Negative pressure pneumatic control valve triggered by liquid level

Abstract

The negative pressure pneumatic control valve is provided with a liquid level positive pressure cavity, a throttling timing cavity, an atmosphere cavity, a negative pressure execution cavity and a negative pressure source cavity which are sequentially distributed up and down, the liquid level positive pressure cavity and the throttling timing cavity are separated through a liquid level diaphragm, the liquid level positive pressure cavity is provided with a liquid level connector, and the atmosphere cavity is provided with an atmosphere connector. The negative pressure executing cavity is provided with a negative pressure executing mechanism connector, the negative pressure source cavity is provided with a negative pressure air source connector, the negative pressure executing valve element, the first annular sealing piece and the second annular sealing piece form corresponding valve sealing pairs, the upper portion of the liquid level valve element is fixedly connected to the center of the liquid level diaphragm, and the lower end of the liquid level valve element is connected with the top end of the negative pressure executing valve element. And the negative pressure execution cavity is communicated with the communicating throttling timing cavity through a negative pressure execution channel. The device is controlled by the liquid level, has a pressure comparison function and a delay timing function, avoids troubles caused by electrical and electronic equipment, and is mainly applicable to occasions such as a negative pressure sewage conveying system and the like.

Description

Technical Field

[0001] The present invention relates to a liquid level triggered negative pressure pneumatic control valve, belonging to the technical field of automatic control, and can be mainly used for the automatic control of a sewage negative pressure conveying system. Background Art

[0002] A sewage negative pressure conveying system is provided with a water collecting tank and a negative pressure conveying pipeline. One end of the negative pressure conveying pipeline is connected to the water collecting tank, and the other end is connected to a negative pressure tank. Usually, source sewage can be collected into the water collecting tank by means of gravity flow, etc. When the water level in the water collecting tank rises to a certain level, the valve on the negative pressure conveying pipeline is opened through a control device, and the sewage in the water collecting tank is pumped into the negative pressure tank by relying on the negative pressure of the negative pressure tank. When the water level in the water collecting tank drops to a certain limit, the valve on the negative pressure conveying pipeline is closed through the control device. Most of the existing control devices adopt electronic equipment. A liquid level sensor is provided on the water collecting tank, and the liquid level sensor transmits the liquid level signal to the control device in the form of an electric signal. The control device analyzes and processes the electric signal, and when the corresponding conditions are met, a control signal is sent to the valve on the negative pressure conveying pipeline to control the valve action. The valve on the negative pressure conveying pipeline can be an electric valve or a negative pressure valve. When a negative pressure valve is adopted, the control device opens the control valve on the negative pressure control pipeline of the negative pressure valve through an electric control method, and the negative pressure is connected to the control end of the negative pressure valve through the negative pressure control pipeline, thereby controlling the action of the negative pressure valve. This electric control method is effective and feasible under certain conditions, but there are certain limitations. For example, the water collecting tank and the negative pressure conveying pipeline are mostly in a humid environment, which is not conducive to the safety of electricity use and the protection of electronic equipment. In addition, especially in the case where the sewage sources are scattered, it is necessary to lay circuits or power supplies over a long distance or a large area, and the workload of construction and maintenance is large, and the reliability of the system operation is relatively low. Summary of the Invention

[0003] The purpose of the present invention is to adopt liquid level / air pressure for control to avoid the troubles brought by electrical and electronic equipment.

[0004] The technical solution of the present invention is: a liquid-level-triggered negative-pressure pneumatic control valve, which is provided with a liquid-level positive-pressure chamber, a throttling timing chamber, an atmosphere chamber, a negative-pressure actuator chamber and a negative-pressure source chamber that are distributed vertically in sequence. The liquid-level positive-pressure chamber and the throttling timing chamber are separated by a liquid-level diaphragm. The liquid-level positive-pressure chamber is provided with (for example, installed with) a liquid-level interface for connecting a liquid-level induction pipe to access the air pressure (gas with corresponding pressure) that is positively correlated with the liquid level. The atmosphere chamber is provided with (for example, provided with or installed with) an atmosphere interface for communicating with the atmosphere. The negative-pressure actuator chamber is provided with (for example, installed with) a negative-pressure actuator interface for connecting a negative-pressure actuator (the negative-pressure control end of the negative-pressure actuator). The negative-pressure source chamber is provided with (for example, installed with) a negative-pressure gas source interface for connecting a negative-pressure gas source. A first annular seal is provided at the center of the separating structure between the atmosphere chamber and the negative-pressure actuator chamber (the structure located between the two chambers and separating the two chambers, usually horizontally arranged, using a flat plate or a structure similar to a flat plate, or called a partition). A second annular seal is provided at the center of the separating structure between the negative-pressure actuator chamber and the negative-pressure source chamber. The negative-pressure actuator valve core is arranged vertically, passes through the central through holes of the first annular seal and the second annular seal, and forms a first valve seal pair (a seal pair that can be opened and closed) and a second valve seal pair with the first annular seal and the second annular seal respectively. When the negative-pressure actuator valve core is at a high position, the first valve seal pair is opened and the second valve seal pair is closed. When the negative-pressure actuator valve core is at a low position, the first valve seal pair is closed and the second valve seal pair is opened. The liquid-level valve core is arranged vertically, its upper part is fixedly connected to (or called installed on) the center of the liquid-level diaphragm, and the lower end extends out of the throttling timing chamber and is connected to (for example, in contact with) the top end of the negative-pressure actuator valve core. The liquid-level valve core and the negative-pressure actuator valve core are respectively provided with a first spring and a second spring serving as their respective return springs. The first negative-pressure actuator channel communicating with the negative-pressure actuator chamber is communicated with the second negative-pressure actuator channel communicating with the throttling timing chamber.

