Three-stage pressure regulating overflow valve
By setting the first damping hole of the adjustment sleeve in the relief valve to adjust the oil flow, the problem of slow pressure establishment speed in the existing relief valve is solved, and the rapid response and good buffering effect of three-stage pressure regulation are achieved.
Patent Information
- Application Number
- CN202422554177.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-22
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-10-22
AI Technical Summary
When the existing relief valve is established, the first pressure is higher and the second pressure is established for a long time, so it cannot be established quickly.
A first damping hole of the adjustment sleeve is provided in the relief valve so that the oil pressure in the second chamber on the right side of the buffer piston is smaller than the oil pressure in the third chamber on the left side. The first damping hole realizes the throttling and pressure reduction of the oil, and regulates the oil flow to quickly establish pressure.
Lower first pressure and fast second and third pressure establishment are achieved, improving the buffering effect of the overflow valve.
Smart Images
Figure CN223165113U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of overflow valves, in particular to a three-stage pressure-regulating overflow valve. Background Art
[0002] At present, two pressure establishment processes are usually involved in an overflow valve, which can play a certain buffering role; however, as Figure 1 shown, since the flow of the oil between the inside of the valve core 2' and the buffer piston 1' is small, it is easy to cause a high back pressure of the valve core 2', so that the first established pressure is high, and the pressure of the oil at the liquid inlet 3' of the overflow valve needs to be large to instantaneously open the valve port 4'; moreover, since the oil pressures acting on the first wall 11' and the second wall 12' opposite to the buffer piston 1' are the same, the time required for the second pressure establishment is long, and the second pressure cannot be established quickly.
[0003] In view of the above problems, there is an urgent need for a three-stage pressure-regulating overflow valve to solve the above problems. Summary of the Utility Model
[0004] The purpose of the utility model is to provide a three-stage pressure-regulating overflow valve, in which a first damping hole is arranged in the adjusting sleeve, so that the oil pressure in the second chamber on the right side of the buffer piston is less than the oil pressure in the third chamber on the left side, so that the first established pressure can be made lower, and the time required for the second and third pressure establishments can be guaranteed to be shorter, and the pressure can be established quickly.
[0005] To achieve the above object, the utility model adopts the following technical solutions:
[0006] A three-stage pressure-regulating overflow valve, comprising:
[0007] A valve seat, on which a valve port, a liquid inlet and a liquid outlet are respectively arranged;
[0008] A valve core, which is slidably fitted in the valve seat to open or close the valve port, and a first chamber communicating with the liquid inlet is arranged in the valve core;
[0009] An adjusting assembly, comprising a buffer piston, an adjusting sleeve and a piston sleeve, the adjusting sleeve is arranged in the valve seat, at least part of the piston sleeve is arranged in the adjusting sleeve, the buffer piston is slidably fitted in the adjusting sleeve, a second chamber is formed between the buffer piston and the adjusting sleeve, a third chamber is formed between the buffer piston and the piston sleeve, both the second chamber and the third chamber communicate with the first chamber, and the adjusting sleeve is provided with a first damping hole, one end of the first damping hole communicates with the second chamber, the other end of the first damping hole can communicate with the liquid outlet, and the buffer piston can open or block the first damping hole.
[0010] As an alternative, the buffer piston is provided with a second damping hole which communicates with the second chamber and the first chamber respectively. Define the minimum aperture of the first damping hole as R1 and the minimum aperture of the second damping hole as R2, where R1 ≤ R2.
[0011] As an alternative, the minimum aperture R1 of the first damping hole is not greater than 0.2 mm.
[0012] As an alternative, the adjusting sleeve includes a first wall, and the buffer piston includes a second wall. The buffer piston has a first position and a second position. When the buffer piston is in the first position, a second chamber is formed between the first wall and the second wall; the first damping hole has a first opening on the first wall. When the buffer piston is in the second position, the second wall abuts against the first wall, causing the second wall to block the first opening.
[0013] As an alternative, the buffer piston further includes a third wall which is arranged opposite to the second wall; the piston sleeve includes a fourth wall. The third wall and the fourth wall can abut against each other or form a third chamber. A through hole is also provided on the buffer piston, which communicates the first chamber and the third chamber, and the minimum aperture of at least part of the second damping hole is smaller than the minimum aperture of the through hole.
