Pneumatic fixed-difference overflow valve

Abstract

The utility model discloses a pneumatic constant-difference overflow valve, which relates to the field of overflow valves, and is characterized by comprising a valve body and an end cover arranged at the top end of the valve body, the lower end of the valve body is provided with a primary side controlled port P connected with a controlled gas pipeline, and the side surface of the valve body is provided with a secondary side main control port T; the end cover is in threaded connection with an adjusting knob which pushes an isolation piston located in the valve body to move up and down, the bottom of the isolation piston is connected with the valve element through a spring, and the compression amount of the spring is changed by moving the isolation piston up and down so as to adjust the pressing force acting on the valve element. According to the overflow valve, under the pure pneumatic environment, on the basis of the pressure difference balance condition that P1 * A is larger than P2 * A + F, the complex logic functions of controlling high pressure through low pressure, valve piece sequential opening, pressure signal comparison and the like are achieved, and the diversified control requirements of special scenes such as explosion prevention are met.

Description

Technical Field

[0001] This utility model relates to the field of overflow valves, and more specifically, it relates to a pneumatic constant differential overflow valve. Background Technology

[0002] With the vigorous development of industrial automation technology, pneumatic technology has been widely used due to its significant advantages such as clean energy, low cost, high safety and fast response speed. At present, pneumatic components and electronic control technology can be combined to realize a variety of automation functions.

[0003] However, in special locations containing explosive gases, such as underground coal mines, the electrical sparks generated by ordinary electrical components pose a risk of gas and dust explosions. Explosion-proof electrical components, on the other hand, suffer from large size, high cost, and inconvenience in movement, making electrical control technology difficult to apply. Although compressed air is readily available in these locations, the variety of existing pneumatic control components is relatively limited. Relying solely on pneumatic technology cannot achieve complex logic control and cannot meet the demands of complex and ever-changing operating conditions. Specifically, conventional pneumatic relief valves are mostly fixed-value relief valves. When the pressure on their primary side (the side directly connected to the controlled gas) reaches the set value, the gas is directly discharged to the atmosphere through the secondary side (the side to which the controlled gas flows after overflowing). This only provides simple overpressure protection and cannot achieve complex logic such as low-pressure control of high-pressure or sequential valve opening through pressure difference control between the primary and secondary sides, severely limiting the application scenarios of purely pneumatic systems.

[0004] Therefore, in order to solve the above-mentioned technical problems, this application proposes a pneumatic constant differential relief valve. Utility Model Content

[0005] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a pneumatic constant differential overflow valve.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a pneumatic differential relief valve, comprising a valve body and an end cap disposed at the top of the valve body. The lower end of the valve body is provided with a primary controlled port P connected to the controlled gas pipeline, and a secondary main control port T is provided on its side. An adjustment knob is threadedly connected to the end cap to push an isolation piston located inside the valve body to move up and down. The bottom of the isolation piston is connected to the valve core through a spring. The clamping force acting on the valve core is adjusted by changing the spring compression by moving the isolation piston up and down.

[0007] The valve core opening condition is that the product of the controlled port pressure P1 and the valve core diameter cross-sectional area A is greater than the sum of the main control port pressure P2 and the valve core diameter cross-sectional area A, and the spring force F, i.e., P1×A>P2×A+F, where F=k×S, K is the spring elastic coefficient, and S is the spring compression distance.

[0008] Preferably, the main control port T is two symmetrically arranged on the side of the valve body, so that one of them can be blocked or used simultaneously as needed.

[0009] Preferably, the valve body is provided with multiple mounting holes for mounting and fixing the differential relief valve.

[0010] Preferably, a groove is formed on the valve core, and a sealing ring A is provided in the groove for sealing between the valve core and the valve body.

[0011] Preferably, a sealing ring B is installed on the isolation piston for sealing between the isolation piston and the valve body.

[0012] Preferably, the adjustment knob has a scale marking on its outer side to display the spring force corresponding to the spring compression.

