Novel oil cylinder buffering structure

Abstract

The utility model discloses an oil cylinder buffering structure which aims at solving the technical problems that a traditional buffering structure is high in machining precision requirement, short in buffering stroke and incapable of being maintained after being abraded. The structure comprises a cylinder seat, a buffer piston assembly, a cylinder barrel, a main piston, a piston rod, a spring, a floating sleeve and the like. The cylinder wall, close to the cylinder base, of the cylinder barrel is provided with long and thin throttling holes distributed in a crossed mode. The buffer piston assembly is connected with the piston rod through a pull rod, a one-way valve with a steel ball and an eccentric through hole base is arranged in the buffer piston assembly, and hydraulic oil is limited by a throttling hole to form back pressure when the piston rod retracts and is rapidly supplemented through the one-way valve when the piston rod stretches out. In addition, the buffer piston assembly adopts a modular design and can be independently replaced after being abraded, so that the maintenance cost is reduced. Different working condition requirements are met by adjusting (selecting) the throttling hole diameter, the spring rigidity and the buffering stroke, the machining precision requirement is remarkably lowered, the buffering stability is improved, the service life of equipment is prolonged, and the device is suitable for the field of hydraulic machinery.

Description

Technical Field

[0001] This utility model relates to the field of buffer structures for hydraulic cylinders, and specifically to a novel hydraulic cylinder buffer structure. Background Technology

[0002] To prevent a violent impact between the piston rod and cylinder seat during the retraction of a hydraulic cylinder, a buffer structure is often designed to reduce the impact force and vibration. A commonly used buffer structure involves creating a buffer hole in the cylinder seat and using a protruding boss at the end of the piston rod to form a clearance fit. This allows hydraulic oil trapped in the cavity to be discharged through the gap between the boss and the buffer, achieving a throttling and buffering effect.

[0003] Although this structure is simple, it requires extremely high machining precision. It must ensure that after assembly, the piston rod, once fully retracted, has its front boss fully submerged in the buffer hole of the cylinder seat, and the gap between it and the buffer hole cannot be too large, thus reducing the buffering effect. Furthermore, due to the limitations of the cylinder seat size, the buffer boss is generally short, which reduces the buffer stroke and thus the buffering effect. Additionally, if wear, collisions, or other reasons cause the buffer to fail, this structure will be irreparable, rendering the entire cylinder unusable.

[0004] This invention provides a novel buffer structure design that does not require high machining precision. Furthermore, during the design process, different specifications of the throttling orifice diameter, spring stiffness, and buffer distance can be selected according to different buffering requirements, thereby achieving different buffering effects. In addition, if the buffer fails, the corresponding damaged component can be replaced. Utility Model Content

[0005] The purpose of this utility model is to provide a novel hydraulic cylinder buffer structure, which aims to overcome the defects of the prior art and solve the problems of the commonly used buffer structure having extremely high processing precision requirements, being unable to be repaired, and having poor buffering effect.

[0006] Therefore, this utility model proposes a novel hydraulic cylinder buffer structure, including: a cylinder seat, a buffer piston, a cylinder barrel, a main piston, a piston rod, and a tie rod; the cylinder seat is fixedly connected to the cylinder barrel, and the cylinder barrel has at least one set of slender throttling holes on the cylinder wall near the cylinder seat; the buffer piston is disposed between the cylinder seat and the main piston, and has a stepped central hole inside, and is connected to the front end of the piston rod through the tie rod; the buffer piston is provided with a bidirectional sealing ring and a one-way valve structure;

[0007] When the piston rod retracts, the hydraulic oil between the buffer piston and the main piston flows out through the slender throttle orifice to form back pressure, reducing the retraction speed of the piston rod; when the piston rod extends, the hydraulic oil flows into the buffer chamber through the eccentric through-hole of the one-way valve and the slender throttle orifice.

[0008] As a preferred technical solution of this application, the one-way valve includes a steel ball and a base with an eccentric through hole. The steel ball is placed in the valve hole of the buffer piston, and the base is fixed on the buffer piston.