[0014] As an alternative, the acting area of the hydraulic oil in the second chamber on the second wall is smaller than the acting area of the hydraulic oil in the third chamber on the third wall.
[0015] As an alternative, at least two of the first damping holes are circumferentially provided in the adjusting sleeve.
[0016] As an alternative, a third damping hole is provided in the valve core, which communicates the liquid inlet and the first chamber, and the aperture of at least part of the third damping hole is smaller than the diameter of the liquid inlet.
[0017] As an alternative, the three-stage pressure regulating overflow valve further includes:
[0018] An elastic member, sleeved on the valve core and located within the valve seat. One end of the elastic member abuts against the limiting platform of the valve core, and a fourth chamber is formed between the elastic member and the valve seat. The fourth chamber communicates the first damping hole and the liquid outlet;
[0019] The base is slidably sleeved on the valve core and is disposed opposite to the limiting platform. The other end of the elastic member abuts against the base, and the buffer piston can push the base along a first direction to compress the elastic member, so that the elastic member pushes the valve core to move along the first direction. The first direction is the axial direction of the valve core and is the direction close to the valve port.
[0020] The beneficial effects of the present utility model are as follows:
[0021] By forming a second chamber between the buffer piston and the adjusting sleeve, a third chamber between the buffer piston and the piston sleeve, and connecting the second chamber and the third chamber to the first chamber in the valve core respectively. At the same time, the adjusting sleeve is provided with a first damping hole. One end of the first damping hole is communicated with the second chamber, and the other end of the first damping hole can be communicated with the liquid outlet, and the buffer piston can open or block the first damping hole; when the first pressure is established, since the oil liquid at the liquid inlet has not had time to act on the buffer piston through the first chamber, at this time, the oil liquid pressure at the liquid inlet directly acts on the wall surface of the valve core close to the valve port to push the valve core to instantaneously open the valve port; while instantaneously opening the valve port, the oil liquid at the liquid inlet will flow into the second chamber and the third chamber respectively through the first chamber. Since the oil liquid in the second chamber can flow out to the liquid outlet through the first damping hole at this time, the oil liquid flow between the inside of the valve core and the buffer piston is enabled, so that the oil liquid pressure in the second chamber is reduced, the oil liquid pressure in the first chamber is reduced, so that the back pressure acting on the valve core is reduced, thereby enabling the oil liquid pressure at the liquid inlet to be relatively small to push the valve core to instantaneously open the valve port, realizing opening the valve with a relatively small pressure at the liquid inlet, and thus enabling the first established pressure to be relatively low.
[0022] After that, when the second pressure is established, due to the throttling and pressure reduction effect of the first damping hole, the oil liquid pressures in the first chamber and the second chamber are relatively small, while the oil liquid pressure in the third chamber is greater than the oil liquid pressure in the second chamber. Therefore, at this time, the buffer piston can quickly move in the direction close to the valve port to push the valve core to quickly move towards the valve port through the buffer piston, so that the valve core can re-seal the valve port, increasing the opening pressure at the liquid inlet, thereby enabling the second pressure to be quickly established and ensuring that the time required for establishing the second pressure is relatively short.
[0023] Then, during the third pressure build-up, due to the blocking effect of the adjusting sleeve on the buffer piston at this time, the buffer piston cannot continue to move towards the valve port. Meanwhile, the buffer piston blocks the first damping hole, preventing the oil from flowing through the first damping hole to the liquid outlet. At this time, the pressure of the oil in the first chamber will rise rapidly, causing the back pressure of the oil in the first chamber acting on the valve core to increase rapidly, further increasing the valve opening pressure at the liquid inlet, so that the third pressure can be quickly established, ensuring that the time required for the third pressure build-up is short. Through the above pressure build-up process, three-stage regulation of the oil pressure at the liquid inlet can be achieved, thus ensuring better buffer effect of the three-stage pressure regulating overflow valve. Description of the Drawings
[0024] Figure 1 is a cross-sectional view of an overflow valve in the prior art;
[0025] Figure 2 is a cross-sectional view of the three-stage pressure regulating overflow valve provided by the present invention;
[0026] Figure 3 is Figure 2 a partial enlarged structural view at C in
[0027] Description of the Reference Numerals:
[0028] 1'- buffer piston; 11'- first wall; 12'- second wall; 2'- valve core; 3'- liquid inlet; 4'- valve port;
[0029] 1 - valve seat; 11 - valve port; 12 - liquid inlet; 13 - liquid outlet; 14 - fourth chamber;
[0030] 2 - valve core; 21 - third damping hole; 22 - first chamber; 23 - limiting platform;
[0031] 31 - buffer piston; 311 - second wall; 312 - third wall; 313 - second damping hole; 314 - through hole; 315 - second chamber;
[0032] 32 - adjusting sleeve; 321 - first damping hole; 322 - first wall; 323 - fifth wall;
[0033] 33 - piston sleeve; 331 - fourth wall;
[0034] 4 - elastic member; 5 - base. Detailed Embodiments
[0035] All the features disclosed in this specification, or all the steps in any method or process disclosed, except for mutually exclusive features and / or steps, can be combined in any manner.
