Multi-ball control type one-way valve

Abstract

The invention discloses a multi-ball control type one-way valve, and relates to the technical field of downhole tools for oil and gas well reservoir transformation. The pressure difference between the pressure chamber and the balance chamber is controlled through the cooperation of control balls of different specifications thrown into different seating conical surfaces and high-pressure fluid pumped from a wellhead, so that the hydraulic pressure borne by the piston is controlled, the piston is pushed to move upwards or downwards, and the purposes of unlocking and limiting the valve clack mechanism to block an inner channel are achieved. And under-pressure dragging is realized. According to the one-way valve, the mode that multiple control balls are thrown and hydraulic pressure is combined is innovatively adopted, the core working principle that opening and closing actions of the one-way valve are completed under the combined action of all the mechanisms is adopted, under-pressure dragging layer transferring fracturing is achieved, operation is easy, and efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole tools for reservoir stimulation in oil and gas wells, and more specifically to a multi-ball controlled one-way valve. Background Art

[0002] A one-way valve is a commonly used downhole tool in the field of oil and gas field development, and it is required to directionally open and close the inner channel of the tubing under different application conditions. During the fracturing construction of double-pack single-card in the Changqing Oilfield area, after one layer of fracturing is completed, the pressure in the wellbore is released by blowout, and after the pressure is reduced to a safe range, the tool is dragged to the next layer. However, it is impossible to drag with pressure, resulting in a long construction period.

[0003] The patent document with the publication number CN220015125U discloses a differential pressure controlled one-way valve and a tool string, which includes a piston passing through a sleeve, and a gap is formed between the piston and the sleeve. A first flange is provided on the outer wall of the piston, and the first flange fits with the inner wall of the sleeve. The first flange divides the gap between the piston and the sleeve into a first chamber located above and a second chamber located below. By continuously pumping fluids into the annulus between the casing and the tubing and the tubing respectively, the piston can move up and down along the axial direction of the sleeve under the action of the pressure difference between the first chamber and the second chamber to control the opening or closing of the one-way valve. The operation is cumbersome and the efficiency is not high. For this construction process, there is an urgent need to design a simple operation tubing plugging tool to achieve double-pack single-card dragging with pressure and improve the construction efficiency. Summary of the Invention

[0004] In order to overcome the defects existing in the above-mentioned prior art, the present invention discloses a multi-ball controlled one-way valve, which innovatively adopts a combination of "throwing multiple control balls and hydraulic pressure", and completes the core working principle of the opening and closing actions of the one-way valve under the joint action of various mechanisms, realizing dragging with pressure to the next layer for fracturing, with simple operation and high efficiency.

[0005] In order to achieve the above purposes, the technical solution adopted by the present invention is as follows: A multi-ball controlled one-way valve, the one-way valve includes an upper joint, a lower joint, a connecting cylinder, a bushing, a piston, a valve flap mechanism and an inner channel for liquid flow. The connecting cylinder, the bushing and the piston are arranged between the upper joint and the lower joint and are sleeved from outside to inside in sequence. The upper and lower joints are arranged at both ends. The valve flap mechanism is installed between the piston and the lower joint, and the piston restricts the valve flap mechanism from blocking the inner channel. Its characteristics are as follows: The piston includes an outward first flange and a second flange. The first flange fits with the flange of the bushing, and the second flange fits with the inner wall of the bushing. The first flange and the second flange divide the gap between the piston and the bushing into a pressure chamber Ⅰ above, a balance chamber in the middle and a pressure chamber Ⅱ below; It also includes a liquid control ball seat arranged above the piston, with its lower end inserted into the gap between the piston and the bushing. Two differently sized seating conical surfaces Ⅰ and Ⅱ are arranged on the inner wall of the liquid control ball seat, and seating conical surface Ⅱ is located above seating conical surface Ⅰ; a pressure passage Ⅰ is arranged above seating conical surface Ⅱ and is connected to pressure chamber Ⅰ, and a pressure passage Ⅱ is arranged between seating conical surface Ⅰ and seating conical surface Ⅱ and is connected to pressure chamber Ⅱ.

