Straight-through type pressure release valve

Abstract

The invention belongs to the technical field of pressure control, and particularly relates to a straight-through type pressure release valve which comprises a main valve cylinder, drainage equipment is arranged at the top of the inner wall of the main valve cylinder, pressure release equipment is arranged in the middle of the inner wall of the main valve cylinder, and drainage equipment is arranged at the bottom of the main valve cylinder. The drainage equipment comprises a traction sliding barrel, and the inner wall of the traction sliding barrel is rotationally connected with a guide sliding barrel through a clamping groove. When the device is used for working, fine adjustment can be carried out by screwing the rotating nut, the hydraulic pressure of the discharged water body is changed, the water body always moves from top to bottom, and the water outlets in the drainage equipment and the pressure relief equipment are uniformly distributed in the circumference, so that the water body flows in the device; the hydraulic action borne by the device is kept in a balanced state all the time, so that it is guaranteed that the device is firm and stable after being vertically installed, and the problem that the device cannot be stably installed due to uneven internal hydraulic stress is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of pressure control, in particular to a straight-through pressure relief valve. Background Art

[0002] Pressure relief valves are used in various piping systems. They can be opened and closed automatically according to the working pressure of the system. They are usually installed on equipment or pipelines in closed systems to protect the safety of the system. When the pressure in the equipment or pipeline exceeds the set pressure of the pressure relief valve, it will automatically open to release pressure, ensuring that the pressure of the medium in the equipment and pipeline is below the set pressure, protecting the equipment and pipeline and preventing accidents.

[0003] The valve core inside the straight-through pressure relief valve usually performs adaptive adjustment according to the pressure of the incoming liquid to ensure that the hydraulic pressure at the discharge port is always a relatively stable value. However, the pressure at the inlet of the valve body is usually greater than the pressure at the outlet. In this way, the force on the valve body will be very unbalanced, causing the valve body to become loose and unstable after long-term use, which may lead to safety hazards. Therefore, improvements are needed. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention solves the technical problems by adopting the following technical solutions: a straight-through pressure relief valve, comprising a main valve cylinder, a flow guide device is arranged at the top of the inner wall of the main valve cylinder, a pressure relief device is arranged at the middle of the inner wall of the main valve cylinder, and a flow discharge device is arranged at the bottom of the main valve cylinder;

[0005] The drainage device comprises a traction slide cylinder, the inner wall of which is rotatably connected to a guide slide cylinder through a slot, the top of the inner wall of the guide slide cylinder is fixedly connected to a water pipe, the outer surface of the traction slide cylinder is evenly provided with bent traction rods, one end of the bent traction rod away from the traction slide cylinder is fixedly connected to a rotating nut, the inner wall of the rotating nut is connected to the threaded groove on the upper part of the outer surface of the main valve cylinder, and the rotating nut is driven to rotate clockwise to push the drainage device downward as a whole;

[0006] The lower part of the outer surface of the guide slide is rotatably connected with a drainage slide shell, and a spring washer is fixedly connected at the axis center of the inner wall of the drainage slide shell. The middle part of the spring washer is always fixed on the inner wall of the main valve cylinder. As the traction slide and the drainage slide shell move, both upper and lower sides thereof will cause resistance to the traction slide and the drainage slide shell; a pressure-sensing inner cylinder is fixedly connected at the axis center of the bottom of the inner cavity of the guide slide, and the pressure-sensing inner cylinder can monitor the internal hydraulic pressure of the guide slide through the round-headed push rod at the top, and a one-way drainage component is evenly arranged at the lower part of the inner cavity of the guide slide;

[0007] The pressure relief device includes a hollow cylindrical shell, the inner cavity of the hollow cylindrical shell is evenly provided with plug-in tubes through the socket, the inner wall of the hollow cylindrical shell is evenly provided with detectors, and plug-in inner plates are symmetrically provided on the front and rear sides of the inner cavity of the detector. The detector performs hydraulic detection through the plug-in inner plates that can be pushed on both sides, and vertical grooves adapted to the plug-in inner plates are opened on both sides of the plug-in tube.

