A shut-off controllable filling check valve

Abstract

The present application relates to a one-way valve, in particular to a filling one-way valve with controllable closing, to solve the problem that the existing technology cannot be controlled to close, the valve core opening degree is easily affected by the medium pressure fluctuation when filling with low pressure and small flow, leading to flow fluctuation, and the reliability is low when filling with small flow. A filling one-way valve with controllable closing includes a first housing, a front valve core arranged in the first housing, a large spring, a small spring, a rear valve core and a valve seat, a second housing and a plunger arranged radially along the first housing, and a power unit connected to the second housing. The plunger is used to fix the rear valve core in the normally open state, and when closing is needed, the plunger is moved by the power unit to unlock the rear valve core.

Description

Technical Field

[0001] This invention relates to check valves, and more specifically to a filling check valve with controllable closure. Background Technology

[0002] Existing check valves are mainly pressure-driven and differential pressure-driven structures. Their valve core closing and opening are mainly affected by the inlet medium pressure or the pressure difference between the mediums at both ends of the valve core, and they cannot be closed in a controlled manner.

[0003] The existing check valves achieve low-pressure, low-flow filling mainly by controlling the spring force to keep the valve core at a small opening. However, the valve core opening is easily affected by the medium pressure fluctuation, the filling flow is prone to fluctuation, and the valve core is prone to chattering, resulting in low reliability of the check valve during low-flow filling. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies, such as the inability to control closure, the spool opening being easily affected by medium pressure fluctuations during low-pressure, low-flow filling, resulting in flow fluctuations and low reliability during low-flow filling. This invention provides a filling check valve with controllable closure.

[0005] To achieve the above objectives, the technical solution provided by this invention is as follows:

[0006] A controllable closing filling check valve, characterized in that it comprises a first housing, a front valve core, a large spring, a small spring, a rear valve core, and a valve seat disposed within the first housing, a second housing and a plunger disposed radially along the first housing, and a power unit connected to the second housing; the first housing comprises a coaxially disposed outer housing and an inner housing, with a flow cavity between the outer housing and the inner housing, and a valve core cavity disposed along the axial direction in the inner housing, with the two ends of the valve core cavity respectively connected to the inlet and outlet of the check valve; a coaxial first through hole and a second through hole are disposed on the sides of the outer housing and the inner housing; a first flow hole is disposed at the end of the inner housing near the inlet, connecting the inlet and the flow cavity, and a second flow hole is disposed at the end near the outlet, connecting the outlet and the flow cavity; a first limiting boss is disposed on the inner wall of the outer housing between the inlet and the first flow hole, and the valve seat is disposed on the outer housing between the outlet and the second flow hole; the front valve core and the rear valve core are disposed in the valve core cavity, with the front valve core facing the inlet direction. The first limiting boss is located on the side away from the inlet; the small spring is located on the side of the front valve core away from the inlet, with one end abutting against the front valve core and the other end connected to the rear valve core; a spring seat is provided on the side of the front valve core away from the inlet; the large spring is located outside the small spring, with one end connected to the spring seat and the other end abutting against the rear valve core; the rear valve core is located on the side of the valve seat away from the outlet and is adapted to the valve seat; a third through hole is coaxially provided on the rear valve core corresponding to the position of the first through hole; a plunger cavity communicating with the first through hole is provided axially inside the second outer shell, the plunger is provided in the plunger cavity, its head is embedded in the first through hole, the second through hole and the third through hole, and its tail is provided with a thin wall cutting along the radial direction; a hollow pressure sleeve is provided on the side of the plunger cavity away from the head of the thin wall cutting, the pressure sleeve abuts against the thin wall cutting and is used to compress the plunger; the other side of the plunger cavity is connected to the power unit, which is used to generate high pressure to drive the plunger movement; a vent hole communicating with the external environment is provided on the second outer shell corresponding to the tail of the plunger.

[0007] Furthermore, the front valve core is provided with multiple filling holes around its central axis for the passage of low-pressure, low-flow media.

