Pilot piston type pressure reducing valve

Abstract

The utility model discloses a pilot piston type pressure reducing valve, which relates to the technical field of valves, and comprises a main valve body, a main valve core, a pilot valve seat, a pilot valve core, a linkage piston and a filter element, a piston cavity, an inlet cavity and an outlet cavity are arranged in the main valve body, the filter element comprises a sealing stud and a filter screen, the filter screen is arranged between a first channel and the pilot valve core, and the linkage piston is arranged in the piston cavity. The sealing stud and the pilot valve seat are connected to the outer side of the filter screen in a screwed mode, a stop valve used for cutting off the first channel is arranged on the outer side of the first channel and provided with an operation handle, and an interlocking mechanism is arranged between the operation handle and the sealing stud. When the filter screen is replaced, media can be temporarily cut off, impurities are prevented from entering the pilot valve and the piston cavity, and the precision of the pilot part of the pressure reducing valve is effectively guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of valves, and particularly relates to a pilot piston type pressure reducing valve. Background Art

[0002] The pilot piston type pressure reducing valve is composed of a main valve and a pilot valve. It mainly drives a piston through the opening and closing of the pilot valve to adjust the flow area of the throttling part of the main valve, so as to achieve the functions of pressure reduction and pressure stabilization. In some application scenarios, the medium often contains impurities such as solid particles. The impurities are likely to accumulate at the piston and jam the piston, resulting in the failure of the pressure reducing valve. Therefore, the existing pilot piston type pressure reducing valve usually has a through hole opened on the side of the pilot valve. A filter screen is installed in the through hole to filter impurities, and a plug is installed outside the filter screen to prevent impurities from entering the piston cavity and jamming the piston.

[0003] With continuous use, impurities will continuously accumulate on the surface of the filter screen. After long-term use, the liquid throughput at the filter screen will decrease. At this time, it is necessary to remove the plug and take out the filter screen for cleaning or replacement. After removing the filter screen, the medium will directly enter the pilot valve without passing through the filter, causing internal impurity accumulation and affecting the precision of the pilot part. Summary of the Invention

[0004] Aiming at the deficiencies of the prior art, the utility model provides a pilot piston type pressure reducing valve.

[0005] The technical solution provided by the utility model is as follows:

[0006] A pilot piston type pressure reducing valve includes a main valve body, a main valve core, a pilot valve seat, a pilot valve core, a linkage piston, and a filter element. The pilot valve seat and the pilot valve core are arranged on the main valve body. A piston cavity, an inlet cavity, and an outlet cavity are arranged in the main valve body. The linkage piston is slidably arranged in the piston cavity. The pilot valve seat is communicated with the inlet cavity, the piston cavity, and the outlet cavity respectively through a first channel, a second channel, and a third channel. The main valve core is arranged in the main valve body. A main valve seat for cooperating with the main valve core for sealing is arranged between the inlet cavity and the outlet cavity. The upper end of the main valve core includes a main valve rod, and the main valve rod extends upward into the piston cavity and is connected with the linkage piston. The filter element includes a sealing stud and a filter screen. The filter screen is arranged between the first channel and the pilot valve core. The sealing stud is screwed with the pilot valve seat outside the filter screen. A stop valve for cutting off the first channel is arranged outside the first channel. The stop valve is provided with an operating handle. An interlocking mechanism is arranged between the operating handle and the sealing stud. The interlocking mechanism makes the sealing stud unable to be opened when the stop valve is in the open state, and can open the sealing stud to replace the filter screen when the stop valve is in the closed state.

[0007] The interlock mechanism includes a sleeve disc, which is fixed outside the sealing stud. There are several pin holes on the side of the sleeve disc, and a pin is provided on the operating handle. The pin rotates coaxially with the operating handle. The pin has a first position that is limited in the pin hole to prevent the sealing stud from being opened and a second position that disengages from the pin hole to enable the sealing stud to be opened.

[0008] A rubber pad is provided in the pin hole, and the pin is in interference fit with the rubber pad.

[0009] An adjusting member is provided above the pilot valve seat. The adjusting member includes an upper spring seat, an adjusting spring, and an adjusting screw. One end of the adjusting spring presses against the pilot valve seat, and the other end presses against the upper spring seat. The lower end of the adjusting screw presses against the upper spring seat.

[0010] A protective cover is provided on the adjusting screw.

