Shock-resistant large-flow safety valve

Abstract

The invention relates to the technical field of pressure relief of rock burst roadway hydraulic supports, in particular to an anti-impact large-flow safety valve which comprises a valve body and a valve element, the valve element comprises a first-section valve element body and a fourth-section valve element body, a third-section valve element body is arranged on the rear side of the first-section valve element body, and the diameter of the third-section valve element body is larger than that of the first-section valve element body. An annular cavity is formed among the annular face, the fourth section of valve element and the valve body, a first communication hole communicated with the liquid inlet channel is formed in the valve element, and the first communication hole is communicated with the annular cavity through a second communication hole. Compared with the prior art, the spring used by the safety valve of 1000L / min in the conventional design can meet the use requirement of the safety valve of 4000L / min, the dynamic characteristic is good, and the safety coefficient of the valve core is large; the impact damage of the valve core can be avoided; the problem of sealing failure caused by the fact that high-pressure fluid washes the sealing ring is solved; the spring is provided with a guide section for guiding, and the dynamic characteristic is good; liquid is directly discharged, the liquid discharging speed is high, and people are prevented from being hurt by traditional horizontal injection.

Description

Technical Field

[0001] The invention relates to the technical field of pressure relief of hydraulic supports in rock burst tunnels, and in particular to an anti-shock large-flow safety valve. Background Art

[0002] With the increase of mining depth, disasters such as rock burst occur more frequently. Due to its suddenness and strong destructiveness, rock burst poses a major threat to the safety of miners, tunnel stability and the integrity of mining equipment. As an anti-bumping device for maintaining tunnel stability and protecting personnel and equipment from rock burst, the reliability and safety of hydraulic supports are very important. The basic principle of anti-bumping of hydraulic supports is that when the hydraulic pressure in the hydraulic column is greater than the opening pressure of the safety valve, the safety valve will discharge fluid to release pressure to avoid damage to the column and protect the constant resistance of the column support. However, due to the characteristics of rock burst, the destructive pressure is generally reached within tens of milliseconds. Therefore, unique requirements are put forward for the reliability, stability, rapidity, sensitivity, displacement and other characteristics of the safety valve.

[0003] In the prior art, the displacement of the safety valve is very small compared to the displacement of the hydraulic column when the impact ground pressure occurs. If the displacement of the safety valve is forcibly increased, the overall size of the safety valve will be greatly increased, and the demand for spring stiffness will also be greatly increased. In addition, generally, multiple overflow holes are drilled on the hollow valve core, and a discharge port is set at the corresponding position of the valve body to meet the large flow demand. At the same time, a sealing ring is used to seal between the discharge port and the valve core, such as Chinese patents CN205990924U, CN205990927U, and CN2937588Y. In this way, when the hydraulic column is discharged when the impact ground pressure occurs, the high-pressure, fast, and large-flow liquid flushing can easily cause the seal to fail, resulting in poor reliability of the safety valve. There are also some other forms of safety valves, such as:

[0004] Chinese patent CN104500111B discloses a two-stage opening type large flow safety valve. When a small flow is discharged, the second-stage safety valve is opened. When the pressure is too high, the valve core is opened under the action of the pressure difference to discharge a large flow, thereby realizing a large flow discharge. It is not difficult for a person skilled in the art to find that the opening pressure when opening a large flow discharge is not the same as the opening pressure when opening a small flow discharge, or in other words, the opening of the safety valve has a certain hysteresis to the incoming pressure, and the rapidity and sensitivity are poor. It is obviously not very superior when facing the impact ground pressure that reaches the breaking pressure within tens of milliseconds, as shown in the background technology, it is suitable for relatively soft old top pressure. Secondly, when the safety valve is opened quickly, the valve core and the valve body of the safety valve will produce impact at the vent hole, which is very easy to cause the safety valve structure to be damaged, and the reliability is poor. In addition, in the safety valve, when a large flow is opened to discharge, the vibration of the spring is serious, the pressure fluctuates seriously, and the stability of the valve core is poor.

[0005] Chinese patent CN101539025A discloses a large flow safety valve, whose technical solution adopts a direct-acting structure. When the flow rate is several thousand liters per minute, the size and stiffness of the pressure spring will become very large, and the increase in the spring stiffness will further lead to severe pressure fluctuations and severe valve core vibration when the safety valve is opened, resulting in poor dynamic characteristics, increased starting pressure of the safety valve, and poor sensitivity.