[0006] The pressure passage Ⅰ includes a diversion hole Ⅰ and a diversion channel Ⅰ. The diversion hole Ⅰ is arranged above seating conical surface Ⅱ and is connected to pressure chamber Ⅰ through the diversion channel Ⅰ arranged along the gap between the liquid control ball seat and the bushing; the pressure passage Ⅱ includes a diversion hole Ⅱ and a diversion channel Ⅱ. The diversion hole Ⅱ is arranged between seating conical surface Ⅰ and seating conical surface Ⅱ and is connected to pressure chamber Ⅱ through the diversion channel Ⅱ arranged along the gap between the bushing and the connecting cylinder.

[0007] The seating conical surface Ⅰ is a diversion groove conical surface.

[0008] The piston includes an upper piston and a lower piston, which are connected by screws. The cross-sectional area of the first flange of the upper piston is smaller than that of the second flange of the lower piston.

[0009] A pressure balance hole is arranged at the connection of the piston, and the pressure balance hole is connected to the inner channel and the balance chamber.

[0010] When the inner channel is closed, the maximum distance that the piston moves upward corresponds to the distance that the piston moves upward when releasing the restriction of the valve flap mechanism.

[0011] In the state where the one-way valve is open, the piston restricts the valve flap mechanism in the gap between the piston and the lower joint. After the piston moves upward, the valve flap mechanism blocks the lower end of the inner channel of the one-way valve to close the one-way valve.

[0012] It is characterized in that the lower end of the lower piston includes a third flange.

[0013] It is characterized in that the one-way valve further includes a locking mechanism arranged above the valve flap mechanism and abutted against it. The locking mechanism includes a locking claw, and the locking claw is engaged with the third flange on the piston.

[0014] The locking mechanism includes an adjusting ring for adjusting the locking force of the locking claw, and the adjusting ring is installed on the locking claw.

[0015] The beneficial effects of the present invention: 1. Compared with the prior art, a multi-ball controlled one-way valve is disclosed. It innovatively adopts the combination of "throwing multiple control balls and hydraulic pressure", and under the combined action of various mechanisms, the core working principle of opening and closing the one-way valve is completed. Multiple control balls are located on conical surfaces of different specifications, and the high-pressure fluid injected by the wellhead pump controls the hydraulic pressure on the piston, thereby completing the directional movement of the whole piston, controlling the opening and closing of the internal channel of the one-way valve, and realizing pressure-driven layer-by-layer fracturing. The operation is simple and the efficiency is high.

[0016] 2. In the present invention, the flange areas of the upper piston and the lower piston are different in size. This design is completed by segmented connection. It is difficult and unnecessary to directly machine a double-flange piston that meets the process requirements. In the current market, connecting pistons with different flange areas can also achieve the effect of the present invention, and the installation is simple, the cost performance is higher, and the practicability is stronger. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the one-way valve of the present invention; Figure 2 It is a schematic diagram of section A of the present invention; Figure 3 It is a schematic diagram of the structure of the hydraulic control valve seat of the present invention; Figure 4 It is a schematic diagram of the structure of the pressure passage of the present invention; Figure 5 It is a schematic diagram of the open state of the multi-ball controlled one-way valve of the present invention; Figure 6 It is a schematic diagram of the closed state of the multi-ball controlled one-way valve of the present invention; Reference Numerals: 1. Upper joint; 2. Hydraulic control valve seat; 21. Seating cone surface Ⅰ; 22. Seating cone surface Ⅱ; 3. Connecting cylinder; 4. Bushing; 5. Upper piston; 51. Pressure chamber Ⅰ; 52. Diversion hole Ⅰ; 53 Diversion channel Ⅰ; 54. Balance channel; 55. Balance chamber; 6. Lower piston; 61. Pressure chamber Ⅱ; 62. Diversion hole Ⅱ; 63. Diversion channel Ⅱ; 7. Adjusting ring; 8. Locking claw; 9. Valve flap mechanism; 10. Lower joint. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The concept, specific structure and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments and the drawings, so as to fully understand the purpose, features and effects of the present invention.

[0019] Embodiment 1 As Figures 1 to 6A multi-ball controlled one-way valve as shown, the one-way valve includes an upper joint 1, a lower joint 10, a connecting cylinder 3, a bushing 4, a piston, a valve flap mechanism 9 and an inner channel for liquid flow. The connecting cylinder 3, the bushing 4 and the piston are arranged between the upper joint and the lower joint and are sleeved in sequence from outside to inside. The valve flap mechanism 9 is installed between the piston and the lower joint 10, and the piston restricts the valve flap mechanism 9 from blocking the inner channel.