[0036] Any feature disclosed in this specification, unless specifically described, can be replaced by other equivalent or similar-purpose alternative features. That is, unless specifically described, each feature is only an example of a series of equivalent or similar features. Throughout the specification, the same reference numerals indicate the same elements.
[0037] To make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present utility model clearer, the technical solutions of the present utility model will be further described below with reference to the accompanying drawings and through specific embodiments.
[0038] In this embodiment, a three-stage pressure-regulating overflow valve is proposed. This three-stage pressure-regulating overflow valve can perform three pressure regulations, and the first pressure established is relatively small. At the same time, it can quickly establish the second and third pressures, ensuring that the time required to establish the second and third pressures is relatively short, resulting in a better buffering effect of the three-stage pressure-regulating overflow valve.
[0039] Specifically, as Figure 2 and Figure 3 shown, the three-stage pressure-regulating overflow valve includes a valve seat 1, a valve core 2, and an adjustment assembly. Among them, a valve port 11, a liquid inlet 12, and a liquid outlet 13 are respectively provided on the valve seat 1. The valve core 2 is slidably fitted inside the valve seat 1 to open or close the valve port 11, and a first chamber 22 communicating with the liquid inlet 12 is provided inside the valve core 2. The adjustment assembly includes a buffer piston 31, an adjustment sleeve 32, and a piston sleeve 33. The adjustment sleeve 32 is provided inside the valve seat 1. At least part of the piston sleeve 33 is provided inside the adjustment sleeve 32. The buffer piston 31 is slidably fitted inside the adjustment sleeve 32. A second chamber 315 is formed between the buffer piston 31 and the adjustment sleeve 32. A third chamber is formed between the buffer piston 31 and the piston sleeve 33. Both the second chamber 315 and the third chamber are connected to the first chamber 22. And a first damping hole 321 is provided on the adjustment sleeve 32. One end of the first damping hole 321 communicates with the second chamber 315, and the other end of the first damping hole 321 can communicate with the liquid outlet 13, and the buffer piston 31 can open or block the first damping hole 321.
[0040] Compared with the prior art, in this embodiment of the three-stage pressure-regulating overflow valve, a first damping hole 321 is provided on the adjustment sleeve 32, and one end of the first damping hole 321 communicates with the second chamber 315, and the other end of the first damping hole 321 can communicate with the liquid outlet 13, and the buffer piston 31 can open or block the first damping hole 321. As a result, the first damping hole 321 can provide a throttling and pressure-reducing effect on the oil in the first chamber 22, and can realize three regulations of the oil pressure at the liquid inlet 12, thereby ensuring the fast response and good buffering effect of the three-stage pressure-regulating overflow valve.
[0041] First, during the first pressure build-up, since the hydraulic fluid at the inlet port 12 has not yet had time to act on the buffer piston 31 through the first chamber 22, at this time, the hydraulic fluid pressure at the inlet port 12 directly acts on the wall surface of the valve core 2 near the valve port 11 to push the valve core 2 to move in the second direction to instantaneously open the valve port 11. While instantaneously opening the valve port 11, the hydraulic fluid at the inlet port 12 will flow into the second chamber 315 and the third chamber respectively through the first chamber 22. Since the hydraulic fluid in the second chamber 315 can flow out to the outlet port 13 through the first damping hole 321 and return to the fuel tank through the outlet port 13, the hydraulic fluid between the inside of the valve core 2 and the buffer piston 31 starts to flow, reducing the hydraulic fluid pressure in the second chamber 315, reducing the hydraulic fluid pressure in the first chamber 22, and reducing the back pressure acting on the valve core 2. As a result, a relatively small hydraulic fluid pressure at the inlet port 12 can push the valve core 2 to instantaneously open the valve port 11, achieving a low-pressure valve opening at the inlet port 12 and thus resulting in a relatively low first pressure build-up. Here, the second direction is the axial direction of the valve core 2 and away from the valve port 11, and the second direction is specifically as shown by the arrow B in Figure 2 as shown.