[0013] Preferably, the end cap is fixed to the valve body by screws.

[0014] Preferably, a locking nut is provided on the outer wall of the adjusting knob to fix the position of the adjusting knob and prevent it from loosening.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. This utility model precisely controls the spring compression by adjusting the knob. In a pure pneumatic environment, based on the pressure difference balance condition of "P1×A>P2×A+F", this overflow valve can realize complex logic functions such as low pressure controlling high pressure, sequential valve opening, and pressure signal comparison, meeting the diverse control needs of special scenarios such as explosion protection. Thus, without the use of electrical control, it can cooperate with conventional pneumatic components and use pure pneumatic control technology to realize some complex logic control, thereby solving the problems in the background technology.

[0017] 2. In this utility model, after the adjustment knob is rotated to the target differential pressure setting position, the state of the adjustment knob is fixed by the locking nut to prevent the adjustment knob from rotating due to external disturbances, thereby maintaining the preset compression amount S of the compression spring unchanged.

[0018] 3. The symmetrically distributed dual main control ports T of this utility model can meet diverse pipeline connection needs: users can choose to block one of the T ports or use both T ports at the same time according to the actual layout, which is especially suitable for industrial environments with limited space or requiring multiple gas sources.

[0019] 4. This utility model transforms the abstract spring compression into an intuitive pressure value. Operators can directly obtain the currently set spring force by observing the scale without the need for additional tools or complex calculations, thus avoiding accuracy deviations caused by adjustment based on experience. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0022] Figure 2 This is an overall sectional view of the present invention.

[0023] In the diagram: 1. Valve body; 2. Flip cover; 3. Adjustment knob; 4. Isolation piston; 5. Spring; 6. Valve core; 7. Sealing ring A; 8. Sealing ring B; 9. Mounting hole; 10. Locking nut; 11. Screw. (The controlled port P and the main control port T are represented by the letters P and T in the attached diagram.) Detailed Implementation

[0024] like Figure 1-2 As shown, this utility model provides a pneumatic differential relief valve, including a valve body 1 and an end cap 2 disposed at the top of the valve body 1. The lower end of the valve body 1 is provided with a primary controlled port P connected to the controlled gas pipeline, and a secondary main control port T is provided on its side. An adjustment knob 3 is threadedly connected to the end cap 2 to push the isolation piston 4 located inside the valve body 1 to move up and down. The bottom of the isolation piston 4 is connected to the valve core 6 by a spring 5. The clamping force acting on the valve core 6 is adjusted by changing the compression of the spring 5 by moving the isolation piston 4 up and down. The valve core 6 has a groove, and a sealing ring A7 is provided in the groove for sealing between the valve core 6 and the valve body 1. The valve body 1 is provided with multiple mounting holes 9 for mounting and fixing the differential relief valve. The end cap 2 is fixed to the valve body 1 by screws 11.

[0025] The valve core 6 is opened when the product of the pressure P1 at the controlled port P and the cross-sectional area A of the valve core 6 is greater than the sum of the product of the pressure P2 at the main control port T and the cross-sectional area A of the valve core 6 and the spring force F, i.e., P1×A>P2×A+F, where F=k×S, K is the elastic coefficient of the spring 5, and S is the compression distance of the spring 5.