[0005] Further, the first spring and the second spring can adopt pre-compressed helical springs or other suitable springs, which respectively apply an upward thrust to the liquid-level valve core and the negative-pressure actuator valve core. The initial positions of the liquid-level valve core and the negative-pressure actuator valve core are their respective high positions (the positions at the higher part during the working stroke), and this state is the closed state of the pneumatic control valve, which can be regarded as the normal state. Correspondingly, in the open state of the pneumatic control valve, the positions of the liquid-level valve core and the negative-pressure actuator valve core are their respective low positions (the positions at the lower part during the working stroke).

[0006] Further, the negative-pressure actuator valve core can adopt a non-uniform-diameter cylindrical shape (a cylindrical shape with an annular convex-concave structure / step structure on the circumferential surface) to achieve sealing or non-sealing (opening) with the first annular seal and the second annular seal at each set position (high position or low position).

[0007] Each annular seal is provided with a central through-hole, and the negative pressure actuating valve core passes through the central through-holes of these annular seals. When the outer diameter of the negative pressure actuating valve core located in the central through-hole of any seal is smaller than the inner diameter of the central through-hole, there is a gap between the two, allowing fluid (e.g., air) to pass through, and the corresponding valve sealing pair is in an open state; when the outer diameter of the negative pressure actuating valve core located in any central through-hole is larger than the inner diameter of the central through-hole, the central through-hole of the annular seal is expanded and tightly attached (fastened) to the negative pressure actuating valve core, there is no gap between the two, and fluid (e.g., air) is not allowed to pass through, and the corresponding valve sealing pair is in a closed state. Therefore, the outer diameter of the negative pressure actuating valve core at relevant positions (areas) can be appropriately set to ensure that when the negative pressure actuating valve core is at a specific position (high or low), the relevant valve sealing pairs are in the proper open or closed state. The outer diameter of the negative pressure actuating valve core should be avoided from being too large, so as to avoid hindering the movement of the negative pressure actuating valve core due to excessive force / resistance of the annular seal on the valve core while ensuring sealing. The liquid level valve core seal has the same or similar structure as the annular seal, and the area where the liquid level valve core contacts the central through-hole of the liquid level valve core seal during the working stroke is of equal diameter, so that the liquid level valve core seal always maintains the seal with the liquid level valve core.

[0008] The liquid level valve core moves vertically with the vertical movement of the liquid level diaphragm (the part of the liquid level diaphragm connected to the liquid level valve core). The liquid level diaphragm will deform due to the pressure difference on both sides, with the middle part moving downward, thereby driving the liquid level valve core to move downward from the high position to the low position, and then driving the negative pressure actuating valve core to move downward from the high position to the low position through the liquid level valve core, realizing the switching between the high and low positions of the negative pressure actuating valve core, and thus realizing the synchronous switching of the states of the first valve sealing pair and the second valve sealing pair.

[0009] The above structure can be integrally set as a liquid level trigger module and a negative pressure actuating module. Among them, the liquid level positive pressure chamber and the throttling timing chamber are integrated into the liquid level trigger module, and the atmosphere chamber, the negative pressure actuating chamber and the negative pressure source chamber are integrated into the negative pressure actuating module.

[0010] Preferably, a two-way valve unit (or two-way valve) is provided on the side wall of the throttling timing chamber. The two-way valve unit is provided with a valve sealing pair that closes when the pressure difference between the outside and the inside exceeds the limit (closes / seals when the difference between the outside pressure and the inside pressure exceeds the set limit value). Thus, when the pressure difference between the outside and the inside does not exceed the limit, the two-way valve unit conducts bidirectionally, and when the amplitude of the outside pressure being greater than the inside pressure exceeds the set limit value, the two-way valve unit closes.

[0011] Preferably, the two-way valve unit is provided with a two-way valve medium channel. The inner end of the two-way valve medium channel opens into the throttling timing chamber, and the outer port communicates with the atmosphere. The two-way valve medium channel is provided with a two-way valve ball, a two-way valve sealing ring, a two-way valve outer spring, and a two-way valve inner spring. The two-way valve sealing ring (that is, the valve seat of the corresponding valve sealing pair) is installed on the two-way valve medium channel inside the two-way valve ball (it can be installed by setting an annular stepped end face, a groove, and an annular pressing plate, etc. on the corresponding medium channel, or other installation methods of the valve sealing seat can also be used), and forms a valve sealing pair that closes when the pressure difference between the outside and inside exceeds the limit with the two-way valve ball. The two-way valve outer spring and the two-way valve inner spring are respectively located outside and inside the two-way valve ball, with one end (the valve ball end) acting on the valve ball and the other end (the end far from the valve ball) acting on the two-way valve medium channel (for example, clamped, abutted, or fixedly connected to the side wall or the outer end of the two-way valve connecting channel). When the valve ball is not affected by other external forces, the outer spring and the inner spring make the valve ball located in the middle of the medium channel (when the valve ball is in the middle of the medium channel, the thrust of the two springs on the valve ball reaches balance). When the difference between the outside air pressure (atmospheric pressure) and the inside air pressure (the air pressure in the throttling timing chamber) is less than the set limit value (the limit value for achieving sealing), the two-way valve ball does not contact the two-way valve sealing ring, and the two-way valve unit is opened. When the difference between the outside air pressure and the inside air pressure exceeds the set limit value, the valve ball moves inward under the combined action of the pressure difference and the two springs to the position where it is in sealed contact with the two-way valve sealing ring (achieving the sealed contact), thereby closing the two-way valve unit. The two springs (elastic coefficient, length, etc.) and other structural features (for example, the position of the two-way valve sealing ring) can be reasonably selected to meet the above requirements.