[0006] Chinese patent CN206368986U discloses a differential safety valve, the working principle of which is: when the pressure increases to a level greater than the elastic force of the second spring but less than the elastic force of the first spring, the high-pressure gas / liquid flows from the gap through the pressure relief channel into the discharge cavity and is discharged from the discharge port; when the pressure further increases to a level greater than the elastic force of the first spring, the first spring contracts to open the first valve core; in essence, a two-stage valve is used, and the latter stage valve needs to be opened first to discharge a large flow rate, the opening time is long, and its rapidity is poor, and when the large flow rate is opened, the larger pressure is borne by the first spring to keep the valve open, the required spring stiffness is large, and its size is also large.

[0007] Chinese patent CN202209456U discloses a differential safety valve, in which the conical surface at the front end of the valve core is pressed on the first oil hole of the valve sleeve, and the rear end of the valve core passes through the second oil hole of the valve sleeve, and the diameter of the second oil hole is slightly larger than the diameter of the first oil hole. Therefore, in the third oil hole, the oil pressure to the right of the valve core is greater than the oil pressure to the left. When the pressure difference between the pressure of the pressure oil on the valve core to the right and to the left is greater than the elastic force of the spring, the valve core moves to the right, the oil outlet T is connected to the oil inlet P, and the safety valve opens. When the pressure difference between the pressure of the pressure oil on the valve core to the right and to the left is less than the elastic force of the spring, the conical surface at the left end of the valve core presses on the first oil hole, and the safety valve is closed; therefore, in this scheme, "and the diameter of the second oil hole is slightly larger than the diameter of the first oil hole" should be understood with "the valve seat, the valve core, and the valve sleeve are all cylindrical", and the valve core slides in the sliding sleeve and cooperates with each other, and its purpose should be to meet the requirements that the cylindrical valve core can slide in the sliding sleeve and the conical surface at the front end of the valve core and the valve sleeve form a sealing fit. Summary of the invention

[0008] The present invention provides an impact-resistant large-flow safety valve, which can overcome certain defects of the prior art.

[0009] According to the present invention, an impact-resistant large-flow safety valve includes: a valve body and a valve core, the valve core is arranged inside the valve body, and is characterized in that: the valve core includes a first-section valve core and a fourth-section valve core, a third-section valve core is arranged on the rear side of the first-section valve core and on the front side of the fourth-section valve core, the diameter of the third-section valve core is larger than the diameter of the first-section valve core, and at the same time, the diameter of the third-section valve core is larger than the diameter of the fourth-section valve core and forms a radial annular surface, an annular cavity is formed between the annular surface, the fourth-section valve core and the valve body, the fourth-section valve core is in contact with the reset spring device, a first connecting hole connected to the liquid inlet channel is arranged inside the valve core, the first connecting hole is connected to the annular cavity through the second connecting hole, so that the valve core constitutes an unconventional differential valve core.

[0010] Preferably, a certain distance is provided between the second connecting hole and the annular surface, and a buffer zone for impact protection is formed in the annular cavity when the valve core is quickly opened, while ensuring that the valve core can be smoothly and completely opened; a buffer damping section is formed between the second connecting hole and the annular surface at the rear end of the fourth-section valve core, and the diameter of the buffer damping section is slightly smaller than the diameter of the fourth-section valve core. After the buffer zone is formed, the liquid in the buffer zone flows to the liquid inlet channel with greater damping, and when the valve core moves to the left, the liquid can flow into the buffer zone so that the valve core can move smoothly to the left.

[0011] Preferably, the front end of the valve body is provided with a quick-plug connector and a liquid inlet channel for quick connection with the hydraulic column pressure relief port, and a valve cavity is provided at the rear end of the liquid inlet channel inside the valve body, and the valve core is arranged in the valve cavity. When the valve is fully closed, there is a certain distance between the front end face of the first section of the valve core and the front end face of the valve cavity, so as to facilitate the liquid pressure to act on the front end face of the first section of the valve core; a plurality of liquid outlets connected with the valve cavity are provided on the circumference of the valve body, and a reset spring device is arranged at the rear end of the valve body.

