[0028] Such as figure 1 , figure 2 As shown, the arrow in the figure shows the gas flow direction. The high-pressure pressure reducing valve provided by the present invention includes upper and lower valve bodies 7, 14 connected by threads. The upper valve body 7 slides and seals the piston through the piston mounting hole. 9. The top of the piston 9 is provided with a spring pressure regulating device. The spring pressure regulating device includes a pressure regulating knob 1 screwed on the top of the upper valve body 7, a pressure regulating shaft 3 fixedly connected to the pressure regulating knob 1, and a rotating assembly at the lower end of the pressure regulating shaft 3. The pressure regulating spring seat 5, the piston seat 8 assembled at the top of the piston 9, and the pressure regulating spring 6 mounted between the pressure regulating spring seat 5 and the piston seat 8. A thrust ball bearing 4 is installed between the pressure regulating shaft 3 and the pressure regulating spring seat 5, and the pressure regulating spring 6 is connected between the pressure regulating spring seat 5 and the piston seat 8; the lower end of the piston 9 is embedded with inherent non-metallic overflow Seat 22, the axis of the piston 9 is provided with an overflow flow hole, and the outer diameter of the piston 9 is machined with multiple ring grooves and O-ring sealing devices. The ring grooves enable the piston 9 to have a good centering performance. The compression of the ring is small, which is beneficial to reduce the friction when the piston 9 moves. The outer diameter of the piston 9 matches the piston mounting hole on the upper valve body 7, and the upper spherical surface of the piston 9 matches the tapered hole on the piston seat 8. Face-to-line contact, this structural design can make the piston 9 have a small diameter, light weight, small inertia, low friction, and flexible movement. At the same time, due to the reduction of the piston area, the design of the pressure regulating spring 6 is easy, and the spring stiffness is small, which is conducive to improving the outlet pressure regulation accuracy of the pressure reducing valve, increasing the sensitivity and improving the response speed. At the same time, due to the size of the pressure regulating spring 6 The small structure makes the entire pressure reducing valve small in size, light in weight and compact in structure. The piston seat 8 is pressed on the seat surface of the upper valve body 7 under the action of the pressure regulating spring 6. The upper end of the pressure regulating spring 6 is a pressure regulating spring seat 5, and a thrust is installed between the pressure regulating spring seat 5 and the pressure regulating shaft 3. Ball bearing 3 and thrust ball bearing 3 make pressure adjustment flexible, saving time and effort. The pressure regulating knob 1 and the pressure regulating shaft 3 are firmly connected together, and the pressure regulating shaft 3 and the upper valve seat 2 are driven by a thread to adjust the compression amount of the pressure regulating spring 6.
[0029] The lower valve body 14 is provided with an air inlet, an air outlet, and an air inlet cavity and an air outlet cavity respectively communicating with the inlet and outlet ports. The bottom end of the piston 9 is arranged in the upper air outlet cavity, and the lower valve body 14 is in A valve seat 12 is provided between the lower air inlet cavity and the upper air outlet cavity. The valve seat 12 is provided with a throttle hole which is connected between the air inlet cavity and the air outlet cavity. A valve core 11 is inserted and fitted in the throttle hole. , The valve core 11 includes a frustum structure matched with the lower orifice of the orifice, and an upper spool and a lower spool 21 connected to the top and bottom ends of the frustum. The throttle cone of the frustum is set in the axial direction. In the middle of the air inlet cavity of the air inlet, the throttle cone surface of the frustum and the sharp edge of the orifice under the valve seat 12 form a throttle window, and the top of the spool on the valve core 11 presses against the bottom of the piston 9 And in the outlet cavity. A lower valve cavity is provided below the spool 11 to communicate with the air outlet, and the lower spool 21 is slidably fitted into the spool mounting hole of the lower valve body 14 and inserted directly into the lower valve cavity. The shaft diameter of the lower spool 21 is equal to the aperture D of the orifice of the valve seat 12, the lower spool 21 and the spool mounting hole are a sliding fit with a small fit gap, and the shaft diameter of the lower spool 21 has multiple openings. The ring groove, the ring groove plays a role of sealing and equalizing pressure to reduce the clamping force and friction force when the lower spool 21 moves, so that the spool 11 can move flexibly, and the lower end of the lower spool 21 is reset by the assembly in the lower valve cavity The spring 13 exerts an upward axial force. Since the upper and lower parts of the valve core 11 are in communication with the outlet cavity, this structure makes the axial force of the inlet pressure acting on the valve core 11 zero. The outlet pressure acts on the upper and lower axial forces of the valve core 11 in an upward direction. The effective area of the outlet pressure acting on the valve core 11 is the contact aperture between the upper spherical surface of the valve core 11 and the non-metallic overflow seat 22 embedded in the piston 9 D 0 The sealing area formed due to the overflow aperture D 0 Very small, the upward axial force exerted by the outlet pressure on the valve core 11 is not large. Because the valve core 11 and the lower valve body 14 are in a clearance and sliding fit, the frictional force relative to the return spring 13 is very small and can be ignored. The valve core 11 is subjected to the upward axial force of both the return spring 13 and the outlet air pressure, so that the upper spherical surface of the valve core 11 is pressed and fixed on the hole in the non-metal overflow seat 22 on the piston 9.