[0020] The piston includes a first flange and a second flange. The first flange fits with the inward flange of the bushing 4, and the second flange fits with the inner wall of the bushing. The first flange and the second flange divide the gap between the piston and the bushing into a pressure chamber Ⅰ 51 above, a balance chamber 54 in the middle and a pressure chamber Ⅱ 61 below. Each chamber is provided with a sealing ring to ensure its sealing performance. The pressure chamber Ⅰ 51 is composed of a liquid control seat 2, the bushing 4, the first flange of the upper piston 5 and its seal. The balance chamber 54 is composed of the first flange of the upper piston 5, the second flange of the lower piston 6 and the bushing 4 and its seal. The pressure chamber Ⅱ 61 is composed of the valve flap mechanism 9, the bushing 4 and the second flange of the lower piston 6 and its seal. The function of the balance chamber 54 is to ensure a pressure difference between the pressure chamber Ⅰ, the pressure chamber Ⅱ and the balance chamber 54. It also includes a liquid control seat 2 arranged above the upper piston 5. The lower end of the liquid control seat 2 is plugged and inserted between the upper piston 5 and the bushing 4. There are two differently sized seating cones Ⅰ 21 and seating cones Ⅱ 22 arranged on the inner wall of the liquid control seat 2, and the seating cones Ⅱ 22 are located above the seating cones Ⅰ 21. Above the seating cones Ⅱ 22, there is a pressure passage Ⅰ connected to the pressure chamber Ⅰ 51. Between the seating cones Ⅰ 21 and the seating cones Ⅱ 22, there is a pressure passage Ⅱ connected to the pressure chamber Ⅱ 61. The pressure passage Ⅰ includes a diversion hole Ⅰ 52 and a diversion channel Ⅰ 53. The diversion hole Ⅰ 52 is arranged above the seating cones Ⅱ 22 and communicates with the pressure chamber Ⅰ 51 through the diversion channel Ⅰ 53 arranged along the gap between the liquid control seat 2 and the bushing 4. The pressure passage Ⅱ includes a diversion hole Ⅱ 62 and a diversion channel Ⅱ 63. The diversion hole Ⅱ 62 is arranged between the seating cones Ⅰ 21 and the seating cones Ⅱ 22 and communicates with the pressure chamber Ⅱ 61 through the diversion channel Ⅱ 63 arranged along the gap between the bushing 4 and the connecting cylinder 3.

[0021] When high-pressure fluid is pumped at the wellhead, by putting the first control ball onto the seating cones Ⅰ 21, the piston can be pushed to move upward by the liquid pressure difference formed among the pressure chamber Ⅰ 51, the pressure chamber Ⅱ 61 and the balance chamber 54. Then, by putting the second control ball onto the seating cones Ⅱ 22, the piston can be pushed to move downward by the liquid pressure difference formed among the pressure chamber Ⅰ 51, the pressure chamber Ⅱ 61 and the balance chamber 54.

[0022] As an implementation manner of this embodiment, as Figure 6As shown, the sitting conical surface I 21 is set as a diversion groove conical surface. When the first control ball sits at the sitting conical surface I 21, through the diversion groove structure, it not only ensures the liquid flow channel for pumping the second control ball, but also provides the sitting position for the first control ball. Through the diversion groove structure, the liquid flow channel becomes smaller, achieving a throttling effect, and creating a pressure difference between the upper and lower parts of the first control ball.