[0012] Preferably, a throttling timing unit is provided on the side wall of the throttling timing chamber. The throttling timing unit is provided with a throttling medium channel. The inner end of the throttling medium channel opens into the throttling timing chamber to form a throttling outlet, and the outer port of the throttling medium channel communicates with the atmosphere to form a throttling inlet.

[0013] Preferably, the throttling timing unit is provided with a timing adjustment knob for adjusting the throttling resistance.

[0014] Preferably, throttle timing holes are provided on the side wall of the throttle timing chamber (which can be directly opened at a suitable position on the side wall of the throttle timing chamber, or a cylindrical throttle timing unit housing can be hermetically embedded / fixedly installed on the side wall of the throttle timing chamber, and the through hole on the throttle timing unit housing is used as the throttle timing hole). The outer end (the area near the outer port) of the throttle timing hole is provided with internal threads. The front part of the timing adjustment knob is located in the throttle timing hole, and an annular gap forming a throttle medium channel is provided between the timing adjustment knob and the throttle timing hole. The rear part of the timing adjustment knob is provided with external threads and is threadedly connected to the internal threads on the throttle timing hole. A side wall through hole forming a throttle inlet is opened on the hole wall of the throttle timing hole. The inner end of the side wall through hole communicates with the annular gap between the front part of the timing adjustment knob and the throttle timing hole, and the outer end communicates with the atmosphere. By rotating the timing adjustment knob, the effective length of the throttle medium channel (the length between the inner end of the annular gap and the side wall through hole) can be adjusted, the resistance of the throttle timing unit can be adjusted, and further the time for the throttle timing chamber to return to normal pressure (or close to normal pressure) through the throttle timing unit under a certain negative pressure state can be adjusted.

[0015] Preferably, the liquid level diaphragm is in a shape of a rotating curved surface, and its middle radial part (the part between the central part and the edge part) is convex downward (in the normal state, that is, the state where the pressure difference between both sides is zero).

[0016] Preferably, a liquid level valve core through hole is provided on the bottom surface (or bottom plate) of the throttle timing chamber, and a liquid level valve core seal is provided. The liquid level valve core seal is an annular seal, and its periphery (outer edge) is hermetically connected to the bottom surface of the throttle timing chamber. The liquid level valve core passes through the central through hole of the liquid level valve core seal and the liquid level valve core through hole, and is hermetically connected to the central through hole of the liquid level valve core seal (the hole wall of the central through hole of the liquid level valve core seal closely adheres to / grips the liquid level valve core), thereby realizing the seal between the liquid level valve core and the bottom surface of the throttle timing chamber.

[0017] Preferably, one or more limiting and locking mechanisms (or limiting and locking modules) are provided in the upper part of the air cavity. A radially extending limiting and locking channel is provided in the housing of the limiting and locking mechanism. A locking ball and a locking spring are provided in the limiting and locking channel. The locking spring is located outside the locking ball (radially outside), and its inner end acts on the locking ball, pushing the locking ball inward. Two upper and lower limiting and locking annular grooves corresponding to the locking ball are provided on the negative pressure actuating valve core (on the circumferential surface of the negative pressure actuating valve core). The lower limiting and locking annular groove can be called the first limiting and locking, and the upper limiting and locking annular groove can be called the second limiting and locking. An annular protrusion (an annular protrusion structure relative to the annular groove) is provided between the two limiting and locking annular grooves. When any one of the limiting and locking annular grooves is at the same height as the locking ball, the locking ball is partially engaged in the limiting and locking annular groove under the push of the corresponding locking spring, thereby restricting the position of the negative pressure actuating valve core. The first limiting and locking (the lower limiting and locking annular groove) restricts the negative pressure actuating valve core at its high position, and the second limiting and locking (the upper limiting and locking annular groove) restricts the negative pressure actuating valve core at its low position.

[0018] The number of the limiting and locking mechanisms can be two, three or more, and they are equally spaced to achieve balanced locking force and simplify the structure as much as possible.

[0019] Preferably, a locking adjustment knob (cylindrical part) is threadedly connected to the outer end of the limiting and locking channel, and the outer end of the locking spring abuts against the locking adjustment knob. Thus, rotating the locking adjustment knob can change the compression degree of the locking spring, and further adjust the limiting and locking force on the negative pressure actuating valve core.

[0020] Various specific connection structures and other supporting structures can be set according to actual needs. For example, a manual start diaphragm is provided in the center of the top surface (top plate) of the liquid level positive pressure cavity. The manual start diaphragm is an elastic diaphragm, and its radially middle part (the part between the central part and the edge part) protrudes upward. The bottom surface (lower surface) of the central part contacts the top end of the liquid level valve core.