[0008] Furthermore, an external bottom plate is evenly arranged at the bottom of the outer surface of the guide slide, a drainage plug is fixedly connected to the side of the upper surface of the external bottom plate away from the guide slide, the outer surface of the drainage plug is slidably connected to the inner wall of the plug tube, and the side of the plug inner plate away from the detector extends to the inside of the plug tube through a notch. The inner wall of the rotating nut is threadedly connected to the top of the outer surface of the main valve cylinder through a thread groove, the lower part of the outer surface of the traction slide is slidably connected to the top of the inner wall of the main valve cylinder, the outer surface of the drainage slide is slidably connected to the inner wall of the main valve cylinder, the top of the spring washer is fixedly connected to the bottom of the traction slide, and the middle part of the outer surface of the spring washer is fixedly connected to the inner wall of the main valve cylinder. The outer surface of the guide slide is slidably connected to the axis center of the inner wall of the hollow cylinder shell, the number of the drainage pipes is six, the number of the detectors is six, the upper and lower sides of the detectors are fixedly connected to the inner wall of the hollow cylinder shell, the outer surface of the plug tube is fixedly connected to the inner cavity of the hollow cylinder shell, and the middle part of the inner wall of the main valve cylinder is fixedly connected to the outer surface of the hollow cylinder shell.

[0009] Furthermore, the one-way drainage component includes a sliding sleeve, the inner cavity of the sliding sleeve is uniformly provided with through grooves, under normal circumstances, the through grooves of the sliding sleeve are located inside the guide slide, the end of the sliding sleeve away from the guide slide is fixedly connected to a docking pad, the end of the docking pad away from the sliding sleeve is fixedly connected to a spring pressure rod, and the end of the outer surface of the sliding sleeve away from the spring pressure rod is sleeved with a waterproof cushion, which can prevent liquid from leaking out through the gap between the sliding sleeve and the guide slide. There are four sliding sleeves, the outer surface of the sliding sleeve is slidably connected to the inner cavity of the guide slide, the end of the spring pressure rod away from the sliding sleeve is slidably connected to the inner wall of the main valve cylinder, and the side of the waterproof cushion close to the spring pressure rod is pressed against the inner wall of the guide slide.

[0010] Furthermore, the drainage device includes a rotating bottom cylinder, a drainage groove is symmetrically provided in the middle of the inner cavity of the rotating bottom cylinder, a switching cylinder is rotatably connected to the bottom of the outer surface of the rotating bottom cylinder, a docking groove is symmetrically provided in the inner cavity of the switching cylinder, and the docking groove has the same shape as the drainage groove. When the two are successfully docked, the drainage device can normally relieve pressure and discharge liquid. Pressure-bearing air bags are symmetrically provided on both sides of the inner wall of the switching cylinder, and the inner cavity of the pressure-bearing air bag is fixedly connected to a pressure-sensitive plate through a thrust rod. The number of the pressure-bearing air bags is two, the outer surface of the pressure-bearing air bag is slidably connected to the inner wall of the switching cylinder, the outer surface of the pressure-sensitive plate is fixedly connected to one side of the outer surface of the switching cylinder, and the upper surface of the rotating bottom cylinder is fixedly connected to the bottom end of the main valve cylinder. The number of the drainage grooves is two, the number of the docking grooves is two, and the docking grooves extend to the upper and lower sides of the outer surface of the switching cylinder, and the axis of the top of the rotating bottom cylinder extends to the bottom of the inner cavity of the main valve cylinder.

[0011] The beneficial effects of the present invention are as follows:

[0012] 1. When the device is used for work, the guide slide cylinder that passes high-pressure water will divert the water to the pressure relief device at the bottom to achieve a pressure reduction effect, and can be fine-tuned by screwing the rotating nut to change the hydraulic pressure of the discharged water. Since the water always moves from top to bottom, and the drainage ports inside the drainage device and the pressure relief device are evenly distributed in a circle, when the water flows inside the device, the hydraulic pressure on the device always remains balanced, thereby ensuring that the device is relatively firm and stable after vertical installation, avoiding the problem of uneven internal hydraulic force and inability to install stably.

[0013] 2. The device performs drainage work through the drainage plug that slides out of the plug-in tube. When the drainage plug does not completely slide out of the plug-in tube, part of the hydraulic pressure will act on the inner wall of the plug-in tube, thereby causing the pressure surface of the plug-in inner plate to be subjected to the hydraulic pressure, so that the detector can monitor the force of the divided pressure, and then adjust the rotating nut to achieve pressure reduction while ensuring that the water pressure does not exceed the pressure range of the pressure relief device, thereby preventing the pressure relief device from being damaged due to the hydraulic pressure that exceeds its own capacity.

