A large flow hydraulic system and its buffer valve

Abstract

The present invention provides a large flow hydraulic system and a buffer valve thereof, the buffer valve comprising: a valve body having a valve chamber, the two ends of the valve chamber being a liquid inlet and a liquid outlet; a valve plug movably arranged in the valve chamber of the valve body; the valve plug separates the valve chamber into a mutually sealed connecting chamber and a liquid discharge chamber; a buffer portion is arranged on the valve plug, the buffer portion separates the connecting chamber into a middle chamber and a liquid outlet chamber; the middle chamber and the liquid outlet chamber are connected through a buffer hole on the buffer portion; the liquid outlet, the liquid outlet chamber, the middle chamber are connected with the liquid inlet; the liquid discharge chamber is connected with the outside of the valve body. After the liquid flows into the liquid outlet chamber, the pressure of the liquid outlet chamber increases, forming a pressure difference with the liquid discharge chamber, thereby pushing the valve plug to move in the direction of the liquid inlet, and the opening of the buffer hole increases linearly, so that the huge flow impact when the directional valve is opened is buffered.

Description

Technical Field

[0001] The invention relates to the field of hydraulic system control, and in particular to a large-flow hydraulic system and a buffer valve thereof. Background Art

[0002] In a large flow hydraulic system, the moment the directional valve is opened, it will cause a very large impact, resulting in severe vibration of the pipeline, resulting in oil pipe rupture, loose fasteners, seal failure, hydraulic component damage, etc. The existing solution is usually to use a combination of multiple cartridge valves to open them in sections, first open the small flow valve, then open the large flow valve to reduce the switching impact, which is generally implemented in 2 sections, or even 3 sections or more. Figure 1 As shown, the conventional cartridge valve group includes a valve block 1, a conventional cartridge valve 2 arranged in the valve block 1, a pilot solenoid valve 3, and a regulating rod 4. Figure 2 As shown, the conventional cartridge valve includes a valve body 21 and a valve core 22 disposed in the valve body 21, a valve port 23 is provided on the valve body 21, and the valve core 22 is connected to the regulating rod 4. The conventional cartridge valve group controls the stroke of the regulating rod 4 by the pilot solenoid valve 3, thereby controlling the distance between the valve core 22 and the valve port 23, and adjusting the flow area of ​​the valve port 23. The flow areas of the valve ports of the multiple conventional cartridge valves in the large flow hydraulic system using a combination of multiple cartridge valves increase in sequence. The valve ports with different flow areas are opened in sequence, and the flow areas increase in sequence. This buffering method is not linearly increasing, but step-by-step increasing. There is still a great impact when the conventional cartridge valve is opened in sections. At the same time, due to the use of multiple valves, the oil circuit is more complicated and the structure is bulky, which increases the cost. Summary of the invention

[0003] In order to solve the problem of huge flow impact generated at the moment of opening of a directional valve in a large flow hydraulic system, the present invention provides a buffer valve, which can buffer the huge flow impact when the directional valve is opened and has a simple structure.

[0004] In order to solve the above technical problems, the technical solution created by the present invention is implemented as follows:

[0005] A buffer valve, comprising:

[0006] A valve body having a valve chamber, two ends of which are respectively a liquid inlet and a liquid outlet;

[0007] A valve plug is movably disposed in the valve chamber; the valve plug separates the valve chamber into a communicating chamber and a drain chamber that are sealed from each other;

[0008] The valve plug is provided with a buffer portion, which divides the communication cavity into a middle cavity and a liquid outlet cavity; the buffer portion is provided with a buffer hole, through which the middle cavity and the liquid outlet cavity are communicated; the liquid outlet, the liquid outlet cavity, the middle cavity and the liquid inlet are communicated; the liquid discharge cavity is communicated with the outside of the valve body;

[0009] When the valve plug moves toward the liquid inlet, the opening of the buffer hole increases linearly, and the volume of the liquid drainage cavity decreases.

