emergency sealing ring 11 will expand under the action of the compressed gas inside the emergency sealing ring 11. At this time, the emergency sealing ring 11 can always be in contact with the telescopic cavity 8, ensuring the sealing of the piston 4.

[0032] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of this utility model. All such changes and modifications fall within the scope of protection claimed by this utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A telescopic ram, characterised in that: The cylinder (1) includes a piston rod (2), a guide cover (3), a piston (4), an oil inlet (5), an oil passage (6), and an oil return port (7). A telescopic cavity (8) is provided inside the cylinder (1). The telescopic cavity (8) has a one-way opening along the axial direction of the cylinder (1). The guide cover (3) is fixedly installed at the opening of the telescopic cavity (8). One end of the piston rod (2) passes through the guide cover (3) and extends into the telescopic cavity (8) and is fixed to the piston (4). The outer surface of the piston (4) faces the piston rod. A sealing ring (10) is fitted on one side of the piston rod (2) and slides against the inner wall of the telescopic cavity (8). An oil passage hole (6) is opened on the inner wall of the telescopic cavity (8) near the guide cover (3). Several oil passage holes (6) are arranged in an array along the circumference of the cylinder (1). An oil return port (7) is opened on the cylinder (1) and communicates with several oil passage holes (6). An oil inlet (5) is opened on the cylinder (1) opposite the guide cover (3) and communicates with the telescopic cavity (8).

2. A telescopic ram as claimed in claim 1, wherein: The piston (4) is located on the side of the sealing ring (10) away from the guide cover (3) and has an oil discharge channel (12) in the radial direction. The piston (4) has an oil outlet channel (16) that communicates with the oil discharge channel (12). The piston rod (2) has a liquid guiding chamber (9) that communicates with the oil outlet channel (16). The piston rod (2) has a pressure oil outlet (15) at the end away from the cylinder (1) and the pressure oil outlet (15) communicates with the liquid guiding chamber (9).

3. A telescopic ram as claimed in claim 2, wherein: The piston (4) is located on the side of the sealing ring (10) facing the guide cover (3) and has a pressure channel (20) radially provided. An intermediate channel (21) is provided between the pressure channel (20) and the oil outlet channel (16). A pressure structure is installed in the pressure channel (20) and the pressure structure can close or connect the pressure channel (20) and the intermediate channel (21).

4. A telescopic ram as claimed in claim 3 wherein: The pressure structure includes a sealing block (22) threadedly connected to the pressure channel (20). The inner wall of the sealing block (22) is provided with a conduction cavity (23). The two ends of the conduction cavity (23) along the extension direction of the pressure channel (20) are respectively connected to the pressure channel (20). A sealing ball core (24) is provided in the conduction cavity (23). The sealing ball core (24) abuts and seals the communication port of the conduction cavity (23) away from the middle channel (21). A pressure spring (25) is fixedly provided on the side of the sealing ball core (24) facing the middle channel (21). The end of the pressure spring (25) away from the sealing ball core (24) abuts and is fixed to the inner wall of the conduction cavity (23).

5. The telescopic ram as defined in claim 2, wherein: An auxiliary oil inlet pipe (13) is provided in the oil outlet channel (16). The end of the auxiliary oil inlet pipe (13) extends through the piston (4) along the piston rod (2) and into the telescopic cavity (8). The other end of the auxiliary oil inlet pipe (13) extends into the liquid guiding cavity (9). An auxiliary oil inlet port (14) is provided at the end of the piston rod (2) away from the cylinder (1). The auxiliary oil inlet pipe (13) is connected to the auxiliary oil inlet port (14).

6. The telescopic ram as defined in claim 1, wherein: The oil inlet (5) is internally threaded with an oil sealing bolt (26), and the connection between the oil sealing bolt (26) and the oil inlet (5) is sealed.

7. The telescopic ram as defined in claim 1, wherein: The piston (4) is sleeved with an emergency sealing ring (11) on the outer side, the emergency sealing ring (11) is located on the side away from the guide cover (3) of the sealing ring (10), and the emergency sealing ring (11) is hollow and filled with compressed gas.

Images