[0008] Furthermore, the plunger cavity includes an embedded cavity and a movable cavity arranged along the axial direction;

[0009] The plunger has a stop part at the head, which passes through the embedded cavity, and a limit part at the tail, which is located in the movable cavity. A third limit boss is provided on the outer periphery of the limit part. The diameter of the third limit boss matches the hollow structure of the pressure sleeve. The thin wall cutting is located on the outer periphery of the third limit boss.

[0010] The diameter of the movable cavity matches the outer diameter of the pressure sleeve, and the diameter of the embedded cavity matches the diameter of the stop part.

[0011] Furthermore, the side of the embedded cavity is provided with a mounting groove, in which a pressure ring and a cup-shaped seal are provided. The pressure ring is connected to the second outer shell by a thread and is located on the side of the cup-shaped seal away from the first outer shell; the power unit is connected to the embedded cavity and is located on the side of the pressure ring away from the first outer shell.

[0012] The side of the embedding cavity is provided with a second groove and a third groove at the position between the mounting groove and the first outer shell, both of which are used to install a retaining ring and an O-ring.

[0013] Furthermore, the front valve core includes a front valve head adapted to the valve core cavity and a front valve stem connected to the valve head at one end; the filling hole is located on the front valve head;

[0014] The other end of the front valve stem is provided with a first cavity along the axis, and the side wall of the first cavity is provided with a first step. A small spring is provided in the first cavity, and one end of the spring abuts against the first step.

[0015] The spring seat is located on the outside of the front valve stem.

[0016] Furthermore, the spring seat includes a mounting portion sleeved on the front valve stem and an extension portion formed radially extending from one end of the mounting portion near the front valve core. The extension portion is provided with a plurality of balance holes along the axial direction. The balance holes are used to connect the two sides of the extension portion to balance the pressure on both sides.

[0017] The inner housing is provided with a second limiting boss on the side of the first flow hole away from the inlet. The second limiting boss cooperates with the extension of the spring seat to limit the spring seat.

[0018] Furthermore, the front valve head has a fungus-like shape.

[0019] Furthermore, the rear valve core includes a rear valve head and a rear valve stem connected thereto. The rear valve head is conical and adapted to the valve seat. The rear valve stem is nested in the inner housing, and the third through hole is located on the rear valve stem. Both the rear valve head and the rear valve stem are hollow structures, forming a second cavity along the axial direction. A support seat is provided in the second cavity near the rear valve head.

[0020] The support base includes a small diameter section and a large diameter section. The other end of the small spring is sleeved on the small diameter section. A limit blind hole is provided along the axial direction on the inner side of the rear valve head. The large diameter section of the support base is set in the limit blind hole.

[0021] The side wall of the second cavity is provided with a limiting step, and the other end of the large spring abuts against the limiting step.

[0022] Furthermore, the valve seat is connected to the outer casing by threads, the valve seat mates with the surface of the rear valve head, and both the contact surfaces of the valve seat and the rear valve head are metal sealing surfaces.

[0023] The outer casing has a first groove on the inner side of the valve seat for mounting an O-ring.

[0024] Furthermore, the inner shell is supported and connected to the outer shell by stiffening plates;

[0025] The power unit is an electric detonator or a high-pressure gas source.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. In this invention, the rear valve core is fixed in the normally open position by a radially arranged plunger. When the check valve needs to be closed, the plunger is moved by the power unit to unlock the rear valve core. The rear valve core is then closed under the control of the elastic force of the large spring and the small spring, thus solving the problem that existing check valves cannot be closed in a controlled manner.

[0028] 2. This invention achieves low-pressure, low-flow filling by setting a filling hole on the front valve core, and the front valve core does not need to be opened during the filling process, and the position of the front valve core remains unchanged, thus solving the problem of flow fluctuation and valve core chatter that easily occur when the check valve is filled with low pressure and low flow.