[0010] When the buffer valve of the present invention is in working state, after the liquid flows through the liquid inlet, the middle cavity, and the buffer hole into the liquid outlet cavity, the pressure of the liquid outlet cavity rises, thereby forming a negative pressure in the liquid discharge cavity connected to the outside relative to the liquid outlet cavity. At the same time, since the volume of the liquid discharge cavity decreases when the valve plug moves toward the liquid inlet, the valve plug can move toward the liquid inlet under the pressure of the liquid to reduce the volume of the liquid discharge cavity until the pressure in the liquid discharge cavity is equal to the pressure in the liquid outlet cavity or the valve plug is blocked and stops moving. During the movement of the valve plug, the opening of the buffer hole increases linearly, which can increase the flow rate of the liquid when it flows through the buffer valve linearly, thereby buffering the huge flow impact when the directional valve is opened. In addition, the valve plug of the buffer valve of the present invention is driven by the oil circuit pressure, and no additional control oil circuit is required. It has a simple structure and low manufacturing cost. In actual operation, the pressure of the liquid outlet cavity of the buffer valve rises very quickly, and the valve plug completes the movement in a very short time, which has little effect on the movement speed of the oil circuit.

[0011] Furthermore, the width of the buffer hole gradually increases along the direction from the liquid inlet to the liquid outlet, and the overall shape is "V". When the valve plug moves toward the liquid inlet, the overall shape of the buffer hole is "V", and the overlap area of ​​the buffer hole and the middle cavity increases linearly, that is, the opening of the buffer hole increases linearly.

[0012] Furthermore, the buffer portion is a hollow cylinder, one end of which is open toward the liquid outlet, and the other end of which is provided with a partition; the partition separates the valve plug into a connecting portion and the buffer portion; the connecting portion is a hollow cylinder, one end of which is open toward the liquid inlet, and the other end of which is connected to the partition; a connecting hole is provided on the connecting portion, and the connecting portion is connected with the central cavity through the connecting hole.

[0013] Thus, the liquid flows into the valve chamber from the liquid inlet, then flows through the connecting portion, the connecting hole, the middle cavity, the buffer hole, the liquid outlet cavity, and finally flows out of the valve chamber from the liquid outlet.

[0014] Furthermore, a step is provided on the outer surface of the valve plug, and the step divides the valve plug as a whole into a first valve plug section and a second valve plug section; the outer diameter of the first valve plug section is larger than the outer diameter of the second valve plug section, and the first valve plug section is arranged close to the liquid outlet, and the second valve plug section is arranged close to the liquid inlet; when the valve plug is arranged in the valve chamber, the step is located in the drainage cavity.

[0015] Since the outer diameter of the first valve plug section is greater than the outer diameter of the second valve plug section, the first valve plug section and the second valve plug section form an area difference, and when the valve plug moves toward the liquid inlet, the volume of the liquid discharge chamber is compressed. Since when the valve plug is arranged in the valve chamber, the step is located in the liquid discharge chamber, when the pressure of the liquid outlet chamber rises, once the valve plug is pushed, the volume of the liquid discharge chamber begins to decrease, thereby promoting the pressure of the liquid outlet chamber to continue to push the valve plug toward the liquid inlet, until the pressure in the liquid discharge chamber is equal to the pressure in the liquid outlet chamber or the valve plug is blocked and stops moving.

[0016] Furthermore, a first valve chamber section is connected between the connecting chamber and the drainage chamber, and an inner diameter of the first valve chamber section matches the first valve plug section of the valve plug, so that the first valve plug section is in close contact with the inner wall of the first valve chamber section; a second valve chamber section is connected between the liquid inlet and the drainage chamber, and an inner diameter of the second valve chamber section matches the second valve plug section of the valve plug, so that the second valve plug section is in close contact with the inner wall of the second valve chamber section.

[0017] By setting the inner diameters of the first and second valve chamber sections to match the valve plug, the valve plug can always be in close contact with the inner wall of the valve chamber during operation, which can prevent liquid from directly entering the drainage chamber through the gap between the valve plug and the inner wall of the valve chamber, resulting in the drainage chamber being unable to form a low pressure, and further causing the valve plug to be unable to be pushed.

[0018] Furthermore, the first and second valve chamber sections are both provided with grooves, a dynamic sealing ring is arranged in the groove, and the dynamic sealing ring is in close contact with the valve plug.

[0019] Dynamic sealing rings are arranged at both ends of the liquid discharge chamber to further prevent liquid from entering the liquid discharge chamber through the gap between the valve plug and the valve chamber.

[0020] Furthermore, an elastic element is provided in the communication portion, and the valve plug is close to the liquid outlet under the elastic force of the elastic element. By providing the elastic element, when the buffer valve is in a non-working state, the valve plug is reset under the elastic action of the elastic element and close to the liquid outlet, thereby providing sufficient space for the valve plug to move toward the liquid outlet, so that the opening of the buffer hole can change from the minimum to the maximum, so that the liquid flow is buffered.