[0014] 3. A one-way drainage component is installed at the bottom of the guide slide to ensure that the water discharged from the guide slide will not flow back into the guide slide due to insufficient supply pressure, causing water pollution. The one-way drainage component can slide synchronously along the inner wall of the main valve cylinder with the vertical movement of the guide slide, so the one-way drainage component can actually have a limiting effect on the guide slide, thereby avoiding the guide slide from sliding too far, causing the drainage plug to be completely detached from the inside of the plug-in tube; preventing the plug-in tube and the drainage plug from being misaligned, resulting in the drainage plug being unable to be reinserted into the plug-in tube.

[0015] 4. The drainage device can be controlled by the operator to completely misalign the drainage groove and the docking groove, close the valve body, achieve the water sealing effect, and realize the function of blocking the water body. When draining, if the water pressure is too high, part of the water in the inner cavity of the switching drum will squeeze the pressurized air bags on both sides, thereby pushing the internal rod to act on the pressure-sensitive plate, and then detect the actual water storage volume inside the switching drum. If the water storage volume is large, it is necessary to reduce the pressure in time to avoid the problem of excessive water accumulation inside the main valve cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a front view of the present invention;

[0017] Figure 2 is a cross-sectional view of the main valve cylinder of the present invention;

[0018] Figure 3 is a cross-sectional view of the drainage device of the present invention;

[0019] Figure 4 is a cross-sectional view of the pressure relief device of the present invention;

[0020] Figure 5 It is a structural schematic diagram of the one-way drainage component of the present invention;

[0021] Figure 6 is a cross-sectional view of the drainage device of the present invention;

[0022] Figure 7 It is a cross-sectional view of the drainage device after the butt cut groove and the drainage groove of the present invention are butt-jointed.

[0023] In the figure: 1. drainage equipment; 11. traction slide; 12. guide slide; 13. water pipe; 14. bent traction rod; 15. rotating nut; 16. drainage slide shell; 17. pressure-sensitive inner cylinder; 18. spring washer; 2. main valve cylinder; 3. pressure relief equipment; 31. hollow cylinder shell; 32. plug-in tube; 33. detector; 34. plug-in inner plate; 35. external bottom plate; 36. drainage plug-in tube; 5. one-way drainage component; 51. sliding shell; 52. through-cut groove; 53. waterproof cushion; 54. docking pad; 55. spring pressure rod; 4. drainage equipment; 41. rotating bottom cylinder; 42. drainage groove; 43. switching rotating cylinder; 44. docking groove; 45. pressure airbag; 46. pressure-sensitive plate. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0025] Example 1, please refer to Figure 1-Figure 4 The present invention provides a technical solution: a straight-through pressure relief valve, comprising a main valve cylinder 2, a flow guide device 1 is arranged at the top of the inner wall of the main valve cylinder 2, a pressure relief device 3 is arranged at the middle of the inner wall of the main valve cylinder 2, and a flow discharge device 4 is arranged at the bottom of the main valve cylinder 2;

[0026] The drainage device 1 includes a traction slide 11, the inner wall of the traction slide 11 is rotatably connected to a guide slide 12 through a slot, the top of the inner wall of the guide slide 12 is fixedly connected to a water pipe 13, the outer surface of the traction slide 11 is evenly provided with a bent traction rod 14, and the end of the bent traction rod 14 away from the traction slide 11 is fixedly connected to a rotating nut 15, the inner wall of the rotating nut 15 is connected to the threaded groove on the upper part of the outer surface of the main valve cylinder 2, and the rotating nut 15 is driven to rotate clockwise to push the drainage device 1 downward as a whole;

[0027] The lower part of the outer surface of the guide slide 12 is rotatably connected with a drainage slide shell 16, and a spring washer 18 is fixedly connected to the axis of the inner wall of the drainage slide shell 16. The middle part of the spring washer 18 is always fixed on the inner wall of the main valve cylinder 2. As the traction slide 11 and the drainage slide shell 16 move, the upper and lower sides thereof will cause resistance to the traction slide 11 and the drainage slide shell 16; a pressure-sensing inner cylinder 17 is fixedly connected to the axis of the bottom of the inner cavity of the guide slide 12, and the pressure-sensing inner cylinder 17 can monitor the internal hydraulic pressure of the guide slide 12 through the round-headed push rod at the top, and the lower part of the inner cavity of the guide slide 12 is evenly provided with a one-way drainage component 5;

[0028] The pressure relief device 3 includes a hollow cylindrical shell 31, the inner cavity of the hollow cylindrical shell 31 is evenly provided with plug-in tubes 32 through the through-sockets, the inner wall of the hollow cylindrical shell 31 is evenly provided with detectors 33, and plug-in inner plates 34 are symmetrically provided on the front and rear sides of the inner cavity of the detector 33. The detector 33 performs hydraulic detection through the plug-in inner plates 34 that can be pushed on both sides, and vertical grooves adapted to the plug-in inner plates 34 are opened on both sides of the plug-in tube 32.