[0026] The controlled port P at the lower end of valve body 1 is connected to the controlled gas pipeline (pressure position P1), and the main control port T on the side is connected to the secondary gas pipeline (pressure P2). It should be noted that both the controlled port P and the main control port T are threaded holes, which can be quickly adapted to mainstream gas pipe connectors and fittings without the need for customized parts, thus improving system compatibility. Before the valve core 6 is opened, the valve core 6 is pressed together with the chamfer of valve body 1 under the action of spring force. The sealing ring A7 on the valve core 6 fits with the chamfer sealing surface of valve body 1 to form an initial sealing state. The cavity located at the upper end of valve core 6 inside valve body 1 is connected to the main control port T, so that P2 acts on the upper end of valve core 6. At the same time, spring 5 is also compressed, transmitting the spring force F to the upper end of valve core 6, which together with P2 forms a reverse resultant force (P2×A+F, where A is the cross-sectional area of ​​valve core 6). Adjusting knob 3 is connected to end cap 2 via a thread. Rotating adjusting knob 3 causes the screw on adjusting knob 3 to push the isolation piston 4 up and down, changing the compression S of spring 5, thereby adjusting the spring force F (F=k×S, k is the elastic coefficient of spring 5), and setting the opening pressure difference of valve core 6. When the pressure P1 of the controlled port P increases to the point that the force (P1×A) acting on the lower end of valve core 6 is greater than the reverse resultant force, valve core 6 overcomes the resistance and moves upward, connecting the controlled port P with the main control port T, and the gas enters the overflow state: if the main control port T is connected to a low-pressure gas path or the atmosphere, the high-pressure gas of the controlled port P overflows through the main control port T, resulting in a decrease in the pressure of the controlled port P; if the main control port T is connected to a load gas path, the gas of the controlled port P charges the main control port T, which can increase the pressure of the main control port T. Therefore, depending on the valve or pipeline connected to the controlled port P and the main control port T, this state can achieve the following: The pressure value at the control port P decreases or the pressure value at the main control port T increases, thus satisfying different working conditions. By adjusting the knob 3 to precisely control the compression of the spring 5, this relief valve can achieve complex logic functions such as low pressure controlling high pressure, sequential valve opening, and pressure signal comparison in a purely pneumatic environment based on the pressure difference balance condition of "P1×A>P2×A+F". This meets the diverse control needs of special scenarios such as explosion-proof. Therefore, without the use of electrical control, it can be used with conventional pneumatic components to achieve some complex logic control using pure pneumatic control technology.

[0027] In summary, the overflow valve provided by this utility model differs from traditional overflow valves that rely on single pressure control. The secondary side of this overflow valve is connected to a gas with a different pressure value than the controlled gas (primary side). When used in conjunction with existing conventional pneumatic pressure reducing valves, check valves, and other control-type pneumatic valves, it can realize complex pressure control logic and has a wide range of application prospects in dangerous locations such as underground coal mines.

[0028] Furthermore, firstly, a locking nut 10 is provided on the outer wall of the adjusting knob 3 to fix its position and prevent it from loosening. This design can effectively resist common interference factors in industrial environments such as vibration, impact, or air pressure fluctuations. When the adjusting knob 3 is rotated to the target differential pressure setting position, the locking nut 10 fixes the state of the adjusting knob 3, preventing it from rotating due to external disturbances, thereby maintaining the preset compression amount S of the compression spring 5 unchanged. This design is particularly important in harsh environments such as underground coal mines: without the locking nut 10, the adjusting knob 3 may gradually loosen due to equipment vibration, causing the spring force F to change, which in turn causes the differential pressure of the valve core 6 to deviate from the set value, leading to pressure control failure or malfunction. The presence of the locking nut 10 ensures that the valve maintains a precise differential pressure threshold during long-term operation, improving the safety and stability of the entire pneumatic system.

[0029] Secondly, the main control ports T are symmetrically arranged on the side of the valve body 11. The symmetrical distribution of the dual main control ports T can meet diverse pipeline connection requirements: users can choose to block one of the T ports (single-path control scenario, simplifying connection) or use both T ports simultaneously (dual-path redundancy or pressure-dividing control scenario, enhancing system flexibility) according to the actual layout. This is especially suitable for industrial environments with limited space or requiring multiple gas source access (such as compact installation of equipment in underground coal mines). At the same time, the symmetrical structure ensures that the gas pressure at the upper end of the valve core 6 is evenly applied to the entire end face, avoiding the problem of uneven load on the valve core 6 caused by unilateral air intake, effectively reducing the risk of seal wear and seal failure, and improving differential pressure control accuracy and valve service life.

