Double-ejection-rod type hydraulic buffer

Abstract

The invention discloses a double-outlet-rod type hydraulic buffer, relates to the technical field of buffers, and aims to solve the problem that the buffer speed of the buffer is not stable enough when the buffer is subjected to large impact force in the prior art. The invention provides a double-ejection-rod type hydraulic buffer. The double-ejection-rod type hydraulic buffer comprises a cylinder barrel, a guide centering assembly, a piston rod assembly and a cavity. The guide centering assembly comprises a first end cover and a second end cover; the first end cover and the second end cover are installed at the two ends of the cylinder barrel. The piston rod assembly comprises a piston and a piston rod; the piston and the piston rod are of an integrated structure. Piston rods are symmetrically distributed on two sides of the piston; the chamber comprises a first chamber and a second chamber, and the chamber enclosed by the cylinder barrel, the piston and the first end cover is the first chamber; a cavity enclosed by the cylinder barrel, the piston and the second end cover is a second cavity; the inner wall profile curve of the cylinder barrel changes along with the stroke of the piston. According to the buffer, stable buffering can be achieved when the buffer bears large buffering force, and work is reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of buffers, and in particular to a double-rod hydraulic buffer. Background Art

[0002] A buffer is a device used to slow down the collision impact between mechanical parts and mechanical moving mechanisms. It reduces the impact force by extending the impact action time, and at the same time absorbs and converts the kinetic energy of an object, so that the moving mechanism or moving object decelerates smoothly to achieve the buffering purpose.

[0003] Currently, some ejection devices often work in relatively harsh environments and it is difficult to maintain smooth buffering when subjected to large impact forces, which in turn affects the use and reliability of the equipment. Summary of the Invention

[0004] In view of the above analysis, the present invention aims to provide a double-rod buffer to solve the problem that it is difficult to maintain smooth buffering when the equipment working in harsh environments is subjected to large impact forces in the prior art.

[0005] The object of the present invention is mainly achieved by the following technical solutions:

[0006] A double-rod hydraulic buffer includes a cylinder barrel, a guiding and centering assembly, a piston rod assembly and a chamber;

[0007] The guiding and centering assembly includes a first end cover and a second end cover; the first end cover and the second end cover are installed at both ends of the cylinder barrel for closing the oil cylinder;

[0008] The piston rod assembly is arranged inside the cylinder barrel and includes a piston and a piston rod; the piston and the piston rod are of an integral structure; there are two piston rods, which are symmetrically distributed on both sides of the piston and respectively pass through the centers of the first end cover and the second end cover;

[0009] The chamber includes a first chamber and a second chamber. The chamber formed by the cylinder barrel, the piston and the first end cover is the first chamber; the chamber formed by the cylinder barrel, the piston and the second end cover is the second chamber;

[0010] The inner wall contour curve of the cylinder barrel changes with the piston stroke, and the inner wall contour of the cylinder barrel meets the following formula requirements:

[0011]

[0012] where v is the instantaneous velocity of the piston rod, m / s; v0 is the initial velocity of the piston rod, m / s; x is the displacement of the piston rod, m; S is the maximum stroke of the piston rod, m; A0 is the effective area of the piston rod, m 2; δ is the damping clearance height, in m; D is the inner diameter of the cylinder barrel, in m; ΔP is the pressure difference at both ends of the piston, in Pa; B is the perimeter of the damping ring gap, in m; μ is the dynamic viscosity, in Pa·s.

[0013] Further, the piston rod is of a hollow structure.

[0014] Further, the piston rod assembly further includes an impact head, and the impact head is arranged at the end of the piston rod close to the second end cover.

[0015] Further, the guiding and centering assembly further includes a guide sleeve, and the guide sleeve is arranged between the second end cover and the piston rod.

[0016] Further, a reset unit is further included.

[0017] Further, the reset unit includes a reset spring.

[0018] Further, the reset spring is sleeved on the side of the piston rod close to the first end cover.

[0019] Further, one end of the reset spring abuts against the first end cover, and the other end abuts against the piston, for resetting the piston and the piston rod.

[0020] Further, a sealing unit is further included, and the sealing unit includes a dynamic seal and a static seal.