[0029] 3. The present invention provides a balance hole in the extension of the spring seat for the medium to flow through, so that the pressure on both sides of the extension is balanced with the pressure in the flow cavity, thus avoiding deformation of the inner shell and the rear valve stem when the medium pressure is continuously high during use.

[0030] 4. The pressure sleeve provided in this invention is used to limit the movement of the plunger, and also facilitates the installation and setting of the plunger. Attached Figure Description

[0031] Figure 1 This is a cross-sectional view of an embodiment of the present invention;

[0032] Figure 2 These are cross-sectional views of the first and second outer shells according to an embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the front valve core in an embodiment of the present invention; wherein, a is a cross-sectional view of the front valve core, and b is a right view of a;

[0034] Figure 4 This is a cross-sectional view of the valve core in an embodiment of the present invention;

[0035] Figure 5 This is a cross-sectional view of the support base according to an embodiment of the present invention;

[0036] Figure 6 This is a cross-sectional view of the valve seat according to an embodiment of the present invention;

[0037] Explanation of reference numerals in the attached figures:

[0038] 1-First outer casing, 101-Outer casing, 102-Inner casing, 103-Flow cavity, 104-Valve core cavity, 105-Inlet, 106-Outlet, 107-First flow hole, 108-Second flow hole, 109-First through hole, 110-Second through hole, 111-First groove, 2-Front valve core, 201-Front valve head, 202-Front valve stem, 203-Filling hole, 204-First cavity, 3-Spring seat, 301-Mounting part, 302-Extension part, 303-Balance hole, 4-Large spring, 5-Small spring, 6-Rear valve core, 601-Rear valve head, 60 2-Rear valve stem, 603-Third through hole, 604-Limit blind hole, 605-Second cavity, 7-Support seat, 701-Weight reduction hole, 8-Valve seat, 9-Retaining ring, 10-Plunger, 1001-Stop part, 1002-Limit part, 1003-Third limit boss, 11-Pressure sleeve, 12-End cap, 13-Seal, 14-Pressure ring, 15-Electro-explosion tube, 16-Second outer shell, 1601-Embedded cavity, 1602-Moving cavity, 1603-Second groove, 1604-Third groove, 1605-Mounting groove, 1606-Fourth through hole, 17-O-ring. Detailed Implementation

[0039] The controllable closing filling check valve of the present invention, such as Figure 1 As shown, it includes a first housing 1, a front valve core 2, a large spring 4, a small spring 5, a rear valve core 6 and a valve seat 8 disposed in the first housing 1, a second housing 16 disposed radially along the first housing 1, a plunger 10 disposed in the second housing 16 and a power unit disposed on the side of the second housing 16; the power unit is an electric detonation tube 15 or a high-pressure air source, used to drive the plunger 10 to move.

[0040] The first outer casing 1 includes an outer casing 101 and an inner casing 102 arranged coaxially, such as Figure 2 As shown, an annular flow cavity 103 is provided between the outer shell 101 and the inner shell 102. The inner shell 102 is supported and connected to the outer shell 101 by a rib. The inner shell 102 is provided with a valve core cavity 104 along the axial direction. The two ends of the valve core cavity 104 are respectively connected to the inlet 105 and the outlet 106 of the one-way valve. The two ends of the inner shell 102 are respectively provided with a first flow hole 107 and a second flow hole 108. The first flow hole 107 is used to connect the inlet 105 and the flow cavity 103, and the second flow hole 108 is used to connect the outlet 106 and the flow cavity 103. The first flow hole 107 and the second flow hole 108 both include a plurality of small holes evenly distributed along the circumference of the inner shell 102. The outer shell 101 and the inner shell 102 are provided with a coaxial first through hole 109 and a second through hole 110.