[0029] The bottom of the outer surface of the guide slide 12 is evenly provided with an external bottom plate 35, and a drainage plug 36 is fixedly connected to the side of the upper surface of the external bottom plate 35 away from the guide slide 12. The outer surface of the drainage plug 36 is slidably connected to the inner wall of the plug tube 32, and the side of the plug inner plate 34 away from the detector 33 extends to the inside of the plug tube 32 through a notch. The inner wall of the rotating nut 15 is threadedly connected to the top of the outer surface of the main valve cylinder 2 through a thread groove, the lower part of the outer surface of the traction slide 11 is slidably connected to the top of the inner wall of the main valve cylinder 2, the outer surface of the drainage slide shell 16 is slidably connected to the inner wall of the main valve cylinder 2, the top of the spring washer 18 is fixedly connected to the bottom of the traction slide 11, and the middle part of the outer surface of the spring washer 18 is fixedly connected to the inner wall of the main valve cylinder 2. The outer surface of the guide slide 12 is slidably connected to the axis center of the inner wall of the hollow cylinder shell 31, the number of drainage plugs 36 is six, the number of detectors 33 is six, the upper and lower sides of the detectors 33 are fixedly connected to the inner wall of the hollow cylinder shell 31, the outer surface of the plug tube 32 is fixedly connected to the inner cavity of the hollow cylinder shell 31, and the middle part of the inner wall of the main valve cylinder 2 is fixedly connected to the outer surface of the hollow cylinder shell 31.

[0030] When using the device to work, the water pipe 13 at the top is fixedly connected to the drain port of the pipe body, and then the water passes into the interior of the guide slide 12 under the action of water pressure, and is first discharged to the upper part of the pressure relief device 3 through the one-way drainage component 5. After adjustment, the water can be discharged downward through the pressure relief device 3 and the pressure is reduced, and then the depressurized water is discharged from the drainage device 4.

[0031] When performing pressure regulation, the operator rotates the rotating nut 15 clockwise from the outside. When the rotating nut 15 is spirally advanced downward along the outer surface of the main valve cylinder 2, the rotating nut 15 drives the traction slide 11 to rotate downward and advance the guide slide 12 through the bent traction rod 14, so that the guide slide 12 gradually slides down along the inner wall of the main valve cylinder 2. At this time, the drainage plug 36 fully inserted into the plug tube 32 will slide down with the guide slide 12, and then the water will be discharged downward through the groove through which the drainage plug 36 slides out.

[0032] When the drain plug 36 is draining, since part of the pipe body of the drain plug 36 is still located inside the plug tube 32, the water pressure will cause a hydraulic effect on the inner wall of the plug tube 32. At this time, the water pressure will squeeze the side of the plug inner plate 34, so that the pressure of the water inside the hollow cylinder shell 31 is detected by the detector 33. Combined with the pressure measurement effect of the pressure-sensitive inner cylinder 17, the pressure reduction amplitude of the device can be determined, and then the water pressure intensity discharged by the drain plug 36 can be adjusted by rotating the nut 15 with the knob.

[0033] Example 2, please refer to Figure 1-Figure 7The present invention provides a technical solution: on the basis of the first embodiment, the one-way drainage component 5 comprises a sliding housing 51, the inner cavity of the sliding housing 51 is uniformly provided with through grooves 52, under normal circumstances, the through grooves 52 of the sliding housing 51 are located inside the guide slide 12, the end of the sliding housing 51 away from the guide slide 12 is fixedly connected with a docking pad 54, the end of the docking pad 54 away from the sliding housing 51 is fixedly connected with a spring pressure rod 55, and the end of the outer surface of the sliding housing 51 away from the spring pressure rod 55 is sleeved with a waterproof cushion 53, which can prevent liquid from leaking out through the gap between the sliding housing 51 and the guide slide 12. There are four sliding housings 51, the outer surface of the sliding housing 51 is slidably connected with the inner cavity of the guide slide 12, the end of the spring pressure rod 55 away from the sliding housing 51 is slidably connected with the inner wall of the main valve cylinder 2, and the side of the waterproof cushion 53 close to the spring pressure rod 55 is pressed against the inner wall of the guide slide 12.

