Constant-pressure non-return device of variable frequency pump
By installing a constant pressure check device at the outlet of the variable frequency pump, the problem of water dripping when the pump is shut down is solved, the self-starting time interval of the variable frequency pump is extended, and the variable frequency pump equipment is protected.
Patent Information
- Application Number
- CN202520228368.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-13
- Publication Date
- 2026-02-24
- Estimated Expiration
- 2035-02-13
AI Technical Summary
When the pump is shut down, a slight dripping phenomenon may occur, which leads to a slow drop in water pressure, frequent self-starting, and wasted energy. At the same time, changes in water flow and water pressure can easily cause water hammer effect and damage the pump set.
Design a constant pressure check device, including a constant pressure check pipeline, a pressure tank and a check valve assembly. The pressure tank stabilizes the water pressure in the pipeline, and the check valve assembly prevents backflow and protects the variable frequency pump.
It extends the self-starting time interval of the variable frequency pump, reduces energy waste, prevents water hammer effect from damaging the pump set, and protects the variable frequency pump equipment.
Smart Images
Figure CN223938226U_ABST
Abstract
Description
Technical fields:
[0001] This utility model belongs to the field of variable frequency pump technology, and specifically refers to a constant pressure check device for a variable frequency pump. Background technology:
[0002] As a type of water pump, the variable frequency pump has a constant pressure water supply function, which can automatically adjust the motor frequency according to the actual water use conditions to maintain a stable water supply pressure. However, the following problems still exist in the actual application of variable frequency pumps: First, when the nozzle is turned off and the pump is stopped, because a certain water pressure is maintained in the pipeline, a slight dripping of water may occur at the nozzle, causing the water pressure in the pipeline to drop slowly. The variable frequency pump then automatically restarts to maintain the water pressure, but the interval between automatic restarts is short and relatively frequent, which is very wasteful of energy. Second, when the variable frequency pump starts or stops, the water flow and water pressure in the pipeline will change drastically, which can easily cause backflow of water and cause water hammer effect, which can seriously damage the variable frequency pump and its motor unit. Summary of the Invention:
[0003] The purpose of this invention is to provide a constant pressure check valve for a variable frequency pump. It is installed at the outlet of the variable frequency pump. Even if water drips outward from the nozzle when the pump is turned off, the pressure tank can stabilize the water pressure in the pipeline, thereby effectively extending the self-starting time interval of the variable frequency pump. The check valve assembly is designed in the inner pipeline of the pressure tank, which can effectively protect the variable frequency pump. At the same time, the pressure tank can eliminate the impact caused by backflow due to rapid changes in water flow and water pressure.
[0004] This utility model is implemented as follows:
[0005] A constant pressure check device for a variable frequency pump includes a constant pressure check pipe whose inner end is connected to the outlet end of the variable frequency pump. A pressure tank is fixed on the outer wall of the constant pressure check pipe. The inner cavity of the pressure tank is divided into a pneumatic chamber and a hydraulic chamber by a diaphragm. The hydraulic chamber is connected to the constant pressure check pipe through a pressure through-hole. A check valve assembly is installed in the constant pressure check pipe located inside the pressure through-hole. The check valve assembly can prevent liquid from flowing to the variable frequency pump.
[0006] In the aforementioned constant pressure check device for a variable frequency pump, the constant pressure check pipe includes a constant pressure pipe body and a check pipe body. The inner end of the constant pressure pipe body is connected to the outer end of the check pipe body, and the check pipe body is connected to the water outlet of the variable frequency pump. The pressure tank is installed on the constant pressure pipe body, and the check valve assembly is installed on the check pipe body.
[0007] In the constant pressure check device of the variable frequency pump described above, the inner hole of the check pipe body is a stepped hole and includes a small diameter part and a large diameter part from the inside to the outside. A check positioning step is formed between the small diameter part and the large diameter part. The check valve assembly includes a check valve core that slides axially and can block the small diameter part, and a limiting bracket that is axially fixed between the constant pressure pipe body and the check pipe body. A limiting stroke that restricts the axial displacement of the check valve core is formed between the limiting bracket and the check positioning step.
[0008] In the constant pressure check device of the variable frequency pump described above, the inner end face of the check valve core has three or more guide legs distributed circumferentially and extending into the small diameter portion, and the inner wall surface of the small diameter portion is a conical surface with an inner port diameter larger than the outer port diameter.