[0042] After that, during the second pressure build-up, due to the throttling and pressure-reducing effect of the first damping hole 321, the hydraulic fluid pressures in the first chamber 22 and the second chamber 315 are relatively small, while the hydraulic fluid pressure in the third chamber is greater than the hydraulic fluid pressure in the second chamber 315. Therefore, at this time, the buffer piston 31 can quickly move in the first direction to push the valve core 2 quickly towards the valve port 11 through the buffer piston 31, enabling the valve core 2 to re-close the valve port 11, increasing the valve opening pressure at the inlet port 12, and thus quickly building the second pressure, ensuring that the time required for the second pressure build-up is relatively short. Here, the first direction is the axial direction of the valve core 2 and towards the valve port 11, the first direction is opposite to the second direction, and the first direction is specifically as shown by the arrow A in Figure 2 as shown.
[0043] Then, during the third pressure build-up, due to the blocking effect of the adjusting sleeve 32 on the buffer piston 31 at this time, the buffer piston 31 cannot continue to move in the first direction. At the same time, the buffer piston 31 blocks the first damping hole 321, preventing the hydraulic fluid from flowing through the first damping hole 321 to the outlet port 13. At this time, the pressure of the hydraulic fluid in the first chamber 22 will quickly increase, causing the back pressure of the hydraulic fluid in the first chamber 22 acting on the valve core 2 to quickly increase, increasing the valve opening pressure at the inlet port 12, and thus quickly building the third pressure, ensuring that the time required for the third pressure build-up is relatively short.
[0044] By performing simulations on two cases, one without the first damping hole 321 and the other with the first damping hole 321, it can be obtained that the overflow valve in the prior art without the first damping hole 321 has two pressure build-up processes, and the pressure build-up process is relatively slow; while in the present application, after setting the first damping hole 321, the overflow valve has three pressure build-up processes, and the first pressure built is lower, and the second and third pressure build-ups are faster.
[0045] It should be noted that the back pressure of the spool 2 mentioned above specifically refers to the pressure of the oil in the first chamber 22 acting on the wall surface of the spool 2 within the first chamber 22 and close to the valve port 11, so that the back pressure of the spool 2 directly acts on the valve port 11.
[0046] Furthermore, as Figure 3 shown, the buffer piston 31 is provided with a second damping hole 313, and the second damping hole 313 is respectively communicated with the second chamber 315 and the first chamber 22. Define the minimum aperture of the first damping hole 321 as R1, and the minimum aperture of the second damping hole 313 as R2, and R1 ≤ R2, so as to ensure that the throttling effect of the first damping hole 321 is more obvious, making the first pressure built lower; and it can keep the pressure in the first chamber 22, so as to ensure that the buffer piston 31 is pushed under the pressure difference, ensuring the normal use performance of the overflow valve. Specifically, the minimum aperture R1 of the first damping hole 321 is not greater than 0.2 mm, so that the minimum aperture R1 of the first damping hole 321 is not too large, thus ensuring a better throttling and pressure reduction effect for the first damping hole 321 with a smaller aperture. Here, there is no specific limitation on the minimum aperture R1 of the first damping hole 321, as long as it does not exceed 0.2 mm.
[0047] Figure 2 Figure 3 Specifically, as Figure 2 and Figure 3 shown, the adjusting sleeve 32 includes a first wall 322 and a fifth wall 323 arranged opposite to each other. The first damping hole 321 has a first opening on the first wall 322, and the first damping hole 321 has a second opening on the fifth wall 323. The first opening is communicated with the second opening, and the second opening is communicated with the liquid outlet 13; and the buffer piston 31 includes a second wall 311, and along the axial direction of the spool 2, the first wall 322 is arranged opposite to the second wall 311.