[0012] Preferably, the first-section valve core, the third-section valve core and the fourth-section valve core are all capable of being slidably connected in the valve cavity, a valve core liquid inlet is provided in the center of the first-section valve core, a plurality of flow holes connected with the valve core liquid inlet are provided in the circumferential direction of the first-section valve core, a second-section valve core is provided on the rear side of the first-section valve core, a third-section valve core is provided on the rear side of the second-section valve core, the diameter of the second-section valve core is smaller than that of the first-section valve core and the third-section valve core, the second-section valve core and the valve body form a transition cavity; a first sealing ring is provided between the third-section valve core and the valve body to form a sliding seal, and a second sealing ring is provided between the fourth-section valve core and the valve body to form a sliding seal.

[0013] Preferably, the second-section valve core is connected to the first-section valve core by a transition slope, and the second-section valve core is connected to the third-section valve core by a sealing slope. An annular groove is provided on the inner wall of the valve cavity at the liquid outlet, and the front side surface of the annular groove is closer to the center of the valve core than the rear side surface. When the safety valve is closed, under the action of the reset spring device, the sealing slope and the front side edge of the annular groove contact each other to form a linear seal, thereby blocking the transition cavity and the liquid outlet.

[0014] Preferably, the minimum flow cross-section of the safety valve is the flow cross-section area of ​​the valve core liquid inlet.

[0015] Preferably, the return spring device includes a spring chamber, a spring is arranged in the spring chamber, an adjustment seat for adjusting the spring compression amount is arranged at the rear end of the spring, a spring seat is arranged at the front end of the spring, and the front end of the spring seat is in contact with the fourth valve core.

[0016] Preferably, an adjusting rod is provided in the center of the spring, one end of the adjusting rod is provided with an adjusting head through a rear end cover located at the rear end of the valve body, the adjusting rod includes a threaded section, the threaded section is matched with the adjusting seat, and the adjusting rod is driven to rotate by rotating the adjusting head, thereby further driving the adjusting seat to move forward and backward.

[0017] Preferably, the adjusting rod further comprises a guiding section, the guiding section is located at the front end of the threaded section, a guiding hole is provided at the rear end of the spring seat, and the guiding hole and the guiding section cooperate with each other to form a guiding function.

[0018] Preferably, a baffle ring is provided on the adjusting rod on the front side of the rear end cover, and a wear-resistant pad is provided between the baffle ring and the rear end cover; a U-shaped protective cover is provided on the outside of the valve body, and a sealing plug is clamped between the open end of the protective cover and the valve body. When the safety valve discharges liquid, the high-speed liquid discharged from the liquid outlet to the discharge cavity is deflected by the obstruction of the protective cover, and further breaks through the sealing plug to discharge liquid outward.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] ① The diameter of the third section of the valve core is larger than that of the first section of the valve core. A first connecting hole connected to the liquid inlet channel is provided inside the valve core. The first connecting hole is connected to the annular cavity through the second connecting hole, so that the valve core constitutes an unconventional differential valve core. The spring used in a conventionally designed 1000L / min safety valve can meet the use requirements of the 4000L / min safety valve of this application. At the same time, the pressure fluctuation is small during the opening process of the valve core, that is, the dynamic characteristics are improved. Moreover, the diameter of the fourth section of the valve core in this application is larger than the equivalent diameter, the strength is greater, and the safety factor will also be greater, so the second connecting hole can be opened while meeting the use requirements.

[0021] ② When the valve core opens quickly, a buffer zone for impact protection is formed in the annular cavity, which can avoid damage caused by impact between the valve core and the valve body while ensuring the smooth and complete opening of the valve core; at the same time, the diameter of the buffer damping section is slightly smaller than the diameter of the fourth section of the valve core. After the buffer zone is formed, the liquid in the buffer zone flows to the liquid inlet channel with greater damping. When the valve core moves to the left, the liquid can flow into the buffer zone so that the valve core can move smoothly to the left.

[0022] ③ A transition chamber is provided to reduce the damping force of the discharge, increase the flow area, and further ensure that the minimum flow section is the valve core liquid inlet.

[0023] ④ When the safety valve is closed, under the action of the reset spring device, the sealing bevel and the front side edge of the annular groove contact each other to form a line seal, blocking the transition chamber and the liquid outlet. This arrangement avoids the use of traditional sealing rings for blocking, overcomes the problem of sealing failure caused by high-pressure fluid scouring the sealing ring when the sealing ring is blocking, effectively improves the service life of the valve core, and effectively improves the reliability of the present application.