[0021] Further, the dynamic seal is arranged between the first end cover and the second end cover and the piston rod; the static seal is arranged between the first end cover and the second end cover and the cylinder barrel.

[0022] Further, the dynamic seal includes a first dynamic seal, a second dynamic seal and a third dynamic seal; the first dynamic seal and the second dynamic seal are arranged between the piston rod and the first end cover, and the third dynamic seal is arranged between the piston rod and the second end cover, for preventing hydraulic oil from leaking out of the gaps between the piston rod and the first end cover or the second end cover when the piston rod moves; the static seal includes a first static seal and a second static seal, the first static seal is arranged between the cylinder barrel and the first end cover, and the second static seal is arranged between the cylinder barrel and the second end cover, for preventing hydraulic oil from leaking out of the gaps between the cylinder barrel and the first end cover or the second end cover.

[0023] Further, a flange connecting piece is further included, and the flange connecting piece is fixed to the first cylinder head.

[0024] Further, a through hole is arranged in the middle of the flange connecting piece, and the piston rod can pass through the through hole during operation.

[0025] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0026] (1) The present invention adopts a variable throttle ring gap area structure, that is, the diameter of the piston remains unchanged, and the inner wall profile of the cylinder barrel is designed as a curve that changes with the piston stroke, so that the hydraulic buffer can provide a constant pressure. By changing the inner wall profile curve of the cylinder barrel, the gap between the inner wall of the cylinder barrel and the piston is changed in real time, thereby adjusting the pressure peak value in the chamber, making the buffer force uniform even under a large impact force, and the work is stable and reliable. Through the comparison of the buffer characteristic curves, compared with the buffers in the prior art, the buffer of the present invention has a more stable buffer force during the buffering process, and the buffer speed is close to a uniform deceleration form, especially suitable for equipment that is often subjected to large impact forces.

[0027] (2) The piston rod and the piston in the present invention are of an integral structure, which improves the centering effect, reliability and stability between the piston and the piston rod. Both the piston rod and the piston are of a hollow structure, which has a weight reduction effect and can meet the buffering of the hydraulic buffer sleeved on the moving rod working condition, improving the application range of the hydraulic buffer.

[0028] (3) The present invention adopts a double-rod piston assembly. Compared with the single-rod type, it has higher working stability when bearing lateral loads, and can make the buffer structure compact, increasing the capacity of the buffer in a limited space.

[0029] (4) The present invention uses a return spring to realize the rapid reset of the piston and the piston rod, which is efficient and stable. And the return spring is arranged inside the cylinder barrel, which can prevent the spring from rusting and failing.

[0030] (5) The present invention adopts a combination of multiple dynamic seals and static seals for sealing to prevent the sealing failure caused by excessive internal pressure during high-speed impact.

[0031] Other features and advantages of the present invention will be described in the following specification, and part of them will become obvious from the specification, or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structure specifically pointed out in the written specification and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The drawings are only used to illustrate the purpose of the specific invention, and are not considered as a limitation to the present invention. Throughout the drawings, the same reference signs denote the same components.

[0033] Figure 1 It is a schematic diagram of the external structure of the double-rod hydraulic buffer according to a specific embodiment of the present invention;

[0034] Figure 2 It is a schematic cross-sectional view of the double-rod hydraulic buffer according to a specific embodiment of the present invention;

[0035] Figure 3 It is the graph of the buffer force varying with time in a specific embodiment of the present invention;

[0036] Figure 4 It is the graph of the speed varying with time in a specific embodiment of the present invention;

[0037] Figure 5 (a) is the schematic structural diagram of the first static seal, the first dynamic seal and the second dynamic seal in a specific embodiment of the present invention;

[0038] Figure 5 (b) is the schematic structural diagram of the second static seal and the third dynamic seal in a specific embodiment of the present invention.

[0039] Reference numerals:

[0040] 1 - cylinder barrel, 2 - guiding and centering assembly, 201 - first end cover, 202 - second end cover, 203 - guide sleeve, 3 - piston rod assembly, 301 - piston, 302 - piston rod, 303 - impact head, 4 - chamber, 401 - first chamber, 402 - second chamber, 5 - reset unit, 501 - reset spring, 6 - sealing unit, 601 - dynamic seal, 6011 - first dynamic seal, 6012 - second dynamic seal, 6013 - third dynamic seal, 602 - static seal, 6021 - first static seal, 6022 - second static seal, 7 - flange connection member. Specific embodiments

[0041] The following combines the drawings to specifically describe the preferred invention of the present invention, wherein the drawings form a part of the present invention and are used together with the present invention to explain the principle of the present invention.

