Pressure reducing valve

Abstract

The invention belongs to the technical field of valves, and discloses a pressure reducing valve. The pressure reducing valve comprises a valve body, a valve element frame and a valve clack, the valve element frame is arranged in the valve body, the valve clack is arranged in the valve element frame in a sliding mode, a water passing hole is formed in the side face of the valve element frame, and a water outlet hole communicated with the water passing hole is formed in the bottom of the valve element frame. The connecting section penetrates through the water outlet hole, an annular gap allowing fluid to pass through is formed between the connecting section and the hole wall of the water outlet hole, the hole diameter of the water outlet hole is defined as E, the diameter of the connecting section is defined as D, and D / E is larger than or equal to 0.75 and smaller than or equal to 0.85. By increasing the diameter D of the connecting section, D / E is kept within the specific range of 0.75-0.85, the flow can be effectively improved on the contrary, and the pressure drop change rate of a flow pressure characteristic curve is more stable.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, and in particular to a pressure reducing valve. Background Art

[0002] The operation of the piston pressure reducing valve is controlled by the pressure behind the valve. When the pressure behind the valve increases, the valve opening of the pressure reducing valve decreases; when the pressure behind the valve decreases, the valve opening of the pressure reducing valve increases to meet the control requirements.

[0003] The existing pressure reducing valve usually includes a valve body, a valve core frame fixed in the valve body, and a valve disc arranged in the valve core frame and moving up and down relative to the valve core frame to change the medium channel and the medium flow rate. A water through hole is provided on the side of the valve core frame, and a water outlet hole connected to the water through hole is provided at the bottom of the valve core frame. The valve disc includes a connecting section, which passes through the water outlet hole and forms an annular gap with the hole wall of the water outlet hole for fluid to pass through. After the water flows into the water through hole on the peripheral side of the valve core frame, it flows out from the gap between the connecting section and the hole wall of the water outlet hole.

[0004] It is generally believed in the industry that the smaller the diameter of the connecting section, that is, the larger the gap between the connecting section and the wall of the water outlet, the greater the flow rate of the pressure reducing valve. However, during the actual test, the inventor found that the smaller the diameter of the connecting section, the greater the flow rate; on the contrary, the inventor found through multiple experiments that within a certain range, increasing the diameter of the connecting section can effectively increase the flow rate, and the pressure drop change rate of the flow-pressure characteristic curve is stable. Summary of the invention

[0005] The object of the present invention is to provide a pressure reducing valve, which increases the diameter of the connecting section so that the diameter of the connecting section and the aperture of the water outlet are maintained within a certain range, the flow rate can be effectively improved, and the pressure drop change rate of the flow-pressure characteristic curve is more stable.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] A pressure reducing valve comprises a valve body, a valve core frame and a valve flap, wherein the valve core frame is arranged in the valve body, the valve flap is slidably arranged in the valve core frame, a water through hole is provided on the side of the valve core frame, a water outlet hole connected to the water through hole is provided on the bottom of the valve core frame, and the valve flap comprises a connecting section, the connecting section passes through the water outlet hole and forms an annular gap with the hole wall of the water outlet hole for fluid to pass through, wherein the aperture of the water outlet hole is defined as E, the diameter of the connecting section is defined as D, and D / E is greater than or equal to 0.75 and less than or equal to 0.85.

[0008] As an optional solution, D / E is greater than or equal to 0.8 and less than or equal to 0.85.

[0009] As an alternative, D / E is 0.8.

[0010] As an optional scheme, the valve flap also includes a first boss and a second boss, the first boss is connected between the second boss and the connecting section, the diameter of the first boss is larger than the diameter of the connecting section and smaller than the diameter of the second boss, the step surface between the first boss and the second boss is the valve rear pressure action surface, and the step surface between the first boss and the connecting section is the valve front pressure action surface.

[0011] As an optional solution, a first step is protruding from the inner side wall of the valve core frame, and the rear valve pressure action surface can abut against the first step.

[0012] As an optional solution, the valve core frame is provided with a plurality of water guide holes extending along its axial direction, the upper ends of the water guide holes penetrate the step surface of the first step, and the lower ends of the water guide holes penetrate the bottom of the valve core frame.