[0011] A diaphragm is provided at the lower end of the pilot valve seat. The lower end of the pilot valve seat abuts against the upper end of the diaphragm, the upper end of the pilot valve core abuts against the lower end of the diaphragm, and a pilot valve core spring is provided at the lower end of the pilot valve core.

[0012] A piston cylinder sleeve is provided in the piston cavity, and a piston seal ring is provided between the piston cylinder sleeve and the linkage piston.

[0013] A guide sleeve is provided in the piston cavity, and the guide sleeve is sleeved outside the main valve core.

[0014] A bottom cover is provided at the lower end of the main valve body, and a main valve core spring is provided between the main valve core and the bottom cover.

[0015] The beneficial effects of the present utility model: By providing a stop valve for cutting off the first channel outside the first channel, the stop valve is provided with an operating handle, and an interlock mechanism is provided between the operating handle and the sealing stud. When the stop valve is in the open state, the interlock mechanism prevents the sealing stud from being opened. After the stop valve is closed, the sealing stud can be opened to replace the filter screen. The stop valve temporarily cuts off the medium to prevent impurities from entering the pilot valve and the piston cavity, ensuring the precision of the pilot part of the pressure reducing valve. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of an embodiment of the present utility model;

[0017] Figure 2 is Figure 1 a partial enlarged view of Detailed Embodiments

[0018] The embodiments of the present utility model will be further described below in conjunction with the drawings.

[0019] As Figure 1-2As shown in the figure, a pilot piston type pressure reducing valve includes a main valve body 1, a main valve core 4, a pilot valve seat 16, a pilot valve core 15, a linkage piston 6, and a filter element. The pilot valve seat 16 and the pilot valve core 15 are arranged on the main valve body 1. A piston chamber 13, an inlet chamber 11, and an outlet chamber 12 are provided in the main valve body 1. The linkage piston 6 is slidably arranged in the piston chamber 13. The pilot valve seat 16 is communicated with the inlet chamber 11, the piston chamber 13, and the outlet chamber 12 respectively through a first channel 21, a second channel 22, and a third channel 23. The main valve core 4 is arranged in the main valve body 1. A bottom cover 2 is provided at the lower end of the main valve body 1. A main valve core spring 3 is arranged between the main valve core 4 and the bottom cover 2. A main valve seat for sealing cooperation with the main valve core 4 is arranged between the inlet chamber 11 and the outlet chamber 12. The upper end of the main valve core 4 includes a main valve stem, and the main valve stem extends upward into the piston chamber 13 and is connected to the linkage piston 6. The filter element includes a sealing stud 10 and a filter net 9. The filter net 9 is arranged between the first channel 21 and the pilot valve core 15. The sealing stud 10 is screwed with the pilot valve seat outside the filter net 9. A stop valve 8 for cutting off the first channel is arranged outside the first channel 21. The stop valve 8 is arranged on the outer surface of the main valve body 1. The stop valve 8 is provided with an operating handle 31. A sleeve plate 33 is fixed outside the sealing stud 10. A plurality of pin holes 34 are arranged on the side of the sleeve plate 33. A pin 32 is arranged on the operating handle 31. The pin 32 rotates coaxially with the operating handle 31. In the normal working state, the stop valve 8 is in an open state, and the pin 32 is limited in the pin hole 34. At this time, the sealing stud 10 cannot be rotated. When the filter net 9 needs to be replaced, the operating handle 31 is rotated to close the stop valve, so that the pin 32 is disengaged from the pin hole 34, and then the sealing stud 10 can be rotated and the filter net 9 can be taken out for cleaning or replacement. The stop valve 8 temporarily cuts off the medium to prevent impurities from entering the pilot valve and the piston chamber, ensuring the precision of the pilot part of the pressure reducing valve. Further, a rubber pad 35 is arranged in the pin hole 34, and the pin 32 is in interference fit with the rubber pad 35 to prevent the pin 32 from being disengaged from the pin hole 34 due to vibration or the like, affecting the interlocking effect.

[0020] In this embodiment, an adjusting member is arranged above the pilot valve seat 16. The adjusting member includes an upper spring seat 19, an adjusting spring 18, and an adjusting screw 20. One end of the adjusting spring 18 presses against the pilot valve seat 16, and the other end presses against the upper spring seat 19. The lower end of the adjusting screw 20 presses against the upper spring seat 19. A diaphragm 17 is arranged at the lower end of the pilot valve seat 16. The lower end of the pilot valve seat 16 abuts against the upper end of the diaphragm 17. The upper end of the pilot valve core 15 abuts against the lower end of the diaphragm 17. A pilot valve core spring 14 is arranged at the lower end of the pilot valve core 15. By adjusting the adjusting screw 20, the opening pressure of the pilot valve can be conveniently adjusted. Further, a protective cover 24 is arranged on the adjusting screw 20 to effectively protect the adjusting screw 20 and extend its service life.