[0042] This embodiment provides a double - rod hydraulic buffer, see Figure 1 and Figure 2 , including a cylinder barrel 1, a guiding and centering assembly 2, a piston rod assembly 3 and a chamber 4.

[0043] An annular gap is formed between the inner wall of the cylinder barrel 1 and the piston 301, which is the throttling gap, and hydraulic oil can flow in the annular gap. When other conditions remain unchanged, the size of the gap determines the pressure in the chamber 6 and the magnitude of the buffering force. In order to make the buffer operate smoothly during the working process and have a high buffering efficiency, compared with the prior art, this embodiment adopts a variable throttling ring gap area structure, that is, the diameter of the piston 301 remains unchanged, and the inner wall contour of the cylinder barrel 1 is designed as a curve that changes with the stroke of the piston 301, so that the hydraulic buffer can provide a constant pressure. By changing the inner wall contour curve of the cylinder barrel 1, the gap between the inner wall of the cylinder barrel 1 and the piston 301 is changed in real time, thereby adjusting the pressure peak in the chamber 6, so that the buffer can make the buffering force uniform and operate smoothly and reliably even under a large impact force.

[0044] Specifically, the inner wall contour curve of the cylinder barrel 1 refers to the following formula:

[0045]

[0046] wherein, v is the instantaneous velocity of the piston rod 302, m / s; v0 is the initial velocity of the piston rod 302, m / s; x is the displacement of the piston rod 302, m; S is the maximum stroke of the piston rod 302, m; A0 is the effective area of the piston rod 302, m 2 ; δ is the damping gap height, m; D is the inner diameter of the cylinder barrel 1, m; ΔP is the pressure difference between the two ends of the piston, Pa; B is the perimeter of the damping ring gap, m; μ is the dynamic viscosity, Pa·s.

[0047] The variation of the buffering force and buffering speed of the buffer during the working process with time is often used to characterize the buffering performance of the buffer. Figure 3 This is the curve of the buffering pressure of the buffer of the present invention and the buffer in the prior art changing with time. Figure 4 This is the curve of the buffering speed of the buffer of the present invention and the buffer in the prior art changing with time. Among them, the solid line is the buffering force and buffering speed curve of the buffer of the present invention, and the dashed line is the buffering force and buffering speed curve of the buffer in the prior art. Compared with the buffer in the prior art, the buffer of the present invention has a more stable buffering force during the buffering process, and the buffering speed is close to a uniformly decelerated form, which is especially suitable for equipment that is often subjected to large impact forces.

[0048] The guiding and centering assembly 2 includes a first end cover 201, a second end cover 202 and a guide sleeve 203.

[0049] The first end cover 201 and the second end cover 202 are respectively installed at both ends of the cylinder barrel 1 to seal the oil cylinder.

[0050] Through holes are drilled in the middle of the first end cover 201 and the second end cover 202 for the piston rod 302 to pass through.

[0051] The guide sleeve 203 is arranged between the second end cover 202 and the piston rod 302, and is used for guiding and supporting the piston rod 302 to keep the piston rod 302 moving axially within the cylinder barrel 1. At the same time, it cooperates with the sealing unit 5, which can effectively improve the sealing performance of the cylinder barrel 1.

[0052] The piston rod assembly 3 includes a piston 301, a piston rod 302 and a striking head 303.

[0053] The piston 301 is arranged within the cylinder barrel 1, and a double-chamber 4 is formed between the cylinder barrel 1 and the piston 301. Specifically: the chamber surrounded by the cylinder barrel 1, the first end cover 201 and the piston 301 is the first chamber 401, and the chamber surrounded by the cylinder barrel 1, the second end cover 202 and the piston 301 is the second chamber 402. It should be noted that the hydraulic oil is initially arranged in the first chamber 401. The first chamber 401 and the second chamber 402 are connected through the annular gap between the cylinder barrel 1 and the piston 301. When the piston 301 moves towards the first cylinder head, the first chamber 401 is compressed, and the hydraulic oil flows from the gap between the cylinder barrel 1 and the piston 301 to the second chamber 402; when the piston and the piston rod reset, the hydraulic oil flows from the second chamber 402 to the first chamber 401 again.