[0009] In the constant pressure check device of the variable frequency pump described above, the inner end face of the check valve core is provided with an annular groove, and a sealing ring that can abut against the check positioning step is fitted on the annular groove.
[0010] In the constant pressure check device of the variable frequency pump described above, the inner end of the constant pressure tube and the outer edge of the outer end of the check tube extend radially outward to form an outer mating flange and an inner mating flange, respectively. The mounting nut is sleeved on the constant pressure tube and the check tube from the inside out, and the mounting nut is screwed to the outer mating flange for fixation. The inner wall surface of the mounting nut has a mounting positioning step that can abut against the inner end face of the inner mating flange. The limiting bracket is clamped between the inner end face of the constant pressure tube and the outer end face of the check tube.
[0011] In the constant pressure check device of the variable frequency pump described above, an assembly sealing ring is provided between the inner end face of the constant pressure tube and the outer end face of the check tube, and the assembly sealing ring is located on the outer periphery of the limit bracket shown.
[0012] In the constant pressure check device of the variable frequency pump described above, the pressure tank includes a fixed half shell and an assembly half shell that are spliced together by fasteners. The fixed half shell and the constant pressure check pipe are an integral structure. The outer edge of the diaphragm is clamped between the fixed half shell and the assembly half shell. A hydraulic chamber is formed between the diaphragm and the fixed half shell, and a pneumatic chamber is formed between the diaphragm and the assembly half shell.
[0013] In the constant pressure check device of the variable frequency pump described above, an air inlet is fitted through the wall of the assembly half-shell to connect the air pressure chamber with the outside, and a plug is sealed at the outer port of the air inlet.
[0014] In the constant pressure check device of the variable frequency pump described above, the constant pressure pipe body is a straight pipe structure or a right-angle bend pipe structure.
[0015] The outstanding advantages of this utility model compared to the prior art are:
[0016] This utility model has a simple structure, reasonable design, and low cost. By being installed at the outlet of the variable frequency pump, even if water drips outward from the nozzle when the pump is turned off, the pressure tank can stabilize the water pressure in the pipeline, thereby effectively extending the self-starting time interval of the variable frequency pump. Furthermore, by designing the check valve assembly in the inner pipeline of the pressure tank, the variable frequency pump can be effectively protected, and the pressure tank can also eliminate the impact caused by backflow due to rapid changes in water flow and water pressure. Attached image description:
[0017] Figure 1 This is a cross-sectional view of an embodiment of this utility model;
[0018] Figure 2 This is a cross-sectional view of Embodiment 2 of this utility model.
[0019] In the diagram: 1. Constant pressure check pipe; 2. Pressure tank; 3. Diaphragm; 4. Pressure through-hole; 5. Constant pressure pipe body; 6. Check pipe body; 7. Check valve core; 8. Limiting bracket; 9. Guide support; 10. Sealing ring; 11. External mating flange; 12. Internal mating flange; 13. Assembly nut; 14. Assembly sealing ring; 15. Fixed half shell; 16. Assembly half shell; 17. Air inlet nozzle; 18. Plug. Detailed implementation method:
[0020] The present invention will be further described below with reference to specific embodiments. See also: Figure 1 —2:
[0021] Example 1:
[0022] A constant pressure check device for a variable frequency pump includes a constant pressure check pipe 1 whose inner end is connected to the outlet end of the variable frequency pump. A pressure tank 2 is fixed on the outer wall of the constant pressure check pipe 1. The inner cavity of the pressure tank 2 is divided into an air pressure chamber and a hydraulic chamber by a diaphragm 3. The hydraulic chamber is connected to the constant pressure check pipe 1 through a pressure through hole 4. A check valve assembly is provided in the constant pressure check pipe 1 located inside the pressure through hole 4. The check valve assembly can prevent liquid from flowing to the variable frequency pump.
[0023] This utility model has a simple structure, reasonable design, and low cost. By being installed at the outlet of the variable frequency pump, even if water drips outward from the nozzle when the pump is turned off, the pressure tank 2 can stabilize the water pressure in the pipeline, thereby effectively extending the self-starting time interval of the variable frequency pump. The check valve assembly is designed in the inner pipeline of the pressure tank 2, which can effectively protect the variable frequency pump. At the same time, the pressure tank 2 can eliminate the impact caused by backflow due to rapid changes in water flow and water pressure.