[0013] As an optional solution, a first sealing groove is formed on the outer side wall of the first boss, a first sealing ring is disposed in the first sealing groove, and an outer ring of the first sealing ring abuts against the valve core frame;

[0014] A second sealing groove is formed on the outer side wall of the second boss, a second sealing ring is disposed in the second sealing groove, and an outer ring of the second sealing ring abuts against the inner wall of the valve core frame.

[0015] As an optional solution, the valve flap also includes a retaining ring and a connecting section, the retaining ring is connected to the bottom end of the connecting section, the connecting section is connected to the bottom end of the retaining ring, the diameter of the connecting section is smaller than the diameter of the retaining ring, a sealing seat is provided at the bottom of the connecting section, a sealing gasket is provided on the outer sleeve of the connecting section, and the sealing gasket is pressed between the retaining ring and the sealing seat.

[0016] As an optional solution, the bottom end of the valve core frame is also provided with a step hole and an open hole connected to the water outlet, the step hole ring is arranged on the outer peripheral side of the bottom of the water outlet, the open hole ring is arranged on the outer peripheral side of the bottom of the step hole, and the sealing gasket can be against the step surface of the bottom of the step hole. According to the pressure reducing valve according to the claim, the center of the valve disc is provided with a through hole that penetrates axially, a screw is connected to the inner thread of the through hole, the screw extends out of the bottom of the connecting section and is threadedly connected to the sealing seat

[0017] Beneficial effects of the present invention:

[0018] The present invention provides a pressure reducing valve, including a valve body, a valve core frame and a valve flap, wherein the valve core frame is arranged in the valve body, the valve flap is slidably arranged in the valve core frame, a water hole is provided on the side of the valve core frame, a water outlet hole connected to the water hole is provided at the bottom of the valve core frame, and the valve flap includes a connecting section, the water outlet hole is penetrated by the connecting section and an annular gap is formed between the connecting section and the hole wall of the water outlet hole for fluid to pass through, and the water flows into the water hole on the side of the valve core frame and then flows out from the gap between the connecting section and the hole wall of the water outlet hole. Among them, the aperture of the water outlet hole is E, and the diameter of the connecting section is D. By increasing the diameter D of the connecting section, D / E is kept within the specific range of 0.75-0.85, the flow rate can be effectively improved, and the pressure drop change rate of the flow pressure characteristic curve is more stable. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a cross-sectional view of the pressure reducing valve provided by the present invention with part of the structure hidden;

[0020] Figure 2 It is a cross-sectional view of the valve flap and the valve core frame provided by the present invention;

[0021] Figure 3 is a cross-sectional view of the valve flap provided by the present invention;

[0022] Figure 4 is a cross-sectional view of the valve core frame provided by the present invention;

[0023] Figure 5 It is a structural schematic diagram of the valve core frame provided by the present invention;

[0024] Figure 6 It is a structural schematic diagram of the pressure reducing valve provided by the present invention;

[0025] Figure 7 It is a comparison chart of the outlet pressure and flow rate test of the pressure reducing valve provided by the present invention.

[0026] In the figure:

[0027] 1. Valve body; 11. Valve cavity; 12. Water inlet channel; 13. Water outlet channel; 14. Second step;

[0028] 2. Valve core frame; 201. Connecting rib; 21. Water hole; 22. Water outlet hole; 23. Step hole; 24. Open; 25. First step; 26. Water guide hole; 27. Boss; 28. Third sealing groove; 29. ​​Third sealing ring;

[0029] 3. Valve disc; 31. Connecting section; 32. First boss; 321. First sealing groove; 322. First sealing ring; 323. Pressure acting surface before valve; 33. Retaining ring; 34. Connecting section; 35. Through hole; 36. Second boss; 361. Second sealing groove; 362. Second sealing ring; 363. Pressure acting surface after valve; 37. Groove;

[0030] 4. Sealing assembly; 41. Sealing pad; 42. Sealing seat;

[0031] 5. Screws; 6. Gasket; 7. Valve cover; 8. Main spring; 9. Pressure regulating nut. DETAILED DESCRIPTION