[0023] When opening, by throwing the first control ball to sit at the lower part of the liquid control seat 2 with a diversion groove conical surface, that is, the sitting conical surface I 21, when the high-pressure fluid pumped from the wellhead passes through the diversion groove, it achieves a throttling effect, creating a pressure difference between the upper and lower parts of the control ball, thereby creating a pressure difference between the pressure chamber and the balance chamber. At this time, the high-pressure liquid enters the pressure chamber I 51 through the diversion hole I 52 and the diversion channel I 53, forming a high-pressure chamber, and enters the pressure chamber II 61 through the diversion hole II 62 and the diversion channel II 63, forming a high-pressure chamber. Due to the different cross-sectional areas of the first flange and the second flange on the piston, that is, the different force-bearing areas, resulting in different liquid pressures. The liquid pressure of the pressure chamber II 61 on the second flange is upward, and the liquid pressure of the pressure chamber I 51 on the first flange is downward. The upward liquid pressure is greater than the downward liquid pressure. Under the action of the liquid pressure difference, the upper piston 5 and the lower piston 6 connected together move upward simultaneously, and the piston releases the restriction on the valve flap mechanism 9. The valve flap opens under the action of the spring to close the inner channel and block the lower pressure in the tubing, thereby realizing dragging the pipe string under pressure. After adjusting the drill string to the designed position, throw the second control ball to sit at the upper conical surface of the liquid control seat 2, that is, the sitting conical surface II 22, to block the pressure below the control ball. At this time, when the wellhead pumps high pressure, the high-pressure liquid enters the pressure chamber I 51 through the diversion hole I 52 and the diversion channel I 53 to form a high-pressure chamber. At this time, both the pressure chamber II 61 and the balance chamber 54 are low-pressure chambers, and a pressure difference is formed between the pressure chamber I 51 and the balance chamber 54. Under the action of the pressure difference, the liquid pressure on the piston is downward, and the upper piston 5 and the lower piston 6 connected together move downward simultaneously, driving the valve flap to return to its position and opening the inner channel of the tubing. Then, the two control balls placed are returned by the reverse circulation method to clear the fracturing channel in the tubing. When performing the next section of construction, the above process can be repeated to realize the double-pack single-slip pressure-dragging multi-stage fracturing construction.

[0024] Embodiment 2 As Figures 1 to 6 shown, on the basis of Embodiment 1, this embodiment is further elaborated. The piston includes an upper piston 5 and a lower piston 6, which are connected by screws. The cross-sectional area of the first flange located on the upper piston 5 is smaller than the cross-sectional area of the second flange located on the lower piston 6.

[0025] In this design, when the first control ball is thrown, the pressures in the pressure chamber I 51 and the pressure chamber II 61 are the same. Through the liquid pressure calculation formula It can be seen that the larger the cross-sectional area, the greater the hydraulic pressure under the same pressure condition. The hydraulic pressure from the pressure chamber II 61 to the second flange is upward, and the hydraulic pressure from the pressure chamber I 51 to the first flange is downward. Since the function of the first control ball is to push the upper piston 5 and the lower piston 6 upward as a whole, the cross-sectional area of the second flange should be larger than that of the first flange. The first and second flanges of the segmented-connected upper piston 5 and lower piston 6 are designed with different-sized force-bearing cross-sectional areas, which cooperate with the control ball to form the control of the hydraulic pressure, complete the directional movement of the piston as a whole, and control the closing of the inner channel. When the second ball is inserted, the pressure in the pressure chamber II 61 decreases due to the blockage of the channel, and the channel in the pressure chamber I 51 is unblocked, resulting in increased pressure. When the pressure difference between the two pressure chambers reaches the set value, the piston moves downward as a whole to control the opening of the inner channel. Such a control method combining ball insertion and hydraulic pressure is simple to operate and more practical.

[0026] The reason for using the segmented connection for the piston is to facilitate finding flanges with different cross-sectional areas for connection. There are mature piston products with different cross-sectional areas on the market. If a piston with two flanges is machined as a whole, it will increase the machining difficulty, have a low cost performance, and low economic benefits.

[0027] As an implementation manner of this embodiment, a pressure balance hole 55 is provided at the connection between the upper piston 5 and the lower piston 6, connecting the inner channel of the connection check valve and the balance chamber 55, so that the pressure fluid in the chamber can be discharged through the pressure balance hole 55 to ensure that the upper piston 5 and the lower piston 6 can move up and down as a whole.

[0028] As an implementation manner of this embodiment, when the inner channel is closed, the maximum upward movement distance of the piston corresponds to the upward movement distance when the piston releases the restriction on the valve flap mechanism 9. When the piston moves upward, it will encounter a step below the seating cone surface I of the liquid control seat 2 to reach the maximum upward movement distance. At this time, the lower end of the lower piston 6 just completely releases the restriction on the valve flap mechanism 9. An overly long upward movement distance is unnecessary, and an overly short one cannot completely release the restriction on the valve flap mechanism 9.

