Pressure-limited stable hydraulic control one-way valve

Abstract

The present application relates to a kind of hydraulic support pressure-limiting stable liquid control check valve.The technical problems to be solved by the present application are to provide a kind of hydraulic support pressure-limiting stable liquid control check valve.The technical scheme adopted by the present application: including valve body and liquid control valve core assembly, pressure-limiting valve core assembly, the pressure-limiting valve core assembly includes pressure-limiting valve seat, pressure regulating valve sleeve, pressure-limiting valve core, pressure-limiting spring, pressure regulating valve seat, pressure regulating valve core, pressure regulating spring and pressure regulating screw, pressure-limiting valve seat is equipped with pressure-limiting cavity, the front end of the pressure-limiting cavity is equipped with pressure-limiting valve seat stop, the middle part of the pressure-limiting cavity is equipped with main drain hole, pressure-limiting valve core is equipped with pressure-limiting hole;The pressure regulating cavity is equipped in the pressure regulating valve sleeve, and the pressure regulating valve seat includes valve seat sleeve joint and valve seat drainage part.The present application has the advantages that: make the upper back liquid unobstructed, work normally;The design of locking member makes that after pressure regulation, it will not appear loose due to long time use, and the pressure generates greater error, and the pressure-limiting stability is higher, and the safety is higher.

Description

Technical Field

[0001] The invention relates to a hydraulically controlled one-way valve, in particular to a hydraulically controlled one-way valve with stable pressure limit used for a hydraulic support. Background Art

[0002] In recent years, the coal industry has responded to the national call for high production and high efficiency, and fully mechanized mining equipment has developed rapidly. In the past few years, the demand was to increase mechanization and automation in coal mining, but now it has evolved to require less-manned, unmanned, and intelligent operations. Although my country's equipment manufacturing is already at the forefront of the world, this rapid development has exposed some design issues that have not kept pace. For example, the introduction of high-resistance, high-mining-height hydraulic supports has greatly improved coal mining efficiency and resource utilization. However, after a period of use, this equipment often suffers from cylinder expansion in the column jacks with large bore-to-bore ratios, impacting safety and production. Analysis revealed that the main cause of column expansion is a tight fit within the two-position, three-way main valve core of the electro-hydraulic control reversing valve assembly, making it difficult to reset. This results in poor fluid return to the upper chamber of the column during the column raising process, resulting in pressure buildup and expansion. This problem is very rare in hydraulic supports that are not large-scale and controlled by electro-hydraulic control reversing valves. It is a new and developing issue, so we need to find a solution as soon as possible. While resolving the expansion issue, we must also maintain stability and minimize any subsequent complications. Summary of the Invention

[0003] In order to solve the above problems, the technical problem to be solved by the present invention is to provide a hydraulically controlled one-way valve with stable pressure limitation for a hydraulic support.

[0004] The technical solution adopted by the stable pressure-limiting hydraulically controlled one-way valve of the present invention: comprises a valve body and a hydraulically controlled valve core assembly, characterized in that it also comprises a pressure-limiting valve core assembly, the pressure-limiting valve core assembly comprises a pressure-limiting valve seat, a pressure-regulating valve sleeve screwed together with the pressure-limiting valve seat, a pressure-limiting valve core, a pressure-limiting spring, a pressure-regulating valve seat, a pressure-regulating valve core, a pressure-regulating spring and a pressure-regulating screw, a pressure-limiting cavity for inserting the pressure-limiting valve core is provided in the pressure-limiting valve seat, a pressure-limiting valve seat stop portion is provided at the front end of the pressure-limiting cavity to form a sealing pair with the pressure-limiting valve core, a main drain hole is provided in the middle of the pressure-limiting cavity, one end of the pressure-limiting spring abuts against the pressure-limiting valve core and the other end abuts against the pressure-regulating valve seat, and a pressure-limiting hole is provided on the pressure-limiting valve core;