[0041] The front valve core 2 is disposed in the valve core cavity 104, and its structure is as follows: Figure 3As shown, it includes a fungus-shaped front valve head 201 and a front valve stem 202 connected to the valve head at one end. The fungus-shaped front valve head 201 is positioned towards the inlet 105, and its outer periphery is adapted to the size of the inner housing 102. A first limiting boss is provided on the inner wall of the outer housing 101 at a position between the inlet 105 and the first flow passage 107. The first limiting boss is adapted to the surface of the front valve head 201. A plurality of filling holes 203 are evenly arranged around the central axis on the surface of the front valve head 201. The front valve head 201 can also be tapered or other shapes. The fungus-shaped front valve head 201 used in this embodiment has a better flow guiding effect. The medium has lower flow resistance. When the front valve core 2 is closed, the first limiting boss limits the front valve head 201 to form a seal. When the front valve core 2 is open, the front valve head 201 is located on the side of the first flow hole 107 away from the inlet 105. The front valve stem 202 is set towards the outlet 106. The other end of the front valve stem 202 is provided with a first cavity 204 along the axis. The side wall of the first cavity 204 is provided with a protruding first step. The first cavity 204 is used to set a small spring 5. One end of the small spring 5 abuts against the first step.

[0042] A spring seat 3 is sleeved on the outer side of the front valve stem 202. The spring seat 3 includes a mounting part 301 sleeved on the front valve stem 202 and an extension part 302 extending radially from the end of the mounting part 301 near the front valve core 2. A second limiting boss is provided on the side of the inner housing 102 away from the inlet 105 of the first flow hole 107. The second limiting boss cooperates with the extension part 302 to limit the spring seat 3. A large spring 4 is sleeved on the spring seat 3, and the end near the inlet 105 abuts against the extension part 302. The extension part 302 is provided with a plurality of balance holes 303 along the axial direction. The balance holes 303 are used to connect the two sides of the extension part 302. The medium enters between the front valve head 201 and the extension part 302 through the filling hole 203, and then through the balance holes 303, so that both sides of the extension part 302 are filled with medium to ensure pressure balance.

[0043] The rear valve core 6 includes a tapered rear valve head 601 and a rear valve stem 602 connected to the rear valve head 601, with the structure as follows: Figure 4 As shown, the rear valve head 601 is positioned towards the outlet 106, and the outer casing 101 is nested with a valve seat 8 located between the outlet 106 and the second flow passage 108. The valve seat 8 has the following structure: Figure 6 As shown, the valve seat 8 is connected to the housing 101 by threads. The surface of the valve seat 8 and the rear valve head 601 are mated, and their contact surfaces are both metal sealing surfaces. When the rear valve core 6 is closed, the valve seat 8 and the rear valve head 601 form a metal seal. When the rear valve core 6 is open, the rear valve head 601 is located on the side of the second flow hole 108 away from the outlet 106, so that the flow cavity 103 and the outlet 106 are connected. The housing 101 is provided with a first groove 111 on the side corresponding to the valve seat 8 for setting the O-ring 17.

[0044] The rear valve stem 602 is nested in the inner housing 102, and a third through hole 603 coaxial with it is provided at the position corresponding to the first through hole 109; both the rear valve head 601 and the rear valve stem 602 are hollow structures, forming a second cavity 605 along the axial direction. A support seat 7 is provided in the second cavity 605 near the rear valve head 601, and the structure of the support seat 7 is as follows. Figure 5 As shown, the support 7 includes a small diameter section and a large diameter section. The other end of the small spring 5 is sleeved on the small diameter section, and its end abuts against the end face of the large diameter section near the small diameter section. The rear valve head 601 is provided with a limit blind hole 604 along the axial direction. The large diameter section of the support 7 is set in the limit blind hole 604. The support 7 is provided with a weight reduction hole 701 along the axial direction. The side wall of the second cavity 605 is provided with a limit step. The other end of the large spring 4 abuts against the limit step. During use, the large spring 4 and the small spring 5 are always in a compressed state.