[0054] Furthermore, the piston 301 and the piston rod 302 are of an integral hollow structure. The integral structure of the piston 301 and the piston rod 302 avoids the detachment between the piston 301 and the piston rod 302, and improves the centering effect, reliability and stability between the piston 301 and the piston rod 302. The hollow structure has a weight reduction effect, and can meet the buffering of the hydraulic buffer when it is sleeved on the moving rod, improving the applicable range of the hydraulic buffer.

[0055] The piston rod 302 is arranged as a double-ended rod type, that is, two symmetrically distributed piston rods 302 are arranged at both ends of the piston 301, and the two piston rods 302 respectively pass through the centers of the first end cover 201 and the second end cover 202, so both chambers 4 are rod chambers.

[0056] In this embodiment, the double-ended rod type piston assembly 3 is adopted. Compared with the single-ended rod type, through the fixation of the two-end guiding and centering structure, the eccentricity of the piston rod can be avoided. It has higher working stability when bearing lateral loads, can improve work efficiency, reduce failure rate, and improve the safety of the equipment. At the same time, the double-ended rod type piston assembly 3 makes the buffer structure compact and increases the capacity of the buffer within the limited space.

[0057] Furthermore, a striking head 303 is installed at one end of the piston rod 302. When an external force impacts, the striking head 303 is first impacted, and then the force is transmitted to the piston rod 302 and the piston 301.

[0058] The reset unit 5 includes a reset spring 501. The reset spring 501 is arranged on the piston rod 302 in the first chamber 401, with one end abutted against the first end cover 201 and the other end abutted against the piston 301. When the piston 301 is subjected to an external force for buffering work, the reset spring 501 is compressed. After the external force disappears, the piston rod 302 and the piston 301 return to their original positions under the action of the reset spring 501. In this embodiment, the reset spring 401 is adopted to realize the rapid reset of the piston 301 and the piston rod 302, which is efficient and stable. Moreover, the reset spring 501 is arranged inside the cylinder barrel 1, which can prevent the spring from rusting and failing.

[0059] As Figure 5 shown, the sealing unit 6 includes a dynamic seal 601 and a static seal 602. The dynamic seal 601 is arranged between the first cylinder head, the second cylinder head and the piston rod 302. Further, the dynamic seal 601 includes a first dynamic seal 6011, a second dynamic seal 6012 and a third dynamic seal 6013. The first dynamic seal 6011 and the second dynamic seal 6012 are arranged between the piston rod 302 and the first end cover 201, and the third dynamic seal 6013 is arranged between the piston rod 302 and the second end cover 202, which is used to prevent hydraulic oil from leaking out of the gap between the piston rod and the first end cover or the second end cover when the piston rod moves. The static seal 602 is arranged between the cylinder barrel 1 and the first cylinder head and the second cylinder head. Further, the static seal 602 includes a first static seal 6021 and a second static seal 6022. The first static seal 6021 is arranged between the first end cover 201 and the cylinder barrel 1, and the second static seal 6022 is arranged between the second end cover 202 and the cylinder barrel 1, which is used to prevent hydraulic oil from leaking out of the gap between the cylinder barrel and the first end cover or the second end cover.

[0060] Figure 5 (a) is a schematic structural diagram of the first static seal 6021, the first dynamic seal 6011 and the second dynamic seal 6012. Figure 5 (b) is a schematic structural diagram of the second static seal 6022 and the third dynamic seal 6013.

[0061] Preferably, the first dynamic seal 5011, the second dynamic seal 5012 and the third dynamic seal 5013 are a combination of Struthers seals, that is, they include a stepped polytetrafluoroethylene sliding ring seal and an O-ring rubber seal. The first static seal 5021 and the second static seal 5022 are O-rings. In this embodiment, a combination of multiple dynamic seals 501 and static seals 502 is adopted for sealing to prevent seal failure caused by excessive internal pressure during high-speed impact.