[0005] The pressure regulating valve sleeve is provided with a pressure regulating cavity, the pressure regulating valve seat comprises a valve seat sleeve joint part and a valve seat drainage part, the valve seat sleeve joint part is provided with a pressure regulating hole communicated with the pressure limiting hole, the valve seat drainage part is provided with a secondary drainage hole communicated with the pressure regulating hole perpendicularly, the pressure regulating cavity is provided with a pressure regulating valve seat positioning groove corresponding to the valve seat sleeve joint part and a valve sleeve drainage hole communicated with the secondary drainage hole, the pressure regulating valve seat is provided with a valve core action cavity for placing the pressure regulating valve core, the valve core action cavity is provided with a pressure regulating valve seat stop part forming a sealing pair with the pressure regulating valve core at the front end, one end of the pressure regulating spring is abutted against the pressure regulating valve core and the other end is abutted against the pressure regulating screw, and the pressure regulating screw is screwed in the end part of the pressure regulating valve sleeve.

[0006] The pressure regulating valve sleeve is provided with a valve sleeve outer thread screwed with the valve body and a valve sleeve tightening head facilitating the tightening of the valve sleeve outer thread.

[0007] The locking member comprises a locking member end plate, the locking member end plate is provided with a locking member top column abutting against the outside of the pressure regulating screw, and the locking member top column is provided with a locking member through hole facilitating the adjustment of the pressure regulating screw.

[0008] The locking member is provided with a locking member side positioning plate and a locking member upper positioning plate outside the locking member top column, the locking member side positioning plate is provided with a locking member side fixed hole, and the locking member upper positioning plate is provided with a locking member upper fixed hole.

[0009] The valve body is provided with a pressure limiting valve core assembly installation cavity for placing the pressure limiting valve core assembly, the valve body is provided with a locking member side insertion groove corresponding to the locking member side positioning plate, a locking member upper insertion groove corresponding to the locking member upper positioning plate, a side fixed hole adjustment groove communicated with the locking member side insertion groove and used for adjusting the locking member side fixed hole, and an upper fixed hole adjustment groove communicated with the locking member upper insertion groove and used for adjusting the locking member upper fixed hole outside the pressure limiting valve core assembly installation cavity.

[0010] The valve sleeve tightening head is a regular hexagon structure, and the locking member end plate is further provided with a tightening head limiting groove for locking the valve sleeve tightening head outside the locking member top column.

[0011] The diameter of the pressure limiting hole is smaller than the diameter of the pressure regulating hole.

[0012] The main drainage hole is arranged at the middle part of the pressure limiting cavity at intervals along a circular arc, and the valve seat drainage part is provided with the secondary drainage hole at intervals along a circular arc.

[0013] The pressure regulating valve core comprises a pressure regulating valve core sealing part constituting a conical surface seal with the pressure regulating valve seat blocking part, a pressure regulating valve core positioning part corresponding to the valve seat drainage part, and a pressure regulating spring first positioning column for positioning the end part of the pressure regulating spring, and the pressure regulating screw is provided with a pressure regulating spring second positioning column for positioning the end part of the pressure regulating spring.

[0014] The hydraulic control valve core assembly comprises a hydraulic control end sleeve, an end sleeve joint, a hydraulic control valve seat and a hydraulic control valve sleeve connected in sequence, a hydraulic control jack, a jack spring, a hydraulic control valve core and a valve core spring arranged in the end sleeve joint and the hydraulic control valve seat, the hydraulic control end sleeve is provided with an upper cavity inflow port communicated with the upper cavity of the column jack, and the valve body is provided with a valve body transfer port, one end of the valve body transfer port is communicated with the upper cavity inflow port, and the other end is communicated with the pressure limiting hole.

[0015] The hydraulic control end sleeve is provided with a hydraulic control end sleeve partition plate and a jack action cavity, the hydraulic control end sleeve partition plate is provided with an end sleeve inflow hole, the jack spring is sleeved on the hydraulic control jack, one end of the jack spring abuts against the end part of the hydraulic control jack, and the other end abuts against the hydraulic control valve seat, the hydraulic control valve seat is provided with a hydraulic control liquid supply port, the hydraulic control valve core is in sealed pair cooperation with the hydraulic control valve seat, one end of the valve core spring abuts against the hydraulic control valve core, and the other end abuts against the hydraulic control valve sleeve, and the hydraulic control valve sleeve is provided with a lower cavity outflow port communicated with the lower cavity of the column jack.