[0021] Furthermore, the valve body is provided with a drainage hole extending in the radial direction of the valve body, one end of the drainage hole is connected to the drainage cavity, and the other end thereof is connected to the outside of the valve body. By providing the drainage hole, the drainage cavity is connected to the outside of the valve body, ensuring that a pressure difference can be formed between the drainage cavity and the liquid outlet cavity. Even if liquid enters the drainage cavity from the gap between the valve plug and the valve body, the liquid can be discharged through the drainage hole, preventing the liquid from being retained in the drainage cavity and increasing the pressure of the drainage cavity.

[0022] Furthermore, the two ends of the buffer valve are respectively connected with an inlet flange and an outlet flange; the inlet flange is provided with a through hole facing the liquid inlet; the outlet flange is provided with a through hole facing the liquid outlet, and the first valve plug section of the valve plug is against the end face of the outlet flange.

[0023] The present invention also provides a large-flow hydraulic system, which includes the buffer valve described in any one of the above items, as well as a hydraulic cylinder and a cartridge valve; the liquid inlet of the buffer valve is connected to the cartridge valve, and the liquid outlet of the buffer valve is connected to the hydraulic cylinder.

[0024] Compared with the prior art, the buffer valve of the present invention can transform the huge flow impact when the directional valve is opened into a linear increase, avoid severe vibration of the pipeline, and has the characteristics of fast response speed. In addition, the valve plug of the buffer valve of the present invention is driven by the oil circuit pressure, and no additional control oil circuit is required. It has a simple structure and low manufacturing cost. The buffer valve of the present invention has a compact structure and can be directly installed in the pipeline, which is very convenient to install and use. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0026] Figure 1 is a cross-sectional view of a conventional cartridge valve group in the prior art;

[0027] Figure 2 is a cross-sectional view of a conventional cartridge valve of the prior art;

[0028] Figure 3 is a cross-sectional view of a buffer valve according to Embodiment 1 of the present invention;

[0029] Figure 4 is a cross-sectional view of a valve body according to Embodiment 1 of the present invention;

[0030] Figure 5 is a three-dimensional diagram of a valve plug according to Embodiment 1 of the present invention;

[0031] Figure 6 is a cross-sectional view of the valve plug of Example 1 of the present invention;

[0032] Figure 7 It is a schematic diagram of a large flow hydraulic system according to Embodiment 2 of the present invention.

[0033] Among them, 1. valve block, 2. conventional cartridge valve, 3. pilot solenoid valve, 4. adjusting rod, 5. buffer valve, 6. cartridge valve, 7. hydraulic cylinder, 21. valve body, 22. valve core, 23. valve port, 51. valve body, 52. valve chamber, 53. valve plug, 54. elastic element, 55. dynamic sealing ring, 56. drainage hole, 57. inlet flange, 58. outlet flange, 59. static sealing ring, 521. liquid inlet, 522. liquid outlet, 523. middle cavity, 524. drainage cavity, 525. liquid outlet cavity, 526. first valve chamber section, 527. second valve chamber section, 531. buffer part, 532. buffer hole, 533. first valve plug section, 534. second valve plug section, 535. connecting part, 536. connecting hole, 537. step, 538. partition. DETAILED DESCRIPTION

[0034] In order to solve the problem of huge flow impact generated at the moment of opening of a directional valve in a large flow hydraulic system, the present invention provides a buffer valve, which can buffer the huge flow impact when the directional valve is opened and has a simple structure.

[0035] Example 1

[0036] like Figures 3 to 6 As shown, the buffer valve 5 of the present invention includes a valve body 51, which has a valve chamber 52, and two ends of the valve chamber 52 are respectively a liquid inlet 521 and a liquid outlet 522;

[0037] A valve plug 53 is movably disposed in the valve chamber 52; the valve plug separates the valve chamber 52 into a communicating chamber and a drain chamber 524 which are sealed from each other;

[0038] The valve plug 53 is provided with a buffer portion 531, and the buffer portion 531 divides the communication cavity into a middle cavity 523 and a liquid outlet cavity 525; the buffer portion 531 is provided with a buffer hole 532, and the middle cavity 523 and the liquid outlet cavity 525 are connected through the buffer hole 532; the liquid outlet 522, the liquid outlet cavity 525, and the middle cavity 523 are connected to the liquid inlet 521; the liquid discharge cavity 524 is connected to the outside of the valve body 51;

[0039] When the valve plug 53 moves toward the liquid inlet 521 , the opening of the buffer hole 532 increases linearly, and the volume of the liquid discharge cavity 524 decreases.