[0024] Furthermore, the specific structure of the constant pressure check pipe 1 is as follows: the constant pressure check pipe 1 includes a constant pressure pipe body 5 and a check pipe body 6. The inner end of the constant pressure pipe body 5 is connected to the outer end of the check pipe body 6, and the check pipe body 6 is connected to the outlet end of the variable frequency pump. The pressure tank 2 is installed on the constant pressure pipe body 5, and the check valve assembly is installed on the check pipe body 6. In this embodiment, the constant pressure pipe body 5 is a right-angle bend, and the inner end of the check pipe body 6 is connected and fixed to the outlet end of the variable frequency pump via threads.
[0025] The check valve assembly can directly use existing commercially available stop valves. However, in this embodiment, to reduce the number of parts and cost, the inner hole of the check pipe body 6 is a stepped hole, and it includes a small diameter section and a large diameter section from the inside out. A check positioning step is formed between the small diameter section and the large diameter section. The check valve assembly includes a check valve core 7 that slides axially and can block the small diameter section, and a limiting bracket 8 that is axially fixed between the constant pressure pipe body 5 and the check pipe body 6. A limiting stroke is formed between the limiting bracket 8 and the check positioning step to limit the axial displacement of the check valve core 7. That is, when the water flows backward, the check valve core 7 moves inward under the action of water pressure, so that the inner end face of the check valve core 7 can abut against and fit against the check positioning step to achieve the blocking of the small diameter section by the check valve core 7; when the variable frequency pump is working, the check valve core 7 moves outward under the action of water pressure, and the limiting bracket 8 can limit the axial outward displacement position of the check valve core 7.
[0026] Furthermore, in order to improve the axial displacement stability of the check valve core 7 relative to the small diameter portion, the inner end face of the check valve core 7 is circumferentially distributed with three or more guide legs 9 extending into the small diameter portion. In addition, in order to prevent the check valve core 7 and the guide legs 9 from tilting and getting stuck in the small diameter portion during axial displacement, the inner wall surface of the small diameter portion is a conical surface with an inner port diameter larger than the outer port diameter. That is, the inner wall surface of the small diameter portion is designed to allow the check valve core 7 and the guide legs 9 to tilt without getting stuck, so as to ensure that the check valve core 7 and the guide legs 9 can perform stable axial displacement.
[0027] Furthermore, in order to improve the sealing performance of the check valve core 7 for the small diameter portion, an annular groove is provided on the inner end face of the check valve core 7, and a sealing ring 10 that can abut against the check positioning step is fitted on the annular groove.
[0028] The pipe connection between the constant pressure pipe 5 and the check pipe 6 can be a common plug-in fixed sleeve method. In this embodiment, the inner end of the constant pressure pipe 5 and the outer edge of the outer end of the check pipe 6 extend radially outward to form an outer mating flange 11 and an inner mating flange 12, respectively. The mounting nut 13 is sleeved from the inside to the outside on the constant pressure pipe 5 and the check pipe 6, and the mounting nut 13 is screwed and fixed to the outer mating flange 11. The inner wall surface of the mounting nut 13 has a mounting positioning step that can abut against the inner end face of the inner mating flange 12. The limiting bracket 8 is clamped between the inner end face of the constant pressure pipe 5 and the outer end face of the check pipe 6.
[0029] Furthermore, in order to ensure the assembly sealing between the constant pressure tube 5 and the check tube 6, an assembly sealing ring 14 is provided between the inner end face of the constant pressure tube 5 and the outer end face of the check tube 6. The assembly sealing ring 14 is located on the outer periphery of the limit bracket 8 shown.
[0030] Meanwhile, to reduce the number of parts, the pressure tank 2 includes a fixed half-shell 15 and an assembly half-shell 16, which are spliced together by fasteners. The fixed half-shell 15 and the constant pressure check pipe 1 are an integral structure. The outer edge of the diaphragm 3 is clamped between the fixed half-shell 15 and the assembly half-shell 16. A hydraulic chamber is formed between the diaphragm 3 and the fixed half-shell 15, and a pneumatic chamber is formed between the diaphragm 3 and the assembly half-shell 16. In order to fill the pneumatic chamber with a certain amount of gas to achieve a predetermined pressure, an air inlet 17 is fitted through the wall of the assembly half-shell 16 to connect the pneumatic chamber to the outside. A plug 18 is sealed at the outer port of the air inlet 17.