[0030] Furthermore, a sealing ring B8 is installed on the isolation piston 4 to seal the gap between the isolation piston 4 and the valve body 1. As a key component in the regulating mechanism that transmits the compression of the spring 5, if the clearance between the isolation piston 4 and the valve body 1 lacks an effective seal, the gas (pressure P2) at the main control port T will leak, causing the actual force on the upper end of the valve core 6 to deviate from the design value. This will lead to a deviation between the theoretical calculation and actual control of the valve core 6 opening pressure differential, resulting in malfunction or control failure of the overflow valve. The presence of the sealing ring B8 can completely block the gas leakage path, ensuring that the pressure P2 at the main control port T acts stably on the upper end of the valve core 6, forming a precise resultant force (P2×A+F) with the compression spring force F, ensuring that the valve core 6 opening condition (P1×A>P1×A+F) strictly follows the design logic.

[0031] Finally, the adjustment knob 3 has scale markings on its outer side. This design transforms the abstract spring compression (S) into an intuitive pressure value. Operators can directly obtain the currently set spring force by observing the scale without the need for additional tools or complex calculations, thus avoiding accuracy deviations caused by adjustment based on experience.

[0032] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model in any way. Those skilled in the art can readily implement this utility model based on the accompanying drawings and the above description. However, any modifications, alterations, or equivalent variations made by those skilled in the art without departing from the scope of the utility model's technical solution, utilizing the disclosed technical content, are considered equivalent embodiments of this utility model. Furthermore, any equivalent changes, alterations, or variations made to the above embodiments based on the essential technology of this utility model are still within the protection scope of this utility model's technical solution.

Claims

1. A pneumatic differential relief valve, comprising a valve body (1) and an end cap (2) disposed at the top of the valve body (1), characterized in that: The lower end of the valve body (1) is provided with a primary side controlled port P that connects to the controlled gas pipeline, and a secondary side main control port T is provided on its side. The end cap (2) is threaded with an adjustment knob (3) that pushes the isolation piston (4) located inside the valve body (1) to move up and down. The bottom of the isolation piston (4) is connected to the valve core (6) through a spring (5). The clamping force acting on the valve core (6) is adjusted by changing the compression of the spring (5) by moving the isolation piston (4) up and down. The valve core (6) is opened when the product of the pressure P1 at the controlled port P and the cross-sectional area A of the valve core (6) is greater than the sum of the product of the pressure P2 at the main control port T and the cross-sectional area A of the valve core (6) and the spring force F, i.e., P1×A>P2×A+F, where F=k×S, K is the elastic coefficient of the spring (5), and S is the compression distance of the spring (5).

2. The pneumatic differential relief valve according to claim 1, characterized in that: The number of main control ports T is two, symmetrically arranged on the side of the valve body (1), and one of them can be blocked or used simultaneously as needed.

3. A pneumatic differential relief valve according to claim 1, characterized in that: The valve body (1) is provided with multiple mounting holes (9) for mounting and fixing the differential relief valve.

4. A pneumatic differential relief valve according to claim 1, characterized in that: The valve core (6) has a groove, and a sealing ring A (7) is provided in the groove for sealing between the valve core (6) and the valve body (1).

5. A pneumatic differential relief valve according to claim 1, characterized in that: A sealing ring B (8) is installed on the isolation piston (4) for sealing between the isolation piston (4) and the valve body (1).

6. A pneumatic differential relief valve according to claim 1, characterized in that: The adjustment knob (3) has a scale mark on its outer side to display the spring force corresponding to the compression amount of the spring (5).

7. A pneumatic differential relief valve according to claim 1, characterized in that: The end cap (2) is fixed to the valve body (1) by screws (11).

8. A pneumatic differential relief valve according to claim 1, characterized in that: A locking nut (10) is provided on the outer wall of the adjustment knob (3) to fix the position of the adjustment knob (3) and prevent it from loosening.

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