[0032] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right", etc., directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] like Figure 1As shown, a pressure reducing valve provided in this embodiment includes a valve body 1, a valve core frame 2 and a valve disc 3. An inlet channel 12, an outlet channel 13 and a valve cavity 11 are provided in the valve body 1. The inlet channel 12 and the outlet channel 13 are respectively used to connect to external pipelines. The valve cavity 11 is connected to the inlet channel 12 and the outlet channel 13 respectively. The valve core frame 2 is a cylindrical multi-boss sleeve structure and is arranged in the valve cavity 11 of the valve body 1. The valve disc 3 is slidably arranged in the valve core frame 2. A plurality of rectangular water holes 21 (as shown in 5) are provided on the side of the valve core frame 2 so that the upstream medium can pass through. A water outlet hole 22 connected to the water hole 21 is provided at the bottom of the valve core frame 2, wherein the water outlet hole 22 is the part with the smallest aperture at the bottom of the valve core frame 2. The valve disc 3 includes a connecting section 31. The connecting section 31 passes through the water outlet hole 22 and forms an annular gap with the hole wall of the water outlet hole 22 for fluid to pass through.

[0037] In actual use, the upstream medium flows in from the water inlet channel 12, then enters the valve core frame 2 through the water through hole 21 on the side of the valve core frame 2, then flows out from the gap between the connecting section 31 and the wall of the water outlet hole 22, and finally flows to the downstream through the water outlet channel 13.

[0038] Among them, Figure 2 As shown, the aperture of the water outlet 22 is defined as E, the diameter of the connecting section 31 is defined as D, and D / E is greater than or equal to 0.75 and less than or equal to 0.85. For example, D / E can be 0.75, 0.76, 0.77, 0.78, 0.79, 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, etc. It is generally believed in the industry that the smaller the diameter D of the connecting section 31, that is, the larger the gap between the connecting section 31 and the hole wall of the water outlet 22, the greater the flow rate of the pressure reducing valve. However, in the actual test process, the inventor found that the smaller the diameter of the connecting section 31, the greater the flow rate; on the contrary, the inventor found through multiple experiments that by increasing the diameter D of the connecting section 31 and keeping D / E within the specific range of 0.75-0.85, the flow rate can be effectively improved, and the pressure drop change rate of the flow pressure characteristic curve is more stable.

[0039] To this end, the inventor conducted a comparative test on the relationship between the aperture E of the water outlet 22 and the diameter D of the connecting section 31, that is, several pressure reducing valves in the range of 0.75≤D / E≤0.85 and several pressure reducing valves with D / E<0.75 were installed on the pressure test bench, a hydraulic pressure of 0.8MPa was applied at the inlet, and the pressure regulating nut 9 of the pressure reducing valve was slowly adjusted to keep the outlet pressure at 0.3MPa, and then the inlet pressure was kept unchanged, and the upstream control valve was slowly opened to allow the medium to flow through the pressure reducing valve. When the flow rate changed from 0 to 1.8m 3 / h, take ten flow point values ​​and record the outlet pressure values ​​corresponding to the ten flow point values, as shown in Table 1. Fit each set of data into the outlet pressure and flow curve, and get the following Figure 7 The pressure reducing valve outlet pressure and flow test comparison chart is shown.

[0040] Table 1

[0041]

[0042]

[0043]

[0044] Depend on Figure 7 It can be seen that compared with the pressure reducing valve with D / E < 0.75, the pressure reducing valve with D / E in the range of 0.75-0.85 has a larger flow rate under the same outlet pressure, and the pressure drop change rate of the flow pressure characteristic curve is relatively stable. Therefore, it is verified that the smaller the diameter of the connecting section 31 is, the greater the flow rate is. Instead, by increasing the diameter D of the connecting section 31 and keeping the D / E in the specific range of 0.75-0.85, the flow rate can be effectively increased, and the pressure drop change rate of the flow pressure characteristic curve is stable.

[0045] Preferably, by Figure 7 It can be seen that D / E is greater than or equal to 0.8 and less than or equal to 0.85. In this range, the flow rate is relatively large when the outlet pressure is the same.

[0046] More preferably, if Figure 7 It can be seen that when D / E is 0.8, the flow rate of the pressure reducing valve is the largest compared with other comparative examples.