[0045] The second outer casing 16 has an axially arranged plunger cavity inside, which includes an embedded cavity 1601 and a movable cavity 1602 coaxially arranged. The embedded cavity 1601 is coaxial with and communicates with the first through hole 109. The plunger 10 includes a stop part 1001 with a smaller diameter and a limiting part 1002 with a larger diameter. The stop part 1001 passes through the embedded cavity 1601, the first through hole 109, the second through hole 110, and the third through hole 603 to limit the rear valve core 6 and keep the rear valve core 6 in the normally open position. The diameter of the embedded cavity 1601 matches that of the stop part 1001. The limiting part 1002... 2 is located in the active cavity 1602, and a third limiting boss 1003 is provided on the outer periphery. The outer periphery of the third limiting boss 1003 extends radially to form a thin wall. A hollow pressure sleeve 11 is provided on the side of the thin wall away from the head in the active cavity 1602. The pressure sleeve 11 abuts against the thin wall and presses the plunger 10 by the thin wall to prevent the stop part 1001 from accidentally coming out of the third through hole 603, which would cause the rear valve core 6 to close. The hollow structure includes a large diameter section and a small diameter section. The diameter of the large diameter section matches the diameter of the third limiting boss 1003, which serves as the active space for the plunger 10.

[0046] An installation groove 1605 is provided on the side of the embedded cavity 1601 near the movable cavity 1602. A pressure ring 14 and a bowl-shaped seal 13 are provided in the installation groove 1605. The pressure ring 14 is connected to the second outer shell 16 by threads and is located on the side of the bowl-shaped seal 13 away from the first outer shell 1. The end face of the pressure ring 14 presses tightly against the bowl-shaped seal 13 to limit its movement.

[0047] The embedded cavity 1601 is located on the side of the pressure ring 14 away from the first outer shell 1 and is connected to the power unit. A sealed cavity is formed between the pressure ring 14 and the thin wall being cut, so that the electric explosion airflow or high pressure airflow generated by the power unit forms a high pressure driving plunger to move and break through the thin wall in the sealed cavity.

[0048] The side of the embedded cavity 1601, located between the mounting groove 1605 and the first outer shell 1, has a second groove 1603 and a third groove 1604, both used to house the retaining ring 9 and the O-ring 17 for sealing the medium. An end cap 12 is located at the end of the movable cavity 1602 furthest from the first outer shell 1. The end cap 12 is threaded onto the second outer shell 16. The small-diameter section of the hollow structure of the pressure sleeve 11 is close to the end cap 12. Both the end face of the small-diameter section and the end cap 12 have vent holes for connecting to the external environment to balance the pressure in the movable cavity 1602.

[0049] The second outer casing 16 has a fourth through hole 1606 on its side. The outer end of the fourth through hole 1606 is connected to the power unit, and the inner end is connected to the embedded cavity 1601 located at the end of the pressure ring 14 away from the first outer casing 1. When in use, the electric explosion gas or high pressure gas enters the embedded cavity 1601, pushing the plunger 10 to move along the axis away from the first outer casing 1 to open. At the same time, the thin wall is cut and broken through, and the stop part 1001 of the plunger 10 leaves the third through hole 603, releasing the restriction on the rear valve core 6.

[0050] The specific usage process of this invention is as follows:

[0051] The installation state of the one-way valve of the present invention is as follows: Figure 1 As shown, the front valve core 2 is normally closed, and the rear valve core 6 is locked in the normally open position by the plunger 10. The medium difference on both sides of the front valve core 2 is lower than the opening pressure difference of the front valve core 2. The medium in the inlet 105 passes through the filling hole 203 of the front valve core 2, and after passing through the first flow hole 107, the flow cavity 103, and the second flow hole 108 on the inner shell 102, it flows to the outlet 106 through the normally open rear valve core 6 and the valve seat 8, realizing low-pressure and low-flow filling.

[0052] When the pressure difference between the medium on both sides of the current valve core 2 is higher than the opening pressure difference of the front valve core 2, the front valve core 2 opens, and the medium flows through the inlet 105, the first flow hole 107, the flow chamber 103, the second flow hole 108, and through the normally open rear valve core 6 and valve seat 8 to the outlet 106, thus achieving high-pressure and high-flow filling.