[0024] ⑤ The adjusting rod also includes a guide section, which is located at the front end of the threaded section. A guide hole is provided at the rear end of the spring seat. The guide hole and the guide section cooperate with each other to form a guiding effect. Such an arrangement makes the movement of the spring more stable, and further makes the opening of the valve core more stable and the dynamic characteristics better.

[0025] ⑥ A U-shaped protective cover is provided on the outside of the valve body, and a sealing plug is provided between the open end of the protective cover and the valve body. The setting of the sealing plug prevents dust from entering the valve cavity. When the safety valve is discharging liquid, the high-speed liquid discharged from the liquid outlet to the liquid discharge cavity is blocked by the protective cover and deflected, and further breaks the sealing plug to discharge liquid outward. The liquid outlet directly discharges liquid to increase the discharge speed. The setting of the protective cover enables high-pressure liquid to spray downward when the safety valve is opened, avoiding traditional horizontal spraying and injuring people. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the enlarged structure of part A;

[0028] Figure 3 for Figure 1 Schematic diagram of the enlarged structure of part B.

[0029] in:

[0030] 100, valve body; 101, quick-connect connector; 102, liquid inlet channel; 103, valve chamber; 104, transition chamber; 105, liquid outlet; 106, liquid discharge chamber; 107, annular chamber; 108, spring chamber; 109, rear end cover; 110, annular groove; 200, valve core; 201, first section valve core; 202, flow hole; 203, first connecting hole; 204; second connecting hole; 205, annular surface; 206, fourth section valve core; 207, first sealing Sealing ring; 208, second sealing ring; 209, sealing slope; 210, second section of valve core; 211, third section of valve core; 212, valve core liquid inlet; 213, buffer damping section; 300, reset spring device; 301, spring seat; 302, spring; 303, adjustment seat; 304, adjustment rod; 305, guide hole; 306, guide section; 307, threaded section; 308, retaining ring; 309, wear-resistant pad; 400, protective cover; 401, sealing plug. DETAILED DESCRIPTION

[0031] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0032] Example 1

[0033] like Figure 1 , 2 As shown, an impact-resistant large-flow safety valve includes a valve body 100 and a valve core 200. The valve core 200 is arranged inside the valve body 100. The valve core 200 includes a first-section valve core 201 and a fourth-section valve core 206. A third-section valve core 211 is arranged on the rear side of the first-section valve core 201 and on the front side of the fourth-section valve core 206. The diameter of the third-section valve core 211 is greater than the diameter of the first-section valve core 201. At the same time, the diameter of the third-section valve core 211 is greater than the diameter of the fourth-section valve core 206 and forms a radial annular surface 205. An annular cavity 107 is formed between the annular surface 205, the fourth-section valve core 206 and the valve body 100. The fourth-section valve core 206 is in contact with the return spring device 300. A first communicating hole 203 communicating with the liquid inlet channel 102 is arranged inside the valve core 200. The first communicating hole 203 is communicated with the annular cavity 107 through the second communicating hole 204, so that the valve core constitutes an unconventional differential valve core.

[0034] With such arrangement, the difference in liquid action area between the rear side of the third-section valve core 211 and the front side of the first-section valve core 201 is the equivalent area, and the diameter of the circle corresponding to the equivalent area is the equivalent diameter; in the prior art, the conventional differential connection is that the diameter of the third-section valve core 211 is equal to the diameter of the first-section valve core 201, then, the equivalent area will be equal to the cross-sectional area of ​​the fourth-section valve core 206, and the equivalent diameter will be equal to the diameter of the fourth-section valve core 206. Since the annular cavity 107 is connected to the valve core liquid inlet 212, the liquid pressure is equal, and the product of the equivalent area and the liquid pressure is the elastic force of the spring 302. The spring 302 can be selected using the equivalent diameter. The larger the equivalent diameter, the greater the required spring stiffness and the larger the spring size, and vice versa. Therefore, the equivalent diameter obtained according to the scheme in the prior art will be larger than the equivalent diameter in the present application, and the stiffness and size of the spring 302 selected accordingly will inevitably be larger than that in the present application. The spring selected in the request is larger, and the spring 302 in the present application has a smaller stiffness and size, so the vibration caused by the spring 302 will be smaller, and the pressure fluctuation during the opening of the valve core will be small and smoother; moreover, the diameter of the fourth-section valve core 206 in the present application is larger than the equivalent diameter, the strength is greater, and the safety factor will also be greater, and the second connecting hole 204 can be opened while meeting the use requirements. In this embodiment, four second connecting holes 204 are evenly arranged in the circumferential direction; for example, when the diameter of the third-section valve core 211 is 32.7mm, the diameter of the first-section valve core 201 is 30mm, and the diameter of the fourth-section valve core 206 is 18mm, when the spring 302 is selected according to the equivalent diameter of 13mm, the spring used for a safety valve of 1000L / min can meet the use requirements of a safety valve of 4000L / min. At the same time, the pressure fluctuation is small during the opening of the valve core, that is, the dynamic characteristics are improved.