[0009] As a preferred technical solution of this application, the base is fixed to the buffer piston by welding or riveting, and its eccentric through hole allows hydraulic oil to flow into the buffer chamber around the steel ball when the piston rod extends.

[0010] As a preferred technical solution of this application, the elongated throttling orifice is a radially distributed orifice with its spacing set according to the thickness of the buffer piston.

[0011] As a preferred technical solution of this application, the diameter and number of the elongated throttling orifices are configured according to the desired throttling effect.

[0012] As a preferred technical solution of this application, the buffer piston has a detachable modular structure and can be replaced individually after wear.

[0013] As a preferred technical solution of this application, it also includes a spring, a floating sleeve and a spring positioning sleeve. The spring is sleeved on the outside of the cylindrical part of the buffer piston and abuts against the cavity of the piston rod end face through the spring positioning sleeve. The floating sleeve is sleeved on the outside of the spring positioning sleeve.

[0014] As a preferred technical solution of this application, the front end of the pull rod is provided with a boss with an outer diameter larger than the diameter of the step hole of the buffer piston, which is used to drive the buffer piston to move when the piston rod extends to a preset position.

[0015] As a preferred technical solution of this application, the boss of the pull rod is clearance-fitted with the stepped hole of the buffer piston. When the piston rod extends to the preset position, the boss contacts the stepped hole to transmit motion.

[0016] As a preferred technical solution of this application, the floating sleeve moves with the spring positioning sleeve when the piston rod retracts, which is used to limit the radial displacement of the spring positioning sleeve and the spring.

[0017] This invention provides a novel hydraulic cylinder buffer structure that utilizes the hydraulic oil within the cavity between the buffer piston and the main piston, allowing it to exit only through a narrow orifice on the inner wall of the cylinder for throttling and buffering. The buffer piston contains a one-way valve with a steel ball and an eccentric through-hole base. This valve allows the hydraulic oil to flow through the throttling orifice to create back pressure when the piston rod retracts, and to quickly replenish oil through the one-way valve when it extends. Furthermore, the buffer piston assembly adopts a modular design, allowing for individual replacement after wear, reducing maintenance costs. This invention adapts to different working conditions by adjusting (selecting) the throttling orifice diameter, spring stiffness, and buffer stroke, significantly reducing machining accuracy requirements, improving buffering stability, and extending equipment lifespan. It is suitable for the field of hydraulic machinery.

[0018] In addition to the purposes, features, and advantages described above, this application has other purposes, features, and advantages. A further detailed description of this application will be provided below with reference to the figures. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0020] Figure 1 This is a schematic diagram of the hydraulic cylinder buffer structure of this utility model;

[0021] Figure 2 This is a schematic diagram of a buffer piston;

[0022] Figure 3 This is a schematic diagram of the buffering principle of this utility model. Figure 1 ;

[0023] Figure 4 This is a schematic diagram of the buffering principle of this utility model. Figure 2 ;

[0024] Figure 5 This is a schematic diagram of the working of the buffer structure when the piston rod extends according to this utility model;

[0025] The components in the attached diagram are labeled as follows: 1. Cylinder seat; 2. Buffer piston; 3. Cylinder barrel; 4. Main piston; 5. Piston rod; 6. Spring; 7. Floating sleeve; 8. Tie rod; 9. Spring positioning sleeve; 21. Sealing plug; 22. Bidirectional sealing ring; 23. Steel ball; 24. Base; 31. Throttling orifice. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0027] like Figures 1-5 As shown, the novel hydraulic cylinder buffer structure of this utility model includes: cylinder seat 1, buffer piston 2, cylinder barrel 3, main piston 4, piston rod 5, spring 6, floating sleeve 7, pull rod 8, and spring positioning sleeve 9.

