Self-pressure-relief buffer cavity type hydraulic oil cylinder

Abstract

The utility model relates to the technical field of hydraulic oil cylinders, in particular to a self-pressure-relief buffer cavity type hydraulic oil cylinder. A self-pressure-relief buffering cavity type hydraulic oil cylinder comprises a cylinder body assembly, a piston and a piston rod, the cylinder body assembly comprises an end cover and a cylinder body, the piston is installed at one end of the piston rod located in the cylinder body, the other end of the piston rod extends out of the cylinder body from the end cover, and a buffering sleeve is arranged at the position, close to the piston, of the piston rod. A plurality of mounting holes are evenly formed in the inner end face of the end cover, pressure release valve assemblies are arranged in the mounting holes, and the mounting holes communicate with the oil port. The arranged hydraulic valve assembly plays a buffering role in the early stage and plays a pressure relief role after the buffering process is completed, the problem that the service life of the oil cylinder is shortened due to too high buffering pressure is solved, and the buffering effect is not affected; the whole structure is simple and compact; the structure that the pressure release valve assembly is arranged in the end cover is adopted, the stress area of the pressure release valve body is small, and cost is low; and the pressure relief valve assemblies are uniformly distributed, so that the pressure relief accuracy and safety of the pressure relief valve assemblies are improved.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic cylinder technology, and in particular to a self-relieving buffer chamber type hydraulic cylinder. Background Technology

[0002] Currently, when hydraulic cylinders are equipped with effective buffer structures / devices, the buffer pressure often rises to 90-120 MPa or even above 140 MPa. Excessive buffer pressure can cause end cap fatigue, significantly reducing the end cap's service life. Taking the cylinder end cap buffer zone as an example, the buffer zone is designed in the end cap area, and the end cap material is generally metal. During each buffering cycle, the buffer zone undergoes a continuous high-pressure pulse fatigue process. Therefore, the better the buffering effect, the higher the buffer pressure, and the drastically shorter the lifespan.

[0003] Existing hydraulic cylinders generally require the use of throttle valves and unloading valves or the fit clearance between buffer sleeves, buffer rings, and end caps to control the maximum buffer pressure. This approach sacrifices the buffering effect to reduce the buffer pressure, resulting in a complex structure and high cost. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a self-relieving buffer chamber hydraulic cylinder in order to solve the problems existing in the prior art in the background art.

[0005] The technical solution adopted by this utility model to solve its technical problem is: a self-relieving buffer chamber hydraulic cylinder, including a cylinder body assembly, a piston and a piston rod. The cylinder body assembly includes an end cover and a cylinder body. The piston is installed at one end of the piston rod located inside the cylinder body. The other end of the piston rod extends out of the cylinder body from the end cover. A buffer sleeve is provided on the piston rod near the piston. An oil port is opened on the end cover. A plurality of mounting holes are evenly opened on the inner end face of the end cover. A pressure relief valve assembly is provided in the mounting hole, and the mounting hole communicates with the oil port.

[0006] Furthermore, the mounting hole is a variable diameter through hole, including a large diameter section and a small diameter section. The pressure relief valve assembly is installed in the large diameter section, and the large diameter section and the small diameter section form a stop step.

[0007] Furthermore, the pressure relief valve assembly consists of a pressure relief valve seat, a pressure relief valve body, and a pressure relief valve spring. The pressure relief valve body is connected to the pressure relief valve seat. One end of the pressure relief valve body is open, and the longitudinal section of the other end has a Y-shaped structure. One end of the pressure relief valve spring is located inside the pressure relief valve body, and the other end is tightly pressed against the stop step.

[0008] Furthermore, pressure equalization grooves are evenly distributed on the outer wall of the pressure relief valve body.

[0009] Furthermore, an oil passage hole is formed around the valve body of the pressure relief valve near the valve seat.

[0010] Furthermore, the cylinder block assembly also includes a cylinder head flange, and the end cap is mounted on one end of the cylinder block via the cylinder head flange.

[0011] Furthermore, a sealing ring is provided at the connection between the cylinder head flange and the end cover.

[0012] Furthermore, an oil pipe is connected to the oil port, and the oil pipe extends along the outer wall of the cylinder body to the other end away from the end cap.

[0013] Furthermore, the cylinder body is provided with a limiting component for the limiting oil pipe.