[0021] Furthermore, the periphery of the manual start diaphragm is hermetically connected to the top surface of the liquid level positive pressure cavity. The central part is flat or has other shapes suitable for manual pressing. The top of the liquid level valve core applies a certain pre-compression to the manual start diaphragm (that is, if not restricted by the liquid level valve core, the bottom surface height of its central part will be lower than the top end height of the liquid level valve core). Thus, the manual start diaphragm can rely on its own elasticity to keep the contact between its central part and the top surface of the liquid level valve core.

[0022] The beneficial effects of the present invention are as follows: An air control valve is used as the control device for the negative pressure valve on the negative pressure conveying pipeline. According to the water level in the water collection tank / the pressure change in the induction pipe, the on-off of each air circuit in the air control valve is realized. After the water level in the water collection tank reaches a certain height, a negative pressure signal is automatically output, thereby controlling the opening of the negative pressure valve on the negative pressure conveying pipeline. And after a certain timing time, the output of the negative pressure signal is automatically stopped, and the negative pressure valve on the negative pressure conveying pipeline is closed. Thus, while meeting the control requirements, there is no need to set up a power supply, electrical and electronic equipment, fundamentally avoiding the problem of electrical safety, saving the construction volume of circuit and power supply layout, and saving the maintenance work of electrical and electronic equipment; The throttling timing unit and the two-way valve unit are arranged in the throttling timing cavity, with high integration, which is conducive to further simplifying the product structure; Since the negative pressure of the negative pressure conveying system is used as the power source for control, and through an integrated valve design, the on-site assembly is simple and fast, and no additional site is required; Due to the reasonable design of the air control valve and the allowable selection of materials suitable for humid environments, it operates reliably, has low maintenance requirements, and a long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the system structure of a usage mode of the present invention; Figure 2 is a schematic diagram of the structure of the present invention (negative pressure cut-off state); Figure 3 is a schematic diagram of the structure of the present invention (negative pressure connected state); Figure 4 is a schematic diagram of the structure of the present invention (throttling timing state); Figure 5 is a schematic diagram of the structure of the liquid level trigger module of the present invention (initial / closed state); Figure 6 is a schematic diagram of the structure of the liquid level trigger module of the present invention (open state); Figure 7 is a schematic diagram of the structure of the limit locking module of the present invention (first limit locking state); Figure 8 is a schematic diagram of the structure of the limit locking module of the present invention (intermediate state); Figure 9 is a schematic diagram of the structure of the limit locking module of the present invention (second limit locking state); Figure 10 is a schematic diagram of the structure of the limit locking module and the negative pressure execution module of the present invention (negative pressure cut-off state); Figure 11 is a schematic diagram of the structure of the limit locking module and the negative pressure execution module of the present invention (negative pressure connected state); Figure 12 is based on Figure 5Schematic diagram of the installation structure of an elastic diaphragm or similar component taking part B shown as an example.

[0024] Markings in the figure: 1. Pneumatic control valve; 2. Negative pressure actuator (usually a negative pressure valve); 3. Water collecting tank; 4. Induction pipe; 5. Induction pipe connecting pipe; 6. Drain pipe; 7. Negative pressure pipeline; 8. Negative pressure air source intake port; 9. Negative pressure source connecting pipe; 10. Liquid level trigger module; 101. Manual start diaphragm; 102. Liquid level positive pressure chamber; 103. Liquid level diaphragm; 104. Throttle timing chamber; 105. Liquid level valve core seal; 106. Liquid level valve core; 107. First spring; 11. Two-way valve unit; 111. Two-way valve sealing ring; 112. Outer spring of two-way valve; 113. Two-way valve ball; 114. Inner spring of two-way valve; 12. Throttle timing unit; 121. Throttle outlet; 122. Throttle channel; 123. Throttle inlet; 124. Timing adjustment knob; 131. Connection part; 132. Connection base; 133. Connection pressing plate; 20. Limit locking module; 201. Negative pressure actuator valve core; 202. Second spring; 203. Locking ball; 204. Locking adjustment knob; 205. Locking spring; 206. First limit lock; 207. Second limit lock; 30. Negative pressure actuator module; 301. Atmosphere chamber; 302. First annular seal; 303. Negative pressure actuator chamber; 304. Second annular seal; 305. Negative pressure source chamber; 31. Negative pressure detection unit; 311. Negative pressure detection unit sealing ring; 312. Negative pressure detection unit valve ball; 313. Negative pressure detection unit spring; A. Atmosphere interface; A1. First atmosphere channel; A2. Second atmosphere channel; A3. Third atmosphere channel; P. Negative pressure air source interface; V. Negative pressure actuator interface; V1. First negative pressure actuator channel; V2. Second negative pressure actuator channel, L. Liquid level interface. Specific implementation mode