[0016] The hydraulic control one-way valve with pressure limiting stability has the following advantages: 1 when the upper cavity expands the cylinder and the liquid return is not smooth, the hydraulic control one-way valve module with the pressure limiting valve core assembly can effectively release the pressure of the upper cavity without affecting the work of the two-position three-way main valve core, so that the liquid return is smooth, and the use effect is good; 2 the pressure regulating screw can flexibly adjust the pressure of the upper cavity according to the needs, and the design of the locking part makes the pressure adjustment good, so that the pressure does not have a large error due to loosening after long-term use, so as to avoid the problem of upper cavity expansion cylinder again, and the pressure limiting stability and safety are higher. BRIEF DESCRIPTION OF DRAWINGS

[0017] The application will be further described in detail below in combination with the drawings and specific embodiments.

[0018] Figure 1 is an exploded view of the hydraulic control one-way valve with pressure limiting stability;

[0019] Figure 2 is an exploded view of the pressure limiting valve core assembly;

[0020] Figure 3 is a structural schematic view of the pressure limiting valve seat;

[0021] Figure 4 is a structural schematic view of the pressure limiting valve core;

[0022] Figure 5 is a structural schematic diagram of a pressure regulating valve seat of the present application;

[0023] Figure 6 is a structural schematic diagram of a pressure regulating valve sleeve of the present application;

[0024] Figure 7 is another structural schematic diagram of a pressure regulating valve seat of the present application;

[0025] Figure 8 is another structural schematic diagram of a pressure regulating valve sleeve of the present application;

[0026] Figure 9 is a structural schematic diagram of a locking member of the present application;

[0027] Figure 10 is a structural schematic diagram of a valve body of the present application;

[0028] Figure 11 is a structural schematic diagram of a pressure regulating valve spool of the present application;

[0029] Figure 12 is a structural schematic diagram of a pressure regulating screw of the present application;

[0030] Figure 13 is an exploded view of a hydraulic control valve spool assembly of the present application;

[0031] Figure 14 is a structural schematic diagram of an end sleeve joint of the present application;

[0032] Figure 15 is a structural schematic diagram of a hydraulic control valve seat of the present application;

[0033] Figure 16 is a structural schematic diagram of a hydraulic control valve sleeve of the present application;

[0034] Figure 17 is a semi-sectional view of a hydraulic control one-way valve with pressure limiting and stabilization of the present application;

[0035] Figure 18 is a sectional view of a pressure limiting valve spool assembly in an inoperative state of the present application;

[0036] Figure 19 is a sectional view of a pressure limiting valve spool assembly in a pressure regulating valve spool open state of the present application;

[0037] Figure 20 is a sectional view of a pressure limiting valve spool assembly in a pressure regulating valve spool open state and a pressure limiting valve spool following open state of the present application;

[0038] Figure 21 is a sectional view of a pressure limiting valve spool assembly in a pressure regulating valve spool closed state and a pressure limiting valve spool waiting to close state of the present application. DETAILED DESCRIPTION