[0053] When the front valve core 2 is open, the pressure difference of the medium on both sides of the front valve core 2 is lower than the opening pressure difference of the front valve core 2. The front valve core 2 moves from the open state to the closed state to prevent the reverse flow of a large flow of medium.

[0054] When the check valve needs to be completely closed, the electric detonator 15 is energized and detonated. The high-temperature and high-pressure gas acts on the plunger 10, causing the thin wall to rupture. The plunger 10 moves upward, and the stop part 1001 is pulled out from the third through hole 603, which unlocks the rear valve core 6. Under the action of the spring force and the medium, the rear valve core 6 moves towards the outlet 106 to the valve seat 8 to close, forming a seal, so that the check valve can be closed in a controllable manner.

Claims

1. A controllable closing filling check valve, characterized in that: It includes a first housing (1), a front valve core (2), a large spring (4), a small spring (5), a rear valve core (6) and a valve seat (8) disposed in the first housing (1), a second housing (16) and a plunger (10) disposed radially along the first housing (1), and a power unit connected to the second housing (16); The first outer shell (1) includes an outer shell (101) and an inner shell (102) arranged coaxially. A flow cavity (103) is provided between the outer shell (101) and the inner shell (102). The inner shell (102) is provided with a valve core cavity (104) along the axial direction. The two ends of the valve core cavity (104) are respectively connected to the inlet (105) and outlet (106) of a one-way valve. The outer shell (101) and the inner shell (102) are provided with a coaxial first through hole (109) and a second through hole (110). The inner shell (102) has a first flow hole (107) connecting the inlet (105) and the flow cavity (103) at one end near the inlet (105), and a second flow hole (108) connecting the outlet (106) and the flow cavity (103) at one end near the outlet (106); the inner wall of the outer shell (101) has a first limiting boss located between the inlet (105) and the first flow hole (107), and the valve seat (8) is located between the outlet (106) and the second flow hole (108) on the outer shell (101). The front valve core (2) and the rear valve core (6) are disposed in the valve core cavity (104). The front valve core (2) is disposed facing the inlet (105) and is located on the side of the first limiting boss away from the inlet (105). The small spring (5) is located on the side of the front valve core (2) away from the inlet (105), with one end abutting against the front valve core (2) and the other end connected to the rear valve core (6); a spring seat (3) is provided on the side of the front valve core (2) away from the inlet (105); the large spring (4) is located outside the small spring (5), with one end connected to the spring seat (3) and the other end abutting against the rear valve core (6); The rear valve core (6) is located on the side of the valve seat (8) away from the outlet (106) and is adapted to the valve seat (8); the rear valve core (6) is coaxially provided with a third through hole (603) corresponding to the position of the first through hole (109). The second outer shell (16) has a plunger cavity connected to the first through hole (109) along the axial direction. The plunger (10) is set in the plunger cavity. Its head is embedded in the first through hole (109), the second through hole (110) and the third through hole (603). The tail is provided with a thin wall that cuts through it along the radial direction. The plunger cavity is provided with a hollow pressure sleeve (11) on the side of the thin wall that cuts through it away from the head. The pressure sleeve (11) abuts against the thin wall that cuts through it and is used to press the plunger (10). The plunger cavity is connected to the power unit on the other side of the thin wall that cuts through it. The power unit is used to generate high pressure to drive the plunger (10) to move. When working, the rear valve core (6) is fixed in the normally open position by the plunger (10). When it needs to be closed, the power unit moves the plunger (10) to unlock the rear valve core (6). The rear valve core (6) is controlled to close under the elastic force of the large spring (4) and the small spring (5). The second outer shell (16) is provided with a vent hole at the tail of the plunger (10) to connect to the external environment.

2. The controllable closing filling check valve according to claim 1, characterized in that: The front valve core (2) is provided with multiple filling holes (203) around the central axis for low-pressure, low-flow media to pass through.