[0031] Example 2:
[0032] This embodiment is basically the same in structure as the first embodiment above, except that the constant pressure tube 5 is a straight tube structure.
[0033] The above embodiments are only one of the preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes made in accordance with the shape, structure and principle of this utility model should be covered within the protection scope of this utility model.
Claims
1. A constant pressure check device for a variable frequency pump, characterized in that: It includes a constant pressure check pipe (1) whose inner end is connected to the outlet end of the variable frequency pump. A pressure tank (2) is fixed on the outer wall of the constant pressure check pipe (1). The inner cavity of the pressure tank (2) is divided into a pneumatic chamber and a hydraulic chamber by a diaphragm (3). The hydraulic chamber is connected to the constant pressure check pipe (1) through a pressure through hole (4). A check valve assembly is provided in the constant pressure check pipe (1) located inside the pressure through hole (4). The check valve assembly can prevent liquid from flowing to the variable frequency pump.
2. The constant pressure check device for a variable frequency pump according to claim 1, characterized in that: The constant pressure check pipe (1) includes a constant pressure pipe body (5) and a check pipe body (6). The inner end of the constant pressure pipe body (5) is connected to the outer end of the check pipe body (6). The check pipe body (6) is connected to the outlet of the variable frequency pump. The pressure tank (2) is installed on the constant pressure pipe body (5). The check valve assembly is installed on the check pipe body (6).
3. The constant pressure check device for a variable frequency pump according to claim 2, characterized in that: The inner hole of the check valve body (6) is a stepped hole and includes a small diameter part and a large diameter part from the inside to the outside. A check valve positioning step is formed between the small diameter part and the large diameter part. The check valve assembly includes a check valve core (7) that slides axially and can block the small diameter part, and a limiting bracket (8) that is axially fixed between the constant pressure tube body (5) and the check valve body (6). A limiting stroke that restricts the axial displacement of the check valve core (7) is formed between the limiting bracket (8) and the check valve positioning step.
4. The constant pressure check device for a variable frequency pump according to claim 3, characterized in that: The inner end face of the check valve core (7) has three or more guide feet (9) distributed circumferentially and extending into the small diameter portion. The inner wall surface of the small diameter portion is a conical surface with an inner port diameter larger than the outer port diameter.
5. The constant pressure check device for a variable frequency pump according to claim 3, characterized in that: The inner end face of the check valve core (7) is provided with an annular groove, and a sealing ring (10) that can abut against the check positioning step is fitted on the annular groove.
6. The constant pressure check device for a variable frequency pump according to claim 3, characterized in that: The inner end of the constant pressure tube (5) and the outer edge of the outer end of the check tube (6) extend radially outward to form an outer mating flange (11) and an inner mating flange (12), respectively. The mounting nut (13) is sleeved on the constant pressure tube (5) and the check tube (6) from the inside out, and the mounting nut (13) is screwed and fixed to the outer mating flange (11). The inner wall surface of the mounting nut (13) has a mounting positioning step that can abut against the inner end face of the inner mating flange (12). The limiting bracket (8) is clamped between the inner end face of the constant pressure tube (5) and the outer end face of the check tube (6).
7. The constant pressure check device for a variable frequency pump according to claim 6, characterized in that: An assembly sealing ring (14) is provided between the inner end face of the constant pressure tube (5) and the outer end face of the check tube (6), and the assembly sealing ring (14) is located on the outer periphery of the limit bracket (8) shown.
8. A constant pressure check device for a variable frequency pump according to claim 1 or 2, characterized in that: The pressure tank (2) includes a fixed half shell (15) and an assembly half shell (16) that are spliced together by fasteners. The fixed half shell (15) and the constant pressure check pipe (1) are an integral structure. The outer edge of the diaphragm (3) is sandwiched between the fixed half shell (15) and the assembly half shell (16). A hydraulic cavity is formed between the diaphragm (3) and the fixed half shell (15), and a pneumatic cavity is formed between the diaphragm (3) and the assembly half shell (16).
9. A constant pressure check device for a variable frequency pump according to claim 8, characterized in that: The wall of the assembled half shell (16) is fitted with a gas nozzle (17) that connects the air pressure chamber to the outside. A plug (18) is sealed at the outer port of the gas nozzle (17).
10. A constant pressure check device for a variable frequency pump according to claim 2, characterized in that: The constant pressure pipe body (5) is a straight pipe structure or a right-angle bend pipe structure.