[0025] See Figure 1, this pneumatically controlled valve 1 can be regarded as a pneumatically controlled two-way three-way valve with pressure comparison function and delay timing function. It determines its working position according to the air pressure applied to the control end. Its common interface (multi-port) is the negative pressure actuator interface V, which is used to connect the negative pressure actuator (usually a negative pressure valve on the negative pressure conveying pipeline) 2. Among the two single ports, one is the atmosphere interface A, and the other is the negative pressure air source interface P. The negative pressure air source interface P is connected to the negative pressure air source intake port 8 on the negative pressure pipeline 7 through the negative pressure source connecting pipe (air pipe) 9. The water collection tank (or called sump, water collection well, water collector, water storage tank, etc.) 3 for collecting sewage is provided with an induction pipe 4 for sensing the water level (or called liquid level) in the tank. The induction pipe 4 can be a vertical pipe with a closed top and an open bottom. The top is provided with an induction interface and is connected to the liquid level interface L of the pneumatically controlled valve 1 through the induction pipe connecting pipe (air pipe) 5. When the water level in the tank is lower than the open bottom of the induction pipe, the air in the induction pipe is at normal pressure. Therefore, the liquid level interface L of the pneumatically controlled valve 1 is connected to the normal pressure. In this case, the negative pressure actuator interface V of the pneumatically controlled valve 1 is connected to the atmosphere interface A, and the air pressure applied to the control end of the negative pressure actuator 2 is normal pressure, and the negative pressure actuator 2 does not start (the negative pressure valve is closed). When the water level in the water collection tank exceeds the open bottom of the induction pipe, as the water level in the water collection tank continues to rise, the gas pressure in the upper part of the induction pipe also continues to rise. When this pressure reaches or exceeds a certain value, the negative pressure actuator interface V of the pneumatically controlled valve 1 is connected to the negative pressure air source interface P, and the air pressure applied to the control end of the negative pressure actuator 2 is the negative pressure of the negative pressure source. The negative pressure actuator 2 starts (the negative pressure valve opens). Under the negative pressure action of the negative pressure pipeline 7, the sewage in the water collection tank is pumped into the negative pressure pipeline 7 through the drain pipe 6 and sent to the negative pressure station.

[0026] See Figures 2 to 11 , this pneumatically controlled valve includes three functional modules, which are respectively: (1) the liquid level trigger module, with 2 functional units built in, namely the two-way valve unit 11 and the throttling timing unit 12; (2) the limit locking module; (3) the negative pressure execution module, with 1 functional unit built in, namely the negative pressure detection unit 31.

[0027] The working process and working principle of each module are as follows: I. Liquid level trigger module Initial / closed state: The liquid level interface L has no pressure (normal pressure), that is, it is connected to the atmosphere, and the liquid level positive pressure chamber 102 is at normal pressure. The second negative pressure execution channel V2 is connected to the third atmosphere channel A3. The valve ball 113 in the two-way valve unit (or called two-way valve) 11 is in the middle position under the same pressure of the outer spring 112 and the inner spring 114, and is disengaged from the seal of the sealing ring 111, so that the atmosphere channel A1 is connected to the throttling timing chamber 104, and the throttling timing chamber 104 is at normal pressure.

[0028] Liquid level opening (liquid level trigger) state: The pressure connected to the liquid level interface L increases as the liquid level in the water collection tank / induction pipe rises. The set liquid level height for liquid level trigger is H. When this liquid level is reached, the air pressure in the liquid level positive pressure chamber 102 increases to a sufficient level. Under this pressure, the liquid level diaphragm 103 drives the liquid level valve core 106 to move downward against the resistance of the first spring 107, and then pushes the negative pressure actuating valve core 201 to actuate and perform a position change, conducting the negative pressure source. The negative pressure source passes through the first negative pressure actuating channel V1 (connected to the negative pressure actuating mechanism interface V) and communicates with the second negative pressure actuating channel V2. The valve ball 113 of the two-way valve unit is pressed against the sealing ring 111 under negative pressure to achieve sealing, and the throttling timing chamber 104 is in a negative pressure state, maintaining the liquid level valve core 106 and the negative pressure actuating valve core 201 in the open position. The negative pressure actuating mechanism interface V connects the negative pressure to the air pressure control end of the actuating mechanism, enabling the negative pressure actuating mechanism to be in the open state, and the negative pressure pipeline 7 extracts the sewage in the water collection tank.

[0029] When the liquid level (the liquid level that allows the sewage to enter the drain pipe) disappears, the liquid level positive pressure chamber 102 is at normal pressure. The atmosphere enters the negative pressure pipeline 7 from the drain pipe 6 through the negative pressure air source intake port 8. The negative pressure at the negative pressure air source intake port 8 drops, and the negative pressure detection unit 31 of the pneumatic control valve closes, equivalent to the closing of the negative pressure air source, and the throttling timing starts. The atmosphere enters the throttling timing chamber 104 through the second atmosphere channel A2 and the throttling timing unit (a throttle valve for timing) 12. The negative pressure in the chamber gradually decreases. When the two-way valve unit 11 opens (conducts), the atmosphere directly enters the throttling timing chamber 104 through the first atmosphere channel A1. Under the action of the first spring 107, the liquid level valve core 106 returns to its position, the negative pressure actuating valve core 201 returns to its position, the pneumatic control valve closes, the negative pressure air source at the pressure control end of the negative pressure actuating mechanism is cut off, and it communicates with the third atmosphere channel A3, and the negative pressure actuating mechanism is cut off.

[0030] The two-way valve unit 11 is integrated into the liquid level trigger module 10, with one end (one end of the medium channel) communicating with the throttling timing chamber 104 and one end communicating with the first atmosphere channel A1. In the negative pressure cut-off state, the first negative pressure actuating channel V1 communicates with the third atmosphere channel A3, and the atmosphere communicates with the throttling timing chamber 104 through the second negative pressure actuating channel V2. The throttling timing chamber 104 is at normal atmospheric pressure. The two-way valve ball 111 is in an open state (the two-way valve unit is conducting) under the action of the outer spring 112 and the inner spring 114. In the negative pressure connected state, the second negative pressure actuating channel V2 is connected to the negative pressure air source, and the valve ball 113 of the two-way valve presses against the sealing ring 111 against the action of the inner spring 114, and the two-way valve is in a closed state.