[0039] As Figures 1-17 The pressure-limiting stable hydraulic control one-way valve relates to the technical field of hydraulic control valve, and discloses a pressure-limiting stable hydraulic control one-way valve, which comprises a valve body 1, a hydraulic control valve core assembly 2 and a pressure-limiting valve core assembly 3, wherein the pressure-limiting valve core assembly 3 comprises a pressure-limiting valve seat 10, a pressure-regulating valve sleeve 11 screwed with the pressure-limiting valve seat 10, a pressure-limiting valve core 12, a pressure-limiting spring 13, a pressure-regulating valve seat 14, a pressure-regulating valve core 15, a pressure-regulating spring 16 and a pressure-regulating screw 17, the pressure-limiting valve seat 10 is internally provided with a pressure-limiting cavity 20 for placing the pressure-limiting valve core 12, the front end of the pressure-limiting cavity 20 is provided with a pressure-limiting valve seat stop portion 21 matched with the pressure-limiting valve core 12 to form a sealing pair, the middle part of the pressure-limiting cavity 20 is provided with a main liquid discharge hole 22, one end of the pressure-limiting spring 13 is abutted against the pressure-limiting valve core 12 and the other end of the pressure-limiting spring 13 is abutted against the pressure-regulating valve seat 14, and the pressure-limiting valve core 12 is provided with a pressure-limiting hole 24, the pressure-regulating valve sleeve 11 is internally provided with a pressure-regulating cavity 26, the pressure-regulating valve seat 14 comprises a valve seat sleeve joint portion 27 and a valve seat water discharge portion 28, the valve seat sleeve joint portion 27 is provided with a pressure-regulating hole 29 communicated with the pressure-limiting hole 24, the valve seat water discharge portion 28 is provided with a secondary liquid discharge hole 30 vertically communicated with the pressure-regulating hole 29, the pressure-regulating cavity 26 is internally provided with a pressure-regulating valve seat positioning groove 32 corresponding to the valve seat sleeve joint portion 27 and a valve sleeve liquid discharge hole 33 communicated with the secondary liquid discharge hole 30, the pressure-regulating valve seat 14 is internally provided with a valve core action cavity 35 for placing the pressure-regulating valve core 15, the front end of the valve core action cavity 35 is provided with a pressure-regulating valve seat stop portion 31 matched with the pressure-regulating valve core 15 to form a sealing pair, one end of the pressure-regulating spring 16 is abutted against the pressure-regulating valve core 15 and the other end of the pressure-regulating spring 16 is abutted against the pressure-regulating screw 17, and the pressure-regulating screw 17 is screwed at the end of the pressure-regulating valve sleeve 11, when the cylinder is expanded and the liquid return is not smooth, the pressure-limiting stable hydraulic control one-way valve module with the pressure-limiting valve core assembly is introduced to effectively release the pressure of the upper cavity without affecting the work of the two-position three-way main valve core, so that the liquid return is smooth, the use effect is good, the processing is convenient, the installation is convenient and the maintenance is convenient.

[0040] The pressure-regulating valve sleeve 11 is provided with a valve sleeve external thread 38 threadedly connected with the valve body 1 and a valve sleeve tightening head 39 facilitating the tightening of the valve sleeve external thread 38, the pressure-regulating screw 17 is fixed in the valve sleeve tightening head 39, the tightening of the pressure-regulating valve sleeve is facilitated, the operation is more convenient, the pressure-regulating screw 17 is used for adjusting the control pressure of the small flow pilot liquid, and the pressure-limiting pressure required by each working condition can be met.

[0041] The pressure-limiting stable hydraulic control one-way valve further comprises a locking member 4, the locking member 4 comprises a locking member end plate 40, the locking member end plate 40 is provided with a locking member top column 41 abutting against the outside of the pressure-regulating screw 17, the locking member top column 41 is internally provided with a locking member through hole 42 facilitating the adjustment of the pressure-regulating screw 17, the design of the locking member makes the pressure adjustment good, the pressure does not have a large error due to the loosening caused by long-time use, the problem of the cylinder expansion of the upper cavity is not caused again, the pressure-limiting stability is higher, and the safety is higher.

[0042] The locking piece 4 is provided with a locking piece side positioning plate 44 and a locking piece upper positioning plate 45 outside the locking piece top column 41, the locking piece side positioning plate 44 is provided with a locking piece side fixing hole 46, and the locking piece upper positioning plate 45 is provided with a locking piece upper fixing hole 47; the valve body 1 is provided with a pressure limiting valve core assembly installation cavity 49 for placing the pressure limiting valve core assembly 3, and the valve body 1 is provided with a locking piece side insertion slot 50 corresponding to the locking piece side positioning plate 44, a locking piece upper insertion slot 52 corresponding to the locking piece upper positioning plate 45, a side fixing hole adjusting slot 51 in communication with the locking piece side insertion slot 50 and used for adjusting the locking piece side fixing hole 46, and an upper fixing hole adjusting slot 53 in communication with the locking piece upper insertion slot 52 and used for adjusting the locking piece upper fixing hole 47 outside the pressure limiting valve core assembly installation cavity 49, and the locking piece 4 is fixed on the valve body 1 by using vertical and horizontal forces, compared with the traditional threaded fixing, the stress is more stable and is less likely to slide and loosen, and the fixing can be adjusted at any time according to the position of the pressure regulating screw 17, and the use is more flexible.