[0040] When the buffer valve 5 of the present invention is in working state, after the liquid flows through the liquid inlet 521, the middle cavity 523, and the buffer hole 532 into the liquid outlet cavity 525, the pressure of the liquid outlet cavity 525 rises, thereby forming a negative pressure in the liquid discharge cavity 524 connected to the outside relative to the liquid outlet cavity 525. At the same time, since the volume of the liquid discharge cavity 524 decreases when the valve plug 53 moves toward the liquid inlet 521, the valve plug 53 moves toward the liquid inlet 521 under the pressure of the liquid to reduce the volume of the liquid discharge cavity 54 until the pressure in the liquid discharge cavity 524 is equal to the pressure in the liquid outlet cavity 532 or the valve plug 53 is blocked and stops moving. During the movement of the valve plug 53, the opening of the buffer hole 532 increases linearly, which can linearly increase the flow rate of the liquid when it flows through the buffer valve 5, thereby buffering the huge flow impact when the directional valve is opened. The valve plug 53 of the buffer valve 5 of the present invention is driven by the oil circuit pressure, and no additional control oil circuit is required, so the structure is simple and the manufacturing cost is low. In actual operation, the pressure of the liquid outlet cavity 532 of the buffer valve rises very quickly, and the valve plug 53 completes the movement in a very short time, which has little effect on the action speed of the oil circuit.

[0041] Specifically, Figure 5 As shown, the width of the buffer hole 532 gradually increases from the liquid inlet 521 to the liquid outlet 522, and the overall shape is "V". When the valve plug 53 moves toward the liquid inlet 521, since the overall shape of the buffer hole 532 is "V", the overlap area of ​​the buffer hole 532 and the middle cavity 523 increases linearly, that is, the opening of the buffer hole 532 increases linearly. In this embodiment, a plurality of the buffer holes 532 are evenly distributed along the circumference of the valve plug 53.

[0042] Specifically, Figure 6 As shown, the buffer portion 531 is a hollow cylinder, one end of which is open toward the liquid outlet, and the other end of which is provided with a partition 538; the partition 538 separates the valve plug 53 into a connecting portion 535 and the buffer portion 531; the connecting portion 535 is a hollow cylinder, one end of which is open toward the liquid inlet 521, and the other end of which is connected to the partition 538; a connecting hole 536 is provided on the connecting portion 535, and the connecting portion 535 is connected with the middle cavity 523 through the connecting hole 536.

[0043] Thus, the liquid flows into the valve chamber 52 from the liquid inlet 521 , then flows through the connecting portion 535 , the connecting hole 536 , the middle cavity 523 , the buffer hole 532 , the liquid outlet cavity 525 , and finally flows out of the valve chamber 52 from the liquid outlet 522 .

[0044] The communicating portion 535 is provided with a plurality of communicating holes 536 , and the plurality of communicating holes 536 are evenly distributed along the circumferential direction of the valve plug 53 .

[0045] In order to reduce the volume of the liquid discharge chamber 524 when the valve plug 53 moves toward the liquid inlet 521, a step 537 is provided on the outer surface of the valve plug 53, and the step 537 divides the valve plug 53 into a first valve plug section 533 and a second valve plug section 534;

[0046] The outer diameter of the first valve plug section 533 is greater than the outer diameter of the second valve plug section 534 , and the first valve plug section 533 is disposed close to the liquid outlet 522 , and the second valve plug section 534 is disposed close to the liquid inlet 521 ;

[0047] When the valve plug 53 is disposed in the valve chamber 52 , the step 537 is located in the drain chamber 524 .

[0048] Since the outer diameter of the first valve plug section 533 is greater than the outer diameter of the second valve plug section 534, the first valve plug section 533 and the second valve plug section 534 form an area difference, and when the valve plug 53 moves toward the liquid inlet 521, the volume of the liquid discharge chamber 524 is compressed. Since when the valve plug 53 is disposed in the valve chamber 52, the step 537 is located in the liquid discharge chamber 524, when the pressure of the liquid outlet chamber 525 rises, once the valve plug 53 is pushed, the volume of the liquid discharge chamber 524 begins to decrease, thereby promoting the pressure of the liquid outlet chamber 525 to push the valve plug 53 toward the liquid inlet 521 until the pressure in the liquid discharge chamber 524 is equal to the pressure in the liquid outlet chamber 525 or the valve plug 53 is blocked and stops moving.