[0034] The drainage device 4 includes a rotating bottom cylinder 41, a drainage groove 42 is symmetrically provided in the middle of the inner cavity of the rotating bottom cylinder 41, a switching cylinder 43 is rotatably connected to the bottom of the outer surface of the rotating bottom cylinder 41, a docking groove 44 is symmetrically provided in the inner cavity of the switching cylinder 43, and the docking groove 44 has the same shape as the drainage groove 42. When the two are successfully docked, the drainage device 4 can normally release pressure and discharge liquid, and pressure-bearing air bags 45 are symmetrically provided on both sides of the inner wall of the switching cylinder 43, and the inner cavity of the pressure-bearing air bag 45 is fixedly connected to a pressure-sensitive plate 46 through a thrust rod. There are two pressure-bearing air bags 45, the outer surface of the pressure-bearing air bag 45 is slidably connected to the inner wall of the switching cylinder 43, the outer surface of the pressure-sensitive plate 46 is fixedly connected to one side of the outer surface of the switching cylinder 43, and the upper surface of the rotating bottom cylinder 41 is fixedly connected to the bottom end of the main valve cylinder 2. There are two drainage grooves 42 and two docking grooves 44 , and the docking grooves 44 extend to the upper and lower sides of the outer surface of the switching cylinder 43 , and the axis of the top of the rotating bottom cylinder 41 extends to the bottom of the inner cavity of the main valve cylinder 2 .

[0035] When the water inside the guide slide 12 is discharged from the through groove 52 of the sliding shell 51, the sliding shell 51 is first pushed toward the outside of the guide slide 12. At this time, the through groove 52 connects the inside and outside of the guide slide 12, and the waterproof cushion 53 is further compressed to prevent the water from being discharged through the gap between the guide slide 12 and the sliding shell 51. After the sliding shell 51 is pushed forward and slid, the docking pad 54 also compresses the spring pressure rod 55 under the action of thrust. When the water pipe 13 is under-pressured, the spring pressure rod 55 will push the sliding shell 51 toward the inside of the guide slide 12, thereby preventing the discharged water pressure from flowing back into the inside of the water pipe 13, thereby playing a role of automatic isolation.

[0036] The operator can rotate the bottom switching drum 43 around the rotating bottom drum 41 to connect the drainage groove 42 with the docking groove 44. Figure 7As shown, at this time, the drainage device 4 performs drainage work normally, and when the drainage stops, the rotary drum 43 is rotated and switched to make the drainage groove 42 and the docking groove 44 completely displaced, as shown in FIG. Figure 6 As shown, the drainage groove 42 is blocked, thereby avoiding water leakage in the equipment. During drainage, if the water pressure is too high, part of the water in the inner cavity of the switching drum 43 will squeeze the pressurized air bags 45 on both sides, thereby pushing the internal rod to act on the pressure-sensitive plate 46, and then detecting the actual water storage volume inside the switching drum 43.

[0037] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A straight-through pressure relief valve, comprising a main valve cylinder (2), a flow guide device (1) is arranged at the top of the inner wall of the main valve cylinder (2), a pressure relief device (3) is arranged at the middle of the inner wall of the main valve cylinder (2), and a flow discharge device (4) is arranged at the bottom of the main valve cylinder (2), characterized in that: The drainage device (1) comprises a traction slide (11), the inner wall of the traction slide (11) is rotatably connected to a guide slide (12) via a slot, the top of the inner wall of the guide slide (12) is fixedly connected to a water pipe (13), the outer surface of the traction slide (11) is evenly provided with bent traction rods (14), and one end of the bent traction rod (14) away from the traction slide (11) is fixedly connected to a rotating nut (15); The lower part of the outer surface of the guide slide cylinder (12) is rotatably connected to a drainage slide shell (16), the inner wall of the drainage slide shell (16) is fixedly connected to a spring washer (18) at the axis center, the bottom of the inner cavity of the guide slide cylinder (12) is fixedly connected to a pressure-sensitive inner cylinder (17) at the axis center, and the lower part of the inner cavity of the guide slide cylinder (12) is evenly provided with a one-way drainage component (5); The pressure relief device (3) comprises a hollow cylindrical shell (31), the inner cavity of the hollow cylindrical shell (31) is evenly provided with plug-in tubes (32) through a through-hole, the inner wall of the hollow cylindrical shell (31) is evenly provided with detectors (33), and plug-in inner plates (34) are symmetrically provided on the front and rear sides of the inner cavity of the detector (33).