[0043] The valve sleeve tightening head 39 is a regular hexagonal structure, and the locking piece end plate 40 is further provided with a tightening head limiting slot 54 outside the locking piece top column 41 for locking the valve sleeve tightening head 39, so that the valve sleeve tightening head is limited, and the locking piece 4 is doubly limited, and the limiting effect is good.

[0044] The diameter of the pressure limiting hole 24 is smaller than the diameter of the pressure regulating hole 29.

[0045] The main liquid discharge hole 22 is arranged at intervals around the circular arc in the middle of the pressure limiting cavity 20, the auxiliary liquid discharge hole 30 is arranged at intervals around the circular arc in the valve seat drainage part 28, the number of the main liquid discharge hole 22 is six, which is convenient for rapid liquid discharge, the auxiliary liquid discharge hole 30 is used for discharging small-flow high-pressure liquid, and the main liquid discharge hole 22 is used for discharging high-pressure large-flow liquid.

[0046] The pressure regulating valve core 15 comprises a pressure regulating valve core sealing part 56 constituting a conical surface seal with the pressure regulating valve seat blocking part 31, a pressure regulating valve core positioning part 57 corresponding to the valve seat drainage part 28, and a pressure regulating spring first positioning column 58 for positioning the end part of the pressure regulating spring 16, and the pressure regulating screw 17 is provided with a pressure regulating spring second positioning column 59 for positioning the end part of the pressure regulating spring 16, so that the spring is bidirectionally positioned, position deviation of the spring caused by impact is effectively prevented, and the safety is high.

[0047] The liquid control valve core assembly 2 includes a liquid control end sleeve 60, an end sleeve joint 61, a liquid control valve seat 62 and a liquid control valve sleeve 63 connected in sequence, a liquid control top rod 64, a top rod spring 65, a liquid control valve core 66 and a valve core spring 67 arranged in the end sleeve joint 61 and the liquid control valve seat 62, and the liquid control end sleeve 60 is provided with an upper cavity inlet 70 communicated with the upper cavity of the column jack.

[0048] The liquid control end sleeve 60 is provided with a liquid control end sleeve partition plate 73 and a top rod action cavity 75, the liquid control end sleeve partition plate 73 is provided with an end sleeve inflow hole 74, the top rod spring 65 is sleeved on the liquid control top rod 64, one end of the top rod spring 65 abuts against the end of the liquid control top rod 64 and the other end abuts against the liquid control valve seat 62, the liquid control valve seat 62 is provided with a liquid supply port 76, the liquid control valve core 66 and the liquid control valve seat 62 form a sealing pair, one end of the valve core spring 67 abuts against the liquid control valve core 66 and the other end abuts against the liquid control valve sleeve 63, and the liquid control valve sleeve 63 is provided with a lower cavity outlet 77 communicated with the lower cavity of the column jack.