[0035] A certain distance is set between the second communication hole 204 and the annular surface 205. When the valve core 200 is opened quickly, a buffer zone for impact protection is formed in the annular cavity 107 to avoid damage caused by the impact between the valve core 200 and the valve body 100, while ensuring that the valve core 200 is smoothly and completely opened; Figure 3 As shown, a buffer damping section 213 is formed between the second connecting hole 204 and the annular surface 205 at the front end of the fourth section valve core 206. The diameter of the buffer damping section 213 is slightly smaller than the diameter of the fourth section valve core 206. After the buffer zone is formed, the liquid in the buffer zone flows toward the liquid inlet channel 102 with greater damping. When the valve core moves to the left, the liquid can flow into the buffer zone so that the valve core can move smoothly to the left.

[0036] A quick-connect connector 101 and a liquid inlet channel 102 for quick connection to the hydraulic column pressure relief port are provided at the front end of the valve body 100. A valve cavity 103 is provided at the rear end of the liquid inlet channel 102 inside the valve body 100. The valve core 200 is arranged in the valve cavity 103. When the valve is fully closed, there is a certain distance between the front end face of the first section of the valve core 201 and the front end face of the valve cavity 103, which facilitates the liquid pressure to act on the front end face of the first section of the valve core 201; a plurality of liquid outlets 105 connected to the valve cavity 103 are provided on the circumference of the valve body 100. In this embodiment, four liquid outlets 105 are evenly provided, and the return spring device 300 is arranged at the rear end of the valve body 100.

[0037] The first valve core 201, the third valve core 211 and the fourth valve core 206 are all slidably connected in the valve cavity 103. A valve core liquid inlet 212 is provided at the center of the first valve core 201. A plurality of flow holes 202 connected to the valve core liquid inlet 212 are provided in the circumferential direction of the first valve core 201. In this embodiment, four flow holes 202 are evenly arranged. A second valve core 210 is provided at the rear side of the first valve core 201. A third valve core 211 is provided at the rear side of the second valve core 210. The diameter of the second valve core 210 is smaller than that of the first valve core 201 and the third valve core 211. The second valve core 210 is connected to the valve cavity 103. The body 100 forms a transition chamber 104. When the safety valve is opened, the flow hole 202 is connected with the transition chamber 104, and the transition chamber 104 is connected with the liquid outlet 105. The setting of the transition chamber 104 reduces the damping force and increases the flow area, which can further ensure that the minimum flow section is the valve core liquid inlet 212; a first sealing ring 207 is provided between the third section of the valve core 211 and the valve body to form a sliding seal, and a second sealing ring 208 is provided between the fourth section of the valve core 206 and the valve body to form a sliding seal. The first sealing ring 207 and the second sealing ring 208 are not affected by the scouring of large-flow and high-speed fluids, and there is no problem of scouring failure.

[0038] The second valve core 210 is connected to the first valve core 201 by a transition slope, and the second valve core 210 is connected to the third valve core 211 by a sealing slope 209. An annular groove 110 is provided on the inner wall of the valve cavity 103 at the liquid outlet 105. The front side surface of the annular groove 110 is closer to the center of the valve core 210 than the rear side surface. When the safety valve is closed, under the action of the reset spring device 300, the sealing slope 209 and the front side edge of the annular groove 110 contact each other to form a line seal, thereby blocking the transition cavity 104 and the liquid outlet 105. Such a setting avoids the use of traditional sealing rings for blocking, overcomes the problem of sealing failure caused by high-pressure fluid scouring the sealing ring when the sealing ring is blocking, effectively improves the service life of the valve core, and effectively improves the reliability of the present application.