3. A controllable closing filling check valve according to claim 2, characterized in that: The plunger cavity includes an embedded cavity (1601) and a movable cavity (1602) arranged along the axial direction. The head of the plunger (10) is a stop part (1001) that passes through the embedded cavity (1601), and the tail is a limiting part (1002) located in the movable cavity (1602). A third limiting boss (1003) is provided on the outer periphery of the limiting part (1002). The diameter of the third limiting boss (1003) matches the hollow structure of the pressure sleeve (11). The thin wall cutting is located on the outer periphery of the third limiting boss (1003). The diameter of the active cavity (1602) matches the outer diameter of the pressure sleeve (11), and the diameter of the embedded cavity (1601) matches the diameter of the stop part (1001).

4. A controllable closing filling check valve according to claim 3, characterized in that: The side of the embedded cavity (1601) is provided with a mounting groove (1605), and a pressure ring (14) and a bowl-shaped seal (13) are provided in the mounting groove (1605). The pressure ring (14) is connected to the second outer shell (16) by threads and is located on the side of the bowl-shaped seal (13) away from the first outer shell (1). The power unit is connected to the embedded cavity (1601) on the side of the pressure ring (14) away from the first outer shell (1); The side of the embedded cavity (1601) is provided with a second groove (1603) and a third groove (1604) located between the mounting groove (1605) and the first outer shell (1), both of which are used to set the retaining ring (9) and the O-ring (17).

5. A controllable closing filling check valve according to claim 4, characterized in that: The front valve core (2) includes a front valve head (201) adapted to the valve core cavity (104) and a front valve stem (202) connected to the valve head at one end; the filling hole (203) is located on the front valve head (201); The other end of the front valve stem (202) is provided with a first cavity (204) along the axis. The side wall of the first cavity (204) is provided with a first step. The small spring (5) is provided in the first cavity (204), and one end abuts against the first step. The spring seat (3) is located on the outside of the front valve stem (202).

6. A controllable closing filling check valve according to claim 5, characterized in that: The spring seat (3) includes a mounting part (301) sleeved on the front valve stem (202) and an extension part (302) formed by extending radially from one end of the mounting part (301) near the front valve core (2). The extension part (302) is provided with a plurality of balance holes (303) along the axial direction. The balance holes (303) are used to connect the two sides of the extension part (302) to balance the pressure on both sides. The inner housing (102) is provided with a second limiting boss on the side of the first flow hole (107) away from the inlet (105). The second limiting boss cooperates with the extension (302) of the spring seat (3) to limit the spring seat (3).

7. A controllable closing filling check valve according to claim 6, characterized in that: The front valve head (201) is fungus-shaped.

8. A controllable closing filling check valve according to any one of claims 1-7, characterized in that: The rear valve core (6) includes a rear valve head (601) and a rear valve stem (602) connected thereto. The rear valve head (601) is conical and is adapted to the valve seat (8). The rear valve stem (602) is nested in the inner shell (102). The third through hole (603) is located on the rear valve stem (602). Both the rear valve head (601) and the rear valve stem (602) are hollow structures, forming a second cavity (605) along the axial direction. A support seat (7) is provided in the second cavity (605) near the rear valve head (601). The support base (7) includes a small diameter section and a large diameter section. The other end of the small spring (5) is sleeved on the small diameter section. A limit blind hole (604) is provided on the inner side of the rear valve head (601) along the axial direction. The large diameter section of the support base (7) is set in the limit blind hole (604). The side wall of the second cavity (605) is provided with a limiting step, and the other end of the large spring (4) abuts against the limiting step.

9. A controllable closing filling check valve according to claim 8, characterized in that: The valve seat (8) is connected to the outer shell (101) by a thread. The valve seat (8) is mated with the surface of the rear valve head (601), and the contact surfaces of the valve seat (8) and the rear valve head (601) are both metal sealing surfaces. The outer shell (101) has a first groove (111) on the inner side of the valve seat (8) for setting an O-ring (17).

10. A controllable closing filling check valve according to claim 9, characterized in that: The inner shell (102) is supported and connected to the outer shell (101) by stiffening plates; The power unit is an electric detonator (15) or a high-pressure gas source.

Images