[0049] The pressure limiting process of the pressure limiting valve core assembly is as follows: Figure 18 As shown in the figure, the liquid in the upper cavity acts on the pressure regulating valve core 15 through the pressure limiting hole 24 and the pressure regulating hole 29 in sequence, as shown in the figure, Figure 19 When the force borne by the sealing pair of the pressure regulating valve seat 14 and the pressure regulating valve core 15 is greater than the thrust of the pressure regulating spring 16 at the current position, the pressure regulating valve core 15 moves downward to open, and the small-flow high-pressure liquid is discharged from the auxiliary liquid discharge hole 30 of the pressure regulating valve seat; further, as shown in the figure, Figure 20 After the high-pressure liquid in the cavity of the pressure limiting valve core 12 is released by the downward movement of the pressure regulating valve core 15, the pressure in the cavity is reduced, and the pressure limiting valve core 12 also moves downward rapidly to open the sealing state of the pressure limiting valve core 12 and the pressure limiting valve seat 10, and the large-flow liquid is discharged through the main liquid discharge hole 22 of the pressure limiting valve seat 10 to ensure that the upper cavity of the column does not store the high-pressure liquid allowed by the pressure limiting valve core assembly; further, as shown in the figure, Figure 21 When the pressure in the cavity of the pressure limiting valve core 12 is reduced to the thrust value of the pressure regulating spring 16 on the pressure regulating valve core 15 at the current position, the pressure regulating valve core 15 and the pressure regulating valve seat 14 are closed again, and the pressure limiting valve seat 10 is quickly reset under the holding of the pressure limiting spring 13 due to the different sealing force areas at both ends, so that the discharge of large-flow high-pressure liquid is stopped, and the needs of non-internal supercharging for high-pressure liquid are met.

[0050] The above merely describes preferred embodiments of the present application, and is not used to limit the present application, any modification, equivalent replacement and improvement within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A pressure-limited stable hydraulic control check valve, comprising a valve body (1) and a hydraulic control spool assembly (2), characterized in that: Also include pressure limiting valve core assembly (3), the pressure limiting valve core assembly (3) includes pressure limiting valve seat (10), with the pressure limiting valve seat (10) screw together pressure regulating valve sleeve (11), pressure limiting valve core (12), pressure limiting spring (13), pressure regulating valve seat (14), pressure regulating valve core (15), pressure regulating spring (16) and pressure regulating screw (17), the pressure limiting valve seat (10) is equipped with pressure limiting cavity (20) for the pressure limiting valve core (12) is inserted, the pressure limiting cavity (20) front end is equipped with pressure limiting valve seat stop (21) and the pressure limiting valve core (12) forms sealed pair cooperation, the pressure limiting cavity (20) middle part is equipped with main drain hole (22), the pressure limiting spring (13) one end is against the pressure limiting valve core (12) and its other end is against the pressure regulating valve seat (14), the pressure limiting valve core (12) is equipped with pressure limiting hole (24); The pressure regulating valve sleeve (11) is equipped with pressure regulating cavity (26), the pressure regulating valve seat (14) includes valve seat sleeve joint (27) and valve seat drainage part (28), the valve seat sleeve joint (27) is equipped with pressure regulating hole (29) and the pressure limiting hole (24) is communicated, the valve seat drainage part (28) is equipped with secondary drain hole (30) and the pressure regulating hole (29) is communicated vertically, the pressure regulating cavity (26) is equipped with pressure regulating valve seat positioning groove (32) and valve sleeve drain hole (33) and the secondary drain hole (30) is communicated, the pressure regulating valve seat (14) is equipped with valve core action cavity (35) for the pressure regulating valve core (15) is inserted, the valve core action cavity (35) front end is equipped with pressure regulating valve seat stop (31) and the pressure regulating valve core (15) forms sealed pair cooperation, the pressure regulating spring (16) one end is against the pressure regulating valve core (15) and its other end is against the pressure regulating screw (17), the pressure regulating screw (17) is screwed in the pressure regulating valve sleeve (11) end.

2. The pressure-limited, pilot-operated check valve of claim 1, wherein: The pressure regulating valve sleeve (11) is equipped with valve sleeve outer thread (38) and valve sleeve tightening head (39) and the valve body (1) is screwed together, the pressure regulating screw (17) is fixed in the valve sleeve tightening head (39).

3. The pressure-limited, pilot-operated check valve of claim 2, wherein: Also include locking member (4), the locking member (4) includes locking member end plate (40), the locking member end plate (40) is equipped with locking member top column (41) and is placed on the pressure regulating screw (17) outside, the locking member top column (41) is equipped with locking member through hole (42) and is convenient for the pressure regulating screw (17) adjustment.