[0039] Those skilled in the art should be aware that the displacement of the safety valve is proportional to the flow cross-sectional area. Therefore, in order to reduce the overall size of the safety valve as much as possible, the minimum flow cross-sectional area of ​​the safety valve is the flow cross-sectional area of ​​the valve core liquid inlet 212.

[0040] The return spring device 300 includes a spring chamber 108, in which a spring 302 is arranged, and an adjustment seat 303 which can adjust the compression amount of the spring 302 is arranged at the rear end of the spring 302, and a spring seat 301 is arranged at the front end of the spring 302, and the front end of the spring seat 301 is in contact with the fourth section valve core 206. With such an arrangement, the opening pressure of the safety valve can be adjusted through the adjustment seat 303.

[0041] An adjusting rod 304 is provided at the center of the spring 302. One end of the adjusting rod 304 passes through the rear end cover 109 located at the rear end of the valve body 100 and is provided with an adjusting head. The adjusting rod 304 includes a threaded section 307. The threaded section 307 is matched with the adjusting seat 303. The adjusting rod 304 is rotated by rotating the adjusting head, and the adjusting seat 303 is further driven to move forward and backward to achieve the purpose of adjusting the opening pressure of the safety valve.

[0042] The adjusting rod 304 also includes a guide section 306, which is located at the front end of the threaded section 307. A guide hole 305 is provided at the rear end of the spring seat 301. The guide hole 305 and the guide section 306 cooperate with each other to form a guiding function. This arrangement makes the movement of the spring 302 more stable, and further makes the opening of the valve core 200 more stable and has better dynamic characteristics.

[0043] A retaining ring 308 is provided on the adjusting rod 304 on the front side of the rear end cover 109, and a wear-resistant pad 309 is provided between the retaining ring 308 and the rear end cover 109; a U-shaped protective cover 400 is provided on the outside of the valve body 100, and a sealing plug 401 is clamped between the open end of the protective cover 400 and the valve body 100. The setting of the sealing plug 401 prevents dust from entering the valve cavity 103. When the safety valve is discharging liquid, the high-speed liquid discharged from the liquid outlet 105 to the liquid discharge cavity 106 is turned after being blocked by the protective cover 400, and further breaks through the sealing plug 401 to discharge liquid outwardly. The liquid outlet directly discharges liquid to increase the discharge speed. The setting of the protective cover 400 enables high-pressure liquid to spray downward when the safety valve is opened, avoiding traditional horizontal spraying and injuring people.

[0044] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. An impact-resistant large-flow safety valve, comprising: A valve body (100) and a valve core (200), wherein the valve core (200) is arranged inside the valve body (100), and is characterized in that: the valve core (200) includes a first section of the valve core (201) and a fourth section of the valve core (206), a third section of the valve core (211) is arranged at the rear side of the first section of the valve core (201) and at the front side of the fourth section of the valve core (206), the diameter of the third section of the valve core (211) is larger than the diameter of the first section of the valve core (201), and at the same time, the diameter of the third section of the valve core (211) is larger than the diameter of the fourth section of the valve core (206). 6) and forming a radial annular surface (205); an annular cavity (107) is formed between the annular surface (205), the fourth valve core (206) and the valve body (100); the fourth valve core (206) is in contact with the return spring device (300); a first connecting hole (203) connected to the liquid inlet channel (102) is provided inside the valve core (200); the first connecting hole (203) is connected to the annular cavity (107) via the second connecting hole (204), so that the valve core constitutes an unconventional differential valve core.

2. The impact-resistant large-flow safety valve according to claim 1 is characterized in that: A certain distance is provided between the second connecting hole (204) and the annular surface (205); when the valve core (200) is opened quickly, a buffer zone for impact protection is formed in the annular cavity (107); and at the same time, the valve core (200) can be ensured to be smoothly and completely opened; a buffer damping section (213) is formed between the second connecting hole (204) at the rear end of the fourth section valve core (206) and the annular surface (205); the diameter of the buffer damping section (213) is slightly smaller than the diameter of the fourth section valve core (206); after the buffer zone is formed, the liquid in the buffer zone flows toward the liquid inlet channel (102) with greater damping; when the valve core moves to the left, the liquid can flow into the buffer zone so that the valve core can move smoothly to the left.