[0021] In this embodiment, a piston cylinder sleeve 7 is arranged in the piston chamber 13. A piston sealing ring 6 is arranged between the piston cylinder sleeve 7 and the linkage piston 5 to ensure that there is no leakage when the linkage piston 5 moves up and down. The piston cylinder sleeve 7 can reduce the wear of the linkage piston 5 and extend its service life.

[0022] In this embodiment, a guide sleeve 29 is provided in the piston chamber 13. The guide sleeve 29 is sleeved outside the main valve core 4, so that the main valve core 4 will not deviate when moving up and down, ensuring the reliability of the valve seal.

[0023] The embodiments should not be construed as limiting the present invention, and any non-creative improvements made based on the spirit of the present invention should be regarded as within the protection scope of the present invention.

Claims

1. A pilot piston pressure reducing valve, comprising a main valve body, a main valve core, a pilot valve seat, a pilot valve core, a linkage piston, and a filter element, wherein the pilot valve seat and the pilot valve core are arranged on the main valve body, a piston cavity, an inlet cavity, and an outlet cavity are arranged in the main valve body, the linkage piston is slidably arranged in the piston cavity, the pilot valve seat is connected with the inlet cavity, the piston cavity, and the outlet cavity through a first channel, a second channel, and a third channel respectively, the main valve core is arranged in the main valve body, a main valve seat which cooperates with the main valve core to seal is arranged between the inlet cavity and the outlet cavity, the upper end of the main valve core comprises a main valve stem, the main valve stem extends upward into the piston cavity and is connected to the linkage piston, the filter element comprises a sealing stud and a filter screen, the filter screen is arranged between the first channel and the pilot valve core, the sealing stud and the pilot valve seat are screwed to the outside of the filter screen, and the characteristics are: A stop valve for cutting off the first channel is provided on the outside of the first channel, the stop valve is provided with an operating handle, an interlocking mechanism is provided between the operating handle and the sealing stud, the interlocking mechanism prevents the sealing stud from being opened when the stop valve is in an open state, and the sealing stud can be opened to replace the filter screen when the stop valve is in a closed state.

2. A pilot piston type pressure reducing valve according to claim 1, characterized in that: The interlocking mechanism includes a sleeve disk, which is fixed to the outside of the sealing stud. A plurality of pin holes are provided on the side of the sleeve disk. A pin is provided on the operating handle. The pin rotates coaxially with the operating handle. The pin has a first position limited to the pin hole so that the sealing stud cannot be opened and a second position detached from the pin hole so that the sealing stud can be opened.

3. A pilot piston type pressure reducing valve according to claim 2, characterized in that: A rubber pad is arranged in the pin hole, and the pin column and the rubber pad are interference fit.

4. A pilot piston type pressure reducing valve according to claim 1, characterized in that: An adjusting member is provided above the pilot valve seat, and the adjusting member comprises an upper spring seat, an adjusting spring, and an adjusting screw. One end of the adjusting spring presses against the pilot valve seat, and the other end presses against the upper spring seat. The lower end of the adjusting screw presses against the upper spring seat.

5. A pilot piston type pressure reducing valve according to claim 4, characterized in that: A protective cover is arranged on the adjusting screw.

6. The pilot piston type pressure reducing valve according to claim 1, characterized in that: A diaphragm is arranged at the lower end of the pilot valve seat, the lower end of the pilot valve seat abuts against the upper end of the diaphragm, the upper end of the pilot valve core abuts against the lower end of the diaphragm, and a pilot valve core spring is arranged at the lower end of the pilot valve core.

7. The pilot piston type pressure reducing valve according to claim 1, characterized in that: A piston sleeve is arranged in the piston cavity, and a piston sealing ring is arranged between the piston sleeve and the linkage piston.

8. The pilot piston type pressure reducing valve according to claim 1, characterized in that: A guide sleeve is arranged in the piston cavity, and the guide sleeve is arranged on the outer side of the main valve core.

9. The pilot piston type pressure reducing valve according to claim 1, characterized in that: A bottom cover is arranged at the lower end of the main valve body, and a main valve core spring is arranged between the main valve core and the bottom cover.

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