2. The straight-through pressure relief valve according to claim 1, characterized in that: An external bottom plate (35) is evenly arranged at the bottom of the outer surface of the guide slide (12); a drainage plug (36) is fixedly connected to the upper surface of the external bottom plate (35) at a side away from the guide slide (12); the outer surface of the drainage plug (36) is slidably connected to the inner wall of the plug-in tube (32); and the side of the plug-in inner plate (34) away from the detector (33) extends to the interior of the plug-in tube (32) through a notch.

3. The straight-through pressure relief valve according to claim 2, characterized in that: The inner wall of the rotating nut (15) is threadedly connected to the top of the outer surface of the main valve cylinder (2) through a thread groove, the lower part of the outer surface of the traction slide (11) is slidably connected to the top of the inner wall of the main valve cylinder (2), the outer surface of the drainage slide shell (16) is slidably connected to the inner wall of the main valve cylinder (2), the top of the spring washer (18) is fixedly connected to the bottom of the traction slide (11), and the middle part of the outer surface of the spring washer (18) is fixedly connected to the inner wall of the main valve cylinder (2).

4. The straight-through pressure relief valve according to claim 3, characterized in that: The outer surface of the guide slide (12) is slidably connected to the axis of the inner wall of the hollow cylinder shell (31), the number of the drainage plugs (36) is six, the number of the detectors (33) is six, the upper and lower sides of the detectors (33) are fixedly connected to the inner wall of the hollow cylinder shell (31), the outer surface of the plug tube (32) is fixedly connected to the inner cavity of the hollow cylinder shell (31), and the middle part of the inner wall of the main valve cylinder (2) is fixedly connected to the outer surface of the hollow cylinder shell (31).

5. The straight-through pressure relief valve according to claim 1, characterized in that: The one-way drainage component (5) comprises a sliding shell (51), the inner cavity of the sliding shell (51) is evenly provided with through grooves (52), one end of the sliding shell (51) away from the guide slide cylinder (12) is fixedly connected to a docking pad (54), one end of the docking pad (54) away from the sliding shell (51) is fixedly connected to a spring pressure rod (55), and one end of the outer surface of the sliding shell (51) away from the spring pressure rod (55) is sleeved with a waterproof cushion (53).

6. The straight-through pressure relief valve according to claim 5, characterized in that: The number of the sliding shells (51) is four, the outer surface of the sliding shells (51) is slidably connected to the inner cavity of the guide slide cylinder (12), the end of the spring pressure rod (55) away from the sliding shell (51) is slidably connected to the inner wall of the main valve cylinder (2), and the side of the waterproof cushion (53) close to the spring pressure rod (55) is pressed against the inner wall of the guide slide cylinder (12).

7. The straight-through pressure relief valve according to claim 1, characterized in that: The drainage device (4) comprises a rotating bottom cylinder (41), a drainage groove (42) is symmetrically provided in the middle of the inner cavity of the rotating bottom cylinder (41), a switching rotating cylinder (43) is rotatably connected to the bottom of the outer surface of the rotating bottom cylinder (41), a docking groove (44) is symmetrically provided in the inner cavity of the switching rotating cylinder (43), and pressure-bearing air bags (45) are symmetrically provided on both sides of the inner wall of the switching rotating cylinder (43), and the inner cavity of the pressure-bearing air bag (45) is fixedly connected to a pressure-sensitive plate (46) through a thrust rod.

8. The straight-through pressure relief valve according to claim 7, characterized in that: There are two pressurized air bags (45), the outer surface of which is slidably connected to the inner wall of the switching cylinder (43), the outer surface of the pressure-sensitive plate (46) is fixedly connected to one side of the outer surface of the switching cylinder (43), and the upper surface of the rotating bottom cylinder (41) is fixedly connected to the bottom end of the main valve cylinder (2).

9. The straight-through pressure relief valve according to claim 8, characterized in that: The number of the drainage grooves (42) is two, the number of the docking grooves (44) is two, and the docking grooves (44) extend to the upper and lower sides of the outer surface of the switching cylinder (43), and the axis of the top of the rotating bottom cylinder (41) extends to the bottom of the inner cavity of the main valve cylinder (2).

Images