[0030] As shown in 2, the lower valve body 14 is also provided with a safety overflow channel 20 between the air outlet and the outside atmosphere, and a safety overflow device is provided in the safety overflow channel. The safety overflow device includes a pressure regulating nut 16 screwed into the safety overflow channel, a ball seat 18 top-mounted on the pressure regulating nut 16 by a safety spring 17, and a corresponding seal on the ball seat 18 and the safety overflow channel. The steel ball 19 at the orifice, the ball seat 18 and the steel ball 19 are arranged on the side of the pressure regulating nut 16 close to the air outlet of the valve body. A lock nut 15 mounted on the pressure regulating nut 16 is screwed into the safety overflow channel on the side of the pressure regulating nut 16 away from the air outlet of the valve body. When the safety overflow device is in use, the pressure regulating nut 16 compresses the safety spring 17, and the compressed safety spring 17 presses the steel ball 19 on the throttling round table of the lower valve body through the ball seat 18 to play a sealing role, and the taper hole communicates with the outlet , The outlet air pressure acts on the steel ball 19, when the outlet air pressure acts on the steel ball 19 when the pressure is greater than the safety pressure set by the safety spring 17, the steel ball 19 is lifted by the air pressure and separated from the cone surface, and the airflow is separated from the steel ball 19 The gap between the surface of the cone and the cone hole overflows, so that the outlet pressure is quickly reduced and restored to the set pressure value. When the pressure regulating nut 16 is adjusted to an appropriate safety pressure, the lock nut 15 is tightened to prevent loosening.
[0031] An adjustment washer 10 is provided between the contact end surfaces of the upper and lower valve bodies 7 and 14. When the valve body is working, the conical surface of the valve core 11 and the edge of the orifice on the lower end of the throttle hole of the valve seat 12 form an initial throttling window with a constant opening. The area of this initial throttling window determines the maximum pressure reducing valve. Flow rate, by replacing the adjusting gasket 10 with different thickness, the initial throttle window area between the valve core 11 and the valve seat 12 can be adjusted to meet different maximum flow requirements.
[0032] When the pressure reducing valve of the embodiment of the present invention is working, the pressure regulating shaft 3 fixedly connected with the pressure regulating knob 1 is rotated, and the pressure regulating spring 6 is compressed through the thrust ball bearing 4 and the pressure regulating spring seat 5. The force of the pressure regulating spring 6 The piston seat 8 is transmitted to the seat surface of the upper valve body 7, and the compression amount of the pressure regulating spring 6 determines the outlet pressure of the pressure reducing valve. When there is no pressure input at the inlet of the pressure reducing valve, the return spring 13 pushes the valve core 11 upwards, and the force is applied to the piston 9 through the valve core 11. The upper spherical surface of the piston 9 contacts the piston seat 8, because the return spring 13 acts on The force on the piston seat 8 is less than the force of the pressure regulating spring 6 on the piston seat 8, and the piston seat 8 will not move upwards. At this time, the cone surface of the valve core 11 and the edge of the lower end surface of the valve seat 12 An initial throttling window with a constant opening is formed. The area of this initial throttling window determines the maximum flow rate of the pressure reducing valve. The size of the initial throttling window can be changed by changing the thickness of the adjustment gasket 10 to meet different maximum flow rates. demand. When there is pressure input at the inlet of the pressure reducing valve, the inlet airflow flows into the outlet through the throttle window, and the pressure built up at the outlet gradually rises. When the outlet pressure approaches the pressure set by the pressure regulating spring 6, the return spring acting on the piston 9 13 When the sum of the upward force and the outlet air pressure acting on the lower end of the piston 9 is greater than the downward force of the pressure regulating spring 6 on the piston 9, the piston 9 moves upward, and the valve core 11 acts on the return spring 13 As the piston 9 moves upward under the force, the area of the throttle window is reduced, and the effect of throttling and decompression is enhanced. When the outlet pressure reaches the set pressure, the forces on the piston 9 up and down are balanced, and the piston 9 and the valve core 11 stop moving. The outlet has a stable pressure output. When the outlet flow suddenly increases and the area of the throttle window does not change, the outlet pressure must decrease. At this time, the outlet pressure acts on the piston 9 to decrease, and the pressure regulating spring 6 presses the piston 9 to move downward, and the piston 9 presses the valve. The core 11 moves downwards, the area of the throttle window increases, and the throttling effect is weakened, so that the outlet pressure rises and returns to the set pressure. The enlarged throttle window area can also meet the demand for increasing the flow. In the same way, when the outlet flow decreases suddenly, the pressure reducing valve can also keep the output pressure stable.
[0033] Under the action of the return spring 13, the upper spherical surface of the valve core 11 is in close contact with the overflow seat 22 embedded in the piston 9. When the outlet pressure suddenly rises, a small part of the gas passes through the overflow seat 22 and the inner part of the piston 9. The hole is discharged to the outside of the pressure reducing valve, so that the outlet pressure drops quickly, which is beneficial to improve the precision and sensitivity of voltage stabilization.
[0034] In addition, since the inlet pressure of the pressure reducing valve exerts zero axial force on the spool 11, the fluctuation of the inlet pressure will not be transmitted to the sensitive element piston 9, so it will not affect the outlet pressure, as long as the inlet pressure is greater than or Slightly higher than the outlet pressure, the pressure reducing valve can work normally. This kind of pressure reducing valve has a wide range of pressure adjustment, and the highest outlet set pressure is slightly lower than the inlet pressure.