[0049] Since the outer diameters of the first valve plug section 533 and the second valve plug section 534 are inconsistent, in order to make the valve plug 53 always close to the inner wall of the valve chamber 52 during operation, a first valve chamber section 526 is connected between the middle cavity 523 and the liquid discharge chamber 524, and the inner diameter of the first valve chamber section 526 matches the first valve plug section 533 of the valve plug 53, so that the first valve plug section 533 is close to the inner wall of the first valve chamber section 526; a second valve chamber section 527 is connected between the liquid inlet 521 and the liquid discharge chamber 524, and the inner diameter of the second valve chamber section 527 matches the second valve plug section 534 of the valve plug 53, so that the second valve plug section 534 is close to the inner wall of the second valve chamber section 527. In this way, it is possible to prevent the liquid from directly entering the liquid discharge chamber 524 from the gap between the valve plug 53 and the inner wall of the valve chamber 52, resulting in the inability to form a low pressure in the liquid discharge chamber 524, and further resulting in the inability of the valve plug 53 to be pushed.

[0050] Preferably, the first and second valve chamber sections 527 are both provided with grooves, in which dynamic sealing rings 55 are arranged, and the dynamic sealing ring 55 is tightly attached to the valve plug 53, further preventing liquid from entering the drainage cavity 524 through the gap between the valve plug 53 and the valve chamber 52.

[0051] An elastic element 54 is provided in the connecting portion 535, and the valve plug 53 is close to the liquid outlet 522 under the elastic force of the elastic element 54. By providing the elastic element 54, when the buffer valve is in a non-working state, the valve plug 53 is reset under the elastic action of the elastic element 54 and close to the liquid outlet 522, thereby providing sufficient space for the valve plug 53 to move toward the liquid outlet 522, so that the opening of the buffer hole 532 can change from the minimum to the maximum, so that the liquid flow is buffered. The elastic element 54 is preferably a spring. Preferably, when the buffer valve is in a non-working state, the flow area of ​​the buffer hole is less than 10% of the flow area when the buffer hole is fully opened.

[0052] In order to achieve the communication between the drainage chamber 524 and the outside of the valve body 51, the valve body 51 is provided with a drainage hole 56 extending in the radial direction of the valve body 51, one end of the drainage hole 56 is communicated with the drainage chamber 524, and the other end thereof is communicated with the outside of the valve body 51. By providing the drainage hole 56, the drainage chamber 524 is communicated with the outside of the valve body 51, ensuring that a pressure difference can be formed between the drainage chamber 524 and the liquid outlet chamber 525. The liquid in this embodiment can be hydraulic oil, and the drainage hole 56 can be communicated with an oil tank. Even if the liquid enters the drainage chamber 524 from the gap between the valve plug 53 and the valve body 52, the liquid can be discharged through the drainage hole 56, preventing the liquid from being retained in the drainage chamber 524, so that the pressure of the drainage chamber 524 increases.

[0053] The two ends of the buffer valve 5 are connected with an inlet flange 57 and an outlet flange 58 respectively; the inlet flange 57 is provided with a through hole facing the liquid inlet 521; the elastic element 54 is partially arranged in the connecting portion 535, and one end thereof is tightly against the partition 538, and the other end thereof is against the end face of the inlet flange 57; the outlet flange 58 is provided with a through hole facing the liquid outlet 522, and the first valve plug section 531 of the valve plug 53 is against the end face of the outlet flange 58. Static sealing rings 59 are respectively arranged between the inlet flange 57 and the valve body 51, and between the outlet flange 58 and the valve body 51.

[0054] Example 2

[0055] Embodiment 2 provides a large flow hydraulic system, such as Figure 7As shown, it includes the buffer valve 5, hydraulic cylinder 7 and cartridge valve 6 described in the above embodiment 1; the liquid inlet 521 of the buffer valve is connected to the cartridge valve 6, and the liquid outlet 522 of the buffer valve is connected to the hydraulic cylinder 7. When the cartridge valve 6 is opened, a large flow of liquid flows into the buffer valve 5, and the liquid flowing out of the buffer valve 5 flows into the hydraulic cylinder 7 linearly and incrementally, which reduces the impact of the large flow of liquid on the pipeline.