[0031] The throttling channel 122 in the throttling timing unit 12 is a channel with a very small gap (width of the flow-through surface), which exerts a resistance and current-limiting effect on the passing air flow. By adjusting the throttling adjustment knob (or plunger) 124 threadedly connected to the housing, the length of the resistance section can be changed to change the resistance, and thus change the time (or flow rate) for the atmosphere to enter the throttling timing cavity 104 through the second atmosphere channel A2, realizing the timing function.

[0032] II. Limit Locking Module There is one annular protrusion on the negative pressure actuating valve core 201. There is an annular groove (or ring groove) on each of the upper and lower sides of the annular protrusion, forming the first limit lock (or the first limit locking structure) 206 and the second limit lock (or the second limit locking structure) 207. In the initial state, the locking ball 203 locks the first limit lock 206. The compression degree of the locking spring 205 can be adjusted by rotating the locking adjustment knob (or locking adjustment plug) 204, and thus the pressing force of the locking ball 203 can be adjusted.

[0033] The negative pressure actuating valve core 201 can move downward under the push of the liquid level valve core 106, so that the annular protrusion on the negative pressure actuating valve core 201 passes over the locking ball 203. When the highest point of the annular protrusion on the negative pressure actuating valve core 201 (the point with the highest protrusion degree, that is, the part with the largest diameter in the annular protrusion) passes over the locking ball 203, the negative pressure actuating valve core 201 will suddenly accelerate downward and quickly move to the position where the locking ball 203 locks the second limit lock 207, and then the matching module (negative pressure actuating module) quickly changes its position (quickly switches to the negative pressure connection state).

[0034] After the liquid level valve core 106 moves upward and returns to its position, the negative pressure actuating valve core 201 moves upward and returns to its position under the action of the second spring 202. Similar to the previous process, when the highest point of the annular protrusion on the negative pressure actuating valve core 201 passes over the locking ball 203, the negative pressure actuating valve core 201 will suddenly accelerate upward and quickly move to the position where the locking ball 203 locks the first limit lock 206, and then the matching module (negative pressure actuating module) quickly changes its position (quickly switches to the negative pressure disconnection state), that is, returns to the initial state.

[0035] III. Negative Pressure Actuating Module In the initial state, the position of the negative pressure actuating valve core 201 is locked by the locking ball 203 at the first limit lock 206 position. The second annular seal 304 is sealed with the negative pressure actuating valve core 201, and the negative pressure actuating cavity 303 and the negative pressure source cavity 305 are separated. There is a gap between the first annular seal 302 and the negative pressure actuating valve core 201, and the negative pressure actuating cavity 303 communicates with the atmosphere cavity 301, that is, communicates with the third atmosphere channel A3. The air pressure control end of the negative pressure actuating mechanism is in a cut-off state with the negative pressure gas source, that is, the negative pressure actuating mechanism is turned off.

[0036] When the liquid level trigger module is in the open state, the negative pressure actuator spool 201 is pushed by the liquid level spool 106 to the second limit lock position 207. There is a gap between the second annular seal 304 and the negative pressure actuator spool 201. At the same time, the first annular seal 302 is sealed with the negative pressure actuator spool 201. The negative pressure actuator chamber 303 communicates with the negative pressure source chamber 305. At the same time, the negative pressure actuator chamber 303 is isolated from the atmosphere chamber 301. The negative pressure air source interface P of the pneumatic control valve is connected to the negative pressure actuator interface V. The air pressure control end of the negative pressure actuator is connected to the negative pressure of the negative pressure source, so that the negative pressure actuator is opened, and the sewage in the water collection tank is pumped through the negative pressure pipeline. After the air enters the drain pipe, it enters the throttling timing state. After the timing is completed, the negative pressure actuator module is turned off and the negative pressure actuator is closed.

[0037] One end of the negative pressure detection unit 31 is connected to the negative pressure air source interface P, and the other end is connected to the negative pressure source chamber 305. If the pressure difference between the two sides of the valve ball 312 of the negative pressure detection unit is less than the pressing force of the spring 313, the valve ball 312 is pressed and sealed with the sealing ring 311 under the action of the spring 313, and the negative pressure detection unit is closed, that is, the negative pressure air source interface P is closed, and the connection with the negative pressure air source is cut off; if the pressure difference between the two sides of the valve ball 312 of the negative pressure detection unit is greater than the pressing force of the spring 313, the valve ball 312 is separated from the seal between the sealing rings 311, and the negative pressure detection unit is opened, and the negative pressure air source interface P is conducted to realize the connection with the negative pressure air source.

[0038] At Figure 1 In the usage mode shown, the specific working process of this pneumatic control valve is roughly as follows: The collected sewage enters the water collection tank 3 by gravity flow. The liquid level rises and closes the lower end of the induction pipe 4. The induction pipe 4 is connected to the liquid level interface L of the pneumatic control valve through the induction pipe connecting pipe 5. When the liquid level rises to a certain height H, the internal pressure of the induction pipe 4 is transmitted to the pneumatic control valve 1, thereby triggering the pneumatic control valve 1 to open, and connecting the negative pressure to the air pressure control end of the negative pressure actuator 2, so that the negative pressure actuator 2 is opened. Under the suction of the negative pressure, the sewage in the water collection tank 3 is discharged through the drain pipe 6. When the sewage is discharged to (the water level drops to) the lowest end of the drain pipe 6, the atmosphere begins to enter the drain pipe 6. When flowing through the negative pressure source air intake port 8, the negative pressure in the negative pressure source connecting pipe 9 drops, and the negative pressure detection unit 31 of the pneumatic control valve 1 is closed, which is equivalent to the closing of the negative pressure air source, and the throttling timing starts. The atmosphere enters the throttling timing chamber 104 through the second atmosphere channel A2. The negative pressure in the chamber decreases, and the two-way valve unit 11 opens, so that the atmosphere directly enters the timing chamber 104 through the atmosphere channel A1, and the chamber 104 becomes an atmospheric pressure state. Under the action of the first spring 107, the liquid level spool 106 returns to its original position. At the same time, the negative pressure actuator spool 201 returns to its original position, and the pneumatic control valve is closed (switches the working position), cutting off the negative pressure air source at the air pressure control end of the negative pressure actuator and making it communicate with the atmosphere channel A3, and the negative pressure actuator is closed.