4. The pressure-limited, pilot-operated check valve of claim 3, wherein: The locking member (4) is equipped with locking member side positioning plate (44) and locking member upper positioning plate (45) outside the locking member top column (41), the locking member side positioning plate (44) is equipped with locking member side fixed hole (46), the locking member upper positioning plate (45) is equipped with locking member upper fixed hole (47) The valve body (1) is provided with a pressure limiting valve core assembly installation cavity (49) for the pressure limiting valve core assembly (3) to be placed in, and the valve body (1) is provided with a locking member side insertion slot (50) corresponding to the locking member side positioning plate (44), a locking member upper insertion slot (52) corresponding to the locking member upper positioning plate (45), a side fixing hole adjusting slot (51) communicating with the locking member side insertion slot (50) and used for adjusting the locking member side fixing hole (46), and an upper fixing hole adjusting slot (53) communicating with the locking member upper insertion slot (52) and used for adjusting the locking member upper fixing hole (47) outside the pressure limiting valve core assembly installation cavity (49).

5. The pressure-limited, pilot-operated check valve of claim 3, wherein: The valve sleeve tightening head (39) is a regular hexagonal structure, and the locking member end plate (40) is further provided with a tightening head limiting slot (54) for locking the valve sleeve tightening head (39) outside the locking member top column (41).

6. The pressure-limited, pilot-operated check valve of claim 1, wherein: The diameter of the pressure limiting hole (24) is smaller than that of the pressure regulating hole (29).

7. The pressure-limited, pilot-operated check valve of claim 1, wherein: The main liquid discharge hole (22) is arranged at the middle part of the pressure limiting cavity (20) at intervals along a circular arc, and the valve seat drainage part (28) is provided with the auxiliary liquid discharge hole (30) at intervals along a circular arc.

8. The pressure-limited, pilot-operated check valve of claim 1, wherein: The pressure regulating valve core (15) comprises a pressure regulating valve core sealing part (56) forming a conical surface seal with the pressure regulating valve seat blocking part (31), a pressure regulating valve core positioning part (57) corresponding to the valve seat drainage part (28), and a pressure regulating spring first positioning column (58) for positioning the end part of the pressure regulating spring (16), and the pressure regulating screw (17) is provided with a pressure regulating spring second positioning column (59) for positioning the end part of the pressure regulating spring (16).

9. The pressure-limited, pilot-operated check valve of claim 1, wherein: The hydraulic control valve core assembly (2) comprises a hydraulic control end sleeve (60), an end sleeve joint (61), a hydraulic control valve seat (62), and a hydraulic control valve sleeve (63) connected in sequence from head to tail, a hydraulic control top rod (64), a top rod spring (65), a hydraulic control valve core (66), and a valve core spring (67) arranged in the end sleeve joint (61) and the hydraulic control valve seat (62), the hydraulic control end sleeve (60) is provided with an upper cavity inlet (70) communicating with the upper cavity of the vertical column jack, the valve body (1) is provided with a valve body middle transfer port (71), one end of the valve body middle transfer port (71) communicates with the upper cavity inlet (70), and the other end thereof communicates with the pressure limiting hole (24).

10. The pressure-limited, pilot-operated check valve of claim 9, wherein: The hydraulic control end sleeve (60) is internally provided with a hydraulic control end sleeve partition plate (73) and a ejector rod action cavity (75), the hydraulic control end sleeve partition plate (73) is provided with an end sleeve inflow hole (74), the ejector rod spring (65) is sleeved on the hydraulic control ejector rod (64), one end of the ejector rod spring (65) abuts against the end of the hydraulic control ejector rod (64) and the other end abuts against the hydraulic control valve seat (62), the hydraulic control valve seat (62) is provided with a hydraulic control liquid supply port (76), the hydraulic control valve core (66) and the hydraulic control valve seat (62) form a sealed pair cooperation, one end of the valve core spring (67) abuts against the hydraulic control valve core (66) and the other end abuts against the hydraulic control valve sleeve (63), the hydraulic control valve sleeve (63) is provided with a lower cavity outlet (77) which is communicated with the lower cavity of the vertical column jack.

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