[0048] Specifically, the buffer piston 31 has a first position and a second position; when the buffer piston 31 is in the first position, the second chamber 315 is formed between the first wall 322 and the second wall 311, and the buffer piston 31 abuts against the piston sleeve 33; when the buffer piston 31 is in the second position, the second wall 311 abuts against the first wall 322 to block the first opening by the second wall 311, and a third chamber is formed between the buffer piston 31 and the piston sleeve 33; that is to say, the first position is the position where the first damping hole 321 is opened, and the second position is the position where the first damping hole 321 is blocked.
[0049] Figure 2 Figure 3 Further, as Figure 2 and Figure 3 shown, the buffer piston 31 further includes a third wall 312, and the third wall 312 is arranged opposite to the second wall 311; the piston sleeve 33 includes a fourth wall 331, and the third wall 312 and the fourth wall 331 can abut against each other or form a third chamber. A through hole 314 is further provided on the buffer piston 31, and the through hole 314 communicates the first chamber 22 with the third chamber, and the minimum aperture of at least a part of the second damping hole 313 is smaller than the minimum aperture of the through hole 314 to ensure the throttling and pressure reducing effect of the second damping hole 313.
[0050] Specifically, the acting area of the hydraulic oil in the second chamber 315 on the second wall 311 is smaller than the acting area of the hydraulic oil in the third chamber on the third wall 312, and during the second pressure establishment, due to the throttling and pressure reducing effect of the first damping hole 321, the hydraulic oil pressure in the third chamber is greater than the hydraulic oil pressure in the second chamber 315. Therefore, at this time, it can be ensured that the hydraulic oil pressure in the third chamber is much greater than the hydraulic oil pressure in the second chamber 315, so that the buffer piston 31 can move along the first direction more quickly to push the valve core 2 to move towards the valve port 11 more quickly through the buffer piston 31.
[0051] Further, as Figure 2 and Figure 3As shown, at least two first damping holes 321 are evenly arranged circumferentially inside the adjusting sleeve 32, so as to ensure the balance of the oil pressure in the second chamber 315 through the at least two evenly arranged first damping holes 321, and avoid deviation and imbalance of the oil pressure in the second chamber 315. In this embodiment, two first damping holes 321 are evenly arranged circumferentially inside the adjusting sleeve 32. In other embodiments, three first damping holes 321 can also be evenly arranged circumferentially inside the adjusting sleeve 32, so as to further ensure the throttling and pressure reduction effect on the first chamber 22 through the three first damping holes 321, making the pressure established for the first time smaller, and the time required for the establishment of the second pressure and the third pressure shorter. Here, the number of the first damping holes 321 is not limited, as long as it can ensure that each first damping hole 321 is evenly distributed and is connected to the second chamber 315.
[0052] Further, as Figure 2 and Figure 3 shown, a third damping hole 21 is arranged inside the valve core 2. The third damping hole 21 communicates the liquid inlet 12 with the first chamber 22, and at least part of the aperture of the third damping hole 21 is smaller than the aperture of the liquid inlet 12, so as to ensure the throttling and pressure reduction effect of the third damping hole 21.
[0053] Specifically, as Figure 2 shown, the three-stage pressure regulating overflow valve further includes an elastic member 4 and a base 5; wherein, the elastic member 4 is sleeved on the valve core 2 and is located inside the valve seat 1. One end of the elastic member 4 abuts against the limiting platform 23 of the valve core 2, and a fourth chamber 14 is formed between the elastic member 4 and the valve seat 1. The fourth chamber 14 communicates the second opening of the first damping hole 321 with the liquid outlet 13; the base 5 is slidably sleeved on the valve core 2 and is arranged opposite to the limiting platform 23. The other end of the elastic member 4 abuts against the base 5, and the buffer piston 31 can push the base 5 along the first direction to compress the elastic member 4, so that the elastic member 4 pushes the valve core 2 to move along the first direction. In this embodiment, the elastic member 4 can specifically be a spring.
[0054] The specific working process of the three-stage pressure regulating overflow valve in this embodiment is as follows:
[0055] First, the oil enters from the liquid inlet 12, and the oil pressure at the liquid inlet 12 directly acts on the wall surface of the valve core 2 close to the valve port 11 to instantaneously push the valve core 2 to open the valve port 11 along the second direction; while instantaneously opening the valve port 11, the oil at the liquid inlet 12 enters the first chamber 22 through the third damping hole 21, and then enters the second chamber 315 through the first chamber 22 and the second damping hole 313, so that the oil in the second chamber 315 acts on the second wall 311 of the buffer piston 31; at the same time, the oil in the first chamber 22 enters the third chamber through the through hole 314, so that the oil in the third chamber acts on the third wall 312 of the buffer piston 31.