[0039] The starting point of throttling timing is when all the sewage has flowed through the air intake port 8 of the negative pressure air source. The air intake port 8 of the negative pressure air source is usually set near the outlet of the negative pressure actuator 2 (the outlet side when transporting sewage), and at this time, the atmosphere begins to enter the negative pressure pipeline 7. By throttling timing, it can ensure that the amount of gas entering the negative pressure pipeline 7 is fixed after each sewage discharge.

[0040] According to the prior art, sealing rings or other sealing materials can be set at the connection parts that need to be sealed. According to actual needs, rabbets (mutually matching stepped / annular stepped structures) or other connection structures that are beneficial to stability and sealing can be set at the pipe orifice-shaped connection parts (for example, between the cylindrical outer wall ports of adjacent cavities), and structures for fixing or embedding the sealing rings can be set. Threaded connections (such as screws) or other suitable connection methods can be used to fix the mutually fixed connecting parts. The size of the central through hole of each annular seal is adapted to the outer diameter of the corresponding valve core (or other cylindrical parts that form a sealing pair with it), and usually, elastic materials (such as rubber) should be used for preparation (but non-elastic structures are allowed to be set in areas where elastic deformation is not required according to actual needs). It is sleeved on the corresponding valve core through the central through hole. When the valve core is in the corresponding sealing position (the position when the sealing pair formed with this seal is in a closed state), the outer diameter of the valve core located in the central through hole of this seal should be appropriately larger than the aperture of the central through hole of this seal (the aperture in the free state), so that the hole wall of the central through hole of the seal tightly adheres / grips on the outer circle of the valve core. When the corresponding valve core is in the corresponding non-sealing position (the position when the sealing pair formed with this seal is in an open state, or called the open position), the outer diameter of the valve core located in the central through hole of this seal is smaller than the aperture of the central through hole of this seal, so that there is a gap between the hole wall of the central through hole of the seal and the outer circle of the valve core to allow the medium (such as air) to pass through. The same valve core (cylindrical part) can form multiple sealing pairs with multiple valve seat seals, and the outer diameter size of each area of the valve core can be set according to the required states of each sealing pair. When the valve core is in different set positions (for example, moved to different set positions by axial / vertical movement methods), each sealing pair synchronously switches to the state of the valve core in the corresponding position, thereby realizing the synchronization of relevant sealing pairs, which not only simplifies the structure of each sealing pair but also ensures the reliability of the synchronous switching of each sealing pair.

[0041] Diaphragms, sealing rings, springs, etc. that require deformation are made of corresponding elastic materials, while the housing, valve core, interfaces (connecting short pipes), etc. that do not require deformation can be made of hard materials, such as hard rubber and plastic materials or alloy materials suitable for humid environments.

[0042] See Figure 12, the outer edge (or periphery) of elastic components such as diaphragms and seals can be fixedly installed in any suitable manner. For example, an annular groove for embedding, clamping, or holding the component to be installed can be provided on the component 133 used as the installation base, and an installation structure 131 conforming to the annular groove can be provided on the outer edge of the component to be installed (such as a seal or a diaphragm, especially a component to be installed made of elastic material). The installation structure is placed into the annular groove, and the installation structure is pressed by a pressing plate (or other fixing component) 132, and the pressing plate is fixed (for example, fixed by fastening screws).

[0043] The present invention has the following characteristics: 1) Working mode: pneumatic, non-contact start trigger for liquid level; 2) It has a negative pressure detection function, and the negative pressure detection unit is closed when the negative pressure is insufficient; 3) It has a timing shutdown function, and the timing starts after all the sewage passes through the negative pressure actuator; 4) It has a limit locking function to avoid the phenomenon of spool commutation creep; 5) It has a manual start function.

[0044] All the preferred and optional technical means disclosed in the present invention can be arbitrarily combined to form several different specific implementation manners, unless otherwise specified or when one preferred or optional technical means is a further limitation of another technical means.