[0028] Specifically, the cylinder seat 1 is welded to the cylinder barrel 3. The cylinder seat 1 is provided with an oil port and channel for the flow of hydraulic oil in and out. The cylinder barrel 3 has at least one set of intersecting elongated throttling holes 31 on its cylinder wall near the cylinder seat 1. The spacing of the radially elongated holes is determined according to the thickness of the buffer piston 2. The positions where the elongated holes intersect the inner wall of the cylinder barrel are rounded or polished smooth to prevent the bidirectional sealing ring 22 from scratching its surface and affecting its sealing performance when passing through. The diameter and number of the elongated throttling holes 31 are configured according to the required throttling effect.

[0029] The buffer piston 2 is disposed between the cylinder seat 1 and the main piston 4. The buffer piston 2 has a stepped central hole, and the pull rod 8 passes through the buffer piston 2 and is installed in the bolt hole at the front end of the piston rod 5. A sealing plug 21 is installed at the end of the central hole, and a sealing ring is installed on the sealing plug 21.

[0030] The pull rod 8 has a boss at its front end. The outer diameter of the boss is larger than the diameter of the stepped hole at the end of the buffer piston 2. When the piston rod 5 extends, the pull rod 8 moves to the right to a preset position and then drives the buffer piston 2 to move together. The boss of the pull rod 8 and the stepped hole of the buffer piston 2 are in clearance fit. When the piston rod 5 extends to the preset position, the boss contacts the stepped hole to transmit motion.

[0031] A bidirectional sealing ring is installed on the outer cylindrical surface of the buffer piston 2. A one-way valve is provided on the side of the buffer piston 2. The one-way valve consists of a steel ball 23 and a base 24, with an eccentric through hole on the base 24. The steel ball 23 is placed in the valve hole on the buffer piston, and the base 24 is welded or riveted to the buffer piston. The one-way valve base 24 is fixed to the buffer piston 2 by welding or riveting, and its eccentric through hole allows hydraulic oil to flow into the buffer chamber bypassing the steel ball 23 when the piston rod 5 extends. The buffer piston 2 has a detachable modular structure and can be replaced individually after wear.

[0032] The spring 6 is sleeved on the outer side of the cylindrical portion of the buffer piston 2, and the spring positioning sleeve 9 abuts against the cavity of the piston rod 5 end face. The floating sleeve 7 is sleeved on the outer side of the spring positioning sleeve 9. The stiffness and compression stroke of the spring 6 are adjustable (selectable) to adapt to different buffering strength requirements. The floating sleeve 7 moves with the spring positioning sleeve 9 when the piston rod 5 retracts, and is used to limit the radial displacement of the spring positioning sleeve 9 and the spring 6.

[0033] The working principle and process of the novel hydraulic cylinder buffer structure of this utility model are briefly described below.

[0034] When piston rod 5 retracts, the space between buffer piston 2 and main piston 4 is filled with hydraulic oil, and buffer piston 2 retracts along with main piston 4. After buffer piston 2 touches the end face of cylinder seat 1, main piston 4 continues to retract, compressing the hydraulic oil between it and buffer piston 2. At this time, check valve ball 23 is pressed against the valve hole, and hydraulic oil can only flow out from throttle hole 31 on the cylinder wall; because throttle hole 31 is a narrow hole, the outflow of hydraulic oil decreases rapidly, and back pressure is formed, which rapidly reduces the retraction speed of piston rod 5. As piston rod 5 continues to retract, spring 6 begins to compress, the elastic force increases, and the back pressure of piston rod 5 gradually increases, which gradually reduces the retraction speed of piston rod 5, thereby further increasing the buffering effect.