[0056] Meanwhile, the oil in the second chamber 315 can flow out through the first damping hole 321 to the liquid outlet 13, and then flow back to the fuel tank through the liquid outlet 13, enabling the oil to flow between the inside of the valve core 2 and the buffer piston 31, reducing the oil pressure in the second chamber 315, thereby reducing the oil pressure in the first chamber 22 and decreasing the back pressure acting on the valve core 2. Since the oil pressure at the liquid inlet 12 needs to overcome the elastic force of the elastic member 4 and the back pressure of the valve core 2, and at this time the back pressure of the valve core 2 decreases, the oil pressure at the liquid inlet 12 can be relatively small to instantaneously push the valve core 2 to open the valve port 11, achieving valve opening at a relatively low pressure at the liquid inlet 12, and thus resulting in a relatively low first established pressure.
[0057] Then, due to the decrease in the oil pressure in the second chamber 315, the acting force of the oil in the second chamber 315 on the second wall 311 is less than the acting force of the oil in the third chamber on the third wall 312; moreover, since the acting area of the oil in the second chamber 315 on the second wall 311 is smaller than the acting area of the oil in the third chamber on the third wall 312; therefore, the buffer piston 31 moves in the first direction under the action of the oil on the two walls, enabling the buffer piston 31 to push against the base 5 in the first direction to further compress the elastic member 4, causing the elastic member 4 to push the valve core 2 to move in the first direction, increasing the acting force of the elastic member 4 on the valve core 2. Since the oil pressure at the liquid inlet 12 needs to overcome the elastic force of the elastic member 4 and the back pressure of the valve core 2, and at this time the elastic force of the elastic member 4 increases, the valve opening pressure of the oil at the liquid inlet 12 can be increased; until the second wall 311 of the buffer piston 31 abuts against the first wall 322 of the adjusting sleeve 32 to block the first damping hole 321. At this time, the second pressure is stably established.
[0058] Subsequently, due to the blocking effect of the first wall 322 of the adjusting sleeve 32 on the second wall 311 of the buffer piston 31 at this time, the buffer piston 31 cannot continue to move in the first direction; and at this time, the buffer piston 31 blocks the first damping hole 321, preventing the oil from flowing through the first damping hole 321 to the liquid outlet 13; therefore, at this time, the pressure of the oil in the first chamber 22 will rapidly increase, causing the back pressure of the oil in the first chamber 22 acting on the valve core 2 to rapidly increase; since the oil pressure at the liquid inlet 12 needs to overcome the elastic force of the elastic member 4 and the back pressure of the valve core 2, and at this time the back pressure of the valve core 2 increases, the valve opening pressure of the oil at the liquid inlet 12 can be further increased, thereby rapidly establishing the third pressure.
[0059] Finally, when the oil pressure at the liquid inlet 12 rises to be able to overcome the elastic force of the elastic member 4 and the back pressure of the valve core 2, the oil pressure at the liquid inlet 12 pushes the valve core 2 to move in the second direction, causing the valve core 2 to reopen the valve port 11, thereby opening the overflow.
[0060] In the three-stage pressure-regulating overflow valve in this embodiment, by providing the first damping hole 321, the throttling and pressure-reducing effects of the second damping hole 313 and the third damping hole 21 during the pressure establishment process can be ensured, ensuring that the primary pressure established is relatively low and the buffering effect is good. At the same time, through the throttling and pressure-reducing effect of the first damping hole 321, the hydraulic forces acting on the second wall 311 and the third wall 312 of the buffer piston 31 are not equal, so that the buffer piston 31 can be quickly pushed to move in the first direction by the pressure difference between the second wall 311 and the third wall 312 of the buffer piston 31 to compress the elastic member 4, thereby quickly establishing the second pressure and shortening the time for establishing the second pressure. Moreover, by blocking the first damping hole 321 with the second wall 311 of the buffer piston 31, the back pressure of the spool 2 can be quickly increased, thereby quickly establishing the third pressure and shortening the time for establishing the third pressure.
[0061] The above content is only the preferred embodiment of the present invention. For those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. The content of this specification should not be construed as a limitation to the present invention.