[0047] Furthermore, combined with Figure 2 and Figure 3 The valve flap 3 is a cylindrical multi-boss structure. Specifically, the valve flap 3 also includes a first boss 32 and a second boss 36. The first boss 32 is connected between the connecting section 31 and the second boss 36. The diameter of the first boss 32 is larger than the diameter of the connecting section 31 and smaller than the diameter of the second boss 36. The step surface between the first boss 32 and the second boss 36 is the valve rear pressure action surface 363, and the step surface between the first boss 32 and the connecting section 31 is the valve front pressure action surface 323. The first boss 32 is arranged in the valve core frame 2, and the first boss 32 cooperates with the valve core frame 2 to play a sliding guide role.

[0048] Furthermore, if Figures 2 to 4As shown, the inner side wall of the valve core frame 2 is convexly provided with a first step 25, and the valve rear pressure action surface 363 can abut against the first step 25. The first step 25 can limit the movement of the valve flap 3. When the valve flap 3 moves downward to the maximum opening, the valve rear pressure action surface 363 abuts against the first step 25, and the valve flap 3 reaches the limit position of movement.

[0049] like Figure 2 and Figure 5 As shown, the valve core frame 2 is provided with a plurality of water guide holes 26 extending along its axial direction, the upper end of the water guide hole 26 penetrates the step surface of the first step 25, and the lower end of the water guide hole 26 penetrates the bottom of the valve core frame 2. When the upstream medium enters the valve core frame 2 through the water through hole 21 on the peripheral side of the valve core frame 2, the medium force acts upward on the pressure acting surface 323 in front of the valve; then, the medium flows out from the gap between the connecting section 31 and the hole wall of the water outlet hole 22, and finally flows to the downstream through the water outlet channel 13. At this time, the medium enters the water guide hole 26 from the bottom, and the medium force acts upward on the pressure acting surface 363 behind the valve. In this embodiment, there are four water guide holes 26, four water through holes 21, and a connecting rib 201 is provided between two adjacent water through holes 21, and each connecting rib 201 is penetrated by a water guide hole 26.

[0050] like Figure 2 and Figure 3 As shown, a first sealing groove 321 is formed on the outer wall of the first boss 32 , a first sealing ring 322 is disposed in the first sealing groove 321 , and an outer ring of the first sealing ring 322 abuts against the valve core frame 2 , thereby improving the sealing performance between the valve flap 3 and the valve core frame 2 .

[0051] like Figure 2 and Figure 3 As shown, a second sealing groove 361 is opened on the outer wall of the second boss 36, and a second sealing ring 362 is arranged in the second sealing groove 361, and the outer ring of the second sealing ring 362 is against the inner wall of the valve core frame 2, thereby further improving the sealing performance between the valve disc 3 and the valve core frame 2.

[0052] Furthermore, if Figure 2 and Figure 3As shown, the valve flap 3 also includes a retaining ring 33 and a connecting section 34. The retaining ring 33 is connected to the bottom end of the connecting section 31, and the connecting section 34 is connected to the bottom end of the retaining ring 33. The diameter of the connecting section 31 is smaller than the diameter of the retaining ring 33, and larger than the diameter of the connecting section 34. The bottom of the connecting section 34 is provided with a sealing component 4 capable of sealing and closing the water outlet 22. The sealing component 4 includes a sealing seat 42 and a sealing gasket 41. The sealing seat 42 is provided at the bottom of the connecting section 34, and the sealing gasket 41 is sleeved outside the connecting section 34, and the sealing gasket 41 is pressed between the retaining ring 33 and the sealing seat 42. The sealing seat 42 is used to support the sealing gasket 41, and the retaining ring 33 is pressed on the sealing gasket 41 to prevent it from tilting, so that the sealing gasket 41 plays a good sealing role.

[0053] Furthermore, if Figure 2 and Figure 4 As shown, the bottom end of the valve core frame 2 is also provided with a step hole 23 and an opening 24 connected to the water outlet hole 22. The step hole 23 is arranged around the bottom outer peripheral side of the water outlet hole 22, and the opening 24 is arranged around the bottom outer peripheral side of the step hole 23. The sealing gasket 41 can abut against the step surface at the bottom of the step hole 23. Specifically, the aperture of the opening 24 is larger than the aperture of the step hole 23, and the aperture of the step hole 23 is larger than the aperture of the water outlet hole 22. The three are connected in sequence to form a three-level step structure. When the pressure reducing valve is closed, the valve disc 3 drives the sealing assembly 4 to move upward, and the sealing gasket 41 abuts against the step surface at the bottom of the step hole 23 to form a sealing throttling effect, thereby improving the sealing performance. The setting of the opening 24 is to avoid the sealing seat 42 so that the sealing gasket 41 can smoothly enter the step hole 23.