[0056] In the description of the present invention, it is necessary to understand that the terms "center", "left", "right", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0057] If the words "first", "second", etc. are used in this document to limit components, those skilled in the art should know that the use of "first" and "second" is only to facilitate the description of the present invention and simplify the description. Unless otherwise stated, the above words have no special meaning.

[0058] The present invention is not limited to the above-mentioned embodiments. If various changes or modifications to the present invention do not depart from the spirit and scope of the present invention, and if these changes and modifications fall within the scope of the claims and equivalent technologies of the present invention, the present invention is also intended to include these changes and modifications.

Claims

1. A buffer valve, characterized in that: include: A valve body having a valve chamber, two ends of which are respectively a liquid inlet and a liquid outlet; A valve plug is movably disposed in the valve chamber; the valve plug separates the valve chamber into a communicating chamber and a drain chamber that are sealed from each other; The valve plug is provided with a buffer portion, and the buffer portion divides the communication cavity into a middle cavity and a liquid outlet cavity; The buffer portion is provided with a buffer hole, and the middle cavity and the liquid outlet cavity are connected through the buffer hole; The liquid outlet, the liquid outlet cavity, the middle cavity and the liquid inlet are connected; the liquid discharge cavity is connected to the outside of the valve body; When the valve plug moves toward the liquid inlet, the opening of the buffer hole increases linearly, and the volume of the liquid drainage cavity decreases.

2. A buffer valve according to claim 1, characterized in that: The width of the buffer hole gradually increases along the direction from the liquid inlet to the liquid outlet, and is in a "V" shape as a whole.

3. A buffer valve according to claim 1, characterized in that: The buffer part is a hollow cylinder, one end of which is open toward the liquid outlet, and the other end of which is provided with a partition; The partition separates the valve plug into a communicating portion and a buffer portion; The connecting portion is a hollow cylinder, one end of which is open toward the liquid inlet and the other end of which is connected to the partition; The communicating portion is provided with a communicating hole, and the communicating portion is communicated with the middle cavity through the communicating hole.

4. A buffer valve according to claim 1, characterized in that: The outer surface of the valve plug is provided with a step, and the step divides the valve plug as a whole into a first valve plug section and a second valve plug section; The outer diameter of the first valve plug section is greater than the outer diameter of the second valve plug section, and the first valve plug section is arranged close to the liquid outlet, and the second valve plug section is arranged close to the liquid inlet; When the valve plug is disposed in the valve chamber, the step is located in the drain chamber.

5. A buffer valve according to claim 4, characterized in that: A first valve chamber section is connected between the communication chamber and the drain chamber, and the inner diameter of the first valve chamber section matches the first valve plug section of the valve plug, so that the first valve plug section is closely attached to the inner wall of the first valve chamber section; A second valve chamber section is connected between the liquid inlet and the liquid discharge cavity, and the inner diameter of the second valve chamber section matches the second valve plug section of the valve plug, so that the second valve plug section is closely attached to the inner wall of the second valve chamber section.

6. A buffer valve according to claim 5, characterized in that: The first and second valve chamber sections are both provided with grooves, and dynamic sealing rings are arranged in the grooves, and the dynamic sealing rings are in close contact with the valve plug.

7. A buffer valve according to claim 3, characterized in that: An elastic element is arranged in the communication portion, and the valve plug is close to the liquid outlet under the elastic force of the elastic element.

8. A buffer valve according to claim 1, characterized in that: The valve body is provided with a drainage hole extending in the radial direction of the valve body. One end of the drainage hole is communicated with the drainage cavity, and the other end of the drainage hole is communicated with the outside of the valve body.

9. A buffer valve according to claim 1, characterized in that: The two ends of the buffer valve are respectively connected with an inlet flange and an outlet flange; The inlet flange is provided with a through hole directly facing the liquid inlet; The outlet flange is provided with a through hole directly facing the liquid outlet, and the first valve plug section of the valve plug abuts against the end surface of the outlet flange.

10. A large flow hydraulic system, characterized in that: A buffer valve comprising any one of claims 1 to 9, and a hydraulic cylinder and a cartridge valve; The liquid inlet of the buffer valve is communicated with the cartridge valve, and the liquid outlet of the buffer valve is communicated with the hydraulic cylinder.

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