Claims
1. Three-stage pressure-regulating overflow valve, characterized in that, Comprising: A valve seat (1) provided with a valve port (11), a liquid inlet port (12) and a liquid outlet port (13) respectively thereon; A valve core (2) slidably fitted within the valve seat (1) to open or close the valve port (11), and a first chamber (22) communicating with the liquid inlet port (12) is provided within the valve core (2); An adjusting assembly, including a buffer piston (31), an adjusting sleeve (32) and a piston sleeve (33). The adjusting sleeve (32) is disposed within the valve seat (1), at least a part of the piston sleeve (33) is disposed within the adjusting sleeve (32), the buffer piston (31) is slidably fitted within the adjusting sleeve (32), a second chamber (315) is formed between the buffer piston (31) and the adjusting sleeve (32), a third chamber is formed between the buffer piston (31) and the piston sleeve (33), both the second chamber (315) and the third chamber communicate with the first chamber (22), and the adjusting sleeve (32) is provided with a first damping hole (321). One end of the first damping hole (321) communicates with the second chamber (315), and the other end of the first damping hole (321) can communicate with the liquid outlet port (13). The buffer piston (31) can open or block the first damping hole (321).
2. The three-stage pressure-regulating overflow valve according to claim 1, wherein The buffer piston (31) is provided with a second damping hole (313) which communicates with both the second chamber (315) and the first chamber (22). Define the minimum aperture of the first damping hole (321) as R1, and the minimum aperture of the second damping hole (313) as R2, where R1 ≤ R2.
3. The three-stage pressure regulating overflow valve according to claim 2, wherein The minimum aperture R1 of the first damping hole (321) is not greater than 0.2 mm.
4. The three-stage pressure regulating overflow valve according to claim 2, wherein The adjusting sleeve (32) includes a first wall (322), and the buffer piston (31) includes a second wall (311). The buffer piston (31) has a first position and a second position. When the buffer piston (31) is in the first position, the second chamber (315) is formed between the first wall (322) and the second wall (311); the first damping hole (321) has a first opening in the first wall (322). When the buffer piston (31) is in the second position, the second wall (311) abuts against the first wall (322) to block the first opening.
5. The three-stage pressure regulating overflow valve according to claim 4, characterized in that, The buffer piston (31) further includes a third wall (312) disposed opposite to the second wall (311); the piston sleeve (33) includes a fourth wall (331). The third wall (312) and the fourth wall (331) can abut against each other or form the third chamber. A through hole (314) is further provided on the buffer piston (31), the through hole (314) communicates the first chamber (22) with the third chamber, and the minimum aperture of at least a part of the second damping hole (313) is smaller than the minimum aperture of the through hole (314).
6. The three-stage pressure regulating overflow valve according to claim 5, characterized in that, The acting area of the hydraulic oil in the second chamber (315) on the second wall (311) is smaller than the acting area of the hydraulic oil in the third chamber on the third wall (312).
7. The three-stage pressure regulating overflow valve according to any one of claims 1-6, characterized in that, At least two of the first damping holes (321) are circumferentially and evenly arranged inside the adjusting sleeve (32).
8. The three-stage pressure-regulating overflow valve according to any one of claims 1-6, characterized in that, A third damping hole (21) is arranged inside the valve core (2). The third damping hole (21) communicates the liquid inlet (12) with the first chamber (22), and the aperture of at least part of the third damping hole (21) is smaller than the diameter of the liquid inlet (12).
9. The three-stage pressure-regulating overflow valve according to any one of claims 1-6, characterized in that, The three-stage pressure regulating overflow valve further includes: An elastic member (4) sleeved on the valve core (2) and located inside the valve seat (1). One end of the elastic member (4) abuts against the limiting platform (23) of the valve core (2), and a fourth chamber (14) is formed between the elastic member (4) and the valve seat (1). The fourth chamber (14) communicates the first damping hole (321) with the liquid outlet (13); A base (5) slidably sleeved on the valve core (2) and arranged opposite to the limiting platform (23). The other end of the elastic member (4) abuts against the base (5), and the buffer piston (31) can push the base (5) along a first direction to compress the elastic member (4), so that the elastic member (4) pushes the valve core (2) to move along the first direction. The first direction is the axial direction of the valve core (2) and is the direction close to the valve port (11).