[0029] Embodiment 3 As Figures 1 to 6 shown, this embodiment further elaborates on the present invention. In the open state of the check valve, the piston can restrict the valve flap mechanism 9 in the gap between the piston and the lower joint 10. After the upper piston 5 and the lower piston 6 move upward as a whole, the valve flap mechanism 9 can block the lower end of the inner channel of the check valve to close the check valve. The valve flap is restricted in the gap between the lower piston 6 and the valve flap seat. When the piston moves upward due to the hydraulic pressure difference, the restricting force of the lower piston 6 on the valve flap disappears, and the elastic member on the valve flap mechanism 9 can apply an elastic force to drive the valve flap to flip upward to block the lower end of the lower piston 6, achieving the purpose of blocking the inner channel of the check valve.

[0030] As an implementation manner of this embodiment, the lower end of the lower piston 6 includes a third flange.

[0031] As an implementation manner of this embodiment, the one-way valve further includes a locking mechanism disposed above and abutted against the valve flap mechanism 9. The locking mechanism includes a locking claw 8, which is engaged with the third flange of the lower piston 6 and can lock the piston at the lowermost end of the moving stroke, so that the one-way valve remains in an open state. There is a ratchet on the front end of the locking claw 8, and the ratchet can latch onto the third flange on the lower piston 6 to lock the piston. When the first control ball is bet, the hydraulic pressure on the piston is upward, and the hydraulic pressure needs to overcome the locking force of the locking claw 8 to move the piston upward.

[0032] As an implementation manner of this embodiment, the locking mechanism includes an adjusting ring 7, which is installed on the locking claw 8 and is responsible for adjusting the locking force of the locking claw 8. The adjusting ring 7 can be sleeved on the locking claw 8, and the adjusting ring 7 and the locking claw 8 can be in threaded cooperation. By rotating the adjusting ring 7, the adjusting ring 7 can move up and down along the locking claw 8, and then the length of the lever arm of the ratchet at the front end of the locking claw 8 can be adjusted to change the locking force between the ratchet and the third flange. Specifically, when the adjusting ring 7 moves upward along the locking claw 8, the locking force of the locking claw 8 on the lower piston 6 increases; when the adjusting ring 7 moves downward along the locking claw 8, the locking force of the locking claw 8 on the piston decreases. The present invention does not limit the locking mechanism, and it can also be other components that can be used to lock the piston, such as a slide rail and chute cooperation, etc.

[0033] For a better understanding of the present invention, the working principle of the present invention will be described completely as follows: When starting, by dropping the first control ball to the conical surface with a diversion groove at the lower part of the liquid control seat 2, i.e., the seating conical surface I 21, when the high-pressure fluid pumped from the wellhead passes through the diversion groove, a throttling effect is achieved, and a pressure difference is formed between the upper and lower parts of the control ball, thereby forming a pressure difference between the pressure chamber and the balance chamber. At this time, the high-pressure liquid enters the pressure chamber I 51 through the diversion hole I 52 and the diversion channel I 53 to form a high-pressure chamber, and enters the pressure chamber II 61 through the diversion hole II 62 and the diversion channel II 63 to form a high-pressure chamber. Since the cross-sectional areas of the first flange and the second flange on the piston are different, that is, the force-bearing areas are different, resulting in different hydraulic pressures. The hydraulic pressure of the pressure chamber II 61 on the second flange is upward, and the hydraulic pressure of the pressure chamber I 51 on the first flange is downward. The upward hydraulic pressure is greater than the downward hydraulic pressure. Under the action of the hydraulic pressure difference, the upper piston 5 and the lower piston 6 connected together move upward simultaneously, and the piston releases the restriction on the valve flap mechanism 9. The valve flap opens under the action of the spring to close the inner channel and block the lower pressure in the tubing, thereby realizing the pressure-driven pipe string. After adjusting the drill string to the designed position, drop the second control ball to the conical surface at the upper part of the liquid control seat 2, i.e., the seating conical surface II 22, to block the pressure below the control ball. At this time, when the wellhead pumps high pressure, the high-pressure liquid enters the pressure chamber I 51 through the diversion hole I 52 and the diversion channel I 53 to form a high-pressure chamber. At this time, both the pressure chamber II 61 and the balance chamber 54 are low-pressure chambers, and a pressure difference is formed between the pressure chamber I 51 and the balance chamber 54. Under the action of the pressure difference, the hydraulic pressure on the piston is downward, and the upper piston 5 and the lower piston 6 connected together move downward simultaneously to drive the valve flap to return to its position and open the inner channel of the tubing. Then, the two control balls placed are returned by the reverse circulation method to clear the fracturing channel in the tubing. When the next section of construction is carried out, the above process can be repeated to realize the multi-stage fracturing construction with double sealing, single clamping, and pressure-driven.