[0035] When piston rod 5 extends, hydraulic oil pushes check valve ball 23 against check valve base 24. Because check valve base 24 has an eccentric hole, ball 23 cannot form a sealed fit. Hydraulic oil can flow through the valve hole into the cavity between buffer piston 2 and main piston 4. Simultaneously, hydraulic oil also flows through throttle hole 31 into the cavity between buffer piston 2 and main piston 4, thus pushing main piston 4 to extend piston rod 5. At this time, spring 6 begins to rebound, assisting piston rod 5 in extending and reducing the starting pressure of the cylinder. As piston rod 5 extends, the cavity between main piston 4 and buffer piston 2 gradually increases, while hydraulic oil always fills the cavity. When piston rod 5 extends to a certain position, the boss at the front end of pull rod 8 contacts the step at the front end of the stepped hole of buffer piston 2. Pull rod 8 pulls buffer piston 2 to move together. At this time, the volume of the cavity between main piston 4 and buffer piston 2 reaches its maximum, preparing for the next buffering action.

[0036] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A novel hydraulic cylinder buffer structure, characterized in that, include: Cylinder seat (1), buffer piston (2), cylinder barrel (3), main piston (4), piston rod (5), and tie rod (8); The cylinder seat (1) is fixedly connected to the cylinder barrel (3), and at least one set of slender throttling holes (31) are provided on the cylinder wall of the cylinder barrel (3) near the cylinder seat (1); The buffer piston (2) is located between the cylinder seat (1) and the main piston (4), and has a stepped central hole inside. It is connected to the front end of the piston rod (5) through the pull rod (8). The buffer piston (2) is provided with a bidirectional sealing ring (22) and a one-way valve structure; When the piston rod (5) retracts, the hydraulic oil between the buffer piston (2) and the main piston (4) flows out through the slender throttle hole (31) to form back pressure, reducing the retraction speed of the piston rod (5); when the piston rod (5) extends, the hydraulic oil flows into the buffer chamber through the eccentric through hole of the one-way valve and the slender throttle hole (31).

2. The hydraulic cylinder buffer structure according to claim 1, characterized in that: The one-way valve includes a steel ball (23) and a base (24) with an eccentric through hole. The steel ball (23) is placed in the valve hole of the buffer piston (2), and the base (24) is fixed on the buffer piston (2).

3. The hydraulic cylinder buffer structure according to claim 2, characterized in that: The base (24) is fixed to the buffer piston (2) by welding or riveting, and its eccentric through hole allows hydraulic oil to flow into the buffer chamber by bypassing the steel ball (23) when the piston rod (5) extends.

4. The hydraulic cylinder buffer structure according to claim 1, characterized in that: The elongated throttling orifice (31) is a radially distributed orifice with its spacing set according to the thickness of the buffer piston (2).

5. The hydraulic cylinder buffer structure according to claim 1, characterized in that: The diameter and number of the elongated throttling orifices (31) are configured according to the desired throttling effect.

6. The hydraulic cylinder buffer structure according to claim 1, characterized in that: The buffer piston (2) is a detachable modular structure that can be replaced individually after wear.

7. The hydraulic cylinder buffer structure according to claim 1, characterized in that: It also includes a spring (6), a floating sleeve (7) and a spring positioning sleeve (9). The spring (6) is sleeved on the outside of the cylindrical part of the buffer piston (2) and abuts against the cavity of the piston rod (5) end face through the spring positioning sleeve (9). The floating sleeve (7) is sleeved on the outside of the spring positioning sleeve (9).

8. The hydraulic cylinder buffer structure according to claim 7, characterized in that: The front end of the pull rod (8) is provided with a boss with an outer diameter larger than the diameter of the stepped hole of the buffer piston (2), which is used to drive the buffer piston (2) to move when the piston rod (5) extends to the preset position.

9. The hydraulic cylinder buffer structure according to claim 8, characterized in that: The boss of the pull rod (8) is in clearance fit with the stepped hole of the buffer piston (2). When the piston rod (5) extends to the preset position, the boss contacts the stepped hole to transmit motion.

10. The hydraulic cylinder buffer structure according to claim 7, characterized in that: The floating sleeve (7) moves with the spring positioning sleeve (9) when the piston rod (5) retracts, and is used to limit the radial offset of the spring positioning sleeve (9) and the spring (6).

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