[0054] Furthermore, if Figure 2 and Figure 3 As shown, a through hole 35 is provided in the center of the valve flap 3, which penetrates in the axial direction. A screw 5 is threadedly connected to the through hole 35. The screw 5 extends out of the bottom of the connecting section 34 and is threadedly connected to the sealing seat 42. In this way, the valve flap 3 can be configured as a plastic part, which reduces the cost, reduces scaling and wear, and prolongs the service life. The screw 5 is a metal part, which ensures the connection strength between the valve flap 3 and the sealing seat 42.

[0055] like Figure 2 As shown, a groove 37 is provided at the top center of the valve disc 3, and a gasket 6 is provided at the bottom of the groove 37. The head of the screw 5 is pressed against the gasket 6 to prevent the screw 5 from crushing the valve disc 3. The head of the screw 5 is provided with a hexagonal hole for tightening.

[0056] like Figure 1 and Figure 4As shown, a convex shoulder 27 is convexly provided on the outer peripheral side of the valve core frame 2, and a second step 14 is convexly provided on the inner side wall of the valve body 1. The outer wall of the convex shoulder 27 is threadedly connected to the inner wall of the valve body 1, and the bottom surface of the convex shoulder 27 can abut against the second step 14. This arrangement allows the valve core frame 2 to be firmly connected to the valve body 1 and is easy to disassemble and assemble. The second step 14 can locate the installation position of the valve core frame 2. When the bottom surface of the convex shoulder 27 abuts against the second step 14, it indicates that the valve core frame 2 is installed in place.

[0057] Furthermore, a third sealing groove 28 is opened on the outer wall of the valve core frame 2, and a third sealing ring 29 is placed in the third sealing groove 28, and the outer ring of the third sealing ring 29 is against the inner wall of the valve body 1, thereby improving the sealing performance between the valve core frame 2 and the valve body 1.

[0058] Combination Figure 1 and Figure 6 The pressure reducing valve provided in this embodiment further comprises a valve cover 7, a main spring 8 and a pressure regulating nut 9. The valve cover 7 is threadedly connected to the upper end of the valve body 1 to form a closed valve cavity 11. The pressure regulating nut 9 is threadedly connected to the top of the valve cover 7. One end of the main spring 8 abuts against the pressure regulating nut 9, and the other end extends into the groove 37 at the top of the valve disc 3 and abuts against the gasket 6. The elastic force of the main spring 8 acts downward on the valve disc 3. By screwing the pressure regulating nut 9, the height of the main spring 8 can be changed, thereby adjusting the outlet pressure.

[0059] The working principle of the pressure reducing valve provided in this embodiment is as follows:

[0060] When the upstream medium flows in from the water inlet channel 12, it enters the valve core frame 2 through the water hole 21 on the side of the valve core frame 2. At this time, the medium acts on the valve front pressure surface 323 to generate an upward force; then, the medium flows out from the gap between the connecting section 31 and the wall of the water outlet hole 22, and finally flows to the downstream through the water outlet channel 13. At this time, the medium enters the water guide hole 26 from the bottom, and the medium acts on the valve rear pressure surface 363 to generate an upward force. When the outlet pressure increases and reaches the set value, the pressure of the medium on the valve front pressure surface 323 remains unchanged, and the pressure on the valve rear pressure surface 363 increases. At this time, the sum of the pressure of the medium on the valve front pressure surface 323 and the pressure on the valve rear pressure surface 363 is greater than the downward force of the main spring 8, thereby overcoming the downward force of the main spring 8 to make the valve disc 3 move upward, reduce the valve opening, increase the flow rate, increase the pressure drop, and reduce the downstream pressure of the valve. If the outlet pressure drops, the pressure of the medium on the pressure acting surface 323 in front of the valve remains unchanged, and the pressure acting on the pressure acting surface 363 behind the valve decreases. At this time, the sum of the pressure of the medium on the pressure acting surface 323 in front of the valve and the pressure acting on the pressure acting surface 363 behind the valve is less than the downward force of the main spring 8, causing the valve disc 3 to move downward, the valve opening to increase, the flow rate to decrease, the pressure drop to decrease, and the pressure downstream of the valve to increase, thereby keeping the outlet pressure of the valve body 1 constant.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. Pressure reducing valve, characterized in that: The invention comprises a valve body (1), a valve core frame (2) and a valve flap (3), wherein the valve core frame (2) is arranged in the valve body (1), the valve flap (3) is slidably arranged in the valve core frame (2), a water through hole (21) is provided on the side of the valve core frame (2), a water outlet hole (22) connected to the water through hole (21) is provided on the bottom of the valve core frame (2), and the valve flap (3) comprises a connecting section (31), the connecting section (31) passes through the water outlet hole (22) and forms an annular gap with the hole wall of the water outlet hole (22) for fluid to pass through, wherein the aperture of the water outlet hole (22) is defined as E, the diameter of the connecting section (31) is defined as D, and D / E is greater than or equal to 0.75 and less than or equal to 0.