[0034] The above has specifically described the embodiments of the present invention, but the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent variations or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A multi-ball controlled one-way valve, the one-way valve comprising an upper joint (1), a lower joint (10), a connecting cylinder (3), a bushing (4), a piston, a valve flap mechanism (9) and an inner channel for liquid flow, the connecting cylinder (3), the bushing (4) and the piston are arranged between the upper joint (1) and the lower joint (10) and are sleeved in sequence from outside to inside, the valve flap mechanism (9) is installed between the piston and the lower joint (10), and the piston restricts the valve flap mechanism (9) from blocking the inner channel, and is characterized in that: The piston includes an outward first flange and a second flange, the first flange fits with the inward flange of the bushing (4), the second flange fits with the inner wall of the bushing, and the first flange and the second flange divide the gap between the piston and the bushing into a pressure chamber I (51) above, a balance chamber (54) in the middle and a pressure chamber II (61) below; It further includes a liquid control ball seat (2) arranged above the piston, the lower end of the liquid control ball seat (2) is plugged and inserted into the gap between the piston and the bushing (4) and abuts against the bushing flange, two differently sized seating cones I (21) and seating cones II (22) are arranged on the inner wall of the liquid control ball seat (2), and the seating cone II (22) is located above the seating cone I (21); a pressure passage I is arranged above the seating cone II (22) and is connected to the pressure chamber I (51), and a pressure passage II is arranged between the seating cone I (21) and the seating cone II (22) and is connected to the pressure chamber II (61); the pressure passage changes the hydraulic pressure difference formed by the pressure chamber I and the pressure chamber II on the piston to push the piston to move up or down.

2. The multi-ball controlled one-way valve according to claim 1, wherein The pressure passage I includes a diversion hole I (52) and a diversion channel I (53), the diversion hole I (52) is arranged above the seating cone II (22) and is communicated with the pressure chamber I (51) through the diversion channel I (53) arranged along the gap between the liquid control ball seat (2) and the bushing (4); the pressure passage II includes a diversion hole II (62) and a diversion channel II (63), the diversion hole II (62) is arranged between the seating cone I (21) and the seating cone II (22) and is communicated with the pressure chamber II (61) through the diversion channel II (63) arranged along the gap between the bushing (4) and the connecting cylinder (3).

3. The multi-ball controlled one-way valve according to claim 1, wherein The seating cone I (21) is a diversion groove cone surface.

4. The multi-ball controlled one-way valve according to claim 1, characterized in that, The piston includes an upper piston (5) and a lower piston (6), which are connected by screws, and the cross-sectional area of the first flange located on the upper piston (5) is smaller than the cross-sectional area of the second flange located on the lower piston (6).

5. The multi-ball controlled one-way valve according to claim 4, characterized in that, A pressure balance hole (55) is arranged at the connection of the upper piston (5) and the lower piston (6), and the pressure balance hole (55) connects the inner channel and the balance chamber (54).

6. The one-way valve with multi-ball control according to claim 1, wherein, When the inner channel is closed, the maximum upward movement distance of the piston corresponds to the upward movement distance when the piston releases the restriction on the valve flap mechanism (9).

7. The multi-ball controlled one-way valve according to claim 1, characterized in that, In the open state of the one-way valve, the piston restricts the valve flap mechanism (9) between the piston and the lower joint (10), and after the piston moves upward, the valve flap mechanism (9) plugs the lower end of the inner channel of the one-way valve to close the one-way valve.

8. The one-way valve with multi-ball control according to claim 4, characterized in that, The lower end of the said lower piston (6) includes a third flange.

9. The one-way valve with multi-ball control according to claim 8, wherein, The said one-way valve further includes a locking mechanism disposed above and abutted against the valve flap mechanism (9), and the said locking mechanism includes a locking claw (8), and the locking claw (8) is engaged with the third flange on the lower piston (6).

10. A multi-ball controlled one-way valve as claimed in claim 9, characterized in that, The said locking mechanism includes an adjusting ring (7) for adjusting the locking force of the locking claw (8), and the adjusting ring (7) is installed on the locking claw (8).

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