Claims

1. A liquid level-triggered negative pressure pneumatic control valve, characterized in that There are a liquid level positive pressure chamber, a throttling timing chamber, an atmosphere chamber, a negative pressure actuator chamber, and a negative pressure source chamber arranged vertically in sequence. The liquid level positive pressure chamber and the throttling timing chamber are separated by a liquid level diaphragm. The liquid level positive pressure chamber is provided with a liquid level interface, the atmosphere chamber is provided with an atmosphere interface, the negative pressure actuator chamber is provided with a negative pressure actuator mechanism interface, and the negative pressure source chamber is provided with a negative pressure gas source interface. A first annular seal is provided at the center of the separation structure between the atmosphere chamber and the negative pressure actuator chamber, and a second annular seal is provided at the center of the separation structure between the negative pressure actuator chamber and the negative pressure source chamber. The negative pressure actuator spool is arranged vertically, passes through the central through holes of the first annular seal and the second annular seal, and forms a first valve seal pair and a second valve seal pair with the first annular seal and the second annular seal respectively. When the negative pressure actuator spool is at a high position, the first valve seal pair is opened and the second valve seal pair is closed. When the negative pressure actuator spool is at a low position, the first valve seal pair is closed and the second valve seal pair is opened. The liquid level spool is arranged vertically, its upper part is fixedly connected to the center of the liquid level diaphragm, and the lower end extends out of the throttling timing chamber and is connected to the top of the negative pressure actuator spool. The liquid level spool and the negative pressure actuator spool are respectively provided with a first spring and a second spring serving as their respective return springs. The first negative pressure actuator channel communicating with the negative pressure actuator chamber is communicated with the second negative pressure actuator channel communicating with the throttling timing chamber.

2. The liquid level-triggered negative pressure pneumatic control valve according to claim 1, wherein A two-way valve unit is arranged on the side wall of the throttling timing chamber. The two-way valve unit is provided with a valve seal pair that closes when the pressure difference between the outside and the inside exceeds the limit.

3. The liquid level-triggered negative pressure pneumatic control valve according to claim 2, wherein The two-way valve unit is provided with a two-way valve medium channel. The inner end of the two-way valve medium channel opens into the throttling timing chamber, and the outer port communicates with the atmosphere. The two-way valve medium channel is provided with a two-way valve ball, a two-way valve seal ring, a two-way valve outer spring, and a two-way valve inner spring. The two-way valve seal ring is installed on the two-way valve medium channel inside the two-way valve ball and forms a valve seal pair that closes when the pressure difference between the outside and the inside exceeds the limit with the two-way valve ball. The two-way valve outer spring and the two-way valve inner spring are respectively located outside and inside the two-way valve ball, with one end acting on the valve ball and the other end acting on the two-way valve medium channel. When the valve ball is not affected by other external forces, the outer spring and the inner spring make the valve ball located in the middle of the medium channel. When the difference between the outside air pressure and the inside air pressure is less than the set limit value, the two-way valve ball does not contact the two-way valve seal ring. When the difference between the outside air pressure and the inside air pressure exceeds the set limit value, the valve ball moves inward under the combined action of the pressure difference and the two springs to a position where it is in sealed contact with the two-way valve seal ring.

4. The liquid level-triggered negative pressure pneumatic control valve according to any one of claims 1-3, characterized in that A throttling timing unit is arranged on the side wall of the throttling timing chamber. The throttling timing unit is provided with a throttling medium channel. The inner end of the throttling medium channel opens into the throttling timing chamber to form a throttling outlet, and the outer port of the throttling medium channel communicates with the atmosphere to form a throttling inlet.

5. The liquid level-triggered negative pressure pneumatic control valve according to claim 4, wherein The throttling timing unit is provided with a timing adjustment knob for adjusting the throttling resistance.

6. The liquid level-triggered negative pressure pneumatic control valve according to claim 5, characterized in that The side wall of the throttling timing chamber is provided with throttling timing holes. The outer end of the throttling timing holes is provided with internal threads. The front part of the timing adjustment knob is located inside the throttling timing holes, and there is an annular gap forming a throttling medium passage between the timing adjustment knob and the throttling timing holes. The rear part of the timing adjustment knob is provided with external threads and is threadedly connected to the internal threads on the throttling timing holes. The hole wall of the throttling timing holes is provided with side wall through holes forming throttling inlets. The inner end of the side wall through holes communicates with the annular gap between the front part of the timing adjustment knob and the throttling timing holes, and the outer end communicates with the atmosphere.

7. The liquid level-triggered negative pressure pneumatic control valve according to claim 1, wherein The liquid level diaphragm is of a rotating curved surface shape, and its middle part in the radial direction bulges downward.

8. The liquid level-triggered negative pressure pneumatic control valve according to claim 1, characterized in that The bottom surface of the throttling timing chamber is provided with a liquid level valve core through hole and a liquid level valve core seal. The liquid level valve core seal is an annular seal, and its periphery is hermetically connected to the bottom surface of the throttling timing chamber. The liquid level valve core passes through the central through hole of the liquid level valve core seal and the liquid level valve core through hole and is hermetically connected to the central through hole of the liquid level valve core seal.

9. The liquid level-triggered negative pressure pneumatic control valve according to any one of claims 1-8, characterized in that One or more limit locking mechanisms are provided in the upper part of the atmosphere chamber. The housing of the limit locking mechanism is provided with a radially extending limit locking channel. A locking ball and a locking spring are provided in the limit locking channel. The locking spring is located outside the locking ball, and its inner end acts on the locking ball to push the locking ball inward. There are two upper and lower limit locking annular grooves corresponding to the locking ball on the negative pressure actuating valve core. An annular protrusion is between the two limit locking annular grooves. The lower limit locking annular groove restricts the negative pressure actuating valve core in its high position, and the upper limit locking annular groove restricts the negative pressure actuating valve core in its low position.

10. The liquid level-triggered negative pressure pneumatic control valve according to claim 9, characterized in that The outer end of the limit locking channel is threadedly connected with a locking adjustment knob, and the outer end of the locking spring abuts against the locking adjustment knob.

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