[0014] The beneficial effects of this utility model are:

[0015] The hydraulic valve assembly of this invention plays a buffering role in the early stage and a pressure relief role after the buffering process is completed, which solves the problem of excessive buffering pressure reducing the life of the oil cylinder without affecting the buffering effect; the overall structure is simple and compact.

[0016] The structure uses an end cap with a built-in pressure relief valve assembly, and the pressure relief valve body has a small force-bearing area and low cost; the evenly distributed design of the pressure relief valve assembly improves the accuracy and safety of pressure relief. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

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

[0019] Figure 2 This is a cross-sectional view of the present invention at the end of its stroke.

[0020] Figure 3 yes Figure 2 A magnified structural diagram of point I in the middle.

[0021] Figure 4 This is a schematic diagram of the structure of the pressure relief valve body in this utility model.

[0022] Figure 5 This is a partial cross-sectional view of the present invention during the pre-buffering process.

[0023] Figure 6 This is a partial cross-sectional view of the present invention during the buffering and depressurization process.

[0024] In the diagram: 1. Piston; 2. Piston rod; 3. End cap; 4. Cylinder body; 5. Cylinder head flange; 6. Sealing ring; 7. Buffer sleeve; 8. Oil port; 9. Pressure relief valve assembly; 11. Oil pipe; 12. Limiting element; 31. Mounting hole; 311. Large diameter bore section; 312. Small diameter bore section; 313. Stop step; 91. Pressure relief valve seat; 92. Pressure relief valve body; 921. Pressure equalizing groove; 922. Oil passage hole; 93. Pressure relief valve spring. Detailed Implementation

[0025] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the present invention, and therefore only show the components relevant to the present invention.

[0026] like Figure 1 and Figure 2 As shown, a self-relieving buffer chamber type hydraulic cylinder includes a cylinder body assembly, a piston 1, and a piston rod 2. The cylinder body assembly includes an end cap 3, a cylinder body 4, and a cylinder head flange 5. The end cap 3 is installed at one end of the cylinder body 4 via the cylinder head flange 5, and a sealing ring 6 is provided at the connection between the cylinder head flange 5 and the end cap 3. The piston 1 is installed at one end of the piston rod 2 located inside the cylinder body 4, and the other end of the piston rod 2 extends out of the cylinder body 4 from the end cap 3. A buffer sleeve 7 is provided on the piston rod 2 near the piston 1. An oil port 8 is provided on the end cap 3, and an oil pipe 11 is connected to the oil port 8. The oil pipe 11 extends along the outer wall of the cylinder body 4 to the other end away from the end cap 3. A limiting member 12 is provided on the cylinder body 4 to limit the oil pipe 11 (the limiting member 12 shown in the figure is a clamp structure, but other structures can also be used, as long as the oil pipe 11 is limited on the cylinder body 4).

[0027] The end cap 3 has several mounting holes 31 evenly distributed on its inner end face. Each mounting hole 31 contains a pressure relief valve assembly 9, and the mounting holes 31 are connected to the oil port 8. The multiple pressure relief valve assemblies 9 are evenly distributed on the end cap 3, which can ensure the pressure relief rate and flow capacity, and also ensure that when one pressure relief valve assembly 9 malfunctions, the other pressure relief valve assemblies 9 can still function normally.

[0028] like Figure 3 As shown, the mounting hole 31 is a variable diameter through hole, including a large diameter hole section 311 and a small diameter hole section 312. The pressure relief valve assembly 9 is installed in the large diameter hole section 311, and the large diameter hole section 311 and the small diameter hole section 312 form a stop step 313.

[0029] The pressure relief valve assembly 9 consists of a pressure relief valve seat 91, a pressure relief valve body 92, and a pressure relief valve spring 93. The pressure relief valve body 92 is connected to the pressure relief valve seat 91, as shown below. Figure 4As shown, one end of the pressure relief valve body 92 is open, and the longitudinal section of the other end has a Y-shaped structure. One end of the pressure relief valve spring 93 is located inside the pressure relief valve body 92, and the other end is tightly pressed against the stop step 313. Pressure equalizing grooves 921 are evenly distributed on the outer wall of the pressure relief valve body 92. The pressure equalizing grooves 921 ensure that the pressure on the pressure relief valve body 92 is equal everywhere, preventing the pressure relief valve body 92 from getting stuck due to uneven pressure, thereby maintaining the stable position of the pressure relief valve body 92 in the oil. The pressure equalizing grooves 921 help maintain the pressure relief valve body 92 in the middle position, reduce internal leakage, and improve the performance of the pressure relief valve assembly 9. A ring of oil passage holes 922 is formed on the pressure relief valve body 92 near the pressure relief valve seat 91, allowing pressurized oil to enter the pressure relief valve body 92 more smoothly.