3. The impact-resistant large-flow safety valve according to claim 1 is characterized in that: The front end of the valve body (100) is provided with a quick-connect connector (101) and a liquid inlet channel (102) for quick connection with the hydraulic column pressure relief port; the rear end of the liquid inlet channel (102) inside the valve body (100) is provided with a valve cavity (103); the valve core (200) is arranged in the valve cavity (103); when the valve is fully closed, there is a certain distance between the front end face of the first section of the valve core (201) and the front end face of the valve cavity (103), so that the liquid pressure acts on the front end face of the first section of the valve core (201); a plurality of liquid outlets (105) in communication with the valve cavity (103) are provided on the circumference of the valve body (100); and a return spring device (300) is arranged at the rear end of the valve body (100).

4. The impact-resistant large-flow safety valve according to claim 1 is characterized in that: The first valve core (201), the third valve core (211) and the fourth valve core (206) are all capable of being slidably connected in the valve cavity (103); a valve core liquid inlet (212) is provided at the center of the first valve core (201); a plurality of flow holes (202) in communication with the valve core liquid inlet (212) are provided in the circumferential direction of the first valve core (201); a second valve core (210) is provided at the rear side of the first valve core (201); and the second valve core (211) is provided at the rear side of the second valve core (206). 10) is provided with a third valve core (211) at the rear side, the diameter of the second valve core (210) is smaller than the first valve core (201) and the third valve core (211), the second valve core (210) and the valve body (100) form a transition chamber (104); a first sealing ring (207) is provided between the third valve core (211) and the valve body to form a sliding seal, and a second sealing ring (208) is provided between the fourth valve core (206) and the valve body to form a sliding seal.

5. The impact-resistant large-flow safety valve according to claim 4 is characterized in that: The second valve core (210) is connected to the first valve core (201) by a transition slope, and the second valve core (210) is connected to the third valve core (211) by a sealing slope (209). An annular groove (110) is provided on the inner wall of the valve cavity (103) at the liquid outlet (105), and the front side surface of the annular groove (110) is closer to the center of the valve core (210) than the rear side surface. When the safety valve is closed, under the action of the reset spring device (300), the sealing slope (209) and the front side edge of the annular groove (110) contact each other to form a line seal, thereby blocking the transition cavity (104) and the liquid outlet (105).

6. The impact-resistant large flow safety valve according to claim 1, characterized in that: The minimum flow cross section of the safety valve is the flow cross section area of ​​the valve core liquid inlet (212).

7. The impact-resistant large-flow safety valve according to claim 1 is characterized in that: The return spring device (300) comprises a spring chamber (108), a spring (302) is arranged in the spring chamber (108), an adjustment seat (303) capable of adjusting the compression amount of the spring (302) is arranged at the rear end of the spring (302), a spring seat (301) is arranged at the front end of the spring (302), and the front end of the spring seat (301) is in contact connection with the fourth valve core (206).

8. The impact-resistant large-flow safety valve according to claim 7 is characterized in that: An adjusting rod (304) is provided at the center of the spring (302). One end of the adjusting rod (304) passes through a rear end cover (109) located at the rear end of the valve body (100) and is provided with an adjusting head. The adjusting rod (304) includes a threaded section (307). The threaded section (307) is matched with the adjusting seat (303). The adjusting rod (304) is driven to rotate by rotating the adjusting head, and the adjusting seat (303) is further driven to move forward and backward.

9. The impact-resistant large-flow safety valve according to claim 8, characterized in that: The adjusting rod (304) further comprises a guiding section (306), wherein the guiding section (306) is located at the front end of the threaded section (307), and a guiding hole (305) is provided at the rear end of the spring seat (301), wherein the guiding hole (305) and the guiding section (306) cooperate with each other to form a guiding function.

10. The impact-resistant large-flow safety valve according to claim 8, characterized in that: A retaining ring (308) is provided on the regulating rod (304) on the front side of the rear end cover (109), and a wear-resistant pad (309) is provided between the retaining ring (308) and the rear end cover (109); a U-shaped protective sleeve (400) is provided on the outer side of the valve body (100), and a sealing plug (401) is clamped between the open end of the protective sleeve (400) and the valve body (100); when the safety valve is discharging liquid, high-speed liquid discharged from the liquid outlet (105) to the liquid discharge cavity (106) is deflected by the blocking of the protective sleeve (400), and further breaks through the sealing plug (401) to discharge liquid outward.

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