85.

2. The pressure reducing valve according to claim 1, characterized in that: D / E is greater than or equal to 0.8 and less than or equal to 0.

85.

3. The pressure reducing valve according to claim 2, characterized in that: D / E is 0.

8.

4. The pressure reducing valve according to claim 1, characterized in that: The valve flap (3) further comprises a first boss (32) and a second boss (36); the first boss (32) is connected between the second boss (36) and the connecting section (31); the diameter of the first boss (32) is larger than the diameter of the connecting section (31) and smaller than the diameter of the second boss (36); the step surface between the first boss (32) and the second boss (36) is a valve rear pressure action surface (363); and the step surface between the first boss (32) and the connecting section (31) is a valve front pressure action surface (323).

5. The pressure reducing valve according to claim 4, characterized in that: The inner side wall of the valve core frame (2) is protrudingly provided with a first step (25), and the valve rear pressure action surface (361) can abut against the first step (25).

6. The pressure reducing valve according to claim 5, characterized in that: The valve core frame (2) is provided with a plurality of water guide holes (26) extending along its axial direction, the upper ends of the water guide holes (26) penetrate the step surface of the first step (25), and the lower ends of the water guide holes (26) penetrate the bottom of the valve core frame (2).

7. The pressure reducing valve according to claim 4, characterized in that: A first sealing groove (321) is formed on the outer side wall of the first boss (32), a first sealing ring (322) is disposed in the first sealing groove (321), and the outer ring of the first sealing ring (322) abuts against the valve core frame (2); A second sealing groove (361) is provided on the outer side wall of the second boss (36), a second sealing ring (362) is accommodated in the second sealing groove (361), and the outer ring of the second sealing ring (362) abuts against the inner wall of the valve core frame (2).

8. The pressure reducing valve according to claim 1, characterized in that: The valve flap (3) further comprises a retaining ring (33) and a connecting section (34); the retaining ring (33) is connected to the bottom end of the connecting section (31); the connecting section (34) is connected to the bottom end of the retaining ring (33); the diameter of the connecting section (31) is smaller than the diameter of the retaining ring (33); a sealing seat (42) is arranged at the bottom of the connecting section (34); a sealing gasket (41) is arranged on the outer sleeve of the connecting section (34); the sealing gasket (41) is pressed tightly between the retaining ring (33) and the sealing seat (42).

9. The pressure reducing valve according to claim 8, characterized in that: The bottom end of the valve core frame (2) is also provided with a step hole (23) and an opening (24) which are connected to the water outlet hole (22); the step hole (23) is arranged around the bottom outer peripheral side of the water outlet hole (22); the opening (24) is arranged around the bottom outer peripheral side of the step hole (23); and the sealing gasket (41) can be abutted against the step surface at the bottom of the step hole (23).

10. The pressure reducing valve according to claim 8, characterized in that: A through hole (35) extending axially through the center of the valve flap (3) is provided. A screw (5) is threadedly connected to the through hole (35). The screw (5) extends out of the bottom of the connecting section (34) and is threadedly connected to the sealing seat (42).

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