[0062] Further, the buffer further includes a flange connector 7, which is used to install the buffer on the equipment. The flange connector 7 is fixedly installed on the first cylinder head. A through hole is provided in the middle of the flange connector 7, and the piston rod 302 passing through the first chamber 401 can pass through the through hole during operation, realizing a large-stroke movement and improving the buffer capacity.

[0063] The above are specific embodiments of the present invention. The specific usage method of this embodiment is as follows:

[0064] When the buffer is impacted by an external force, the impact head 303 is impacted first. Then, the impact head 303 transfers the external force to the piston rod 302 and the piston 301. The piston 301 and the piston rod 302 move towards the first cylinder head, making the first chamber 401 smaller, compressing the return spring 401 in the first chamber 401, and squeezing the hydraulic oil in the first chamber 401. At the same time, the hydraulic oil is squeezed out from the annular gap between the piston 301 and the cylinder barrel 1 and enters the second chamber 402. When the piston 301 and the piston rod 302 start to move, since the annular gap between the piston 301 and the inner wall of the cylinder barrel 1 is relatively large, the oil is easily squeezed out; when the piston 301 continues to move, this annular gap becomes smaller and smaller to ensure that the pressure difference at both ends of the piston 301 is as constant as possible during the buffering process until the impact object gradually decelerates to zero speed and the buffering slowly stops. The process of compressing the buffer is a process of the piston 301 squeezing the hydraulic oil to do work. This process consumes a large amount of kinetic energy. When the buffering is completed, the piston 301 is pushed back to the original position by the return spring 501, and the hydraulic oil flows from the second chamber 402 to the first chamber 401, thus completing a working cycle. Due to the curve design of the cylinder barrel 1, the buffer can achieve smooth buffering, improving the buffering efficiency and reliability of the buffer. The buffer of the present invention is particularly suitable for buffering under a large impact force.

[0065] The above description is only the preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A double-rod hydraulic buffer, characterized in that, It includes a cylinder barrel (1), an alignment and guiding component (2), a piston rod component (3) and a chamber (4). The alignment and guiding component (2) includes a first end cover (201) and a second end cover (202); the first end cover (201) and the second end cover (202) are installed at both ends of the cylinder barrel (1) to seal the oil cylinder. The piston rod component (3) is arranged inside the cylinder barrel (1) and includes a piston (301) and a piston rod (302); the piston (301) and the piston rod (302) are of an integral structure; the two piston rods (302) are symmetrically distributed on both sides of the piston (301) and respectively pass through the centers of the first end cover (201) and the second end cover (202). The chamber (4) includes a first chamber (401) and a second chamber (402), and the chamber formed by the cylinder barrel (1), the piston (301) and the first end cover (201) is the first chamber (401); the chamber formed by the cylinder barrel (1), the piston (301) and the second end cover (201) is the second chamber (402).

2. The double-rod hydraulic buffer according to claim 1, characterized in that, The piston rod (302) is of a hollow structure.

3. The double-rod hydraulic buffer according to claim 1, characterized in that The piston rod component (3) further includes an impact head (303), and the impact head (303) is arranged at the end of the piston rod (302) close to the second end cover (202).

4. The double-rod hydraulic buffer according to claim 1, characterized in that, The alignment and guiding component (2) further includes a guide sleeve (203), and the guide sleeve (203) is arranged between the second end cover (202) and the piston rod (302).

5. The double-rod hydraulic buffer according to claim 1, wherein It further includes a reset unit (5).

6. The double-rod hydraulic buffer according to claim 1, characterized in that, The reset unit (5) includes a reset spring (501).

7. The double-rod hydraulic buffer according to claim 6, characterized in that, The reset spring (501) is sleeved on one side of the piston rod (302) close to the first end cover (201).

8. The double-rod hydraulic buffer according to claim 7, characterized in that, One end of the reset spring (501) abuts against the first end cover (201), and the other end abuts against the piston (201) to realize the reset of the piston (201) and the piston rod (202).

9. The double-rod hydraulic buffer according to any one of claims 1-8, characterized in that, It further includes a flange connector (7), and the flange connector (7) is fixed to the first cylinder head (201).

10. The double-rod hydraulic buffer according to claim 9, characterized in that, A through hole is provided in the middle of the flange connector (7), and the piston rod (302) can pass through the through hole during operation.

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