[0030] The pressure relief valve assembly 9 in this embodiment is very small in size, so its opening area is also very small. This also reduces the wire diameter of the pressure relief valve spring 93, making it easy to install and operate.

[0031] like Figure 5 As shown, the initial buffering process: When the buffer sleeve 7 moves into the end cover 3 with the piston rod 2, a gap throttling buffer is formed. The oil in the cavity formed between the piston 1 and the end cover 3 flows into the oil port 8 through the two small gaps shown in the figure, and then flows back through the oil pipe 11. At this time, the oil cylinder decelerates. During the buffering process, if the pressure in the cavity formed between the piston 1 and the end cover 3 is too high, the pressurized oil acts on the pressure relief valve body 92 through the pressure relief valve seat 91 and compresses the pressure relief valve spring 93. It then forms a smooth pressure relief channel through the oil hole 922 to the oil port 8, completing the pressure relief process. Figure 6 As shown; that is, in this process, the buffer sleeve 8 and the end cap 3 complete the pre-buffering process, and the pressure relief valve assembly 9 completes the pressure relief protection process.

[0032] Based on the above-described preferred embodiments of this utility model, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the technical concept of this utility model. The technical scope of this utility model is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A self-relieving buffer chamber type hydraulic cylinder, comprising a cylinder body assembly, a piston (1) and a piston rod (2), the cylinder body assembly comprising an end cap (3) and a cylinder body (4), the piston (1) being mounted on one end of the piston rod (2) located within the cylinder body (4), and the other end of the piston rod (2) extending out of the cylinder body (4) from the end cap (3), characterized in that: A buffer sleeve (7) is provided on the piston rod (2) near the piston (1), and an oil port (8) is provided on the end cap (3). Several mounting holes (31) are evenly provided on the inner end face of the end cap (3). A pressure relief valve assembly (9) is provided in the mounting hole (31), and the mounting hole (31) is connected to the oil port (8).

2. The self-relieving buffer chamber hydraulic cylinder according to claim 1, characterized in that: The mounting hole (31) is a variable diameter through hole, including a large diameter hole section (311) and a small diameter hole section (312). The pressure relief valve assembly (9) is installed in the large diameter hole section (311), and the large diameter hole section (311) and the small diameter hole section (312) form a stop step (313).

3. The self-relieving buffer chamber hydraulic cylinder according to claim 2, characterized in that: The pressure relief valve assembly (9) consists of a pressure relief valve seat (91), a pressure relief valve body (92), and a pressure relief valve spring (93). The pressure relief valve body (92) is connected to the pressure relief valve seat (91). One end of the pressure relief valve body (92) is open, and the longitudinal section of the other end is Y-shaped. One end of the pressure relief valve spring (93) is located inside the pressure relief valve body (92), and the other end is pressed against the stop step (313).

4. The self-relieving buffer chamber hydraulic cylinder according to claim 3, characterized in that: The pressure relief valve body (92) has pressure equalization grooves (921) evenly distributed on its outer side wall.

5. The self-relieving buffer chamber hydraulic cylinder according to claim 3, characterized in that: An oil passage hole (922) is provided on the valve body (92) near the valve seat (91) of the pressure relief valve.

6. The self-relieving buffer chamber hydraulic cylinder according to claim 1, characterized in that: The cylinder assembly also includes a cylinder head flange (5), and the end cap (3) is mounted on one end of the cylinder (4) via the cylinder head flange (5).

7. The self-relieving buffer chamber hydraulic cylinder according to claim 6, characterized in that: A sealing ring (6) is provided at the connection between the cylinder head flange (5) and the end cover (3).

8. The self-relieving buffer chamber hydraulic cylinder according to claim 1, characterized in that: The oil port (8) is connected to an oil pipe (11), which extends along the outer wall of the cylinder body (4) to the other end away from the end cap (3).

9. The self-relieving buffer chamber hydraulic cylinder according to claim 8, characterized in that: The cylinder body (4) is provided with a limiting member (12) for the limiting oil pipe (11).

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